Deep-seated salt dissolution in the Delaware basin, Texas and New Mexico

International Nuclear Information System (INIS)

Anderson, R.Y.

1981-01-01

Patterns of salt dissolution in the Delaware Basin are related to the bedrock geometry and hydrology that developed following uplift, tilting, and erosion in the late Cenozoic, and the greatest volume of salt has been removed since that time. During the Permian, some salt was dissolved from the top of the Castile Formation before deposition of the Salado Formation and from the top of the Salado before deposition of the Rustler Formation. In addition, some salt dissolution occurred after the Permian and before the Cretaceous. Post-uplift surface dissolution has progressed across the Delaware Basin from south to north and west to east and generally down the regional dip. Deep-seated dissolution has occurred around the margin of the basin where the Capitan Limestone aquifer is in contact with the Permian evaporites and within the basin where selective dissolution in the lower Salado has undercut the overlying salt beds of the middle and upper Salado. Dissolution has not advanced down regional dip uniformly but has left outliers of salt and has progressed selectively into structurally predisposed areas. This selective advance has significance for the stability of the U.S. Department of Energy's Waste Isolation Pilot Plant (WIPP) site

Investigations on boron isotopic geochemistry of salt lakes in Qaidam basin, Qinghai

Digital Repository Service at National Institute of Oceanography (India)

Xiao, Y; Shirodkar, P.V.; Liu, W.G.; Wang, Y; Jin, L.

of brine and are related to boron origin, the corrosion of salt and to certain chemical constituents. The distribution of boron isotopes in Quidam Basin showed a regional feature: salt lake brines in the west and northwest basin have the highest d11B values...

Repository site data and information in bedded salt: Palo Duro Basin, Texas

International Nuclear Information System (INIS)

Tien, P.; Nimick, F.B.; Muller, A.B.; Davis, P.A.; Guzowski, R.V.; Duda, L.E.; Hunter, R.L.

1983-11-01

This report is a compilation of data from the literature on the Palo Duro Basin. The Palo Duro Basin is a structural basin, about 150 miles long and 80 miles wide, that is a part of the much larger Permian Basin. The US Department of Energy is investigating the Palo Duro Basin as a potentially suitable area for the site of a repository for the disposal of high-level radioactive waste. Sediments overlying the Precambrian basement range from about 5000 to about 11,000 ft in thickness and from Cambrian to Holocene in age. The strata in the Palo Duro Basin that are of primary interest to the Department of Energy are the bedded salts of the Permian San Andres Formation. The total thickness of the bedded salts is about 2000 ft. The geology of the Palo Duro Basin is well understood. A great deal of information exists on the properties of salt, although much of the available information was not collected in the Palo Duro Basin. Mineral resources are not currently being exploited from the center of the Palo Duro Basin at depth, although the possibility of exploration for and development of such resources can not be ruled out. The continued existence of salts of Permian age indicates a lack of any large amount of circulating ground water. The hydrology of the pre-Tertiary rocks, however, is currently too poorly understood to carry out detailed, site-specific hydrologic modeling with a high degree of confidence. In general, ground water flows from west to east in the Basin. There is little or no hydraulic connection between aquifers above and below the salt sequences. Potable water is pumped from the Ogallala aquifer. Most of the other aquifers yield only nonpotable water. More extensive hydrological data are needed for detailed future modeling in support of risk assessment for a possible repository for high-level waste in the Palo Duro Basin. 464 references

Reinterpretation of Halokinetic Features in the Ancestral Rocky Mountains Paradox Salt Basin, Utah and Colorado

Science.gov (United States)

Thompson, J. A.; Giles, K. A.; Rowan, M. G.; Hearon, T. E., IV

2016-12-01

The Paradox Basin in southeastern Utah and southwestern Colorado is a foreland basin formed in response to flexural loading by the Pennsylvanian-aged Uncompaghre uplift during the Ancestral Rocky Mountain orogen. Thick sequences of evaporites (Paradox Formation) were deposited within the foreland basin, which interfinger with clastic sediments in the foredeep and carbonates around the basin margin. Differential loading of the Pennsylvanian-Jurassic sediments onto the evaporites drove synsedimentary halokinesis, creating a series of salt walls and adjacent minibasins within the larger foreland basin. The growing salt walls within the basin influenced patterns of sediment deposition from the Pennsylvanian through the Cretaceous. By integrating previously published mapping with recent field observations, mapping, and subsurface interpretations of well logs and 2D seismic lines, we present interpretations of the timing, geometry, and nature of halokinesis within the Paradox Basin, which record the complex salt tectonic history in the basin. Furthermore, we present recent work on the relationships between the local passive salt history and the formation of syndepositional counter-regional extensional fault systems within the foreland. These results will be integrated into a new regional salt-tectonic and stratigraphic framework of the Paradox Basin, and have broader implications for interpreting sedimentary records in other basins with a mobile substrate.

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

Permian salt dissolution, alkaline lake basins, and nuclear-waste storage, Southern High Plains, Texas and New Mexico

International Nuclear Information System (INIS)

Reeves, C.C. Jr.; Temple, J.M.

1986-01-01

Areas of Permian salt dissolution associated with 15 large alkaline lake basins on and adjacent to the Southern High Plains of west Texas and eastern New Mexico suggest formation of the basins by collapse of strata over the dissolution cavities. However, data from 6 other alkaline basins reveal no evidence of underlying salt dissolution. Thus, whether the basins were initiated by subsidence over the salt dissolution areas or whether the salt dissolution was caused by infiltration of overlying lake water is conjectural. However, the fact that the lacustrine fill in Mound Lake greatly exceeds the amount of salt dissolution and subsidence of overlying beds indicates that at least Mound Lake basin was antecedent to the salt dissolution. The association of topography, structure, and dissolution in areas well removed from zones of shallow burial emphasizes the susceptibility of Permian salt-bed dissolution throughout the west Texas-eastern New Mexico area. Such evidence, combined with previous studies documenting salt-bed dissolution in areas surrounding a proposed high-level nuclear-waste repository site in Deaf Smith County, Texas, leads to serious questions about the rationale of using salt beds for nuclear-waste storage

Distribution and abundance of Artemia salina in the Salt Lake Basin (Central Anatolia, Turkey

Directory of Open Access Journals (Sweden)

Alaş Ali

2017-06-01

Full Text Available In this study, the distribution and abundance of Artemia salina in 10 different stations of the Salt Lake basin were investigated. In addition, its relationship to pH, dissolved oxygen, temperature, electrical conductivity and water levels were analyzed. Field studies were carried out from July to August of 2010. Artemia salina was observed in five of these stations. Artemia salina was not seen in some stations that have high electrical conductivity. It is determined that, in the station named Tersakan Lake where electrical conductivity was 154 mS/cm, Artemia salina is more abundant when compared to the other stations. But as underground water pumps that are built for the irrigation of agricultural lands decrease water levels, Artemia salina’s life is under threat.

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

Energy Technology Data Exchange (ETDEWEB)

Hovorka, Susan D.; Nava, Robin

2000-06-13

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

Chapter 2. Assessment of undiscovered conventional oil and gas resources--Upper Jurassic-Lower Cretaceous Cotton Valley group, Jurassic Smackover interior salt basins total petroleum system, in the East Texas basin and Louisiana-Mississippi salt basins provinces.

Science.gov (United States)

Dyman, T.S.; Condon, S.M.

2006-01-01

The Jurassic Smackover Interior Salt Basins Total Petroleum System is defined for this assessment to include (1) Upper Jurassic Smackover Formation carbonates and calcareous shales and (2) Upper Jurassic and Lower Cretaceous Cotton Valley Group organic-rich shales. The Jurassic Smackover Interior Salt Basins Total Petroleum System includes four conventional Cotton Valley assessment units: Cotton Valley Blanket Sandstone Gas (AU 50490201), Cotton Valley Massive Sandstone Gas (AU 50490202), Cotton Valley Updip Oil and Gas (AU 50490203), and Cotton Valley Hypothetical Updip Oil (AU 50490204). Together, these four assessment units are estimated to contain a mean undiscovered conventional resource of 29.81 million barrels of oil, 605.03 billion cubic feet of gas, and 19.00 million barrels of natural gas liquids. The Cotton Valley Group represents the first major influx of clastic sediment into the ancestral Gulf of Mexico. Major depocenters were located in south-central Mississippi, along the Louisiana-Mississippi border, and in northeast Texas. Reservoir properties and production characteristics were used to identify two Cotton Valley Group sandstone trends across northern Louisiana and east Texas: a high-permeability blanket-sandstone trend and a downdip, low-permeability massive-sandstone trend. Pressure gradients throughout most of both trends are normal, which is characteristic of conventional rather than continuous basin-center gas accumulations. Indications that accumulations in this trend are conventional rather than continuous include (1) gas-water contacts in at least seven fields across the blanket-sandstone trend, (2) relatively high reservoir permeabilities, and (3) high gas-production rates without fracture stimulation. Permeability is sufficiently low in the massive-sandstone trend that gas-water transition zones are vertically extensive and gas-water contacts are poorly defined. The interpreted presence of gas-water contacts within the Cotton Valley

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

Interpretation of seismic reflection data, Central Palo Duro Basin: Technical report

International Nuclear Information System (INIS)

1986-11-01

Seismic reflection data from the Central Palo Duro Basin, Texas, were studied to identify and characterize geologic structure, potential hydrocarbon traps, and anomalies suggesting adverse features such as salt dissolution or diapirism. The data included seismic reflection data, geologic and geophysical data controlled by Stone and Webster Engineering Corporation, and data from the literature. These data comprised approximately 590 line-mi of seismic profiles over approximately 4000 mi 2 , plus well logs from 308 wells. The study addressed the section from shallow reflectors down to basement. Structural contour maps were prepared for the Upper San Andres, Near Top of Glorieta, Wolfcamp, and Precambrian horizons. Isopach maps were prepared for intervals between the Upper and Lower San Andres and between the Upper San Andres and the Wolfcamp. Interpretation indicates southeasterly dips in the northwest part of the mapped area and southwesterly dips in the southwest part. Geologic structures show a generally northwest alignment. Faults at the Precambrian level and geologic structures show a generally northwest alignment. Faulting in the area is largely limited to the Precambrian, but interpretation is uncertain. Evidence of post-Wolfcampian faulting is not recognized. Seismic data delineating the San Andres section indicate a stable section throughout the area. Anomalous reflection events possibly associated with subsurface salt dissolution were seen at the 800- to 1200-ft level in Swisher County. Other anomalies include an overthickened zone northwest of Westway and carbonate buildup in the Wolfcamp and Pennsylvanian in Randall County. Mississippian to Middle Pennsylvanian diastrophism resulting in the Amarillo Uplift and Matador Arch is not manifested structurally in the central Palo Duro Basin. Subsidence or gentle uplift contributed to some structural deformation

Water in urban planning, Salt Creek Basin, Illinois water management as related to alternative land-use practices

Science.gov (United States)

Spieker, Andrew Maute

1970-01-01

regarded as an area of potential recharge to the shallow aquifers. Preservation of the effectiveness of these potential recharge areas should be considered in land-use planning. Salt Creek is polluted in times of both low and high flow. Most communities in the basin in Du Page County discharge their treated sewage into the creek, whereas those in Cook County transfer their sewage to plants of the Metropolitan Sanitary District outside the basin. During periods of high runoff, combined storm runoff and overflow from sanitary sewers enter the creek. Such polluted water detracts from the stream's esthetic and recreational potential and poses a threat to ground-water supplies owing to induced recharge of polluted water to shallow aquifers. Alternative approaches .to the pollution problem include improvement of the degree of sewage treatment, detention and treatment of storm runoff, dilution of sewage through flow augmentation, or transfer of sewage from the basin to a central treatment plant. To result in an enhanced environment, the streambed would have to be cleansed of accumulated sludge deposits. The overbank flooding in Salt Creek basin every 2 to 3 years presents problems because of encroachments and developments on the flood plains. Flood plains in an urban area can be managed by identifying them, by recognizing that either their natural storage capacity or equivalent artificial capacity is needed to accommodate floods, and by planning land use accordingly. Examples of effective floodplain management include (1) preservation of greenbelts or regional parks along stream courses, (2) use of flood plains for recreation, parking lots. or other low-intensity uses, (3) use of flood-proofed commercial buildings, and (4) provision for compensatory storage to replace natural storage capacity. Results of poor flood-plain management include uncontrolled residential development and encroachment by fill into natural storage areas where no compensatory storage has been

Magnetostratigraphy and 230Th dating of a drill core from the southeastern Qaidam Basin: Salt lake evolution and tectonic implications

Directory of Open Access Journals (Sweden)

An-Dong Chen

2018-05-01

Full Text Available The Qarhan Salt Lake area is the Quaternary depocenter of the Qaidam Basin, and carries thick lacustrine sediments, as well as rich potassium and magnesium salt deposits. The abundant resources and thick sediments in this lake provide an ideal place for the study of biogas formation and preservation, salt lake evolution, and the uplift of the Tibetan Plateau. In this study, we attempt to construct a paleomagnetic and 230Th age model and to obtain information on tectonic activity and salt lake evolution through detailed studies on a 1300-m-long drill core (15DZK01 from the northwestern margin of the Qarhan Salt Lake area (Dongling Lake. Based on gypsum 230Th dating, the age of the uppermost clastic deposit was calculated to be around 0.052 Ma. The polarity sequence consist of 13 pairs of normal and reversed zones, which can be correlated with subchrons C2r.1r-C1n of the geomagnetic polarity timescale (GPTS 2012 (from ∼2.070 Ma to ∼0.052 Ma. Sedimentary characteristics indicate that Dongling Lake witnessed freshwater environment between ∼2.070 Ma and 1.546 Ma. During this period, the sedimentary record reflects primarily lakeshore, shallow-water and swamp environments, representing favourable conditions for the formation of hydrocarbon source rocks. Between 1.546 Ma and ∼0.052 Ma, the Dongling Lake was in sulphate deposition stage, which contrasts with the central Qarhan Salt Lake area, where this stage did not occur in the meantime. During this stage, Dongling Lake was in a shallow saltwater lake environment, but several periods of reduced salinity occurred during this stage. During the late Pleistocene at ∼0.052 Ma, the Dongling Lake experienced uplift due to tectonic activity, and saltwater migrated through the Sanhu Fault to the central Qarhan Salt Lake area, resulting in the absence of halite deposition stage. The residual saline water was concentrated into magnesium-rich brine due to the lack of freshwater, and few

The Transylvanian Basin (Romania) and its relation to the Carpathian fold and thrust belt: Insights in gravitational salt tectonics

Energy Technology Data Exchange (ETDEWEB)

Krezsek, Csaba [SNGN ROMGAZ, 4 Unirii 551025 Medias (Romania); Bally, Albert W. [Department of Geology and Geophysics, University of Rice, 6100 South Main Street, Houston, TX 77005-1892 (United States)

2006-05-15

Interpretation of regional seismic profiles, stratigraphic and sedimentologic data improved insights in the evolution of the Transylvanian Basin. The basin evolution was coeval with the post-Mid-Cretaceous to recent deformation of the Carpathian Mts. Four tectonostratigraphic megasequences are differentiated: Upper Cretaceous (rift), Paleogene (sag), Lower Miocene (flexural basin) and Middle to Upper Miocene (backarc sequence dominated by gravitational tectonics). The Mid-Miocene continental collision in the Eastern Carpathians is associated with the rising Carpathians. This uplift enhanced the differential load, which, together with the high heat flow induced by Late Miocene to Pliocene arc volcanism, triggered large-scale Mio-Pliocene gravity spreading of the salt overburden. This 'mega-slide' comprises three structural domains, as follows: extensional weld (upslope), contractional folds (central) and contractional toe thrust (downslope). The diapirs in the east indicate a pre-shortening reactive/passive growth stage. The central folds are mostly the result of late shortening. Basement involved thrusting uplifted the toe thrust domain by the Late Pliocene. The Late Neogene to recent Carpathians uplift, backarc volcanism and gravity spreading are largely coeval. (author)

Limnology and plankton diversity of salt lakes from Transylvanian Basin (Romania: A review

Directory of Open Access Journals (Sweden)

Mircea Alexe

2017-09-01

Full Text Available In the present work, we review the current knowledge on genesis, limnology and biodiversity of salt lakes distributed around the inner contour of Eastern Carpathian arc (Transylvanian Basin, Central Romania. Transylvanian salt lakes formed on ancient halite (NaCl deposits following natural processes or quarrying activities.  Most of these lakes are located in eastern (Sovata area, southern (Ocna Sibiului, and western (Turda-Cojocna parts of the Transylvanian Basin, have small surfaces (0.1-4 ha, variable depths (2-100 m, are hypersaline (>10%, w/v, total salts, mainly NaCl and permanently stratified. As consequence of steady salinity/density gradient, heat entrapment below surface layer (i.e., heliothermy develops in several Transylvanian lakes. The physical and chemical water stratification is mirrored in the partition of plankton diversity. Lakes with less saline (2-10% salinity water layers appear to harbor halotolerant representatives of phyto- (e.g., marine native Picochlorum spp. and Synechococcus spp., zoo- (e.g., Moina salina, and bacterioplankton (e.g., Actinobacteria, Verrucomicobia, whereas halophilic plankton communities (e.g., green algae Dunaliella sp., brine shrimp Artemia sp., and members of Halobacteria class dominate in the oxic surface of hypersaline (>10% salinity lakes. Molecular approaches (e.g., PCR-DGGE, 16S rRNA gene-based clone libraries, and DNA metabarcoding showed that the O2-depleted bottom brines of deep meromictic Transylvanian lakes are inhabited by known extremely halophilic anaerobes (e.g. sulfate-reducing Delta-Proteobacteria, fermenting Clostridia, methanogenic and polymer-degrading archaea in addition to representatives of uncultured/unclassified prokaryotic lineages. Overall, the plankton communities thriving in saline Transylvanian lakes seem to drive full biogeochemical cycling of main elements. However, the trophic interactions (i.e., food web structure and energy flow as well as impact of human

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.

Dissolution of the Upper Seven Rivers and Salado salt in the interior Palo Duro Basin, Texas: Revision: Topical report

International Nuclear Information System (INIS)

DeConto, R.T.; Murphy, P.J.

1987-09-01

The Upper Seven Rivers and Salado Formations contain the uppermost salts within the interior Palo Duro Basin, Stratigraphic and structural evidence based on geophysical well logs indicate that both dissolution and facies change have influenced the thickness of these uppermost salts. The magnitude of vertical salt loss due to dissolution is interminable at this time because original salt thickness is unknown. Gradual thinning of the Upper Seven Rivers Formation is recognized from south to north across the Palo Duro Basin. Anhydrites within the formation pinch out toward the basin margins, indicating that section loss is in part depositionally controlled. Additionally, informal subdivision of the Upper Seven Rivers Formation suggests that salt dissolution has occurred in the uppermost salt. A northeast-trending zone of thin Upper Seven Rivers Formation in portions of Deaf Smith, Randall, Castro, and Parmer Counties is possibly related to Tertiary dissolution. In New Mexico, local thinning of the Upper Seven Rivers Formation may be associated with faulting. Triassic erosion on uplifted fault blocks has affected the Upper Permian section. The Salado salt margin is located within the interior Palo Duro Basin. Geophysical well logs and core evidence indicate that the salt margin has migrated basinward as a result of dissolution. Permian dissolution probably contributed to some salt loss. 106 refs., 31 figs., 2 tabs

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

Detailed bathymetric surveys in the central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Kodagali, V.N.; KameshRaju, K.A.; Ramprasad, T.; George, P.; Jaisankar, S.

Over 420,000 line kilometers of echo-sounding data was collected in the Central Indian Basin. This data was digitized, merged with navigation data and a detailed bathymetric map of the Basin was prepared. The Basin can be broadly classified...

Assessment of selected inorganic constituents in streams in the Central Arizona Basins Study Area, Arizona and northern Mexico, through 1998

Science.gov (United States)

Anning, David W.

2003-01-01

Stream properties and water-chemistry constituent concentrations from data collected by the National Water-Quality Assessment and other U.S. Geological Survey water-quality programs were analyzed to (1) assess water quality, (2) determine natural and human factors affecting water quality, and (3) compute stream loads for the surface-water resources in the Central Arizona Basins study area. Stream temperature, pH, dissolved-oxygen concentration and percent saturation, and dissolved-solids, suspended-sediment, and nutrient concentration data collected at 41 stream-water quality monitoring stations through water year 1998 were used in this assessment. Water-quality standards applicable to the stream properties and water-chemistry constituent concentration data for the stations investigated in this study generally were met, although there were some exceedences. In a few samples from the White River, the Black River, and the Salt River below Stewart Mountain Dam, the pH in reaches designated as a domestic drinking water source was higher than the State of Arizona standard. More than half of the samples from the Salt River below Stewart Mountain Dam and almost all of the samples from the stations on the Central Arizona Project Canal?two of the three most important surface-water sources used for drinking water in the Central Arizona Basins study area?exceeded the U.S. Environmental Protection Agency drinking water Secondary Maximum Contaminant Level for dissolved solids. Two reach-specific standards for nutrients established by the State of Arizona were exceeded many times: (1) the annual mean concentration of total phosphorus was exceeded during several years at stations on the main stems of the Salt and Verde Rivers, and (2) the annual mean concentration of total nitrogen was exceeded during several years at the Salt River near Roosevelt and at the Salt River below Stewart Mountain Dam. Stream properties and water-chemistry constituent concentrations were related to

Implications of diapir-derived detritus and gypsic paleosols in Lower Triassic strata near the Castle Valley salt wall, Paradox Basin, Utah

Science.gov (United States)

Lawton, Timothy F.; Buck, Brenda J.

2006-10-01

Gypsum-bearing growth strata and sedimentary facies of the Moenkopi Formation on the crest and NE flank of the Castle Valley salt wall in the Paradox Basin record salt rise, evaporite exposure, and salt-withdrawal subsidence during the Early Triassic. Detrital gypsum and dolomite clasts derived from the middle Pennsylvanian Paradox Formation were deposited in strata within a few kilometers of the salt wall and indicate that salt rise rates roughly balanced sediment accumulation, resulting in long-term exposure of mobile evaporite. Deposition took place primarily in flood-basin or inland sabkha settings that alternated between shallow subaqueous and subaerial conditions in a hyperarid climate. Matrix-supported and clast-supported conglomerates with gypsum fragments represent debris-flow deposits and reworked debris-flow deposits, respectively, interbedded with flood-basin sandstone and siltstone during development of diapiric topography. Mudstone-rich flood-basin deposits with numerous stage I to III gypsic paleosols capped by eolian gypsum sand sheets accumulated during waning salt-withdrawal subsidence. Association of detrital gypsum, eolian gypsum, and gypsic paleosols suggests that the salt wall provided a common source for gypsum in the surrounding strata. This study documents a previously unrecognized salt weld with associated growth strata containing diapir-derived detritus and gypsic palesols that can be used to interpret halokinesis.

Ferromanganese nodules from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Jauhari, P.; Pattan, J.N.

In order to delineate a mine site for ferromanganese nodules, extensive surveys were conducted in Central Indian Ocean Basin. Mapping of the basin by multibeam swath bathymetry (Hydrosweep) has revealed many new bottom relief features...

Tectonic-stratigraphic evolution of mini-basins and salt provinces of Espirito Santo Basin-Brazil; Analise da evolucao tectono sedimentar de mini-bacias e provincias de sal da Bacia do Espirito Santo

Energy Technology Data Exchange (ETDEWEB)

Ferreira Neto, Walter Dias; Fernandes, Flavio Luis [Petroleum Geoscience Technology Ltda. (PGT), Rio de Janeiro, RJ (Brazil); Mohriak, Webster [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil)

2008-07-01

The Espirito Santo Basin integrates the group of basins along the eastern Brazilian continental margin. It is located between 18 deg and 21 deg S, encompassing an area of approximately 220,000 km{sup 2}, onshore and offshore the Espirito Santo State. Its geological limit with the Campos Basin to the south is defined by a Precambrian basement high (Vitoria Arch), and its northern limit with the Mucuri Basin is defined by a geopolitical limit. The study of salt tectonics processes in the Espirito Santo Basin allowed the deformational analysis and interpretation of the chronological evolution of the mini-basins developed between salt diapirs. We observe an intrinsic relationship between halokinesis and creation of subsidence troughs that may be important for trapping hydrocarbon reservoirs, and consequently form oil and gas accumulations in this portion of the basin. This geodynamics evolution of these structures is marked by a strong linkage between salt movement and coeval sedimentation in the interdomal basins, forming structures and stratigraphic traps that may constitute important aspects for the petroleum geology. (author)

Investigation of the suspected presence of solid hydrocarbon in bedded salt samples from the Palo Duro Basin, Texas

International Nuclear Information System (INIS)

1985-10-01

This report contains laboratory test results for two bedded salt samples from the Grabbe No. 1 (PD-2) Well of the Palo Duro Basin, Texas. This study was commissioned to determine whether or not solid hydrocarbons exist in bedded salt samples in the Palo Duro Basin. Laboratory investigations include electron microprobe examinations on polished thin sections and optical examinations and chemical tests on insoluble residues of the salt samples. No direct evidence was found that identifiable solid hydrocarbons are present in either sample of the bedded salt core. The total carbon content of the two salt samples was measured yielding 0.016 and 0.022 weight percent carbon. Detailed microscopic analyses showed that the carbon in the samples was associated with calcite, clays, and the epoxy resin used in sample preparation

Volcanism and Tectonics of the Central Deep Basin, Sea of Japan

Science.gov (United States)

Lelikov, E. P.; Emelyanova, T. A.; Pugachev, A. A.

2018-01-01

The paper presents the results of a study on the geomorphic structure, tectonic setting, and volcanism of the volcanoes and volcanic ridges in the deep Central Basin of the Sea of Japan. The ridges rise 500-600 m above the acoustic basement of the basin. These ridges were formed on fragments of thinned continental crust along deep faults submeridionally crossing the Central Basin and the adjacent continental part of the Primorye. The morphostructures of the basin began to submerge below sea level in the Middle Miocene and reached their contemporary positions in the Pliocene. Volcanism in the Central Basin occurred mostly in the Middle Miocene-Pliocene and formed marginal-sea basaltoids with OIB (ocean island basalt) geochemical signatures indicating the lower-mantle plume origin of these rocks. The OIB signatures of basaltoids tend to be expressed better in the eastern part of the Central Basin, where juvenile oceanic crust has developed. The genesis of this crust is probably related to rising and melting of the Pacific superplume apophyse.

Geohydrology of the Keechi, Mount Sylvan, Oakwood, and Palestine salt domes in the northeast Texas salt-dome basin

International Nuclear Information System (INIS)

Carr, J.E.; Halasz, S.J.; Peters, H.B.

1980-01-01

The salt within these domes has penetrated as much as 20,000 feet of Mesozoic and Cenozoic strata, and presently extends to within 120 to 800 feet of the land surface. The salt penetrates or closely underlies major freshwater and salinewater aquifers within the basin. To provide a safe repository for radioactive wastes within one or more of these domes, a thorough understanding of the geohydrology needs to be obtained, and the hydrologic stability of the domes needs to be established for the expected life of the storage facility. Dissolution may exist at all four candidate salt domes, possibly through contact with Cretaceous or Tertiary aquifers, or through fault systems in the vicinity of the domes. Strata overlying and surrounding Palestine and Keechi Salt Domes have been arched into steeply-dipping folds that are complexly faulted. Similar conditions exist at Oakwood and Mount Sylvan Domes, except that the Tertiary strata have been only moderately disturbed. Additional problems concerning the hydrologic stability of Oakwood and Palestine Salt Domes have resulted from the disposal of oil-field salinewater in the cap rock at the Oakwood Dome and previous solution mining of salt at the Palestine Dome

Gravity signals from the lithosphere in the Central European Basin System

Science.gov (United States)

Yegorova, T.; Bayer, U.; Thybo, H.; Maystrenko, Y.; Scheck-Wenderoth, M.; Lyngsie, S. B.

2007-01-01

We study the gravity signals from different depth levels in the lithosphere of the Central European Basin System (CEBS). The major elements of the CEBS are the Northern and Southern Permian Basins which include the Norwegian-Danish Basin (NDB), the North-German Basin (NGB) and the Polish Trough (PT). An up to 10 km thick sedimentary cover of Mesozoic-Cenozoic sediments, hides the gravity signal from below the basin and masks the heterogeneous structure of the consolidated crust, which is assumed to be composed of domains that were accreted during the Paleozoic amalgamation of Europe. We performed a three-dimensional (3D) gravity backstripping to investigate the structure of the lithosphere below the CEBS. Residual anomalies are derived by removing the effect of sediments down to the base of Permian from the observed field. In order to correct for the influence of large salt structures, lateral density variations are incorporated. These sediment-free anomalies are interpreted to reflect Moho relief and density heterogeneities in the crystalline crust and uppermost mantle. The gravity effect of the Moho relief compensates to a large extent the effect of the sediments in the CEBS and in the North Sea. Removal of the effects of large-scale crustal inhomogeneities shows a clear expression of the Variscan arc system at the southern part of the study area and the old crust of Baltica further north-east. The remaining residual anomalies (after stripping off the effects of sediments, Moho topography and large-scale crustal heterogeneities) reveal long wavelength anomalies, which are caused mainly by density variations in the upper mantle, though gravity influence from the lower crust cannot be ruled out. They indicate that the three main subbasins of the CEBS originated on different lithospheric domains. The PT originated on a thick, strong and dense lithosphere of the Baltica type. The NDB was formed on a weakened Baltica low-density lithosphere formed during the Sveco

Fluid inclusion brine compositions from Palo Duro Basin salt sites

International Nuclear Information System (INIS)

Moody, J.B.

1987-01-01

The fluid inclusion analyses were done on salt samples from Lower San Andres Cycle 4 and 5. The stable isotope composition of the fluid inclusion brines was measured on duplicate samples taken from the same fluid inclusion brine for correlation of geochemical content with the stable isotopic content. The analyzed Palo Duro Basin salt fluid inclusions are predominantly one phase, i.e., the presence of a fluid only. However, many of the larger fluid inclusions do have a small vapor bubble. This liquid/vapor ratio is so high in these vapor-containing fluid inclusions that their behavior in a thermal gradient would be almost identical to that of all liquid inclusions. Closely associated with the fluid inclusions are cryptomelane where some fibers penetrate into halite host crystal. The fluid inclusions have a wide variability in content for those components that were analyzed, even within the same salt type. The fluid inclusion brines are also acidic, ranging from 3 to 6 as measured with pH test papers

A MAP MASH-UP APPLICATION: INVESTIGATION THE TEMPORAL EFFECTS OF CLIMATE CHANGE ON SALT LAKE BASIN

Directory of Open Access Journals (Sweden)

O. S. Kirtiloglu

2016-06-01

Full Text Available The main purpose of this paper is to investigate climate change effects that have been occurred at the beginning of the twenty-first century at the Konya Closed Basin (KCB located in the semi-arid central Anatolian region of Turkey and particularly in Salt Lake region where many major wetlands located in and situated in KCB and to share the analysis results online in a Web Geographical Information System (GIS environment. 71 Landsat 5-TM, 7-ETM+ and 8-OLI images and meteorological data obtained from 10 meteorological stations have been used at the scope of this work. 56 of Landsat images have been used for extraction of Salt Lake surface area through multi-temporal Landsat imagery collected from 2000 to 2014 in Salt lake basin. 15 of Landsat images have been used to make thematic maps of Normalised Difference Vegetation Index (NDVI in KCB, and 10 meteorological stations data has been used to generate the Standardized Precipitation Index (SPI, which was used in drought studies. For the purpose of visualizing and sharing the results, a Web GIS-like environment has been established by using Google Maps and its useful data storage and manipulating product Fusion Tables which are all Google’s free of charge Web service elements. The infrastructure of web application includes HTML5, CSS3, JavaScript, Google Maps API V3 and Google Fusion Tables API technologies. These technologies make it possible to make effective “Map Mash-Ups” involving an embedded Google Map in a Web page, storing the spatial or tabular data in Fusion Tables and add this data as a map layer on embedded map. The analysing process and map mash-up application have been discussed in detail as the main sections of this paper.

a Map Mash-Up Application: Investigation the Temporal Effects of Climate Change on Salt Lake Basin

Science.gov (United States)

Kirtiloglu, O. S.; Orhan, O.; Ekercin, S.

2016-06-01

The main purpose of this paper is to investigate climate change effects that have been occurred at the beginning of the twenty-first century at the Konya Closed Basin (KCB) located in the semi-arid central Anatolian region of Turkey and particularly in Salt Lake region where many major wetlands located in and situated in KCB and to share the analysis results online in a Web Geographical Information System (GIS) environment. 71 Landsat 5-TM, 7-ETM+ and 8-OLI images and meteorological data obtained from 10 meteorological stations have been used at the scope of this work. 56 of Landsat images have been used for extraction of Salt Lake surface area through multi-temporal Landsat imagery collected from 2000 to 2014 in Salt lake basin. 15 of Landsat images have been used to make thematic maps of Normalised Difference Vegetation Index (NDVI) in KCB, and 10 meteorological stations data has been used to generate the Standardized Precipitation Index (SPI), which was used in drought studies. For the purpose of visualizing and sharing the results, a Web GIS-like environment has been established by using Google Maps and its useful data storage and manipulating product Fusion Tables which are all Google's free of charge Web service elements. The infrastructure of web application includes HTML5, CSS3, JavaScript, Google Maps API V3 and Google Fusion Tables API technologies. These technologies make it possible to make effective "Map Mash-Ups" involving an embedded Google Map in a Web page, storing the spatial or tabular data in Fusion Tables and add this data as a map layer on embedded map. The analysing process and map mash-up application have been discussed in detail as the main sections of this paper.

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.

Architectural features of the Kayenta formation (Lower Jurassic), Colorado Plateau, USA: relationship to salt tectonics in the Paradox Basin

Science.gov (United States)

Bromley, Michael H.

1991-09-01

Fluvial sandstones of the Kayenta Formation were analyzed using architectural element analysis. Paleocurrent trends, the distribution of lacustrine facies and local silcrete development indicate that synsedimentary movement of evaporites in the underlying Paradox Basin created an unstable basin floor beneath the Kayenta fluvial system. This instability resulted in deflection of fluvial axes, local basin development and local areas of interrupted fluvial deposition with eolian dunes. Paleocurrent trends in the Kayenta system reflect periodic interruptions of southwesterly flow. Salt migrating laterally out of a rim syncline into an adjacent salt anticline resulted in a rim syncline of slight topographic relief. The resulting basin was probably rapidly filled, allowing the resumption of southwesterly flow. Differential movement of salt (incipient solution collapse features (?)) resulted in the formation of small centripetal basins in which playa mudstones formed. A laterally extensive resistant ledge underlies a horizontal surface, suggestive of deflation to the water table of an exposed section of valley fill. A channel scour in the top of one of these surfaces has margins much steeper ( > 60°) than the angle of repose for unconsolidated sand. Early cementation of the exposed floodplain could account for this resistance.

Potential impact of climate change on groundwater resources in the Central Huai Luang Basin, Northeast Thailand.

Science.gov (United States)

Pholkern, Kewaree; Saraphirom, Phayom; Srisuk, Kriengsak

2018-08-15

The Central Huai Luang Basin is one of the important rice producing areas of Udon Thani Province in Northeastern Thailand. The basin is underlain by the rock salt layers of the Maha Sarakham Formation and is the source of saline groundwater and soil salinity. The regional and local groundwater flow systems are the major mechanisms responsible for spreading saline groundwater and saline soils in this basin. Climate change may have an impact on groundwater recharge, on water table depth and the consequences of waterlogging, and on the distribution of soil salinity in this basin. Six future climate conditions from the SEACAM and CanESM2 models were downscaled to investigate the potential impact of future climate conditions on groundwater quantity and quality in this basin. The potential impact was investigated by using a set of numerical models, namely HELP3 and SEAWAT, to estimate the groundwater recharge and flow and the salt transport of groundwater simulation, respectively. The results revealed that within next 30years (2045), the future average annual temperature is projected to increase by 3.1°C and 2.2°C under SEACAM and CanESM2 models, respectively, while the future precipitation is projected to decrease by 20.85% under SEACAM and increase by 18.35% under the CanESM2. Groundwater recharge is projected to increase under the CanESM2 model and to slightly decrease under the SEACAM model. Moreover, for all future climate conditions, the depths of the groundwater water table are projected to continuously increase. The results showed the impact of climate change on salinity distribution for both the deep and shallow groundwater systems. The salinity distribution areas are projected to increase by about 8.08% and 56.92% in the deep and shallow groundwater systems, respectively. The waterlogging areas are also projected to expand by about 63.65% from the baseline period. Copyright © 2018 Elsevier B.V. All rights reserved.

Composition of fluid inclusions in Permian salt beds, Palo Duro Basin, Texas, U.S.A.

Science.gov (United States)

Roedder, E.; d'Angelo, W. M.; Dorrzapf, A.F.; Aruscavage, P. J.

1987-01-01

Several methods have been developed and used to extract and chemically analyze the two major types of fluid inclusions in bedded salt from the Palo Duro Basin, Texas. Data on the ratio K: Ca: Mg were obtained on a few of the clouds of tiny inclusions in "chevron" salt, representing the brines from which the salt originally crystallized. Much more complete quantitative data (Na, K, Ca, Mg, Sr, Cl, SO4 and Br) were obtained on ??? 120 individual "large" (mostly ???500 ??m on an edge, i.e., ??? ??? 1.6 ?? 10-4 g) inclusions in recrystallized salt. These latter fluids have a wide range of compositions, even in a given piece of core, indicating that fluids of grossly different composition were present in these salt beds during the several (?) stages of recrystallization. The analytical results indicating very large inter-and intra-sample chemical variation verify the conclusion reached earlier, from petrography and microthermometry, that the inclusion fluids in salt and their solutes are generally polygenetic. The diversity in composition stems from the combination of a variety of sources for the fluids (Permian sea, meteoric, and groundwater, as well as later migrating ground-, formation, or meteoric waters of unknown age), and a variety of subsequent geochemical processes of dissolution, precipitation and rock-water interaction. The compositional data are frequently ambiguous but do provide constraints and may eventually yield a coherent history of the events that produced these beds. Such an understanding of the past history of the evaporite sequence of the Palo Duro Basin should help in predicting the future role of the fluids in the salt if a nuclear waste repository is sited there. ?? 1987.

Executive summary of a draft report on the geology and salt deposits of the Salina Salt Basin

International Nuclear Information System (INIS)

1978-01-01

The study discussed is the first phase of a program for the geologic evaluation of the Silurian-age bedded salt of the Salina Group. The Salina Salt Basin, as used in this study, includes those portions of the Appalachian and Michigan basins that are underlain by the Salina Group. The full draft report consists of a regional reconnaissance, identification of study areas in New York and Ohio which are deserving of a more thorough evaluation, and a program plan to accomplish that evaluation. The entire draft report is in two volumes, contains 1068 pages and 204 figures, and has a bibliography that consists of over 1100 separate entries. This summary has been prepared for the benefit of those who wish to review the results of this phase of the evaluation but who do not want to go through the exhaustive detail that is present in the full report. The regional reconnaissance was accomplished by a very thorough and extensive literature review, addressing the following topics: depth of salt, thickness, stratigraphy, tectonics, structure, seismicity, hydrology, erosion and denudation, and mineral resources. Before further technical evaluation proceeds, the draft report and the proposed program are being subjected to a thorough evaluation by a number of groups, including appropriate state agencies. This rather extensive review process is being conducted to ensure that the program is performed entirely in the open and subject to continuous public surveillance. This report does not represent the first work that has been done in this region with regard to evaluating the salt deposits for waste disposal. Previous efforts have been limited, however, and have been done by individual consultants. At the present time, the U.S. Geological Survey is also participating in the technical evaluation; their results will be issued separately. In addition to the technical evaluations, environmental surveys will also be conducted as an integral part of this thorough evaluation program

Miocene tectonic history of the Central Tauride intramontane basins, and the paleogeographic evolution of the Central Anatolian Plateau

Science.gov (United States)

Koç, Ayten; Kaymakci, Nuretdin; Van Hinsbergen, Douwe J. J.; Kuiper, Klaudia F.

2017-11-01

Marine Lower-Upper Miocene deposits uplifted to > 2 km elevation in the Tauride mountains of southern Turkey are taken as evidence for the rise of a nascent plateau. The dynamic causes of this uplift are debated, but generally thought to be a regional dynamic topographic effect of slab motions or slab break-off. Immediately adjacent to the high Tauride mountains lie the Central Tauride Intramontane Basins, which consist of Miocene and younger fluvio-lacustrine basins, at much lower elevations than the highly uplifted marine Miocene rocks. These basins include the previously analyzed Altınapa and Yalvaç basins, as well as the until now undescribed Ilgın Basin. In this paper, we aim to constrain the paleogeography of the Central Tauride Intramontane Basins and determine the role of the tectonics driving the formation of the high Miocene topography in southern Turkey. Therefore, we provide new data on the stratigraphy, sedimentology and structure of the continental Ilgın Basin. We provide an 40Ar/39Ar age of 11.61 ± 0.05 Ma for pumice deposits in the stratigraphy. We provide paleostress inversion analysis based on growth faults showing that the basin formed during multi-directional extension, with NE-SW to E-W dominating over subordinate Nsbnd S extension. We conclude that major, still-active normal faults like the Akşehir Fault also controlled Miocene Ilgın basin formation, with proximal facies close to the basin margins grading upwards and basinwards into lacustrine deposits representing the local depocenter. The Ilgın Basin was a local depocenter, but it may have connected with the adjacent Altınapa Basin during high lake levels in late Serravallian time. The Ilgın Basin and the other continental basins provide key constraints on the paleogeography and tectonic history of the region. These continental basins were likely close to the paleo-coastline during the Late Miocene after which there must have been major differential uplift of the Taurides. We

Corridors of crestal and radial faults linking salt diapirs in the Espírito Santo Basin, SE Brazil

Science.gov (United States)

Mattos, Nathalia H.; Alves, Tiago M.

2018-03-01

This work uses high-quality 3D seismic data to assess the geometry of fault families around salt diapirs in SE Brazil (Espírito Santo Basin). It aims at evaluating the timings of fault growth, and suggests the generation of corridors for fluid migration linking discrete salt diapirs. Three salt diapirs, one salt ridge, and five fault families were identified based on their geometry and relative locations. Displacement-length (D-x) plots, Throw-depth (T-z) data and structural maps indicate that faults consist of multiple segments that were reactivated by dip-linkage following a preferential NE-SW direction. This style of reactivation and linkage is distinct from other sectors of the Espírito Santo Basin where the preferential mode of reactivation is by upwards vertical propagation. Reactivation of faults above a Mid-Eocene unconformity is also scarce in the study area. Conversely, two halokinetic episodes dated as Cretaceous and Paleogene are interpreted below a Mid-Eocene unconformity. This work is important as it recognises the juxtaposition of permeable strata across faults as marking the generation of fault corridors linking adjacent salt structures. In such a setting, fault modelling shows that fluid will migrate towards the shallower salt structures along the fault corridors first identified in this work.

Ranking contributing areas of salt and selenium in the Lower Gunnison River Basin, Colorado, using multiple linear regression models

Science.gov (United States)

Linard, Joshua I.

2013-01-01

Mitigating the effects of salt and selenium on water quality in the Grand Valley and lower Gunnison River Basin in western Colorado is a major concern for land managers. Previous modeling indicated means to improve the models by including more detailed geospatial data and a more rigorous method for developing the models. After evaluating all possible combinations of geospatial variables, four multiple linear regression models resulted that could estimate irrigation-season salt yield, nonirrigation-season salt yield, irrigation-season selenium yield, and nonirrigation-season selenium yield. The adjusted r-squared and the residual standard error (in units of log-transformed yield) of the models were, respectively, 0.87 and 2.03 for the irrigation-season salt model, 0.90 and 1.25 for the nonirrigation-season salt model, 0.85 and 2.94 for the irrigation-season selenium model, and 0.93 and 1.75 for the nonirrigation-season selenium model. The four models were used to estimate yields and loads from contributing areas corresponding to 12-digit hydrologic unit codes in the lower Gunnison River Basin study area. Each of the 175 contributing areas was ranked according to its estimated mean seasonal yield of salt and selenium.

Evolution characteristic of gypsum-salt rocks of the upper member of Oligocene Lower Ganchaigou Fm in the Shizigou area, western Qaidam Basin

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Dinghong Yi

2017-09-01

Full Text Available Over years of oil and gas exploration in the Qaidam Basin, reservoirs have been discovered in many layers. In the Shizigou area, western Qaidam Basin, the upper member of Oligocene Lower Ganchaigou Fm is an important target for oil and gas exploration, and gypsum-salt rocks are the high-quality caprocks for the preservation of oil and gas reservoirs in this area. For predicting oil and gas exploration direction and target in the western Qaidam Basin and providing guidance for its oil and gas exploration deployment, its depositional characteristics and environment of gypsum-salt rocks in this area were investigated based on the core observation, thin section identification, and analysis of grain size, sensitivity parameter ratios (Sr/Cu, Fe/Mn, (Fe + Al/(Ca + Mg, V/(V + Ni and Pr/Ph, pyrite content and inclusions. The following characteristics are identified. First, gypsum-salt rocks are mainly distributed in the depocenter of the lake basin and their thickness decreases towards the margin of the basin. They are laterally transformed into carbonate rocks or terrigenous clastic rocks. They are areally distributed in the shape of irregular ellipse. Second, gypsum-salt rocks are vertically developed mainly in the middle and upper parts of the upper member of Lower Ganchaigou Fm and they are interbedded with carbonate rocks or terrigenous clastic rocks. Their single layer thickness changes greatly, and there are many layers with good continuity. Third, Sand Group III to Group I in the upper member of Lower Ganchaigou Fm (inter-salt are of reductive water environment of semi-deep to deep lake facies due to their sedimentation in an arid and hot climate. It is concluded that gypsum-salt rocks of the upper member of Lower Ganchaigou Fm are distributed widely with great accumulative thickness in this area; and that they are originated from deep lake water by virtue of evaporation, concentration and crystallization in an arid and hot climate instead

Dynamics of prolonged salt movement in the Glückstadt Graben (NW Germany) driven by tectonic and sedimentary processes

Science.gov (United States)

Warsitzka, Michael; Kley, Jonas; Jähne-Klingberg, Fabian; Kukowski, Nina

2017-01-01

The formation of salt structures exerted a major influence on the evolution of subsidence and sedimentation patterns in the Glückstadt Graben, which is part of the Central European Basin System and comprises a post-Permian sediment thickness of up to 11 km. Driven by regional tectonics and differential loading, large salt diapirs, salt walls and salt pillows developed. The resulting salt flow significantly influenced sediment distribution in the peripheral sinks adjacent to the salt structures and overprinted the regional subsidence patterns. In this study, we investigate the geometric and temporal evolution of salt structures and subsidence patterns in the central Glückstadt Graben. Along a key geological cross section, the post-Permian strata were sequentially decompacted and restored in order to reconstruct the subsidence history of minibasins between the salt structures. The structural restoration reveals that subsidence of peripheral sinks and salt structure growth were initiated in Early to Middle Triassic time. From the Late Triassic to the Middle Jurassic, salt movement and salt structure growth never ceased, but were faster during periods of crustal extension. Following a phase from Late Jurassic to the end of the early Late Cretaceous, in which minor salt flow occurred, salt movement was renewed, particularly in the marginal parts of the Glückstadt Graben. Subsidence rates and tectonic subsidence derived from backstripping of 1D profiles reveal that especially the Early Triassic and Middle Keuper times were periods of regional extension. Three specific types of salt structures and adjacent peripheral sinks could be identified: (1) Graben centre salt walls possessing deep secondary peripheral sinks on the sides facing away from the basin centre, (2) platform salt walls, whose main peripheral sinks switched multiple times from one side of the salt wall to the other, and (3) Graben edge pillows, which show only one peripheral sink facing the basin centre.

The role of salt tectonics and overburden in the generation of overpressure in the Dutch North Sea area

NARCIS (Netherlands)

Nelskamp, S.; Verweij, J.M.; Witmans, N.

2012-01-01

In this paper we study the effects of timing of salt movement and mechanical compaction on the generation of overpressures in Mesozoic rocks. To that end we apply 2D basin modelling on two N-S trending cross sections in the Dutch Central Graben and Terschelling Basin, respectively. Several

Hydrological Modeling of Highly Glacierized Basins (Andes, Alps, and Central Asia

Directory of Open Access Journals (Sweden)

Nina Omani

2017-02-01

Full Text Available The Soil and Water Assessment Tool (SWAT was used to simulate five glacierized river basins that are global in coverage and vary in climate. The river basins included the Narayani (Nepal, Vakhsh (Central Asia, Rhone (Switzerland, Mendoza (Central Andes, Argentina, and Central Dry Andes (Chile, with a total area of 85,000 km2. A modified SWAT snow algorithm was applied in order to consider spatial variation of associated snowmelt/accumulation by elevation band across each subbasin. In previous studies, melt rates varied as a function of elevation because of an air temperature gradient while the snow parameters were constant throughout the entire basin. A major improvement of the new snow algorithm is the separation of the glaciers from seasonal snow based on their characteristics. Two SWAT snow algorithms were evaluated in simulation of monthly runoff from the glaciered watersheds: (1 the snow parameters are lumped (constant throughout the entire basin and (2 the snow parameters are spatially variable based on elevation bands of a subbasin (modified snow algorithm. Applying the distributed SWAT snow algorithm improved the model performance in simulation of monthly runoff with snow-glacial regime, so that mean RSR decreased to 0.49 from 0.55 and NSE increased to 0.75 from 0.69. Improvement of model performance was negligible in simulations of monthly runoff from the basins with a monsoon runoff regime.

Seismic sequence stratigraphy and platform to basin reservoir structuring of Lower Cretaceous deposits in the Sidi Aïch-Majoura region (Central Tunisia)

Science.gov (United States)

Azaïez, Hajer; Bédir, Mourad; Tanfous, Dorra; Soussi, Mohamed

2007-05-01

In central Tunisia, Lower Cretaceous deposits represent carbonate and sandstone reservoir series that correspond to proven oil fields. The main problems for hydrocarbon exploration of these levels are their basin tectonic configuration and their sequence distribution in addition to the source rock availability. The Central Atlas of Tunisia is characterized by deep seated faults directed northeast-southwest, northwest-southeast and north-south. These faults limit inherited tectonic blocks and show intruded Triassic salt domes. Lower Cretaceous series outcropping in the region along the anticline flanks present platform deposits. The seismic interpretation has followed the Exxon methodologies in the 26th A.A.P.G. Memoir. The defined Lower Cretaceous seismic units were calibrated with petroleum well data and tied to stratigraphic sequences established by outcrop studies. This allows the subsurface identification of subsiding zones and thus sequence deposit distribution. Seismic mapping of these units boundary shows a structuring from a platform to basin blocks zones and helps to understand the hydrocarbon reservoir systems-tract and horizon distribution around these domains.

Macrofaunal diversity in the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Pavithran, S.; Ingole, B.S.; Nanajkar, M.; Nath, B.N.

to the increasing interest of mankind in the non-living resources and destructive deep-sea fishing practices present in these areas. The polymetallic nodule is one such resource, looked upon as an alternative to land-based minerals. The Central Indian Ocean Basin...

Encasement and subsidence of salt minibasins: observations from the SE Precaspian Basin and numerical modeling.

Science.gov (United States)

Fernandez, Naiara; Duffy, Oliver B.; Hudec, Michael R.; Jackson, Christopher A.-L.; Dooley, Tim P.; Jackson, Martin P. A.; Burg, George

2017-04-01

The SE Precaspian Basin is characterized by an assemblage of Upper Permian to Triassic minibasins. A recently acquired borehole-constrained 3D reflection dataset reveals the existence of abundant intrasalt reflection packages lying in between the Permo-Triassic minibasins. We propose that most of the mapped intrasalt reflection packages in the study area are minibasins originally deposited on top of salt that were later incorporated into salt by encasement processes. This makes the SE Precaspian Basin a new example of a salt province populated by encased minibasins, which until now had been mainly described from the Gulf of Mexico. Identifying salt-encased sediment packages in the study area has been crucial, not only because they provide a new exploration target, but also because they can play a key role on improving seismic imaging of adjacent or deeper stratigraphic sections. Another remarkable feature observed in the seismic dataset is the widespread occurrence of distinct seismic sequences in the Permo-Triassic minibasins. Bowl- and wedge-shaped seismic sequences define discrete periods of vertical and asymmetric minibasin subsidence. In the absence of shortening, the bowl-to-wedge transition is typically associated with the timing of basal welding and subsequent rotation of the minibasins. Timing of minibasin welding has important implications when addressing the likelihood of suprasalt reservoir charging. We performed a set of 2D numerical simulations aimed at investigating what drives the tilting of minibasins and how it relates to welding. A key observation from the numerical models is that the bowl-to-wedge transition can predate the time of basal welding.

Monitoring the impact of simulated deep-sea mining in Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.; Nath, B.N.; Jaisankar, S.

Monitoring the Impact of Simulated Deep-sea Mining in Central Indian Basin R. SHARMA, B. NAGENDER NATH, AND S. JAI SANKAR National Institute of Oceanography, Dona Paula, Goa, India Monitoring of deep-sea disturbances, natural or man-made, has gained... has shown a partial recovery of the benthic ecosystem, with indications of restoration and recolonization. Keywords deep-sea mining, environmental impact, Central Indian Basin Deep-sea mineral deposits such as the polymetallic nodules and crusts...

Geologic sources and concentrations of selenium in the West-Central Denver Basin, including the Toll Gate Creek watershed, Aurora, Colorado, 2003-2007

Science.gov (United States)

Paschke, Suzanne S.; Walton-Day, Katherine; Beck, Jennifer A.; Webbers, Ank; Dupree, Jean A.

2014-01-01

concentrations were greatest in samples containing indications of reducing conditions and organic matter (dark gray to black claystones and lignite horizons). The Toll Gate Creek watershed is situated in a unique hydrogeologic setting in the west-central part of the Denver Basin such that weathering of Cretaceous- to Tertiary-aged, non-marine, selenium-bearing rocks releases selenium to groundwater and surface water under present-day semi-arid environmental conditions. The Denver Formation contains several known and suspected geologic sources of selenium including: (1) lignite deposits; (2) tonstein partings; (3) organic-rich bentonite claystones; (4) salts formed as secondary weathering products; and possibly (5) the Cretaceous-Tertiary boundary. Organically complexed selenium and/or selenium-bearing pyrite in the enclosing claystones are likely the primary mineral sources of selenium in the Denver Formation, and correlations between concentration of dissolved selenium and dissolved organic carbon in groundwater indicate weathering and dissolution of organically complexed selenium from organic-rich claystone is a primary process mobilizing selenium. Secondary salts accumulated along fractures and bedding planes in the weathered zone are another potential geologic source of selenium, although their composition was not specifically addressed by the solids analyses. Results from this and previous work indicate that shallow groundwater and streams similarly positioned over Denver Formation claystone units at other locations in the Denver Basin also may contain concentrations of dissolved selenium greater than the Colorado aquatic-life standard or the drinking- water standard.

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.

Generic aspects of salt repositories

International Nuclear Information System (INIS)

Laughon, R.B.

1979-01-01

The history of geological disposal of radioactive wastes in salt is presented from 1957 when a panel of the National Academy of Sciences-National Research Council recommended burial in bedded salt deposits. Early work began in the Kansas, portion of the Permian Basin where simulated wastes were placed in an abandoned salt mine at Lyons, Kansas, in the late 1960's. This project was terminated when the potential effect of nearby solution mining activities could not be resolved. Evaluation of bedded salts resumed a few years later in the Permian Basin in southeastern New Mexico, and search for suitable sites in the 1970's resulted in the formation of the National Waste Terminal Storage Program in 1976. Evaluation of salt deposits in many regions of the United States has been virtually completed and has shown that deposits having the greatest potential for radioactive waste disposal are those of the largest depositional basins and salt domes of the Gulf Coast region

Chemical stratigraphy of Grande Ronde Basalt, Pasco Basin, south-central Washington

International Nuclear Information System (INIS)

Long, P.E.; Ledgerwood, R.K.; Myers, C.W.; Reidel, S.P.; Landon, R.D.; Hooper, P.R.

1980-02-01

Grande Ronde Basalt in the Pasco Basin, south-central Washington, can be subdivided into three chemical types and two chemical subtypes based on x-ray fluorescence major element analysis of samples from seven deep core holes and three surface sections. These chemical types are: (1) high-Mg Grande Ronde chemical type; (2) low-Mg Grande Ronde chemical type; (3) low-K (very high-Mg.) Grande Ronde chemical type; and (4) Umtanum Grande Ronde chemical subtype. A possible fifth subdivision is the McCoy Canyon Grande Ronde chemical subtype. The Umtanum and the McCoy Canyon subtypes are both single flows which belong to the low Mg and high-Mg chemical types, respectively. These subdivisions are all distinguished on a plot of MgO versus TiO 2 and/or MgO versus P 2 O 5 , but other major and minor elements, as well as trace elements, also reflect consistent chemical differences between the chemical types. Identification of these chemical types in the Pasco Basin subsurface shows that the high-Mg and low-Mg chemical types are ubiquitous, but the low-K chemical type is limited to the central, southern, and eastern parts of the basin. The Umtanum chemical subtype is present throughout the Pasco Basin subsurface, although it thins in the northeastern part of the basin and is apparently absent from surface exposures 40 kilometers (25 miles) north of the basin. The McCoy Canyon chemical subtype is also present throughout the basin

Late quaternary geomorphology of the Great Salt Lake region, Utah, and other hydrographically closed basins in the western United States: A summary of observations

Science.gov (United States)

Currey, Donald R.

1989-01-01

Attributes of Quaternary lakes and lake basins which are often important in the environmental prehistory of semideserts are discussed. Basin-floor and basin-closure morphometry have set limits on paleolake sizes; lake morphometry and basin drainage patterns have influenced lacustrine processes; and water and sediment loads have influenced basin neotectonics. Information regarding inundated, runoff-producing, and extra-basin spatial domains is acquired directly from the paleolake record, including the littoral morphostratigraphic record, and indirectly by reconstruction. Increasingly detailed hypotheses regarding Lake Bonneville, the largest late Pleistocene paleolake in the Great Basin, are subjects for further testing and refinement. Oscillating transgression of Lake Bonneville began about 28,000 yr B.P.; the highest stage occurred about 15,000 yr B.P., and termination occurred abruptly about 13,000 yr B.P. A final resurgence of perennial lakes probably occurred in many subbasins of the Great Basin between 11,000 and 10,000 yr B.P., when the highest stage of Great Salt Lake (successor to Lake Bonneville) developed the Gilbert shoreline. The highest post-Gilbert stage of Great Salt Lake, which has been one of the few permanent lakes in the Great Basin during Holocene time, probably occurred between 3,000 and 2,000 yr B.P.

Paleothermicity in the Central Asturian Coal Basin, North Spain

Energy Technology Data Exchange (ETDEWEB)

Piedad-Sanchez, Noe; Izart, Alain; Martinez, Luis; Elie, Marcel; Menetrier, Cedric [UMR G2R/7566-Geologie et Gestion des Ressources Minerales et Energetiques, Equipe Dynamique des Bassins Sedimentaires et des Matieres Organiques, Faculte des Sciences, Universite Henri Poincare, Nancy 1, BP-239, Boulevard des Aiguillettes, 54506 Vandoeuvre-les-Nancy Cedex (France); Suarez-Ruiz, Isabel [Instituto Nacional del Carbon (CSIC), C/ Francisco Pintado Fe, 26, 33011-Oviedo (Spain)

2004-06-23

This research shows for the first time maps of vitrinite reflectances and paleotemperatures from the Central Asturian Coal Basin (North Spain) which is a Carboniferous (Pennsylvanian) Basin mainly of Moscovian age. Vitrinite reflectance values decrease from north to south whereas volatile matter distribution increases from south to north. Vitrinite reflectance and volatile matter parameters indicate a coal rank ranging from high volatile bituminous coal in the north, to semianthracite and anthracite in the south. Rock-Eval data show that the organic matter of this basin is Type III kerogen, with a maturation ranging from oil to gas window. Paleotemperatures were calculated by diverse methods using vitrinite reflectance data for different durations of heating and Rock-Eval results. The calculated paleotemperatures and vertical paleotemperature gradients decrease from south to north. The thermal gradient variation in the Central Asturian Coal Basin points to the influence of at least two heating events that affected the organic matter. The first associated with a regular geothermal gradient operating over a long period of time, and the second linked to a southern granitic event of short duration estimated by tectonic data. The short thermal event was located at the end of sedimentation (Late Moscovian and Late Westphalian D) and after folding, but before the overthrusting during the Asturian tectonic phase located before the Early Kasimovian (Cantabrian and Stephanian) deposits. Finally, a simulation of paleotemperatures around the granitic pluton was calculated and compared to maps of paleotemperatures obtained by various methods. These maps refer to an initial depth of one or two km in accordance with the selected methods that are compatible with local erosion. This approach was preferred in order to explain the metamorphism of coal, rather than the hypothesis of hydrothermal fluid flow proposed for other foreland basins. This regional thermal anomaly could be

Spatial distribution and longitudinal variation of clay minerals in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Valsangkar, A.

in the Central Indian Basin (CIB). The average sand content in the basin is 3.8%, which decreases systematically and longitudinally to 0.3% towards south. The average illite and chlorite major clay mineral abundance also decrease southwards along the four...

Drift pumice in the central Indian Ocean Basin: Geochemical evidence

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Mudholkar, A.V.; JaiSankar, S.; Ilangovan, D.

Abundant white to light grey-coloured pumice without ferromanganese oxide coating occurs within the Quaternary sediments of the Central Indian Ocean Basin (CIOB). Two distinct groups of pumice are identified from their geochemical composition, which...

Salt dissolution in oil and gas test holes in central Kansas. Part I. Salt beds in the subsurface in Russell, Lincoln, Ellsworth, Barton, and Rice Counties, central Kansas

International Nuclear Information System (INIS)

Walters, R.F.

1975-06-01

The Hutchinson Salt Member of the Permian Wellington Formation is described in a five-county study area of 4,000 square miles. Most of the 22,200 oil and gas test holes in the study area were drilled with fresh water, causing dissolution of the salt during drilling, commonly resulting in borehole enlargement to three times the diameter of the drill bit (some older rotary drilled holes have borehole enlargement up to 10 ft). After drilling ceases, no salt dissolution occurs in oil and gas test holes which have properly cemented surface casing protecting all aquifers above the salt. The conclusion is reached that extensive dissolution of the Hutchinson Salt in oil and gas test holes in central Kansas is a rare and unusual event in the 50-year history since the discovery of oil in Russell County in 1923. In only seven known instances (six of which are within the study area) did such dissolution lead to collapse and surface subsidence. With an estimated 72,000 holes drilled through the Hutchinson Salt Member within the State of Kansas, this is a ratio of approximately one occurrence for every 10,000 oil and gas test holes

Aptian ‘Shale Gas’ Prospectivity in the Downdip Mississippi Interior Salt Basin, Gulf Coast, USA

Science.gov (United States)

Hackley, Paul C.; Valentine, Brett J.; Enomoto, Catherine B.; Lohr, Celeste D.; Scott, Krystina R.; Dulong, Frank T.; Bove, Alana M.

2016-01-01

This study evaluates regional ‘shale gas’ prospectivity of the Aptian section (primarily Pine Island Shale) in the downdip Mississippi Salt Basin (MSB). Previous work by the U.S. Geological Survey estimated a mean undiscovered gas resource of 8.8 trillion cubic feet (TCF) in the chronostratigraphic-equivalent Pearsall Formation in the Maverick Basin of south Texas, where industry has established a moderately successful horizontal gas and liquids play. Wells penetrating the downdip MSB Aptian section at depths of 12,000-15,000 ft were used to correlate formation tops in a 15-well cross-section extending about 200 miles (mi) east-southeastward from Adams Co. to Jackson Co. Legacy cuttings from these wells were analyzed for thermal maturity and source rock quality. Bitumen reflectance (n=53) increases with increasing present-day burial depth in the east-central study area from 1.0% to 1.7%. As the Aptian section shallows in Adams Co. to the west, bitumen Ro values are higher (1.7-2.0%), either from relatively greater heat flux or greater mid-Cenomanian uplift and erosion in this area. Total organic carbon (TOC) content ranges 0.01-1.21 and averages 0.5 wt.% (n=51); pyrolysis output (S2; n=51) averages 0.40 mg HC/g rock, indicating little present-day hydrocarbon-generative potential. Bitumen reflectance is preferred as a thermal maturity parameter as Tmax values are unreliable. Normalized X-ray diffraction (XRD) mineral analyses (n=26) indicate high average clay abundance (53 wt.%) relative to quartz (29%) and carbonate (18%). Mineral content shows a spatial relationship to an Appalachian orogen clastic sediment source, with proximal high clay and quartz and distal high carbonate content. Clastic influx from the Appalachian orogen is confirmed by detrital zircon U-Pb ages with dominant Grenville and Paleozoic components [105 ages from a Rodessa sandstone and 112 ages from a Paluxy (Albian) sandstone]. Preliminary information from fluid inclusion microthermometry

A note on incipient spilitisation of central Indian basin basalts

Digital Repository Service at National Institute of Oceanography (India)

Karisiddaiah, S.M.; Iyer, S.D.

Rocks dredged in the vicinity of the 79 degrees E fracture zone, in the Central Indian Basin, are sub-alkaline basalts, which are regarded as precursors to spilites. The minerals identified are mainly albitic plagioclase, augite, olivine, and less...

Paleobasin analysis and tectonic framework development of southern Zagros basin, interpreted from Landsat 4 thematic mapper image

Energy Technology Data Exchange (ETDEWEB)

Iranpanah, A.

1986-05-01

Detailed lineament maps produced with the digitally enhanced Landsat 4 thematic mapper in conjunction with field data provide new information on structural relations to the southern Zagros basin. Three major parallel lineaments are from north to south, Qatar-Kazern, Razak, and Oman. These lineaments trend approximately N17/sup 0/E and subdivide the Zagros basin into northern, central, and southern segments. The study area is enclosed by the Razak and Oman lineaments. Piercement salt domes (Precambrian salt) are abundant within the southern Zagros basin, absent east of the Oman lineament, and scarce in the area west of the Razak lineament. This salt dome distribution and the N17/sup 0/E trend suggest that these lineaments are surface manifestations of boundaries of basement crustal blocks that have been reactivated periodically since the Precambrian. The northern extension of this Precambrian basin is marked by salt domes (Precambrian salt) along the Oman lineament, located in the Kerman region 400 km north of Minab. Along the eastern boundary, at the juncture of the southern Zagros basin and western Makran Ranges, the trend of fold axes changes from east-west to north-south. The western basin boundary is characterized by a gradual change in the trend of the fold axis from east-west to northwest-southeast. This study provides useful information for subsurface interpretations, which will benefit hydrocarbon exploration. The Razak and Oman lineaments enclose a highly productive area, and separate the southern Zagros basin from less productive areas to the west and from a nonproductive region to the east where chromite and iron deposits are common. These findings suggest that lineaments may serve as an exploration guide for hydrocarbons and economic mineral deposits, and as a model for developing the tectonic framework of the southern Zagros basin.

GEOMORPHIC CONTROLS ON MEADOW ECOSYSTEMS IN THE CENTRAL GREAT BASIN

Science.gov (United States)

Wet meadows, riparian corridor phreatophyte assemblages, and high-altitude spring-fed aspen meadows comprise a very small percentage of the total landscape of the mountain ranges in the central Great Basin however, they represent important ecological environments. We have used s...

FIRST RECORD OF Alburnusatropatenae (BERG,1925) (CYPRINIDAE) IN NAMAK BASIN, CENTRAL IRAN

OpenAIRE

Khataminejad, Somaye; Mousavi-Sabet, Hamed; Sattari, Masud; Vatandoust, Saber

2013-01-01

AlburnusatropatenaeBerg, 1925 is reported for the first time from the River Ghareh-Chay in the Namak basin, central Iran. Previously, this species has onlybeen reported from the LakeOrumiyeh basin, in northwest Iran. In this report twenty-nine specimens were caught on 8 August 2012. Morphometric and meristic characteristics of the specimens were similar to those reported elsewhere for the species.

Water-quality data for aquifers, streams, and lakes in the vicinity of Keechi, Mount Sylvan, Oakwood, and Palestine salt domes, northeast Texas salt-dome basin

International Nuclear Information System (INIS)

Carr, J.E.; Halasz, S.J.; Liscum, F.

1980-11-01

This report contains water-quality data for aquifers, streams, and lakes in the vicinity of Keechi, Mount Sylvan, Oakwood, and Palestine Salt Domes in the northeast Texas salt-dome basin. Water-quality data were compiled for aquifers in the Wilcox Group, the Carrizo Sand, and the Queen City Sand. The data include analyses for dissolved solids, pH, temperature, hardness, calcium, magnesium, sodium, bicarbonate, chloride, and sulfate. Water-quality and streamflow data were obtained from 63 surface-water sites in the vicinity of the domes. These data include water discharge, specific conductance, pH, water temperature, and dissolved oxygen. Samples were collected at selected sites for analysis of principal and selected minor dissolved constituents

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...

Ferromanganese oxides on sharks' teeth from Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Iyer, S.D.

The mineralogy, composition and growth rates of ferromanganese (Fe-Mn) oxides over the sharks' teeth from the Central Indian Ocean Basin are presented. The trends of metal enrichment (Mn, Ni, Cu and Zn) and depletion (Fe and Co), the Mn/Fe ratio...

Fibers and cylinders of cryptomelane-hollandite in Permian bedded salt, Palo Duro Basin, Texas

International Nuclear Information System (INIS)

Belkin, H.E.; Libelo, E.L.

1987-01-01

Fibers and thin-walled, hollow cylinders of cryptomelane-hollandite have been found in both the chevron and the clear salt from various drill cores in Permian bedded salt from the Palo Duro Basin, Texas. The authors have found fibers or cylinders from only the lower San Andres Formation units 4 and 5, the upper San Andres Formation, and the Salado-Transill salt. The fibers are inorganic, light to dark reddish brown, pleochroic, highly birefringent, filamentary single crystals, < 1 to ∼ 5 μm in diameter, with length-to-diameter ratios of at least 20:1. The fibers can be straight and/or curved, can bifurcate, can form loops, waves or spirals, and can be isolated or in parallel groups. Detailed petrographic analyses show no evidence for recrystallization or deformation of the enclosing salt after fiber formation. Although the authors observations do not provide a definitive explanation for fiber origin, they suggest that the fibers grew in situ by a solid-state diffusional process at low temperatures. The cylinders are pleochroic, highly birefringent, light to dark reddish brown, hollow, thin-walled, open-ended right cylinders, having a 1- to 2-μm wall thickness and variable lengths and diameters. There also appear to be single crystals of cryptomelane-hollandite, but these are found almost entirely in fluid inclusions in the chevron and clear salt. Their presence in the primary halite suggests that they were formed contemporaneously with the chevron structure and were accidentally trapped in the fluid inclusions. The observation of cylinders partially or completely enclosed by salt stratigraphically above large fluid inclusions suggests that natural downward fluid-inclusion migration has occurred, in response to the geothermal gradient

Oligocene Fluvio-Deltaic Depositional Environments Salin Sub-Basin, Central Myanmar

Science.gov (United States)

Gough, A.; Hall, R.

2017-12-01

A recent increase in accessibility for research in Myanmar has allowed rapid advancements in the understanding of the geology of the country. Evolving depositional environments can be reconstructed in largely unstudied Oligocene deposits of the Salin sub-basin, of the Central Myanmar Basin. Data has been collected through a fieldwork campaign to target well-exposed sediments along the western margin of the basin. The studied outcrops span approximately one hundred kilometres from north to south, and a series of sedimentary logs, palaeocurrent data, 2D panel diagrams, and samples for petrographical analysis have been collected and interpreted. The Oligocene formations studied include the Shwezetaw, Paduang, and Okhmintaung, each of which show a broadly southwards-trending fluvio-deltaic environment of deposition. Towards the north, the lower Rupelian Shwezetaw Formation comprises thick fluviatile sandstones which grade southwards through macrotidal-dominated fluvio-deltaic interbedded siltstones and rare sandstones, into marine sandstones. Overlying this, the upper Rupelian Paduang Formation grades rapidly from rare fluvial sandstones towards the north of the basin into deltaic and marine interbedded sandstones and siltstones to the south. This formation is more marine in nature, suggesting a minor transgression throughout the lower Oligocene. By the time of deposition of the Okhmintaung Formation in the Chattian the observed deposits solely represent a tidally-influenced deltaic depositional environment, with very little temporal variation, suggesting a stable sea level. Despite the relatively unchanging depositional environment, the formations are approximately 4000 m thick, suggesting that sedimentation kept pace with relatively rapid subsidence. This current study, which will combine depositional environment reconstruction, provenance, and sediment routing analysis, will provide important insights into both the tectonic setting and the huge sediment accumulation

Assessing and addressing the re-eutrophication of Lake Erie: central basin hypoxia

Science.gov (United States)

Scavia, Donald; Allan, J. David; Arend, Kristin K.; Bartell, Steven; Beletsky, Dmitry; Bosch, Nate S.; Brandt, Stephen B.; Briland, Ruth D.; Daloğlu, Irem; DePinto, Joseph V.; Dolan, David M.; Evans, Mary Anne; Farmer, Troy M.; Goto, Daisuke; Han, Haejin; Höök, Tomas O.; Knight, Roger; Ludsin, Stuart A.; Mason, Doran; Michalak, Anna M.; Richards, R. Peter; Roberts, James J.; Rucinski, Daniel K.; Rutherford, Edward; Schwab, David J.; Sesterhenn, Timothy M.; Zhang, Hongyan; Zhou, Yuntao

2014-01-01

Relieving phosphorus loading is a key management tool for controlling Lake Erie eutrophication. During the 1960s and 1970s, increased phosphorus inputs degraded water quality and reduced central basin hypolimnetic oxygen levels which, in turn, eliminated thermal habitat vital to cold-water organisms and contributed to the extirpation of important benthic macroinvertebrate prey species for fishes. In response to load reductions initiated in 1972, Lake Erie responded quickly with reduced water-column phosphorus concentrations, phytoplankton biomass, and bottom-water hypoxia (dissolved oxygen 2) requires cutting total phosphorus loads by 46% from the 2003–2011 average or reducing dissolved reactive phosphorus loads by 78% from the 2005–2011 average. Reductions to these levels are also protective of fish habitat. We provide potential approaches for achieving those new loading targets, and suggest that recent load reduction recommendations focused on western basin cyanobacteria blooms may not be sufficient to reduce central basin hypoxia to 2000 km2.

Biological characteristics of Central Indian Basin waters during the southern summer

Digital Repository Service at National Institute of Oceanography (India)

Matondkar, S.G.P.; Nair, K.K.C.; Ansari, Z.A.

Phytoplankton biomass, taxonomy, primary productivity, and photosynthetically available radiation (PAR) were studied as part of baseline data collection for prospective nodule mining in the Central Indian Basin during the ORV Sagar Kanya cruise SK...

Petrographical indicators of petrogenesis: Examples from Central Indian Ocean Basin basalts

Digital Repository Service at National Institute of Oceanography (India)

Mislankar, P.G.; Iyer, S.D.

Petrographical features of the Central Indian Basin (CIOB) basalts were studied to understand their genetic significance. The fresh basaltic pillows show three textural zones from the top glassy (zone A) through the intermediate (zone B...

Observed Hydrologic Impacts of Landfalling Atmospheric Rivers in the Salt and Verde River Basins of Arizona, United States

Science.gov (United States)

Demaria, Eleonora M. C.; Dominguez, Francina; Hu, Huancui; von Glinski, Gerd; Robles, Marcos; Skindlov, Jonathan; Walter, James

2017-12-01

Atmospheric rivers (ARs), narrow atmospheric water vapor corridors, can contribute substantially to winter precipitation in the semiarid Southwest U.S., where natural ecosystems and humans compete for over-allocated water resources. We investigate the hydrologic impacts of 122 ARs that occurred in the Salt and Verde river basins in northeastern Arizona during the cold seasons from 1979 to 2009. We focus on the relationship between precipitation, snow water equivalent (SWE), soil moisture, and extreme flooding. During the cold season (October through March) ARs contribute an average of 25%/29% of total seasonal precipitation for the Salt/Verde river basins, respectively. However, they contribute disproportionately to total heavy precipitation and account for 64%/72% of extreme total daily precipitation (exceeding the 98th percentile). Excess precipitation during AR occurrences contributes to snow accumulation; on the other hand, warmer than normal temperatures during AR landfallings are linked to rain-on-snow processes, an increase in the basins' area contributing to runoff generation, and higher melting lines. Although not all AR events are linked to extreme flooding in the basins, they do account for larger runoff coefficients. On average, ARs generate 43% of the annual maximum flows for the period studied, with 25% of the events exceeding the 10 year return period. Our analysis shows that the devastating 1993 flooding event in the region was caused by AR events. These results illustrate the importance of AR activity on the hydrology of inland semiarid regions: ARs are critical for water resources, but they can also lead to extreme flooding that affects infrastructure and human activities.

Benthic disturbance and impact experiments in the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.; Nath, B.N.; Valsangkar, A.B.; Parthiban, G.; Sivakholundu, K.M.; Walker, G.A.

As a part of the Environmental Impact Assessment studies for nodule mining, a long-term program has been initiated in the Central Indian Basin. Multidisciplinary studies on geological, biological, physical and chemical parameters were carried out...

Geology, selected geophysics, and hydrogeology of the White River and parts of the Great Salt Lake Desert regional groundwater flow systems, Utah and Nevada

Science.gov (United States)

Rowley, Peter D.; Dixon, Gary L.; Watrus , James M.; Burns, Andrews G.; Mankinen, Edward A.; McKee, Edwin H.; Pari, Keith T.; Ekren, E. Bartlett; Patrick , William G.; Comer, John B.; Inkenbrandt, Paul C.; Krahulec, K.A.; Pinnell, Michael L.

2016-01-01

The east-central Great Basin near the Utah-Nevada border contains two great groundwater flow systems. The first, the White River regional groundwater flow system, consists of a string of hydraulically connected hydrographic basins in Nevada spanning about 270 miles from north to south. The northernmost basin is Long Valley and the southernmost basin is the Black Mountain area, a valley bordering the Colorado River. The general regional groundwater flow direction is north to south. The second flow system, the Great Salt Lake Desert regional groundwater flow system, consists of hydrographic basins that straddle

Uranium in selected endorheic basins as partial analogue for spent fuel behavior in salt

International Nuclear Information System (INIS)

Van Luik, A.E.

1987-01-01

If uranium (U) behavior with respect to the components of certain endorheic (closed) basin subsurface, playa, or terminal lake brines were quantitatively understood, the ability to predict the long-term redistribution of emplaced U among analogous components of salt formations may be enhanced. Tests that determine the nature of U interactions with pure mineral and organic matter surfaces are important, but studying the natural systems available could give indications of long-term stabilities of processes, and of preferential processes. For example, some metals present in trace quantities, such as U, may be coprecipitated in the oxidized zone with an evaporite mineral that may afterward undergo diagenesis, especially if conditions become more reducing. During diagenesis, the trace metal may be remobilized, but scavenged by sulfides or organic particulates, leaving the evaporite mineral depleted of its trace metal content. A survey of the literature shows trace metal behavior in closed basins has been studied. However, information on U consists of only a few abundance determinations for some evaporite systems. Obtaining and interpreting natural analogue data for the U and Th decay series in selected endorheic basin environments is suggested. 44 refs., 3 figs

Uranium in selected endorheic basins as partial analogue for spent fuel behavior in salt

International Nuclear Information System (INIS)

Luik, A.E. van

1987-01-01

If uranium (U) behavior with respect to the components of certain endorheic (closed) basin subsurface, playa, or terminal lake brines were quantitatively understood, the ability to predict the long-term redistribution of emplaced U among analogous components of salt formations may be enhanced. Tests that determine the nature of U interactions with pure mineral and organic matter surfaces are important, but studying the natural systems available could give indications of long-term stabilities of processes, and of preferential processes. For example, some metals present in trace quantities, such as U, may be coprecipitated in the oxidized zone with an evaporite mineral that may afterwards undergo diagenesis, especially if conditions become more reducing. During diagenesis, the trace metal may be remobilized, but scavenged by sulfides or organic particulates, leaving the evaporite mineral depleted of its trace metal content. A survey of the literature shows some trace metal behavior in closed basins has been studied. However, information on U consists of only a few abundance determinations for some evaporite systems. Obtaining and interpreting natural analogue data for the U and Th decay series in selected endorheic basin environments is suggested. (author)

Chapter 7. The GIS project for the geologic assessment of undiscovered oil and gas in the Cotton Valley group and Travis Peak and Hosston formations, East Texas basin and Louisiana-Mississippi salt basins provinces.

Science.gov (United States)

Biewick, Laura

2006-01-01

A geographic information system (GIS) focusing on the Upper Jurassic-Lower Cretaceous Cotton Valley Group and the Lower Cretaceous Travis Peak and Hosston Formations in the northern Gulf Coast region was developed as a visual-analysis tool for the U.S. Geological Survey's 2002 assessment of undiscovered, technically recoverable oil and natural gas resources in the East Texas Basin and Louisiana-Mississippi Salt Basins Provinces. The Central Energy Resources Team of the U.S. Geological Survey has also developed an Internet Map Service to deliver the GIS data to the public. This mapping tool utilizes information from a database about the oil and natural gas endowment of the United States-including physical locations of geologic and geographic data-and converts the data into visual layers. Portrayal and analysis of geologic features on an interactive map provide an excellent tool for understanding domestic oil and gas resources for strategic planning, formulating economic and energy policies, evaluating lands under the purview of the Federal Government, and developing sound environmental policies. Assessment results can be viewed and analyzed or downloaded from the internet web site, http://energy.cr.usgs.gov/oilgas/noga/ .

Benthic disturbance and monitoring experiment in the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.; Nath, B.N.

Environmental impact assessment studies for deep-sea manganese nodule mining have been initiated in the Central indian Ocean Basin since 1995. As a part of the first phase for collecting the benthic baseline data, echosounding, subbottom profiling...

Physical properties of a sediment core from the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Khadge, N.H.

A box core of 7.5 m was collected from the Central Indian Basin for the purpose of geotechnical studies and depthwise variation of physical properties and clay mineralogy. Water content, Atterberg limits, specific gravity are measured at regular...

Geologic framework and petroleum systems of Cook Inlet basin, south-central Alaska

Science.gov (United States)

LePain, D.L.; Stanley, R.G.; Helmold, K.P.; Shellenbaum, D.P.; Stone, D.M.; Hite, D.M.

2013-01-01

This report provides a comprehensive overview of the stratigraphy, structure, tectonics, and petroleum systems of the Cook Inlet basin, an important oil- and gas-producing region in south-central Alaska.

Some aspects of volcanic ash layers in the Central Indian Basin.

Digital Repository Service at National Institute of Oceanography (India)

Sukumaran, N.P.; Banerjee, R.; Borole, D.V.; Gupta, S.M.

Intercalated volcanic ash layers in two deep-sea sediment cores from the Central Indian Basin (CIB) are examined for the possibility of an in situ source of suboceanic volcanism. An in situ source has been predicated based on the bottom...

Distribution and origin of seamounts in the central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Das, P.; Iyer, S.D.; Kodagali, V.N.; Krishna, K.S.

Approximately 200 seamounts of different dimensions have been identified, from multibeam bathymetry maps of the Central Indian Ocean Basin (CIOB) (9 degrees S to 16 degrees S and 72 degrees E to 80 degrees E), of which 61% form eight chains...

Ore grade manganese nodules from the central Indian basin: an evaluation

Digital Repository Service at National Institute of Oceanography (India)

Sudhakar, M.

Comparative studies on manganese nodules from two different areas (S and R) in the Central Indian Basin show distinct variations in their composition, grade (percent Ni + Cu), and abundance (kg/m2), which are explained in terms of various genetic...

Preliminary geotechnical properties of deepsea sediments from the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Khadge, N.H.

Geotechnical properties of the Plio-Pleistocene sediments from nodule bearing area in the Central Indian Basin have been studied to know shear strength and water content variation with depth. It reveals that surface sediments have low (less than 1 k...

Constitutive parameters for salt and nonsalt rocks from the Detten, G. Friemel, and Zeeck wells in the Palo Duro Basin, Texas

International Nuclear Information System (INIS)

Senseny, P.E.; Pfeifle, T.W.; Mellegard, K.D.

1985-01-01

Results are presented from laboratory tests performed on salt and nonsalt rocks from the Palo Duro Basin in Texas. The Unit 5 salt from the Lower San Andres is assumed to be the repository horizon and is more completely characterized than other strata. For the Unit 5 salt, values are given for the parameters in the exponential-time constitutive law that models the time-independent elastic deformation and the time-dependent inelastic deformation. Both linear and nonlinear failure envelopes for this salt at 20 0 C are also determined. Data reported for twenty other salt and nonsalt horizons include tangent moduli and principal strain ratios, as well as linear failure envelopes at 20 0 C. The matrix of tests performed is adequate for conceptual repository design and performance analysis. However, final repository design and performance analysis requires more extensive characterization of the constitutive behavior of the stratigraphy, especially the repository-horizon salt

Pre-Messinian (Sub-Salt Source-Rock Potential on Back-Stop Basins of the Hellenic Trench System (Messara Basin, Central Crete, Greece

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Maravelis A.

2016-01-01

Full Text Available The Greek part of the Mediterranean Ridge suggests, in terms of its hydrocarbon potential, further frontier exploration. The geological similarities between its prolific portions, within the Cyprus and Egyptian Exclusive Economic Zones, indicate possible recoverable natural gas reserves in its Greek portion. Nevertheless it lacks of systematic frontier exploration although direct petroleum indicators occur. Active mud volcanoes on the Mediterranean Ridge, still emitting concurrently gas and gas hydrates, have not been yet assessed even though are strongly related to hydrocarbon occurrence worldwide (Caspian Sea, Gulf of Mexico, Western African Basin, Trinidad-Tobago, the Nile Cone. For this reason, the source rock potential of the Late Miocene lacustrine deposits on a backstop basin of the Hellenic Trench System (Messara Basin, Crete, Greece, was studied. The obtained pyrolysis data indicate that the containing organic matter is present in sufficient abundance and with good enough quality to be regarded as potential source rocks. The observed type III kerogen suggests gas generation potential. Although indications of higher thermal evolution occur the studied rocks suggest low maturation levels. The biogenic gas seeps in the studied research well further demonstrate the regional gas generation potential.

Sedimentary Record of the Back-Arc Basins of South-Central Mexico: an Evolution from Extensional Basin to Carbonate Platform.

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Sierra-Rojas, M. I.; Molina-Garza, R. S.; Lawton, T. F.

2015-12-01

The Lower Cretaceous depositional systems of southwestern Oaxaquia, in south-central Mexico, were controlled by tectonic processes related to the instauration of a continental arc and the accretion of the Guerrero arc to mainland Mexico. The Atzompa Formation refers to a succession of conglomerate, sandstone, siltstone, and limestone that crop out in southwestern Mexico with Early Cretaceous fauna and detrital zircon maximum depositional ages. The sedimentary record shows a transition from early fluvial/alluvial to shallow marine depositional environments. The first stage corresponds to juvenile fluvial/alluvial setting followed by a deep lacustrine depositional environment, suggesting the early stages of an extensional basin. The second stage is characterized by anabranched deposits of axial fluvial systems flowing to the NE-SE, showing deposition during a period of rapid subsidence. The third and final stage is made of tidal deposits followed, in turn, by abrupt marine flooding of the basin and development of a Barremian-Aptian carbonate ramp. We interpret the Tentzo basin as a response to crustal extension in a back-arc setting, with high rates of sedimentation in the early stages of the basin (3-4 mm/m.y), slower rates during the development of starved fluvial to tidal systems and carbonate ramps, and at the top of the Atzompa Formation an abrupt deepening of the basin due to flexural subsidence related to terrane docking and attendant thrusting to the west. These events were recorded in the back-arc region of a continental convergent margin (Zicapa arc) where syn-sedimentary magmatism is indicated by Early Cretaceous detrital and volcanic clasts from alluvial fan facies west of the basin. Finally, and as a response to the accretion of the Guerrero superterrane to Oaxaquia during the Aptian, a carbonate platform facing toward the Gulf of Mexico was established in central to eastern Oaxaquia.

Hydrocarbon potential of a new Jurassic play, central Tunisia

International Nuclear Information System (INIS)

Beall, A.O.; Law, C.W.

1996-01-01

A largely unrecognized Jurassic Sag Basin has been identified in central Tunisia, proximal to the Permo-Carboniferous flexure delineating the northern boundary of the Saharan platform of north Africa. The northwestern margin of the Sag is delineated by an extensive region of salt-cored anticlines and localized salt diapirs extending north and west. Due to lack of deep drilling, delineation of the Sag is largely based on regional gravity data. Subsidence of the Jurassic Sag Basin is characterized by rapid expansion of Jurassic sediments from 400 m. of tidal flat and shelf carbonate at the western outcrop to over 2000 meters of tidal flat and basinal carbonate and shale within the basin center, a five-fold expansion. Rapid loading of the basin continued into Lower Cretaceous time, marked by lateral flowage of Triassic salt into pronounced structural trends. Published source rock data and interpreted subsurface well data provided the basis for GENEX 1-D hydrocarbon generation and expulsion modeling of the Sag. Middle Jurassic black source shales typically contain Type II and Type III kerogens with T.O.C.'s ranging up to 4 percent. Modeling results indicate that middle Jurassic shales are presently mature for liquid generation within portions of the Sag, with maximum generation taking place during the Tertiary. Potential hydrocarbon generation yields, based on 60 meters of mature source shale, are 20,000 BOE/acre for gas and 75,000 BOE/acre for liquids. Prospects within the region could contain an estimated potential reserve of several T.C.F. or over 1 billion barrels of oil

FIRST RECORD OF Alburnus atropatenae (BERG, 1925 (CYPRINIDAE IN NAMAK BASIN, CENTRAL IRAN

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Somaye Khataminejad

2013-01-01

Full Text Available Alburnus atropatenae Berg, 1925 is reported for the first time from the River Ghareh-Chay in the Namak basin, central Iran. Previously, this species has only been reported from the Lake Orumiyeh basin, in northwest Iran. In this report twenty-nine specimens were caught on 8 August 2012. Morphometric and meristic characteristics of the specimens were similar to those reported elsewhere for the species.

FIRST RECORD OF Alburnus atropatenae (BERG, 1925) (CYPRINIDAE) IN NAMAK BASIN, CENTRAL IRAN

OpenAIRE

Somaye Khataminejad; Hamed Mousavi-Sabet; Masud Sattari; Saber Vatandoust

2013-01-01

Alburnus atropatenae Berg, 1925 is reported for the first time from the River Ghareh-Chay in the Namak basin, central Iran. Previously, this species has only been reported from the Lake Orumiyeh basin, in northwest Iran. In this report twenty-nine specimens were caught on 8 August 2012. Morphometric and meristic characteristics of the specimens were similar to those reported elsewhere for the species.

The nitrogen budget for different forest types in the central Congo Basin

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Bauters, Marijn; Verbeeck, Hans; Cizungu, Landry; Boeckx, Pascal

2016-04-01

Characterization of fundamental processes in different forest types is vital to understand the interaction of forests with their changing environment. Recent data analyses, as well as modeling activities have shown that the CO2 uptake by terrestrial ecosystems strongly depends on site fertility, i.e. nutrient availability. Accurate projections of future net forest growth and terrestrial CO2 uptake thus necessitate an improved understanding on nutrient cycles and how these are coupled to the carbon (C) cycle in forests. This holds especially for tropical forests, since they represent about 40-50% of the total carbon that is stored in terrestrial vegetation, with the Amazon basin and the Congo basin being the largest two contiguous blocks. However, due to political instability and reduced accessibility in the central Africa region, there is a strong bias in scientific research towards the Amazon basin. Consequently, central African forests are poorly characterized and their role in global change interactions shows distinct knowledge gaps, which is important bottleneck for all efforts to further optimize Earth system models explicitly including this region. Research in the Congo Basin region should combine assessments of both carbon stocks and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for carbon stocks and nitrogen fluxes in four different forest types in the Congo Basin, which is now operative. With the preliminary data, we can get a glimpse of the differences in nitrogen budget and biogeochemistry of African mixed lowland rainforest, monodominant lowland forest, mixed montane forest and eucalypt plantations.

Waterbird habitat in California's Central Valley basins under climate, urbanization, and water management scenarios

Science.gov (United States)

Matchett, Elliott L.; Fleskes, Joseph

2018-01-01

California's Central Valley provides critical, but threatened habitat and food resources for migrating and wintering waterfowl, shorebirds, and other waterbirds. The Central Valley is comprised of nine basins that were defined by the Central Valley Joint Venture (CVJV) to assist in conservation planning. Basins vary in composition and extent of habitats, which primarily include croplands and wetlands that rely on water supplies shared with other competing human and environmental uses. Changes in climate, urban development, and water supply management are uncertain and could reduce future availability of water supplies supporting waterbird habitats and limit effectiveness of wetland restoration planned by the CVJV to support wintering waterbirds. We modeled 17 plausible scenarios including combinations of three climate projections, three urbanization rates, and five water supply management options to promote agricultural and urban water uses, with and without wetland restoration. Our research examines the reduction in quantity and quality of habitats during the fall migration-wintering period by basin under each scenario, and the efficacy of planned wetland restoration to compensate reductions in flooded areas of wetland habitats. Scenario combinations of projected climate, urbanization, and water supply management options reduced availability of flooded cropland and wetland habitats during fall-winter and degraded the quality of seasonal wetlands (i.e., summer-irrigation for improved forage production), though the extent and frequency of impacts varied by basin. Planned wetland restoration may substantially compensate for scenario-related effects on wetland habitats in each basin. However, results indicate that Colusa, Butte, Sutter, San Joaquin, and Tulare Basins may require additional conservation to support summer-irrigation of seasonal wetlands and winter-flooding of cropland habitats. Still further conservation may be required to provide sufficient areas of

Use of Landsat Land Surface Temperature and Vegetation Indices for Monitoring Drought in the Salt Lake Basin Area, Turkey

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Osman Orhan

2014-01-01

Full Text Available The main purpose of this paper is to investigate multitemporal land surface temperature (LST changes by using satellite remote sensing data. The study included a real-time field work performed during the overpass of Landsat-5 satellite on 21/08/2011 over Salt Lake, Turkey. Normalized vegetation index (NDVI, vegetation condition index (VCI, and temperature vegetation index (TVX were used for evaluating drought impact over the region between 1984 and 2011. In the image processing step, geometric and radiometric correction procedures were conducted to make satellite remote sensing data comparable with in situ measurements carried out using thermal infrared thermometer supported by hand-held GPS. The results showed that real-time ground and satellite remote sensing data were in good agreement with correlation coefficient (R2 values of 0.90. The remotely sensed and treated satellite images and resulting thematic indices maps showed that dramatic land surface temperature changes occurred (about 2∘C in the Salt Lake Basin area during the 28-year period (1984–2011. Analysis of air temperature data also showed increases at a rate of 1.5–2∘C during the same period. Intensification of irrigated agriculture particularly in the southern basin was also detected. The use of water supplies, especially groundwater, should be controlled considering particularly summer drought impacts on the basin.

Reservoir quality in the A2C-Stringer interval of the late Neoproterozoic Ara-Group of the South Oman Salt Basin. Diagenetic relationships in space and time

Energy Technology Data Exchange (ETDEWEB)

Becker, S. [RWTH Aachen (Germany). LuFG Reservoir Petrology; Reuning, L.; Kukla, P.A. [RWTH Aachen (Germany). Geological Inst.; Abe, S.; Li, Shiyan; Urai, J.L. [RWTH Aachen (Germany). Structural Geology, Tectonics and Geomechanics; Farqani, S.; Lopes Cardozo, G.; Rawahi, Z. [Petroleum Development Oman (Oman)

2013-08-01

The Ediacaran-Early Cambrian Ara Group of the South Oman Salt Basin consists of six carbonate to evaporite (rock salt, gypsum) sequences. These Ara Group carbonates are termed A0C to A6C from the bottom towards the top of the basin. Differential loading of locally 5 km thick Cambrian to Ordovician clastics onto the mobile rock salt of the Ara Group caused growth of isolated salt diapirs, which resulted in strong fragmentation and faulting of the carbonate intervals into several isolated so-called 'stringers'. These carbonate stringers represent a unique intra-salt petroleum system, which has been successfully explored in recent years. However, some of the stringers failed to produce at significant rates due to the complex diagenetic history from the shallow to the deep burial realm. The goal of this study is twofold. Firstly, to unravel the complex diagenesis and its relative timing and link them to the burial history of the salt basin. Secondly, to detect spatial distribution patterns of diagenetic phases and their effect on reservoir properties. Mineralogy, rock fabrics, paragenetic relationships and geochemistry of {proportional_to} 400 samples from several petroleum wells from the late Neoproterozoic A2C interval were analyzed and combined with pre-existing data. The spatial distribution of diagenetic phases and petrophysical characteristics will be displayed in field-scale distribution maps. These maps comprise crucial information for better prediction of reservoir quality in the analyzed fields, planning of new exploration wells and better volumetric calculations. An integration of the paragenetic sequence derived from thin-section analysis with results from finite element and discrete element models further helps to constrain the effect of salt tectonics on fracture formation and fluid evolution within the stringers.

Geomechanical Analysis and Design Considerations for Thin-Bedded Salt Caverns. Final Report

International Nuclear Information System (INIS)

Michael S. Bruno

2005-01-01

The bedded salt formations located throughout the United States are layered and interspersed with non-salt materials such as anhydrite, shale, dolomite and limestone. The salt layers often contain significant impurities. GRI and DOE have initialized this research proposal in order to increase the gas storage capabilities by providing operators with improved geotechnical design and operating guidelines for thin bedded salt caverns. Terralog has summarized the geologic conditions, pressure conditions, and critical design factors that may lead to: (1) Fracture in heterogeneous materials; (2) Differential deformation and bedding plane slip; (3) Propagation of damage around single and multiple cavern; and (4) Improved design recommendations for single and multiple cavern configurations in various bedded salt environments. The existing caverns within both the Permian Basin Complex and the Michigan and Appalachian Basins are normally found between 300 m to 1,000 m (1,000 ft to 3,300 ft) depth depending on local geology and salt dissolution depth. Currently, active cavern operations are found in the Midland and Anadarko Basins within the Permian Basin Complex and in the Appalachian and Michigan Basins. The Palo Duro and Delaware Basins within the Permian Basin Complex also offer salt cavern development potential. Terralog developed a number of numerical models for caverns located in thin bedded salt. A modified creep viscoplastic model has been developed and implemented in Flac3D to simulate the response of salt at the Permian, Michigan and Appalachian Basins. The formulation of the viscoplastic salt model, which is based on an empirical creep law developed for Waste Isolation Pilot Plant (WIPP) Program, is combined with the Drucker-Prager model to include the formation of damage and failure. The Permian salt lab test data provided by Pfeifle et al. 1983, are used to validate the assumptions made in the material model development. For the actual cavern simulations two

Magnetic lineations, fracture zones and seamounts in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

KameshRaju, K.A.

Magnetic and bathymetric data collected in the Central Indian Basin, between 8 degrees S and 16 degrees S lat., and 71 degrees E and 82 degrees E long. have been studied. The inferred fracture zones at 73 degrees E, 76 degrees 30'E and 79 degrees E...

The late Holocene dry period: multiproxy evidence for an extended drought between 2800 and 1850 cal yr BP across the central Great Basin, USA

Science.gov (United States)

Mensing, Scott A.; Sharpe, Saxon E.; Tunno, Irene; Sada, Don W.; Thomas, Jim M.; Starratt, Scott W.; Smith, Jeremy

2013-01-01

Evidence of a multi-centennial scale dry period between ∼2800 and 1850 cal yr BP is documented by pollen, mollusks, diatoms, and sediment in spring sediments from Stonehouse Meadow in Spring Valley, eastern central Nevada, U.S. We refer to this period as the Late Holocene Dry Period. Based on sediment recovered, Stonehouse Meadow was either absent or severely restricted in size at ∼8000 cal yr BP. Beginning ∼7500 cal yr BP, the meadow became established and persisted to ∼3000 cal yr BP when it began to dry. Comparison of the timing of this late Holocene drought record to multiple records extending from the eastern Sierra Nevada across the central Great Basin to the Great Salt Lake support the interpretation that this dry period was regional. The beginning and ending dates vary among sites, but all sites record multiple centuries of dry climate between 2500 and 1900 cal yr BP. This duration makes it the longest persistent dry period within the late Holocene. In contrast, sites in the northern Great Basin record either no clear evidence of drought, or have wetter than average climate during this period, suggesting that the northern boundary between wet and dry climates may have been between about 40° and 42° N latitude. This dry in the southwest and wet in the northwest precipitation pattern across the Great Basin is supported by large-scale spatial climate pattern hypotheses involving ENSO, PDO, AMO, and the position of the Aleutian Low and North Pacific High, particularly during winter.

Subsurface geology of a potential waste emplacement site, Salt Valley Anticline, Grand County, Utah

Science.gov (United States)

Hite, R.J.

1977-01-01

The Salt Valley anticline, which is located about 32 km northeast of Moab, Utah, is perhaps one of the most favorable waste emplacement sites in the Paradox basin. The site, which includes about 7.8 km 2, is highly accessible and is adjacent to a railroad. The anticline is one of a series of northwest-trending salt anticlines lying along the northeast edge of the Paradox basin. These anticlines are cored by evaporites of the Paradox Member of the Hermosa Formation of Middle Pennsylvanian age. The central core of the Salt Valley anticline forms a ridgelike mass of evaporites that has an estimated amplitude of 3,600 m. The evaporite core consists of about 87 percent halite rock, which includes some potash deposits; the remainder is black shale, silty dolomite, and anhydrite. The latter three lithologies are referred to as 'marker beds.' Using geophysical logs from drill holes on the anticline, it is possible to demonstrate that the marker beds are complexly folded and faulted. Available data concerning the geothermal gradient and heatflow at the site indicate that heat from emplaced wastes should be rapidly dissipated. Potentially exploitable resources of potash and petroleum are present at Salt Valley. Development of these resources may conflict with use of the site for waste emplacement.

Subsurface geology of a potential waste emplacement site, Salt Valley Anticline, Grand County, Utah

International Nuclear Information System (INIS)

Hite, R.J.

1977-01-01

The Salt Valley anticline, which is located about 32 km northeast of Moab, Utah, is perhaps one of the most favorable waste emplacement sites in the Paradox basin. The site, which includes about 7.8 km 2 , is highly accessible and is adjacent to a railroad. The anticline is one of a series of northwest-trending salt antilcines lying along the northeast edge of the Paradox basin. These anticlines are cored by evaporites of the Paradox Member of the Hermosa Formation of Middle Pennsylvanian age. The central core of the Salt Valley anticline forms a ridgelike mass of evaporites that has an estimated amplitude of 3,600 m. The evaporite core consists of about 87 percent halite rock, which includes some potash deposits; the remainder is black shale, silty dolomite, and anhydrite. The latter three lithologies are referred to as ''marker beds.'' Using geophysical logs from drill holes on the anticline, it is possible to demonstrate that the marker beds are complexly folded and faulted. Available data concerning the geothermal gradient and heatflow at the site indicate that heat from emplaced wastes should be rapidly dissipated. Potentially exploitable resources of potash and petroleum are present at Salt Valley. Development of these resources may conflict with use of the site for waste emplacement

Salt or ice diapirism origin for the honeycomb terrain in Hellas basin, Mars?: Implications for the early martian climate

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Weiss, David K.; Head, James W.

2017-03-01

The "honeycomb" terrain is a Noachian-aged cluster of ∼7 km wide linear cell-like depressions located on the northwestern floor of Hellas basin, Mars. A variety of origins have been proposed for the honeycomb terrain, including deformation rings of subglacial sediment, frozen convection cells from a Hellas impact melt sheet, a swarm of igneous batholiths, salt diapirism, and ice diapirism. Recent work has shown that the salt or ice diapirism scenarios appear to be most consistent with the morphology and morphometry of the honeycomb terrain. The salt and ice diapirism scenarios have different implications for the ancient martian climate and hydrological cycle, and so distinguishing between the two scenarios is critical. In this study, we specifically test whether the honeycomb terrain is consistent with a salt or ice diapir origin. We use thermal modeling to assess the stability limits on the thickness of an ice or salt diapir-forming layer at depth within the Hellas basin. We also apply analytical models for diapir formation to evaluate the predicted diapir wavelengths in order to compare with observations. Ice diapirism is generally predicted to reproduce the observed honeycomb wavelengths for ∼100 m to ∼1 km thick ice deposits. Gypsum and kieserite diapirism is generally predicted to reproduce the observed honeycomb wavelengths for ≥ 600-1000 m thick salt deposits, but only with a basaltic overburden. Halite diapirism generally requires approx. ≥ 1 km thick halite deposits in order to reproduce the observed honeycomb wavelengths. Hellas basin is a distinctive environment for diapirism on Mars due to its thin crust (which reduces surface heat flux), low elevation (which allows Hellas to act as a water/ice/sediment sink and increases the surface temperature), and location within the southern highlands (which may provide proximity to inflowing saline water or glacial ice). The plausibility of an ice diapir mechanism generally requires temperatures ≤ 250

Assessment of shale-oil resources of the Central Sumatra Basin, Indonesia, 2015

Science.gov (United States)

Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Tennyson, Marilyn E.; Mercier, Tracey J.; Brownfield, Michael E.; Pitman, Janet K.; Gaswirth, Stephanie B.; Leathers-Miller, Heidi M.

2015-11-12

Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 459 million barrels of shale oil, 275 billion cubic feet of associated gas, and 23 million barrels of natural gas liquids in the Central Sumatra Basin, Indonesia.

Sup(10)Be variation in surficial sediments of the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Nath, B.N.; Aldahan, A.; Possnert, G.; Selvaraj, K.; Mascarenhas-Pereira, M.B.L.; Chen, C.T.A.

Distribution of 10Be in systematically collected (degree + degree interval at 10 to 16 degrees S; 73.5 to 76.5 degrees E) surficial siliceous ooze, siliceous clay and pelagic clay sediments (top 2 cm) from the abyssal Central Indian Basin...

Age, extent and carbon storage of the central Congo Basin peatland complex.

Science.gov (United States)

Dargie, Greta C; Lewis, Simon L; Lawson, Ian T; Mitchard, Edward T A; Page, Susan E; Bocko, Yannick E; Ifo, Suspense A

2017-02-02

Peatlands are carbon-rich ecosystems that cover just three per cent of Earth's land surface, but store one-third of soil carbon. Peat soils are formed by the build-up of partially decomposed organic matter under waterlogged anoxic conditions. Most peat is found in cool climatic regions where unimpeded decomposition is slower, but deposits are also found under some tropical swamp forests. Here we present field measurements from one of the world's most extensive regions of swamp forest, the Cuvette Centrale depression in the central Congo Basin. We find extensive peat deposits beneath the swamp forest vegetation (peat defined as material with an organic matter content of at least 65 per cent to a depth of at least 0.3 metres). Radiocarbon dates indicate that peat began accumulating from about 10,600 years ago, coincident with the onset of more humid conditions in central Africa at the beginning of the Holocene. The peatlands occupy large interfluvial basins, and seem to be largely rain-fed and ombrotrophic-like (of low nutrient status) systems. Although the peat layer is relatively shallow (with a maximum depth of 5.9 metres and a median depth of 2.0 metres), by combining in situ and remotely sensed data, we estimate the area of peat to be approximately 145,500 square kilometres (95 per cent confidence interval of 131,900-156,400 square kilometres), making the Cuvette Centrale the most extensive peatland complex in the tropics. This area is more than five times the maximum possible area reported for the Congo Basin in a recent synthesis of pantropical peat extent. We estimate that the peatlands store approximately 30.6 petagrams (30.6 × 10 15  grams) of carbon belowground (95 per cent confidence interval of 6.3-46.8 petagrams of carbon)-a quantity that is similar to the above-ground carbon stocks of the tropical forests of the entire Congo Basin. Our result for the Cuvette Centrale increases the best estimate of global tropical peatland carbon stocks by

Water-quality assessment of the Central Arizona Basins, Arizona and northern Mexico; environmental setting and overview of water quality

Science.gov (United States)

Cordy, Gail E.; Rees, Julie A.; Edmonds, Robert J.; Gebler, Joseph B.; Wirt, Laurie; Gellenbeck, Dorinda J.; Anning, David W.

1998-01-01

The Central Arizona Basins study area in central and southern Arizona and northern Mexico is one of 60 study units that are part of the U.S. Geological Survey's National Water-Quality Assessment program. The purpose of this report is to describe the physical, chemical, and environmental characteristics that may affect water quality in the Central Arizona Basins study area and present an overview of water quality. Covering 34,700 square miles, the study area is characterized by generally north to northwestward-trending mountain ranges separated by broad, gently sloping alluvial valleys. Most of the perennial rivers and streams are in the northern part of the study area. Rivers and streams in the south are predominantly intermittent or ephemeral and flow in response to precipitation such as summer thunderstorms. Effluent-dependent streams do provide perennial flow in some reaches. The major aquifers in the study area are in the basin-fill deposits that may be as much as 12,000 feet thick. The 1990 population in the study area was about 3.45 million, and about 61 percent of the total was in Maricopa County (Phoenix and surrounding cities). Extensive population growth over the past decade has resulted in a twofold increase in urban land areas and increased municipal water use; however, agriculture remains the major water use. Seventy-three percent of all water with drawn in the study area during 1990 was used for agricultural purposes. The largest rivers in the study area-the Gila, Salt, and Verde-are perennial near their headwaters but become intermittent downstream because of impoundments and artificial diversions. As a result, the Central Arizona Basins study area is unique compared to less arid basins because the mean surface-water outflow is only 528 cubic feet per second from a total drainage area of 49,650 square miles. Peak flows in the northern part of the study area are the result of snowmelt runoff; whereas, summer thunderstorms account for the peak flows in

Geohydrology of the northern Louisiana salt-dome basin pertinent to the storage of radioactive wastes; a progress report

Science.gov (United States)

Hosman, R.L.

1978-01-01

Salt domes in northern Louisiana are being considered as possible storage sites for nuclear wastes. The domes are in an area that received regional sedimentation through early Tertiary (Eocene) time with lesser amounts of Quaternary deposits. The Cretaceous-Tertiary accumulation is a few thousand feet thick; the major sands are regional aquifers that extend far beyond the boundaries of the salt-dome basin. Because of multiple aquifers, structural deformation, and variations in the hydraulic characteristics of cap rock, the ground-water hydrology around a salt dome may be highly complex. The Sparta Sand is the most productive and heavily used regional aquifer. It is either penetrated by or overlies most of the domes. A fluid entering the Sparta flow system would move toward one of the pumping centers, all at or near municipalities that pump from the Sparta. Movement could be toward surface drainage where local geologic and hydrologic conditions permit leakage to the surface or to a surficial aquifer. (Woodard-USGS)

Paleogene Sediment Character of Mountain Front Central Sumatra Basin

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P. A. Suandhi

2014-07-01

Full Text Available DOI: 10.17014/ijog.v8i3.164The SE-NW trending Mountain Front of Central Sumatra Basin is located in the southern part of the basin. The Mountain Front is elongated parallel to the Bukit Barisan Mountain, extending from the Regencies of North Padang Lawas (Gunung Tua in the northwest, Rokan Hulu, Kampar, Kuantan Singingi, and Inderagiri Hulu Regency in the southeast. The Palaeogene sediments also represent potential exploration objectives in Central Sumatra Basin, especially in the mountain front area. Limited detailed Palaeogene sedimentology information cause difficulties in hydrocarbon exploration in this area. Latest age information and attractive sediment characters based on recent geological fieldwork (by chaining method infer Palaeogene sediment potential of the area. The Palaeogene sedimentary rock of the mountain front is elongated from northwest to southeast. Thickness of the sedimentary unit varies between 240 - 900 m. Palynology samples collected recently indicate that the oldest sedimentary unit is Middle Eocene and the youngest one is Late Oligocene. This latest age information will certainly cause significant changes to the existing surface geological map of the mountain front area. Generally, the Palaeogene sediments of the mountain front area are syn-rift sediments. The lower part of the Palaeogene deposit consists of fluvial facies of alluvial fan and braided river facies sediments. The middle part consists of fluvial meandering facies, lacustrine delta facies, and turbidity lacustrine facies sediments. The upper part consists of fluvial braided facies and transitional marine facies sediments. Volcanism in the area is detected from the occurrence of volcanic material as lithic material and spotted bentonite layers in the middle part of the mountain front area. Late rifting phase is indicated by the presence of transitional marine facies in the upper part of the Palaeogene sediments.

Folding and fracturing of rock adjacent to salt diapirs

Science.gov (United States)

Rowan, Mark G.

2017-04-01

When John Ramsay wrote his groundbreaking book in 1967, deformation around salt diapirs was not something he covered. At the time, most geologists considered diapirs to form due to density inversion, rising through thick overlying strata due to buoyancy. In doing so, salt was thought to shove aside the younger rocks, shearing and fracturing them in drag folds and supposedly producing "salt gouge". Even after it was realized that the majority of diapirs spend most of their history growing at or just beneath the surface, the relative rise of salt and sinking of minibasins were (and are) still thought by many to be accommodated in part by shear and fracturing of rocks in a collar zone around the salt. There are two arguments against this model. The first is mechanical: whereas halite behaves as a viscous fluid, even young sediment deforms as a brittle material with layer anisotropy. Thus, the salt-sediment interface is the outer margin of an intrasalt shear zone caused by viscous drag against the diapir margin. The velocity of salt flow decreases dramatically toward the edge of the diapir, so that the outermost salt effectively doesn't move. Hence, no shear or fracturing is expected in surrounding strata. The second and more important argument is that empirical field data do not support the idea of drag folds and associated deformation. Certainly, strata are typically folded and thinned adjacent to diapirs. However, stratal upturn is generated by monoclinal drape folding of the diapir roof over the edge of the rising salt, and thinning is caused by deposition onto the bathymetric highs formed by the diapirs, often supplemented by roof erosion and slumping. Halokinetic sequences observed in numerous salt basins (e.g., Paradox Basin, La Popa Basin, Spanish Pyrenees, Sivas Basin, Zagros Mountains, Kuqa Basin) contain no diapir-parallel shear zones and minimal thinning and fracturing caused by diapir rise. Even megaflaps, in which strata extend for kilometers up the sides

Macrobenthic standing stock in the nodule areas of Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Pavithran, S.; Ingole, B.S.

Diversity, distribution and standing stock of macrofauna in the nodule areas of Central Indian Ocean Basin (CIOB) were studied during April 2003. The density ranged between 22 to 132 no.m super(-2) (mean: 55 + or - 37 SD, n=25) and biomass ranged...

New ichthyoliths from ferromanganese crusts and nodules from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Gupta, S.M.

Ferromanganese encrusted hardgrounds, their intraclasts and the nuclei of manganese nodules collected from the Central Indian Ocean basin have yielded plentiful numbers of ichthyoliths. Forty well-knon ichthyoliths, one new type and 35 new subtypes...

Integrated geophysical study of the Triassic salt bodies' geometry and evolution in central Tunisia

Science.gov (United States)

Azaiez, Hajer; Amri, Dorra Tanfous; Gabtni, Hakim; Bedir, Mourad; Soussi, Mohamed

2008-01-01

A comprehensive study, integrating gravity, magnetic and seismic reflection data, has been used to resolve the complex Triassic salt body geometry and evolution in central Tunisia. Regional seismic lines across the study area show a detachment level in the Upper Triassic evaporites, associated with chaotic seismic facies below the Souinia, Majoura, and Mezzouna structures. The Jurassic and Lower Cretaceous seismic horizons display pinching-outs and onlapping around these structures. A stack-velocity section confirms the existence of a high-velocity body beneath the Souinia Mountain. Regional gravity and magnetic profiles in this area were elaborated from ETAP (the Tunisian Firm of Petroleum Activities) measure stations. These profiles were plotted following the same layout from the west (Souinia) to the east (Mezzouna), across the Majoura and Kharrouba mountains. They highlight associated gravity and magnetic negative anomalies. These gravity and magnetic data coupled to the reflection seismic data demonstrate that, in the Souinia, Majoura, and El Hafey zones, the Triassic salt reaches a salt pillow and a salt-dome stage, without piercing the cover. These stages are expressed by moderately low gravity anomalies. On the other hand, in the Mezzouna area (part of the North-South Axis), the Triassic salt had pierced its cover during the Upper Cretaceous and the Tertiary, reaching a more advanced stage as a salt diapir and salt wall. These stages express important low gravity and magnetic anomalies. These results confirm the model of Tanfous et al. (2005) of halokinetic movements by fault intrusions inducing, from the west to the east, structures at different stages of salt pillow, salt dome, and salt diapir.

Recovery of deep-sea meiofauna after artificial disturbance in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Ingole, B.S.; Goltekar, N.R.; Gonsalves, S.; Ansari, Z.A.

-1 1 Recovery of Deep-sea Meiofauna after Artificial Disturbance in the Central Indian Basin INGOLE B.S*., R. GOLTEKAR, S. GONSALVES and Z. A. ANSARI Biological Oceanography Division, National Institute of Oceanography, Dona Paula, Goa; 403004...

Overview of ONWI'S Salt site selection program

International Nuclear Information System (INIS)

Madia, W.J.

1983-01-01

In the past year, activities in the salt site selection program of the Office of Nuclear Waste Isolation (ONWI) have focused on narrowing the number and size of areas under consideration as candidate repository sites. The progressive focusing is illustrated. Bedded salt, in the Permian Basin of West Texas and the Paradox Basin of Utah, and salt domes in the Gulf Coast Salt Dome Region (including parts of East Texas, Louisiana, and Mississippi) have been the subjects of geologic, environmental, and socioeconomic characterization of progressively greater detail as the screening process has proceeded. Detailed, field-oriented research and testing have superceded broad-based studies relying heavily on literature and other existing data. Coinciding with the increased field activities has been the publication of results and recommendations resulting from earlier program efforts

Simulation of the Lower Walker River Basin hydrologic system, west-central Nevada, using PRMS and MODFLOW models

Science.gov (United States)

Allander, Kip K.; Niswonger, Richard G.; Jeton, Anne E.

2014-01-01

Walker Lake is a terminal lake in west-central Nevada with almost all outflow occurring through evaporation. Diversions from Walker River since the early 1900s have contributed to a substantial reduction in flow entering Walker Lake. As a result, the lake is receding, and salt concentrations have increased to a level in which Oncorhynchus clarkii henshawi (Lahontan Cutthroat trout) are no longer present, and the lake ecosystem is threatened. Consequently, there is a concerted effort to restore the Walker Lake ecosystem and fishery to a level that is more sustainable. However, Walker Lake is interlinked with the lower Walker River and adjacent groundwater system which makes it difficult to understand the full effect of upstream water-management actions on the overall hydrologic system including the lake level, volume, and dissolved-solids concentrations of Walker Lake. To understand the effects of water-management actions on the lower Walker River Basin hydrologic system, a watershed model and groundwater flow model have been developed by the U.S. Geological Survey in cooperation with the Bureau of Reclamation and the National Fish and Wildlife Foundation.

Geochemistry of metal-rich brines from central Mississippi Salt Dome basin, U.S.A.

Science.gov (United States)

Kharaka, Y.K.; Maest, A.S.; Carothers, W.W.; Law, L.M.; Lamothe, P.J.; Fries, T.L.

1987-01-01

Oil-field brines are the most favored ore-forming solutions for the sediment-hosted Mississippi Valley-type ore deposits. Detailed inorganic and organic chemical and isotope analyses of water and gas samples from six oil fields in central Mississippi, one of the very few areas with high metal brines, were conducted to study the inorganic and organic complexes responsible for the high concentrations of these metals. The samples were obtained from production zones consisting of sandstone and limestone that range in depth from 1900 to 4000 m (70-120??C) and in age from Late Cretaceous to Late Jurassic. Results show that the waters are dominantly bittern brines related to the Louann Salt. The brines have extremely high salinities that range from 160,000 to 320,000 mg/l total dissolved solids and are NaCaCl-type waters with very high concentrations of Ca (up to 48,000 mg/l) and other alkaline-earth metals, but with low concentrations of aliphatic acid anions. The concentrations of metals in many water samples are very high, reaching values of 70 mg/l for Pb, 245 mg/l for Zn, 465 mg/l for Fe and 210 mg/l for Mn. The samples with high metal contents have extremely low concentrations (<0.02 mg/l) of H2S. Samples obtained from the Smackover Formation (limestone) have low metal contents that are more typical of oil-field waters, but have very high concentrations (up to 85 mg/l) of H2S. Computations with the geochemical code SOLMINEQ.87 give the following results: (1) both Pb and Zn are present predominantly as aqueous chloride complexes (mainly as PbCl42- and ZnCl42-, respectively); (2) the concentrations of metals complexed with short-chained aliphatic acid anions and reduced S species are minor; (3) organic acid anions are important in controlling the concentrations of metals because they affect the pH and buffer capacity of the waters at subsurface conditions; and (4) galena and sphalerite solubilities control the concentrations of Pb and Zn in these waters. ?? 1988.

Pore Pressure and Field stress variation from Salt Water Injection; A case Study from Beaver Lodge Field in Williston Basin

Science.gov (United States)

Mohammed, R. A.; Khatibi, S.

2017-12-01

One of the major concerns in producing from oil and gas reservoirs in North American Basins is the disposal of high salinity salt water. It is a misconception that Hydro frack triggers Earthquakes, but due to the high salinity and density of water being pumped to the formation that has pore space of the rock already filled, which is not the case in Hydro-frack or Enhanced Oil Recovery in which fracturing fluid is pumped into empty pore space of rocks in depleted reservoirs. A review on the Bakken history showed that the concerns related to induce seismicity has increased over time due to variations in Pore pressure and In-situ stress that have shown steep changes in the region over the time. In this study, we focused on Pore pressure and field Stress variations in lower Cretaceous Inyan Kara and Mississippian Devonian Bakken, Inyan Kara is the major source for class-II salt-water disposal in the basin. Salt-water disposal is the major cause for induced seismicity. A full field study was done on Beaver Lodge Field, which has many salt-water disposal wells Adjacent to Oil and Gas Wells. We analyzed formation properties, stresses, pore-pressure, and fracture gradient profile in the field and. The constructed Mechanical Earth Model (MEM) revealed changes in pore pressure and stresses over time due to saltwater injection. Well drilled in the past were compared to recently drilled wells, which showed much stress variations. Safe mud weight Window of wells near proximity of injection wells was examined which showed many cases of wellbore instabilities. Results of this study will have tremendous impact in studying environmental issues and the future drilling and Fracking operations.

Disposal alternatives and recommendations for waste salt management for repository excavation in the Palo Duro Basin, Texas

International Nuclear Information System (INIS)

1987-01-01

This report documents an evaluation of five alternatives for the disposal of waste salt that would be generated by the construction of a repository for radioactive waste in underground salt deposits at either of two sites in the Palo Duro Basin, Texas. The alternatives include commercial disposal, offsite deep-well injection, disposal in abandoned mines, ocean disposal, and land surface disposal on or off the site. For each alternative a reference case was rated - positive, neutral, or negative - in terms of environmental and dependability factors developed specifically for Texas sites. The factors constituting the environmental checklist relate to water quality impact, water- and land-use conflicts, ecological compatibility, conformity with air quality standards, and aesthetic impact. Factors on the dependability check-list relate to public acceptance, the adequacy of site characterization, permit and licensing requirements, technological requirements, and operational availability. A comparison of the ratings yielded the following viable alternatives, in order of preference: (1) land surface disposal, specifically disposal on tailings piles associated with abandoned potash mines; (2) disposal in abandoned mines, specifically potash mines; and (3) commercial disposal. Approaches to the further study of these three salt management techniques are recommended

Tectonic Evolution of the Çayirhan Neogene Basin (Ankara), Central Turkey

Science.gov (United States)

Behzad, Bezhan; Koral, Hayrettin; İşb&idot; l, Duygu; Karaaǧa; ç, Serdal

2016-04-01

Çayırhan (Ankara) is located at crossroads of the Western Anatolian extensional region, analogous to the Basin and Range Province, and suture zone of the Neotethys-Ocean, which is locus of the North Anatolian Transform since the Late Miocene. To the north of Çayırhan (Ankara), a Neogene sedimentary basin comprises Lower-Middle Miocene and Upper Miocene age formations, characterized by swamp, fluvial and lacustrine settings respectively. This sequence is folded and transected by neotectonic faults. The Sekli thrust fault is older than the Lower-Middle Miocene age formations. The Davutoǧlan fault is younger than the Lower-Middle Miocene formations and is contemporaneous to the Upper Miocene formation. The Çatalkaya fault is younger than the Upper Miocene formation. The sedimentary and tectonic features provide information on mode, timing and evolution of this Neogene age sedimentary basin in Central Turkey. It is concluded that the region underwent a period of uplift and erosion under the influence of contractional tectonics prior to the Early-Middle Miocene, before becoming a semi-closed basin under influence of transtensional tectonics during the Early-Middle Miocene and under influence of predominantly extensional tectonics during the post-Late Miocene times. Keywords: Tectonics, Extension, Transtension, Stratigraphy, Neotectonic features.

Preliminary description of hydrologic characteristics and contaminant transport potential of rocks in the Pasco Basin, south-central Washington

International Nuclear Information System (INIS)

Deju, R.A.; Fecht, K.R.

1979-03-01

This report aims at consolidating existing data useful in defining the hydrologic characteristics of the Pasco Basin within south-central Washington. It also aims at compiling the properties required to evaluate contaminant transport potential within individual subsurface strata in this basin. The Pasco Basin itself is a tract of semi-arid land covering about 2,000 square miles in south-central Washington. The regional geology of this basin is dominated by tholeiitic flood basalts of the Columbia Plateau. The surface hydrology of the basin is dominated by the Yakima, Snake, and Columbia rivers. Short-lived ephemeral streams may flow for a short period of time after a heavy rainfall or snowmelt. The subsurface hydrology of the Pasco Basin is characterized by an unconfined aquifer carrying the bulk of the water discharged within the basin. This aquifer overlies a series of confined aquifers carrying progressively smaller amounts of groundwater as a function of depth. The hydraulic properties of the various aquifers and non-water-bearing strata are characterized and reported. A summary of the basic properties is tabulated. The hydrochemical data obtained are summarized. The contaminant transport properties of the rocks in the Pasco Basin are analyzed with emphasis on the dispersion and sorption coefficients and the characteristics of the potential reactions between emplaced waste and the surrounding medium. Some basic modeling considerations of the hydrogeologic systems in the basin with a brief discussion of model input requirements and their relationship to available data are presented

Mineralogy of polymetallic nodules and associated sediments from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P

in montmorillonite, chlorite and illite, delta MnO sub(2) is the dominant mineral phase in the nodules of the southern Central Indian Ocean Basin. These nodules have a smooth surface texture, are relatively rich in Fe and Co, and are associated with pelagic clay...

Hydrothermal signature in ferromanganese oxide coatings on pumice from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Kalangutkar, N.G.; Iyer, S.D.; Mascarenhas-Pereira, M.B.L.; Nath, B.N.

Mineralogical and elemental analyses of 20 ferromanganese (FeMn)-coated pumice samples from the Central Indian Ocean Basin (CIOB) indicate that todorokite is the major mineral phase, whereas vernadite occurs only rarely. Based on major, trace...

Rare earth element patterns of the Central Indian Basin sediments related to their lithology

Digital Repository Service at National Institute of Oceanography (India)

Nath, B.N.; Roelandts, I.; Sudhakar, M.; Pluger, W.L.

Rare earth element (REE) concentration have been determined in terrigenous, siliceous (nodule barren and nodule bearing), calcareous, and red clay from the Central Indian Basin. The bulk distribution of REE, and in particular the relative cerium...

Petrology of seamounts in the Central Indian Ocean Basin: Evidence for near-axis origin

Digital Repository Service at National Institute of Oceanography (India)

Mukhopadhyay, R.; Batiza, R.; Iyer, S.D.

Previous studies on the distribution and morphology of ancient seamount chains (>50 Ma) in the Central Indian Ocean basin (CIOB) indicated their generation from the fast spreading Southeast Indian Ridge. The petrology of some of these seamounts...

The origin of ferro-manganese oxide coated pumice from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Pearce, N.J.G.; Parthiban, G.; Smith, V.C.; Mudholkar, A.V.; Rao, N.R

Pumice clasts, partially and fully coated with ferro-manganese oxide from the Central Indian Ocean Basin (CIOB) were analysed for major, trace and rare earth elements; and glass and mineral grain chemistry to assess their possible source...

Inter-relationship between nuclei and gross characteristics of manganese nodules, Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Sarkar, C; Iyer, S.D.; Hazra, S.

More than 200 samples of manganese nodules from the Central Indian Ocean Basin (CIOB) were studied for their different parameters. The study included various aspects such as morphology, texture, mineralogy, and composition of the nodules. The nuclei...

Geology and undiscovered resource assessment of the potash-bearing Pripyat and Dnieper-Donets Basins, Belarus and Ukraine

Science.gov (United States)

Cocker, Mark D.; Orris, Greta J.; Dunlap, Pamela; Lipin, Bruce R.; Ludington, Steve; Ryan, Robert J.; Słowakiewicz, Mirosław; Spanski, Gregory T.; Wynn, Jeff; Yang, Chao

2017-08-03

Undiscovered potash resources in the Pripyat Basin, Belarus, and Dnieper-Donets Basin, Ukraine, were assessed as part of a global mineral resource assessment led by the U.S. Geological Survey (USGS). The Pripyat Basin (in Belarus) and the Dnieper-Donets Basin (in Ukraine and southern Belarus) host stratabound and halokinetic Upper Devonian (Frasnian and Famennian) and Permian (Cisuralian) potash-bearing salt. The evaporite basins formed in the Donbass-Pripyat Rift, a Neoproterozoic continental rift structure that was reactivated during the Late Devonian and was flooded by seawater. Though the rift was divided, in part by volcanic deposits, into the separate Pripyat and Dnieper-Donets Basins, both basins contain similar potash‑bearing evaporite sequences. An Early Permian (Cisuralian) sag basin formed over the rift structure and was also inundated by seawater resulting in another sequence of evaporite deposition. Halokinetic activity initiated by basement faulting during the Devonian continued at least into the Permian and influenced potash salt deposition and structural evolution of potash-bearing salt in both basins.Within these basins, four areas (permissive tracts) that permit the presence of undiscovered potash deposits were defined by using geological criteria. Three tracts are permissive for stratabound potash-bearing deposits and include Famennian (Upper Devonian) salt in the Pripyat Basin, and Famennian and Cisuralian (lower Permian) salt in the Dnieper-Donets Basin. In addition, a tract was delineated for halokinetic potash-bearing Famennian salt in the Dnieper-Donets Basin.The Pripyat Basin is the third largest source of potash in the world, producing 6.4 million metric tons of potassium chloride (KCl) (the equivalent of about 4.0 million metric tons of potassium oxide or K2O) in 2012. Potash production began in 1963 in the Starobin #1 mine, near the town of Starobin, Belarus, in the northwestern corner of the basin. Potash is currently produced from

REVITALIZATION OF DEGRADED AREAS OF THE TUZLA BASIN AND FORMING ARTIFICIAL LAKES IN THE FUNCTION OF TOURISM DEVELOPMENT

Directory of Open Access Journals (Sweden)

SENADA NEZIROVIĆ

2016-03-01

Full Text Available The Tuzla basin is located in the central part of the region of north-eastern Bosnia. It covers an area of 1,405 km² consisting of five municipalities:Tuzla, Ţivinice, Lukavac, Banovići and Kalesija. It is surrounded by mountains Majevica, Ozren, Konjuh and Javornik. It has a favorable geo-traffic position because it represents the intersection of roads leading to Belgrade,Orašje, Sarajevo and Doboj. The area of Tuzla basin has significant resources of coal and rock salt on the basis of which was developed chemical industry.The period of industrialization has considerably affected the economic situation of the entire region, and particularly the development of the central places of the Tuzla basin. Intensive exploitation of rock salt has significantly influenced the subsidence in the metropolitan area of Tuzla and turned it into an unordered wetlands. After the end of coal mining in the abandoned mining pits in the area of the municipalities of Ţivinice, Tuzla and Banovići were formed lake depressions. In order to improve and protect the environment, there were implemented several environmental projects which reconstructed coastal areas of lakes in the area of Ţivinice, Tuzla, Lukavac and Banovići, and in the metropolitan area of Tuzla there were built three artificial salt lakes in the function of the city outdoor pool.The paper places particular emphasis on the promotion of values of artificial lakes created by revitalization of degraded areas in the Tuzla basin and future directions in the development of the same. Moreover, considerable attention is given to the system of planned realisation of environmental projects for the improvement of environment in the towns of Tuzla, Ţivinice, Lukavac, Banovići and solving environmental problems.The aim of this study is to point out the proper management and use of hydrographic resources in the function of tourism development in the area of the Tuzla basin.

Slope instability in the Bastardo Basin (Umbria, Central Italy – The landslide of Barattano

Directory of Open Access Journals (Sweden)

C. Cencetti

2003-01-01

Full Text Available The Bastardo Basin is one of the classics Apenninic intermontane basins of central Italy. They are en-closed tectonic basins (graben and semigraben with high anthropization, but with high vulnerability, too (seismic, hydrogeological and geomorphological. The paper concerns some aspects about slope instability in the Bastardo Basin as part of a wider research, which aims to actually define the characteristics of the liability to landslides of the Apenninic intermontane basins. In particular lithological, stratigraphical and hydrogeological conditions are analysed under which a landslide near village of Barattano has developed. This mass movement, at different times, produced partial or total occlusion of the torrent Puglia. Here geognostic investigations together with laboratory tests and subsequent monitoring of landslide area were carried out.  A back analysis, based on limit equilibrium solutions for the factor of safety of the slope, provided the residual strenght properties of the soil mass along the sliding surface.   The landslide of Barattano is representative of a very frequent situation (in terms of type, factors and causes of the movement, possible development of the movement not only within Bastardo Basin, but in general within Apenninic intermontane basins, too.  The study of landslide and the design of appropriate remedial measures are of great importance in terms of prevention and mitigation of geologic-hydraulic risk in Apenninic intermontane basins.

An outline of neotectonic structures and morphotectonics of the western and central Pannonian basin.

NARCIS (Netherlands)

Fodor, L.; Bada, G.; Csillag, G.; Horvath, E.; Ruszkiczay-Rudiger, Z.; Klara, P.; Sikhegyi, F.; Timár, G.; Cloetingh, S.A.P.L.; Horvath, F.

2005-01-01

Neotectonic deformation in the western and central part of the Pannonian Basin was investigated by means of surface and subsurface structural analyses, and geomorphologic observations. The applied methodology includes the study of outcrops, industrial seismic profiles, digital elevation models,

Benthic environmental baseline investigations in the manganese nodule area of the central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.; Nath, B.N.; Gupta, S.M.; Ansari, Z.A.

In order to exploit the manganese nodule deposits in future, an assessment of the environmental impact due to potential mining activity, has been undertaken in the Central Indian Basin Under this programme, seabed surveys in five selected areas have...

Availability of water resources in the rio Bermudez micro-basin. Central Region of Costa Rica

International Nuclear Information System (INIS)

Hernando Echevarria, L.; Orozco Montoya, R.

2015-01-01

The Rio Bermudez micro-basin makes up part of the principal hydrological resource area in the Central Region of Costa Rica. For this reason a study was done to determine the availability of hydrological resources in said micro-basin to identify areas with potential water availability problems. A monthly water balance was calculated using land use, geomorphology and climate parameters. From these water balance studies, the amount of available water was calculated and classified into four categories, however, in this micro-basin, only three categories were identified: high, medium and moderate water availability. No areas were identified with low water availability, indicating availability is sufficient; however, there is increasing demand on water resources because over half of the micro-basin area is classified as having moderate water availability. (Author)

Quantifying drag on wellbore casings in moving salt sheets

Science.gov (United States)

Weijermars, R.; Jackson, M. P. A.; Dooley, T. P.

2014-08-01

Frontier hydrocarbon development projects in the deepwater slopes of the Gulf of Mexico Basin, Santos Basin and Lower Congo Basin all require wells to cross ductile layers of autochthonous or allochthonous salt moving at peak rates of 100 mm yr-1. The Couette-Poiseuille number is introduced here to help pinpoint the depth of shear stress reversal in such salt layers. For any well-planned through salt, the probable range of creep forces of moving salt needs to be taken into account when designing safety margins and load-factor tolerance of the well casing. Drag forces increase with wellbore diameter, but more significantly with effective viscosity and speed of the creeping salt layer. The potential drag forces on cased wellbores in moving salt sheets are estimated analytically using a range of salt viscosities (1015-1019 Pa s) and creep rates (0-10 mm yr-1). Drag on perfectly rigid casing of infinite strength may reach up to 13 Giga Newton per meter wellbore length in salt having a viscosity of 1019 Pa s. Well designers may delay stress accumulations due to salt drag when flexible casing accommodates some of the early displacement and strain. However, all creeping salt could displace, fracture and disconnect well casing, eventually. The shear strength of typical heavy duty well casing (about 1000 MPa) can be reached due to drag by moving salt. Internal flow of salt will then fracture the casing near salt entry and exit points, but the structural damage is likely to remain unnoticed early in the well-life when the horizontal shift of the wellbore is still negligibly small (at less than 1 cm yr-1). Disruption of casing and production flow lines within the anticipated service lifetime of a well remains a significant risk factor within distinct zones of low-viscosity salt which may reach ultrafast creep rates of 100 mm yr-1.

Elements of an environmental decision support system for seasonal wetland salt management in a river basin subjected to water quality regulation

Energy Technology Data Exchange (ETDEWEB)

Quinn, N.W.T.

2009-06-01

Seasonally managed wetlands in the Grasslands Basin on the west-side of California's San Joaquin Valley provide food and shelter for migratory wildfowl during winter months and sport for waterfowl hunters during the annual duck season. Surface water supply to these wetlands contain salt which, when drained to the San Joaquin River during the annual drawdown period, can negatively impact water quality and cause concern to downstream agricultural riparian water diverters. Recent environmental regulation, limiting discharges salinity to the San Joaquin River and primarily targeting agricultural non-point sources, now also targets return flows from seasonally managed wetlands. Real-time water quality management has been advocated as a means of continuously matching salt loads discharged from agricultural, wetland and municipal operations to the assimilative capacity of the San Joaquin River. Past attempts to build environmental monitoring and decision support systems (EDSS's) to implement this concept have enjoyed limited success for reasons that are discussed in this paper. These reasons are discussed in the context of more general challenges facing the successful implementation of a comprehensive environmental monitoring, modelling and decision support system for the San Joaquin River Basin.

Spatial analysis from remotely sensed observations of Congo basin of East African high Land to drain water using gravity for sustainable management of low laying Chad basin of Central Africa

OpenAIRE

B. Modu; B. Herbert

2014-01-01

The Chad basin which covers an area of about 2.4 million kilometer square is one of the largest drainage basins in Africa in the centre of Lake Chad .This basin was formed as a result of rifting and drifting episode, as such it has no outlet to the oceans or seas. It contains large area of desert from the north to the west. The basin covers in part seven countries such as Chad, Nigeria, Central African Republic, Cameroun, Niger, Sudan and Algeria. It is named Chad basin because 43.9%...

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

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.

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

Analysis of 1997–2008 groundwater level changes in the upper Deschutes Basin, Central Oregon

Science.gov (United States)

Gannett, Marshall W.; Lite, Kenneth E.

2013-01-01

Groundwater-level monitoring in the upper Deschutes Basin of central Oregon from 1997 to 2008 shows water-level declines in some places that are larger than might be expected from climate variations alone, raising questions regarding the influence of groundwater pumping, canal lining (which decreases recharge), and other human influences. Between the mid-1990s and mid-2000s, water levels in the central part of the basin near Redmond steadily declined as much as 14 feet. Water levels in the Cascade Range, in contrast, rose more than 20 feet from the mid-1990s to about 2000, and then declined into the mid-2000s, with little or no net change. An existing U.S. Geological Survey regional groundwater-flow model was used to gain insights into groundwater-level changes from 1997 to 2008, and to determine the relative influence of climate, groundwater pumping, and irrigation canal lining on observed water-level trends. To utilize the model, input datasets had to be extended to include post-1997 changes in groundwater pumping, changes in recharge from precipitation, irrigation canal leakage, and deep percolation of applied irrigation water (also known as on-farm loss). Mean annual groundwater recharge from precipitation during the 1999–2008 period was 25 percent less than during the 1979–88 period because of drying climate conditions. This decrease in groundwater recharge is consistent with measured decreases in streamflow and discharge to springs. For example, the mean annual discharge of Fall River, which is a spring-fed stream, decreased 12 percent between the 1979–88 and 1999–2008 periods. Between the mid-1990s and late 2000s, groundwater pumping for public-supply and irrigation uses increased from about 32,500 to 52,000 acre-feet per year, partially because of population growth. Between 1997 and 2008, the rate of recharge from leaking irrigation canals decreased by about 58,000 acre-feet per year as a result of lining and piping of canals. Decreases in recharge

The Messinian evaporites in the Levant Basin: lithology, deformation and its evolution

Science.gov (United States)

Feng, Ye; Steinberg, Josh; Reshef, Moshe

2017-04-01

The lithological composition of the Messinian evaporite in the Levant Basin remains controversial and salt deformation mechanisms are still not fully understood, due to the lack of high resolution 3D depth seismic data and well logs that record the entire evaporite sequence. We demonstrate how 3D Pre-stack depth migration (PSDM) and intra-salt tomography can lead to improved salt imaging. Using 3D PSDM seismic data with great coverage and deepwater well log data from recently drilled boreholes, we reveal intra-salt reflective units associated with thin clastic layers and a seismic transparent background consisting of uniform pure halite. Structural maps of all internal reflectors are generated for stratigraphy and attributes analysis. High amplitude fan structures in the lowermost intra-salt reflector are observed, which may indicate the source of the clastic formation during the Messinian Salinity Crisis (MSC). The Messinian evaporite in the Levant Basin comprises six units; the uppermost unit thickens towards the northwest, whereas the other units are uniform in thickness. The top of salt (TS) horizon is relatively horizontal, while all other intra-salt reflectors and base of salt (BS) dip towards the northwest. Different seismic attributes are used for identification of intra-salt deformation patterns. Maximum curvature maps show NW-striking thrust faults on the TS and upper intra-salt units, and dip azimuth maps are used to show different fold orientations between the TS and intra-salt units, which indicate a two-phase deformation mechanism: basin NW tilting as syn-depositional phase and NNE spreading of Plio-Pleistocene overburden as post-depositional phase. RMS amplitude maps are used to identify a channelized system on the TS. An evaporite evolution model during the MSC of the Levant Basin is therefore established based on all the observations. Finally the mechanical properties of the salts will be utilized to explore salt deformation in the Levant Basin

Physical properties, morphology and petrological characteristics of pumices from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Kalangutkar, N.G.; Iyer, S.D.; Ilangovan, D.

About 400 pumice clasts collected from the Central Indian Ocean Basin (CIOB) were studied for their morphology and classified based on their shape and size. A majority of the samples range between less than 1 cm and 36 cm and in the Zinggs shape...

Interaction between active tectonics, erosion and diapirism, a case study from Habble-Rud in Southern Central Alborz (Northern Iran)

Science.gov (United States)

Jaberi, Maryam; Ghassemi, Mohammad R.; Shayan, Siavosh; Yamani, Mojtaba; Zamanzadeh, Seyed Mohammad

2018-01-01

The Alborz mountain chain is a region of active deformation within the Arabia-Eurasia continental collision zone. The southern part of central Alborz Mountains, in the north of Iran, represents complex tectonics because it is located at the border of two developing continental sedimentary basins between southern central Alborz and Central Iran. An arid and semi-arid climate, a large extent of Quaternary sediments, rugged topography, salt domes and faults with historical seismicity influence the Habble-Rud River catchment. In the present research, a number of tectonic geomorphologic indices were extracted from satellite imagery and 10 m DEM (digital elevation model) data in order to identify relative tectonic activity within the basin. The indices include: stream length-gradient index (Sl), drainage basin asymmetry (Af), index of mountain front sinuosity (Smf), hypsometric integral (Hi), index of drainage basin shape (Bs), ratio of valley-floor width to valley height (Vf), and fault density (Fd). Due to the presence of heterogeneous indices for all sections of the catchment causing large extension of Habble-Rud (3260 km2), all of the variables such as extremely erodible formations, faults and folds and salt tectonics on the Southern part; were put into a matrix table. As a new approach, the variables were put into the SAW (simple additive model) model as one of MADM (multi-attribute decision-making models) techniques. The study area was divided into four regions according to the values of SAW. These classes include very high (%11), high (48.3%), moderate (34.7%), and low activity (3.4%). The result of the model suggests that the study area is located on a changing tectonic trend in central Alborz from NW-SE to NE-SW. The regions with high relative tectonic activity in HR catchment correspond to the active Garmsar and Sorkhe-Kalout faults and diapirs.

Seismic evidence of Messinian salt in opposite margins of West Mediterranean

Science.gov (United States)

Mocnik, Arianna; Camerlenghi, Angelo; Del Ben, Anna; Geletti, Riccardo; Wardell, Nigel; Zgur, Fabrizio

2015-04-01

The post drift Messinian Salinity Crisis (MSC) affected the whole Mediterranean basin, with deposition of evaporitic sequences in the deep basins, in the lower continental slopes, and in several shallower marginal basins; usually, in the continental margins, the MSC originated noticeable erosional truncations that locally cause important hiatuses in the pre-Messinian sequences, covered by the Plio-Quaternary sediments. In this work we focus on the MSC seismic signature of two new seismic datasets acquired in 2010 (West Sardinia offshore) and in 2012 (within the Eurofleet project SALTFLU in the South Balearic continental margin and the northern Algero abyssal plain). The "Messinian trilogy" recognized in the West-Mediterranean abyssal plain, is characterized by different seismic facies: the Lower evaporite Unit (LU), the salt Mobile Unit (MU) and the Upper evaporite mainly gypsiferous Unit (UU). Both seismic datasets show the presence of the Messinian trilogy also if the LU is not always clearly interpretable due to the strong seismic signal absorption by the halite layers; the salt thickness of the MU is similar in both the basins as also the thickness and stratigraphy of the UU. The Upper Unit (UU) is made up of a well reflecting package of about 10 reflectors, partially deformed by salt tectonic and characterized by a thin transparent layer that we interpreted as salt sequence inner the shallower part of the UU. Below the stratified UU, the MU exhibits a transparent layer in the deep basin and also on the foot of the slope, where a negative reflector, related to the high interval velocity of salt, marks its base. The halokinetic processes are not homogeneously distributed in the region, forming a great number of diapirs on the foot of the slope (due to the pression of the slided sediments) and giant domes toward the deep basin (due to the higher thickness of the Plio-quaternary sediments). This distribution seems to be related to the amount of salt and of the

Quantitative radiolarian assemblages in surface sediments from the central Indian Basin and their paleomonsoonal significance

Digital Repository Service at National Institute of Oceanography (India)

Gupta, S.M.

The percentage data of 47 radiolarian coarser taxonomic groups in the surface sediments from the central Indian Basin was subjected to cluster and factor analyses. The R-mode cluster analysis resulted in 3 dominant clusters which represent surface...

Diagenetic remobilization of rare earth elements in a sediment core from the central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Banakar, V.K.

Rare earth elements (REE) distribution in a 36 cm long sediment box core from the Central Indian Basin is studied. REE concentration is generally higher in the upper oxic zone than in intermediate suboxic zone suggesting REE diffusion upwards...

Hydrological and Agricultural Impacts of Climate Change in the Vu Gia-Thu Bon River Basin in Central Vietnam

NARCIS (Netherlands)

Laux, Patrick; Fink, Manfred; Waongo, Moussa; Pedroso, Rui; Salvini, G.; Hoa Tran, Dang; Quang Thinh, Dang; Cullmann, Johannes; Flügel, Wolfgang-Alvert; Kunstmann, H.

2017-01-01

This paper summarizes some of the climate (change) impact modeling activities conducted in the Land useandClimate Changeinteractionsin Central Vietnam (LUCCi)project. The study area is the Vu Gia-Thu Bon (VGTB) river basin in Central Vietnam, which is characterized by recurrent floods during

Floods of November-December 1950 in the Central Valley basin, California

Science.gov (United States)

Paulsen, C.G.

1953-01-01

The flood of November-December 1950 in the Central Valley basin was the greatest in most parts of the basin since the turn of the century and probably was exceeded in the lower San Joaquin River basin only by the historic flood of 1862. In respect to monetary loss, the 1950 flood was the most disastrous in the history of the basin. Loss of life was remarkably small when one considers the extensive damage and destruction to homes and other property, which is estimated at 33 million dollars. Outstanding features of the flood were its unprecedented occurrence so early in the winter flood season, its magnitude in respect to both peak and volume in most major tributaries, and the occurrence of a succession of near-peak flows with a period of three weeks. The flood was caused by a series of storms during the period November 16 to December 8, which brought exceptionally warm, moisture-laden air inland against the Sierra Nevada range and caused intense rainfall, instead of snowfall, at unusually high altitudes. Basin-wide totals of rainfall during the period ranged from 30 inches over the Yuba and American River basins to 13 inches over the upper Sacramento and Feather River basins. Based on continuous records of discharge on major tributaries for periods ranging from 22 to 55 years and averaging about 43 years, the 1950 flood peaks were the greatest of record on the American, Cosumnes, Mokelumne, Stanislaus, Tuolumne, Merced, Chowchilla, Fresno, lower San Joaquin, Kings, Kaweah, Tule, and Kern Rivers. Second highest peak of record occurred during the flood of March 1928 on the Yuba, American and Mokelumne Rivers; the flood of Marcn 1940 on Cosumnes River; the flood of January 1911 on the Stanislaus and Tuolumne Rivers; the flood of December 1937 on the Merced, Kings, and Kaweah Rivers; the flood of March 1938 on the Chowchilla, Fresno, and lower San Joaquin Rivers; and the flood of March 1943 on the Tule and Kern Rivers. Peak discharges for 1950 did not exceed previous

East and central farming and forest region and Atlantic basin diversified farming region: LRRs N and S

Science.gov (United States)

Brad D. Lee; John M. Kabrick

2017-01-01

The central, unglaciated US east of the Great Plains to the Atlantic coast corresponds to the area covered by LRR N (East and Central Farming and Forest Region) and S (Atlantic Basin Diversified Farming Region). These regions roughly correspond to the Interior Highlands, Interior Plains, Appalachian Highlands, and the Northern Coastal Plains.

Relationship between chemical composition and magnetic susceptibility in sediment cores from Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Parthiban, G.; Banakar, V.K.; Tomer, A.; Kulkarni, M.

Three sediment cores in a north–south transect (3 degrees N to 13 degrees S) from different sediment types of the Central Indian Ocean Basin (CIOB) are studied to understand the possible relationship between magnetic susceptibility (Chi) and Al, Fe...

Distribution of baroduric, psychrotrophic and culturable nitrifying and denitrifying bacteria in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

LokaBharathi, P.A.; PradeepRam, A.S.; Nair, S.; Nath, B.N.; Chandramohan, D.

The abundance of baroduric, culturable nitrifying and denitrifying bacteria in the deep-sea cores of Central Indian Basin (CIB) at ca 5000 m depth was investigated. Analysis of 8 cores, sampled between 10 degrees 00 minutes S and 75 degrees 55...

Deposition of Mn-Cu-Ni-enriched sediments during glacial period in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Borole, D.V.

Two siliceous sediment cores collected from the Central Indian Basin have been analysed for organic carbon, biogenic silica, Al, Mn, Ni and Cu content. The concentrations of Mn, Cu and Ni showed one order of magnitude variation (an enrichment by a...

Salt stress induces differential regulation of the phenylpropanoid pathway in Olea europaea cultivars Frantoio (salt-tolerant) and Leccino (salt-sensitive)

NARCIS (Netherlands)

Rossi, Lorenzo; Borghi, Monica; Francini, Alessandra; Lin, Xiuli; Xie, De Yu; Sebastiani, Luca

2016-01-01

Olive tree (Olea europaea L.) is an important crop in the Mediterranean Basin where drought and salinity are two of the main factors affecting plant productivity. Despite several studies have reported different responses of various olive tree cultivars to salt stress, the mechanisms that convey

Geothermal studies of seven interior salt domes

International Nuclear Information System (INIS)

1983-06-01

This report defines and compares the geothermal environments of eight selected Gulf Coast salt domes. The thermal regimes in and around Gulf Coast salt domes are not well documented. The data base used for this study is an accumulation of bottom-hole temperature readings from oil and gas exploration wells and temperature logs run for the National Waste Terminal Storage (NWTS) program. The bottom-hole tempreatures were corrected in order to estimate the actual geothermal environments. Prior thermal studies and models indicate temperatures in and around salt domes are elevated above the norm by 1 0 F to 25 0 F. Using existing geothermal data and accepted theory, geothermal gradients for the selected domes and surrounding sediments were estimated. This study concludes that salt domes within a given basin have similar geothermal gradients, but that the basins differ in average geothermal gradients. This relationship is probably controlled by deep basement structural trends. No evidence of residual heat of emplacement was found associated with any of the selected domes

Ethiopian Central Rift Valley basin hydrologic modelling using HEC-HMS and ArcSWAT

Science.gov (United States)

Pascual-Ferrer, Jordi; Candela, Lucila; Pérez-Foguet, Agustí

2013-04-01

An Integrated Water Resources Management (IWRM) shall be applied to achieve a sustainable development, to increase population incomes without affecting lives of those who are highly dependent on the environment. First step should be to understand water dynamics at basin level, starting by modeling the basin water resources. For model implementation, a large number of data and parameters are required, but those are not always available, especially in some developing countries where different sources may have different data, there is lack of information on data collection, etc. The Ethiopian Central Rift Valley (CRV) is an endorheic basin covering an area of approximately 10,000 km2. For the period 1996-2005, the average annual volume of rainfall accounted for 9.1 Mm3, and evapotranspiration for 8 Mm3 (Jansen et al., 2007). From the environmental point of view, basin ecosystems are endangered due to human activities. Also, poverty is widespread all over the basin, with population mainly living from agriculture on a subsistence economy. Hence, there is an urgent need to set an IWRM, but datasets required for water dynamics simulation are not too reliable. In order to reduce uncertainty of numerical simulation, two semi-distributed open software hydrologic models were implemented: HEC-HMS and ArcSWAT. HEC-HMS was developed by the United States Army Corps of Engineers (USACoE) Hydrologic Engineering Center (HEC) to run precipitation-runoff simulations for a variety of applications in dendritic watershed systems. ArcSWAT includes the SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) model developed for the USDA Agricultural Research Service into ArcGIS (ESRI®). SWAT was developed to assess the impact of land management practices on large complex watersheds with varying soils, land use and management conditions over long periods of time (Neitsch et al., 2005). According to this, ArcSWAT would be the best option for IWRM implementation in the basin. However

Kinematics and dynamics of salt movement driven by sub-salt normal faulting and supra-salt sediment accumulation - combined analogue experiments and analytical calculations

Science.gov (United States)

Warsitzka, Michael; Kukowski, Nina; Kley, Jonas

2017-04-01

In extensional sedimentary basins, the movement of ductile salt is mainly controlled by the vertical displacement of the salt layer, differential loading due to syn-kinematic deposition, and tectonic shearing at the top and the base of the salt layer. During basement normal faulting, salt either tends to flow downward to the basin centre driven by its own weight or it is squeezed upward due to differential loading. In analogue experiments and analytical models, we address the interplay between normal faulting of the sub-salt basement, compaction and density inversion of the supra-salt cover and the kinematic response of the ductile salt layer. The analogue experiments consist of a ductile substratum (silicone putty) beneath a denser cover layer (sand mixture). Both layers are displaced by normal faults mimicked through a downward moving block within the rigid base of the experimental apparatus and the resulting flow patterns in the ductile layer are monitored and analysed. In the computational models using an analytical approximative solution of the Navier-Stokes equation, the steady-state flow velocity in an idealized natural salt layer is calculated in order to evaluate how flow patterns observed in the analogue experiments can be translated to nature. The analytical calculations provide estimations of the prevailing direction and velocity of salt flow above a sub-salt normal fault. The results of both modelling approaches show that under most geological conditions salt moves downwards to the hanging wall side as long as vertical offset and compaction of the cover layer are small. As soon as an effective average density of the cover is exceeded, the direction of the flow velocity reverses and the viscous material is squeezed towards the elevated footwall side. The analytical models reveal that upward flow occurs even if the average density of the overburden does not exceed the density of salt. By testing various scenarios with different layer thicknesses

Preliminary analyses of scenarios for potential human interference for repositories in three salt formations

International Nuclear Information System (INIS)

1985-10-01

Preliminary analyses of scenarios for human interference with the performance of a radioactive waste repository in a deep salt formation are presented. The following scenarios are analyzed: (1) the U-Tube Connection Scenario involving multiple connections between the repository and the overlying aquifer system; (2) the Single Borehole Intrusion Scenario involving penetration of the repository by an exploratory borehole that simultaneously connects the repository with overlying and underlying aquifers; and (3) the Pressure Release Scenario involving inflow of water to saturate any void space in the repository prior to creep closure with subsequent release under near lithostatic pressures following creep closure. The methodology to evaluate repository performance in these scenarios is described and this methodology is applied to reference systems in three candidate formations: bedded salt in the Palo Duro Basin, Texas; bedded salt in the Paradox Basin, Utah; and the Richton Salt Dome, Mississippi, of the Gulf Coast Salt Dome Basin

Some new observations on the intra-plate deformation in the Central Indian Basin (CIB)

Digital Repository Service at National Institute of Oceanography (India)

Murthy, K.S.R.; Neprochnov, O.V.; Levchenko, O.V.; Rao, T.C.S.; Milanovsky, V.E.; Lakshminarayana, S.

IN THE CENTRAL INDIAN BASIN 191 , , i ,//" N 1 1~,,,,'-,~- x....~-,..-v--- - - ,..,~/~_. oo I -- ,9 .... 2~. ----" 0 i'" 1 o 8;:50' 8400'E 84-,I0' la I ,__ j; -t ool lOS \\/, .~ -v., .~ ! jF/.~lrt.,/ I I l ~i "°7 ~ o~ o - - ioTaS?-%- -i -h--A~'~-~'~, -/I...

On the representation of regional characteristics by hydrographic measurements at central stations in four deep basins of the Baltic Sea

Directory of Open Access Journals (Sweden)

J. H. Reissmann

2006-01-01

Full Text Available In this work the eddy resolving data sets of salinity, temperature, and oxygen content aquired in the framework of the German-Russian project MESODYN (MESOscale DYNamics in the Arkona Basin, the Bornholm Basin, the Stolpe Furrow, and the Eastern Gotland Basin during summer and winter stratification situations are utilized to examine to which extent the observations at the central monitoring stations within these basins are representative for the spatial mean state of the corresponding region with respect to comparative monitoring purposes of the whole Baltic Sea. The investigation covers profiles of salinity, potential temperature, oxygen content, potential density, and squared buoyancy or Brunt-Väisälä frequency. Moreover, some parameters of the halocline, namely its depth, thickness, and upper and lower boundaries, and the first baroclinic Rossby radii are subject to the investigation. The profiles match best for the squared buoyancy or Brunt-Väisälä frequency. The profiles of salinity match best in the Eastern Gotland Basin and worst in the Arkona Basin both for summer and winter stratification situations. The overall agreement for the halocline parameters is good. The baroclinic Rossby radii match their spatial mean values well, if the depth range considered for their calculation is restricted to the mean depth in each region at the bottom side. In doing so they also match the spatial mean values of the first baroclinic Rossby radii calculated considering the whole depth range at each station. Overall, the regional characteristics of the investigated quantities and parameters are represented well by the hydrographic measurements at the central stations in the four regions in spite of some significant differences between the spatial mean states and the observations at the central stations. In particular, the observations at the central stations seem to be usefull for comparisons between these regions. However, the observed differences

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

Digital Repository Service at National Institute of Oceanography (India)

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

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

Salt exploitation in the later prehistory of the Carpathian Basin

Directory of Open Access Journals (Sweden)

Anthony Harding

2015-12-01

Full Text Available Salt is a necessity for humans and animals, today as in the ancient past. The ways in which salt was produced in ancient times vary from area to area, and could use briquetage, deep mining (as at Hallstatt, or the technique specific to Transylvania, based on wooden troughs, perforated in the base. How these troughs functioned is still uncertain. In the Iron Age a different technique was employed, involving deep shafts dug down to the rock salt surface. As well as technological considerations, it is crucial to understand the social and economic importance of salt in the ancient world.

Effect of road salt application on seasonal chloride concentrations and toxicity in south-central Indiana streams.

Science.gov (United States)

Gardner, Kristin M; Royer, Todd V

2010-01-01

Contemporary information on road salt runoff is needed for management of water resources in regions experiencing urbanization and increased road density. We investigated seasonal Cl(-) concentrations among five streams in south-central Indiana that drained watersheds varying in degree of urbanization and ranging in size from 9.3 to 27 km(2). We also conducted acute toxicity tests with Daphnia pulex to assess the potential effects of the observed Cl(-) concentrations on aquatic life. Periods of elevated Cl(-) concentrations were observed during the winters of 2007-08 and 2008-09 at all sites except the reference site. The highest Cl(-) concentration observed during the study was 2100 mg L(-1) and occurred at the most urbanized site. The Cl(-) concentration at the reference site never exceeded 22 mg L(-1). The application of road salt caused large increases in stream Cl(-) concentrations, but the elevated Cl(-) levels did not appear to be a significant threat to aquatic life based on our toxicity testing. Only the most urbanized site showed evidence of salt retention within the watershed, whereas the other sites exported the road salt relatively quickly after its application, suggesting storm drains and impervious surfaces minimized interaction between soils and salt-laden runoff. During winter at these sites, the response in stream Cl(-) concentrations appeared to be controlled by the timing and intensity of road salt application, the magnitude of precipitation, and the occurrence of air temperatures that caused snowmelt and generated runoff.

Non-volant mammals in a protected area on the Central Andes of Colombia: new records for the Caldas department and the Chinchiná River basin

OpenAIRE

Ramírez-Mejía, Andrés; Sánchez, Francisco

2015-01-01

The Chinchiná River basin is located on the western slope of the Colombian Central Andes. This basin provides ecosystem services such as water provision for >500,000 people, but has suffered considerable ecosystem degradation, and the information on its biodiversity is limited. We inventoried the non-volant mammals in the Caldas' Central Hydroelectric (CHEC) Reserve in the Chinchiná River basin, in the Caldas department. We detected 18 species of mammals, present the first record of Puma ya...

Zechstein salt Denmark. Vol. 1

International Nuclear Information System (INIS)

Lyngsie Jacobsen, F.; Soenderholm, M.; Springer, N.; Gutzon Larsen, J.; Lagoni, P.; Fabricius, J.

1984-01-01

The Salt Research Project EFP-81 has mainly been aiming upon an elucidation of the stratigraphy of the Danish Zechstein evaporites. Also an attempt to clarify the connection between the fabric and the strength of the strongly deformed domal rock salt is performed. The unravelling of the stratigraphy is carried out by means of renewed interpretations of new and old data from all the wells drilling in the Danish Permian basin in connection with a revaluation of the core descriptions. By means of trace elements analysis it is possible to some extent to distinguish between Zestein 1 and 2 ''grey salt''. A description of the transition zone between Zechstein 1 and 2 is carried out. New methods of fabric analyses are introduced and the strength measurements of the rock salt are treated statistically in connection with new defined rock salt parameters. An investigation of fluid inclusions in halite and quartz crystals from dome salt has resulted in the determination of salinity and chemical composition of the brines present in the salt. Temperatures and corresponding pressures during the evolution of the salt pillow and salt dome have been established. The dehydration conditions of natural carnallite in situ are clarified. (author)

Assessing groundwater recharge in an Andean closed basin using isotopic characterization and a rainfall-runoff model: Salar del Huasco basin, Chile

Science.gov (United States)

Uribe, Javier; Muñoz, José F.; Gironás, Jorge; Oyarzún, Ricardo; Aguirre, Evelyn; Aravena, Ramón

2015-11-01

Closed basins are catchments whose drainage networks converge to lakes, salt flats or alluvial plains. Salt flats in the closed basins in arid northern Chile are extremely important ecological niches. The Salar del Huasco, one of these salt flats located in the high plateau (Altiplano), is a Ramsar site located in a national park and is composed of a wetland ecosystem rich in biodiversity. The proper management of the groundwater, which is essential for the wetland function, requires accurate estimates of recharge in the Salar del Huasco basin. This study quantifies the spatio-temporal distribution of the recharge, through combined use of isotopic characterization of the different components of the water cycle and a rainfall-runoff model. The use of both methodologies aids the understanding of hydrological behavior of the basin and enabled estimation of a long-term average recharge of 22 mm/yr (i.e., 15 % of the annual rainfall). Recharge has a high spatial variability, controlled by the geological and hydrometeorological characteristics of the basin, and a high interannual variability, with values ranging from 18 to 26 mm/yr. The isotopic approach allowed not only the definition of the conceptual model used in the hydrological model, but also eliminated the possibility of a hydrogeological connection between the aquifer of the Salar del Huasco basin and the aquifer that feeds the springs of the nearby town of Pica. This potential connection has been an issue of great interest to agriculture and tourism activities in the region.

Area geological characterization report for the Palo Duro and Dalhart Basins, Texas

International Nuclear Information System (INIS)

1983-07-01

The present state of knowledge of the geology, hydrogeology, and seismology of the Palo Duro and Dalhart basins is summarized as a basis for future siting studies for a high-level nuclear waste repository. Large portions of the Texas Panhandle, and especially the Palo Duro basin, have stable geologic conditions and a favorable evaporite stratigraphy that warrant further study. Five salt-bearing formations containing thick salt units are present within the basin. Salt beds appear to be persistent over wide areas, relatively flat lying and structurally undisturbed. Available hydrogeologic data suggest that favorable conditions for waste isolation are widespread. The level and rate of seismic activity are low throughout the Texas Panhandle. 335 references, 83 figures, 17 tables

Chemical characteristics of Central Indian Basin waters during the southern summer

Digital Repository Service at National Institute of Oceanography (India)

DeSousa, S.N.; Sardessai, S.; RameshBabu, V.; Murty, V.S.N.; Gupta, G.V.M.

aspects of oxygen deficient conditions and denitrification in the Arabian Sea. Journal of MarineResearch 45,1049–1072. Redfield,A.C.,Ketchum,B.H.,Richards,F.A.,1963.Theinfluenceoforganismsonthecompositionofseawater.In: Hill, M.N. (Ed.), The Sea: Ideas...-Sea Research II 48 (2001)3343–3352 Chemical characteristics of Central Indian Basin waters during the southern summer S.N. de Sousa*,S.D. Sardessai, V. Ramesh Babu, V.S.N. Murty, G.V.M. Gupta NationalInstituteofOceanography,DonaPaula,Goa403004,India Abstract...

Paleozoic evolution of active margin basins in the southern Central Andes (northwestern Argentina and northern Chile)

Science.gov (United States)

Bahlburg, H.; Breitkreuz, C.

The geodynamic evolution of the Paleozoic continental margin of Gondwana in the region of the southern Central Andes is characterized by the westward progression of orogenic basin formation through time. The Ordovician basin in the northwest Argentinian Cordillera Oriental and Puna originated as an Early Ordovician back-arc basin. The contemporaneous magmatic arc of an east-dipping subduction zone was presumably located in northern Chile. In the back-arc basin, a ca. 3500 meter, fining-up volcaniclastic apron connected to the arc formed during the Arenigian. Increased subsidence in the late Arenigian allowed for the accomodation of large volumes of volcaniclastic turbidites during the Middle Ordovician. Subsidence and sedimentation were caused by the onset of collision between the para-autochthonous Arequipa Massif Terrane (AMT) and the South American margin at the Arenigian-Llanvirnian transition. This led to eastward thrusting of the arc complex over its back-arc basin and, consequently, to its transformation into a marine foreland basin. As a result of thrusting in the west, a flexural bulge formed in the east, leading to uplift and emergence of the Cordillera Oriental shelf during the Guandacol Event at the Arenigian-Llanvirnian transition. The basin fill was folded during the terminal collision of the AMT during the Oclóyic Orogeny (Ashgillian). The folded strata were intruded post-tectonically by the presumably Silurian granitoids of the "Faja Eruptiva de la Puna Oriental." The orogeny led to the formation of the positive area of the Arco Puneño. West of the Arco Puneño, a further marine basin developed during the Early Devonian, the eastern shelf of which occupied the area of the Cordillera Occidental, Depresión Preandina, and Precordillera. The corresponding deep marine turbidite basin was located in the region of the Cordillera de la Costa. Deposition continued until the basin fill was folded in the early Late Carboniferous Toco Orogeny. The basin

Behavior of rare earth elements in coexisting manganese macronodules, micronodules, and sediments from the central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Colley, S.; Higgs, N.C.

Associated manganese macronodules, micronodules, and sediments from the Central Indian Basin (CIB) were analyzed for major, trace, and rare earth elements (REE) to understand REE carrier phases and their fractionation pattern among three...

Variation in size, morphology and chemical composition of polymetallic nodules from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Valsangkar, A.B.; Karisiddaiah, S.M.; Parthiban, G.

Chemical composition of 613 polymetallic nodules from 150 stations in the Central Indian Ocean Basin (CIOB) are determined and variations in Mn, Fe, Cu, Ni, Co, Zn and moisture content are studied with respect to their size and surface texture...

A history of salt.

Science.gov (United States)

Cirillo, M; Capasso, G; Di Leo, V A; De Santo, N G

1994-01-01

The medical history of salt begins in ancient times and is closely related to different aspects of human history. Salt may be extracted from sea water, mineral deposits, surface encrustations, saline lakes and brine springs. In many inland areas, wood was used as a fuel source for evaporation of brine and this practice led to major deafforestation in central Europe. Salt played a central role in the economies of many regions, and is often reflected in place names. Salt was also used as a basis for population censuses and taxation, and salt monopolies were practised in many states. Salt was sometimes implicated in the outbreak of conflict, e.g. the French Revolution and the Indian War of Independence. Salt has also been invested with many cultural and religious meanings, from the ancient Egyptians to the Middle Ages. Man's innate appetite for salt may be related to his evolution from predominantly vegetarian anthropoids, and it is noteworthy that those people who live mainly on protein and milk or who drink salty water do not generally salt their food, whereas those who live mainly on vegetables, rice and cereals use much more salt. Medicinal use tended to emphasize the positive aspects of salt, e.g. prevention of putrefaction, reduction of tissue swelling, treatment of diarrhea. Evidence was also available to ancient peoples of its relationship to fertility, particularly in domestic animals. The history of salt thus represents a unique example for studying the impact of a widely used dietary substance on different important aspects of man's life, including medical philosophy.

Magnetic and bathymetric studies in the vicinity of the 73 degree E fracture zone, Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

KameshRaju, K.A.

Ridges. The re- construction studies of Patriat and Segoufin The Central Indian Basin, located between (1988) provided a synthesis of the magnetic the Central Indian Ridge and the Ninety East data from these three ridges. In addition, de- Ridge... by Royer and 16" 30' S; a profile recently collected along 71 * E Schlich (1988) have enhanced our under- was also studied. Figure 1 shows the study area standing of the evolution of the Indian Ocean and the major tectonic features in the Central...

Paleomagnetic and chronostratigraphic constraints on the Middle to Late Miocene evolution of the Transylvanian Basin (Romania): Implications for Central Paratethys stratigraphy and emplacement of the Tisza-Dacia plate

Science.gov (United States)

de Leeuw, Arjan; Filipescu, Sorin; Maţenco, Liviu; Krijgsman, Wout; Kuiper, Klaudia; Stoica, Marius

2013-04-01

constrained between the first occurrence (FO) of Orbulina suturalis at 14.56 Ma and 14.38 ± 0.06 Ma. During the subsequent Badenian Salinity Crisis (BSC) up to 300 m of salt accumulate in the basin center. The faunal turnover that marks the Badenian-Sarmatian Boundary is dated at 12.80 ± 0.05 Ma. A second phase of intense volcanism occurs at 12.4 Ma and leads to deposition of the middle Sarmatian tuff complex (Ghiriş, Hădăreni, Turda and Câmpia Turzii tuffs). Rates of sediment accumulation strongly diminish in the basin center at the onset of the Pannonian stage coincident with an approximately 20° CW tectonic rotation of the Tisza-Dacia plate. Concurrent enhanced uplift in the Eastern a'nd Southern Carpathians leads to the isolation of the Central Paratethys and triggers the transition from marine to freshwater conditions. An additional Pannonian to post-Pannonian 6° of CW rotation is related to the creation of antiform geometries in the Eastern Carpathians which are notably larger in the north than in the south. An 8.4 Ma age is determined for the uppermost Pannonian sediments preserved in the central part of the Transylvanian Basin. Two sections belonging to middle Pannonian Zone D, and the lower part of Zone E (Subzone E1) are found to cover the 10.6-9.9 Ma time-interval.

Structural control of the basement in the central portion of the Santos Basin-Brazil; Controle estrutural do embasamento na porcao central da Bacia de Santos

Energy Technology Data Exchange (ETDEWEB)

Izeli, Maira G.B.; Morales, Norberto; Souza, Iata A. de [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas

2008-07-01

New discoveries of oil in deep water and ultra-deep water in Santos Basin suggest that it needs to be studied to better understanding of basement structures and their role in the basin control and configuration. This study characterizes the main tectonic structures of a portion at the central area of this basin, looking for their relation to the geological basement framework. The study is based on the integration of the geological and geophysical data from subsurface (offshore) and surface of the adjacent continent. These analyses include the continental structures that continue in direction of this basin (Guapiara Lineament and Ponta Grossa Arc), checking their possible influence on the basin evolution and deformation. To achieve the proposed goals, the Precambrian basement lineaments were extracted from the offshore area using remote sensing, as result was obtained strong NW-SE structural trend. According to the interpretation of seismic sections, it is possible to observe that this portion of the basin presents main NE-SW structural trend, and most of the structures are typical of passive margin and halokintics process. It is possible to see that some recognized faults in the rift deposits may be coinciding with the main continental guidelines which are projected into the basin. (author)

Characterization of PM10 sources in the central Mediterranean

Science.gov (United States)

Calzolai, G.; Nava, S.; Lucarelli, F.; Chiari, M.; Giannoni, M.; Becagli, S.; Traversi, R.; Marconi, M.; Frosini, D.; Severi, M.; Udisti, R.; di Sarra, A.; Pace, G.; Meloni, D.; Bommarito, C.; Monteleone, F.; Anello, F.; Sferlazzo, D. M.

2015-12-01

The Mediterranean Basin atmosphere is influenced by both strong natural and anthropogenic aerosol emissions and is also subject to important climatic forcings. Several programs have addressed the study of the Mediterranean basin; nevertheless important pieces of information are still missing. In this framework, PM10 samples were collected on a daily basis on the island of Lampedusa (35.5° N, 12.6° E; 45 m a.s.l.), which is far from continental pollution sources (the nearest coast, in Tunisia, is more than 100 km away). After mass gravimetric measurements, different portions of the samples were analyzed to determine the ionic content by ion chromatography (IC), the soluble metals by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the total (soluble + insoluble) elemental composition by particle-induced x-ray emission (PIXE). Data from 2007 and 2008 are used in this study. The Positive Matrix Factorization (PMF) model was applied to the 2-year long data set of PM10 mass concentration and chemical composition to assess the aerosol sources affecting the central Mediterranean basin. Seven sources were resolved: sea salt, mineral dust, biogenic emissions, primary particulate ship emissions, secondary sulfate, secondary nitrate, and combustion emissions. Source contributions to the total PM10 mass were estimated to be about 40 % for sea salt, around 25 % for mineral dust, 10 % each for secondary nitrate and secondary sulfate, and 5 % each for primary particulate ship emissions, biogenic emissions, and combustion emissions. Large variations in absolute and relative contributions are found and appear to depend on the season and on transport episodes. In addition, the secondary sulfate due to ship emissions was estimated and found to contribute by about one-third to the total sulfate mass. Results for the sea-salt and mineral dust sources were compared with estimates of the same contributions obtained from independent approaches, leading to an

Hydrothermal dolomite reservoir facies in the Sinian Dengying Fm, central Sichuan Basin

Directory of Open Access Journals (Sweden)

Yuqiang Jiang

2017-07-01

Full Text Available The Upper Sinian Dengying Fm is the focus of natural gas exploration in the central part of the Sichuan Basin (central Sichuan Basin in recent years. Especially, epigenic karstification and its resulted reservoir-seepage spaces have always been the focal points in researches. Based on the petrographic characteristics of drilling cuttings and core samples, and through experimental analysis by using trace elements, isotopes, and cathodoluminescence, the Dengying Fm dolomite was demonstrated to have matrix recrystallized dolomite (MRD, filled saddle dolomite (FSD (the mean homogenization temperature of inclusion: 178.5 °C, high concentrations of Fe & Mn, slightly positive 87Sr/86Sr value and hydrothermal minerals combination (including sphalerite, galena, pyrite, and quartz, etc.. Thus, it was proposed that hydrothermal dolomite reservoir facies (HDRF exist in the Dengying Fm dolomite, in other words, the dolomite reservoir is composed of hydrothermal dissolved pores, intercrystalline pores of hydrothermal origin, hydrothermal caverns and expanded fractures, and was formed due to the reworking of hydrothermal fluid on tight matrix dolomite. Identification marks are presented in terms of petrography and geochemistry so that hydrothermal dolomite reservoir facies can be effectively recognized and identified. It is concluded that the development of hydrothermal dolomite reservoir facies in this area are preliminary controlled by deep and large basement faults and the strength of hydrothermal fluids.

Diagnosis and Management of Combined Central Diabetes Insipidus and Cerebral Salt Wasting Syndrome After Traumatic Brain Injury.

Science.gov (United States)

Wu, Xuehai; Zhou, Xiaolan; Gao, Liang; Wu, Xing; Fei, Li; Mao, Ying; Hu, Jin; Zhou, Liangfu

2016-04-01

Combined central diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury (TBI) is rare, is characterized by massive polyuria leading to severe water and electrolyte disturbances, and usually is associated with very high mortality mainly as a result of delayed diagnosis and improper management. We retrospectively reviewed the clinical presentation, management, and outcomes of 11 patients who developed combined central diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury to define distinctive features for timely diagnosis and proper management. The most typical clinical presentation was massive polyuria (10,000 mL/24 hours or >1000 mL/hour) refractory to vasopressin alone but responsive to vasopressin plus cortisone acetate. Other characteristic presentations included low central venous pressure, high brain natriuretic peptide precursor level without cardiac dysfunction, high 24-hour urine sodium excretion and hypovolemia, and much higher urine than serum osmolarity; normal serum sodium level and urine specific gravity can also be present. Timely and adequate infusion of sodium chloride was key in treatment. Of 11 patients, 5 had a good prognosis 3 months later (Extended Glasgow Outcome Scale score ≥6), 1 had an Extended Glasgow Outcome Scale score of 4, 2 died in the hospital of brain hernia, and 3 developed a vegetative state. For combined diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury, massive polyuria is a major typical presentation, and intensive monitoring of fluid and sodium status is key for timely diagnosis. To achieve a favorable outcome, proper sodium chloride supplementation and cortisone acetate and vasopressin coadministration are key. Copyright © 2016 Elsevier Inc. All rights reserved.

Ferromanganese nodules and their associated sediments from the Central Indian Ocean Basin: Rare earth element geochemistry

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Rao, Ch.M.; Migdisov, A.A.; Colley, S.; Higgs, N.C.; Demidenko, L.

FerromanganeseNodulesandtheirAssociatedSedimentsfromtheCentralIndianOceanBasin:RareEarthElementGeochemistry J.N.PATTANCH.M.RAONationalInstituteofOceanography,DonaPaula Goa,IndiaA.A.MIGDISOV InstituteofGeochemistry,RussianAcademyofSciencesMoscow,Russia S.COLLEY,N.C.HIGGSSouthamptonOceanographyCentre,EmpressDockSouthampton...

Discussion on the genesis and mineralization of sandstone type uranium deposit in the southern-central Longchuanjiang basin, western Yunnan province

International Nuclear Information System (INIS)

Cai Yuqi; Li Mangen

2002-01-01

The author mainly discusses the character of the depositional systems, geological structures and ore-bearing series in the south-central Longchuanjiang basin, and points out that the uranium mineralization is closely related to the two depositional discontinuities caused by the tectonic evolution. Based on the characteristics of uranium mineralization in the area, pitchblende, uranium blacks and phosphuranylite are discovered in No. 382 uranium deposit and radiometric super-micro-minerals in No. 381 deposit. The research on the uranium mineralization age in No. 382 deposit shows that the mineralization in the south-central part of the basin has genetically multi-staged

Dissolved organic carbon in the INDEX area of the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Sardessai, S.; De

-Sea Research II 48 (2001) 3353–3361 Dissolved organic carbon in the INDEX area of the Central Indian Basin Sugandha Sardessai*, S.N. de Sousa National Institute of Oceanography, Dona-Paula, Goa 403 004, India Abstract Dissolved organic carbon (DOC..., 1996). While there is substantial information available on the DOC content of sea water throughout the Atlantic, Pacific and southern oceans, there are limited reports on contents and distribution of this organic fraction in the Indian Ocean (Menzel...

Climate change adaptation in a highly urbanized snowmelt dominated basin in Central Chile

Science.gov (United States)

Vicuna, S.; Bustos, E.; Merino, P.; Henriquez Dole, L. E.; Jansen, S.; Gil, M.; Ocampo, A.; Poblete, D.; Tosoni, D.; Meza, F. J.; Donoso, G.; Melo, O.

2015-12-01

The Maipo river basin holds 40% of Chile's total population and produces almost half of the country's Gross Domestic Product. The basin is located in the semiarid and snowmelt dominated central region of the country and, aside from the typical pressures of growth in developing country basins, the Maipo river basin faces climate change impacts associated with a reduction in total runoff and changes in its seasonality. Surface water is the main water source for human settlements, natural ecosystems, and economic activities including agriculture, mining and hydropower production. In 2012 a research project, called MAPA (Maipo Plan de Adaptacion), began with the objective of articulating a climate variability and climate change adaptation plan for the Maipo river basin. The project engaged at the beginning a group of relevant water and land use stakeholders which allowed for a good representation of critical aspects of an adaptation plan such as the definition of objectives and performance indicators, future land use scenarios, modeling of the different components of the system and design of adaptation strategies. The presentation will highlight the main results of the research project with a special focus on the upper catchments of the basin. These results include the assessment of impacts associated with future climate and land use scenarios on key components of the hydrologic cycle including snowmelt and glacier contribution to runoff and subsequent impacts on water availability for the operation of hydropower facilities, satisfaction of instream (recreation and aquatic ecosystem) uses and provision of water for the city of Santiago (7 million people) and to irrigate more than 100,000 hectares of high value crops. The integrative approach followed in this project including different perspectives on the use of water in the basin provides a good opportunity to test the varying degree of impacts that could be associated with a given future scenario and also understand

Possible salt mine and brined cavity sites for radioactive waste disposal in the northeastern southern peninsula of Michigan

International Nuclear Information System (INIS)

Landes, K.K.; Bourne, H.L.

1976-01-01

A reconnaissance report on the possibilities for disposal of radioactive waste covers Michigan only, and is more detailed than an earlier one involving the northeastern states. Revised ''ground rules'' for pinpointing both mine and dissolved salt cavern sites for waste disposal include environmental, geologic, and economic factors. The Michigan basin is a structural bowl of Paleozoic sediments resting on downwarped Precambrian rocks. The center of the bowl is in Clare and Gladwin Counties, a short distance north of the middle of the Southern Peninsula. The strata dip toward this central area, and some stratigraphic sequences, including especially the salt-containing Silurian section, increase considerably in thickness in that direction. Lesser amounts of salt are also present in the north central part of the Lower Peninsula. Michigan has been an oil and gas producing state since 1925 and widespread exploration has had two effects on the selection of waste disposal sites: (1) large areas are leased for oil and gas; and (2) the borehole concentrations, whether producing wells, dry holes, or industrial brine wells that penetrated the salt section, should be avoided. Two types of nuclear waste, low level and high level, can be stored in man-made openings in salt beds. The storage facilities are created by (1) the development of salt mines where the depths are less than 3000 ft, and (2) cavities produced by pumping water into a salt bed, and bringing brine back out. The high level waste disposal must be confined to mines of limited depth, but the low level wastes can be accommodated in brine cavities at any depth. Seven potential prospects have been investigated and are described in detail

Regional subsidence history and 3D visualization with MATLAB of the Vienna Basin, central Europe

Science.gov (United States)

Lee, E.; Novotny, J.; Wagreich, M.

2013-12-01

This study reconstructed the subsidence history by the backstripping and 3D visualization techniques, to understand tectonic evolution of the Neogene Vienna Basin. The backstripping removes the compaction effect of sediment loading and quantifies the tectonic subsidence. The amount of decompaction was calculated by porosity-depth relationships evaluated from seismic velocity data acquired from two boreholes. About 100 wells have been investigated to quantify the subsidence history of the Vienna Basin. The wells have been sorted into 10 groups; N1-4 in the northern part, C1-4 in the central part and L1-2 in the northernmost and easternmost parts, based on their position within the same block bordered by major faults. To visualize 3D subsidence maps, the wells were arranged to a set of 3D points based on their map location (x, y) and depths (z1, z2, z3 ...). The division of the stratigraphic column and age range was arranged based on the Central Paratethys regional Stages. In this study, MATLAB, a numerical computing environment, was used to calculate the TPS interpolation function. The Thin-Plate Spline (TPS) can be employed to reconstruct a smooth surface from a set of 3D points. The basic physical model of the TPS is based on the bending behavior of a thin metal sheet that is constrained only by a sparse set of fixed points. In the Lower Miocene, 3D subsidence maps show strong evidence that the pre-Neogene basement of the Vienna Basin was subsiding along borders of the Alpine-Carpathian nappes. This subsidence event is represented by a piggy-back basin developed on top of the NW-ward moving thrust sheets. In the late Lower Miocene, Group C and N display a typical subsidence pattern for the pull-apart basin with a very high subsidence event (0.2 - 1.0 km/Ma). After the event, Group N shows remarkably decreasing subsidence, following the thin-skinned extension which was regarded as the extension model of the Vienna Basin in the literature. But the subsidence in

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

Contrast in manganese nodule distribution on either side of 79~'E fracture zone in central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Kodagali, V.N.

Seabed topography is one of the prime factors in controlling the distribution of manganese nodules. Study of the nodule abundance on either side of the 79~'E fracture zone in the Central Indian Basin (idenfitied from multibeam bathymetric data...

Paleogene ichthyoliths from the substrates of ferromanganese encrustations and nuclei of manganese nodules from the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Gupta, S.M.

Ichthyoliths, the phosphatic microscopic skeletal debris of the fishes are found in the substrates and the nuclei of ferromanganese encrustations and the nodules collected from the Central Indian Ocean Basin. About thirty subtypes...

INTEGRATING GEOPHYSICS, GEOLOGY, AND HYDROLOGY TO DETERMINE BEDROCK GEOMETRY CONTROLS ON THE ORIGIN OF ISOLATED MEADOW COMPLEXES WITHIN THE CENTRAL GREAT BASIN, NEVADA

Science.gov (United States)

Riparian meadow complexes found in mountain ranges of the Central Great Basin physiographic region (western United States) are of interest to researchers as they contain significant biodiversity relative to the surrounding basin areas. These meadow complexes are currently degradi...

Influence of inherited structures on the growth of basement-cored ranges, basin inversion and foreland basin development in the Central Andes, from apatite fission-track and apatite Helium thermochronology.

Science.gov (United States)

Zapata, S.; Sobel, E. R.; Del Papa, C.; Jelinek, A. R.; Muruaga, C.

2017-12-01

The Central Andes in NW of Argentina is part of a long-lived subduction zone, active since the Paleozoic. This region experienced several tectonic cycles; each of which created an unique set of structures and may have reactivated preexisting structures. These inherited structures may exert a first-order control over the different foreland deformational styles observed along the strike in the Central Andes. Our study area is located between 26°S and 28°S on the transition between the broken foreland (Santa Barbara system), which expresses a combination of thin-skin and thick-skin styles, and the Sierras Pampeanas, which is deform in a thick-skin style. The Cumbres Calchaquies range and the associated Choromoro Basin are located in the northern part of the study area, and are the southern expression of the Santa Barbara system. Published thermochronology data suggest that the rocks from the basement experienced Late Cretaceous and Late Miocene exhumation; the associated sedimentary rocks within the Choromoro basin experienced Paleogene and Late Miocene deformational phases. In contrast, the Sierra Aconquija range, located immediately south on the transition to the Sierras Pampeanas (thick skin) foreland basin, exhibit larger amounts of Miocene exhumation and lack of Cretaceous exhumation; the associated sedimentary rocks from the Tucuman basin have not been deformed since the Cretaceous. Our goal is to understand the evolution of the structural blocks and the structures responsible for the along strike changes in foreland basin deformational styles and their relation with inherited structures from previous tectonic cycles. We are obtaining new apatite U-Th/He and fission track data to reconstruct the thermal history of the basement, accompanied by U-Pb geochronology and stratigraphy to constrain the evolution of the associated sedimentary basins. Preliminary results combined with published data suggest that inherited structures within the study area have evolved

Uranium favorability of the San Rafael Swell area, east-central Utah

International Nuclear Information System (INIS)

Mickle, D.G.; Jones, C.A.; Gallagher, G.L.; Young, P.; Dubyk, W.S.

1977-10-01

The San Rafael Swell project area in east-central Utah is approximately 3,000 sq mi and includes the San Rafael Swell anticline and the northern part of the Waterpocket Fold monocline at Capitol Reef. Rocks in the area are predominantly sedimentary rocks of Pennsylvanian through Cretaceous age. Important deposits of uranium in the project area are restricted to two formations, the Chinle (Triassic) and Morrison (Jurassic) Formations. A third formation, the White Rim Sandstone (Permian), was also studied because of reported exploration activity. The White Rim Sandstone is considered generally unfavorable on the basis of lithologic characteristics, distance from a possible source of uranium, lack of apparent mineralization, and the scarcity of anomalies on gamma-ray logs or in rock, water, and stream-sediment samples. The lower Chinle from the Moss Back Member down to the base of the formation is favorable because it is a known producer. New areas for exploration are all subsurface. Both Salt Wash and Brushy Basin Members of the Morrison Formation are favorable. The Salt Wash Member is favorable because it is a known producer. The Brushy Basin Member is favorable as a low-grade resource

Integrated numerical modeling for basin-wide water management: The case of the Rattlesnake Creek basin in south-central Kansas

Science.gov (United States)

Sophocleous, M.A.; Koelliker, J.K.; Govindaraju, R.S.; Birdie, T.; Ramireddygari, S.R.; Perkins, S.P.

1999-01-01

The objective of this article is to develop and implement a comprehensive computer model that is capable of simulating the surface-water, ground-water, and stream-aquifer interactions on a continuous basis for the Rattlesnake Creek basin in south-central Kansas. The model is to be used as a tool for evaluating long-term water-management strategies. The agriculturally-based watershed model SWAT and the ground-water model MODFLOW with stream-aquifer interaction routines, suitably modified, were linked into a comprehensive basin model known as SWATMOD. The hydrologic response unit concept was implemented to overcome the quasi-lumped nature of SWAT and represent the heterogeneity within each subbasin of the basin model. A graphical user-interface and a decision support system were also developed to evaluate scenarios involving manipulation of water fights and agricultural land uses on stream-aquifer system response. An extensive sensitivity analysis on model parameters was conducted, and model limitations and parameter uncertainties were emphasized. A combination of trial-and-error and inverse modeling techniques were employed to calibrate the model against multiple calibration targets of measured ground-water levels, streamflows, and reported irrigation amounts. The split-sample technique was employed for corroborating the calibrated model. The model was run for a 40 y historical simulation period, and a 40 y prediction period. A number of hypothetical management scenarios involving reductions and variations in withdrawal rates and patterns were simulated. The SWATMOD model was developed as a hydrologically rational low-flow model for analyzing, in a user-friendly manner, the conditions in the basin when there is a shortage of water.

Schematic designs for penetration seals for a repository in the Paradox Basin

International Nuclear Information System (INIS)

Kelsall, P.C.; Meyer, D.; Case, J.B.; Coons, W.E.

1985-12-01

The isolation of radioactive wastes in geologic repositories requires that human-made penetrations such as shafts, tunnels, or boreholes are adequately sealed. This report describes schematic seal designs for a repository in bedded salt referenced to the stratigraphy of the Paradox Basin. The designs are presented for extensive peer review and will be updated as conceptual designs if the Paraodx Basin is selected as a candidate repository site. The principal components used in the shaft seal system are concrete bulkheads interspersed with highly compacted bentonite-rich earth fill. In the repository-level tunnels and rooms, the principal material used in the seal system is crushed salt obtained from excavating the repository. It is anticipated that crushed salt will consolidate in response to closure of the repository rooms, to the degree that mechanical and hydrologic properties will eventually match those of undisturbed, intact salt. For Paradox Basin Cycle 6 salt, analyses indictate that this process will require approximately 300 years for a seal located at the base of one of the repository shafts (where there is little increase in temperature due to waste emplacement) and approximately 140 years for a seal located in a main passageway within the repository. These analyses are based on uncertain laboratory data regarding intact salt creep rates and crushed salt consolidation characteristics, and must be regarded as preliminary

Mediterranean salt giants beyond the evaporite model: The Sicily perspective

Science.gov (United States)

Carmelo Manuella, Fabio; Scribano, Vittorio; Carbone, Serafina; Hovland, Martin; Johnsen, Hans-Konrad; Rueslåtten, Håkon

2017-04-01

Mediterranean salt giants, occurring both in sub-seafloor and in onshore settings (the "Gessoso Solfifera Group"), are traditionally explained by repeated cycles of desiccation and replenishment of the entire basin. However, such hypotheses are strongly biased by mass balance calculations and geodynamic considerations. In addition, any hypothesis without full desiccation, still based on the evaporite model, should consider that seawater brines start to precipitate halite when 2/3 of the seawater has evaporated, and hence the level of the basin cannot be the same as the adjacent ocean. On the other hand, hydrothermal venting of hot saline brines onto the seafloor can precipitate salt in a deep marine basin if a layer of heavy brine exists along the seafloor. This process, likely related to sub-surface boiling or supercritical out-salting (Hovland et al., 2006), is consistent with geological evidence in the Red Sea "Deeps" (Hovland et al., 2015). Although supercritical out-salting and phase separation can sufficiently explain the formation of several marine salt deposits, even in deep marine settings, the Mediterranean salt giant formations can also be explained by the serpentinization model (Scribano et al., 2016). Serpentinization of abyssal peridotites does not involve seawater salts, and large quantities of saline brines accumulate in pores and fractures of the sub-seafloor serpentinites. If these rocks undergo thermal dehydration, for example, due to igneous intrusions, brines and salt slurries can migrate upwards as hydrothermal plumes, eventually venting at the seafloor, giving rise to giant salt deposits over time. These hydrothermal processes can take place in a temporal sequence, as it occurred in the "Caltanissetta Basin" (Sicily). There, salt accumulation associated with serpentinization started during Triassic times (and even earlier), and venting of heavy brines onto the seafloor eventually occurred in the Messinian via the hydrothermal plume mechanism

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-01

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

Miocene-Recent sediment flux in the south-central Alaskan fore-arc basin governed by flat-slab subduction

Science.gov (United States)

Finzel, Emily S.; Enkelmann, Eva

2017-04-01

The Cook Inlet in south-central Alaska contains the early Oligocene to Recent stratigraphic record of a fore-arc basin adjacent to a shallowly subducting oceanic plateau. Our new measured stratigraphic sections and detrital zircon U-Pb geochronology and Hf isotopes from Neogene strata and modern rivers illustrate the effects of flat-slab subduction on the depositional environments, provenance, and subsidence in fore-arc sedimentary systems. During the middle Miocene, fluvial systems emerged from the eastern, western, and northern margins of the basin. The axis of maximum subsidence was near the center of the basin, suggesting equal contributions from subsidence drivers on both margins. By the late Miocene, the axis of maximum subsidence had shifted westward and fluvial systems originating on the eastern margin of the basin above the flat-slab traversed the entire width of the basin. These mud-dominated systems reflect increased sediment flux from recycling of accretionary prism strata. Fluvial systems with headwaters above the flat-slab region continued to cross the basin during Pliocene time, but a change to sandstone-dominated strata with abundant volcanogenic grains signals a reactivation of the volcanic arc. The axis of maximum basin subsidence during late Miocene to Pliocene time is parallel to the strike of the subducting slab. Our data suggest that the character and strike-orientation of the down-going slab may provide a fundamental control on the nature of depositional systems, location of dominant provenance regions, and areas of maximum subsidence in fore-arc basins.

Hydrogeologic reconnaissance of the San Miguel River basin, southwestern Colorado

Science.gov (United States)

Ackerman, D.J.; Rush, F.E.

1984-01-01

The San Miguel River Basin encompasses 4,130 square kilometers of which about two-thirds is in the southeastern part of the Paradox Basin. The Paradox Basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Evaporite beds of mostly salt are both overlain and underlain by confining beds. Aquifers are present above and below the confining-bed sequence. The principal element of ground-water outflow from the upper aquifer is flow to the San Miguel River and its tributaries; this averages about 90 million cubic meters per year. A water budget for the lower aquifer has only two equal, unestimated elements, subsurface outflow and recharge from precipitation. The aquifers are generally isolated from the evaporite beds by the bounding confining beds; as a result, most ground water has little if any contact with the evaporites. No brines have been sampled and no brine discharges have been identified in the basin. Salt water has been reported for petroleum-exploration wells, but no active salt solution has been identified. (USGS)

Groundwater flow and its effect on salt dissolution in Gypsum Canyon watershed, Paradox Basin, southeast Utah, USA

Science.gov (United States)

Reitman, Nadine G.; Ge, Shemin; Mueller, Karl

2014-09-01

Groundwater flow is an important control on subsurface evaporite (salt) dissolution. Salt dissolution can drive faulting and associated subsidence on the land surface and increase salinity in groundwater. This study aims to understand the groundwater flow system of Gypsum Canyon watershed in the Paradox Basin, Utah, USA, and whether or not groundwater-driven dissolution affects surface deformation. The work characterizes the groundwater flow and solute transport systems of the watershed using a three-dimensional (3D) finite element flow and transport model, SUTRA. Spring samples were analyzed for stable isotopes of water and total dissolved solids. Spring water and hydraulic conductivity data provide constraints for model parameters. Model results indicate that regional groundwater flow is to the northwest towards the Colorado River, and shallow flow systems are influenced by topography. The low permeability obtained from laboratory tests is inconsistent with field observed discharges, supporting the notion that fracture permeability plays a significant role in controlling groundwater flow. Model output implies that groundwater-driven dissolution is small on average, and cannot account for volume changes in the evaporite deposits that could cause surface deformation, but it is speculated that dissolution may be highly localized and/or weaken evaporite deposits, and could lead to surface deformation over time.

Baseload Nitrate Salt Central Receiver Power Plant Design Final Report

Energy Technology Data Exchange (ETDEWEB)

Tilley, Drake [Abengoa Solar LLC, Lakewood, CO (United States); Kelly, Bruce [Abengoa Solar LLC, Lakewood, CO (United States); Burkholder, Frank [Abengoa Solar LLC, Lakewood, CO (United States)

2014-12-12

The objectives of the work were to demonstrate that a 100 MWe central receiver plant, using nitrate salt as the receiver coolant, thermal storage medium, and heat transport fluid in the steam generator, can 1) operate, at full load, for 6,400 hours each year using only solar energy, and 2) satisfy the DOE levelized energy cost goal of $0.09/kWhe (real 2009 $). To achieve these objectives the work incorporated a large range of tasks relating to many different aspects of a molten salt tower plant. The first Phase of the project focused on developing a baseline design for a Molten Salt Tower and validating areas for improvement. Tasks included a market study, receiver design, heat exchanger design, preliminary heliostat design, solar field optimization, baseline system design including PFDs and P&IDs and detailed cost estimate. The baseline plant met the initial goal of less than $0.14/kWhe, and reinforced the need to reduce costs in several key areas to reach the overall $0.09/kWhe goal. The major improvements identified from Phase I were: 1) higher temperature salt to improve cycle efficiency and reduce storage requirements, 2) an improved receiver coating to increase the efficiency of the receiver, 3) a large receiver design to maximize storage and meet the baseload hours objective, and 4) lower cost heliostat field. The second Phase of the project looked at advancing the baseline tower with the identified improvements and included key prototypes. To validate increasing the standard solar salt temperature to 600 °C a dynamic test was conducted at Sandia. The results ultimately proved the hypothesis incorrect and showed high oxide production and corrosion rates. The results lead to further testing of systems to mitigate the oxide production to be able to increase the salt temperature for a commercial plant. Foster Wheeler worked on the receiver design in both Phase I and Phase II looking at both design and lowering costs utilizing commercial fossil boiler

Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain, Final Report and Topical Reports 5-8 on Smackover Petroleum system and Underdevelopment Reservoirs

Energy Technology Data Exchange (ETDEWEB)

Mancini, Ernest A.; Puckett, T. Markham; Parcell, William C.; Llinas, Juan Carlos; Kopaska-Merkel, David C.; Townsend, Roger N.

2002-03-05

The Smackover Formation, a major hydrocarbon-producing horizon in the Mississippi Interior Salt Basin (MISB), conformably overlies the Norphlet Formation and is conformably overlain by the Buckner Anhydrite Member of the Haynesville Formation. The Norphlet-Smackover contact can be either gradational or abrupt. The thickness and lithofacies distribution of the Smackover Formation were controlled by the configuration of incipient paleotopography. The Smackover Formation has been subdivided into three informal members, referred to as the lower, middle and upper members.

Neotectonic movement and its relation to uranium metallogenesis in central-southern Songliao basin and its adjacent areas

International Nuclear Information System (INIS)

Sang Jisheng; Zhang Yongbao; Chen Weiyi

2004-01-01

The central-southern Songliao basin and its adjacent area ar located in the south of Inner Mongolian-Northeastern China neotectonic region of the circum-pacific neotectonic domain. Since Late Tertiary the neotectonic movement in the region has been being more intense, and the most obvious feature of the neotectonic movement was characterized by large-amplitude block-faulting and strong volcanic activity. The mega-scale basin-and-range tectonics and other micro-geomorphology created favourable tectonic and geomorphologic conditions for the ore-formation of in-situ leachable sandstone-type uranium deposits. Neotectonic movement played both positive and negative roles in uranium ore-formation. Neotectonics are well developed at the eastern and the southern margins of the Songliao basin, and these areas are favourable for locating in-situ leachable sandstone-type uranium deposits

Exploratory shaft conceptual design report: Permian Basin

International Nuclear Information System (INIS)

1983-07-01

This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Permian Basin locatd in the western part of Texas. Conceptualized designs for other possible locations (Paradox Basin in Utah and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

Exploratory shaft conceptual design report: Paradox Basin

International Nuclear Information System (INIS)

1983-07-01

This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Paradox Basin located in the southeastern part of Utah. Conceptualized designs for other possible locations (Permian Basin in Texas and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

Digital model of the seabed geomorphology of southern-central Espirito Santo basin and northern Campos basin; Modelo digital da geomorfologia do fundo oceanico do centro-sul da bacia do Espirito Santo e norte da bacia de Campos

Energy Technology Data Exchange (ETDEWEB)

Schreiner, Simone; Souza, Mariana Beatriz Ferraz Mendonca de; Migliorelli, Joana Paiva Robalo [Petroleo Brasileiro S. A. (PETROBRAS), Rio de Janeiro, RJ (Brazil). Unidade de Servicos de Exploracao e Producao], Emails: schreiner@petrobras.com.br, mbfms.fototerra@petrobras.com.br, joanamigli.fototerra@petrobras.com.br

2009-05-15

That communication brings the result of a bathymetric mosaic of converted in a digital model of the ocean topography, consisting of 17 seismic projects 3D, besides 17 multibeam bathymetry surveys of South-Central Espirito Santo Basin and Northern Campos Basin.

A Darriwilian (Middle Ordovician bivalve-dominated molluscan fauna from the Stairway Sandstone, Amadeus Basin, central Australia

Directory of Open Access Journals (Sweden)

Kristian G. Jakobsen

2016-12-01

Full Text Available A bivalve-dominated molluscan fauna is described from the Darriwilian (Middle Ordovician Stairway Sandstone, Amadeus Basin, central Australia. The fauna comprises 16 species of bivalves and rostroconchs plus six gastropod species which are treated under open nomenclature. Two new bivalves, Sthenodonta paenesymmetrica sp. nov. and Modiolopsis pojetai sp. nov., are described. The relatively low-diverse molluscan fauna constitutes around 62% of the total benthic macrofauna. Approximately 75% of the molluscs comprise bivalves, especially nuculoids, which were biogeographically restricted to low latitudes during the Ordovician. The molluscan assemblage displays a very high degree of endemism at species level, though the bivalve Sthenodonta eastii also occurs in the Georgina Basin farther to the northeast. This indicates a possible marine connective seaway between the Georgina and Amadeus basins during the Darriwilian. Nuculites, Cyrtodonta, and Modiolopsis are cosmopolitan and previously reported from North China, Avalonia, and Southern Gondwana.

Reconstruction of a saline, lacustrine carbonate system (Priabonian, St-Chaptes Basin, SE France): Depositional models, paleogeographic and paleoclimatic implications

Science.gov (United States)

Lettéron, Alexandre; Hamon, Youri; Fournier, François; Séranne, Michel; Pellenard, Pierre; Joseph, Philippe

2018-05-01

A 220-m thick carbonate-dominated succession has been deposited in shallow-water, saline lake environments during the early to middle Priabonian (MP17A-MP18 mammal zones) in the Saint-Chaptes Basin (south-east France). The palaeoenvironmental, paleoclimatic and palaeogeographic significance of such saline lake carbonates has been deciphered on the basis of a multi-proxy analyses including: 1) depositional and diagenetic features; 2) biological components (molluscs, benthic foraminifera, characean gyrogonites, spores and pollens); 3) carbon and oxygen stable isotopes; 4) trace elements; and 5) clay mineralogy. Five stages of lacustrine system evolution have been identified: 1) fresh-water closed lake under dry climate (unit U1); 2) fresh to brackish water lacustrine deltaic system with a mixed carbonate-siliciclastic sedimentation under relatively wet climatic conditions (unit U2); 3) salt-water lacustrine carbonate system under humid climatic setting (unit U3); 4) evaporitic lake (unit U4); and 5) closed lake with shallow-water carbonate sedimentation under subtropical to Mediterranean climate with dry seasons (unit U5). Upper Eocene aridification is evidenced to have started as early as the earliest Priabonian (unit U1: MP17A mammal zone). A change from humid to dryer climatic conditions is recorded between units U3 and U4. The early to middle Priabonian saline lake is interpreted as an athalassic (inland) lake that have been transiently connected with neighboring salt lakes influenced by seawater and/or fed with sulfates deriving from recycling of evaporites. Maximum of connection with neighboring saline lakes (Mormoiron Basin, Camargue and Central grabens, Hérault Basin) likely occurred during unit U3 and at the base of unit U5. The most likely sources of salts of these adjacent basins are: 1) Triassic evaporites derived from salt-diapirs (Rhône valley) or from paleo-outcrops located east of the Durance fault or offshore in the Gulf of Lion; or 2) marine

Biodiversity of deep-sea demersal megafauna in western and central Mediterranean basins

Directory of Open Access Journals (Sweden)

Samuele Tecchio

2011-06-01

Full Text Available Abundance, biomass and diversity patterns of bathyal and abyssal Mediterranean megafauna (fishes and invertebrates were analyzed in the western Balearic Sea, the western Ionian Sea and the eastern Ionian Sea. Sampling was conducted with a Otter-trawl Maireta System (OTMS at depths ranging from 600 to 4000 m. A series of ecological indicators were computed: total abundance and biomass, Margalef species richness, Shannon-Wiener diversity and Pielou’s index of evenness. A multidimensional scaling was applied, indicating that the megafauna communities were grouped by depth, while geographic area had a less defined influence. Margalef richness declined with depth in all three areas, but more steeply in the western Ionian Sea. Pielou’s evenness behaved differently in the three zones, showing a V-shaped curve in the eastern Ionian while showing a decreasing pattern in the other two areas. At lower slope depths, massive presence of the fishes Alepocephalus rostratus in the western basin and Bathypterois mediterraneus in the central basin caused a sharp reduction in evenness.

Estimates of ground-water recharge rates for two small basins in central Nevada

International Nuclear Information System (INIS)

Lichty, R.W.; McKinley, P.W.

1995-01-01

Estimates of ground-water recharge rates developed from hydrologic modeling studies are presented for 3-Springs and East Stewart basins, two small basins (analog sites) located in central Nevada. The analog-site studies were conducted to aid in the estimation of recharge to the paleohydrologic regime associated with ground water in the vicinity of Yucca Mountain under wetter climatic conditions. The two analog sites are located to the north and at higher elevations than Yucca Mountain, and the prevailing (current) climatic conditions at these sites is thought to be representative of the possible range of paleoclimatic conditions in the general area of Yucca Mountain during the Quaternary. Two independent modeling approaches were conducted at each of the analog sites using observed hydrologic data on precipitation, temperature, solar radiation, stream discharge, and chloride-ion water chemistry for a 6-year study period (October 1986 through September 1992). Both models quantify the hydrologic water-balance equation and yield estimates of ground-water recharge, given appropriate input data. Results of the modeling approaches support the conclusion that reasonable estimates of average-annual recharge to ground water range from about 1 to 3 centimeters per year for 3-Springs basin (the drier site), and from about 30 to 32 centimeters per year for East Stewart basin (the wetter site). The most reliable results are those derived from a reduced form of the chloride-ion model because they reflect integrated, basinwide processes in terms of only three measured variables: precipitation amount, precipitation chemistry, and streamflow chemistry

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

NARCIS (Netherlands)

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

2016-01-01

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

Basinal seamounts and seamount chains of the Central Indian Ocean: Probable near-axis origin from a fast-spreading ridge

Digital Repository Service at National Institute of Oceanography (India)

Mukhopadhyay, R.; Batiza, R.

Hydrosweep mapping of crust in the Central Indian Ocean Basin reveals abundant volcanoes occurring both as isolated seamounts and linear seamount chains parallel to flow lines. Their shapes, sizes and overall style of occurrence...

Ground-water availability in the central part of Lake Ontario basin, New York

Science.gov (United States)

Miller, Todd S.; Krebs, Martha M.

1988-01-01

A set of three maps showing surficial geology, distribution of glacial aquifers, and potential well yield in the 708 sq mi central part of the Lake Ontario basin are presented at a scale of 1:125,000. The basin is parallel to Lake Ontario and extends from Rochester in the west to Oswego in the east. Aquifers consisting primarily of sand and gravel formed where meltwaters from glaciers deposited kame and outwash sand and gravel and where wave action along shores of glacial lakes eroded, reworked , and deposited beaches. Thick deposits of well-sorted sand and gravel yield relatively large quantities of water - typically more than 100 gal/min. Aquifers consisting of thin beds of sand and (or) gravel or thick gravel that contain a large proportion of silt and fine sand yield moderate amounts of water, 10 to 100 gal/min. Dug and driven wells that tap fine to medium sand deposits typically yield 1 to 10 gal/min. (USGS)

Liking, salt taste perception and use of table salt when consuming reduced-salt chicken stews in light of South Africa's new salt regulations.

Science.gov (United States)

De Kock, H L; Zandstra, E H; Sayed, N; Wentzel-Viljoen, E

2016-01-01

This study investigated the impact of salt reduction on liking, salt taste perception, and use of table salt when consuming chicken stew in light of South Africa's new salt recommendations. In total, 432 South-African consumers (aged 35.2 ± 12.3 years) consumed a full portion of a chicken stew meal once at a central location. Four stock cube powders varying in salt content were used to prepare chicken stews: 1) no reduction - 2013 Na level; regular salt level as currently available on the South African market (24473 mg Na/100 g), 2) salt reduction smaller than 2016 level, i.e. 10%-reduced (22025 mg Na/100 g), 3) 2016 salt level, as per regulatory prescriptions (18000 mg Na/100 g), 4) 2019 salt level, as per regulatory prescriptions (13000 mg Na/100 g). Consumers were randomly allocated to consume one of the four meals. Liking, salt taste perception, and use of table salt and pepper were measured. Chicken stews prepared with reduced-salt stock powders were equally well-liked as chicken stews with the current salt level. Moreover, a gradual reduction of the salt in the chicken stews resulted in a reduced salt intake, up to an average of 19% for the total group compared to the benchmark 2013 Na level stew. However, 19% of consumers compensated by adding salt back to full compensation in some cases. More salt was added with increased reductions of salt in the meals, even to the point of full compensation. Further investigation into the impacts of nutrition communication and education about salt reduction on salt taste perception and use is needed. This research provides new consumer insights on salt use and emphasises the need for consumer-focused behaviour change approaches, in addition to reformulation of products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequence stratigraphy, sedimentary systems and petroleum plays in a low-accommodation basin: Middle to upper members of the Lower Jurassic Sangonghe Formation, Central Junggar Basin, Northwestern China

Science.gov (United States)

Feng, Youliang; Jiang, Shu; Wang, Chunfang

2015-06-01

The Lower Jurassic Junggar Basin is a low-accommodation basin in northwestern China. Because of low subsidence rates and a warm, wet climate, deposits of the Central subbasin of the Junggar Basin formed from fluvial, deltaic, shallow lake facies. Sequence stratigraphy and sedimentary systems of the Lower Jurassic members of the Sangonghe Formation (J1s) were evaluated by observing cores, interpreting wireline logs and examining seismic profiles. Two third-order sequences were recognized in the strata. The distribution of the sedimentary systems in the systems tracts shows that tectonic movement, paleorelief, paleoclimate and changes in lake level controlled the architecture of individual sequences. During the development of the lowstand systems tract (LST), the intense structural movement of the basin resulted in a significant fall in the water level in the lake, accompanied by rapid accommodation decrease. Braided rivers and their deltaic systems were also developed in the Central Junggar Basin. Sediments carried by braided rivers were deposited on upward slopes of the paleorelief, and braid-delta fronts were deposited on downward slopes. During the transgressive systems tract (TST), the tectonic movement of the basin was quiescent and the climate was warm and humid. Lake levels rose and accommodation increased quickly, shoal lines moved landward, and shore- to shallow-lake deposits, sublacustrine fans and deep-lake facies were deposited in shallow- to deep-lake environments. During the highstand systems tract (HST), the accommodation no longer increased but sediment supply continued, far exceeding accommodation. HST deposits slowly formed in shallow-lake to meandering river delta-front environments. Relatively low rates of structural subsidence and low accommodation resulted in coarse-grained successions that were fining upward. Deposits were controlled by structural movement and paleorelief within the LST to TST deposits in the Central subbasin. Fine- to medium

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

Central Diabetes Insipidus and Cisplatin-Induced Renal Salt Wasting Syndrome: A Challenging Combination.

Science.gov (United States)

Cortina, Gerard; Hansford, Jordan R; Duke, Trevor

2016-05-01

We describe a 2-year-old female with a suprasellar primitive neuroectodermal tumor and central diabetes insipidus (DI) who developed polyuria with natriuresis and subsequent hyponatremia 36 hr after cisplatin administration. The marked urinary losses of sodium in combination with a negative sodium balance led to the diagnosis of cisplatin-induced renal salt wasting syndrome (RSWS). The subsequent clinical management is very challenging. Four weeks later she was discharged from ICU without neurological sequela. The combination of cisplatin-induced RSWS with DI can be confusing and needs careful clinical assessment as inaccurate diagnosis and management can result in increased neurological injury. © 2016 Wiley Periodicals, Inc.

Availability of ground water in the middle Merrimack River basin, central and southern New Hampshire

Science.gov (United States)

Cotton, J.E.

1976-01-01

Sufficient amounts of water to supply single family homes are available from the bedrock aquifer nearly everywhere in the middle Merrimack River basin in central and southern New Hampshire. Relatively this and narrow, unconsolidated aquifers of sand or sand and gravel commonly capable of yielding more than 200 gallons per minute to properly located and constructed wells are found only in major stream valleys. The map provides a preliminary assessment of the availability of ground water in the basin, as determined by estimating the capability of the aquifers to store and transmit water. On the map, aquifers are rated as having high, medium, or low potential to yield water. Ground water in the middle Merrimack River basin is generally of good chemical quality. Most of it is clear and colorless, contains no suspended matter and practically no bacteria, water may be affected by land-use practices. Degradation of water quality may occur in unsewered residential and village areas, near solid-waste-disposal sites, agricultural land, and major highways. (Woodard-USGS)

Climate Change Impacts on Runoff Regimes at a River Basin Scale in Central Vietnam

Directory of Open Access Journals (Sweden)

Do Hoai Nam

2012-01-01

Full Text Available Global warming has resulted in significant variability of global climate especially with regard to variation in temperature and precipitation. As a result, it is expected that river flow regimes will be accordingly varied. This study presents a preliminary projection of medium-term and long-term runoff variation caused by climate change at a river basin scale. The large scale precipitation projection at the middle and the end of the 21st century under the A1B scenario simulated by the CGCM model (MRI & JMA, 300 km resolution is statistically downscaled to a basin scale and then used as input for the super-tank model for runoff analysis at the upper Thu Bon River basin in Central Vietnam. Results show that by the middle and the end of this century annual rainfall will increase slightly; together with a rising temperature, potential evapotranspiration is also projected to increase as well. The total annual runoff, as a result, is found to be not distinctly varied relative to the baseline period 1981 - 2000; however, the runoff will decrease in the dry season and increase in the rainy season. The results also indicate the delay tendency of the high river flow period, shifting from Sep-Dec at present to Oct-Jan in the future. The present study demonstrates potential impacts of climate change on streamflow regimes in attempts to propose appropriate adaptation measures and responses at the river basin scales.

Availability of water resources in the rio Bermudez micro-basin. Central Region of Costa Rica; Disponibilidad del recurso hidrico en la microcuenca del rio Bermudez. Region Central de Costa Rica

Energy Technology Data Exchange (ETDEWEB)

Hernando Echevarria, L.; Orozco Montoya, R.

2015-07-01

The Rio Bermudez micro-basin makes up part of the principal hydrological resource area in the Central Region of Costa Rica. For this reason a study was done to determine the availability of hydrological resources in said micro-basin to identify areas with potential water availability problems. A monthly water balance was calculated using land use, geomorphology and climate parameters. From these water balance studies, the amount of available water was calculated and classified into four categories, however, in this micro-basin, only three categories were identified: high, medium and moderate water availability. No areas were identified with low water availability, indicating availability is sufficient; however, there is increasing demand on water resources because over half of the micro-basin area is classified as having moderate water availability. (Author)

Morphotectonics of the Jamini River basin, Bundelkhand Craton, Central India; using remote sensing and GIS technique

Science.gov (United States)

Prakash, K.; Mohanty, T.; Pati, J. K.; Singh, S.; Chaubey, K.

2017-11-01

Morphological and morphotectonic analyses have been used to obtain information that influence hydrographic basins, predominantly these are modifications of tectonic elements and the quantitative description of landforms. Discrimination of morphotectonic indices of active tectonics of the Jamini river basin consists the analyses of asymmetry factor, ruggedness number, basin relief, gradient, basin elongation ratio, drainage density analysis, and drainage pattern analysis, which have been completed for each drainage basin using remote sensing and GIS techniques. The Jamini river is one of the major tributaries of the Betwa river in central India. The Jamini river basin is divided into five subwatersheds viz. Jamrar, Onri, Sainam, Shahzad and Baragl subwatershed. The quantitative approach of watershed development of the Jamini river basin, and its four sixth (SW1-SW4) and one fifth (SW5) order subwatersheds, was carried out using Survey of India toposheets (parts of 54I, 54K, 54L, 54O, and 54P), Landsat 7 ETM+, ASTER (GDEM) data, and field data. The Jamini river has low bifurcation index which is a positive marker of tectonic imprint on the hydrographic network. The analyses show that the geomorphological progression of the study area was robustly influenced by tectonics. The analysis demonstrates to extensional tectonics system with the following alignments: NE-SW, NW-SE, NNE-SSW, ENE-WSW, E-W, and N-S. Three major trends are followed by lower order streams viz. NE-SW, NW-SE, and E-W directions which advocate that these tectonic trends were active at least up to the Late Pleistocene. The assessment of morphotectonic indices may be used to evaluate the control of active faults on the hydrographic system. The analysis points out westward tilting of the drainage basins with strong asymmetry in some reaches, marked elongation ratio of subwatersheds, and lower order streams having close alignment with lineaments (active faults). The study facilitated to considerate the

Origins of the Salado, Seven Rivers, and San Andres salt margins in Texas and New Mexico: Revision 1: Topical report

International Nuclear Information System (INIS)

Boyd, S.D.; Murphy, P.J.

1987-02-01

The present boundaries of the San Andres, Seven Rivers, and Salado salts generally lie along the periphery of the Palo Duro and Tucumcari Basins. Various geologic mechanisms occurring singularly or in combination determined the positions of the salt margins. These mechanisms include nondeposition of salt and syndepositional and postdepositional dissolution. In New Mexico, San Andres units pinch out against the Pedernal and Sierra Grande Uplifts, indicating that nondeposition established the original salt margins there. Syndepositional dissolution of exposed Upper San Andres salts occurred in response to Guadalupian upwarp of the basin margins. Triassic erosion differentially removed Permian salt-bearing formations along the uplifts. Late Tertiary dissolution is indicated by fill of north-south trending collapse valleys. In Texas, Guadalupian upwarp along the Amarillo Uplift caused pinchout of Units 2 and 3 in the Lower San Andres and influenced the deposition of subsequent salt-bearing strata. The discontinuity of Upper San Andres evaporites across the Amarillo Uplift suggests syndepositional dissolution. Along the eastern and northeastern basin margin, dissolution may have accompanied Triassic erosion of locally uplifted Upper Permian strata. Tertiary dissolution is recognized beneath anomalously thick Ogallala Formation sections that overlie collasped Permian strata. 49 refs., 31 figs., 2 tabs

Submarine Salt Karst Terrains

Directory of Open Access Journals (Sweden)

Nico Augustin

2016-06-01

Full Text Available Karst terrains that develop in bodies of rock salt (taken as mainly of halite, NaCl are special not only for developing in one of the most soluble of all rocks, but also for developing in one of the weakest rocks. Salt is so weak that many surface-piercing salt diapirs extrude slow fountains of salt that that gravity spread downslope over deserts on land and over sea floors. Salt fountains in the deserts of Iran are usually so dry that they flow at only a few cm/yr but the few rain storms a decade so soak and weaken them that they surge at dm/day for a few days. We illustrate the only case where the rates at which different parts of one of the many tens of subaerial salt karst terrains in Iran flows downslope constrains the rates at which its subaerial salt karst terrains form. Normal seawater is only 10% saturated in NaCl. It should therefore be sufficiently aggressive to erode karst terrains into exposures of salt on the thousands of known submarine salt extrusions that have flowed or are still flowing over the floors of hundreds of submarine basins worldwide. However, we know of no attempt to constrain the processes that form submarine salt karst terrains on any of these of submarine salt extrusions. As on land, many potential submarine karst terrains are cloaked by clastic and pelagic sediments that are often hundreds of m thick. Nevertheless, detailed geophysical and bathymetric surveys have already mapped likely submarine salt karst terrains in at least the Gulf of Mexico, and the Red Sea. New images of these two areas are offered as clear evidence of submarine salt dissolution due to sinking or rising aggressive fluids. We suggest that repeated 3D surveys of distinctive features (± fixed seismic reflectors of such terrains could measure any downslope salt flow and thus offer an exceptional opportunity to constrain the rates at which submarine salt karst terrains develop. Such rates are of interest to all salt tectonicians and the many

Radiolarian abundance and geochemistry of the surface-sediments from the Central Indian Basin: Inferences to Antarctic bottom water current

Digital Repository Service at National Institute of Oceanography (India)

Gupta, S.M.; Jauhari, P.

The distribution trend of numbers of radiolarian shells/gram dry sediment, biogenic silica, organic carbon, and the carbon/nitrogen ratios in the surface sediments of the Central Indian Basin is similar. Ratios of two suborders of radiolaria, i...

Groundwater sustainability in Central Australia studied using chlorine-36

International Nuclear Information System (INIS)

Cresswell, R.G.; Fifield, L.K.; Jacobson, G.

1998-01-01

The sustainability of Aboriginal community water supplies in arid Central Australia has been evaluated using the radioisotope chlorine-36 as a tracer within groundwaters to indicate the age of waters being tapped by local bores. Shallow regional groundwaters from fractured sandstones of the Ngalia Basin, fractured metamorphic rocks and Cainozoic sands and gravels show a bimodal distribution of 36 Cl ratios. The higher ratio probably represents modern (Holocene) recharge diluted with windblown salts from local playa lakes and is seen in bores around the margin. The lower ratio corresponds to a 36 Cl age of 80-100ka, implying that the last major recharge occurred during the last interglacial. These values are mainly observed in the interior of the basin, and are believed to be minimum ages for most of the shallow groundwaters in this region. Substantial recharge only appears to occur during favourable interglacial climatic regimes. Most community water supplies depend on these waters. (authors)

Chronology of fluvial terrace sequences for large Atlantic rivers in the Iberian Peninsula (Upper Tagus and Duero drainage basins, Central Spain)

Science.gov (United States)

Silva, Pablo G.; Roquero, Elvira; López-Recio, Mario; Huerta, Pedro; Martínez-Graña, Antonio M.

2017-06-01

This work analyses the chronology of fluvial terrace sequences of the two most important fluvial basins from central Spain draining to the Atlantic Ocean (Upper Tagus and Duero drainage basins). Both basins evolved under similar Mediterranean climatic conditions throughout the Pleistocene and present comparable number of fluvial terraces (16-17) after excluding the higher terrace levels of the Tagus (T1-T5) entrenched in the Raña surface. These higher ;rañizo terraces; was formed in response to fan-head trenching in this high alluvial piedmont (+220 m) and therefore not properly controlled by Quaternary fluvial downcutting. The study accomplishes the implementation of multiple regression analyses for terrace height-age relationships. To transform relative terrace heights above the present river thalwegs (i.e. +100 m) in numerical ages a ;height-age transference function; has been developed on the basis of preliminary statistical geochronological approaches proposed for Central Spain. The resultant height-age transference function gather 73 published geochronological data for terrace sequences, featuring a 3rd Order Polynomial Function (R2 0.90). This function describes the overall trend of valley downcutting for the last c. 2.3 Ma in Central Spain and is used to assign numerical ages to terrace levels at different relative elevation.

Regional Hydrology of the Green River-Moab Area, Northwestern Paradox Basin, Utah

OpenAIRE

United States Geological Survey

1982-01-01

The Green River-Moab area encompasses about 7,800 square kilometers or about 25 percent of the Paradox basin. The entire Paradox basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite (salt) beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Confining beds consist of evaporite beds of mostly salt, and overlying and underlying thick sequences of rocks with...

Exploratory shaft conceptual design report: Gulf Interior Region salt domes

International Nuclear Information System (INIS)

1983-07-01

This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Gulf Interior Region of the United States (Louisiana and Mississippi). Conceptualized designs for other possible locations (Paradox Basin in Utah and Permian Basin in Texas) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in-situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homoqeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptural design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

Hydrocarbons in the Bay of Bengal and Central Indian Basin bottom sediments: Indicators of geochemical processes in the lithosphere

Digital Repository Service at National Institute of Oceanography (India)

Chernova, T.G.; Paropkari, A.L.; Pikovskii, Yu.I.; Alekseeva, T.A.

A study on the bulk distributions and molecular structures of n-alkanes and polycyclic aromatic hydrocarbons (PAH) in organic matter of the sediments from the Bay of Bengal and the Eastern and Central Indian Basins was underdaken. The former two...

Introduction to selected references on fossil fuels of the central and southern Appalachian basin: Chapter H.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

Science.gov (United States)

Ruppert, Leslie F.; Lentz, Erika E.; Tewalt, Susan J.; Román Colón, Yomayra A.; Ruppert, Leslie F.; Ryder, Robert T.

2014-01-01

The Appalachian basin contains abundant coal and petroleum resources that have been studied and extracted for at least 150 years. In this volume, U.S. Geological Survey (USGS) scientists describe the geologic framework and geochemical character of the fossil-fuel resources of the central and southern Appalachian basin. Separate subchapters (some previously published) contain geologic cross sections; seismic profiles; burial history models; assessments of Carboniferous coalbed methane and Devonian shale gas; distribution information for oil, gas, and coal fields; data on the geochemistry of natural gas and oil; and the fossil-fuel production history of the basin. Although each chapter and subchapter includes references cited, many historical or other important references on Appalachian basin and global fossil-fuel science were omitted because they were not directly applicable to the chapters.

Borehole locations on seven interior salt domes

International Nuclear Information System (INIS)

Simcox, A.C.; Wampler, S.L.

1982-08-01

This report is designed as an inventory of all wells known to have been drilled within a five-mile radius of each of seven salt domes within the Interior Salt Basin in east Texas, northern Louisiana and Mississippi. There are 72 boreholes that entered salt above an elevation of -3000 feet mean sea level. For these, details of location, drilling dates, depth of casing and cement, elevation of top of caprock and salt, etc., are given on tables in the appendix. Of the seven domes, Oakwood has the largest number of boreholes, thirty-eight (including two sidetracked wells) that enter the salt stock above -3000 feet mean sea level; another dome in northeast Texas, Keechi, has eight; in northern Louisiana, Rayburn's has four and Vacherie has five; in southern Mississippi, Cypress Creek has seven, Lampton has one, and Richton has nine. In addition, all wells known outside the supra-domal area, but within a five-mile radius of the center of the 7 domes are separately catalogued

Environmental assessment of water-salt regime of irrigated soils in the Central-Chernozem Region of Russia

Science.gov (United States)

Alaeva, Liliia; Negrobova, Elena; Jablonskikh, Lidiia; Rumyantseva, Irina

2016-04-01

A large part of Central Chernozem Region is located in the zone of risky agriculture. This led to intensive use of soil in the irrigation system. Therefore, a detailed analysis of water-salt regime of irrigated soils required for ecological state assessment of soils for irrigation. In the investigated area the fone component of the soil cover on the levelled plateau are chernozems. On the slopes formed a meadow-chernozem soils. Parent material is a cover loess-like calcareous non-saline clay. In these soils, our studies found component-quantitative composition of the aqueous extract, the chemism of salinity, which allowed us to make conclusions about the direction of the salinisation process in soils when used in the system of irrigated agriculture. By quantity water extract chernozems are non-saline, the ratio of anions and cations are chloride-sulphate magnesium-calcium salinization. In the composition of easily soluble salts dominated by Ca(HCO3)2. On sum of toxic salts in the soils are non-saline. This type and chemism of salinity deep brackish groundwater (more than 5 m) can be actively used in the system of rational irrigation. The meadow-chernozem soils formed under conditions of increased surface and soil moisture in the shallow brackish water at a depth of 3-5 m. These soils by quantity water extract are non-saline, anionic-cationic ratio - chloride-sulphate magnesium-calcium salinization. Permanent components of salt associations are Ca(HCO3)2, MgCl2, Na2SO4. On sum of toxic salts in the soil is not saline throughout the profile. The chemism of salinity and the proximity of groundwater at irregular watering can lead to the rise of groundwater level, the development of gleyed and sodium alkalinization. Thus, the introduction of intensive irrigated agriculture on chernozems and hydromorphic analogues may lead to the development in them of negative consequences. The most dynamic indicator is the water-salt regime, the systematic monitoring and control which

A giant oil seep at a salt-induced escarpment of the São Paulo Plateau, Espírito Santo Basin, off Brazil: Host rock characteristics and geochemistry

Science.gov (United States)

Freire, Antonio Fernando Menezes; Iemini, Juliana Andrade; Viana, Adriano Roessler; Magnavita, Luciano Portugal; Dehler, Nolan Maia; Kowsmann, Renato Oscar; Miller, Dennis James; Bezerra, Sabrina Helena Diniz Gilaberte; Zerfass, Geise de Santana dos Anjos; Shimabukuro, Seirin; Nóbrega, Marcos, II

2017-12-01

An international research cruise named Iatá-Piuna took place on the São Paulo Plateau on May 2013 in the Campos and Espírito Santo basins, off Brazil. The cruise was carried ou on board the research vessel (R/V) Yokosuka that hosts the human operated vehicle (HOV) SHINKAI 6500. It aimed at finding chemosynthetic communities, composed of organisms capable of generating their own vital energy by metabolizing organic and inorganic compounds related to seeps. Identification of these organisms could provide information for understanding the origin of life, since they may resemble primitive organisms that existed in the initial stages of life on Earth. During Leg 2 (May 10-24, 2013), however, dives on the northern part of the São Paulo Plateau at the Espírito Santo Basin led to the discovery of a giant oil seep. The seep, ca. 3 nautical miles (ca. 5.6 km) in length is located along an outcrop of Eocene rocks on a salt-induced escarpment of the plateau and at a water depth of ca. 2700 m. The 200 m relief of the seafloor suggests that the seep takes place along an active fault system driven by salt diapirism. The oil was analyzed and identified as a severely biodegraded marine oil, generated by carbonate rocks within a minibasin located to the east of the escarpment. This represents valuable exploratory information because it proves that an active petroleum system is present in the context of minibasins associated with salt diapirism in the area.

Pollen record of the penultimate glacial period in Yuchi Basin, Central Taiwan

Science.gov (United States)

Lai, Hsiao-Yin; Liew, Ping-Mei

2010-05-01

Pollen records of the penultimate glacial period are scare not only in Taiwan, but also in East Asia area. Hence, this study intends to provide a new pollen record from a site, Yuchi Basin, in central Taiwan, which may improve our knowledge of the penultimate glacial period. The sediment core, CTN6, was drilled in the northern part of Yuchi Basin. The core is 29.4 m in length and the sampling interval is 10 cm. In total, 86 samples are processed for pollen analysis. Three pollen zones (I,II and III) are determined according to the ratio of arboreal pollens (AP) and non-arboreal pollens (NAP). Because of the scarcity of dating data, pollen assemblages compared with previous pollen records at peripheral areas is utilized to estimate the ages of each pollen zone. AP dominate (60%) Zone I and III, which consist mainly of Cyclobalanopsis-Castanopsis. Thus, Zone I may mark the MIS 5 because of a Cyclobalanopsis-Castanopsis dominant condition. In Zone II, the increase in NAP and pollen of Taxodiaceae and decrease in pollens of Cyclobalanopsis-Castanopsis indicates the penultimate glacial period, i.e. MIS 6. In contrast to the evergreen broadleaved forest found there today, the herbs occupied the basin in Zone II, indicating a relatively dry climate condition than present. Furthermore, during the penultimate glacial period, the climate condition of early part is wetter, evidenced by a higher AP/NAP in Zone IIb. Finally, comparing with the last glacial period in Toushe, we suggest that the penultimate glacial period is drier due to the lower AP/NAP.

Value of the principles of ''isolation of basins and their boundaries'' and ''isolation of basins and elevations'' in prospecting for oil and gas in the oil and gas basin of China

Energy Technology Data Exchange (ETDEWEB)

Chzhan, V.; Li, Yu.; Se, M.

1982-01-01

A feature of the Chinese oil and gas basins is their fracturing into a large number (to several dozen in one oil and gas basin) isolated basins which are controlled by fault disorders. In these basins in which thick masses of Mesozoic and mainly Cenozoic sedimentary rocks are developed, the main volumes of source rocks are concentrated. Migration of hydrocarbons usually occurs to short distances not exceeding tens of kilometers. From the experience of prospecting and exploration back in the 1950's it was established that thick masses in the central zones of the basins are favorable for processes of hydrocarbon generation, while accumulation occurs in the elevated peripheral parts of the basins and in the regions of the central elevations. The zones of articulation of the central elevations and the edges of the basins are very promising for prospecting for local structures. Examples of large fields which are subordinate to these laws are the largest oil fields in China, Lyakhoe, Dagan and Shenli which are located along the edges of the Bokhayvan basin in the North Chinese oil and gas basin and the Datsin field which is confined to the central elevation of the Sunlyao basin.

Quantifying present and future glacier melt-water contribution to runoff in a central Himalayan river basin

Directory of Open Access Journals (Sweden)

M. Prasch

2013-05-01

Full Text Available Water supply of most lowland cultures heavily depends on rain and melt water from the upstream mountains. Especially melt-water release of alpine mountain ranges is usually attributed a pivotal role for the water supply of large downstream regions. Water scarcity is assumed as consequence of glacier shrinkage and possible disappearance due to global climate change (GCC, in particular for large parts of Central and Southeast Asia. In this paper, the application and validation of a coupled modeling approach with regional climate model (RCM outputs and a process-oriented glacier and hydrological model is presented for the central Himalayan Lhasa River basin despite scarce data availability. Current and possible future contributions of ice melt to runoff along the river network are spatially explicitly shown. Its role among the other water balance components is presented. Although glaciers have retreated and will continue to retreat according to the chosen climate scenarios, water availability is and will be primarily determined by monsoon precipitation and snowmelt. Ice melt from glaciers is and will be a minor runoff component in summer monsoon-dominated Himalayan river basins.

Petroleum systems and hydrocarbon accumulation models in the Santos Basin, SP, Brazil; Sistemas petroliferos e modelos de acumulacao de hidrocarbonetos na Bacia de Santos

Energy Technology Data Exchange (ETDEWEB)

Chang, Hung Kiang; Assine, Mario Luis; Correa, Fernando Santos; Tinen, Julio Setsuo [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Lab. de Estudos de Bacias]. E-mails: chang@rc.unesp.br; assine@rc.unesp.br; fscorrea@rc.unesp.br; jstinen@rc.unesp.br; Vidal, Alexandre Campane; Koike, Luzia [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro de Estudos de Petroleo]. E-mails: vidal@ige.unicamp.br; luzia@iqm.unicamp.br

2008-07-01

The Santos Basin was formed by rifting process during Mesozoic Afro-American separation. Sediment accumulation initiated with fluvial-lacustrine deposits, passing to evaporitic stage until reaching marginal basin stages. The analysis of hydrocarbon potential of Santos Basin identified two petroleum systems: Guaratiba-Guaruja and Itajai-Acu-Ilhabela. The Guaratiba Formation is less known in the Santos Basin because of small number of wells that have penetrated the rift section. By comparison with Campos Basin, hydrocarbons are of saline lacustrine origin deposited in Aptian age. Analogous to Campos Basin the major source rock is of saline-lacustrine origin, which has been confirmed from geochemical analyses of oil samples recovered from the various fields. These analyses also identified marine source rock contribution, indicating the Itajai-Acu source rock went through oil-window, particularly in structural lows generated by halokynesis. Models of hydrocarbon accumulation consider Guaratiba Formacao as the major source rock for shallow carbonate reservoirs of Guaruja Formacao and for late Albian to Miocene turbidites, as well as siliciclastic and carbonate reservoirs of the rift phase. Migration occurs along salt window and through carrier-beds. The seal rock is composed of shales and limestones intercalated with reservoir facies of the post-rift section and by thick evaporites overlying rift section, especially in the deeper water. In the shallow portion, shale inter-tongued with reservoir rocks is the main seal rock. The hydrocarbon generation and expulsion in the central-north portion of the basin is caused by overburden of a thick Senonian section. Traps can be structural (rollovers and turtle), stratigraphic (pinch-outs) and mixed origins (pinch-outs of turbidites against salt domes). (author)

Forming mechanism of the Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin

Directory of Open Access Journals (Sweden)

Heng Fu

2017-07-01

Full Text Available The Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin are important oil and gas exploration targets in the basin, but their dissolution mechanisms are in controversy. In this paper, based on the integrated study of sedimentation, sequence and reservoir, together with microscopic analysis and macroscopic seismic data analysis, the carbonate karst reservoirs in the study area were divided into three types: dissolved pore-cavity limestone reservoir, pore-cavity dolomite reservoir and fracture-cavity siliceous reservoir, and their forming mechanisms were discussed respectively. Some findings were obtained. First, dissolved pore-cavity limestone reservoirs are distributed in the upper Yingshan Fm and Yijianfang Fm of the Ordovician vertically, while pore-cavity dolomite reservoirs are mainly developed in the Penglai Fm and lower Yingshan Fm of the Ordovician with great thickness. Second, dissolved pore-cavity limestone reservoirs were formed by karstification on the third-order sequence boundary (lowstand tract, while pore-cavity dolomite reservoirs were formed by deep burial dolomitization controlled by karstification on the third-order sequence boundary, both of which are distributed in the highstand tract below the third-order sequence boundary. Third, siliceous reservoirs are developed under the control of faulting, as a result of reworking of deep hydrothermal fluids along faults to the limestone, and the siliceous reservoirs and their hydrothermal solution fracture-cavity systems are distributed near faults. It is further predicted that, in addition to the three types of reservoir above, platform-margin reef-flat reservoirs are developed in the Ordovician on the northern slope of central Tarim Basin.

Evaluation Of Hydraulic Potentiality For The Generation Of Hydroelectric To Small Scale In The Basin Of The CHICAMOCHA River - Small Hydroelectric Centrals

International Nuclear Information System (INIS)

Pacheco P, Claudia M.; Parga C, Gloria M.

1995-01-01

In development of the agreement of technical and scientific cooperation established between the INEA and the Catholic University of Colombia, the program of Evaluation of Hydraulic Potentiality for Small Central was developed, whose purpose is to take the service to smaller population and villages of all the towns of the country. To begin the program the area corresponding to the basin of Chicamocha river was selected, since this region that corresponds to 72 towns of Boyaca and Santander, has good information, thanks to the diagnosis carried out by the Inderena with the purpose of formulating a Plan of Classification and Handling of the Basin. The work consisted on the identification of all the micro basins, the analysis of the demand of energy of the settled population, to evaluate the generating capacity of the flows of water and, according to the results, to propose alternatives for the design of small hydroelectric centrals (PCH) in accordance with the needs

Thin- and thick-skinned salt tectonics in the Netherlands: a quantitative approach

NARCIS (Netherlands)

Veen, J.H. ten; Gessel, S.F. van; Dulk, M. den

2012-01-01

The Zechstein salt in the Dutch part of the North Sea Basin played a key role in the generation of successful petroleum plays. This is not only because of its sealing capacity, but also because the salt occurs in structures that provide lateral and vertical traps. The structural styles of areas with

Basement inheritance and salt tectonics in the SE Barents Sea: Insights from new potential field data

Science.gov (United States)

Gernigon, L.; Broenner, M.; Dumais, M. A.; Gradmann, S.; Grønlie, A.; Nasuti, A.; Roberts, D.

2017-12-01

The tectonic evolution of the former `grey zone' between Russia and Norway has so far remained poorly constrained due to a lack of geophysical data. In 2014, we carried out a new aeromagnetic survey (BASAR-14) in the southern part of the new Norwegian offshore territory. Caledonian and Timanian structures, highlighted by the new potential field data, dominate the basement patterns and have exerted a strong influence on the structure and development of the overlying basins and basement highs. Clearly associated with NW-SE-oriented Timanian trends, the Tiddlybanken Basin represents an atypical sag basin that developed at the southern edge of the Fedynsky High. Regional extension and rapid sedimentation initiated the salt tectonics in the Barents Sea in the Early Triassic. Some of the pillows became diapiric during the Early Triassic and rejuvenated during subsequent Jurassic-Tertiary episodes of regional extension and/or compression. At present, quite a few large diapiric salt domes along the Nordkapp and Tiddlybanken basins are relatively shallow, locally reaching the seabed and thus show a clear bathymetric and magnetic signature. Quantitative modelling along 2D seismic transects was also carried out to constrain the structural and basement composition of the study area. The predominant NE-SW Mesozoic trend of the Nordkapp Basin represents a major crustal hinge zone between the Finnmark Platform, poorly affected by major crustal deformation, and the Bjarmeland Platform where Late Palaeozoic rifting controlled the widespread accumulation of salt deposits in Late Carboniferous-Early Permian time. The entire structure and segmentation of the Nordkapp Basin have been influenced by the inherited basement configuration highlighted by the new aeromagnetic data. Both the Nordkapp and the Tiddlybanken basins appear to lie at the edge of a peculiar thick and rigid crustal feature that coincides with a highly magnetic region. The abrupt termination of the eastern Nordkapp

Projected Salt Waste Production from a Commercial Pyroprocessing Facility

Directory of Open Access Journals (Sweden)

Michael F. Simpson

2013-01-01

Full Text Available Pyroprocessing of used nuclear fuel inevitably produces salt waste from electrorefining and/or oxide reduction unit operations. Various process design characteristics can affect the actual mass of such waste produced. This paper examines both oxide and metal fuel treatment, estimates the amount of salt waste generated, and assesses potential benefit of process options to mitigate the generation of salt waste. For reference purposes, a facility is considered in which 100 MT/year of fuel is processed. Salt waste estimates range from 8 to 20 MT/year from considering numerous scenarios. It appears that some benefit may be derived from advanced processes for separating fission products from molten salt waste, but the degree of improvement is limited. Waste form production is also considered but appears to be economically unfavorable. Direct disposal of salt into a salt basin type repository is found to be the most promising with respect to minimizing the impact of waste generation on the economic feasibility and sustainability of pyroprocessing.

Morphotectonic control of the Białka drainage basin (Central Carpathians: Insights from DEM and morphometric analysis.

Directory of Open Access Journals (Sweden)

Wołosiewicz Bartosz

2016-06-01

Full Text Available The Białka river valley is directly related to a deep NNW-SSE oriented fault zone. According to the results of previous morphometric analyses, the Białka drainage basin is one of the most tectonically active zones in the Central Carpathians. It is also located within an area of high seismic activity.

A systematic technique for the sequential restoration of salt structures

Science.gov (United States)

Rowan, Mark G.

1993-12-01

area of offshore Louisiana. The section is characterized by a variety of salt structures, including salt rollers, a diapiric massif, a remnant salt sheet, and a salt weld, which are shown to have derived from an originally continuous salt sheet which has been modified by sedimentary loading. Early loading created vertical basin growth that was accommodated primarily by salt withdrawal and associated diapiric rise through the process of downbuilding. Once the salt weld formed, continued sedimentation was accommodated by a lateral increase in basin size caused by down-dip extension on listric growth faults.

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)

A study on the evolution of Indian Ocean triple junction and the process of deformation in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Murthy, K.S.R.; Rao, T.C.S.

It is generally presumed that the intraplate deformation in the Central Indian Basin (CIB) is a direct consequence of spreading across the South East Indian Ridge and the resistance to shortening at the continental collision between India...

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

Spatial distribution level of land erosion disposition based on the analysis of slope on Central Lematang sub basin

Science.gov (United States)

Putranto, Dinar Dwi Anugerah; Sarino, Yuono, Agus Lestari

2017-11-01

Soil erosion is a natural process that is influenced by the magnitude of rainfall intensity, land cover, slope, soil type and soil processing system. However, it is often accelerated by human activities, such as improper cultivation of agricultural land, clearing of forest land for mining activities, and changes in topographic area due to use for other purposes such as pile materials, mined pits and so on. The Central Lematang sub-basin is part of the Lematang sub basin, at the Musi River Region Unit, South Sumatra Province, in Indonesia, which has a topographic shape with varying types of slope and altitude. The critical condition of Central Lematang sub basin has been at an alarming rate, as more than 47.5% of topographic and land use changes are dominated by coal mining activities and forest encroachment by communities. The method used in predicting erosion is by USPED (Unit Stream Power Erosion and Disposition). This is because the USPED [1] method can predict not only sediment transport but also the value of peeling (detachment) and sediment deposition. From slope analysis result, it is found that the highest erosion potential value is found on slope (8-15%) and the sediment is carried on a steep slope (15-25%). Meanwhile, the high sediment deposition area is found in the waters of 5.226 tons / ha / year, the steeper area of 2.12 tons / ha / year.

Origin of ash in the Central Indian Ocean Basin and its implication for the volume estimate of the 74,000 year BP Youngest Toba eruption

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Pearce, N.J.G.; Banakar, V.K.; Parthiban, G.

.86) 4.22 (0 .33) ? 4.94 N 91 274 72 53 16 1, Central Indian Ocean Basin 7 (present study); 2, YTT from Sum a tra, Malaysia, Bay of Bengal and India 10 ; 3, YTT from the Indian subcont i- nent 15 ; 4, YTT from....4 7.5 6.6 5.9 6.9 6.9 5.1 5.8 6.5 1, Central Indian Ocean Basin (pr esent study, n = 8); 2, YTT from Sumatra, Malaysia, ODP site 758, Bay of Bengal and India 10 ( n...

Origin and evolution of Sariñena Lake (central Ebro Basin): A piping-based model

Science.gov (United States)

Castañeda, Carmen; Javier Gracia, F.; Rodríguez-Ochoa, Rafael; Zarroca, Mario; Roqué, Carles; Linares, Rogelio; Desir, Gloria

2017-08-01

The origin and nature of the numerous lakes in the central Ebro Basin have been interpreted according to the prevailing arid or semiarid conditions, the easily-eroded materials and the solubility of the gypsum- and/or carbonate-rich Tertiary/Cenozoic substratum, involving important dissolution (karstic) and/or aeolian deflation. However, the origin of Sariñena Lake, the largest in the central Ebro Basin, remains unknown since the typical lake-generating processes in the region are not applicable. This work provides significant clues to the genesis and evolution of Sariñena Lake in a regional context. The combination of geomorphological mapping and high resolution LiDAR data together with sedimentological observations, the characterisation of soils and sediments around the lake, and the application of high-resolution geophysical techniques suggest that piping is the major genetic process driving the evolution of the Sariñena depression and lake. Field evidence demonstrates that piping is, at present, the most important erosive process in the region, generating significant collapse and surface lowering. Sariñena Lake is located within a deep endorheic depression excavated from Na-rich Tertiary materials. This work hypothesises that once an early, fluvially-originated palustrine area had developed, the progressive lowering of the regional water table linked to regional fluvial incision favoured the establishment of a hydrological gradient high enough to trigger piping processes within the claystones and siltstones underlying the original palustrine area. The Quaternary evolution of the Sariñena lacustrine basin was then controlled by successive water table fluctuations, linked to different phases of incision and alluvial deposition in the surrounding fluvial systems. All the evidence supporting a piping-related origin for this lake, together with examples of lakes generated by similar processes in different contexts, is used to propose a new genetic type of

Assessment of tectonic hazards to waste storage in interior-basin salt domes

International Nuclear Information System (INIS)

Kehle, R.

1979-01-01

Salt domes in the northern Gulf of Mexico may make ideal sites for storage of radioactive waste because the area is tectonically quiet. The stability of such salt domes and the tectonic activity are discussed

Rodents from the Upper Miocene Tuğlu Formation (Çankırı Basin, Central Anatolia, Turkey)

NARCIS (Netherlands)

Joniak, Peter; de Bruijn, Hans

2015-01-01

The upper Miocene assemblages of rodents collected from two layers of the type section of the Tuğlu Formation (Çankırı Basin, Central Anatolia, Turkey) are described. The assemblage from the lower level is considerably less diverse than that from the upper level. It contains Progonomys together with

Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin

OpenAIRE

Sobrinho, R. L.; Bernardes, M. C.; Abril, G.; Kim, J. H.; Zell, C. I.; Mortillaro, J. M.; Meziane, T.; Moreira Turcq, Patricia; Damste, J. S. S.

2016-01-01

In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Miratuba, and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochem...

Along strike behavior of the Tizi n' Firest fault during the Lower Jurassic rifting (Central High Atlas Carbonate basin, Morocco)

Science.gov (United States)

Sarih, S.; Quiquerez, A.; Allemand, P.; Garcia, J. P.; El Hariri, K.

2018-03-01

The purpose of this study is to document the along-strike early syn-rift history of the Lower Jurassic Carbonate basin of the Central High Atlas (Morocco) by combining sedimentological observations and high-resolution biostratigraphy. Six sections, each from the Sinemurian to the Upper Pliensbachian, were investigated along a 75 km-long transect at the hanging wall of a major fault of the Lower Jurassic Basin (i.e. the Tizi n' Firest fault). Depositional geometries of the early syn-rift deposits were reconstructed from the correlation between eight main timelines dated by biochronological markers for a time span covering about 6 Ma. Depocentre migration was examined and accommodation rates were calculated at the sub-zone timescale to discuss the along-strike-fault behavior of the Lower Jurassic basin formation. The early stages of extension are marked by contrasted along-strike variations in depositional geometry thickness, depocentre migration and accommodation rates, leading to the growth of three independent sub-basins (i.e. western, central, and eastern), ranging in size from 30 to 50 km, and displaying three contrasted tectono-sedimentary histories. Our results suggest that, during the early rifting phase, tectonic activity was not a continuous and progressive process evolving towards a rift climax stage, but rather a series of acceleration periods that alternated with periods of much reduced activity. The length of active fault segments is estimated at about 15-20 km, with a lifespan of a few ammonite sub-zones (> 2-3 Ma).

Evolution of the east-central San Jose del Cabo basin, Baja California Sur, Mexico

Science.gov (United States)

McTeague, M. S.; Umhoefer, P. J.; Schwennicke, T.; Ingle, J. C.; Cortes Martinez, M.

2006-12-01

The San Jose del Cabo basin at the southern tip of the Baja California peninsula records the early tectonic evolution of the west side of the Gulf of California. This study focused on the east central margin of the basin. The basal La Calera Formation unconformably overlies Cretaceous granite and consists of conglomerate, pebbly sandstone and conglomerate, and sandstone deposited in alluvial fans and fan-deltas. Deposition of the La Calera Formation was from ca. 9-14 Ma. The lower member of the Trinidad Formation was deposited beginning ca. 9-13 Ma and consists of sandstone, mudstone, and shelly mudstone deposited in nearshore and estuarine environments. These age estimates are based on sedimentation rates and foraminifera and coccoliths from the NN 11A nannozone (7.4 8.6 Ma, GTS 2004). The middle member of the Trinidad Formation consists of deeper water mudstones deposited by turbidity currents and suspension settling in a shelf to slope and conglomerates deposited by submarine debris flows on the shelf. The basin began earlier than previously thought. The oldest marine rocks are ca.9-13 Ma, while sedimentation on the east side began at ca. 9-14 Ma, synchronous with estimates of initiation of offset on the San Jose del Cabo fault. The Zapote fault is a down-to-the-east normal and sinistral-oblique fault that exposes a wedge of granite and older strata in the footwall to the west. The fault was active during sedimentation in the late Miocene and possibly later. The fault divides the study area into an eastern hanging wall subbasin and western footwall subbasin. The eastern subbasin formed an embayment in the eastern margin of the Cabo basin. A regional flooding surface (ca. 8 Ma) can be correlated across the fault that marks a major marine incursion. Depositional systems evolved rapidly from coarse-grained terrestrial systems to fine-grained marine and estuarine systems. The Cabo basin provides an excellent analogue for comparison with offshore basins, which are

HYDROGEOMORPHIC SETTING, CHARACTERISTICS, AND RESPONSE TO STREAM INCISION OF MONTANA RIPARIAN MEADOWS IN THE CENTRAL GREAT BASIN--IMPLICATIONS FOR RESTORATION

Science.gov (United States)

Riparian wet meadow complexes in the mountains of the central Great Basin are scarce, ecologically important systems that are threatened by stream incision. An interdisciplinary group has investigated 1) the origin, characteristics, and controls on the evolution of these riparian...

Geohydrolic studies of Gulf Coast interior salt domes

International Nuclear Information System (INIS)

Smith, C.G. Jr.

1977-01-01

Disposal of high-level radioactive wastes in Gulf Coast salt domes requires that the cavities be free from groundwater dissolution for 250,000 years. Salinity variations of groundwater near selected domes were investigated. Saline groundwater anomalies (saline plumes) in aquifers pierced or uplifted by the dome may be the result of salt solution by groundwater. In the Northeast Texas salt dome basin electric logs of oil and gas wells have been used to estimate groundwater salinities in aquifers near selected domes. Thus far, the analyses have revealed saline groundwater anomalies around 4 of the 9 domes studied. Estimates of the rate of salt dissolution from domes associated with saline groundwater plumes indicate that less than 30 meters of salt will be removed from the upper surfaces of the dome in 250,000 years. Thus, these preliminary studies show that even apparently unstable domes may be sufficiently stable to serve as waste disposal sites. 6 figures

Hydrologic environment of the Silurian salt deposits in parts of Michigan, Ohio, and New York

Science.gov (United States)

Norris, Stanley E.

1978-01-01

The aggregate thickness of evaporites (salt, gypsum, and anhydrite) in the Silurian Salina sequence in Michigan exceeds 1200 feet in areas near the periphery of the Michigan basin, where the salt beds are less than 3000 feet below land surface. In northeast Ohio the aggregate thickness of salt beds is as much as 200 feet in places, and in western New York it is more than 500 feet, where th beds are less than 3000 feet deep. The salt-bearing rocks dip regionally on the order of 50 feet per mile; those in Michigan dip toward the center of the Michigan basin, and those in Ohio and New York, in the Appalachian basin, dip generally southward. The rocks in both basins thicken downdip. Minor folds and faults occur in the salt-bearing rocks in all three states. Some of this defrmation has been attenuated or absorbed bo the salt beds. Occuring near the middle of thick sedimentary sequences, the salt beds are bounded aboe and below by beds containing water having dissolved-solids concentrations several times that seawter. The brines occur commonly in discrete zones of high permeability at specific places in the stratigraphic sequence. In northeast Ohio two prominent brine zones are recognized by the driller, the Devonian Oriskany Sandstone, or 'first water' zone, above the Salina Formation, and the Newburg or 'second water' zone below the Salina. In each aquifer there is a vertical component of hydraulic head, but little brine probably moves through the salt beds because their permeability is extremely low. Also, ther is little evidence of dissolution of the salt in areas distant from the outcrop, suggesting that if brine does move through the salt, movement is at a slow enough rate so that, in combination with the saturated or near-saturated condition of the water, it precludes significant dissolution. Principal brine movement is probably in the permeable zones in the direction of the hydraulic gradient. Two areas in Michigan and one area each in Ohio and New York appear

P-wave velocity structure beneath the northern Antarctic Peninsula: evidence of a steeply subducting slab and a deep-rooted low-velocity anomaly beneath the central Bransfield Basin

Science.gov (United States)

Park, Yongcheol; Kim, Kwang-Hee; Lee, Joohan; Yoo, Hyun Jae; Plasencia L., Milton P.

2012-12-01

Upper-mantle structure between 100 and 300 km depth below the northern Antarctic Peninsula is imaged by modelling P-wave traveltime residuals from teleseismic events recorded on the King Sejong Station (KSJ), the Argentinean/Italian stations (JUBA and ESPZ), an IRIS/GSN Station (PMSA) and the Seismic Experiment in Patagonia and Antarctica (SEPA) broad-band stations. For measuring traveltime residuals, we applied a multichannel cross-correlation method and inverted for upper-mantle structure using VanDecar's method. The new 3-D velocity model reveals a subducted slab with a ˜70° dip angle at 100-300 km depth and a strong low-velocity anomaly confined below the SE flank of the central Bransfield Basin. The low velocity is attributed to a thermal anomaly in the mantle that could be as large as 350-560 K and which is associated with high heat flow and volcanism in the central Bransfield Basin. The low-velocity zone imaged below the SE flank of the central Bransfield Basin does not extend under the northern Bransfield Basin, suggesting that the rifting process in that area likely involves different geodynamic processes.

Water resources in the Big Lost River Basin, south-central Idaho

Science.gov (United States)

Crosthwaite, E.G.; Thomas, C.A.; Dyer, K.L.

1970-01-01

The Big Lost River basin occupies about 1,400 square miles in south-central Idaho and drains to the Snake River Plain. The economy in the area is based on irrigation agriculture and stockraising. The basin is underlain by a diverse-assemblage of rocks which range, in age from Precambrian to Holocene. The assemblage is divided into five groups on the basis of their hydrologic characteristics. Carbonate rocks, noncarbonate rocks, cemented alluvial deposits, unconsolidated alluvial deposits, and basalt. The principal aquifer is unconsolidated alluvial fill that is several thousand feet thick in the main valley. The carbonate rocks are the major bedrock aquifer. They absorb a significant amount of precipitation and, in places, are very permeable as evidenced by large springs discharging from or near exposures of carbonate rocks. Only the alluvium, carbonate rock and locally the basalt yield significant amounts of water. A total of about 67,000 acres is irrigated with water diverted from the Big Lost River. The annual flow of the river is highly variable and water-supply deficiencies are common. About 1 out of every 2 years is considered a drought year. In the period 1955-68, about 175 irrigation wells were drilled to provide a supplemental water supply to land irrigated from the canal system and to irrigate an additional 8,500 acres of new land. Average. annual precipitation ranged from 8 inches on the valley floor to about 50 inches at some higher elevations during the base period 1944-68. The estimated water yield of the Big Lost River basin averaged 650 cfs (cubic feet per second) for the base period. Of this amount, 150 cfs was transpired by crops, 75 cfs left the basin as streamflow, and 425 cfs left as ground-water flow. A map of precipitation and estimated values of evapotranspiration were used to construct a water-yield map. A distinctive feature of the Big Lost River basin, is the large interchange of water from surface streams into the ground and from the

Determination of a constitutive law for salt at elevated temperature and pressure

International Nuclear Information System (INIS)

Senseny, P.E.

1985-01-01

A constitutive law for natural rock salt is given that describes the relationship among strain rate, stress rate, stress, temperature, and time. Tests required to evaluate the constitutive parameters are identified, and procedures for performing these tests are described. Results are presented from a series of tests performed on bedded salt from the Palo Duro basin. These results are used to evaluate the constitutive law suitable for predicting stresses and deformations in a nuclear waste repository or other engineered structure in salt

Investigation of Climate Change Impact on Salt Lake by Statistical Methods

Directory of Open Access Journals (Sweden)

Osman Orhan

2017-03-01

Full Text Available The main purpose of this paper is to investigate climate change impact that have been occurred on Salt Lake located in the central Anatolia is one of the area that has been faced to extinction. In order to monitor current status of the Salt Lake, Landsat satellite images has been obtained between the year of 2000 and 2014 (for the months of February, May, August and November. Satellite images has been processed by using ArcGIS and ERDAS softwares and the water surface area has been determined. The time series of water surface areas has been analyzed with auto-correlation method and repeated pattern has been detected. The seasonal part of the time series which period is 1 year and causes about 400 km² fluctuations has been removed with Moving Average filter, successfully. As a result of filtration process, non-seasonal time series of water surface area of Salt Lake were obtained. It is understood from the non-seasonal time series that the water surface area showed variability between 2000 and 2010 and after 2010 it is stable until 2014. In order to explain the variability, meteorological data (precipitation and temperature of the surrounding area has been acquired from the related service. The cross-correlation analyses has been performed with the movement of the water surface area and meteorological time series. As a result of analysis, the relationship between water surface changes in Salt Lake and meteorological data have correlated up to 80%. Consequently, several conclusion have been detected that the topography of the region play a direct role of the correlation coefficients and the water surface changes are effected from the environmental events that is occurred in the south of Salt Lake sub-Basin.

Long term spatial and temporal rainfall trends and homogeneity analysis in Wainganga basin, Central India

Directory of Open Access Journals (Sweden)

Arun Kumar Taxak

2014-08-01

Full Text Available Gridded rainfall data of 0.5×0.5° resolution (CRU TS 3.21 was analysed to study long term spatial and temporal trends on annual and seasonal scales in Wainganga river basin located in Central India during 1901–2012. After testing the presence of autocorrelation, Mann–Kendall (Modified Mann–Kendall test was applied to non-auto correlated (auto correlated series to detect the trends in rainfall data. Theil and Sen׳s slope estimator test was used for finding the magnitude of change over a time period. For detecting the most probable change year, Pettitt–Mann–Whitney test was applied. The Rainfall series was then divided into two partial duration series for finding changes in trends before and after the change year. Arc GIS was used to explore spatial patterns of the trends over the entire basin. Though most of the grid points shows a decreasing trend in annual rainfall, only seven grids has a significant decreasing trend during 1901–2012. On the basis of seasonal trend analysis, non-significant increasing trend is observed only in post monsoon season while seven grid points show significant decreasing trend in monsoon rainfall and non-significant in pre-monsoon and winter rainfall over the last 112 years. During the study period, overall a 8.45% decrease in annual rainfall is estimated. The most probable year of change was found to be 1948 in annual and monsoonal rainfall. There is an increasing rainfall trend in the basin during the period 1901–1948, which is reversed during the period 1949–2012 resulting in decreasing rainfall trend in the basin. Homogeneous trends in annual and seasonal rainfall over a grid points is exhibited in the basin by van Belle and Hughes׳ homogeneity trend test.

Summary report on salt dissolution review meeting, March 29--30, 1977

International Nuclear Information System (INIS)

Johnson, K.S.; Brokaw, A.L.; Gilbert, J.F.; Saberian, A.; Snow, R.H.; Walters, R.F.

1977-01-01

It is the unanimous conclusion of the Ad Hoc Committee that radioactive waste can be stored in salt and underground repository sites sufficiently removed from natural and/or man-made dissolution areas so that the waste will not be liberated during its hazardous period at projected rates of future salt dissolution. To ensure long-term isolation of radioactive waste in salt formations, specific recommendations are given for needed research concerning (A) General Principles, (B) Basinal or Regional Studies, and (C) Site-Specific Studies, each stated in sequence of priority

Permian and Triassic microfloral assemblages from the Blue Nile Basin, central Ethiopia

Science.gov (United States)

Dawit, Enkurie L.

2014-11-01

Palynological investigation was carried out on surface samples from up to 400 m thick continental siliciclastic sediments, here referred to as “Fincha Sandstone”, in the Blue Nile Basin, central Ethiopia. One hundred sixty species were identified from 15 productive samples collected along a continuous road-cut exposure. Six informal palynological assemblage zones have been identified. These assemblage zones, in ascending order, are: “Central Ethiopian Permian Assemblage Zone - CEPAZ I”, earliest Permian (Asselian-Sakmarian); “CEPAZ II”, late Early Permian (Artinskian-Kungurian); CEPAZ III - Late Permian (Kazanian-Tatarian); “CETAZ IV”, Lower Triassic (Olenekian Induan); “CETAZ V”, Middle Triassic (Anisian Ladinian); “CETAZ VI”, Late Triassic (Carnian Norian). Tentative age ranges proposed herein are compared with faunally calibrated palynological zones in Gondwana. The overall composition and vertical distribution of miospores throughout the studied section reveals a wide variation both qualitatively and quantitatively. The high frequency of monosaccate pollen in CEPAZ I may reflect a Glossopterid-dominated upland flora in the earliest Permian. The succeeding zone is dominated by straite/taeniate disaccate pollen and polyplicates, suggesting a notable increase in diversity of glossopterids. The decline in the diversity of taeniate disaccate pollen and the concomitant rise in abundance of non-taeniate disaccates in CEPAZ III may suggest the decline in Glossopteris diversity, though no additional evidence is available to equate this change with End-Permian extinction. More diverse and dominant non-taeniate, disaccate, seed fern pollen assignable to FalcisporitesAlisporites in CETAZ IV may represent an earliest Triassic recovery flora. The introduction of new disaccate forms with thick, rigid sacci, such as Staurosaccites and Cuneatisporites, in CETAZ V and VI may indicate the emergence of new gymnospermous plants that might have favourably

Geological status of NWTS repository siting activities in the paradox basin

International Nuclear Information System (INIS)

Frazier, N.A.; Conwell, F.R.

1981-01-01

Emplacement of waste packages in mined geological repositories is one method being evaluated for isolating high-level nuclear wastes. Granite, dome salt, tuff, basalt and bedded salt are among the rock types being investigated. Described in this paper is the status of geological activities in the Paradox Basin of Utah and Colorado, one region being explored as a part of the National Waste Terminal Storage (NWTS) program to site a geological repository in bedded salt

What's next? Lesser explored basins : offshore Newfoundland and Labrador

Energy Technology Data Exchange (ETDEWEB)

Wright, J.A. [Memorial Univ. of Newfoundland, St. John' s, NL (Canada). Dept. of Earth Sciences

2005-07-01

A review of the sedimentary basins of Atlantic Canada was presented with particular focus on offshore basins in the southern Grand Banks, the Gulf of St. Lawrence and the Labrador Shelf. The exploration history and petroleum geology of the South Whale Basin in southern Grand Banks was discussed with reference to salt diapirism, salt tectonism and gas prone source rocks. Early exploration of the Anticosti and Magdalen Basins, 2 basins in the Gulf of St. Lawrence, revealed a proven petroleum system. However, there has been very limited modern exploration in the area. A detailed geologic review of Appalachian Ordovician carbonate producers was also presented. The early exploration phase of the Labrador Shelf from 1975 to 1982 confirmed a petroleum system. However, the discoveries offered poor economics due to the high cost of recovery. Five gas discoveries in the Hopedale Basin in Labrador were made in the early 1970s, with an estimated development threshold of 6 to 7 Tcf marketable gas reserves. A new outlook for the Labrador Shelf has been provided due to new and extensive seismic data, multiple play concepts, gas takeaway systems such as marine CNG, and strong economics for more than 8 Tcf of gas reserves. It was concluded that 3 new basins with proven petroleum systems in Atlantic Canada are both accessible and close to markets. figs.

Kinematic reconstitution and tectono-sedimentation associated to salt domes in deep water of Santos basin, Brazil; Reconstituicao cinematica e tectono-sedimentacao associada a domos salinos nas aguas profundas da bacia de Santos, Brasil

Energy Technology Data Exchange (ETDEWEB)

Caldas, Manuela Fernandes [PETROBRAS E e P - Exploracao, Rio de Janeiro, RJ (Brazil). Polo Centro], E-mail: manuela.caldas@petrobras.com.br; Zalan, Pedro Victor [PETROBRAS E e P - Exploracao, Rio de Janeiro, RJ (Brazil). Gestao de Projetos Exploratorios], E-mail: zalan@petrobras.com.br

2009-05-15

This article presents new methods for structural restoration and kinematic evolution of salt domes during the opening stages and growth of a passive margin in the Santos Basin. The traditional method or restoration of salt bodies uses software and a 3D database. Using 2D seismic data and adapting/improving methods published in the oil industry literature, we developed a method based on the observation of the stratal geometric patterns of sedimentary packages associated to the salt bodies such as tabular forms (straight parallel reflectors, pre or post-tectonic sedimentary sequences), or dish/bowl forms (with very distinct depocenters and thinned margins with fanning of dips, syntectonic/halokinetic sedimentary sequences), and on the determination/mapping of growth axes and thinning axes in halokinetic strata. Horizontal and vertical reconstitutions of the salt flow (inflation, deflation and horizontal flow) were deduced based on isochron (isopach maps in time) and axes maps and flattened seismic sections at the time of deposition of each associated sedimentary sequence. The resulting maps and reconstitutions presented an amazing correlation with the current patterns mapped in the study area. The interpreted tectonic phases of halokinetic evolution, deduced from the produced maps and reconstitutions, showed a good agreement with the regional events that affected the Santos Basin and adjoining basement. Based on those results, we believe that the application of this method provides an important contribution for the oil exploration industry, considering that it presents outstanding results based on 2D seismic data. It allows an understanding of the structural and kinematic evolution of the salt bodies and of the halokinetic sequences associated, with important implications on the modeling of petroleum systems, thus, reducing the risk of exploration prospects. (author)

Geophysical Well-Log Measurements in Three Drill Holes at Salt Valley, Utah

OpenAIRE

Daniels, Jeffrey J.; Hite, Robert J.; Scott, James H.; U.S. Geological Survey

1980-01-01

Three exploratory drill holes were drilled at Salt Valley, Utah, to study the geologic, physical, geochemical, and hydrologic properties of the evaporite sequence in the Permian Paradox Member of the Hermosa Formation. The results of these studies will be used to help to determine the suitability of salt deposits in the Paradox basin as a storage medium for radioactive waste material.

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

High pollution events in the Great Salt Lake Basin and its adjacent valleys. Insights on mechanisms and spatial distribution of the formation of secondary aerosol.

Science.gov (United States)

Franchin, A.; Middlebrook, A. M.; Baasandorj, M.; Brown, S. S.; Fibiger, D. L.; Goldberger, L.; McDuffie, E. E.; Moravek, A.; Murphy, J. G.; Thornton, J. A.; Womack, C.

2017-12-01

High pollution events are common in many locations in the U.S.A. and around the world. They can last several days or up to weeks and they negatively affect human health, deteriorate visibility, and increase premature mortality. The main causes for high pollution events are related to meteorology and sources. They often happen in the winter, when high emissions, stagnation and reduced mixing, due to a shallow boundary layer, cause high concentrations of pollutants to accumulate. In the last decades, the air quality in the U.S. has seen an overall improvement, due to the reductions in particulate and gaseous pollutants. However, some areas remain critical. The Great Salt Lake Basin and its adjacent valleys are currently areas where high pollution events are a serious environmental problem involving more than 2.4 million people. We will present the results of the Utah Wintertime Fine Particulate Study (UWFPS) that took place in winter 2017. During UWFPS, we carried out airborne measurements of aerosol chemical composition and precursor vapor concentrations over the Great Salt Lake Basin and its adjacent valleys. We will give insights into how and under which conditions conversion of precursor vapors into aerosol particles takes place in the area. We will also present a comparison of our measurements with models that will provide an insight of the mechanisms that lead to the formation of secondary aerosol particles. With the results of our work, we aim to inform strategies for pollution control in the future.

Temperature profiles from Salt Valley, Utah

Science.gov (United States)

Sass, J. H.; Lachenbruch, A. H.; Smith, E. P.

Temperature profiles were obtained in the nine drilled wells as part of a thermal study of the Salt Valley anticline, Paradox Basin, Utha. Thermal conductivities were also measured on 10 samples judged to be representative of the rocks encountered in the deepest hole. The temperature profiles and thermal conductivities are presented, together with preliminary interpretive remarks and suggestions for additional work.

Seismic-refraction survey to the top of salt in the north end of the Salt Valley Anticline, Grand County, Utah

Science.gov (United States)

Ackermann, Hans D.

1979-01-01

A seismic-refraction survey, consisting of three lines about 2700, 2760, and 5460 meters long, was made at the north end of the Salt Valley anticline of the Paradox Basin in eastern Utah. The target was the crest of a diapiric salt mass and the overlying, deformed caprock. The interpretations reveal an undulating salt surface with as much as 80 meters of relief. The minimum depth of about 165 meters is near the location of three holes drilled by the U.S. Department of Energy for the purpose of evaluating the Salt Valley anticline as a potential site for radioactive waste storages Caprock properties were difficult to estimate because the contorted nature of these beds invalidated a geologic interpretation in terms of velocity layers. However, laterally varying velocities of the critically refracted rays throughout the area suggest differences in the gross physical properties of the caprock.

Seismic-refraction survey to the top of salt in the north end of the Salt valley anticline, Grand County, Utah

International Nuclear Information System (INIS)

Achermann, H.D.

1979-01-01

A sesimic-refraction survey, consisting of three lines about 2700, 2760, and 5460 meters long, was made at the north end of the Salt valley anticline of the Paradox Basin in eastern Utah. The target was the crest of a diapiric salt mass and the overlying, deformed caprock. The interpretations reveal an undulating salt surface with as much as 80 meters of relief. The minimum depth of about 165 meters is near the location of three holes drilled by the US Department of Energy for the purpose of evaluating the Salt Valley anticline as a potential site for radioactive waste storage. Caprock properties were difficult to estimate because the contorted nature of these beds invalidated a goelogic interpretation in terms of velocity layers. However, laterally varying velocities of the critically refracted rays throughout the area suggest differences in the gross physical properties of the caprock

Spatial and Temporal Strain Distribution Along the Central Red Sea Rift - A Study of the Hamd-Jizil Basin in Saudi Arabia

Science.gov (United States)

Szymanski, E.; Stockli, D.; Johnson, P.; Kattan, F. H.; Al Shamari, A.

2006-12-01

Numerous models exploring the rupturing modes and mechanisms of continental lithosphere are based on geological evidence from the Red Sea/Gulf of Suez rift system. Individually, the Red Sea basin is the prototype for many models of orthogonal continental rifting. Despite being a classic example of continental extension, many temporal and spatial strain distribution aspects, as well as the dynamic evolution of the rift architecture of the Red Sea, remain poorly constrained. Critical data come mostly from the Gulf of Suez and the Egyptian and Yemeni margins of the Red Sea; the rift flanks in Sudan and Saudi Arabia have remained largely unstudied, leaving a large information gap along the central portions of the rift system. Improving continental lithosphere rupture models requires an absolute understanding of the timing and magnitude of strain partitioning along the full rift flank. This study focuses on the development of extensional structures, syn- extensional sedimentary deposits, and rift-related Tertiary basaltic volcanism along the central flank of the rift system in Saudi Arabia. Geo- and thermochronometric techniques are used to elucidate the evolution of inboard and outboard strain markers manifested by structurally-controlled extensional basins that parallel the trend of the main Red Sea rift. Constraints on the dynamics of rift flank deformation are achieved through the collection of thermochronometric transects that traverse both the entire Arabian shield and individual normal faults that bound inland basins. Preliminary results show inland basins as asymmetric half-grabens filled by tilted Cenozoic sedimentary strata and separated by exhumed basement fault blocks. The most prominent extensional basin is the NW-trending Hamd-Jizil basin, located north of Madinah, measuring ~200 km along strike and up to 20 km in width. The Hamd-Jizil basin is structurally characterized by two half-grabens exposing a series of syn-rift siliciclastic sedimentary sections

Evidence of sealing and brine distribution at grain boundaries in natural fine-grained Halite (Qum Kuh salt fountain, Central Iran): implications for rheology of salt extrusions

Science.gov (United States)

Desbois, Guillaume; Urai, Janos L.; de Bresser, J. H. P.

2010-05-01

When grain boundary movement is stopped, surface energy related forces reassert themselves driving the system to its equilibrium conditions ([2], [6], [7], [8]). This could result in growth of islands and shrinking of channels and hence in healing the boundary by internal redistribution of fluid and solid in the contact region. Such islands are proposed to grow preferentially close to the contact rim and promote the healing of the grain-grain contact, which in turn prevents transport in or out the boundary region and thus traps the fluids in isolated inclusions. This contribution is focused on observation of grain boundary microstructures in natural mylonitic rocksalt collected from the distal part of Kum-Quh salt fountain (central Iran) in order to give unprecedented insight of grain boundary microstructures using argon-beam cross-sectioning to prepare high quality polished surfaces suitable for high-resolution SEM imaging. The possibility to use our SEM under cryogenic conditions allows also imaging the in-situ distribution of fluids. Results show that brine at grain boundaries occurs as thick layers (> µm in scale) corresponding to cross-sectioned wetted triple junction tubes, as filling at triple junction and as array of isolated fluids inclusions at grain-grain contacts. Close observations at islands contacts suggest the presence of a very thin fluid film (Journal of Structural Geology. [2] Ghoussoub J., and Leroy Y.M. (2001), Solid-fluid phase transformation within grain boundaries during compaction by pressure solution, J. Mech. Phys. Solids, 49, 737 2385-2430. 738 [3] Jackson, M.P.A., (1985). Natural strain in diapiric and glacial rock salt, with emphasis on Oakwood dome, East Texas, Bureau of Economic Geology, The University of Texas at Austin, Texas. [4] Schléder Z. and Urai J.L. (2007). Deformation and recrystallization mechanisms in mylonitic shear zones in naturally deformed extrusive Eocene-Oligocene rock salt from Eyvanekey plateau and Garmsar

Amount and nature of occluded water in bedded salt, Palo Duro Basin, Texas

International Nuclear Information System (INIS)

Fisher, R.S.

1987-01-01

The quantity and types of fluids within bedded salt cores from the Permian San Andres Formation, Palo Duro, Texas, were evaluated at the Texas Bureau of Economic Geology. Bedded halite from the San Andres Formation and other salt-bearing units were selected to represent the variety of salt types present, and were then analyzed. The mean water content of ''pure'' samples (more than 90% halite) is 0.4 weight percent, with none observed greater than 1.0 weight percent. Samples that contain more than 10 weight percent clay or mudstone display a trend of increasing water content with increasing clastic material. Chaotic mudstone-halite samples have as much as 5 weight percent water; halite-cemented mudstone interlayers, common throughout the bedded salts, may have water content values as high as 10 to 15 weight percent based on extrapolation of existing data that range from 0 to about 6%. No significant difference exists between the mean water content values of ''pure salt'' from the upper San Andres, lower San Andres Cycle 5, and lower San Andres Cycle 4 salt units. The fraction of total water present as mobile intergranular water is highly variable and not readily predicted from observed properties of the salt sample. The amount of water that would be affected by a high-level nuclear waste repository can be estimated if the volume of halite, the volume of clastic interlayers, and the amount and type of impurity in halite are known. Appendix contains seven vugraphs

Evolution and timing of salt diapirism in the Iranian sector of the Persian Gulf

Science.gov (United States)

Perotti, Cesare; Chiariotti, Luca; Bresciani, Ilenia; Cattaneo, Luciano; Toscani, Giovanni

2016-06-01

The Iranian sector of the Persian Gulf is affected by more than 30 large diapiric structures triggered by the mobilization of the Infracambrian Hormuz Complex, an evaporite-rich unit that overlies Precambrian basement at the base of the sedimentary succession. Nineteen non-piercing diapirs, without any appreciable salt intrusion into the upper succession, were studied in detail and retro-deformed by the decompaction and unfolding of 13 seismic horizons that were identified by the interpretation of a dense grid of 2D seismic lines and calibrated by well data. Salt uplift had begun by the Early Palaeozoic and persists to the present day, with major pulses of intensity during the Middle Triassic, Cenomanian, Late Oligocene, and post-Middle Miocene. The structural reconstructions and the analysis of the progressive deformation of the study diapirs do not show any link between diapiric uplift and local tectonic structures, and no clear correlation with the regional geodynamic events acting at the boundary of the Arabian plate. On the contrary, the salt uplift seems strongly influenced by the differential rate of sedimentation that affected the whole study basin (more than 40,000 km2), with a coefficient of correlation between the salt uplift rate and the differential rate of sedimentation (expressed by the standard deviation of the sedimentation rate calculated over the entire basin) of 0.95. This downbuilding mechanism of diapiric growth is apparently induced by differential sedimentation over long distances (several tens of kilometers), showing that the flow of salt affected the whole basin and not just the areas around the single diapiric structures.

The "DREAM" IODP project to drill the Mediterranean Salt Giant on the Balearic Promontory

Science.gov (United States)

Lofi, Johanna; Camerlenghi, Angelo; Aloisi, Giovanni; Maillard, Agnès; Garcia-Castellanos, Daniel; Huebscher, Christian; Kuroda, Junichiro

2017-04-01

Salt giants preserving kilometer-thick evaporite layers are the sedimentary expression of extreme environmental events of global relevance. Despite their global occurrence and general importance on Earth, there is currently no complete stratigraphic record through an un-deformed salt giant of marine origin. Similarly, there is a significant lack of knowledge about the factors controlling salt giants deposition, their early evolution, the impact they exert on the isostatic response of continental margins and on sub-salt formations, and the unprecedented deep biosphere they may harbor. The Mediterranean Messinian salt giant, which formed 5.5 Myrs ago, is one of the youngest salt giant on Earth and is currently lying below the Plio-Quaternary cover in a relatively un-deformed state close to its original depositional configuration. This salt giant is thus accessible by drilling and forms an ideal case study that could be used as a reference for older salt giants. However, since its discovery in 1970 during the DSDP Leg XIII, and despite 40 years or multi-disciplinary researches, this salt giant is still not fully understood and remains one of the longest-living controversies in Earth Science. In this context, the IODP DREAM project aims at exploring the Mediterranean salt giant by drilling with the JOIDES Resolution a transect of 4 sites on the southern margin of the Balearic promontory (Western Mediterranean). We identified this area as likely the only place in the Mediterranean where we could implement a shallow-to-deep transect of non-riser drilling sites. Due to the geological history and pre-structuration of the Promontory, MSC deposits are found preserved in a series of sedimentary basins lying at different water depths between the present-day coastline and the deep central salt basins. DREAM thus offers a unique opportunity to sample several hundred of meters of material forming the Mediterranean salt giant in varied water depths. This unique sedimentary record

The impacts of mega discoveries of oil and natural gas in the pre-salt Santos Basin: Brazil 2000 - 2030 - 2050; Os impactos das mega descobertas de oleo e gas natural no pre-sal da Bacia de Santos: Brasil 2000 - 2030 - 2050

Energy Technology Data Exchange (ETDEWEB)

Bahia, Raymundo Ruy; Reis, Lucio Eduardo Solano [Universidade da Amazonia (GEPEE/UNAMA), Belem, PA (Brazil). Nucleo de Socio-economia. Grupo de Estudos e Pesquisas Economicas Energeticas], e-mail: ruybahia@uol.com.br, e-mail: lereis2000@gmail.com

2008-07-01

This paper is a follow-up of four papers presented at the V CBPE 2006 e XI CBE 2006 updating the investment needs to expand the electric energy (EE) Offer. Such analysis revealed an hydro matrix over cost investments of 293 bi US$ (10bi US$/year) as compared to the hydro thermo matrix. Such data proof the unviability to supply the Southern, Southeastern and Central-West regions demand with Amazonian hydroelectricity. Furthermore, evaluations about the impacts of the huge underestimate volumes of proved reserves of oil and NG of 20 Gboe from the Projects Tupi, Carioca and Parati and Jupiter discoveries are limited to a small geographic area of 15,000 sqkm (122 x 122 km) that is only 9 percent of the Pre-Salt total area of 160,000 sqkm supporting the hypothesis of 160 Gboe for the ultimate ROR for both Campos and Pre-Salt Basins plus all others exploratory fronts offshore and onshore. In this probable case the mid-points of oil and NG will migrate to the 2070 year. Under these circumstances either scenarios will support the oil and NG self-sufficiencies for those regions Southern, Southeastern and Central-West regions, up to the 2050 year and probably extended to the 2070 year. The estimated volume of the potential proved reserve NG Jupiter Project is also underestimate but large enough (7,0 Gboe = 1,100 billion of cubic meter= Gmc) to supply 80 percent (80 GW) of the total 101 GW expansion offer of EE up to the 2030 year. Finally there is not a single good reason to justify the supply the EE demand of the Southern, Southeastern and Central-West regions with the unviable Amazonian hydroelectricity. (author)

Hydrogeological framework and geometry modeling via joint gravity and borehole parameters, the Nadhour-Sisseb-El Alem basin (central-eastern Tunisia)

Science.gov (United States)

Souei, Ali; Atawa, Mohamed; Zouaghi, Taher

2018-03-01

The Nadhour-Sisseb-El Alem basin, in the central-eastern part of Tunisia, is characterized by the scarcity of surface and subsurface water resources. Although the aquifer systems of this basin are not well understood, the scarce water resources are subject to a high rate of exploitation leading to a significant drop in the level of the water table. This work presents correlation of gravity data with hydrogeological data in order to improve the knowledge of the deep structures and aquifer systems. Various geophysical filtering techniques (e.g., residual anomaly, upward continuation, horizontal gradient, and Euler deconvolution) applied to the complete Bouguer anomaly, deduce the deep structures and geometry of the basin and highlight gravity lineaments that correspond to the tectonic features. The structural framework of the Nadhour-Sisseb-El Alem hydrogeological basin shows N-S to NNE-SSW and E-W oriented structures that should be related to tectonic deformations. In addition to the faults, previously recognized, new lineaments are highlighted by the present work. They correspond to NE-, NW-, E- and N- trending faults that have controlled structuring and geometry of the basin. 2D gravity forward modeling, based on the interpretation of geophysical, geological and hydrogeological data, led to a better understanding of the basin geometry and spatial distribution of the Campanian-Maastrichtian and Cenozoic potential aquifers. Three hydrogeological sub-basins identified include the Nadhour sub-basin in the north, the El Alem sub-Basin in the South and the Etrabelsia sub-Basin in the East. These sub-basins are marked by a thickening of deposits, are separated by the Sisseb-Fadeloun raised structure of Neogene and Quaternary thinned series. The results allow the determination of limit conditions for the basin hydrodynamic evolution and explain some anomalies on the quantity and quality of the groundwater. They provide a management guide for water resources prospection in

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

An integrated framework to assess adaptation options to climate change impacts in an irrigated basin in Central North Chile

Science.gov (United States)

Vicuna, S.; Melo, O.; Meza, F. J.; Alvarez, P.; Maureira, F.; Sanchez, A.; Tapia, A.; Cortes, M.; Dale, L. L.

2013-12-01

Future climate conditions could potentially affect water supply and demand on water basins throughout the world but especially on snowmelt-driven agriculture oriented basins that can be found throughout central Chile. Increasing temperature and reducing precipitation will affect both the magnitude and timing of water supply this part of the world. Different adaptation strategies could be implemented to reduce the impacts of such scenarios. Some could be incorporated as planned policies decided at the basin or Water Use Organization levels. Examples include changing large scale irrigation infrastructure (reservoirs and main channels) either physically or its operation. Complementing these strategies it is reasonable to think that at a disaggregated level, farmers would also react (adapt) to these new conditions using a mix of options to either modify their patterns of consumption (irrigation efficiency, crop mix, crop area reduction), increase their ability to access new sources of water (groundwater, water markets) or finally compensate their expected losses (insurance). We present a modeling framework developed to represent these issues using as a case study the Limarí basin located in Central Chile. This basin is a renowned example of how the development of reservoirs and irrigation infrastructure can reduce climate vulnerabilities allowing the economic development of a basin. Farmers in this basin tackle climate variability by adopting different strategies that depend first on the reservoir water volume allocation rule, on the type and size of investment they have at their farms and finally their potential access to water markets and other water supplies options. The framework developed can be used to study these strategies under current and future climate scenarios. The cornerstone of the framework is an hydrology and water resources model developed on the WEAP platform. This model is able to reproduce the large scale hydrologic features of the basin such as

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

Directory of Open Access Journals (Sweden)

J. GABRIEL PENDÓN

2004-07-01

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

Estimates of ground-water recharge rates for two small basins in central Nevada

Science.gov (United States)

Lichty, R.W.; McKinley, P.W.

1995-01-01

Estimates of ground-water recharge rates developed from hydrologic modeling studies are presented for 3-Springs and East Stewart basins. two small basins (analog sites) located in central Nevada. The analog-site studies were conducted to aid in the estimation of recharge to the paleohydrologic regime associated with ground water in the vicinity of Yucca Mountain under wetter climatic conditions. The two analog sites are located to the north and at higher elevations than Yucca Mountain, and the prevailing (current) climatic conditions at these sites is thought to be representative of the possible range of paleoclimatic conditions in the general area of Yucca Mountain during the Quaternary. Two independent modeling approaches were conducted at each of the analog sites using observed hydrologic data on precipitation, temperature, solar radiation stream discharge, and chloride-ion water chemistry for a 6-year study period (October 1986 through September 1992). Both models quantify the hydrologic water-balance equation and yield estimates of ground-water recharge, given appropriate input data. The first model uses a traditional approach to quantify watershed hydrology through a precipitation-runoff modeling system that accounts for the spatial variability of hydrologic inputs, processes, and responses (outputs) using a dailycomputational time step. The second model is based on the conservative nature of the dissolved chloride ion in selected hydrologic environments, and its use as a natural tracer allows the computation of acoupled, water and chloride-ion, mass-balance system of equations to estimate available water (sum ofsurface runoff and groundwater recharge). Results of the modeling approaches support the conclusion that reasonable estimates of average-annual recharge to ground water range from about 1 to 3 centimeters per year for 3-Springs basin (the drier site), and from about 30 to 32 centimeters per year for East Stewart basin (the wetter site). The most

Effect of diagenesis on pore pressures in fine-grained rocks in the Egersund Basin, Central North Sea

OpenAIRE

Kalani, Mohsen; Zadeh, Mohammad Koochak; Jahren, Jens; Mondol, Nazmul Haque; Faleide, Jan Inge

2015-01-01

- Pore pressure in fine-grained rocks is important with respect to drilling problems such as kicks, blowouts, borehole instability, stuck pipe and lost circulation. In this study, a succession of overpressured, fine-grained, sedimentary rocks located in the Egersund Basin, Central North Sea, was analysed with respect to mineralogical composition, source-rock maturation and log-derived petrophysical properties to highlight the effect of diagenetic processes on the pore pressure. Pe...

Chemical implications of heat and radiation damage to rock salt

International Nuclear Information System (INIS)

Pederson, L.R.

1984-11-01

Chemical changes induced in Palo Duro and Paradox Basin natural rock salts and in synthetic NaCl by heat and gamma radiation were investigated. Heating of unirradiated natural rock salts to 300 0 C resulted in HCl (most prevalent), SO 2 , CO 2 , and H 2 S evolution, and increased the base content of the remaining salt by not more than 10 microequivalents per gram; whereas, heating of synthetic NaCl gave no product. Gamma irradiation produced sodium colloids and neutral chlorine in amounts similar to the results of Levy and coworkers. When the irradiated salts were heated, three reactions were apparent: (1) radiation-induced defects recombined; (2) neutral chlorine was evolved; and (3) HCl, SO 2 , CO 2 , and H 2 S were evolved, similar to results for unirradiated salts. Because reaction (1) appeared to dominate over reaction (2), it is expected that the influence of radiation damage to salt on the near-field chemical environment will be minor. 4 figures, 1 table

Salt anticlines in the Castile-Salado evaporite sequence, northern Delaware Basin, New Mexico

International Nuclear Information System (INIS)

Anderson, R.Y.; Powers, D.W.

1977-01-01

Anticlines are more common around basin margin but are present in basin-center areas. Both Halite I and Halite II may have flowed but Halite I was movement more extensive. Depressions associated with anticlines may be due to either flowage or subsequent dissolution. Association with brine flows is common. Anticline probably was formed with mid-Cenozoic uplift and tilting of basin and with adjustments around reef margin

Biological productivity, terrigenous influence and noncrustal elements supply to the Central Indian Ocean Basin: Paleoceanography during the past approx. 1 Ma

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Masuzawa, T.; Borole, D.V.; Parthiban, G.; Jauhari, P.; Yamamoto, M.

A 2 m-long sediment core from the siliceous ooze domain in the Central Indian Ocean Basin (CIOB; 13 degrees 03'S: 74 degrees 44'E; water depth 5099 m) is studied for calcium carbonate, total organic carbon, total nitrogen, biogenic opal, major...

Nature, distribution and origin of clay minerals in grain size fractions of sediments from manganese nodule field, Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P.; Nath, B.N.

DT, IR and X-ray diffraction analyses have been carried out on 3 grain size fractions (1, 1-2 and 2-4 mu m) of sediments from the Central Indian Ocean Basin. Results indicate that there are 2 smectite minerals (montmorillonite and Fe...

Geohydrology of the Aucilla-Suwannee-Ochlockonee River Basin, south-central Georgia and adjacent parts of Florida

Science.gov (United States)

Torak, Lynn J.; Painter, Jaime A.; Peck, Michael F.

2010-01-01

Major streams and tributaries located in the Aucilla-Suwannee-Ochlockonee (ASO) River Basin of south-central Georgia and adjacent parts of Florida drain about 8,000 square miles of a layered sequence of clastic and carbonate sediments and carbonate Coastal Plain sediments consisting of the surficial aquifer system, upper semiconfining unit, Upper Floridan aquifer, and lower confining unit. Streams either flow directly on late-middle Eocene to Oligocene karst limestone or carve a dendritic drainage pattern into overlying Miocene to Holocene sand, silt, and clay, facilitating water exchange and hydraulic connection with geohydrologic units. Geologic structures operating in the ASO River Basin through time control sedimentation and influence geohydrology and water exchange between geohydrologic units and surface water. More than 300 feet (ft) of clastic sediments overlie the Upper Floridan aquifer in the Gulf Trough-Apalachicola Embayment, a broad area extending from the southwest to the northeast through the center of the basin. These clastic sediments limit hydraulic connection and water exchange between the Upper Floridan aquifer, the surficial aquifer system, and surface water. Accumulation of more than 350 ft of low-permeability sediments in the Southeast Georgia Embayment and Suwannee Strait hydraulically isolates the Upper Floridan aquifer from land-surface hydrologic processes in the Okefenokee Basin physiographic district. Burial of limestone beneath thick clastic overburden in these areas virtually eliminates karst processes, resulting in low aquifer hydraulic conductivity and storage coefficient despite an aquifer thickness of more than 900 ft. Conversely, uplift and faulting associated with regional tectonics and the northern extension of the Peninsular Arch caused thinning and erosion of clastic sediments overlying the Upper Floridan aquifer southeast of the Gulf Trough-Apalachicola Embayment near the Florida-Georgia State line. Limestone dissolution in

Mechanical modeling of the growth of salt structures

Energy Technology Data Exchange (ETDEWEB)

Alfaro, Ruben Alberto Mazariegos [Texas A & M Univ., College Station, TX (United States)

1993-05-01

A 2D numerical model for studying the morphology and history of salt structures by way of computer simulations is presented. The model is based on conservation laws for physical systems, a fluid marker equation to keep track of the salt/sediments interface, and two constitutive laws for rocksalt. When buoyancy alone is considered, the fluid-assisted diffusion model predicts evolution of salt structures 2.5 times faster than the power-law creep model. Both rheological laws predict strain rates of the order of 4.0 x 10^-15 s^-1 for similar structural maturity level of salt structures. Equivalent stresses and viscosities predicted by the fluid-assisted diffusion law are 10² times smaller than those predicted by the power-law creep rheology. Use of East Texas Basin sedimentation rates and power-law creep rheology indicate that differential loading is an effective mechanism to induce perturbations that amplify and evolve to mature salt structures, similar to those observed under natural geological conditions.

The Younger Dryas phase of Great Salt Lake, Utah, USA

Science.gov (United States)

Oviatt, Charles G.; Miller, D.M.; McGeehin, J.P.; Zachary, C.; Mahan, S.

2005-01-01

Field investigations at the Public Shooting Grounds (a wildlife-management area on the northeastern shore of Great Salt Lake) and radiocarbon dating show that the Great Salt Lake rose to the Gilbert shoreline sometime between 12.9 and 11.2 cal ka. We interpret a ripple-laminated sand unit exposed at the Public Shooting Grounds, and dated to this time interval, as the nearshore sediments of Great Salt Lake deposited during the formation of the Gilbert shoreline. The ripple-laminated sand is overlain by channel-fill deposits that overlap in age (11.9-11.2 cal ka) with the sand, and by wetland deposits (11.1 to 10.5 cal ka). Consistent accelerator mass spectrometry radiocarbon ages were obtained from samples of plant fragments, including those of emergent aquatic plants, but mollusk shells from spring and marsh deposits yielded anomalously old ages, probably because of a variable radiocarbon reservoir effect. The Bonneville basin was effectively wet during at least part of the Younger Dryas global-cooling interval, however, conflicting results from some Great Basin locations and proxy records indicate that the regional effects of Younger Dryas cooling are still not well understood. ?? 2005 Elsevier B.V. All rights reserved.

The Lower Triassic Sorkh Shale Formation of the Tabas Block, east central Iran: Succesion of a failed-rift basin at the Paleotethys margin

Science.gov (United States)

Lasemi, Y.; Ghomashi, M.; Amin-Rasouli, H.; Kheradmand, A.

2008-01-01

The Lower Triassic Sorkh Shale Formation is a dominantly red colored marginal marine succession deposited in the north-south trending Tabas Basin of east central Iran. It is correlated with the unconformity-bounded lower limestone member of the Elika Formation of the Alborz Mountains of northern Iran. The Sorkh Shale is bounded by the pre-Triassic and post-Lower Triassic interregional unconformities and consists mainly of carbonates, sandstones, and evaporites with shale being a minor constituent. Detailed facies analysis of the Sorkh Shale Formation resulted in recognition of several genetically linked peritidal facies that are grouped into restricted subtidal, carbonate tidal flat, siliciclastic tidal flat, coastal plain and continental evaporite facies associations. These were deposited in a low energy, storm-dominated inner-ramp setting with a very gentle slope that fringed the Tabas Block of east central Iran and passed northward (present-day coordinates) into deeper water facies of the Paleotethys passive margin of northern Cimmerian Continent. Numerous carbonate storm beds containing well-rounded intraclasts, ooids and bioclasts of mixed fauna are present in the Sorkh Shale Formation of the northern Tabas Basin. The constituents of the storm beds are absent in the fair weather peritidal facies of the Sorkh Shale Formation, but are present throughout the lower limestone member of the Elika Formation. The Tabas Block, a part of the Cimmerian continent in east central Iran, is a rift basin that developed during Early Ordovician-Silurian Paleotethys rifting. Facies and sequence stratigraphic analyses of the Sorkh Shale Formation has revealed additional evidence supporting the Tabas Block as a failed rift basin related to the Paleotethys passive margin. Absence of constituents of the storm beds in the fair weather peritidal facies of the Sorkh Shale Formation, presence of the constituents of the storm beds in the fair weather facies of the Elika Formation (the

Quantifying human impacts on hydrological drought using a combined modelling approach in a tropical river basin in central Vietnam

Directory of Open Access Journals (Sweden)

A. B. M. Firoz

2018-01-01

Full Text Available Hydrological droughts are one of the most damaging disasters in terms of economic loss in central Vietnam and other regions of South-east Asia, severely affecting agricultural production and drinking water supply. Their increasing frequency and severity can be attributed to extended dry spells and increasing water abstractions for e.g. irrigation and hydropower development to meet the demand of dynamic socioeconomic development. Based on hydro-climatic data for the period from 1980 to 2013 and reservoir operation data, the impacts of recent hydropower development and other alterations of the hydrological network on downstream streamflow and drought risk were assessed for a mesoscale basin of steep topography in central Vietnam, the Vu Gia Thu Bon (VGTB River basin. The Just Another Modelling System (JAMS/J2000 was calibrated for the VGTB River basin to simulate reservoir inflow and the naturalized discharge time series for the downstream gauging stations. The HEC-ResSim reservoir operation model simulated reservoir outflow from eight major hydropower stations as well as the reconstructed streamflow for the main river branches Vu Gia and Thu Bon. Drought duration, severity, and frequency were analysed for different timescales for the naturalized and reconstructed streamflow by applying the daily varying threshold method. Efficiency statistics for both models show good results. A strong impact of reservoir operation on downstream discharge at the daily, monthly, seasonal, and annual scales was detected for four discharge stations relevant for downstream water allocation. We found a stronger hydrological drought risk for the Vu Gia river supplying water to the city of Da Nang and large irrigation systems especially in the dry season. We conclude that the calibrated model set-up provides a valuable tool to quantify the different origins of drought to support cross-sectorial water management and planning in a suitable way to be transferred to similar

Quantifying human impacts on hydrological drought using a combined modelling approach in a tropical river basin in central Vietnam

Science.gov (United States)

Firoz, A. B. M.; Nauditt, Alexandra; Fink, Manfred; Ribbe, Lars

2018-01-01

Hydrological droughts are one of the most damaging disasters in terms of economic loss in central Vietnam and other regions of South-east Asia, severely affecting agricultural production and drinking water supply. Their increasing frequency and severity can be attributed to extended dry spells and increasing water abstractions for e.g. irrigation and hydropower development to meet the demand of dynamic socioeconomic development. Based on hydro-climatic data for the period from 1980 to 2013 and reservoir operation data, the impacts of recent hydropower development and other alterations of the hydrological network on downstream streamflow and drought risk were assessed for a mesoscale basin of steep topography in central Vietnam, the Vu Gia Thu Bon (VGTB) River basin. The Just Another Modelling System (JAMS)/J2000 was calibrated for the VGTB River basin to simulate reservoir inflow and the naturalized discharge time series for the downstream gauging stations. The HEC-ResSim reservoir operation model simulated reservoir outflow from eight major hydropower stations as well as the reconstructed streamflow for the main river branches Vu Gia and Thu Bon. Drought duration, severity, and frequency were analysed for different timescales for the naturalized and reconstructed streamflow by applying the daily varying threshold method. Efficiency statistics for both models show good results. A strong impact of reservoir operation on downstream discharge at the daily, monthly, seasonal, and annual scales was detected for four discharge stations relevant for downstream water allocation. We found a stronger hydrological drought risk for the Vu Gia river supplying water to the city of Da Nang and large irrigation systems especially in the dry season. We conclude that the calibrated model set-up provides a valuable tool to quantify the different origins of drought to support cross-sectorial water management and planning in a suitable way to be transferred to similar river basins.

Specific investigations related to salt rock behaviour

International Nuclear Information System (INIS)

Vons, L.H.

1985-01-01

In this paper results are given of work in various countries in rather unrelated areas of research. Nevertheless, since the studies have been undertaken to better understand salt behaviour, both from mechanical and chemical points of view, some connection between the studies can be found. In the French contribution the geological conditions have been investigated that might promote or prevent the formation of salt domes from layers in view of possible use of the latter type of formation. This was done theoretically by the finite element method, and a start was made with centrifuge tests. The density of a number of samples from salt and overburden from the Bresse basin was measured and it was shown that a favourable condition exists in this region for waste disposal. In the German contribution various subjects are touched upon, one being the effect of water on the mobility in the early stages of salt dome formation. Evidence was found for an anisotropy in salt. One Dutch contribution describes results of studies on the effect of small amounts of water on the rheology of salt. The results imply that flow laws obtained for salt at rapid strain rates and/or low confining pressure cannot be reliably extrapolated to predict the long term behaviour of wet or even very dry material under natural conditions. Preliminary results on the effect of water upon ion-mobility indicate a certain pseudo-absorptive capacity of salt e.g. for Sr

Late Pleistocene sedimentation: A case study of the central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Borole, D

-Sea Research 1, Vol 40, No 4, pp 761-775, 1993 0967-0637/93 $6 00 + 0 00 Printed m Great Britain © 1993 Pergamon Press Lid Late Pleistocene sedimentation: a case study of the central Indian Ocean Basin D. V. BOROLE* (Recetved 26 August 1988, in revised... 26 + 0 11 4 10 + 0.20 1 30 + 0 10 5 03 20-25 1 10 + 0.07 3 60 + 0.14 1 08 ___ 0 09 5 3 30-35 1 51 + 0.10 3.28 + 0 34 1.10 + 0.15 5 3 65-70 1.08 + 0 05 3 20 + 0.23 0 97 + 0.09 4 38 80-85 0 81 + 0 05 1 80 + 0.12 0 63 + 0 06 4 37 Conanued 766 D V...

Tectono-Thermal History Modeling and Reservoir Simulation Study of the Nenana Basin, Central Alaska: Implications for Regional Tectonics and Geologic Carbon Sequestration

Science.gov (United States)

Dixit, Nilesh C.

Central Interior Alaska is an active tectonic deformation zone highlighted by the complex interactions of active strike-slip fault systems with thrust faults and folds of the Alaska Range fold-and-thrust belt. This region includes the Nenana basin and the adjacent Tanana basin, both of which have significant Tertiary coal-bearing formations and are also promising areas (particularly the Nenana basin) with respect to hydrocarbon exploration and geologic carbon sequestration. I investigate the modern-day crustal architecture of the Nenana and Tanana basins using seismic reflection, aeromagnetic and gravity anomaly data and demonstrate that the basement of both basins shows strong crustal heterogeneity. The Nenana basin is a deep (up to 8 km), narrow transtensional pull-apart basin that is deforming along the left-lateral Minto Flats fault zone. The Tanana basin has a fundamentally different geometry and is a relatively shallow (up to 2 km) asymmetrical foreland basin with its southern, deeper side controlled by the northern foothills of the central Alaska Range. NE-trending strike-slip faults within the Tanana basin are interpreted as a zone of clockwise crustal block rotation. Seismic refection data, well data, fracture data and apatite fission track data further constrain the tectonic evolution and thermal history of the Nenana basin. The Nenana basin experienced four distinct tectonic phases since Late Paleocene time. The basin initiated as a narrow half-graben structure in Late Paleocene with accumulation of greater than 6000 feet of sediments. The basin was then uplifted, resulting in the removal of up to 5000 feet of Late Paleocene sediments in Eocene to Oligocene time. During Middle to Late Miocene time, left lateral strike-slip faulting was superimposed on the existing half-graben system. Transtensional deformation of the basin began in the Pliocene. At present, Miocene and older strata are exposed to temperatures > 60°C in the deeper parts of the Nenana

Cenozoic sedimentation and exhumation of the foreland basin system preserved in the Precordillera thrust belt (31-32°S), southern central Andes, Argentina

Science.gov (United States)

Levina, Mariya; Horton, Brian K.; Fuentes, Facundo; Stockli, Daniel F.

2014-09-01

Andean retroarc compression associated with subduction and shallowing of the oceanic Nazca plate resulted in thin-skinned thrusting that partitioned and uplifted Cenozoic foreland basin fill in the Precordillera of west-central Argentina. Evolution of the central segment of the Precordillera fold-thrust belt is informed by new analyses of clastic nonmarine deposits now preserved in three intermontane regions between major east directed thrust faults. We focus on uppermost Oligocene-Miocene basin fill in the axial to frontal Precordillera at 31-32°S along the Río San Juan (Albarracín and Pachaco sections) and the flank of one of the leading thrust structures (Talacasto section). The three successions record hinterland construction of the Frontal Cordillera, regional arc volcanism, and initial exhumation of Precordillera thrust sheets. Provenance changes recorded by detrital zircon U-Pb age populations suggest that initial shortening in the Frontal Cordillera coincided with an early Miocene shift from eolian to fluvial accumulation in the adjacent foreland basin. Upward coarsening of fluvial deposits and increased proportions of Paleozoic clasts reflect cratonward (eastward) advance of deformation into the Precordillera and resultant structural fragmentation of the foreland basin into isolated intermontane segments. Apatite (U-Th)/He thermochronometry of basin fill constrains to 12-9 Ma the most probable age of uplift-induced exhumation and cooling of Precordillera thrust sheets. This apparent pulse of exhumation is evident in each succession, suggestive of rapid, large-scale exhumation by synchronous thrusting above a single décollement linking major structures of the Precordillera.

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

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

The Use of {delta}{sup 37}CL to Explain Origin and Production of Salt from the Saline Spring 'Fonte da Pipa' in Rio Maior (Central Portugal)

Energy Technology Data Exchange (ETDEWEB)

Eggenkamp, H. G.M.; Marques, J. M. [Centro de Petrologia e Geoquimica, Instituto Superior Tecnico, Lisbon (Portugal); Graca, H. [Centro Hospitalar das Caldas da Rainha, Caldas da Rainha (Portugal)

2013-07-15

Salt extraction in Rio Maior (Central Portugal) is unique in the sense that salt is exploited from a very saline (134 g/L NaCl) terrestrial spring. This spring receives its salt through meteoric water circulation from nearby hills along a shallow salt diapir. This is shown using {delta}{sup 37}Cl, as the composition in dug wells between the mountains and the saline spring is comparable, while {delta}{sup 37}Cl in a well to the east is significantly different. Unlike seawater this spring contains nearly pure NaCl, giving us the opportunity to determine {delta}{sup 37}Cl values in a natural salt precipitating system beyond the point where (in seawater) potassium and magnesium chlorides start to precipitate. {delta}{sup 37}Cl values were determined from brines and by precipitating salt in salt pans with different evaporation stages. Fractionation of up to 1 per mille was found. To complement these natural data, evaporation/precipitation experiments are currently being conducted under controlled laboratory conditions. First results of these experiments indicate that during continued evaporation and precipitation {delta}{sup 37}Cl continues to decrease. (author)

New Interpretations of the Rayn Anticlines in the Arabian Basin Inferred from Gravity Modelling

Science.gov (United States)

AlMogren, S. M.; Mukhopadhyay, M.

2014-12-01

The Ryan Anticlines comprise of a regularly-spaced set of super-giant anticlines oriented NNW, developed due to E-W compression in the Arabian Basin. Most prominent of these being: the Ghawar Anticline, followed by the Summan, Khurais Anticlines and Qatar Arch. Gravity anomaly is largely characteristic for both Ryan Anticlines and its smaller size version the Jinadriah Anticline in the Riyadh Salt Basin. It displays a bipolar gravity field - a zone of gravity high running along the fold axis that is flanked by asymmetric gravity lows. Available structural models commonly infer structural uplift for the median gravity high but ignore the flanking lows. Here we interpret the bipolar gravity anomaly due primarily to such anticline structures, while, the flanking gravity lows are due to greater sediment thickness largely compacted and deformed over the basement depressions. Further complexities are created due to the salt layer and its migration at the lower horizons of sediment strata. Such diagnostic gravity anomaly pattern is taken here as an evidence for basement tectonics due to prevailing crustal dynamics in the Arabian Basin. Density inversion provides details on the subsurface density variation due to the folding and structural configuration for the sediment layers, including the salt layer, affected by basement deformation. This interpretation is largely supported by gravity forward and inversion models given in the present study what is partly constrained by the available seismic, MT and deep resistivity lines and surface geologic mapping. Most of the oil-gas fields in this part of the Arabian Basin are further known for salt diapirism. In this study the gravity interpretation help in identification of salt diapirism directly overlying the basement is firstly given here for Jinadriah Anticline; that is next extended to a regional geologic cross-section traversing the Ryan Anticlines to infer probable subsurface continuation of salt diapirs directly overlying

Salt tectonics in an experimental turbiditic tank

Science.gov (United States)

Sellier, Nicolas; Vendeville, Bruno

2010-05-01

We modelled the effect of the deposition of clastic sediments wedges along passive margin by combining two different experimental approaches. The first approach, which uses flume experiments in order to model turbiditic transport and deposition, had focused, so far mainly on the stratigraphic architecture and flow properties. But most experiments have not accounted for the impact of syndepositional deformation. The second approach is the classic tectonic modelling (sand-box experiments) is aimed essentially at understanding deformation, for example the deformation of a sediment wedge deposited onto a mobile salt layer. However, with this approach, the sediment transport processes are crudely modelled by adding each sediment layer uniformly, regardless of the potential influence of the sea-floor bathymetry on the depositional pattern. We designed a new tectono-stratigraphic modelling tank, which combines modelling of the turbiditic transport and deposition, and salt-related deformation driven by sediment loading. The set-up comprises a channel connected to a main water tank. A deformation box is placed at the mouth of the channel, on the base of the tank. The base of the box can be filled with various kinds of substrates either rigid (sand) or viscous (silicone polymer, simulating mobile salt layer having varying length and thickness). A mixture of fine-grained powder and water is maintained in suspension in a container, and then released and channelled toward the basin, generating an analogue of basin-floor fans or lobes. We investigated the effect of depositing several consecutive turbiditic lobes on the deformation of the salt body and its overburden. The dynamics of experimental turbidity currents lead to deposits whose thickness varied gradually laterally: the lobe is thick in the proximal region and thins progressively distally, thus creating a very gentle regional surface slope. As the fan grows by episodic deposition of successive turbiditic lobes, the model

Petroleum systems and geologic assessment of undiscovered oil and gas, Cotton Valley group and Travis Peak-Hosston formations, East Texas basin and Louisiana-Mississippi salt basins provinces of the northern Gulf Coast region. Chapters 1-7.

Science.gov (United States)

,

2006-01-01

The purpose of the U.S. Geological Survey's (USGS) National Oil and Gas Assessment is to develop geologically based hypotheses regarding the potential for additions to oil and gas reserves in priority areas of the United States. The USGS recently completed an assessment of undiscovered oil and gas potential of the Cotton Valley Group and Travis Peak and Hosston Formations in the East Texas Basin and Louisiana-Mississippi Salt Basins Provinces in the Gulf Coast Region (USGS Provinces 5048 and 5049). The Cotton Valley Group and Travis Peak and Hosston Formations are important because of their potential for natural gas resources. This assessment is based on geologic principles and uses the total petroleum system concept. The geologic elements of a total petroleum system include hydrocarbon source rocks (source rock maturation, hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy and petrophysical properties), and hydrocarbon traps (trap formation and timing). The USGS used this geologic framework to define one total petroleum system and eight assessment units. Seven assessment units were quantitatively assessed for undiscovered oil and gas resources.

Deformation and transport processes in salt rocks : An experimental study exploring effects of pressure and stress relaxation

NARCIS (Netherlands)

Muhammad, Nawaz

2015-01-01

The presence of evaporitic formations in sedimentary basins, often dominated by the salt mineral halite, is of great influence on the structural style developed during tectonic events. On a somewhat smaller scale, salt rocks often host a variety of deep solution mined caverns, which are increasingly

Madbi Amran/Qishn total petroleum system of the Ma'Rib-Al Jawf/Shabwah, and Masila-Jeza basins, Yemen

Science.gov (United States)

Ahlbrandt, Thomas S.

2002-01-01

Since the first discovery of petroleum in Yemen in 1984, several recent advances have been made in the understanding of that countrys geologic history and petroleum systems. The total petroleum resource endowment for the combined petroleum provinces within Yemen, as estimated in the recent U.S. Geological Survey world assessment, ranks 51st in the world, exclusive of the United States, at 9.8 BBOE, which includes cumulative production and remaining reserves, as well as a mean estimate of undiscovered resources. Such undiscovered petroleum resources are about 2.7 billion barrels of oil, 17 trillion cubic feet (2.8 billion barrels of oil equivalent) of natural gas and 1 billion barrels of natural gas liquids. A single total petroleum system, the Jurassic Madbi Amran/Qishn, dominates petroleum generation and production; it was formed in response to a Late Jurassic rifting event related to the separation of the Arabian Peninsula from the Gondwana supercontinent. This rifting resulted in the development of two petroleum-bearing sedimentary basins: (1) the western MaRibAl Jawf / Shabwah basin, and (2) the eastern Masila-Jeza basin. In both basins, petroleum source rocks of the Jurassic (Kimmeridgian) Madbi Formation generated hydrocarbons during Late Cretaceous time that migrated, mostly vertically, into Jurassic and Cretaceous reservoirs. In the western MaRibAl Jawf / Shabwah basin, the petroleum system is largely confined to syn-rift deposits, with reservoirs ranging from deep-water turbidites to continental clastics buried beneath a thick Upper Jurassic (Tithonian) salt. The salt initially deformed in Early Cretaceous time, and continued halokinesis resulted in salt diapirism and associated salt withdrawal during extension. The eastern Masila-Jeza basin contained similar early syn-rift deposits but received less clastic sediment during the Jurassic; however, no salt formed because the basin remained open to ocean circulation in the Late Jurassic. Thus, Madbi Formation

Angola: source rock control for Lower Congo Coastal and Kwanza Basin petroleum systems

Energy Technology Data Exchange (ETDEWEB)

Burwood, R. [Fina Exploration Ltd, Epsom (United Kingdom)

1999-07-01

The purpose of this paper is to provide an overview of petroleum occurrence and provenance for the 1000 km West African Atlantic Margin from Cabinda to mid-Angola. Over this margin the Lower Congo Coastal and Kwanza provinces cumulatively account for reserves of c. 6 gigabarrels oil recoverable (GBOR). These are dominantly reservoired in Pinda carbonate traps of the former basin. However, with production from a range of aggradational wedge, carbonate platform and pre-salt reservoirs, a diversity in oil character presupposes complex hydrocarbon habitats charged by multiple sourcing. Each of these two major Atlantic margin salt basins constitutes a different, source rock driven, hydrocarbon habitat. As classic passive margin pull-apart basins, Early Cretaceous initiated rift events (Pre-rift, Syn-rift I, II, etc.) evolved into the drift phase opening of the southern Atlantic. A striking feature of this progression was widespread evaporite deposition of the Aptian Loeme salt. This separates two distinct sedimentary and tectonic domains of the Pre- and Post-Salt. The core Lower Congo Coastal habitat is dominated by the Pre-Salt Bucomazi Formation sourced 'poly' petroleum system. These lacustrine, often super-rich, sediments reveal considerable organofacies variation between their basin fill (Syn-rift I) and sheet drape (Syn-rift II) development, accounting for the compositional diversity in their progenic petroleums. Of crucial impact is a cognate diversity in their kerogen kinetic behaviour. This controls the conditions and timing of generation and realization of charge potential. With the Lower Congo Coastal habitat extending southwards towards the Ambriz Spur, the Bucomazi facies proper appears restricted to the northern and deeper proto-lake trend. Over the more weakly subsident margins such troughs host inferior sheet drape potential. Elswhere, Upper Cretaceous-Palaeogene marine clastic Iabe Formation sourced petroleum systems are hydrocarbon productive

Laboratory testing of rock and salt samples for determination of specific gravity and total porosity of the Zeeck No. 1 well (PD-7), Palo Duro Basin, Texas: unanalyzed data

International Nuclear Information System (INIS)

1984-07-01

This report contains the specific gravity and total porosity determinations for rock and salt samples from Zeeck No. 1 Well of the Permian Basin. The laboratory test samples were measured for water content, apparent specific gravity, specific gravity of solids, total porosity and effective porosity. Specimen descriptions including specimen number, formation/group, and lithologic description as well as typical data sheets are included in the appendices. These data are preliminary. They have been neither analyzed nor evaluated

Nature, source and composition of volcanic ash in sediments from a fracture zone trace of Rodriguez Triple Junction in the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Mascarenhas-Pereira, M.B.L.; Nath, B.N.; Borole, D.V.; Gupta, S.M.

Volcanic glasses associated with pumice, micro nodules and palagonite like lithic fragments were recovered from a volcanic terrain in a fracture zone defined as Rodriguez Triple Junction trace in the Central Indian Basin. Morphologically, the tephra...

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

Chlorine isotopic geochemistry of salt lakes in the Qaidam Basin, China

Digital Repository Service at National Institute of Oceanography (India)

Liu, W.G.; Xiao, Y.K.; Wang, Q.Z.; Qi, H.P.; Wang, Y.H.; Zhou, Y.M.; Shirodkar, P.V.

*Cl+ ion. Int. J. Mass Spectrom. Ion Process., 116: crysatallization of saline minerals in salt lake. J. Salt Lake 183-192. Sci., 2: 35-40 (in Chinese). Xiao, Y.K., Sun, D.P., Wang, Y.H., Qi, H.P. and Jin, L., 1992. Boron isotopic compositions of brine..., sediments, and source water in Da Qaidam Lake, Qinghai, China. Geochim. Cos- mochim. Acta, 56: 1.561-1568. Xiao, Y.K., Jin, L., Liu. W.G., Qi, H.P., Wang, W.H. and Sun, D.P., 1994a. The isotopic compositions of chlorine in Da Qaidam Lake. Chin. Sci...

New insights into the structure of Om Ali-Thelepte basin, central Tunisia, inferred from gravity data: Hydrogeological implications

Science.gov (United States)

Harchi, Mongi; Gabtni, Hakim; El Mejri, Hatem; Dassi, Lassaad; Mammou, Abdallah Ben

2016-08-01

This work presents new results from gravity data analyses and interpretation within the Om Ali-Thelepte (OAT) basin, central Tunisia. It focuses on the hydrogeological implication, using several qualitative and quantitative techniques such as horizontal gradient, upward continuation and Euler deconvolution on boreholes log data, seismic reflection data and electrical conductivity measurements. The structures highlighted using the filtering techniques suggest that the Miocene aquifer of OAT basin is cut by four major fault systems that trend E-W, NE-SW, NW-SE and NNE-SSW. In addition, a NW-SE gravity model established shows the geometry of the Miocene sandstone reservoir and the Upper Cretaceous limestone rocks. Moreover, the superimposition of the electrical conductivity and the structural maps indicates that the low conductivity values of sampled water from boreholes are located around main faults.

A new report on the occurrence of zeolitites in the abyssal depths of the Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Iyer, S.D.; Sudhakar, M.

of Oceanography, Dona Paula, Goa 403 004, India (Received August 13, 1992; revised version accepted November 18, 1992) ABSTRACT Forty-two indurated slabs of zeolites collected from the abyssal depths of the Central Indian Basin have been studied. The slabs... Depth Sampler Topography/ No. (dimensions in cm) (°S) (°E) (m) deployed sediment type 1 SS17/877 (A) Ferromanganese oxides with patches of 13.032 75.743 4275 Dredge Seamount flank/ orangish-yellow material, 25 × 21...

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

A reassessment of the Archean-Mesoproterozoic tectonic development of the southeastern Chhattisgarh Basin, Central India through detailed aeromagnetic analysis

Science.gov (United States)

Sridhar, M.; Ramesh Babu, V.; Markandeyulu, A.; Raju, B. V. S. N.; Chaturvedi, A. K.; Roy, M. K.

2017-08-01

We constrained the geological framework over polydeformed Paleoproterozoic Sonakhan Greenstone Belt and addressed the tectonic evolution of Singhora basin in the fringes of Bastar Craton, central India by utilizing aeromagnetic data interpretation, 2.5D forward modelling and 3D magnetic susceptibility inversions. The Sonakhan Greenstone Belt exposes volcano-sedimentary sequences of the Sonakhan Group within NNW-SSE to NW-SE trending linear belts surrounded by granite gneisses, which are unconformably overlain by sedimentary rocks of Chhattisgarh Basin. The orientations of aeromagnetic anomalies are coincident with geological trends and appear to correlate with lithology and geologic structure. Regional magnetic anomalies and lineaments reveal both NNW-SSE and NE-SW trends. Prominent E-W trending linear, high amplitude magnetic anomalies are interpreted as the Trans-Chhattisgarh Aeromagnetic Lineament (TCAL). NW-SE trending aeromagnetic signatures related to Sonakhan Greenstone Belt extends below the Singhora sedimentary rocks and forms the basement in the west. The analysis suggests that TCAL is a block fault with northern block down-thrown and affected the basement rocks comprising the Sonakhan Greenstone Belt and Samblapur Granitoids. The episode of faulting represented by the TCAL is pre-Singhora sedimentation and played a vital role in basin evolution. The basement configuration image generated by estimates of depth to magnetic basement suggests a complex pattern of NNE-SSW to NE-SW trending depressions separated by a linear N-S trending basement ridge. It is inferred from the 3D magnetic susceptibility inversion that the thickness of sediments is more towards the eastern basin margin and the N-S ridge is a manifestation of post sedimentary faulting. Results of 2.5D modelling of a WNW-ESE profile across the Singhora Basin combined with results from 3D inversion suggest suggests the basin subsidence was controlled by NE-SW trending regional faults in an active

Site characterization plan: Gulf Coast salt domes

International Nuclear Information System (INIS)

1983-12-01

The National Waste Terminal Storage (NWTS) program of the US Department of Energy (DOE) is responsible for developing technology and providing facilities for safe, environmentally acceptable, permanent disposal of high-level nuclear waste. The Office of Nuclear Waste Isolation has been intensively investigating Gulf Coast Salt Dome Basin salt domes and bedded salt in Texas and Utah since 1978. In the Gulf Coast, the application of screening criteria in the region phase led to selection of eight domes for further study in the location phase. Further screening in the area phase identified four domes for more intensive study in the location phase: Oakwood Dome, Texas; Vacherie Dome, Louisiana; and Richton Dome and Cypress Creek Dome, Mississippi. For each dome, this Site Characterization Plan identifies specific hydrologic, geologic, tectonic, geochemical, and environmental key issues that are related to the DOE/NWTS screening criteria or affect the feasibility of constructing an exploratory shaft. The Site Characterization Plan outlines studies need to: (1) resolve issues sufficiently to allow one or more salt domes to be selected and compared to bedded salt sites in order to determine a prime salt site for an exploratory shaft; (2) conduct issue-related studies to provide a higher level of confidence that the preferred salt dome site is viable for construction of an exploratory shaft; and (3) provide a vehicle for state input to issues. Extensive references, 7 figures, 20 tables

Hydrogeology and hydrogeochemistry at a site of strategic importance: the Pareja Limno-reservoir drainage basin (Guadalajara, central Spain)

Science.gov (United States)

Molina-Navarro, Eugenio; Sastre-Merlín, Antonio; Vicente, Rosa; Martínez-Pérez, Silvia

2014-08-01

A small calcareous basin in central Spain was studied to establish the role of groundwater in the Pareja Limno-reservoir. Limno-reservoirs aim to preserve a constant water level in the riverine zone of large reservoirs to mitigate the impacts arising from their construction. Groundwater flow contribution (mean 60 %) was derived by recharge estimation. In situ measurements (spring discharge, electrical conductivity and sulfate) were undertaken and spring discharge was compared with a drought index. Twenty-eight springs were monitored and three hydrogeological units (HGUs) were defined: a carbonate plateau (HGU1), the underlying aquitard (HGU2), and the gypsum-enriched HGU3. HGU1 is the main aquifer and may play a role in the preservation of the limno-reservoir water level. Hydrogeochemical sampling was conducted and the code PHREEQC used to describe the main geochemical processes. Weathering and dissolution of calcite and gypsum seem to control the hydrogeochemical processes in the basin. Water progresses from Ca2+-HCO3 - in the upper basin to Ca2+-SO4 2- in the lower basin, where HGU3 outcrops. A clear temporal pattern was observed in the limno-reservoir, with salinity decreasing in winter and increasing in summer. This variation was wider at the river outlet, but the mixing of the river discharge with limno-reservoir water buffered it.

Implementation of MAR within the Rio Grande Basin of Central New Mexico, USA

Science.gov (United States)

Marley, Robert; Blandford, T. Neil; Ewing, Amy; Webb, Larry; Yuhas, Katherine

2014-05-01

The U.S. Bureau of Reclamation has identified the Rio Grande basin within Central New Mexico as one of several regions where water supplies are over-allocated and future conflicts over the inadequate resource are highly likely. Local water providers have consistently identified managed aquifer recharge (MAR) as an important tool to provide conjunctive management of surface-water, groundwater, and reclaimed water sources in order to extend the useful life of existing water sources. However, MAR projects have been slow to take root partly due to rigorous demonstration requirements, groundwater quality protection concerns, and ongoing water right uncertainties. At first glance the several thousand meters of unconsolidated basin-fill sediments hosting the regional aquifer appear to provide an ideal environment for the subsurface storage of surplus water. However, the basin has a complex structural and depositional history that impacts the siting and overall effectiveness of MAR systems. Several recharge projects are now in various stages of implementation and are overcoming site specific challenges including source water and ambient groundwater compatibility, low-permeability sediments and compartmentalization of the aquifer by extensive faulting, well clogging, and overall water quality management. This presentation will highlight ongoing efforts of these water providers to develop full-scale recharge facilities. The performance of natural in-channel infiltration, engineered infiltration galleries, and direct injection systems designed to introduce from 500 to 5,000 mega-liters per annum to target intervals present from 150 to 600 meters below ground surface will be described. Source waters for recharge operations include inter-basin transferred surface water and highly treated reclaimed water sources requiring from minor to extensive treatment pre-recharge and post-recovery. Operational complexities have raised concerns related to long-term operation and maintenance

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

Origin and Development of El Bajío Basin in the Central Sector of Trans-Mexican Volcanic Belt

Science.gov (United States)

Botero, P. A.; Alaniz Álvarez, S. A.; Nieto Samaniego, Á. F.; Lopez-Martinez, M.; Levresse, G.; Xu, S.; Ortega Obregón, C.

2015-12-01

Volcanism of the Trans-Mexican Volcanic Belt has been placed on pre-existing tectonic basins; one of them is El Bajío Basin. We present the origin and evolution of this basin through the study of its deformation events occurring mainly on the El Bajío fault, at the boundary between the Trans-Mexican Volcanic Belt and the Mesa Central. Detailed stratigraphy, and structural analysis suggest 4 deformation events in the northwest of the Sierra de Guanajuato. The first event (D1) with E-W shortening is characterized by the development of axial plane foliation (S1) with N-S direction, this event occurred between the Tithonian and Aptian age. In the second event (D2), occurred between the Albian and the early Eocene, foliations NW-SE (S2) were generated with a NE-SW shortening trend dated between the Albian and early Eocene, this deformation is related to the Laramide Orogeny. The Granito Comanja was emplaced during the third event (D3) and generated foliation (S3) in sediments of the complejo vulcanosedimentario Sierra de Guanajuato that circumscribes the Granito Comanja in response to its intrusion. After its emplacement, NW-SE normal faults were generated along the S-SE contact of the Granito Comanja, at that time El Bajío fault began. The fourth event (D4) has three phases that affected the sedimentary and volcanic Cenozoic rocks. D4F1 is marked by continental conglomerates deposition with variable thickness along of the main trace of the El Bajío fault. D4F2 affected the Oligocene volcanic rocks showing an important fault activity at that time, as evidenced the tilting above 45o in the Oligocene rocks, temporarily coincides with the triaxial extension to the Mesa Central. The direction of elongation of D4F3 is ESE-WNW, El Bajío fault had little movement. Since the Miocene the deformation was concentrated along the southern central sector of the Trans-mexican Volcanic Belt and there were few deformation in the Mesa central. During the three phases of deformation

Mesozoic and Cenozoic tectonics of the eastern and central Alaska Range: Progressive basin development and deformation in a suture zone

Energy Technology Data Exchange (ETDEWEB)

Ridgway, K.D.; Trop, J.M.; Nokleberg, W.J.; Davidson, C.M.; Eastham, K.R. [Purdue University, W. Lafayette, IN (United States). Dept. of Earth & Atmospheric Science

2002-07-01

Analysis of late Mesozoic and Cenozoic sedimentary basins, metamorphic rocks, and major faults in the eastern and central Alaska Range documents the progressive development of a suture zone that formed as a result of collision of an island-arc assemblage (the Wrangellia composite terrane) with the former North American continental margin. New basin-analysis, structural, and geochronologic data indicate the following stages in the development of the suture zone: (1) Deposition of 3-5 km of Upper Jurassic-Upper Cretaceous marine strata (the Kahiltna assemblage) recorded the initial collision of the island-arc assemblage with the continental margin. (2) Metamorphism of submarine-fan deposits of the Kahiltna basin, located near the leading edge of the island-arc assemblage, occurred at ca. 74 Ma, as determined from a new U-Pb zircon age for a synkinematic sill. (3) Shortening and exhumation of the suture zone peaked from 65 to 60 Ma on the basis of metamorphic and geochronologic data. (4) From 60 to 54 Ma, about 3 km of volcanic strata were deposited over deformed sedimentary strata of the Cantwell basin, and several granitic plutons (the McKinley sequence) were emplaced along the suture zone. (5) Following igneous activity, strike-slip displacement occurred from ca. 54 to 24 Ma along the Denali fault system, which had developed in the existing suture zone. (6) Regional transpressive shortening characterized the suture zone from ca. 24 Ma to the present. Regional subsidence resulted in Miocene coal seams up to 20 m thick and well-developed lacustrine deposits. Overlying the Miocene deposits are about 1.2 km of Pliocene and Holocene conglomeratic deposits. These mapping relationships provide evidence that regional shortening continues to the present in the eastern and central Alaska Range.

Salts and Co-crystals of Theobromine and their phase ...

Indian Academy of Sciences (India)

Co-crystal; dissolution; phase transformation; salts; solubility; stability; synthon. ... Salts of theobromine with hydrochloric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid and -toluenesulfonic acid were prepared using ... C. R. Rao Road, Gachibowli, Central University P.O., Hyderabad 500 046, India ...

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

CZO perspective in Central Africa : The Lopé watershed, Lopé National Park, Ogooué River basin, Gabon.

Science.gov (United States)

Braun, J. J.; Jeffery, K.; Koumba Pambo, A. F.; Paiz, M. C.; Richter, D., Jr.; John, P.; Jerome, G.

2015-12-01

Critical Zone Observatories (CZO) in equatorial regions are seldom (see e. g. http://www.czen.org/, USA and http://rnbv.ipgp.fr/, France). The equatorial zone of Central Africa is almost free of them with the exception of the CZO of the Upper Nyong river basin (organic-rich river on the lateritic plateau of South Cameroon; SO BVET, http://bvet.omp.obs-mip.fr/). On both sides of the Equator line, the Ogooué River Basin (215,000 km2) stretches on about 80% of the total area of Gabon and drains various geological and morpho-pedological contexts and feeds the sedimentation areas of the Central African passive margin (Guillochaux et al., 2014). The Upper Ogooué (up to Lambaréné) drains the stepped planation surface of the Congo craton while the Lower Ogooué drains Mesozoic and Cenozoic sedimentary terrains. The climate is equatorial (Pmean = 2500 mm/yr; Tmean = 26 °; %humidity > 80%). Continuous hydro-climatic chronicles exist for the period 1953-1974 (managed by ORSTOM, now IRD). The runoff at Lambaréné (92% of the basin area) is very high (714 mm/yr). With a rural density of 1 inhabitant/km2, it is one of the last largely pristine tropical forested ecosystems on the Planet. In addition, the basin will be, in the coming decades, the theatre of important anthropogenic changes (dams, agriculture, mining, urbanisation, …). However, a conservation plan with an ambitious sustainable development policy is set up. This plan articulates the environmental issues related to the emergence of the country. Because of these characteristics, the basin offers ideal conditions for studying the changes in equatorial region of hydro-climate, weathering/erosion regimes and regolith production based on morpho-pedological contexts and associated physical, chemical and biological processes. It is thus germane to launch an integrated CZO initiative at both regional scale and local scale. At the regional scale, we plan to reactivate some of the hydro-climatic stations located on the

Mineral chemistry, bulk composition and source of the ferromanganese nodules nuclei from the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Banerjee, R.; Miura, H.

and Planetary Science Letters 95:395—402 Kamesh Raju KA, Ramprasad T, Kodagali VN, and Nair RR (1993) Multibeam bathymetric, gravity and magnetic studies over 79¡E fracture zone, Central Indian Basin. Journal of Geophysical Research (B) 98: 9605—9618 Kikuchi... ( ) Geological Oceanography Division, National Institute of Oceanography, Dona Paula, Goa 403 004, India Hiroyuki Miura Department of Earth and Planetary Science, Graduate School of Science, Hokkaido University, 060 Sapporo, Japan Geo-Marine Letters (1998) 18: 66...

Geophysical Measurements in the Beaver Basin, West-Central Utah; Part 1--Slingram, Magnetic, and Self-Potential Profiles

OpenAIRE

Flanigan, Vincent J.; Campbell, David L.; U.S. Geological Survey

1981-01-01

This report consists of figures showing profile locations (fig. 1, table 1) in the Beaver Basin, west-central Utah, and ground geophysical data collected in September 1980 along these traverses (figs. 2-11). These data consist of slingram electromagnetic (real and imaginary components at 222, 444, 888, 1777, and 3555 Hz), ground magnetic and self-potential measurements collected at 200-foot (61-m) intervals along about 8.8 miles (14.2 km) of survey line. Table 2 lists equipment used. The r...

Geology and hydrocarbon potential of the Dead Sea Rift Basins of Israel and Jordan

Science.gov (United States)

Coleman, James; ten Brink, Uri S.

2016-01-01

Following its middle Miocene inception, numerous basins of varying lengths and depths developed along the Dead Sea fault zone, a large continental transform plate boundary. The modern day left-lateral fault zone has an accumulated left-lateral offset of 105 to 110 km (65 to 68 mi). The deepest basin along the fault zone, the Lake Lisan or Dead Sea basin, reaches depths of 7.5 to 8.5 km (24,500 ft to 28,000 ft), and shows evidence of hydrocarbons. The basins are compartmentalized by normal faulting associated with rapid basin subsidence and, where present, domal uplift accompanying synrift salt withdrawal.

Compilation of data for thermomechanical analyses of four potential salt repositories

International Nuclear Information System (INIS)

Tammemagi, H.Y.; Loken, M.C.; Osnes, J.D.; Wagner, R.A.

1986-01-01

This report includes a collection and summarization of the data which are necessary to perform thermomechanical analyses of four potential salt repository sites: Paradox Basin, Utah; Permian Basin, Texas; Richton Dome, Mississippi; and Vacherie Dome, Louisiana. Thermal, mechanical, and hydrogeological material properties are presented so that the numerical analyses can be subdivided into three geometric regions: canister, disposal room, and repository site. Data are presented for the salt formations, the surrounding geological units, and for human-made materials placed in the repository such as the nuclear waste and its protective steel liner. Wherever possible, site-specific data are used which have been determined from laboratory testing of drill core or from interpretation of geophysical logs. Although much effort has been made to obtain the most appropriate data, there are deficiencies because some of the required site-specific data are either not available or are inconsistent with anticipated values

Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

Science.gov (United States)

Tumbusch, Mary L.; Plume, Russell W.

2006-01-01

The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond

Temporal variations of water and sediment fluxes in the Cointzio river basin, central Mexico

Science.gov (United States)

Duvert, C.; Gratiot, N.; Navratil, O.; Esteves, M.; Prat, C.; Nord, G.

2009-04-01

The STREAMS program (Sediment TRansport and Erosion Across MountainS) was launched in 2006 to study suspended sediment dynamics in mountainous areas. Two watersheds were selected as part of the program: the Bléone river basin in the French Alps, and the Cointzio river basin (636 km2), located in the mountainous region of Michoacán, in central Mexico. The volcanic soils of the Cointzio catchment undergo important erosion processes, especially during flashflood events. Thus, a high-frequency monitoring of sediment transport is highly required. The poster presents the high-frequency database obtained from the 2008 hydrological season at the Santiago Undameo gauged station, located at the basin's outlet. Suspended Sediment Concentration (SSC) was estimated every 10 minutes by calibrating turbidity measurements with bottle sampling acquired on a double-daily basis. Water discharge time-series was approximated with continuous water-level measurements (5 minutes time-step), and a stage-discharge rating curve. Our investigation highlights the influence of sampling frequency on annual water and sediment fluxes estimate. A daily or even a weekly water-level measurement provides an unexpectedly reliable assessment of the seasonal water fluxes, with an under-estimation of about 5 % of the total flux. Concerning sediment fluxes, a high-frequency SSC survey appears to be necessary. Acquiring SSC data even twice a day leads to a significant (over 30 %) under-estimation of the seasonal sediment load. These distinct behaviors can be attributed to the fact that sediment transport almost exclusively occurs during brief night flood events, whereas exfiltration on the watershed always provides a base flow during the daily water-level measurements.

Origin of salt giants in abyssal serpentinite systems

Science.gov (United States)

Scribano, Vittorio; Carbone, Serafina; Manuella, Fabio C.; Hovland, Martin; Rueslåtten, Håkon; Johnsen, Hans-K.

2017-10-01

Worldwide marine salt deposits ranging over the entire geological record are generally considered climate-related evaporites, derived from the precipitation of salts (mainly chlorides and sulfates) from saturated solutions driven by solar evaporation of seawater. This explanation may be realistic for a salt thickness ≤100 m, being therefore inadequate for thicker (>1 km) deposits. Moreover, sub-seafloor salt deposits in deep marine basins are difficult to reconcile with a surface evaporation model. Marine geology reports on abyssal serpentinite systems provide an alternative explanation for some salt deposits. Seawater-driven serpentinization consumes water and increases the salinity of the associated aqueous brines. Brines can be trapped in fractures and cavities in serpentinites and the surrounding `country' rocks. Successive thermal dehydration of buried serpentinites can mobilize and accumulate the brines, forming highly saline hydrothermal solutions. These can migrate upwards and erupt onto the seafloor as saline geysers, which may form salt-saturated water pools, as are currently observed in numerous deeps in the Red Sea and elsewhere. The drainage of deep-seated saline brines to seafloor may be a long-lasting, effective process, mainly occurring in areas characterized by strong tectonic stresses and/or igneous intrusions. Alternatively, brines could be slowly expelled from fractured serpentinites by buoyancy gradients and, hence, separated salts/brines could intrude vertically into surrounding rocks, forming salt diapirs. Serpentinization is an ubiquitous, exothermic, long-lasting process which can modify large volumes of oceanic lithosphere over geological times. Therefore, buried salt deposits in many areas of the world can be reasonably related to serpentinites.

Organic petrology of the Aptian-age section in the downdip Mississippi Interior Salt Basin, Mississippi, USA: Observations and preliminary implications for thermal maturation history

Science.gov (United States)

Valentine, Brett J.; Hackley, Paul C.; Enomoto, Catherine B.; Bove, Alana M.; Dulong, Frank T.; Lohr, Celeste D.; Scott, Krystina R.

2014-01-01

This study identifies a thermal maturity anomaly within the downdip Mississippi Interior Salt Basin (MISB) of southern Mississippi, USA, through examination of bitumen reflectance data from Aptian-age strata (Sligo Formation, Pine Island Shale, James Limestone, and Rodessa Formation). U.S. Geological Survey (USGS) reconnaissance investigations conducted in 2011–2012 examined Aptian-age thermal maturity trends across the onshore northern Gulf of Mexico region and indicated that the section in the downdip MISB is approaching the wet gas/condensate window (Ro~1.2%). A focused study in 2012–2013 used 6 whole core, one sidewall core, and 49 high-graded cutting samples (depth range of 13,000–16,500 ft [3962.4–5029.2 m] below surface) collected from 15 downdip MISB wells for mineralogy, fluid inclusion, organic geochemistry, and organic petrographic analysis. Based on native solid bitumen reflectance (Ro generally > 0.8%; interpreted to be post-oil indigenous bitumens matured in situ), Ro values increase regionally across the MISB from the southeast to the northwest. Thermal maturity in the eastern half of the basin (Ro range 1.0 to 1.25%) appears to be related to present-day burial depth and shows a gradual increase with respect to depth. To the west, thermal maturity continues to increase even as the Aptian section shallows structurally on the Adams County High (Ro range 1.4 to > 1.8%). After evaluating the possible thermal agents responsible for increasing maturity at shallower depths (i.e., igneous activity, proximity to salt, variations in regional heat flux, and uplift), we tentatively propose that either greater paleoheat flow or deeper burial coupled with uplift in the western part of the MISB could be responsible for the thermal maturity anomaly. Further research and additional data are needed to determine the cause(s) of the thermal anomaly.

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

Raft tectonics in northern Campos Basin; Tectonica de jangada (raft tectonics) na area norte da Bacia de Campos

Energy Technology Data Exchange (ETDEWEB)

Castro, Marilia R. de [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil)]|[PETROBRAS, Macae, RJ (Brazil). Unidade de Negocio da Bacia de Campos; Fugita, Adhemar M. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Programa de Recursos Humanos da ANP

2004-07-01

In the northern area of Campos Basin salt gliding/spreading processes promoted the break-up and transport of Cretaceous and Tertiary rocks overlying the evaporites. This process is known as raft tectonics, and it represents the most extreme form of thin-skinned extension above the salt decollement surface. Three distinct geotectonic domains were recognized that formed in response to the raft tectonics. The first one, confined to the shallower shelf portion of the basin, is characterized by minor extension (pre-raft domain), probably because of small salt thickness and low gradient. In the second domain (or disorganized rafts domain), located in distal platformal and slope areas, seismic sections show the occurrence of blocks or rafts with angular shapes, sometimes imbricated and frequently discontinuous. In the third domain, or domain of organized rafts, located in bacinal region, seismic sections show a more continuous raft pattern, often folded because of salt compression in the distal portions of the basin. The main purposes of this work is to characterize these three tectonic domains distinguished by raft tectonics, as well as their importance in hydrocarbon accumulations in calcarenites. (author)

Characterization of habitat and biological communities at fixed sites in the Great Salt Lake basins, Utah, Idaho, and Wyoming, water years 1999-2001

Science.gov (United States)

Albano, Christine M.; Giddings, Elise M.P.

2007-01-01

Habitat and biological communities were sampled at 10 sites in the Great Salt Lake Basins as part of the U.S. Geological Survey National Water-Quality Assessment program to assess the occurrence and distribution of biological organisms in relation to environmental conditions. Sites were distributed among the Bear River, Weber River, and Utah Lake/Jordan River basins and were selected to represent stream conditions in different land-use settings that are prominent within the basins, including agriculture, rangeland, urban, and forested.High-gradient streams had more diverse habitat conditions with larger substrates and more dynamic flow characteristics and were typically lower in discharge than low-gradient streams, which had a higher degree of siltation and lacked variability in geomorphic channel characteristics, which may account for differences in habitat. Habitat scores were higher at high-gradient sites with high percentages of forested land use within their basins. Sources and causes of stream habitat impairment included effects from channel modifications, siltation, and riparian land use. Effects of hydrologic modifications were evident at many sites.Algal sites where colder temperatures, less nutrient enrichment, and forest and rangeland uses dominated the basins contained communities that were more sensitive to organic pollution, siltation, dissolved oxygen, and salinity than sites that were warmer, had higher degrees of nutrient enrichment, and were affected by agriculture and urban land uses. Sites that had high inputs of solar radiation and generally were associated with agricultural land use supported the greatest number of algal species.Invertebrate samples collected from sites where riffles were the richest-targeted habitat differed in species composition and pollution tolerance from those collected at sites that did not have riffle habitat (nonriffle sites), where samples were collected in depositional areas, woody snags, or macrophyte beds

Lateral mobility of minibasins during shortening: Insights from the SE Precaspian Basin, Kazakhstan

Science.gov (United States)

Duffy, Oliver B.; Fernandez, Naiara; Hudec, Michael R.; Jackson, Martin P. A.; Burg, George; Dooley, Tim P.; Jackson, Christopher A.-L.

2017-04-01

Minibasin provinces are widespread and can be found in all types of salt tectonic settings, many of which are prone to shortening. Previous studies of how minibasin provinces shorten assume that the salt between the minibasins is homogeneous and that the base of salt is flat or of low relief, such that minibasins are free to move laterally. Here we investigate how minibasin provinces respond to shortening when the lateral mobility of the minibasins is restricted by intra-salt sediment bodies, in order to gain a greater understanding of the controls on the structural styles and modes of tectono-stratigraphic evolution exhibited in minibasin provinces. We examine a borehole-constrained, 3D seismic reflection dataset from the SE Precaspian Basin (onshore western Kazakhstan). The study area is characterised by large, supra-salt minibasins and an array of smaller intra-salt sediment packages distributed between these larger minibasins. We first outline the evidence of episodic shortening between the Late Triassic and present, after the onset of supra-salt minibasin subsidence. Next, we document spatial variations in shortening style, showing how these relate to the concentration of intra-salt sediment packages. Finally, we develop synoptic models showing how intra-salt sediment packages influence both the lateral mobility of minibasins during shortening and the resultant structural style, and we compare and contrast our findings with existing models and other natural examples of shortened minibasin provinces. We conclude that minibasin provinces may have different degrees of lateral mobility depending on the presence, or absence, of intrasalt barriers, and that these variations provide a first-order control on basin-shortening style and tectono-stratigraphic evolution.

Thick sedimentary sequence around Bahraich in the northern part of the central Ganga foreland basin

Science.gov (United States)

Manglik, A.; Adilakshmi, L.; Suresh, M.; Thiagarajan, S.

2015-06-01

We present the results of a magnetotelluric study along a 285 km long profile between Hamirpur and Rupadia (Nepal border) across the central Ganga basin. The electrical resistivity image obtained by combining 1-D Occam inversion models for 39 sites reveals a significant contrast in the subsurface structure from south to north along the profile. At the southern end, the Bundelkhand massif is delineated as a high resistivity block buried beneath 250-300 m thick sediments. The thickness of sediments gradually increases to about 500-600 m at Kanpur, and to about 1.2 km at Lucknow. Here, the basement depth increases to more than 2.5 km within a profile distance of 20 km, which could be attributed to the Lucknow fault. The underlying rocks also have moderate resistivity and possibly represent the Vindhyans. The sedimentary sequence at the northern end of the profile around Bahraich is more than 9 km thick. Integrating the resistivity image with a published seismic velocity structure from the region and the lithology from the 3927 m deep Matera-I well reveals that the top 4 km succession is constituted of highly conductive Oligocene and younger rocks of the Matera Formation and the Siwaliks, and recent sediments whereas the underlying > 5 km section is composed of sedimentary rocks of the Bahraich Group overlying the Archean basement. The high conductivity of sediments in conjunction with the low seismic velocity and large Vp/Vs obtained by receiver function analysis implies poor consolidation of sediments and thus high seismic hazard potential. The present results have implications for hydrocarbon exploration, hazard potential scenario of the central Ganga basin, and flexural strength of the Indian Plate.

Interpreting irregularity in small-scale, cyclical precipitation of halite-anhydrite couplets within the Pennsylvanian Paradox Formation, Paradox Basin, Utah

Science.gov (United States)

Marra, K. R.; Agena, W. F.; Dubiel, R. F.; Lee, M. W.; Pitman, J. K.

2012-12-01

The Pennsylvanian Paradox Formation (Hermosa Group) contains 33 documented evaporite cycles consisting of thick (6-240 m) halite successions interbedded with anhydrite, silty dolomite, and black shale. The evaporite deposits precipitated from marine brines under restricted circulation conditions in the Paradox Basin, a northwest-southeast trending asymmetrical trough formed adjacent to the Uncompahgre uplift, where periodic glacioeustatic sea-level fluctuations and intermittent meteoric water influxes altered salinity gradients. Each salt cycle contains rhythmically bedded halite-anhydrite couplets, in which anhedral to euhedral bottom-growth halite crystals are overlain by thin (mm-scale), subaqueously precipitated layers of anhydrite in the form of "snow-on-the-roof" texture. Discrete grains of sylvite, which are red due to hematite inclusions, locally occur as bands or aggregates throughout most salt packages. In order to delineate controls on high-frequency halite-anhydrite precipitation, the thickness of distinct couplets were measured in four salt cycles, two (Cycles 3 and 5) in the Cane Creek No.1 corehole and two (Cycles 5 and 13) in the Shafer No. 1 corehole. The cores were drilled approximately 8 km apart within the central portion of the basin near the crests of the Cane Creek and Shafer salt anticlines. The thickness of halite-anhydrite couplets ranges between 1-90 cm for all measured cycles, with the most commonly occurring thickness of approximately 3-4 cm. Despite the proximity of the two cores, the salt cycles in the Shafer No. 1 core are 12-15m thicker than in the Cane Creek No. 1 core, and individual couplets thicken within the middle (~20 m) of the salt section. In contrast, couplets thicken near the top of the halite bed in the Cane Creek No.1 core, which is most pronounced in Cycle 5. Locally disrupted and distorted laminae due to salt flowage, however, complicates some laminae measurements. The small-scale, cyclical pattern of halite

Limnological studies on the Pretoria Salt Pan, a hypersaline maar lake

CSIR Research Space (South Africa)

Ashton, PJ

1983-01-01

Full Text Available The Pretoria Salt pan is shallow and alkaline with pronounced mesothermy at a depth of between 0.55 and 0.7 metres. Secchi disc transparencies ranged from 7 to 19 cm. Endorheic or closed drainage basins are widely distributed in many climate...

GLAUBERITE-HALITE ASSOCIATION IN BOZKIR FORMATION (PLİOCENE, ÇANKIRI-ÇORUM BASİN, CENTRAL ANATOLİA, TURKEY

Directory of Open Access Journals (Sweden)

İLHAN SÖNMEZ

2015-06-01

Full Text Available Tertiary Çankırı – Çorum Basin is one of the biggest basin covering evaporitic formationsin the Central Anatolia. During borehole drills carried out in Bozkır Formation whichcontain Pliocene aged evaporites in the basin, a thick rocksalt (halite, NaCl deposit wasdetected that consisting of glauberite (Na2Ca(SO42 interlayers (sabhka synchronouswith sedimentation. Rocksalt bearing layers in Bozkır formation which was deposited inplaya-lake – sabhka environment, where seasonal changes are effective, were first definedas Tuz member in this study. Bozkır formation was divided into three zones in drillingscarried out in sabhka – playa -lake transitional environment. From bottom to top, these areordered as claystone-less anhydrite zone, rock salt-claystone-anhydrite-glauberite zone(Tuz member and claystone-gypsum-less anhydrite zone. Rocksalt was cut in thicknessesreaching 115 meters within Tuz member. Rocksalt (playa-lake which is mostly bedded andwhite, pale/dark gray colored is conformable with sedimentation and is low dipping. The1. Girifl

Permian Basin location recommendation report

International Nuclear Information System (INIS)

1983-09-01

Candidate study areas are screened from the Palo Duro and Dalhart Basin areas using data obtained from studies to date and criteria and specifications that consider: rock geometry; rock characteristics; human intrusion potential; surface characteristics; and environmental and socioeconomic conditions. Two preferred locations are recommended from among these areas for additional characterization to identify potential National Waste Terminal Storage (NWTS) salt repository sites. One location, in northeastern Deaf Smith County and southeastern Oldham County, is underlain by two salt units that meet the adopted screening specifications. The other location, in northcentral Swisher County, is underlain by one salt unit that meets the adopted screening specifications. Both locations have several favorable features, relative to surrounding areas, and no obviously undesirable characteristics. Both lie wholly on the Southern High Plains surface, are in relatively sparsely populated areas, contain no unique land use conflicts, and comprise large enough geographic areas to provide flexibility in site selection. Data gathered to date indicate that these locations contain salt units sufficient in thickness and in depth for the safe construction and operation of the underground facilities under consideration. 93 references, 34 figures, 6 tables

Occurrence of organohalogens at the Dead Sea Basin

Science.gov (United States)

Tubbesing, Christoph; Kotte, Karsten; Keppler, Frank; Krause, Torsten; Bahlmann, Enno; Schöler, Heinfried

2013-04-01

Most arid and semi-arid regions are characterized by evaporites, which are assured sources for volatile organohalogens (VOX) [1]. These compounds play an important role in tropospheric and stratospheric chemistry. The Dead Sea between Israel and Jordan is the world's most famous and biggest all-season water covered salt lake. In both countries chemical plants like the Dead Sea Works and the Arab Potash Company are located at the southern part of the Dead Sea and mine various elements such as bromine and magnesium. Conveying sea water through constructed evaporation pans multifarious salts are enriched and precipitated. In contrast, the Northern basin and main part of the Dead Sea has remained almost untouched by industrial salt production. Its fresh water supply from the Jordan River is constantly decreasing, leading to further increased salinity. During a HALOPROC campaign (Natural Halogenation Processes in the Environment) we collected various samples including air, soils, sediments, halophytic plants, ground- and seawater from the Northern and Southern basin of the Israeli side of the Dead Sea. These samples were investigated for the occurrence of halocarbons using different analytical techniques. Most samples were analyzed for volatile organohalogens such as haloalkanes using gas chromatography- mass spectrometry (GC-MS). Interestingly, there is a strong enrichment of trihalomethanes (THM), especially all chlorinated and brominated ones and also the iodinated compound dichloroiodomethane were found in the Southern basin. In addition, volatile organic carbons (VOC) such as ethene and some other alkenes were analyzed by a gas chromatography-flame ionisation detector (GC-FID) to obtain further information about potential precursors of halogenated compounds. Halophytic plants were investigated for their potential to release chloromethane and bromomethane but also for their stable carbon and hydrogen isotope composition. For this purpose, a plant chamber was

Geologic characterization of Cuvette Centrale petroleum systems Congo-DRC

Energy Technology Data Exchange (ETDEWEB)

Vicentelli, Maria Gabriela C.; Barbosa, Mauro; Rezende, Nelio G.A.M. [HRT Petroleum, Rio de Janeiro, RJ (Brazil)

2008-07-01

The Cuvette Centrale is an almost unexplored basin, which contains some petroleum system elements that indicate the presence of hydrocarbons. In this sense; this paper presents an exploratory alternative for this intracratonic basin. The interpretation of the limited gravimetric, magnetometric, geochemical and seismic available data allowed the identification of many huge structural features and also some areas with hydrocarbon potential for stratigraphic traps. The presence of several oil and gas seeps widespread around the Busira and Lokoro sub-basins indicate that at least one active petroleum system exist in the basin. Despite only four wells have been drilled in the basin, one of them presented oil shows during drilling. Geological correlations between Brazilian Paleozoic basins and Cuvette Centrale sedimentary sequences permitted to conclude that Cambro-Ordovician and Siluro-Devonian source rocks must be present and active in the Cuvette Centrale basin. The tectono-stratigraphic evolution history of the Cuvette Centrale from Neo proterozoic to Recent times shows extensional and compressional/transpressional alternating phases along the geological time. The most confident petroleum system expected in the Cuvette Centrale is characterized by the Cambrian Mamungi shale - source rock - and the Cambro-Ordovician. Upper Arenaceous Sequence - reservoirs, as observed in the MBandaka and Gilson wells and confirmed by surface geology in outcrops. Besides, other potential petroleum systems are expected to occur in the basin. One is characterized by the Neo proterozoic Itury Group source rock and reservoirs in the mature/over mature stage, the others are the Siluro-Devonian and Cretaceous source rocks and reservoirs, expected to occur with better maturity conditions only in the deeper parts of the basin. (author)

Active shortening, intermontane basin formation, and geomorphic evolution in an orogenic plateau: Central Puna Plateau, NW Argentina (24°37'S, 67°03'W)

Science.gov (United States)

Strecker, Manfred R.; Alonso, Ricardo N.; Bookhagen, Bodo; Freymark, Jessica; Pingel, Heiko

2017-04-01

The high-elevation Andean Plateau (Altiplano-Puna; 4km) is a first-order morphotectonic province of the Central Andes and constitutes the world's second largest orogenic plateau. While there are many unifying basin characteristics in this region, including internal drainage, semi-arid to arid climate and associated deposition of evaporites, there are notable differences between the northern and southern parts of the plateau. In contrast to the vast basins of the Altiplano (north) and incipient establishment of fluvial connectivity and sediment transport to the foreland, the Puna (south) comprises numerous smaller basins, bordered by reverse-fault bounded ranges up to 6 km high. The plateau is internally drained and fluvial connectivity with the foreland does not exist leading to thick sedimentary basin fills that comprise continental evaporites, volcanic and clastic deposits, typically between 3 and 5 km thick. However, repeated impacts of climate change and superposed tectonic activity in the southern plateau have resulted in further basin differentiation, abandonment or re-arrangement of fluvial networks and impacts on sediment transport. Here we report evidence for sustained contractional tectonic activity in the Pocitos Basin in the southern plateau. On the western margin of the basin fanning of dipping strata and regraded, steeply inclined gravel-covered pediment surfaces and wind gaps associated with gravel derived from distant sources in the west document late Tertiary to Pleistocene growth of an approximately N-S oriented and N plunging anticline. The growth of the eastern limb of this anticline has caused the isolation of a formerly more extensive basin. In addition, Late Pleistocene and Holocene lake shorelines and lacustrine deposits are tilted eastward along the same structure and InSAR measurements of deformed lake terraces document that the fold is growing. Despite widely reported extensional faulting in the southern Puna, we conclude (1) that the

γ-Aminobutyric acid transaminase deficiency impairs central carbon metabolism and leads to cell wall defects during salt stress in Arabidopsis roots.

Science.gov (United States)

Renault, Hugues; El Amrani, Abdelhak; Berger, Adeline; Mouille, Grégory; Soubigou-Taconnat, Ludivine; Bouchereau, Alain; Deleu, Carole

2013-05-01

Environmental constraints challenge cell homeostasis and thus require a tight regulation of metabolic activity. We have previously reported that the γ-aminobutyric acid (GABA) metabolism is crucial for Arabidopsis salt tolerance as revealed by the NaCl hypersensitivity of the GABA transaminase (GABA-T, At3g22200) gaba-t/pop2-1 mutant. In this study, we demonstrate that GABA-T deficiency during salt stress causes root and hypocotyl developmental defects and alterations of cell wall composition. A comparative genome-wide transcriptional analysis revealed that expression levels of genes involved in carbon metabolism, particularly sucrose and starch catabolism, were found to increase upon the loss of GABA-T function under salt stress conditions. Consistent with the altered mutant cell wall composition, a number of cell wall-related genes were also found differentially expressed. A targeted quantitative analysis of primary metabolites revealed that glutamate (GABA precursor) accumulated while succinate (the final product of GABA metabolism) significantly decreased in mutant roots after 1 d of NaCl treatment. Furthermore, sugar concentration was twofold reduced in gaba-t/pop2-1 mutant roots compared with wild type. Together, our results provide strong evidence that GABA metabolism is a major route for succinate production in roots and identify GABA as a major player of central carbon adjustment during salt stress. © 2012 Blackwell Publishing Ltd.

Physical characteristics of stream subbasins in the Pomme de Terre River Basin, west-central Minnesota

Science.gov (United States)

Lorenz, D.L.; Payne, G.A.

1994-01-01

Data describing the physical characteristics of stream subbasins upstream from selected points on streams in the Pomme de Terre River Basin, located in west-central Minnesota, are presented in this report. The physical characteristics are the drainage area of the subbasin, the percentage area of the subbasin covered only by lakes, the percentage area of the subbasin covered by both lakes and wetlands, the main-channel length, and the main-channel slope. The points on the stream include outlets of subbasins of at least 5 square miles, outfalls of sewage treatment plants, and locations of U.S. Geological Survey low-flow, high-flow, and continuous-record gaging stations.

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

Thermal conductivity and diffusivity of Permian Basin bedded salt at elevated pressure and temperature

International Nuclear Information System (INIS)

Durham, W.B.; Boro, C.O.; Beiriger, J.M.; Montan, D.N.

1983-10-01

Measurements of thermal conductivity and diffusivity were made on five core samples of bedded rock salt from the Permian Basin in Texas to determine its suitability as an underground nuclear waste repository. The sample size was 100 mm in diameter by 250 mm in length. Measurements were conducted under confining pressures ranging from 3.8 to 31.0 MPa and temperatures from room temperature to 473 K. Conductivity showed no dependence on confining pressure but evidenced a monotonic, negative temperature dependence. Four of the five samples showed conductivities clustered in a range of 5.6 +- 0.5 W/m.K at room temperature, falling to 3.6 +- 0.3 W/m.K at 473 K. These values are approximately 20% below those for pure halite, reflecting perhaps the 5 to 20%-nonhalite component of the samples. Diffusivity also showed a monotonic, negative temperature dependence, with four of the five samples clustered in a range of 2.7 +- 0.4 x 10 -6 m 2 /s at room temperature, and 1.5 +- 0.3 x 10 -6 m 2 /s at 473 K, all roughly 33% below the values for pure halite. One sample showed an unusually high conductivity (it also had the highest diffusivity), about 20% higher than the others; and one sample showed an unusually low diffusivity (it also had the lowest conductivity), roughly a factor of 2 lower than the others. 27 references, 8 figures, 4 tables

Primary aerosol and secondary inorganic aerosol budget over the Mediterranean Basin during 2012 and 2013

Science.gov (United States)

Guth, Jonathan; Marécal, Virginie; Josse, Béatrice; Arteta, Joaquim; Hamer, Paul

2018-04-01

In the frame of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx), we analyse the budget of primary aerosols and secondary inorganic aerosols over the Mediterranean Basin during the years 2012 and 2013. To do this, we use two year-long numerical simulations with the chemistry-transport model MOCAGE validated against satellite- and ground-based measurements. The budget is presented on an annual and a monthly basis on a domain covering 29 to 47° N latitude and 10° W to 38° E longitude. The years 2012 and 2013 show similar seasonal variations. The desert dust is the main contributor to the annual aerosol burden in the Mediterranean region with a peak in spring, and sea salt being the second most important contributor. The secondary inorganic aerosols, taken as a whole, contribute a similar level to sea salt. The results show that all of the considered aerosol types, except for sea salt aerosols, experience net export out of our Mediterranean Basin model domain, and thus this area should be considered as a source region for aerosols globally. Our study showed that 11 % of the desert dust, 22.8 to 39.5 % of the carbonaceous aerosols, 35 % of the sulfate and 9 % of the ammonium emitted or produced into the study domain are exported. The main sources of variability for aerosols between 2012 and 2013 are weather-related variations, acting on emissions processes, and the episodic import of aerosols from North American fires. In order to assess the importance of the anthropogenic emissions of the marine and the coastal areas which are central for the economy of the Mediterranean Basin, we made a sensitivity test simulation. This simulation is similar to the reference simulation but with the removal of the international shipping emissions and the anthropogenic emissions over a 50 km wide band inland along the coast. We showed that around 30 % of the emissions of carbonaceous aerosols and 35 to 60 % of the exported carbonaceous aerosols originates from the marine and

Assessment of a Salt Reduction Intervention on Adult Population Salt Intake in Fiji

Directory of Open Access Journals (Sweden)

Arti Pillay

2017-12-01

Full Text Available Reducing population salt intake is a global public health priority due to the potential to save lives and reduce the burden on the healthcare system through decreased blood pressure. This implementation science research project set out to measure salt consumption patterns and to assess the impact of a complex, multi-faceted intervention to reduce population salt intake in Fiji between 2012 and 2016. The intervention combined initiatives to engage food businesses to reduce salt in foods and meals with targeted consumer behavior change programs. There were 169 participants at baseline (response rate 28.2% and 272 at 20 months (response rate 22.4%. The mean salt intake from 24-h urine samples was estimated to be 11.7 grams per day (g/d at baseline and 10.3 g/d after 20 months (difference: −1.4 g/day, 95% CI −3.1 to 0.3, p = 0.115. Sub-analysis showed a statistically significant reduction in female salt intake in the Central Division but no differential impact in relation to age or ethnicity. Whilst the low response rate means it is not possible to draw firm conclusions about these changes, the population salt intake in Fiji, at 10.3 g/day, is still twice the World Health Organization’s (WHO recommended maximum intake. This project also assessed iodine intake levels in women of child-bearing age and found that they were within recommended guidelines. Existing policies and programs to reduce salt intake and prevent iodine deficiency need to be maintained or strengthened. Monitoring to assess changes in salt intake and to ensure that iodine levels remain adequate should be built into future surveys.

Bedrock morphology and structure, upper Santa Cruz Basin, south-central Arizona, with transient electromagnetic survey data

Science.gov (United States)

Bultman, Mark W.; Page, William R.

2016-10-31

susceptibilities of rocks found in the study area, and estimated natural remanent magnetic intensities and directions, reasonable geologic models can be built. This indicates that the depth to bedrock map is reason-able and geologically possible.Finally, CDTs derived from the 1998 Santa Cruz Basin transient electromagnetic survey were used to help identify basin structure and some physical properties of the basin fill in the study area. The CDTs also helped to confirm depth to bedrock estimates in the Santa Cruz Basin, in particular a region of elevated bedrock in the area of Potrero Canyon, and a deep basin in the location of the Arizona State Highway 82 microbasin. The CDTs identified many concealed faults in the study area and possibly indicate deep water-saturated clay-rich sediments in the west-central portion of the study area. These sediments grade to more sand-rich saturated sediments to the south with relatively thick, possibly unsaturated, sediments at the surface. Also, the CDTs may indicate deep saturated clay-rich sediments in the Highway 82 microbasin and in the Mount Benedict horst block from Proto Canyon south to the international border.

4D modeling of salt-sediment interactions during diapir evolution

Energy Technology Data Exchange (ETDEWEB)

Callot, J.P.; Rondon, D.; Letouzey, J. [IFP, Rueil Malmaison (France); Krajewski, P. [Gaz de France-PEG, Lingen (Germany); Rigollet, C. [Gaz de France, St. Denis la Plaine (France)

2007-09-13

We performed sand/silicon models imaged with X-ray tomography and reconstructed by 3D geomodelling for the study of (1) the interaction between host rock and salt diapir during diapir growth, and (2) the evolution of intra salt brittle rocks during diapir ascent. X-ray tomography is a non destructive imaging technique which allows us to follow the 4D evolution of the analogue model. Salt is modelled by Newtonian silicone putty and the internal rock layer, as well as the sedimentary host rock, by a granular Mohr-Coulomb material, generally coryndon. The analogue models are then compared to natural examples, the evolution of which is obtained through 3D restoration of the structures. (1) A 4D evolutionary scenario for a salt diapir development was originally proposed by Trusheim (1960) and discussed later on by Vendeville (1999) among others (Ge et al., 1997; Zirngast et al., 1996). This scenario is reproduced through analogue models to test the relative importance of (1) extensional tectonics, (2) sediment progradations, and (3) source layer depletion and rim-syncline touchdown, in the evolution of a diapir. The comparison of our results with the restored natural analogue shows that the main parameter remains (1) the rim-syncline touchdown and (2) the unloading of the diapir due to erosion. The latter accounts for a drop in strength necessary to allow for the flank rotation and down building of the diapir. Extensional stresses and sediment progradations will also amplify the halokinesis. (2) Salt diapirs from the Middle East or in Southern Permian Basin petroleum province show exotic blocks at outcrop and in salt mines, known as 'stringers' in subsurface data, usually composed of anhydrite, dolomite, marls or carbonates. These stringers, which constitute major structures inside the salt diapir, can reach a few km in size and originate from pre-existing brittle rock layers embedded in the salt layer. Stringers of the Ara carbonate within the Precambrian

Real-time management of water quality in the San Joaquin River Basin, California.

Energy Technology Data Exchange (ETDEWEB)

Quinn, N.W.T.; Karkoski, J.

1997-09-01

In the San Joaquin River Basin, California, a realtime water quality forecasting model was developed to help improve the management of saline agricultural and wetland drainage to meet water quality objectives. Predicted salt loads from the water quality forecasting model, SJRIODAY, were consistently within +- 11 percent of actual, within +- 14 percent for seven-day forecasts, and with in +- 26 percent for 14-day forecasts for the 16-month trial period. When the 48 days dominated by rainfall/runoff events were eliminated from the data set, the error bar decreased to +- 9 percent for the model and +- 11 percent and +- 17 percent for the seven-day and 14-day forecasts, respectively. Constraints on the use of the model for salinity management on the San Joaquin River include the number of entities that control or influence water quality and the lack of a centralized authority to direct their activities. The lack of real-time monitoring sensors for other primary constituents of concern, such as selenium and boron, limits the application of the model to salinity at the present time. A case study describes wetland drainage releases scheduled to coincide with high river flows and significant river assimilative capacity for salt loads.

Structural characteristics of epicentral areas in Central Europe: study case Cheb Basin (Czech Republic)

Science.gov (United States)

Bankwitz, P.; Schneider, G.; Kämpf, H.; Bankwitz, E.

2003-03-01

The earthquake distribution pattern of Central Europe differs systematically from the neighbouring areas of NW and southern Europe regarding the fault plane kinematics. Within a belt between the French Massif Central and the northern part of the Bohemian Massif (1000 km) sinistral faulting along N-S zones dominates on the contrary to the Alps and their foreland with common bookshelf shears. One of the prominent N-S structures is the Regensburg-Leipzig-Rostock Zone (A) with several epicentral areas, where the main seismic center occurs in the northern Cheb Basin (NW Bohemia). The study demonstrates new structural results for the swarm-quake region in NW-Bohemia, especially for the Nový Kostel area in the Cheb Basin. There the N-S-trending newly found Počatky-Plesná zone (PPZ) is identical with the main earthquake line. The PPZ is connected with a mofette line between Hartušov and Bublák with evidence for CO 2 degassing from the subcrustal mantle. The morphologically more prominent Mariánské Lázně fault (MLF) intersects the PPZ obliquely under an acuate angle. In the past the MLF was supposed to be the tectonic structure connected with the epicentral area of Nový Kostel. But evidence from the relocated hypocentres along the PPZ (at 7-12 kms depth) indicate that the MLF is seismically non-active. Asymmetric drainage patterns of the Cheb Basin are caused by fault related movement along Palaeozoic basement faults which initiate a deformation of the cover (Upper Pliocene to Holocene basin filling). The PPZ forms an escarpment in Pliocene and Pleistocene soft rock and is supposingly acting as an earthquake zone since late Pleistocene time. The uppermost Pleistocene of 0.12-0.01 Ma deposited only in front of the fault scarp dates the fault activity. The crossing faults envelope crustal wedges under different local stress conditions. Their intersection line forms a zone beginning at the surface near Nový Kostel, dipping south with increasing depth, probably down

Process-based management approaches for salt desert shrublands dominated by downy brome

Science.gov (United States)

Downy brome grass (Bromus tectorum L.) invasion has severely altered key ecological processes such as disturbance regimes, soil nutrient cycling, community assembly, and successional pathways in semi-arid Great Basin salt desert shrublands. Restoring the structure and function of these severly alte...

Interpreting Fracture Patterns in Sandstones Interbedded with Ductile Strata at the Salt Valley Anticline, Arches National Park, Utah

OpenAIRE

Lorenz, John C.; Cooper, Scott P.

2001-01-01

Sandstones that overlie or that are interbedded with evaporitic or other ductile strata commonly contain numerous localized domains of fractures, each covering an area of a few square miles. Fractures within the Entrada Sandstone at the Salt Valley Anticline are associated with salt mobility within the underlying Paradox Formation. The fracture relationships observed at Salt Valley (along with examples from Paleozoic strata at the southern edge of the Holbrook basin in northeastern Arizona, a...

Highly calcareous lacustrine soils in the Great Konya Basin, Turkey

NARCIS (Netherlands)

Meester, de T.

1971-01-01

The Great Konya Basin is in the south of the Central Anatolian Plateau in Turkey. It is a depression without outlet to the sea. The central part of the Basin is the floor of a former Pleistocene lake, the Ancient Konya Lake. This area, called the Lacustrine
Plain, has highly calcareous

Lesula: a new species of Cercopithecus monkey endemic to the Democratic Republic of Congo and implications for conservation of Congo's central basin.

Directory of Open Access Journals (Sweden)

John A Hart

Full Text Available In June 2007, a previously undescribed monkey known locally as "lesula" was found in the forests of the middle Lomami Basin in central Democratic Republic of Congo (DRC. We describe this new species as Cercopithecus lomamiensis sp. nov., and provide data on its distribution, morphology, genetics, ecology and behavior. C. lomamiensis is restricted to the lowland rain forests of central DRC between the middle Lomami and the upper Tshuapa Rivers. Morphological and molecular data confirm that C. lomamiensis is distinct from its nearest congener, C. hamlyni, from which it is separated geographically by both the Congo (Lualaba and the Lomami Rivers. C. lomamiensis, like C. hamlyni, is semi-terrestrial with a diet containing terrestrial herbaceous vegetation. The discovery of C. lomamiensis highlights the biogeographic significance and importance for conservation of central Congo's interfluvial TL2 region, defined from the upper Tshuapa River through the Lomami Basin to the Congo (Lualaba River. The TL2 region has been found to contain a high diversity of anthropoid primates including three forms, in addition to C. lomamiensis, that are endemic to the area. We recommend the common name, lesula, for this new species, as it is the vernacular name used over most of its known range.

Cenozoic Structural and Stratigraphic Evolution of the Ulukışla and Sivas Basins (Central and Eastern Turkey)

Science.gov (United States)

Gürer, Derya; Darin, Michael H.; van Hinsbergen, Douwe J. J.; Umhoefer, Paul J.

2017-04-01

Because subduction is a destructive process, the surface record of subduction-dominated systems is naturally incomplete. Sedimentary basins may hold the most complete record of processes related to subduction, accretion, collision, and ocean closure, and thus provide key information for understanding the kinematic evolution of orogens. In central and eastern Anatolia, the Late Cretaceous-Paleogene stratigraphic record of the Ulukışla and Sivas basins supports the hypothesis that these once formed a contiguous basin. Importantly, their age and geographic positions relative to their very similar basement units and ahead of the Arabian indenter provide a critical record of pre-, syn- and post-collisional processes in the Anatolian Orogen. The Ulukışla-Sivas basin was dissected and translated along the major left-lateral Ecemiş fault zone. Since then, the basins on either side of the fault evolved independently, with considerably more plate convergence accommodated to the east in the Sivas region (eastern Anatolia) than in the Ulukışla region (central Anatolia). This led to the deformation of marine sediments and underlying ophiolites and structural growth of the Sivas Fold-and-Thrust Belt (SSFTB) since latest Eocene time, which played a major role in marine basin isolation and disconnection, along with a regionally important transition to continental conditions with evaporite deposition starting in the early Oligocene. We use geologic mapping, fault kinematic analysis, paleomagnetism, apatite fission track (AFT) thermochronology, and 40Ar/39Ar geochronology to characterize the architecture, deformation style, and structural evolution of the region. In the Ulukışla basin, dominantly E-W trending normal faults became folded or inverted due to N-S contraction since the Lutetian (middle Eocene). This was accompanied by significant counter-clockwise rotations, and post-Lutetian burial of the Niǧde Massif along the transpressional Ecemiş fault zone. Since Miocene

Effect of basement structure and salt tectonics on deformation styles along strike: An example from the Kuqa fold-thrust belt, West China

Science.gov (United States)

Neng, Yuan; Xie, Huiwen; Yin, Hongwei; Li, Yong; Wang, Wei

2018-04-01

The Kuqa fold-thrust belt (KFTB) has a complex thrust-system geometry and comprises basement-involved thrusts, décollement thrusts, triangle zones, strike-slip faults, transpressional faults, and pop-up structures. These structures, combined with the effects of Paleogene salt tectonics and Paleozoic basement uplift form a complex structural zone trending E-W. Interpretation and comprehensive analysis of recent high-quality seismic data, field observations, boreholes, and gravity data covering the KFTB has been performed to understand the characteristics and mechanisms of the deformation styles along strike. Regional sections, fold-thrust system maps of the surface and the sub-salt layer, salt and basement structure distribution maps have been created, and a comprehensive analysis of thrust systems performed. The results indicate that the thrust-fold system in Paleogene salt range can be divided into five segments from east to west: the Kela-3, Keshen, Dabei, Bozi, and Awate segments. In the easternmost and westernmost parts of the Paleogene salt range, strike-slip faulting and basement-involved thrusting are the dominant deformation styles, as basement uplift and the limits of the Cenozoic evaporite deposit are the main controls on deformation. Salt-core detachment fold-thrust systems coincide with areas of salt tectonics, and pop-up, imbricate, and duplex structures are associated with the main thrust faults in the sub-salt layer. Distribution maps of thrust systems, basement structures, and salt tectonics show that Paleozoic basement uplift controlled the Paleozoic foreland basin morphology and the distribution of Cenozoic salt in the KFTB, and thus had a strong influence on the segmented structural deformation and evolution of the fold-thrust belt. Three types of transfer zone are identified, based on the characteristics of the salt layer and basement uplift, and the effects of these zones on the fault systems are evaluated. Basement uplift and the boundary of

Expansion of the South China Sea basin: Constraints from magnetic anomaly stripes, sea floor topography, satellite gravity and submarine geothermics

Directory of Open Access Journals (Sweden)

Xuezhong Yu

2017-01-01

Full Text Available The widely distributed E–W-trending magnetic anomaly stripes in the central basin and the N–E-trending magnetic anomaly stripes in the southwest sub-basin provide the most important evidence for Neogene expansion of the South China Sea. The expansion mechanism remains, however, controversial because of the lack of direct drilling data, non-systematic marine magnetic survey data, and irregular magnetic anomaly stripes with two obvious directions. For example, researchers have inferred different ages and episodes of expansion for the central basin and southwest sub-basin. Major controversy centers on the order of basinal expansion and the mechanism of expansion for the entire South China Sea basin. This study attempts to constrain these problems from a comprehensive analysis of the seafloor topography, magnetic anomaly stripes, regional aeromagnetic data, satellite gravity, and submarine geothermics. The mapped seafloor terrain shows that the central basin is a north-south rectangle that is relatively shallow with many seamounts, whereas the southwest sub-basin is wide in northeast, gradually narrows to the southwest, and is relatively deeper with fewer seamounts. Many magnetic anomaly stripes are present in the central basin with variable dimensions and directions that are dominantly EW-trending, followed by the NE-, NW- and NS-trending. Conversely such stripes are few in the southwest sub-basin and mainly NE-trending. Regional magnetic data suggest that the NW-trending Ailaoshan-Red River fault extends into the South China Sea, links with the central fault zone in the South China Sea, which extends further southward to Reed Tablemount. Satellite gravity data show that both the central basin and southwest sub-basin are composed of oceanic crust. The Changlong seamount is particularly visible in the southwest sub-basin and extends eastward to the Zhenbei seamount. Also a low gravity anomaly zone coincides with the central fault zone in the sub-basin

The Tunas Formation (Permian) in the Sierras Australes foldbelt, east central Argentina: evidence for syntectonic sedimentation in a foreland basin

Science.gov (United States)

Lopez-Gamundi, O. R.; Conaghan, P. J.; Rossello, E. A.; Cobbold, P. R.

1995-04-01

The Tunas Formation, extensively exposed in the Sierras Australes foldbelt of eastern central Argentina, completes the sedimentation of the Gondwanan (Late Carboniferous-Permian) sequence, locally known as the Pillahuincó Group. The underlying units of the Group show an integrated depositional history which can be explained in terms of glaciomarine sedimentation (Sauce Grande Formation) and postglacial transgression (Piedra Azul and Bonete Formations). This succession also has a rather uniform quartz-rich, sand-sized composition indicative of a cratonic provenance from the Tandilia Massif to the northeast. Early to Late Permian deformation folded and thrusted the southwestern basin margin (Sierras Australes) and triggered the deposition of a 1,500 m — thick, synorogenic prograding wedge, the Tunas Formation, in the adjacent foreland basin (Sauce Grande or Claromecó Basin). Sandstone detrital modes for the Tunas deposits show moderate to low contents of quartz and abundant lithics, mostly of volcanic and metasedimentary origin. Paleocurrents are consistently from the SW. Tuffs interbedded with sandstones in the upper half of Tunas Formation (Early — early Late? Permian) are interpreted as being derived from volcanic glass-rich tuffs settled in a body of water. Extensive rhyolitic ignimbrites and consanguineous airborne tuffaceous material erupted in the northern Patagonian region during that period. The age constraints and similarities in composition between these volcanics and the tuffaceous horizons present in the Sauce Grande, Parana and Karoo Basins suggest a genetic linkage between these two episodes. The intimate relationship between volcanic activity inboard of the paleo-Pacific margin, deformation in the adjacent orogenic belt and subsidence and sedimentation in the contiguous foreland basin constitutes a common motif in the Sauce Grande and Karoo Basins of southwestern Gondwana.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2015

Science.gov (United States)

Beman, Joseph E.; Bryant, Christina F.

2016-10-27

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is hydrologically defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift between San Acacia to the south and Cochiti Lake to the north. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began treatment and distribution of surface water from the Rio Grande through the San Juan-Chama Drinking Water Project. A 20-percent population increase in the basin from 1990 to 2000 and a 22-percent population increase from 2000 to 2010 may have resulted in an increased demand for water in areas within the basin.An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the Albuquerque Basin. In 1983, this network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly. The network currently (2015) consists of 124 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the ABCWUA, currently (2015) measures and reports water levels from the 124 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 124 sites through water year 2015 (October 1, 2014, through September 30, 2015).

Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. A report on the progress of nuclear isolation feasibility studies, 1980. Annual report, October 1, 1979-September 30, 1980

International Nuclear Information System (INIS)

Gustavson, T.C.; Bassett, R.L.; Finley, R.J.

1981-01-01

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 and the State of Texas, is conducting a long-term program to gather and interpret all geologic and hydrologic information necessary for description, delineation, and evaluation of salt-bearing and related strata in the Palo Duro and Dalhart Basins of the Texas Panhandle. The program in FY 1980 was divided into five broad research tasks, which were addressed by a surficial analysis and shallow stratigraphy group, a hydrology and geochemistry group, a basin analysis group, a host-rock analysis group, and a seismicity and tectonic environment group. The surficial analysis and shallow stratigraphy group has collected remotely sensed, surface and subsurface data to describe land resources, surface processes, and rates and styles of geomorphic development. The hydrology and geochemistry group has continued analysis of shallow and deep fluid circulation within the basins and has initiated studies of rock and fluid geochemistry within the salt-bearing units. The basin analysis group has characterized the major salt-bearing stratigraphic units within the basins and has assessed the potential for generating and trapping hydrocarbons within the basins. Concurrently, the host-rock analysis group has continued a study of cores from two drilling sites for analysis of salt and other lithologic units within the cores. The newly formed seismicity and tectonic environment group has initiated studies of deep-basement structure and tetonic development of the basin and has made an analysis of surface fracture systems. This paper, a summary of progress during FY 1980, presents principal conclusions and reviews methods used and types of data and maps generated

Regional hydrology of the Dolores River Basin, eastern Paradox Basin, Colorado and Utah

International Nuclear Information System (INIS)

Weir, J.E. Jr.; Maxfield, E.B.; Zimmerman, E.A.

1983-01-01

The Dolores River Basin, is in the eastern part of the Paradox Basin and includes the eastern slope of the La Sal Mountains, the western slopes of the Rico and La Plata Mountains, and the southwest flank of the Uncompahgre Plateau. The climate of this area is more humid than most of the surrounding Colorado Plateau region. Precipitation ranges from slightly 200 mm/yr to 1000 mm/yr; the estimated volume of water falling on the area is 4000 x 10 6 cm 3 /yr. Of this total, about 600 x 10 6 cm 3 /yr is runoff; 190 x 10 6 cm 3 /yr recharges the upper ground-water system; and an estimated 55 x 10 6 cm 3 returns to the atmosphere via evapotranspiration from stream valleys. The remainder evaporates. Principal hydrogeologic units are permeable sandstone and limestone and nearly impermeable salt (halitic) deposits. Structurally, the area is dominated by northwest-trending salt anticlines and contiguous faults paralleled by synclinal structures. The Uncompahgre Plateau lies along the north and northeast sides of the area. The instrusive masses that form the La Sal Mountains are laccoliths with bysmaliths and other complex intrusive forms comprising, in gross form, moderately faulted omal structures. Intrusive rocks underlie the La Plata and Rico Mountains along the southeastern edge of the area. These geologic structures significantly modify ground-water flow patterns in the upper ground-water system, but have no conspicuous effect on the flow regime in the lower ground-water system. The water in the upper ground-water system generally is fresh except where it is affected by evaporite dissolution from salt anticlines. The water of the lower ground-water system is slightly saline to briny. Water quality of the Dolores River is slightly saline to fresh, based on dissolved chemical constituents; some of the smaller tributaries of the river have saline water

Modeling and assessing the function and sustainability of natural patches in salt-affected agro-ecosystems: Application to tamarisk (Tamarix chinensis Lour.) in Hetao, upper Yellow River basin

Science.gov (United States)

Ren, Dongyang; Xu, Xu; Ramos, Tiago B.; Huang, Quanzhong; Huo, Zailin; Huang, Guanhua

2017-09-01

Relatively low-lying zones of natural vegetation within irrigated areas are not only carriers of biodiversity but also dry drainage areas of excess water and salts applied to nearby croplands. It is thus useful to have a correct understanding of the soil water-salt dynamics and plant water use for keeping the sustainability of those natural areas. The HYDRUS-dualKc model that couples the HYDRUS-1D model with the FAO-56 dualKc approach was extended to simulate the eco-hydrological processes in natural patches of Hetao Irrigation District (Hetao), upper Yellow River basin. Field experiments were conducted in a tamarisk (Tamarix chinensis Lour.) dominated area during the growing seasons of 2012 and 2013. The model was calibrated and validated using the two-year experimental data, and applied to analyze the water and salt dynamics and the tamarisk water consumption for the present situation. Then, various groundwater depth (i.e. the depth from groundwater surface to water table, GWD) scenarios were simulated while considering the fluctuating and constant regimes of GWD changes, as well as variations of the rooting depth. Results indicated that this natural land functioned efficiently as a drainage area for subsurface flow and excess salt from surrounding croplands. However, the present GWDs were too shallow leading to high soil evaporation and severe salt stress. The soil evaporation accounted for 50% of the total evapotranspiration (ETa) while root zone salt storage increased about 50% during growing seasons. On the basis of scenario analysis, an optimum groundwater depth of 140-200 cm with smaller fluctuation was suggested for the growing seasons of natural patches. In addition, tamarisk growth could be largely improved if the roots can grow deeper with water table decline in the future. We demonstrated that monitoring and modeling could be used to support the development of water management strategies in Hetao aimed at conserving water while sustaining local

Multielemental analysis of ferromanganese nodules from Central Indian Ocean Basin by PIXE

International Nuclear Information System (INIS)

Dutta, R. K.; Vijayan, V.; Ghosh, S.; Chakravortty, V.

1997-01-01

Ferromanganese nodules found on the Ocean bed are complex heterogeneous mixtures of several components. Two nodules from Central Indian Ocean Basin (CIOB) were analysed by proton induced X-ray emission (PIXE) technique using 3UD Tandem pelletron. The precision and the accuracy of this technique for chemical analyses has been confirmed by analysing USGS Geological Standards. Thick sample targets were bombarded by 3 MeV protons for the multielemental analysis. GUPIX-96 software was used for spectral data analysis. Quantitative estimate of K, Ca, Tl, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Ba, Ce, Tl and Pb has been ascertained. The occurrence of Ga, Ge, Rb and Zr in nodules from this region is reported for the first time. The role of manganese and iron oxide phases in determining the uptake of various trace elements from ocean water and bottom sediment pore water has been discussed. (author)

Heat flow in Railroad Valley, Nevada and implications for geothermal resources in the south-central Great Basin

Science.gov (United States)

Williams, C.F.; Sass, J.H.

2006-01-01

The Great Basin is a province of high average heat flow (approximately 90 mW m-2), with higher values characteristic of some areas and relatively low heat flow (characteristic of an area in south-central Nevada known as the Eureka Low. There is hydrologie and thermal evidence that the Eureka Low results from a relatively shallow, hydrologically controlled heat sink associated with interbasin water flow in the Paleozoic carbonate aquifers. Evaluating this hypothesis and investigating the thermal state of the Eureka Low at depth is a high priority for the US Geological Survey as it prepares a new national geothermal resource assessment. Part of this investigation is focused on Railroad Valley, the site of the largest petroleum reservoirs in Nevada and one of the few locations within the Eureka Low with a known geothermal system. Temperature and thermal conductivity data have been acquired from wells in Railroad Valley in order to determine heat flow in the basin. The results reveal a complex interaction of cooling due to shallow ground-water flow, relatively low (49 to 76 mW m-2) conductive heat flow at depth in most of the basin, and high (up to 234 mW m-2) heat flow associated with the 125??C geothermal system that encompasses the Bacon Flat and Grant Canyon oil fields. The presence of the Railroad Valley geothermal resource within the Eureka Low may be reflect the absence of deep ground-water flow sweeping heat out of the basin. If true, this suggests that other areas in the carbonate aquifer province may contain deep geothermal resources that are masked by ground-water flow.

Saline Playas on Qinghai-Tibet Plateau as Mars Analog for the Formation-Preservation of Hydrous Salts and Biosignatures

Science.gov (United States)

Wang, A.; Zheng, M.; Kong, F.; Sobron, P.; Mayer, D. P.

2010-12-01

Qinghai-Tibet (QT) Plateau has the highest average elevation on Earth (~ 4500 m, about 50-60% of atmospheric pressure at sea-level). The high elevation induces a tremendous diurnal (and seasonal) temperature swing caused by high level of solar irradiation during the day and low level of atmospheric insulation during the evening. In addition, the Himalaya mountain chain (average height >6100 m) in the south of the QT Plateau largely blocks the pathway of humid air from the Indian Ocean, and produces a Hyperarid region (Aridity Index, AI ~ 0.04), the Qaidam Basin (N32-35, E90-100) at the north edge of the QT Plateau. Climatically, the low P, T, large ΔT, high aridity, and high UV radiation all make the Qaidam basin to be one of the most similar places on Earth to Mars. Qaidam basin has the most ancient playas (up to Eocene) and the lakes with the highest salinity on QT Plateau. More importantly, Mg-sulfates appear in the evaporative salts within the most ancient playas (Da Langtang) at the northwest corner of Qaidam basin, which mark the final stage of the evaporation sequence of brines rich in K, Na, Ca, Mg, Fe, C, B, S, and Cl. The evaporation minerals in the saline playas of Qaidam basin, their alteration and preservation under hyperarid conditions can be an interesting analog for the study of Martian salts and salty regolith. We conducted a field investigation at Da Langtan playa in Qaidam basin, with combined remote sensing (ASTER on board of NASA’s Terra satellite, 1.656, 2.167, 2.209, 2.62, 2.336, 2.40 µm), in situ sensing of a portable NIR spectrometer (WIR, 1.25-2.5 µm continuous spectral range), and the laboratory analyses of collected samples from the field (ASD spectrometer, 0.4 -2.5 µm, and Laser Raman spectroscopy). The results indicate that the materials contributing the high albedo layers in playa deposits are carbonate-gypsum-bearing surface soils, salt-clay-bearing exhaumed Pleistocene deposits, dehydrated Na-sulfates, hydrous Mg

Late Quaternary glaciation history of monsoon-dominated Dingad basin, central Himalaya, India

Science.gov (United States)

Shukla, Tanuj; Mehta, Manish; Jaiswal, Manoj K.; Srivastava, Pradeep; Dobhal, D. P.; Nainwal, H. C.; Singh, Atul K.

2018-02-01

The study presents the Late Quaternary glaciation history of monsoon-dominated Dokriani Glacier valley, Dingad basin, central Himalaya, India. The basin is tested for the mechanism of landforms preservation in high relief and abundant precipitation regimes of the Higher Himalaya. Field geomorphology and remote sensing data, supported by Optical Stimulated Luminescence (OSL) dating enabled identification of five major glacial events of decreasing magnitude. The oldest glacial stage, Dokriani Glacial Stage I (DGS-I), extended down to ∼8 km (2883 m asl) from present-day snout (3965 m asl) followed by other four glaciations events viz. DGS-II, DGS-III, DGS-IV and DGS-V terminating at ∼3211, 3445, 3648 and ∼3733 m asl respectively. The DGS-I glaciation (∼25-∼22 ka BP) occurred during early Marine Isotope Stage (MIS) -2, characterized as Last Glacial Maximum (LGM) extension of the valley. Similarly, DGS-II stage (∼14-∼11 ka BP) represents the global cool and dry Older Dryas and Younger Dryas event glaciation. The DGS-III glaciation (∼8 ka BP) coincides with early Holocene 8.2 ka cooling event, the DGS-IV glaciations (∼4-3.7 ka BP) corresponds to 4.2 ka cool and drier event, DGS-V (∼2.7-∼1 ka BP) represents the cool and moist late Holocene glacial advancement of the valley. This study suggests that the Dokriani Glacier valley responded to the global lowering of temperature and variable precipitation conditions. This study also highlights the close correlation between the monsoon-dominated valley glaciations and Northern Hemisphere cooling events influenced by North Atlantic climate.

Chemical modeling of nuclear waste repositories in the salt repository project

International Nuclear Information System (INIS)

Jansen, G.; Raines, G.E.; Kircher, J.F.; Hubbard, N.

1985-01-01

Salt deposits contain small amounts of water as brine in fluid inclusions in halite and in hydrous minerals, e.g., clays, kieserite (MgSO 4 . H 2 O) and carnallite (KMgCl 3 . 6H 2 O). For the candidate salt deposits, the total amounts of water as volume % brine are: Palo Duro Basin, Texas, approximately 1.8; Paradox Basin, Utah, approximately 5.0 for the carnallite-marker zone, and less than approximately 0.5 below this zone; Gulf Coast salt domes, less than 0.15. For the Palo Duro and Paradox salt, the brines are Mg-rich (approximately 20,000 mg/L to approximately 100,000 mg/L) and sometimes Ca-rich (up to about 20,000 mg/L) NaCl brines. Brine migration calculations have been made using calculations of the time-variant thermal gradient around the waste packages and conservatively high brine volumes in the salt (5.0 volume % for the Texas and Utah sites and 0.5 volume % for the Gulf Coast) as input data. The maximum amounts of brine that eventually migrate to each waste package are about 1.0m 3 (for 5.0 volume % brine) and 0.2m 3 (for 0.5 volume % brine). With current conceptual designs for waste package overpacks (10 to 15 cm thick low-carbon steel), the waste package is not breached by uniform corrosion within 10,000 years. In brines this material thus far shows only uniform corrosion. For the expected conditions, where the brine is provided solely by brine migration, the brine is consumed by reaction with the iron of the overpack nearly as fast as it migrates to the waste package. Therefore, for the expected conditions, data about corrosion rates, radiolysis, etc., are not important. However, it is essential that accurate volumes of in-migrating brine can be calculated

Supra-salt normal fault growth during the rise and fall of a diapir: Perspectives from 3D seismic reflection data, Norwegian North Sea

Science.gov (United States)

Tvedt, Anette B. M.; Rotevatn, Atle; Jackson, Christopher A.-L.

2016-10-01

Normal faulting and the deep subsurface flow of salt are key processes controlling the structural development of many salt-bearing sedimentary basins. However, our detailed understanding of the spatial and temporal relationship between normal faulting and salt movement is poor due to a lack of natural examples constraining their geometric and kinematic relationship in three-dimensions. To improve our understanding of these processes, we here use 3D seismic reflection and borehole data from the Egersund Basin, offshore Norway, to determine the structure and growth of a normal fault array formed during the birth, growth and decay of an array of salt structures. We show that the fault array and salt structures developed in response to: (i) Late Triassic-to-Middle Jurassic extension, which involved thick-skinned, sub-salt and thin-skinned supra-salt faulting with the latter driving reactive diapirism; (ii) Early Cretaceous extensional collapse of the walls; and (iii) Jurassic-to-Neogene, active and passive diapirism, which was at least partly coeval with and occurred along-strike from areas of reactive diapirism and wall collapse. Our study supports physical model predictions, showcasing a three-dimensional example of how protracted, multiphase salt diapirism can influence the structure and growth of normal fault arrays.

Quantitative and qualitative vulnerability of the Makutupora basin aquifer Dodoma, central Tanzania

International Nuclear Information System (INIS)

Kongola, L.R.E.

1999-01-01

The rapid development of Dodoma town has raised demand for water for domestic, irrigation and industrial use. Uncontrolled human activities pose threat of contamination of the well field and damage to recharge areas of Makutupora basin. Monitoring data collected over the years indicate that the basin is overpumped in dry years and that peripheral boreholes register high nitrate levels from nearby settlements and intensive use of agrochemicals on farms within the basin

Native aluminium (spherules and particles) in the central Indian Basin sediments: Implications on the occurrence of hydrothermal events

Digital Repository Service at National Institute of Oceanography (India)

Iyer, S.D; Mascarenhas-Pereira, M.B.L.; Nath, B.N

. Conference report. J. Geol. Soc. Am., 136, 621-626. Das, P., Iyer, S.D., Kodagali, V.N., Krishna, K.S., 2005. A new insight into the distribution and origin of seamounts in the Central Indian Ocean Basin. Mar. Geod., 28, 259-269. Davydov, M... Ridge, 26o N): Space trotter, guest from mantle, or a widespread mineral, connected with serpentinization? J. Geophys. Res., 111, B05103, doi:10.1029/ 2005JB003955. Dekov, V.M., Mandova, E.D., Dimitrov, K.C., Rekkalov, K.N., 1995. Native aluminium...

Rodents from the Upper Miocene Tuğlu Formation (Çankırı Basin, Central Anatolia, Turkey)

OpenAIRE

Joniak, Peter; de Bruijn, Hans

2015-01-01

The upper Miocene assemblages of rodents collected from two layers of the type section of the Tuğlu Formation (Çankırı Basin, Central Anatolia, Turkey) are described. The assemblage from the lower level is considerably less diverse than that from the upper level. It contains Progonomys together with Megacricetodon, which is a very unusual association. The assemblage from the upper layer shows a relatively high diversity with four species of Gliridae instead of only one in the lower layer. Apa...

Geologic characterization report for the Paradox Basin Study Region, Utah Study Areas. Volume 6: Salt Valley

Science.gov (United States)

1984-12-01

Surface landforms in the Salt Valley Area are generally a function of the Salt Valley anticline and are characterized by parallel and subparallel cuestaform ridges and hogbacks and flat valley floors. The most prominent structure in the Area is the Salt Valley anticline. Erosion resulting from the Tertiary uplift of the Colorado Plateau led to salt dissolution and subsequent collapse along the crest of the anticline. Continued erosion removed the collapse material, forming an axial valley along the crest of the anticline. Paleozoic rocks beneath the salt bearing Paradox Formation consist of limestone, dolomite, sandstone, siltstone and shale. The salt beds of the Paradox formation occur in distinct cycles separated by an interbed sequence of anhydrite, carbonate, and clastic rocks. The Paradox Formation is overlain by Pennsylvanian limestone; Permian sandstone; and Mesozoic sandstone, mudstone, conglomerate and shale. No earthquakes have been reported in the area during the period of the historic record and contemporary seismicity appears to be diffusely distributed, of low level and small magnitude. The upper unit includes the Permian strata and upper Honaker trail formation.

(Plio-)Pleistocene alluvial-lacustrine basin infill evolution in a strike-slip active zone (Northern Andes, Western-Central Cordilleras, Colombia)

OpenAIRE

SUTER, F.; NEUWERTH, R.; GORIN, G.; GUZMÁN, C.

2009-01-01

The (Plio)-Pleistocene Zarzal Formation was deposited in the Cauca Depression and Quindío-Risaralda Basin between the Western and Central Cordilleras (Northern Andes). This area is structurally located on the transcurrent Romeral Fault System (RFS). Because of the interaction between the Nazca plate and the Chocó-Panamá block (an active indenter), the RFS strike-slip component changes direction around the study zone (dextral in the south, senestral in the north). Zarzal sediments are the olde...

Flood-tracking chart for the Withlacoochee and Little River Basins in south-central Georgia and northern Florida

Science.gov (United States)

Gotvald, Anthony J.; McCallum, Brian E.; Painter, Jaime A.

2014-01-01

The U.S. Geological Survey (USGS), in cooperation with other Federal, State, and local agencies, operates a flood-monitoring system in the Withlacoochee and Little River Basins. This system is a network of automated river stage stations (ten are shown on page 2 of this publication) that transmit stage data through satellite telemetry to the USGS in Atlanta, Georgia and the National Weather Service (NWS) in Peachtree City, Georgia. During floods, the public and emergency response agencies use this information to make decisions about road closures, evacuations, and other public safety issues. This Withlacoochee and Little River Basins flood-tracking chart can be used by local citizens and emergency response personnel to record the latest river stage and predicted flood-crest information along the Withlacoochee River, Little River, and Okapilco Creek in south-central Georgia and northern Florida. By comparing the current stage (water-surface level above a datum) and predicted flood crest to the recorded peak stages of previous floods, emergency response personnel and residents can make informed decisions concerning the threat to life and property.

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.

Geochemical Characterization of Late Pleistocene and Holocene Tephra Layers from the Basin of Mexico, Central Mexico

Science.gov (United States)

Ortega-Guerrero, Beatriz; Newton, Anthony J.

1998-07-01

In order to aid palaeoenvironmental research of Late Pleistocene and Holocene deposits of central Mexico, tephra layers collected from the sediments of the Texcoco and Chalco sub-basins, in the southern part of the Basin of Mexico, are geochemically characterized and used as stratigraphic markers. The tephra layers range in composition from basaltic andesites to rhyolites and are calc-alkaline. The tephras range in age from >34,000 to ca. 2600 14C yr B.P. New names are used informally to designate correlated tephras. The Tlahuac tephra is present in Chalco, at a depth of 18 m; in the southeastern part of Texcoco, at a depth of around 10 m; and at the Tlapacoya archaeological site, where it had been mistakenly described as basaltic. This basalt-andesite tephra is dated to at least 34,000 14C yr B.P. The Tlapacoya 1 tephra is dated to between 15,020 ± 450 and 14,430 ± 190 yr B.P. and is present in all Chalco sections. The Tlapacoya 2 tephra corresponds to the previously described "pomez gruesa con fragmentos de andesita" (ca. 14,400 yr B.P.) and is present in all Chalco and Texcoco sections. The likely source of these three tephras is the volcano Popocatepetl. Tephra II at Chalco dates to 12,520 ± 135 yr B.P. and correlates with the Upper Toluca Pumice from Nevado de Toluca volcano. These represent the first geochemical glass-shard analysis of tephras from the Basin of Mexico, and so further research is necessary before a reliable tephrochronology can be established.

Estimating groundwater 14C ages in the arid Ti-Tree Basin, Central Australia: Use of 87Sr/86Sr to constrain sources of inorganic carbon

International Nuclear Information System (INIS)

Harrington, G.A.; Herczeg, A.L.

1999-01-01

The Ti-Tree Basin in the Northern Territory of and Central Australia contains several Tertiary and Quaternary aquifers which yield high-quality groundwater (TDS generally < 1500 mg/l). This resource is vital to the existence of major horticultural developments in the Basin, and provides a reliable supply of water to the township of Ti-Tree (population ∼ 100) and numerous remote Aboriginal communities. To meet increasing demands for water to expand the horticulture industry, it has become necessary to gain a proper understanding of the processes which govern the lifetime of this groundwater resource

The Port Isabel Fold Belt: Salt enhanced Neogene Gravitational Spreading in the East Breaks, Western Gulf of Mexico

Science.gov (United States)

Lebit, Hermann; Clavaud, Marie; Whitehead, Sam; Opdyke, Scott; Luneburg, Catalina

2017-04-01

The Port Isabel fold belt is situated at the northwestern corner of the deep water Gulf of Mexico where the regional E-W trending Texas-Louisiana shelf bends into the NNE-SSW trend of the East Mexico Shelf. The fold belt forms an allochthonous wedge that ramps up from West to East with its front occupied by shallow salt complexes (local canopies). It is assumed that the belt predominantly comprises Oligocene siliciclastic sequences which reveal eastward facing folds and thrusts with a NE-SW regional trend. The structural architecture of the fold belt is very well imaged on recently processed 3D seismic volumes. Crystal III is a wide-azimuth survey acquired in 2011 and reprocessed in 2016 leveraging newly developed state-of-the-art technology. 3D deghosting, directional designature and multi-model 3D SRME resulted in broader frequency spectrum. The new image benefits from unique implementation of FWI, combined with classic tomographic updates. Seismically transparent zones indicating over-pressured shales are limited to the core of anticlines or to the footwall of internal thrust. Mobile shales associated with diapirs are absent in the study area. In contrast, salt is mobile and apparently forms the major decollement of the PIFB as indicated by remnant salt preferentially located in triangles along the major thrusts and fault intersections or at the core of anticlines. Shallow salt diapirs seam to root in the fold belt, while lacking evidence for salt feeders being connected to the deep salt underlying the Mesozoic to Paleogene substratum of the fold belt. Towards the WNW the fold belt is transient into a extensional regime, characterized by roll-over structures associated with deep reaching normal faults which form ultra-deep mini basins filled with Neogene deposits. Kinematic restorations confirm the simultaneous evolution of the deep mini basins and the outboard fold belt. This resembles a gravitational spreading system with the extensional tectonics of the deep

Applying limited data to estimate groundwater recharge in the Bida Basin, central Nigeria

International Nuclear Information System (INIS)

Shekwolo, P. D.

2000-01-01

Three river catchment basins in central Nigeria were studied to determine the amount to recharge to groundwater reservoir, using different techniques. The techniques include groundwater rise or specific yield, flownet, baseflow separation and chloride mass balance (CMB). Though results from the various methods vary within some limits, there is a fairly good agreement, particularly in the recharge percentages. Groundwater rise technique gave a value of about 53 mm/yr and 56 mm/yr in Gboko and Eku catchments respectively, which represents about 5% of the annual precipitation in Eku catchment. CMB method yielded 5% in Gboko, 4% in Eku and 7% in Kaduna catchment of annual precipitation. On the average, annual recharge in the entire basins falls within the range of 50 mm to 100 mm, which constitute about 5 - 10% of annual precipitation. All the methods can be considered complementary to each other, in the sense that sone salient hydrologic parameters that are not considered or emphasised in one technique appear in the other. The chloride mass and baseflow separation methods can be said to be fair result - yielding approach, because of the relatively good data acquisition in spite of the limitations of the method and their relevance to prevailing local conditions. Multi - technique approach is the best in recharge estimation because it allows an independent check to be made on the results. The value of hydrologic ration falls within the range of 0.45 to 0.8 and the study area has been classified into semi - humid and semi - arid climatic zones, on the basis of the hydrologic model

Evolution of the alluvial fans of the Luo River in the Weihe Basin, central China, controlled by faulting and climate change - A reevaluation of the paleogeographical setting of Dali Man site

NARCIS (Netherlands)

Rits, Daniël S.; van Balen, Ronald T.; Prins, Maarten A.; Zheng, Hongbo

2017-01-01

The Luo River is located in the southern part of the Chinese Loess Plateau and the northern part of the Weihe Basin, in Central China. In the basin it flows proximal to the site of the Luyang Wetland core, which is an important archive of climate change over the past 1 Myr in this region. In this

Petrography, fine stratigraphy and petrofacies of the Stassfurt rock salt (Zechstein 2) in the development region of ASSE II salt mine near Brunswick

International Nuclear Information System (INIS)

Diem, W.

1985-01-01

The Stassfurt rock salt (Na2) in the Asse II salt mine constitutes a saline sequence of the sub-Hercynian basin. In the anticline of the Asse II the Na2 constitutes a core of the anticline with an interior special folding. The combination of underground mapping with the investigations of the salt petrography permits the recognition of stratigraphic unities and with it sedimentary and early diagenetic formation processes for the stratigraphic beds of the Hauptsalz (Na2β), the Speisesalz (Na2SP) and the Polyhalitbaenkchensalz (Na2P). An additional postdiagenetic new formation of minerals from the overlying Stassfurt potash layer (K2C) can be recognized in the kieseritic region of the ''Carnallitisch-Kieseritische Ueberganssalz (Na2K+C)'' and in the ''Tonliniensalz'' (Na2TL). The lower part of the Na2β belongs to a saline basin facies. In the upper part of the Na2β structural and textural characteristics refer to the swallowing of the saline sedimentation room. Simultaneously, more and more terrestrial influences of the saline sedimentation become conspicuous in the northwestern part of the Asse II. They have their clearest facies in the only locally formed Tonliniensalz (Na2TL). The petrographic review of the ''polyhalite region'', which encloses the upper part of the Na2β, the Na2SP and the Na2P, rendered obvious indications for a pseudomorphic origin of polyhalite from primarily sedimened gypsum. The replacement of anhydrite by polyhalite was compared to it as being of unimportant significance. The quantitative parts of the accessory minerals (polyhalite, anhydrite, kieserite, sylvite, carnallite) were determined by means of geochemical investigations in the stratigraphic horizons of Na2 in the mine Asse II. A regional comparison with the saline sedimentation of Zechstein 2 in the sub-Hercynian basin shows a progressive saline sedimentation cycle of the Stassfurt type for the fine stratigraphic division of the Na2 in Asse II. (orig./HP) [de

Palaeogeographic evolution of the marine Middle Triassic marine Germanic Basin changements - With emphasis on the carbonate tidal flat and shallow marine habitats of reptiles in Central Pangaea

Science.gov (United States)

Diedrich, Cajus G.

2009-01-01

More than seventy-five vertebrate track-sites have been found in Central Europe in 243-246.5 m.y. old Triassic coastal intertidal to sabkha carbonates. In the western part of the very flat Triassic intracontinental Germanic Basin, the carbonate strata contain at least 22 laterally extensive track horizons (called megatracksites). In contrast, in the eastern part of the basin only six megatracksites extended to near the centre of the Basin during marine low stands. Marine ingression and the development of extensive coastal marine environments began during the Aegean (Anisian) stage. This incursion began in the region of the eastern Carpathian and Silesian gates and spread westward due to the development of a tectonically controlled intracratonic basin. The tectonic origin of this basin made it susceptible to tsunamis and submarine earthquakes, which constituted very dangerous hazards for coastal terrestrial and even marine reptiles. The shallow sea that spread across the Germanic Basin produced extensive tidal flats that at times formed extensive inter-peninsular bridges between the Rhenish and Bohemian Massifs. The presence of these inter-peninsular bridges explains the observed distribution and movement of reptiles along coastal Europe and the northern Tethys Seaway during the Middle Triassic epoch. Two small reptiles, probably Macrocnemus and Hescherleria, left millions of tracks and trackways known as Rhynchosauroides and Procolophonichnium in the Middle Triassic coastal intertidal zone. The great abundance of their tracks indicates that their trackmakers Macrocnemus and Hescherleria were permanent inhabitants of this environment. In sharp contrast, tracks of other large terrestrial reptiles are quite rare along the coastal margins of the Germanic Basin, for example the recently discovered archaeosaur tracks and trackways referable to Isochirotherium, which most probably were made by the carnivore Ticinosuchus. Smaller medium-sized predatory thecodont reptiles

New sedimentological and palynological data from surface Miocene strata in the central Amazonas Basin area

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Emílio Alberto Amaral Soares

Full Text Available ABSTRACT The scarcity of stratigraphic data has hindered the demarcation of the outcropping area of Miocene deposits of the Amazon Basin, represented informally by the Novo Remanso Formation. Moreover, this unit is characterized by a sparse and irregular geographic distribution due to its sedimentological features and rare fossil content. Miocene deposits cropping out in central Amazonas Basin area were described in sedimentological terms and analyzed palynologically. All analyses were undertaken in samples collected at the Uatumã River banks (Itapiranga and São Sebastião do Uatumã cities. Lithostratigraphic data shows that Novo Remanso Formation consists of sandstones, with subordinate conglomerates and pelites, characteristic of a meandering fluvial paleosystem, with fluvial channel, point bar, floodplain and crevasse splay facies. The palynoflora retrieved from five samples consists exclusively of continental-origin palynomorphs dominated by angiosperms species. Trilete spores are well represented, while gymnosperms pollen grains are minor components. The presence of Psilastephanoporites tesseroporus, Syncolporites poricostatus, Jandufouria seamrogiformis and Polypodiaceoisporites potoniei ensure these deposits fits into the Grimsdalea magnaclavata palynozone (Regali et al. 1974a, b, and the Grimsdalea magnaclavata/Crassoretitriletes vanraadshooveni palynozones of Jaramillo et al. (2011 considered Middle Miocene age. This age is confirmed by the zonation of Jaramillo et al. (2011, based on the LADs of Bombacacidites baumfalki (11.57Ma and Crototricolpites annemariae (12.91Ma; and the FAD of Psilastephanoporites tesseroporus (14.00Ma. With these new data presented herein, it is possible to assume that the Miocene strata represented by the Novo Remanso Formation covers a larger area in the basin than previously considered, and that it may be extended for about 300 km until the Manacapuru village, indicating a Miocene subsidence phase.

Wellbore stability analysis and its application in the Fergana basin, central Asia

Science.gov (United States)

Chuanliang, Yan; Jingen, Deng; Baohua, Yu; Hailong, Liu; Fucheng, Deng; Zijian, Chen; Lianbo, Hu; Haiyan, Zhu; Qin, Han

2014-02-01

Wellbore instability is one of the major problems hampering the drilling speed in the Fergana basin. Comprehensive analysis of the geological and engineering data in this area indicates that the Fergana basin is characterized by high in situ stress and plenty of natural fractures, especially in the formations which are rich in bedding structure and have several high-pressure systems. Complex accidents such as wellbore collapse, sticking, well kick and lost circulation happen frequently. Tests and theoretical analysis reveals that the wellbore instability in the Fergana basin was influenced by multiple interactive mechanisms dominated by the instability of the bedding shale. Selecting a proper drilling fluid density and improving the sealing characteristic of the applied drilling fluid is the key to preventing wellbore instability in the Fergana basin. The mechanical mechanism of wellbore instability in the Fergana basin was analysed and a method to determine the proper drilling fluid density was proposed. The research results were successfully used to guide the drilling work of the Jida-4 well; compared with the Jida-3 well, the drilling cycle of the Jida-4 well was reduced by 32%.

Optimum level of salt in French-type bread. Influence of income status, salt level in daily bread consumption, and test location.

Science.gov (United States)

Sosa, M; Flores, A; Hough, G; Apro, N; Ferreyra, V; Orbea, M M

2008-10-01

The objectives of the present study were to measure the ideal salt concentration in French-type bread among Argentine consumers in a home-usage-test (HUT) considering income status and salt content of daily bread consumption as covariables, and to compare the ideal salt concentrations measured in a HUT and a central-location test (CLT). For the HUT, 420 consumers each received a sample of bread with a single salt concentration, and for the CLT, 100 consumers each received 7 samples with different salt concentrations. For each sample, consumers responded if they found the bread "not-salty-enough,"okay," or "too-salty." Neither income level nor salt content of daily bread influenced probability of rejection. The optimum sodium concentrations (milligrams per 100 g of bread dry basis) +/- 95% confidence limits for the HUT and CLT were 980 +/- 74 and 1157 +/- 87, respectively. These values are substantially higher than 628, the mean sodium content of the bread sampled from the bakery shops where consumers bought their daily bread.

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.

Tree-ring reconstruction of the level of Great Salt Lake, USA

Science.gov (United States)

R. Justin DeRose; Shih-Yu Wang; Brendan M. Buckley; Matthew F. Bekker

2014-01-01

Utah's Great Salt Lake (GSL) is a closed-basin remnant of the larger Pleistocene-age Lake Bonneville. The modern instrumental record of the GSL-level (i.e. elevation) change is strongly modulated by Pacific Ocean coupled ocean/atmospheric oscillations at low frequency, and therefore reflects the decadalscale wet/dry cycles that characterize the region. A within-...

Geochemical and visual indicators of hydrothermal fluid flow through a sediment-hosted volcanic ridge in the Central Bransfield Basin (Antarctica.

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Alfred Aquilina

Full Text Available In the austral summer of 2011 we undertook an investigation of three volcanic highs in the Central Bransfield Basin, Antarctica, in search of hydrothermal activity and associated fauna to assess changes since previous surveys and to evaluate the extent of hydrothermalism in this basin. At Hook Ridge, a submarine volcanic edifice at the eastern end of the basin, anomalies in water column redox potential (E(h were detected close to the seafloor, unaccompanied by temperature or turbidity anomalies, indicating low-temperature hydrothermal discharge. Seepage was manifested as shimmering water emanating from the sediment and from mineralised structures on the seafloor; recognisable vent endemic fauna were not observed. Pore fluids extracted from Hook Ridge sediment were depleted in chloride, sulfate and magnesium by up to 8% relative to seawater, enriched in lithium, boron and calcium, and had a distinct strontium isotope composition ((87Sr/(86Sr = 0.708776 at core base compared with modern seawater ((87Sr/(86Sr ≈ 0.70918, indicating advection of hydrothermal fluid through sediment at this site. Biogeochemical zonation of redox active species implies significant moderation of the hydrothermal fluid with in situ diagenetic processes. At Middle Sister, the central ridge of the Three Sisters complex located about 100 km southwest of Hook Ridge, small water column E(h anomalies were detected but visual observations of the seafloor and pore fluid profiles provided no evidence of active hydrothermal circulation. At The Axe, located about 50 km southwest of Three Sisters, no water column anomalies in E(h, temperature or turbidity were detected. These observations demonstrate that the temperature anomalies observed in previous surveys are episodic features, and suggest that hydrothermal circulation in the Bransfield Strait is ephemeral in nature and therefore may not support vent biota.

Structure of the Anayet Permian basin (Axial Zone, Central Pyrenees)

Science.gov (United States)

Rodriguez, L.; Cuevas, J.; Tubía, J. M.

2012-04-01

The Anayet Permian basin was generated by strike-slip tectonics that opened subsident basins with pull-apart geometries in the western Spanish Axial Zone (between the Aragon and Tena valleys). A continental succession of Permian age, that represents the first post-variscan deposits in the area, fills the basin and covers discordantly Devonian to Carboniferous limestones, sandstones and slates. Permian deposits have been classically divided in four main detrital groups, with three basic volcanic episodes interbedded (Gisbert, 1984, Bixel, 1987): the Grey Unit (50-120 m, Estefanian to Kungurian) with slates, conglomerates, tobaceous slates, coal and pyroclastic deposits, the Transition Unit (50 m maximum) showing grey and red sandstones and lutites with oolitic limestones intercalated, the Lower Red Unit (250 m) composed of cross-bedded red sandstones and andesitic volcanic rocks at the top, and finally the Upper Red Unit (400 m minimum, top eroded) formed by three fining up megasequences of carbonates, red sandstones and lutites with lacustrine carbonates intercalated and alkali basalts at the top. Increasingly older rocks are found towards the western part of the basin, where its depocenter is located. South-vergent angular folds deform the Permian sedimentary succession. Fold axes are N115 °E-trending, almost horizontal and are characterized by a remarkably constant orientation. Folds exhibit a long limb dipping slightly to the north and a short vertical limb, occasionally reversed. In the Anayet basin four main folds, with a wavelength of 400 m, can be distinguished, two anticlines and two synclines, with minor folds associated. Related to the angular folds an axial plane foliation, E-trending and dipping 40 to 60° to the north, is developed in the lutites. The more competent rocks, conglomerates and breccias, only locally show a spaced fracture cleavage. No main thrusts have been detected in Permian rocks. However, minor scale decollements, usually low angle

Variability and distribution of COL1A2 (type I collagen) polymorphisms in the central-eastern Mediterranean Basin.

Science.gov (United States)

Scorrano, Gabriele; Lelli, Roberta; Martínez-Labarga, Cristina; Scano, Giuseppina; Contini, Irene; Hafez, Hani S; Rudan, Pavao; Rickards, Olga

2016-01-01

The most abundant of the collagen protein family, type I collagen is encoded by the COL1A2 gene. The COL1A2 restriction fragment length polymorphisms (RFLPs) EcoRI, RsaI and MspI in samples from several different central-eastern Mediterranean populations were analysed and found to be potentially informative anthropogenetic markers. The objective was to define the genetic variability of COL1A2 in the central-eastern Mediterranean and to shed light on its genetic distribution in human groups over a wide geographic area. PCR-RFLP analysis of EcoRI, RsaI and MspI polymorphisms of the COL1A2 gene was performed on oral swab and blood samples from 308 individuals from the central-eastern Mediterranean Basin. The genetic similarities among these groups and other populations described in the literature were investigated through correspondence analysis. Single-marker data and haplotype frequencies seemed to suggest a genetic homogeneity within the European populations, whereas a certain degree of differentiation was noted for the Egyptians and the Turks. The genetic variability in the central-eastern Mediterranean area is probably a result of the geographical barrier of the Mediterranean Sea, which separated European and African populations over time.

The tritium balance of the Ems river basin

International Nuclear Information System (INIS)

Krause, W.J.

1989-01-01

For the Ems river basin, as a fine example of a Central European lowland basin, an inventory of the tritium distribution is presented for the hydrologic years 1951 to 1983. On the basis of a balance model, the tritium contents in surface waters and groundwater of the Ems river basin are calculated, using known and extrapolated tritium input data and comparing them with the corresponding values measured since 1974. A survey of tritium flows occurring in this basin is presented, taking meteorologic and hydrologic facts into account. (orig.)

Developing a Science-based River Basin Management Plan for the Kharaa River Basin, Mongolia

Science.gov (United States)

Karthe, Daniel

2013-04-01

The Kharaa River Basin (KRB), which is located north of Mongolia's capital Ulaanbaatar and south of Lake Baikal, was chosen as a model region for the development and implementation of an integrated water resources management consisting of a monitoring concept, technical measures and a capacity development program (Karthe et al. 2012a). The basin of the Kharaa River covers an area of 14534 km² that is partly mountaineous and largely covered by taiga and steppe. At its outlet, the 362 km Kharaa River has a mean long-term annual discharge of 12.1 m³/s (MoMo Consortium 2009). A highly continental climate results in limited water resources, and rising water consumption coupled with the effects of climate and land use change may in the future exacerbate this water scarcity (Malsy et al. 2012; Karthe et al. 2013). Whereas the environment in the upper part of the catchment is in a relatively pristine state, the mid- and downstream sections of the river are characterized by nearby industry, mining activities and intensive agriculture (Menzel et al. 2011), resulting in declining water quality and ultimately a degradation of aquatic ecosystems (Hofmann et al. 2010; Hartwig et al. 2012). Moreover, it is a problem for the supply of major cities like Darkhan which largely rely on alluvial aquifers containing shallow-depth groundwater (Mun et al. 2008). Currently, there are alarming signs of water quality deterioration. With regard to water provision, a major problem is the poor state of distribution infrastructures which were often built in the 1960s and 70s (Scharaw & Westerhoff 2011). Rather little is currently known about the water quality supplied to end users; the latter is even more dubious in the city's informal ger districts (Karthe et al. 2012b). One important goal of the research and development project "Integrated Water Resources Management in Central Asia: Model Region Mongolia" lies in the implementation of a holistic concept for water resources monitoring and

Structure of an inverted basin from subsurface and field data: the Late Jurassic-Early Cretaceous Maestrat Basin (Iberian Chain)

Energy Technology Data Exchange (ETDEWEB)

Nebot, M.; Guimera, J.

2016-07-01

The Maestrat Basin experienced two main rifting events: Late Permian-Late Triassic and Late Jurassic-Early Cretaceous, and was inverted during the Cenozoic Alpine orogeny. During the inversion, an E-W-trending, N-verging fold-and-thrust belt developed along its northern margin, detached in the Triassic evaporites, while southwards it also involved the Variscan basement. A structural study of the transition between these two areas is presented, using 2D seismic profiles, exploration wells and field data, to characterize its evolution during the Mesozoic extension and the Cenozoic contraction. The S-dipping Maestrat basement thrust traverses the Maestrat Basin from E to W; it is the result of the Cenozoic inversion of the lower segment–within the acoustic basement–of the Mesozoic extensional fault system that generated the Salzedella sub-basin. The syn-rift Lower Cretaceous rocks filling the Salzedella sub-basin thicken progressively northwards, from 350m to 1100m. During the inversion, a wide uplifted area –40km wide in the N-S direction– developed in the hanging wall of the Maestrat basement thrust. This uplifted area is limited to the North by the E-W-trending Calders monocline, whose limb is about 13km wide in its central part, dips about 5ºN, and generates a vertical tectonic step of 800-1200m. We interpreted the Calders monocline as a fault-bend fold; therefore, a flat-ramp-flat geometry is assumed in depth for the Maestrat basement thrust. The northern synformal hinge of the Calders monocline coincides with the transition from thick-skinned to thin-skinned areas. The vast uplifted area and the low-dip of the monocline suggest a very low-dip for the basement ramp, rooted in the upper crust. The Calders monocline narrows and disappears laterally, in coincidence with the outcrop of the Maestrat basement thrust. The evaporitic Middle Muschelkalk detachment conditioned the structural style. Salt structures are also related to it; they developed during the

Drilling in salt formations; Perfuracao em formacoes salinas

Energy Technology Data Exchange (ETDEWEB)

Falcao, Jose Luiz [PETROBRAS, Rio de Janeiro, RJ (Brazil). E e P Engenharia de Producao. Gerencia de Perfuracao e Operacoes Especiais], e-mail: jfalcao@petrobras.com.br; Poiate Junior, Edgard [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas da Petrobras (CENPES). Gerencia de Metodos Cientificos], e-mail: poiate@petrobras.com.br; Costa, Alvaro Maia da [PETROBRAS, Rio de Janeiro, RJ (Brazil). Diretoria de Exploracao e Producao], e-mail: amcta@petrobras.com.br; Alves, Ivan Antonio Silva [PETROBRAS, Rio de Janeiro, RJ (Brazil). E e P Exploracao. Gerencia de Operacoes em Pocos], e-mail: ialves@petrobras.com.br; Eston, Sergio Medici de [Universidade de Sao Paulo (USP), SP (Brazil). Engenharia de Minas e Petroleo], e-mail: e-mail: sergio.eston@poli.usp.br

2007-12-15

This paper is a collection of experiences of service companies, operators and PETROBRAS in the drilling of salt rocks in petroleum prospecting. From the exploratory point of view, the presence of these rocks in the area increases the chances of success. By their characteristics, these sediments can deform, dissolve and migrate, creating preferential flow paths and generating stratigraphic structures and traps ideal for the accumulation of hydrocarbons. This has been a well known fact since the beginning of the petroleum industry. In addition to these factors, the salts are almost perfect seals for the accumulations under them. Their presence in sedimentary basins have an important economical significance, not only in the exploratory interpretation phase, but also in the drilling of wells, as they present mechanical characteristics distinct from siliclastic and carbonatic rocks. However, from the operational point of view, the drilling of some of these salt rocks is associated with a large number of well stability problems (in the short term) and the integrity of wellbore liners (in the long term), when compared to other lithologies. (author)

From the central Jura mountains to the molasse basin (France and Switzerland)

International Nuclear Information System (INIS)

Sommaruga, A.

2011-01-01

This illustrated article discusses the geology of the area covering the Swiss Jura chain of mountains and the molasse basin which is to be found to the south-east of the mountain chain. The geological setting with the Jura Mountains and the molasse basin are described, as are the rocks to be found there. Their structures and faults are discussed in detail and their origin and formation are described. The paper presents a number of geological profiles and maps. The methods used to explore these structures are noted, which also indicated the presence of permo-carboniferous troughs in the molasse basin

From the central Jura mountains to the molasse basin (France and Switzerland)

Energy Technology Data Exchange (ETDEWEB)

Sommaruga, A. [Institut de Géophysique, University of Lausanne, Bâtiment Amphipôle, Lausanne (Switzerland)

2011-07-01

This illustrated article discusses the geology of the area covering the Swiss Jura chain of mountains and the molasse basin which is to be found to the south-east of the mountain chain. The geological setting with the Jura Mountains and the molasse basin are described, as are the rocks to be found there. Their structures and faults are discussed in detail and their origin and formation are described. The paper presents a number of geological profiles and maps. The methods used to explore these structures are noted, which also indicated the presence of permo-carboniferous troughs in the molasse basin.

The development of the Middle Triassic tectonical controlled Germanic Basin of Central Europe and the palaeoenvironmental related distribution of marine and terrestrial reptiles

Science.gov (United States)

Diedrich, Cajus G.

2010-05-01

Nine Middle Triassic paleogeographical maps comprising the uppermost Upper Bunter, Lower to Middle Muschelkalk and Upper Muschelkalk to Lower Keuper time frame (Diedrich 2008b) show the marine ingression and regression cycle of the Middle Triassic Germanic Basin (Diedrich 2010c). For bathymetrical and palaeoenvironmental interpretations especially reptiles and their footprints are used. This Germanic Basin as analogon for the Arabian Gulf (Knaust 1997), north of the Tethys, was under marine and finally terrestrial influenced sediments in a time frame (after Kozur and Bachmann 2008) between 247.2 My (Myophoria Fm, Aegean, Lower Anisian) to 237.9 My (Grabfeld Fm, Longobardian, Lower Ladinian). In a duration of 9.3 My the Germanic Basin was filled up mainly with marine carbonates and at the end by siliciclastics influenced by the northern Tethys through the Silesian, Carpathian and later the Burgundian Gates which connected the Germanic Basin to the Northern Tethys. With the marine ingression from the East via the Silesian Gate (Poland) a ten to hundred kilometers extended intertidal flat to sabkha facies belt surrounded first only the central and then the Western Germanic Basin (Winterswijk, Netherlands). Those intertidal zones were used mainly by two different small reptiles as their primary habitat. Hereby they left Millions of the small tom medium sized footprints of the ichnogenera Rhynchosauroides and Procolophonichnium (Diedrich 2005, 2008a). Larger terrestrial and beach and sabkha adapted reptiles were Tanystrophaeus antiquus and unknown archosaurs, which are recorded only by their footprints. At the beginning of the ingression at the uppermost Bunter a shallow marine invertebrate fauna and coastal reptiles appeared in the Germanic Basin which must have originated mainly from the Northern Tethys. Especially all marine reptiles immigrated from the Tethys which is proven not only by assamblaged Tethyan cephalopod Ceratite species (cf. Diedrich 2008a). The