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Sample records for williston basin carbonates

  1. Improved recovery demonstration for Williston basin carbonates. Annual report, June 10, 1994--June 9, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Sippel, M.; Zinke, S.; Magruder, G.; Eby, D.

    1995-09-01

    The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil in place will result in additional oil recovery by primary and enhanced recovery processes.

  2. Contrasts between Ordovician and Mississippian carbonate depositional styles in Williston basin

    Energy Technology Data Exchange (ETDEWEB)

    Lineback, J.A.; Roth, M.S.; Davidson, M.L.

    1984-04-01

    The Madison Group is an example of a deep-water sediment-starved basin that was filled in by turbidites derived from a ringing carbonate shelf. As the basin filled, the Madison was capped by a basinward prograding sabkha sequence. Correlation of log markers demonstrates considerable bottom topography along prograding clinoform ramps in the lower Madison and the irregularity of the advancing evaporite complex in the upper Madison. Many market horizons pinch out against the clinoform slopes or the prograding evaporites, leaving few regionally traceable markers below the Polar interval. The Madison has a high potential for multiple reservoir development and for multiple stratigraphic traps where pinch-outs and lateral gradations occur. In contrast, log markers in the Bighorn Group extend regionally. The lithologies represented by the markers are also consistent regionally. Several discrete, nonlaterally intergrading events in the upper Bighorn are marked by sharp transitions upward from burrowed, mud-rich carbonate through laminated dolomudstone to anhydrite. The regional persistence of lithofacies, their relatively uniform thickness, and the long distance correlation of log markers indicates both long and short term depositional stability over nearly uniform bottom topography. Deposition took place in a very shallow sea that graded to a carbonate marsh or swamp environment over the entire Williston basin region. Reservoirs are developed at consistent stratigraphic horizons, and the possibility of stratigraphic traps is limited under these conditions.

  3. Using a novel Mg isotope tracer to investigate the dolomitization of the Red River Formation in the Williston Basin

    Science.gov (United States)

    Kimmig, S. R.; Holmden, C. E.; Qing, H.

    2015-12-01

    The Williston Basin is a sub-circular intracratonic basin spanning central North America with its center in NW North Dakota. The Late Ordovician Red River Formation is an economically viable unit in the Williston Basin containing large hydrocarbon reserves in Saskatchewan, North Dakota, Manitoba, and Montana. Red River dolomitization contributed to the reservoir-quality porosity and permeability observed today with three types of dolomite (burrow, matrix, and saddle) possibly representing three events. Dolomitization is widely believed to have resulted from downward percolating brines, due to the stratigraphically close association between dolomite deposits and overlying basin-scale evaporites. However, in contrast, Sr isotope evidence suggests an upward fluid migration in the basin. Spatial variation of Mg isotopes (δ26Mg) may serve as a direct tracer of dolomitizing fluid flow. Dolomite sequesters light isotopes of Mg from dolomitizing fluids, therefore, the fluid will evolve with time and distance to heavier δ26Mg values. Accordingly, the δ26Mg values of the Red River dolomite should increase in the direction of fluid flow. We test this hypothesis on Red River burrow dolomite from the Williston Basin; the first event most often attributed to downward infiltration of brines. Burrow δ26Mg values range between -1.89‰ and -1.31‰. Using contouring software, the data are shown to form a pattern of increasing δ26Mg values out from the center of the Williston Basin, indicating an up-dip migration of dolomitizing fluids through the burrow network, rather than down-dip as suggested by the brine reflux model. We conclude that dolomitization of the Red River carbonate is not tied to the spatial and temporal history of evaporite deposition in the Williston Basin, but rather to the thermal history of the basin, suggesting dolomitization likely occurred during a late Paleozoic heating event that drove Mg-rich connate waters ponded in the center of the basin upwards

  4. Thickness of the Upper Hell Creek hydrogeologic unit in the Williston structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the thickness, in feet, of the Upper Hell Creek hydrogeologic unit in the Williston structural basin. The data are presented as ASCII text files...

  5. Thickness of the upper Fort Union aquifer in the Williston structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the thickness, in feet, of the upper Fort Union aquifer in the Williston structural basin. The data are presented as ASCII text files that can...

  6. Geomechanics and elastic anisotropy of the Bakken Formation, Williston Basin

    Science.gov (United States)

    Ostadhassan, Mehdi

    Many of the earth's rocks exhibit anisotropic characteristics. Anisotropy is particularly common in many sedimentary rocks, such as shales. Anisotropy is defined as the spatial alignment of mineral grains, layers, fractures and stresses which causes elastic wave velocity and other elastic properties to vary with direction. There are two types of anisotropy: intrinsic and stress-induced. Intrinsic anisotropy is caused by beddings, microstructures or aligned fractures formed during deposition. Stress-induced anisotropy is caused by strain associated with external stresses. Intrinsic anisotropy originates in the absence of external stresses, while stress-induced anisotropy results from tectonic and overburden stresses. The style of earth material alignment causes two simplified, but convenient models of anisotropy: vertically transverse isotropy (VTI), like shale, and horizontally transverse isotropy (HTI), like vertically fractured medium. These models have been used to describe how physical properties of rock vary in a medium. Identifying the anisotropy in a formation is important in reservoir characterization seismic data processing and oil-field development. Deep shales are the most abundant yet least characterized sedimentary rocks in the Williston Basin of North Dakota. They are significant sources of hydrocarbon unconventional resources in this basin. This dissertation aims to fulfill an investigation of anisotropy in this rock type in several different facets through exploiting of field data. I seek to generate key information for better interplay of field in-situ stress and the existing natural fracture systems for the purpose of drilling, well completion, perforating, hydraulic fracturing and defining reservoir properties. In this study advanced sonic logging data has been processed and interpreted to calculate three independent shear moduli. These parameters then will be used to estimate Thomsen (1986) anisotropy parameters, elastic stiffness coefficients

  7. Geologic framework for the national assessment of carbon dioxide storage resources: Williston Basin, Central Montana Basins, and Montana Thrust Belt study areas: Chapter J in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Buursink, Marc L.; Merrill, Matthew D.; Craddock, William H.; Roberts-Ashby, Tina L.; Brennan, Sean T.; Blondes, Madalyn S.; Freeman, P.A.; Cahan, Steven M.; DeVera, Christina A.; Lohr, Celeste D.; Warwick, Peter D.; Corum, Margo D.

    2014-01-01

    The 2007 Energy Independence and Security Act directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used by the USGS for the national CO2 assessment follows that of previous USGS work. This methodology is non-economic and is intended to be used at regional to sub-basinal scales.

  8. Potential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota

    Science.gov (United States)

    Post van der Burg, Max; Vining, Kevin C.; Frankforter, Jill D.

    2017-09-28

    The Williston Basin, which includes parts of Montana, North Dakota, and South Dakota in the United States, has been a leading domestic oil and gas producing area. To better understand the potential effects of energy development on environmental resources in the Williston Basin, the U.S. Geological Survey, in cooperation with the Bureau of Land Management, and in support of the needs identified by the Bakken Federal Executive Group (consisting of representatives from 13 Federal agencies and Tribal groups), began work to synthesize existing information on science topics to support management decisions related to energy development. This report is divided into four chapters (A–D). Chapter A provides an executive summary of the report and principal findings from chapters B–D. Chapter B provides a brief compilation of information regarding the history of energy development, physiography, climate, land use, demographics, and related studies in the Williston Basin. Chapter C synthesizes current information about water resources, identifies potential effects from energy development, and summarizes water resources research and information needs in the Williston Basin. Chapter D summarizes information about ecosystems, species of conservation concern, and potential effects to those species from energy development in the Williston Basin.

  9. Brine contamination to aquatic resources from oil and gas development in the Williston Basin, United States

    Science.gov (United States)

    Gleason, Robert A.; Contributions by Chesley-Preston, Tara L.; Coleman, James L.; Haines, Seth S.; Jenni, Karen E.; Nieman, Timothy L.; Peterman, Zell E.; van der Burg, Max Post; Preston, Todd M.; Smith, Bruce D.; Tangen, Brian A.; Thamke, Joanna N.; Gleason, Robert A.; Tangen, Brian A.

    2014-01-01

    The Williston Basin, which includes parts of Montana, North Dakota, and South Dakota in the United States and the provinces of Manitoba and Saskatchewan in Canada, has been a leading domestic oil and gas producing region for more than one-half a century. Currently, there are renewed efforts to develop oil and gas resources from deep geologic formations, spurred by advances in recovery technologies and economic incentives associated with the price of oil. Domestic oil and gas production has many economic benefits and provides a means for the United States to fulfill a part of domestic energy demands; however, environmental hazards can be associated with this type of energy production in the Williston Basin, particularly to aquatic resources (surface water and shallow groundwater) by extremely saline water, or brine, which is produced with oil and gas. The primary source of concern is the migration of brine from buried reserve pits that were used to store produced water during recovery operations; however, there also are considerable risks of brine release from pipeline failures, poor infrastructure construction, and flow-back water from hydraulic fracturing associated with modern oilfield operations. During 2008, a multidisciplinary (biology, geology, water) team of U.S. Geological Survey researchers was assembled to investigate potential energy production effects in the Williston Basin. Researchers from the U.S. Geological Survey participated in field tours and met with representatives from county, State, tribal, and Federal agencies to identify information needs and focus research objectives. Common questions from agency personnel, especially those from the U.S. Fish and Wildlife Service, were “are the brine plumes (plumes of brine-contaminated groundwater) from abandoned oil wells affecting wetlands on Waterfowl Production Areas and National Wildlife Refuges?” and “are newer wells related to Bakken and Three Forks development different than the older

  10. Hydrogeologic framework of the uppermost principal aquifer systems in the Williston and Powder River structural basins, United States and Canada

    Science.gov (United States)

    Thamke, Joanna N.; LeCain, Gary D.; Ryter, Derek W.; Sando, Roy; Long, Andrew J.

    2014-01-01

    The glacial, lower Tertiary, and Upper Cretaceous aquifer systems in the Williston and Powder River structural basins within the United States and Canada are the uppermost principal aquifer systems and most accessible sources of groundwater for these energy-producing basins. The glacial aquifer system covers the northeastern part of the Williston structural basin. The lower Tertiary and Upper Cretaceous aquifer systems are present in about 91,300 square miles (mi2) of the Williston structural basin and about 25,500 mi2 of the Powder River structural basin. Directly under these aquifer systems are 800 to more than 3,000 feet (ft) of relatively impermeable marine shale that serves as a basal confining unit. The aquifer systems in the Williston structural basin have a shallow (less than 2,900 ft deep), wide, and generally symmetrical bowl shape. The aquifer systems in the Powder River structural basin have a very deep (as much as 8,500 ft deep), narrow, and asymmetrical shape.

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

    Science.gov (United States)

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

    2008-12-01

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

  12. Study of the geothermal production potential in the Williston Basin, North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Min H.

    1991-09-10

    Preliminary studies of geothermal production potential for the North Dakota portion of the Williston Basin have been carried out. Reservoir data such as formation depth, subsurface temperatures, and water quality were reviewed for geothermal brine production predictions. This study, in addition, provides important information about net pay thickness, porosity, volume of geothermal water available, and productivity index for future geothermal direct-use development. Preliminary results show that the Inyan Kara Formation of the Dakota Group is the most favorable geothermal resource in terms of water quality and productivity. The Madison, Duperow, and Red River Formations are deeper formations but because of their low permeability and great depth, the potential flow rates from these three formations are considerably less than those of the Inyan Kara Formation. Also, poor water quality and low porosity will make those formations less favorable for geothermal direct-use development.

  13. Assessment of an enhanced geothermal system targeting the Prairie Evaporite Formation of the Williston Basin in SW Manitoba

    Science.gov (United States)

    Holländer, Hartmut; Niloofar, Firoozy

    2017-04-01

    Canada has a large potential for geothermal energy production. High thermal resources are recognized at the volcanic belt within the Canadian Cordillera due to the difference between the oceanic and the continental heat flux which creates a border with high heat flow (as high as 150°C/km) along the volcanic belt. However, also regions with lower heat flow such as the Western Canadian Sedimentary Basin (WCSB) is of interest for geothermal usage. The Williston Basin as part of the WCSB shows low thermal gradients of 25-40°C/km. The geology and lithology of Williston Basin show the presence of halite, potassium salts and carbonate wedges within the Prairie Evaporite formation. Halite is the mineral form (salt) of sodium chloride (NaCl) which decreases thermal resistance providing paths of heat transfer to the surface and has 2-3 times higher thermal conductivity comparing to other types of minerals. The potential of a proposed enhanced geothermal system (EGS) to provide adequate energy to a 10-megawatt electricity production plant was investigated. Borehole data from the Manitoban part of the Williston Basin were collected, and two numerical models were built. One model was created for Tilston, SW Manitoba and the second at a generic site in southern Saskatchewan. Geology differs between the sites in terms of layer thicknesses and their depths. The geological sequence is identical. Both sites contain the Prairie Evaporite which consists mainly of halite. The low thermal resistance of the Prairie Evaporite is assumed to be the driving force behind a relatively high temperature at a low depth, which translates into a lower drilling cost to reach the desired layer. The Prairie Evaporite Formation is located at the Tilston site at a depth of 1.5 km with a reservoir thickness of 118 m, while the similar generic's reservoir is present at a depth of 3 km. The design suggested a two well system having one injection and one pumping well. Saline formations are impermeable and

  14. Altitude of the top of the Upper Hell Creek hydrogeologic unit in the Williston structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the altitude, in feet above North American Vertical Datum of 1988 (NAVD88), of the Upper Hell Creek hydrogeologic unit in the Williston...

  15. Potential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota—Species of conservation concern: Chapter D in Potential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota

    Science.gov (United States)

    Post van der Burg, Max; Symstad, Amy J.; Igl, Lawrence D.; Mushet, David M.; Larson, Diane L.; Sargeant, Glen A.; Harper, David D.; Farag, Aïda M.; Tangen, Brian A.; Anteau, Michael J.

    2017-09-28

    The ecosystems of the Williston Basin provide direct and indirect benefits to society. These benefits include carbon sequestration, flood control, nutrient rich soils for agricultural productivity, and habitat for wildlife. This chapter’s main focus is on the effects of energy development on species that occupy the ecosystems in the Williston Basin. We compiled a list of documented species of conservation concern that are of most interest to Federal regulators and resource managers. Species of concern were either listed as endangered or threatened under the Endangered Species Act or listed by States as species of concern in Natural Heritage Program checklists or State Wildlife Action Plans. All told, we determined that 357 species of concern likely occupy the Williston Basin. These species represented seven different taxonomic groups: plants (native and nonnative), terrestrial invertebrates, birds, mammals, reptiles and amphibians, and fish and mussels.We reviewed the existing scientific information pertaining to potential effects of energy development on these taxonomic groups. Currently, little is known about the abundance and distribution of many of these species. But some information exists that may be useful in predicting the potential effects of energy development on certain taxonomic groups. Most of this information has been developed through scientific research focused on effects to mammal and bird populations. Effects to other taxonomic groups seems to be understudied. In general, it seems that disturbances and modifications associated with development have the potential to negatively affect a wide range of species; however, many studies produce uncertain results because they are not designed to compare populations before and after energy development takes place. Most of these studies also do not monitor resources over multiple years and thus cannot detect population trends. Likewise, there are few examples of landscape-scale assessments of the

  16. Reservoir characterization of the Mississippian Ratcliffe, Richland County, Montana, Williston Basin. Topical report, September 1997

    Energy Technology Data Exchange (ETDEWEB)

    Sippel, M.; Luff, K.D.; Hendricks, M.L.

    1998-07-01

    This topical report is a compilation of characterizations by different disciplines of the Mississippian Ratcliffe in portions of Richland County, MT. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity and methods for improved recovery. The report covers investigations of geology, petrography, reservoir engineering and seismic. The Ratcliffe is a low permeability oil reservoir which appears to be developed across much of the study area and occurs across much of the Williston Basin. The reservoir has not been a primary drilling target in the study area because average reserves have been insufficient to payout the cost of drilling and completion despite the application of hydraulic fracture stimulation. Oil trapping does not appear to be structurally controlled. For the Ratcliffe to be a viable drilling objective, methods need to be developed for (1) targeting better reservoir development and (2) better completions. A geological model is presented for targeting areas with greater potential for commercial reserves in the Ratcliffe. This model can be best utilized with the aid of 3D seismic. A 3D seismic survey was acquired and is used to demonstrate a methodology for targeting the Ratcliffe. Other data obtained during the project include oriented core, special formation-imaging log, pressure transient measurements and oil PVT. Although re-entry horizontal drilling was unsuccessfully tested, this completion technology should improve the economic viability of the Ratcliffe. Reservoir simulation of horizontal completions with productivity of three times that of a vertical well suggested two or three horizontal wells in a 258-ha (640-acre) area could recover sufficient reserves for profitable drilling.

  17. Conceptual model of the uppermost principal aquifer systems in the Williston and Powder River structural basins, United States and Canada

    Science.gov (United States)

    Long, Andrew J.; Aurand, Katherine R.; Bednar, Jennifer M.; Davis, Kyle W.; McKaskey, Jonathan D.R.G.; Thamke, Joanna N.

    2014-01-01

    The three uppermost principal aquifer systems of the Northern Great Plains—the glacial, lower Tertiary, and Upper Cretaceous aquifer systems—are described in this report and provide water for irrigation, mining, public and domestic supply, livestock, and industrial uses. These aquifer systems primarily are present in two nationally important fossil-fuelproducing areas: the Williston and Powder River structural basins in the United States and Canada. The glacial aquifer system is contained within glacial deposits that overlie the lower Tertiary and Upper Cretaceous aquifer systems in the northeastern part of the Williston structural basin. Productive sand and gravel aquifers exist within this aquifer system. The Upper Cretaceous aquifer system is contained within bedrock lithostratigraphic units as deep as 2,850 and 8,500 feet below land surface in the Williston and Powder River structural basins, respectively. Petroleum extraction from much deeper formations, such as the Bakken Formation, is rapidly increasing because of recently improved hydraulic fracturing methods that require large volumes of relatively freshwater from shallow aquifers or surface water. Extraction of coalbed natural gas from within the lower Tertiary aquifer system requires removal of large volumes of groundwater to allow degasification. Recognizing the importance of understanding water resources in these energy-rich basins, the U.S. Geological Survey (USGS) Groundwater Resources Program (http://water.usgs.gov/ogw/gwrp/) began a groundwater study of the Williston and Powder River structural basins in 2011 to quantify this groundwater resource, the results of which are described in this report. The overall objective of this study was to characterize, quantify, and provide an improved conceptual understanding of the three uppermost and principal aquifer systems in energy-resource areas of the Northern Great Plains to assist in groundwater-resource management for multiple uses. The study area

  18. Presence and abundance of non-native plant species associated with recent energy development in the Williston Basin

    Science.gov (United States)

    Preston, Todd M.

    2015-01-01

    The Williston Basin, located in the Northern Great Plains, is experiencing rapid energy development with North Dakota and Montana being the epicenter of current and projected development in the USA. The average single-bore well pad is 5 acres with an estimated 58,485 wells in North Dakota alone. This landscape-level disturbance may provide a pathway for the establishment of non-native plants. To evaluate potential influences of energy development on the presence and abundance of non-native species, vegetation surveys were conducted at 30 oil well sites (14 ten-year-old and 16 five-year-old wells) and 14 control sites in native prairie environments across the Williston Basin. Non-native species richness and cover were recorded in four quadrats, located at equal distances, along four transects for a total of 16 quadrats per site. Non-natives were recorded at all 44 sites and ranged from 5 to 13 species, 7 to 15 species, and 2 to 8 species at the 10-year, 5-year, and control sites, respectively. Respective non-native cover ranged from 1 to 69, 16 to 76, and 2 to 82 %. Total, forb, and graminoid non-native species richness and non-native forb cover were significantly greater at oil well sites compared to control sites. At oil well sites, non-native species richness and forb cover were significantly greater adjacent to the well pads and decreased with distance to values similar to control sites. Finally, non-native species whose presence and/or abundance were significantly greater at oil well sites relative to control sites were identified to aid management efforts.

  19. FIELD IMPLEMENTATION PLAN FOR A WILLISTON BASIN BRINE EXTRACTION AND STORAGE TEST

    Energy Technology Data Exchange (ETDEWEB)

    Hamling, John; Klapperich, Ryan; Stepan, Daniel; Sorensen, James; Pekot, Lawrence; Peck, Wesley; Jacobson, Lonny; Bosshart, Nicholas; Hurley, John; Wilson, William; Kurz, Marc; Burnison, Shaughn; Salako, Olarinre; Musich, Mark; Botnen, Barry; Kalenze, Nicholas; Ayash, Scott; Ge, Jun; Jiang, Tao; Dalkhaa, Chantsalmaa; Oster, Benjamin; Peterson, Kyle; Feole, Ian; Gorecki, Charles; Steadman, Edward

    2016-03-31

    The Energy & Environmental Research Center (EERC) successfully completed all technical work of Phase I, including development of a field implementation plan (FIP) for a brine extraction and storage test (BEST) in the North Dakota portion of the Williston Basin. This implementation plan was commissioned by the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) as a proxy for managing formation pressure plumes and measuring/monitoring the movement of differential pressure and CO2 plumes in the subsurface for future saline CO2 storage projects. BEST comprises the demonstration and validation of active reservoir management (ARM) strategies and extracted brine treatment technologies. Two prospective commercial brine injection sites were evaluated for BEST to satisfy DOE’s goals. Ultimately, an active saltwater disposal (SWD) site, Johnsons Corner, was selected because it possesses an ideal combination of key factors making it uniquely suited to host BEST. This site is located in western North Dakota and operated by Nuverra Environmental Solutions (Nuverra), a national leader in brine handling, treatment, and injection. An integrated management approach was used to incorporate local and regional geologic characterization activities with geologic and simulation models, inform a monitoring, verification, and accounting (MVA) plan, and to conduct a risk assessment. This approach was used to design a FIP for an ARM schema and an extracted brine treatment technology test bed facility. The FIP leverages an existing pressure plume generated by two commercial SWD wells. These wells, in conjunction with a new brine extraction well, will be used to conduct the ARM schema. Results of these tests will be quantified based on their impact on the performance of the existing SWD wells and the surrounding reservoir system. Extracted brine will be injected into an underlying deep saline formation through a new injection well. The locations of proposed

  20. Chemical and isotopic changes in Williston Basin brines during long-term oil production: An example from the Poplar dome, Montana

    Science.gov (United States)

    Peterman, Zell; Thamke, Joanna N.

    2016-01-01

    Brine samples were collected from 30 conventional oil wells producing mostly from the Charles Formation of the Madison Group in the East and Northwest Poplar oil fields on the Fort Peck Indian Reservation, Montana. Dissolved concentrations of major ions, trace metals, Sr isotopes, and stable isotopes (oxygen and hydrogen) were analyzed to compare with a brine contaminant that affected groundwater northeast of the town of Poplar. Two groups of brine compositions, designated group I and group II, are identified on the basis of chemistry and 87Sr/86Sr ratios. The solute chemistry and Sr isotopic composition of group I brines are consistent with long-term residency in Mississippian carbonate rocks, and brines similar to these contaminated the groundwater. Group II brines probably resided in clastic rocks younger than the Mississippian limestones before moving into the Poplar dome to replenish the long-term fluid extraction from the Charles Formation. Collapse of strata at the crest of the Poplar dome resulting from dissolution of Charles salt in the early Paleogene probably developed pathways for the ingress of group II brines from overlying clastic aquifers into the Charles reservoir. Such changes in brine chemistry associated with long-term oil production may be a widespread phenomenon in the Williston Basin.

  1. Diagenesis and fracture development in the Bakken Formation, Williston Basin; implications for reservoir quality in the middle member

    Science.gov (United States)

    Pitman, Janet K.; Price, Leigh C.; LeFever, Julie A.

    2001-01-01

    The middle member of the Bakken Formation is an attractive petroleum exploration target in the deeper part of the Williston Basin because it is favorably positioned with respect to source and seal units. Progressive rates of burial and minor uplift and erosion of this member led to a stable thermal regime and, consequently, minor variations in diagenesis across much of the basin. The simple diagenetic history recorded in sandstones and siltstones in the middle member can, in part, be attributed to the closed, low-permeability nature of the Bakken petroleum system during most of its burial history. Most diagenesis ceased in the middle member when oil entered the sandstones and siltstones in the Late Cretaceous. Most oil in the Bakken Formation resides in open, horizontal fractures in the middle member. Core analysis reveals that sandstones and siltstones associated with thick mature shales typically have a greater density of fractures than sandstones and siltstones associated with thin mature shales. Fractures were caused by superlithostatic pressures that formed in response to increased fluid volumes in the source rocks during hydrocarbon generation

  2. Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota

    Science.gov (United States)

    Cozzarelli, Isabelle M.; Skalak, Katherine; Kent, D.B.; Engle, Mark A.; Benthem, Adam J.; Mumford, Adam; Haase, Karl B.; Farag, Aïda M.; Harper, David; Nagel, S. C.; Iwanowicz, Luke R.; Orem, William H.; Akob, Denise M.; Jaeschke, Jeanne B.; Galloway, Joel M.; Kohler, Matthias; Stoliker, Deborah L.; Jolly, Glenn D.

    2017-01-01

    Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4 M L (million liters) of wastewater (300 g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples were collected in February and June 2015 to identify geochemical signatures of spilled wastewaters as well as biological responses along a 44-km river reach. February water samples had elevated chloride (1030 mg/L) and bromide (7.8 mg/L) downstream from the spill, compared to upstream levels (11 mg/L and Aquatic health effects were observed in June 2015; fish bioassays showed only 2.5% survival at 7.1 km downstream from the spill compared to 89% at the upstream reference site. Additional potential biological impacts were indicated by estrogenic inhibition in downstream waters. Our findings demonstrate that environmental signatures from wastewater spills are persistent and create the potential for long-term environmental health effects.

  3. Assessment of water and proppant quantities associated with petroleum production from the Bakken and Three Forks Formations, Williston Basin Province, Montana and North Dakota, 2016

    Science.gov (United States)

    Haines, Seth S.; Varela, Brian A.; Hawkins, Sarah J.; Gianoutsos, Nicholas J.; Thamke, Joanna N.; Engle, Mark A.; Tennyson, Marilyn E.; Schenk, Christopher J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Kinney, Scott A.; Mercier, Tracey J.; Martinez, Cericia D.

    2017-06-23

    The U.S. Geological Survey (USGS) has completed an assessment of water and proppant requirements and water production associated with the possible future production of undiscovered oil and gas resources in the Three Forks and Bakken Formations (Late Devonian to Early Mississippian) of the Williston Basin Province in Montana and North Dakota. This water and proppant assessment is directly linked to the geology-based assessment of the undiscovered, technically recoverable continuous oil and gas resources that is described in USGS Fact Sheet 2013–3013.

  4. Reservoir characterization of the Ordovician Red River Formation in southwest Williston Basin Bowman County, ND and Harding County, SD

    Energy Technology Data Exchange (ETDEWEB)

    Sippel, M.A.; Luff, K.D.; Hendricks, M.L.; Eby, D.E.

    1998-07-01

    This topical report is a compilation of characterizations by different disciplines of the Red River Formation in the southwest portion of the Williston Basin and the oil reservoirs which it contains in an area which straddles the state line between North Dakota and South Dakota. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity, and methods for improved recovery. The report is divided by discipline into five major sections: (1) geology, (2) petrography-petrophysical, (3) engineering, (4) case studies and (5) geophysical. Interwoven in these sections are results from demonstration wells which were drilled or selected for special testing to evaluate important concepts for field development and enhanced recovery. The Red River study area has been successfully explored with two-dimensional (2D) seismic. Improved reservoir characterization utilizing 3-dimensional (3D) and has been investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Targeted drilling from predictions using 3D seismic for porosity development were successful in developing significant reserves at close distances to old wells. Short-lateral and horizontal drilling technologies were tested for improved completion efficiency. Lateral completions should improve economics for both primary and secondary recovery where low permeability is a problem and higher density drilling is limited by drilling cost. Low water injectivity and widely spaced wells have restricted the application of waterflooding in the past. Water injection tests were performed in both a vertical and a horizontal well. Data from these tests were used to predict long-term injection and oil recovery.

  5. Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota.

    Science.gov (United States)

    Cozzarelli, I M; Skalak, K J; Kent, D B; Engle, M A; Benthem, A; Mumford, A C; Haase, K; Farag, A; Harper, D; Nagel, S C; Iwanowicz, L R; Orem, W H; Akob, D M; Jaeschke, J B; Galloway, J; Kohler, M; Stoliker, D L; Jolly, G D

    2017-02-01

    Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4ML (million liters) of wastewater (300g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples were collected in February and June 2015 to identify geochemical signatures of spilled wastewaters as well as biological responses along a 44-km river reach. February water samples had elevated chloride (1030mg/L) and bromide (7.8mg/L) downstream from the spill, compared to upstream levels (11mg/L and oil were not detected in filtered samples but low levels, including tetramethylbenzenes and di-methylnaphthalenes, were detected in unfiltered water samples downstream from the spill. Labile sediment-bound barium and strontium concentrations (June 2015) were higher downstream from the Spill Site. Radium activities in sediment downstream from the Spill Site were up to 15 times the upstream activities and, combined with Sr isotope ratios, suggest contributions from the pipeline fluid and support the conclusion that elevated concentrations in Blacktail Creek water are from the leaking pipeline. Results from June 2015 demonstrate the persistence of wastewater effects in Blacktail Creek several months after remediation efforts started. Aquatic health effects were observed in June 2015; fish bioassays showed only 2.5% survival at 7.1km downstream from the spill compared to 89% at the upstream reference site. Additional potential biological impacts were indicated by estrogenic inhibition in downstream waters. Our findings demonstrate that environmental signatures from wastewater spills are persistent and create the potential for long-term environmental health effects. Published by Elsevier B.V.

  6. Manitoba Williston Basin activity update

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J. [Manitoba Industry, Trade and Mines, Winnipeg, MB (Canada)

    2003-07-01

    This presentation described the drilling activity in Manitoba from 1998 to 2002 with particular emphasis on horizontal well drilling and production by geologic formation, including the Bakken, Lodgepole and the Lower Amaranth Formations. A total of 97 wells were drilled in Manitoba in 2002. The most active drillers were EOG Resources Canada with a total of 34 wells. Tundra Oil and Gas was close behind with 28 wells, followed by Chevron Canada Resources with 21 wells. Horizontal drilling had a major impact in Manitoba between 1998-2002, representing 30 per cent of drilling activity focused on the Waskada, Virden and Daly fields. Expansion activity throughout the province contributed to the overall increase in oil production for four consecutive years. Annual production reached 650.7 10{sup 3}m{sup 3} in 2001. Manitoba's top 5 producers are Chevron Canada Resources, Tundra Oil and Gas, EOG Resources Canada, Canadian Natural Resources and NCE Petrofund. Together, they account for 89 per cent of Manitoba's production. This paper also described some of the initiatives that Manitoba's Department of Industry, Trade and Mines has taken to improve oil and gas regulations through proposed amendments to the Oil and Gas Act, a review of the Manitoba Drilling Incentive Program, battery re-permitting, and a strategy for managing orphaned wells. 3 figs.

  7. Traces in the dark: sedimentary processes and facies gradients in the upper shale member of the Upper Devonian-Lower Mississippian Bakken Formation, Williston Basin, North Dakota, U.S.A.

    Science.gov (United States)

    Egenhoff, Sven O.; Fishman, Neil S.

    2013-01-01

    Black, organic-rich rocks of the upper shale member of the Upper Devonian–Lower Mississippian Bakken Formation, a world-class petroleum source rock in the Williston Basin of the United States and Canada, contain a diverse suite of mudstone lithofacies that were deposited in distinct facies belts. The succession consists of three discrete facies associations (FAs). These comprise: 1) siliceous mudstones; 2) quartz- and carbonate-bearing, laminated mudstones; and 3) macrofossil-debris-bearing massive mudstones. These FAs were deposited in three facies belts that reflect proximal to distal relationships in this mudstone system. The macrofossil-debris-bearing massive mudstones (FA 3) occur in the proximal facies belt and contain erosion surfaces, some with overlying conodont and phosphate–lithoclast lag deposits, mudstones with abundant millimeter-scale siltstone laminae showing irregular lateral thickness changes, and shell debris. In the medial facies belt, quartz- and carbonate-bearing, laminated mudstones dominate, exhibiting sub-millimeter-thick siltstone layers with variable lateral thicknesses and localized mudstone ripples. In the distal siliceous mudstone facies belt, radiolarites, radiolarian-bearing mudstones, and quartz- and carbonate-bearing, laminated mudstones dominate. Overall, total organic carbon (TOC) contents range between about 3 and 10 wt %, with a general proximal to distal decrease in TOC content. Abundant evidence of bioturbation exists in all FAs, and the lithological and TOC variations are paralleled by changes in burrowing style and trace-fossil abundance. While two horizontal traces and two types of fecal strings are recognized in the proximal facies belt, only a single horizontal trace fossil and one type of fecal string characterize mudstones in the distal facies belt. Radiolarites intercalated into the most distal mudstones are devoid of traces and fecal strings. Bedload transport processes, likely caused by storm-induced turbidity

  8. Carbon regeneration in the Cariaco Basin, Venezuela

    Directory of Open Access Journals (Sweden)

    Arístides Marquez

    Full Text Available Abstract The carbon regeneration in the water column of the Cariaco Basin (Venezuela was investigated using a regression model of total alkalinity (TA and the concentration of total inorganic carbon (TCO2. Primary productivity (PP was determined from the inorganic carbon fraction assimilated by phytoplankton and the variation of the 22 and 23ºC isotherm was used as an indicator of coastal upwelling. The results indicate that CO2 levels were lowest (1962 µmol/kg at the surface and increased to 2451 µmol/kg below the oxic-anoxic redox interface. The vertical regeneration distribution of carbon was dominated (82% by organic carbon originating from the soft tissue of photosynthetic organisms, whereas 18% originated from the dissolution of biogenic calcite. The regeneration of organic carbon was highest in the surface layer in agreement with the primary productivity values. However, at the oxic-anoxic interface a second more intense maximum was detected (70-80%, generated by chemotrophic respiration of organic material by microorganisms. The percentages in the anoxic layers were lower than in the oxic zone because aerobic decomposition occurs more rapidly than anaerobic respiration of organic material because more labile fractions of organic carbon have already been mineralized in the upper layers.

  9. Bedrock geologic map of the town of Williston, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital Data from VG07-4, Kim, J., Gale, M., Thompson, P.J. and Derman, K., 2007, Bedrock geologic map of the town of Williston, Vermont: Vermont Geological Survey...

  10. Carbonate Buildups in the Pernambuco Basin, NE Brazil

    Directory of Open Access Journals (Sweden)

    BRUNO V. BUARQUE

    Full Text Available ABSTRACT The Pernambuco Basin represents one of the most prominent regions for deep water oil and gas exploration off the Brazilian coast. This study aims to identify and describe the occurrence of carbonate buildups in the offshore regions of the basin. The study was based on an analysis of a set of 143 2D time-migrated seismic sections that cover the offshore region of the Pernambuco Basin. An interpretation of the seismic dataset was used to define the main seismic sequences related to the main regional pulses of deposition and to identify three main groups of carbonate buildups: 1 shelf margin reefs, 2 patch reefs, and 3 isolated carbonate buildups. The carbonate buildups formed in two main intervals during post-rift sequences of the Santonian-Maastrichtian and Paleocene-Middle Miocene, which extend the known periods of carbonate deposit formation in the basin. The formation of carbonate buildups was controlled by the tectonic evolution of the Pernambuco Plateau, which created a series of paleotopographic highs that enabled the establishment of oceanographically and climatically favorable conditions for carbonate formation and deposition. These findings are important for understanding the evolution of the basin and for future evaluations of its petroleum potential.

  11. Atmospheric carbon burial in modern lake basins and its significance for the global carbon budget

    Science.gov (United States)

    Einsele, Gerhard; Yan, Jianping; Hinderer, Matthias

    2001-10-01

    Lake basins (˜2.7×10 6 km 2, about 0.8% of the ocean surface or 2% of the land surface) bury a surprisingly high amount of atmospheric carbon (˜70×10 6 t/a) which reaches more than one fourth of the annual atmospheric carbon burial in the modern oceans. This is mainly accomplished by the rapid accumulation of lacustrine sediments and a very high preservation factor (on average 50 times higher than that in the oceans). Lakes with relatively large drainage areas commonly display the highest carbon accumulation rates. In most cases, burial of organic matter is more important than that of carbonate carbon produced by silicate weathering, in contrast to the oceans where the burial of atmospheric carbonate carbon almost reaches the same amount as that of organic carbon. Exceptions to this rule are closed lake basins in arid to semiarid climate which precipitate a major part of their atmosphere-derived dissolved inorganic carbon (DIC) as carbonate. These results are demonstrated in some detail for L. Qinghai, China, (low contribution of atmospheric carbonate carbon) and L. Turkana, East Africa, (high contribution from silicate rocks). Further data are gained by estimates for a number of closed and open lakes. The drainage areas of the lakes withdraw atmospheric carbon at rates of mostly 1-4 g/m 2/a, calculated from the lacustrine carbon burial. Carbon burial rates in lakes commonly increase with change to wetter and warmer climate (partially larger lake surfaces, higher rates of seasonal carbonate precipitation, trend to stratified lake waters with oxygen-deficient bottom water). Anthropogenic influence mostly enhances the production and preservation of organic carbon in lake basins (often by a factor of 3-4). After the last glacial maximum, the joint action of the globally spreading vegetation, peat growth, and carbon burial in lakes would have been able to reduce the atmospheric carbon pool to one third to one half of its present amount within a time period of 1 ka

  12. Carbonate platform development in a Paleoproterozoic extensional basin, Vempalle Formation, Cuddapah Basin, India

    Science.gov (United States)

    Chakrabarti, Gopal; Shome, Debasish; Kumar, Subhasish; Stephens, George M.; Kah, Linda C.

    2014-09-01

    Sedimentological investigation of the late Paleoproterozoic (Orosirian) Vempalle Formation of the Cuddapah Basin, Dharwar craton, India, reveals three facies association that range from supratidal to deep subtidal. Sedimentary rocks of this succession are dominated by heterolithic carbonate mudstone, intraformational carbonate conglomerate, and a variety of columnar, domal, and stratiform microbialite facies. Deposition occurred in an extensional regime during development of a low-gradient ramp, where the distribution of microbialite facies is distinctly depth-partitioned. A gradual increase in synoptic relief of columnar stromatolites through the section, and the upward transition from stratiform to columnar microbialites, record a prolonged marine transgression with little or no influx of terrigenous detritus. Siliciclastic influx along the northeastern side of the shelf reflects the redistribution of topographic highs concomitant with large scale volcanic activity. Redistribution of topographic highs eventually led to progradation of peritidal facies and shutting down of the carbonate factory. Earthquake-induced ground shaking and voluminous volcanism experienced by this platform point to the reactivation of a deep-seated mantle-plume that resulted in thermal doming of the Dharwar crust prior to the onset of Cuddapah deposition. Isotopic and elemental chemistry of a selection of Vempalle Formation carbonate rocks record elevated Mn2+ and Fe2+ concentrations and depleted carbon isotope values in inner ramp lagoonal facies, relative to more open marine stromatolitic facies. Patterns of isotopic and elemental variation suggest the presence of geochemically distinct water masses-either within the water column or within substrate pore fluids-that resulted from a combination of globally low marine oxygenation and restricted oceanographic circulation in inner ramp environments. These data suggest that, even in the aftermath of Early Paleoproterozoic oxygenation, that

  13. Carbon isotopic compositions of the Cambrian-Ordovician carbonates in Tarim Basin

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.; He, H.; Shao, L.; Shi, Z.; Gao, Y. [China University of Mining and Technology, Beijing (China). Dept of Resource Exploitation Engineering

    2002-07-01

    Composition features of carbon and oxygen isotopes in marine carbonate rocks of Cambrian-Ordovician in Bachu area of Tarim Basin were researched. Factors influencing the variation of carbon isotope were analysed. The results show that the variation of {delta}{sup 13}C of the Cambrian-Ordovician marine carbonate rocks is closely related to the changes of sea level. The slower organic carbon burial during sea level fall from the Early Cambrian to Middle Cambrian led to a decrease of the {delta}{sup 13}C value of carbonate rocks of this stage. The rise of organic productivity together with a rapid burial of organic carbon during the rise of sea level in Early Ordivician led to an increase of the {delta}{sup 13}C value of carbonate rocks of this stage because of a high sulfate content in seawater in the Middle Cambrian, the reduction by sulfate bacteria caused an oxidation of organic matter, resulting in a decrease of the {delta}{sup 13} values. The negative {delta}{sup 13}C value in some samples may be related to the fractionation of CO{sub 2} emitted from magma activity or volcanism. 14 refs., 2 figs., 2 tabs.

  14. Microbialitic structures in the Sarmatian carbonate deposits from Simleu Basin

    Directory of Open Access Journals (Sweden)

    Hyam Daoud

    2006-04-01

    Full Text Available The Sarmatian deposits from the Şimleu basin are developed in two facies: terrigenous and calcareous. An attempt to distinguish the main types of Sarmatian limestone microfacies was made by Bucur et al. (1992. The present study provides more detail of the sedimentary facies and fabrics of these limestones, emphasizing the essential contribution of microbialites to their formation. The following types of microbialite and microbial structure were found: (1 thrombolites with clotted fabric and fenestral structures; (2 microbial crusts on bioclasts; (3 peloidal microbialites (4 agglutinated microbialites; (5 stromatolites and laminoid-fenestral structures. All these structures played an important role in the accretion of the Sarmatian carbonate deposits in the area studied.

  15. Event sedimentation in low-latitude deep-water carbonate basins, Anegada passage, northeast Caribbean

    Science.gov (United States)

    Chaytor, Jason D.; ten Brink, Uri S.

    2015-01-01

    The Virgin Islands and Whiting basins in the Northeast Caribbean are deep, structurally controlled depocentres partially bound by shallow-water carbonate platforms. Closed basins such as these are thought to document earthquake and hurricane events through the accumulation of event layers such as debris flow and turbidity current deposits and the internal deformation of deposited material. Event layers in the Virgin Islands and Whiting basins are predominantly thin and discontinuous, containing varying amounts of reef- and slope-derived material. Three turbidites/sandy intervals in the upper 2 m of sediment in the eastern Virgin Islands Basin were deposited between ca. 2000 and 13 600 years ago, but do not extend across the basin. In the central and western Virgin Islands Basin, a structureless clay-rich interval is interpreted to be a unifite. Within the Whiting Basin, several discontinuous turbidites and other sand-rich intervals are primarily deposited in base of slope fans. The youngest of these turbidites is ca. 2600 years old. Sediment accumulation in these basins is low (−1) for basin adjacent to carbonate platform, possibly due to limited sediment input during highstand sea-level conditions, sediment trapping and/or cohesive basin walls. We find no evidence of recent sediment transport (turbidites or debris flows) or sediment deformation that can be attributed to the ca. M7.2 1867 Virgin Islands earthquake whose epicentre was located on the north wall of the Virgin Islands Basin or to recent hurricanes that have impacted the region. The lack of significant appreciable pebble or greater size carbonate material in any of the available cores suggests that submarine landslide and basin-wide blocky debris flows have not been a significant mechanism of basin margin modification in the last several thousand years. Thus, basins such as those described here may be poor recorders of past natural hazards, but may provide a long-term record of past oceanographic

  16. Carbon Dioxide Capture and Transportation Options in the Illinois Basin

    Energy Technology Data Exchange (ETDEWEB)

    M. Rostam-Abadi; S. S. Chen; Y. Lu

    2004-09-30

    This report describes carbon dioxide (CO{sub 2}) capture options from large stationary emission sources in the Illinois Basin, primarily focusing on coal-fired utility power plants. The CO{sub 2} emissions data were collected for utility power plants and industrial facilities over most of Illinois, southwestern Indiana, and western Kentucky. Coal-fired power plants are by far the largest CO{sub 2} emission sources in the Illinois Basin. The data revealed that sources within the Illinois Basin emit about 276 million tonnes of CO2 annually from 122 utility power plants and industrial facilities. Industrial facilities include 48 emission sources and contribute about 10% of total emissions. A process analysis study was conducted to review the suitability of various CO{sub 2} capture technologies for large stationary sources. The advantages and disadvantages of each class of technology were investigated. Based on these analyses, a suitable CO{sub 2} capture technology was assigned to each type of emission source in the Illinois Basin. Techno-economic studies were then conducted to evaluate the energy and economic performances of three coal-based power generation plants with CO{sub 2} capture facilities. The three plants considered were (1) pulverized coal (PC) + post combustion chemical absorption (monoethanolamine, or MEA), (2) integrated gasification combined cycle (IGCC) + pre-combustion physical absorption (Selexol), and (3) oxygen-enriched coal combustion plants. A conventional PC power plant without CO2 capture was also investigated as a baseline plant for comparison. Gross capacities of 266, 533, and 1,054 MW were investigated at each power plant. The economic study considered the burning of both Illinois No. 6 coal and Powder River Basin (PRB) coal. The cost estimation included the cost for compressing the CO{sub 2} stream to pipeline pressure. A process simulation software, CHEMCAD, was employed to perform steady-state simulations of power generation systems

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

    OpenAIRE

    Heng Fu; Jianhui Han; Wanbin Meng; Mingshi Feng; Lei Hao; Yanfei Gao; Yueshan Guan

    2017-01-01

    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 d...

  18. Carbonate coatings over plant twigs from the Gyeongsang Basin, Korea

    Science.gov (United States)

    Lee, Seong-Joo; Kong, Dal-Yong; Golubic, Stjepko

    2014-05-01

    The sedimentary sequence of the non-marine Cretaceous Gyeongsang Basin, Korea contains a great number of elongated, rod-like structures, which are characterized by concentric and stromatolitic lamination. The original, branched gross morphology of the ancient plant twigs is often preserved, and remains of plant tissues are well preserved in the central parts of the rod structures that are now filled with siliciclastic sediments following degradation of the original plant materials. They are, therefore, interpreted as stromatolitic algal and/or microbial encrustations over dead or living plant twigs, which formed through concentric carbonate precipitation by epiphytic algal or bacterial photosynthesis. Varied filamentous fossils were found in the organic-rich layers, which are calcified tiny tubes characterized by brown micritic walls and light central parts composed of sparite. Size of filament diameter ranges from 1 to 44 um. Based on size of diameter, absence or presence of branching pattern, and/or their ecological roles in the formation of stromatolites, the filaments were classified into two groups: cyanobacteria (6 um-8 um) and green algae (26 um-29 um). The cyanobacteria must have played a key role in the formation of rod-shaped stromatolites, while green algal filaments were auxiliary stromatolite-builders.

  19. Mississippian carbonate buildups and development of cool-waterlike carbonate platforms in the Illinois Basin, Midcontinent U.S.A.

    Science.gov (United States)

    Lasemi, Z.; Norby, R.D.; Utgaard, J.E.; Ferry, W.R.; Cuffey, R.J.; Dever, G.R.

    2005-01-01

    Numerous biohermal buildups occur in Mississippian (Lower Carboniferous) strata in the Illinois Basin and adjacent regions. They developed as mud mounds, biodetrital calcisiltite mounds, and bryozoan frame thickets (fenestrate-frame coquina or rudstone) during the Kinderhookian and early Meramecian (Tournaisian and early Visean), and as microbial mud mounds, microbial- serpulidbryozoanboundstones, and solenoporoid (red algal) boundstones during the Chesterian (late Visean and Serpukhovian). True Waulsortian mounds did not develop in the Illinois Basin, but echinoderm (primarily crinoids)-bryozoan carbonate banks and bryozoan frame thickets generally occupied the same niche during the Kinderhookian-early Meramecian. Nutrient availability and the resulting increase in the productivity of echinoderms and bryozoans were apparently detrimental to Waulsortian mound development. Deposition of crinoidal-bryozoan carbonates during the Kinderhookian-Osagean initially occurred on a ramp setting that later evolved into a platform with a relatively steep margin through sediment aggradation and progradation. By mid-Osagean-early Meramecian, two such platforms, namely the Burlington Shelf and the Ullin Platform, developed adjacent to a deep, initially starved basin. Sedimentologic and petrographic characteristics of the Kinderhookian-earliest Meramecian carbonates resemble the modern cool-water Heterozoan Association. This is in contrast with post-earliest Meramecian carbonates, which are typically oolitic and peloidal with common peri tidal facies. The post-earliest Meramecian carbonates, therefore, resemble those of the warm-water Photozoan Association. The prevalence of Heterozoan carbonates in the Illinois Basin correlates with a rapid increase in the rate of subsidence and a major second-order eustatic sea-level rise that resulted in deep-water starved basins at this time. In the starved Illinois Basin, deposition was initially limited to a thin phosphatic shale that was

  20. Anthropogenic carbon dioxide in the South Atlantic western basin

    Science.gov (United States)

    Ríos, Aida F.; Vázquez-Rodríguez, Marcos; Padin, X. A.; Pérez, Fiz F.

    2010-10-01

    The meridional WOCE line A17 was conducted during the austral summer of 1994 parallel to the eastern South American coast, from 55°S to 10°S, where one of the main limbs of the North Atlantic Deep Water (NADW), i.e., the southward-flowing Deep Western Boundary Current (DWBC) is found. Full-depth profiles of pH, total alkalinity and total inorganic carbon were measured and checked with analytical CO 2 certified reference materials (CRMs), providing a high-quality dataset with good internal consistency for the CO 2 system parameters that is well suited for anthropogenic CO 2 (C ANT) estimation. For the first time in the western Atlantic basin the C ANT has been calculated using four independent approaches and results are compared. The methods considered are the CFC-based TTD method and the φC T°, TrOCA and ∆C* carbon system-based back-calculation methods. All four methods have produced C ANT distribution patterns that are in general good agreement: maximum concentrations of C ANT (50-60 μmol kg - 1 ) are predicted for the upper warm South Atlantic central waters from the tropical gyres, while the minima (~ 5 μmol kg - 1 ) are located in the old northward-flowing branch of Circumpolar Deep Water. There are, however, some discrepancies detected. The TrOCA method yields the highest overall [C ANT] values, even over the theoretical limit of C ANT saturation for 1994 in the upper layers. The ∆C* approach consistently yielded negative estimates of C ANT below 2800 dbar, even after correcting a reported - 8 μmol kg - 1 bias in the alkalinity measurements of the WOCE A17 line. The main overall difference between the four methods corresponds to the relative C ANT maximum associated with the lower limb of NADW: this structure is well identified in the φC T° and TTD methods but seems to disappear in the case of TrOCA and ∆C*. In agreement with other intercomparison studies of C ANT, the specific inventories are significantly higher (~ 45%) than those reported in

  1. Conventional tree height-diameter relationships significantly overestimate aboveground carbon stocks in the Central Congo Basin

    NARCIS (Netherlands)

    Kearsley, E.; Haulleville, de T.; Hufkens, K.; Kidimbu, A.; Toirambe, B.; Baert, G.; Huygens, D.; Kebede, Y.; Defourny, P.; Bogaert, J.; Beeckman, H.; Steppe, K.; Boeckx, P.; Verbeeck, H.

    2013-01-01

    Policies to reduce emissions from deforestation and forest degradation largely depend on accurate estimates of tropical forest carbon stocks. Here we present the first field-based carbon stock data for the Central Congo Basin in Yangambi, Democratic Republic of Congo. We find an average aboveground

  2. Evaluating the Role of Hydrocarbon Seepage in Carbonate Mound Formation (Offshore Ireland) using Basin Modelling

    Science.gov (United States)

    Naeth, J.; di Primio, R.; Horsfield, B.; Shannon, P.; Bailey, W. R.; Henriet, J. P.

    2003-04-01

    The goal of this project was to assess whether deep water coral mound growth on the continental slope of the north Atlantic could be related to active hydrocarbon leakage. The objects of interest are numerous buried and non-buried carbonate mounds, consisting mainly of corals, carbonate crusts and fine grained clastic sediments in the Porcupine Basin, which is located on the eastern Atlantic continental slope 200 km offshore Ireland and contains the sub-commercial Connemara oil field. To evaluate the possible link between hydrocarbon leakage and mound growth we used 2D and 3D basin modelling in combination with geochemical analysis of sediments from gravity cores. A total of 5 intersecting seismic lines were used as a basis for 2D modelling of basin evolution, hydrocarbon generation and migration. Data from six exploration wells were used for calibration of the basin burial and thermal history using vitrinite reflectance, bottom hole temperatures and apatite fission track data. 3D basin modelling was performed using data provided by UCD in the northern part of the Porcupine Basin. The results of this study indicate that a link between modelled hydrocarbon leakage and carbonate mound growth is possible both in the Belgica mound province on the eastern flank of the basin where stratigraphic pinch outs of carrier beds can lead to the localised leakage of hydrocarbons to the seafloor, as well as in the Hovland Magellan mound area in the northern half of the Porcupine Basin, where small-scale structural closures mapped on the main Miocene surfaces correlate roughly to observed mound locations. This study demonstrates the applicability of basin modelling in testing and identifying geologic processes related to geosphere/biosphere interactions.

  3. Dust and Black Carbon Radiative Forcing Controls on Snowmelt in the Colorado River Basin

    OpenAIRE

    Skiles, Sara McKenzie

    2014-01-01

    Light absorbing impurities (LAIs), like dust and black carbon (BC), initiate powerful albedo feedbacks when deposited on snow cover, yet due to a scarcity of observations radiative forcing by LAIs is often neglected, or poorly constrained, in climate and hydrological models. This has important consequences for regions like the Colorado River Basin, where dust deposition to mountain snow cover frequently occurs in the upper basin in the springtime, a relatively new phenomenon since western exp...

  4. Composition and origin of authigenic carbonates in the Krishna-Godavari and Mahanadi Basins, eastern continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Teichert, B.M.A.; Johnson, J.E.; Solomon, E.A.; Giosan, L.; Rose, K.; Kocherla, M.; Connolly, E.C.; Torres, M.E.

    The mineralogical and stable isotopic composition of authigenic carbonates from the KrishnaeGodavari (KG) and Mahanadi Basin provide a deeper insight into the processes inducing carbonate formation in the sediments of the eastern continental margin...

  5. Advanced Characterization of Fractured Reservoirs in Carbonate Rocks: The Michigan Basin

    Energy Technology Data Exchange (ETDEWEB)

    Wood, James R.; Harrison, William B.

    2000-10-24

    The main objective of this project is for a university-industry consortium to develop a comprehensive model for fracture carbonate reservoirs based on the ''data cube'' concept using the Michigan Basin as a prototype. This project combined traditional historical data with 2D and 3D seismic data as well as data from modern logging tools in a novel way to produce a new methodology for characterizing fractured reservoirs in carbonate rocks. Advanced visualization software was used to fuse the data and to image it on a variety of scales, ranging from basin-scale to well-scales.

  6. Selected Basin Characterization Model Parameters for the Great Basin Carbonate and Alluvial Aquifer System of Nevada, Utah, and Parts of Adjacent States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on ground-water resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  7. Carbon-Water-Energy Relations for Selected River Basins

    Science.gov (United States)

    Choudhury, B. J.

    1998-01-01

    A biophysical process-based model was run using satellite, assimilated and ancillary data for four years (1987-1990) to calculate components of total evaporation (transpiration, interception, soil and snow evaporation), net radiation, absorbed photosynthetically active radiation and net primary productivity over the global land surface. Satellite observations provided fractional vegetation cover, solar and photosynthetically active radiation incident of the surface, surface albedo, fractional cloud cover, air temperature and vapor pressure. The friction velocity and surface air pressure are obtained from a four dimensional data assimilation results, while precipitation is either only surface observations or a blended product of surface and satellite observations. All surface and satellite data are monthly mean values; precipitation has been disaggregated into daily values. All biophysical parameters of the model are prescribed according to published records. From these global land surface calculations results for river basins are derived using digital templates of basin boundaries. Comparisons with field observations (micrometeorologic, catchment water balance, biomass production) and atmospheric water budget analysis for monthly evaporation from six river basins have been done to assess errors in the calculations. Comparisons are also made with previous estimates of zonal variations of evaporation and net primary productivity. Efficiencies of transpiration, total evaporation and radiation use, and evaporative fraction for selected river basins will be presented.

  8. Conventional tree height-diameter relationships significantly overestimate aboveground carbon stocks in the Central Congo Basin

    Science.gov (United States)

    Kearsley, Elizabeth; Hufkens, Koen; Steppe, Kathy; Beeckman, Hans; Boeckx, Pascal; Verbeeck, Hans

    2014-05-01

    Accurate estimates of the amount of carbon stored in tropical forests represent crucial baseline data for recent climate change mitigation policies. Such data are needed to quantify possible emissions due to deforestation and forest degradation, and to evaluate the potential of these forests to act as carbon sinks. Currently, only rough estimates of the carbon stocks for Central African tropical forests are available due to a lack of field data, and little is known about the response of these stocks to climate change. We present the first field-based carbon stock data for the Central Congo Basin in Yangambi, Democratic Republic of Congo. We found an average aboveground carbon stock of 162 ± 20 Mg C ha-1 for intact old-growth forest, which is significantly lower than stocks recorded in the outer regions of the Congo Basin. The best available tree height-diameter relationships derived for Central Africa do not render accurate canopy height estimates for our study area. Aboveground carbon stocks would be overestimated by 24% if these inaccurate relationships were used. The studied forests have a lower stature compared with forests in the outer regions of the basin, which confirms remotely sensed patterns. We identified a significant difference in height-diameter relations across the Congo Basin as a driver for spatial differences in carbon stocks. The study of a more detailed interaction of the environment and the available tree species pool as drivers for differences in carbon storage could have large implications. The effect of the species pool on carbon storage can be large since species differ in their ability to sequester carbon, and the collective functional characteristics of plant communities could be a major driver of carbon accumulation. Numerous species-specific tree height-diameter relations are established for two sites around Kisangani, central Congo Basin, with differing stand height-diameter relationships. The species-specific relations for the two

  9. Tectonic evolution and paleokarstification of carbonate rocks in the Paleozoic Tarim Basin.

    Science.gov (United States)

    Xu, Xuhui; Chen, Qianglu; Chu, Chenglin; Li, Guorong; Liu, Cunge; Shi, Zheng

    2017-01-01

    Thick carbonate rocks were developed in the depression of the Tarim craton during the Cambrian-Middle Ordovician periods. The compressional tectonic movement during the Middle Caledonian-Hercynian created the paleouplifts, which became the base for the paleokarst in the Ordovician carbonate rocks. Based on the large quantity of seismic, drilling, and geological outcrop data, this study analyzed the paleokarst development in relation to the multi-stage tectonic movements in the Paleozoic Era and different stages of karstification and hypothesized paleogeomorphology and paleokarst water system of those stages. Fractures from the tectonic movements in the carbonate and non-carbonate rocks were essential for water cycle, and therefore, the karst development in deep carbonate rocks. Paleokarsts in the Tarim Basin can be classified into four major types based on the paleogeomorphology, degree of karstification, and the layering, i.e., Tahe type, gentle hill type, high steep hill type, and covered-semi-open type. Relatively, the Tahe type was mostly on hill slopes and had the strongest karstification, the gentle hill type often located in the plain areas or basin bottoms and had least karstification, the high steep hill type was controlled by faults and had medium karstification, the semi-open type was controlled by precipitation and hydraulic gradient, and fracture passages and karst caves were mostly developed along major fractures. Overall, the paleokarsts of the Ordovician carbonate rocks in the Tarim Basin can be characterized by long geologic history, multiple development stages, deep burial depth, and various karst types.

  10. Distribution and origin of suspended matter and organic carbon pools in the Tana River Basin, Kenya

    NARCIS (Netherlands)

    Tamooh, F.; Van den Meersche, K.; Meysman, F.; Marwick, T.R.; Borges, A.V.; Merckx, R.; Dehairs, F.; Schmidt, S.; Nyunja, J.; Bouillon, S.

    2012-01-01

    We studied patterns in organic carbon pools and their origin in the Tana River Basin (Kenya), in February 2008 (dry season), September–November 2009 (wet season), and June–July 2010 (end of wet season), covering the full continuum from headwater streams to lowland mainstream sites. A consistent

  11. Mississippi Basin Carbon Project; upland soil database for sites in Yazoo Basin, northern Mississippi

    Science.gov (United States)

    Harden, J.W.; Fries, T.L.; Huntington, T.G.

    1999-01-01

    The conversion of land from its native state to an agricultural use commonly results in a significant loss of soil carbon (Mann, 1985; Davidson and Ackerman, 1993). Globally, this loss is estimated to account for as much as 1/3 of the net CO2 emissions for the period of 1850 to 1980 (Houghton et al, 1983). Roughly 20 to 40 percent of original soil carbon is estimated to be lost as CO2 as a result of agricultural conversion, or 'decomposition enhancement', and global models use this estimate along with land conversion data to provide agricultural contributions of CO2 emissions for global carbon budgets (Houghton and others, 1983; Schimel, 1995). As yet, erosional losses of carbon are not included in global carbon budgets explicitly as a factor in land conversion nor implicitly as a portion of the decomposition enhancement. However, recent work by Lal et al (1995) and by Stallard (1998) suggests that significant amounts of eroded soil may be stored in man-made reservoirs and depositional environments as a result of agricultural conversion. Moreover, Stallard points out that if eroding soils have the potential for replacing part of the carbon trapped in man-made reservoirs, then the global carbon budget may grossly underestimate or ignore a significant sink term resulting from the burial of eroded soil. Soil erosion rates are significantly (10X) higher on croplands than on their undisturbed equivalents (Dabney et al, 1997). Most of the concern over erosion is related to diminished productivity of the uplands (Stallings, 1957; McGregor et al, 1993; Rhoton and Tyler, 1990) or to increased hazards and navigability of the lowlands in the late 1800's to early 1900's. Yet because soil carbon is concentrated at the soil surface, with an exponential decline in concentration with depth, it is clear that changes in erosion rates seen on croplands must also impact soil carbon storage and terrestrial carbon budgets as well.

  12. Mississippi Basin Carbon Project: upland soil database for sites in Nishnabotna River basin, Iowa

    Science.gov (United States)

    Harden, J.W.; Fries, T.L.; Haughy, R.; Kramer, L.; Zheng, Shuhui

    2001-01-01

    The conversion of land from its native state to an agricultural use commonly results in a significant loss of soil carbon (Mann, 1985; Davidson and Ackerman, 1993). Globally, this loss is estimated to account for as much as 1/3 of the net CO2 emissions for the period of 1850 to 1980 (Houghton and others, 1983). Roughly 20 to 40 percent of original soil carbon is estimated to be lost as CO2 as a result of agricultural conversion, or "decomposition enhancement". Global models use this estimate along with land conversion data to provide agricultural contributions of CO2 emissions for global carbon budgets (Houghton and others, 1983; Schimel, 1995). Soil erosion rates are significantly (10X) higher on croplands than on their undisturbed equivalents (Dabney and others, 1997). Most of the concern over erosion is related to diminished productivity of the uplands (Stallings, 1957; McGregor and others, 1969; Rhoton, 1990) or to increased hazards and navigability of the lowlands in the late 1800's to early 1900's. Yet because soil carbon is concentrated at the soil surface, with an exponential decline in concentration with depth (Harden et al, 1999), it is clear that changes in erosion rates seen on croplands must also impact soil carbon storage and terrestrial carbon budgets as well. As yet, erosional losses of carbon are not included in global carbon budgets explicitly as a factor in land conversion nor implicitly as a portion of the decomposition enhancement. However, recent work by Lal and others (1995) and by Stallard (1998) suggests that significant amounts of eroded soil may be stored in man-made reservoirs and depositional environments as a result of agricultural conversion. Moreover, Stallard points out that eroding soils have the potential for replacing part of the carbon trapped in man-made reservoirs. If true, then the global carbon budget may grossly underestimate or ignore a significant sink term resulting from the burial of eroded soil.

  13. The South Pyrenean Eocene carbonate megabreccias revisited: new interpretation based on evidence from the Pamplona Basin

    Science.gov (United States)

    Payros, Aitor; Pujalte, Victoriano; Orue-Etxebarria, Xabier

    1999-05-01

    The South Pyrenean Foreland Basin contains numerous units of Eocene carbonate megabreccias intercalated with siliciclastic turbidites and derived by resedimentation of shallow-marine carbonate platforms. Previous studies were limited mainly to the foreland eastern part, known as the Jaca Basin. The present study from the Pamplona Basin, a western part of the foreland trough, sheds new light on the origin and regional significance of these South Pyrenean Eocene carbonate megabreccias (SPECMs). The number of the SPECM units in the foreland basin is higher than previously recognized and their age is somewhat older than originally assumed. The SPECM units appear to occur as time-stratigraphic clusters, which can be correlated with the relative sea-level lowstands and linked with phases of tectonic activity. The megabreccias were derived from a carbonate-platform system hosted by the foreland basin's southern (passive) margin. The episodic instability and mass wasting were triggered by phases of structural steepening (forebulge uplift) accompanied by high-magnitude earthquakes, with the former causing platform emergence, increased load stresses and excess pore-water pressure in the carbonate ramp. The SPECM deposits were emplaced by cohesive debris flows evolving into high-density turbidite currents. An ideal SPECM unit consists of (1) an immature, homogeneous debrite in the proximal part; (2) a differentiated, bipartite debrite and turbidite in the medial part; and (3) an incomplete, base-missing debrite overlain by turbidite, or a turbidite alone, in the distal part. The debrite component volumetrically predominates in the SPECM units, and the original terms `megaturbidite' and `seismoturbidite' thus seem to be inappropriate for these deposits.

  14. The carbonate reservoirs in the Permian halogenic formation in the Dnepr Donetsk basin

    Energy Technology Data Exchange (ETDEWEB)

    Ryabykh, O.F.; Priymenko, A.F.

    1984-01-01

    In the exploration of the gas formations in the Slavyansk formation of the Permian halogen formations in the Dnepr Donetsk basin, a new genetic type of carbonate reservoir is discovered. This type was porous analogs of halite carbonate rock. When dissolving the halite component using formation waters, the porosity value for this rock exceeds 28 percent. The mineral composition of the rock is predominantly dolomite or magnesite with a higher or lower concentration of terrigenous material, calcite, anhydrite and halite; the ferrous sulfides are encountered in excessory quantities. Commercial gas production is realized at the Melikhov field from the Podbryantsev block in the Slavyansk formation, which includes porous analogs of halite carbonate rock.

  15. Sinemurian–Pliensbachian calcareous nannofossil biostratigraphy and organic carbon isotope stratigraphy in the Paris Basin

    DEFF Research Database (Denmark)

    Peti, Leonie; Thibault, Nicolas Rudolph; Clemence, Marie-Emilie

    2017-01-01

    organic carbon isotope curve based on 385 data points. The main bioevents, i.e. the first occurrences of Parhabdolithus liasicus, Crepidolithus pliensbachensis, Crepidolithus crassus, Mitrolithus lenticularis, Similiscutum cruciulus sensu lato, Lotharingius hauffii, Crepidolithus cavus and Lotharingius...... carbon isotope excursions are identified and defined in the Paris Basin including the well-documented Sinemurian–Pliensbachian boundary event. One positive excursion is further defined in the Pliensbachian interval. Our calibration of high-resolution calcareous nannofossil biostratigraphy to ammonite...... biostratigraphy and organic carbon isotopes represents a new stratigraphic reference for the Lower Jurassic series....

  16. Multi-property modeling of ocean basin carbon fluxes

    Science.gov (United States)

    Volk, Tyler

    1988-01-01

    The objectives of this project were to elucidate the causal mechanisms in some of the most important features of the global ocean/atomsphere carbon system. These included the interaction of physical and biological processes in the seasonal cycle of surface water pCo2, and links between productivity, surface chlorophyll, and the carbon cycle that would aid global modeling efforts. In addition, several other areas of critical scientific interest involving links between the marine biosphere and the global carbon cycle were successfully pursued; specifically, a possible relation between phytoplankton emitted DMS and climate, and a relation between the location of calcium carbonate burial in the ocean and metamorphic source fluxes of CO2 to the atmosphere. Six published papers covering the following topics are summarized: (1) Mass extinctions, atmospheric sulphur and climatic warming at the K/T boundary; (2) Sensitivity of climate and atmospheric CO2 to deep-ocean and shallow-ocean carbonate burial; (3) Controls on CO2 sources and sinks in the earthscale surface ocean; (4) pre-anthropogenic, earthscale patterns of delta pCO2 between ocean and atmosphere; (5) Effect on atmospheric CO2 from seasonal variations in the high latitude ocean; and (6) Limitations or relating ocean surface chlorophyll to productivity.

  17. Linking carbon storage with functional diversity in tropical rainforest in the central Congo Basin

    Science.gov (United States)

    Verbeeck, Hans; Kearsley, Elizabeth; Bauters, Marijn; Beeckman, Hans; Huygens, Dries; Steppe, Kathy; Boeckx, Pascal

    2015-04-01

    This presentation will show an overview of results of the COBIMFO project (Congo basin integrated monitoring for forest carbon mitigation and biodiversity). In the framework of this project we have established 21 permanent 1 ha sampling plots in different forest types in the Yangambi reserve. This UNESCO Man and Biosphere reserve has an area of more than 6000 km² and is located in the heart of the Congo Basin near the Yangambi research station (DR Congo). Analysis of the inventory data of these plots revealed that carbon stocks in mature forests in this area of the Congo Basin are significantly lower (24%) than stocks recorded in the outer regions of the basin. These lower stocks are attributed to a lower maximal tree height (Kearsley et al. 2013). In addition to the carbon inventories we collected leaf and wood samples on all species within 95% basal area of each of the Yangambi plots. A total of 995 individuals were sampled, covering 123 tree species. On the samples we measured 15 traits related to leaf and wood morphology and functioning. In the presented study, relationships between the observed functional diversity and biomass are analysed. One of the remarkable results of our analysis is that species with a high functional distinctiveness have a low contribution to the basal area and the carbon stocks. In contrast, species with a high contribution to the carbon stock have a low contribution to the functional diversity. Similar patterns have been observed elsewhere (e.g. Amazon basin), but are now for the first time confirmed for central African rainforest. Finally, we also present the first results of an analysis of carbons stocks and functional diversity in tropical plantations from a unique 70-years old tree diversity experiment that was established during the colonial period at the Yangambi research station. Kearsley, E., de Haulleville, T., Hufkens, K., Kidimbu, A., Toirambe, B., Baert, G., Huygens, D., Kebede, Y., Defourny, P., Bogaert, J., Beeckman, H

  18. Trace fossils from Talchir carbonate concretions, Giridih basin ...

    Indian Academy of Sciences (India)

    The carbonate concretions of various shapes and sizes are found in the ... matrix supported conglomerate with angular clasts. It laterally as well as vertically changes to fine grained, yel- lowish, feldspathic sandstone with spo- radic pebbles. Sandstone shows parallel ... diamictite with negligible clast con- tent. The diamictite ...

  19. Trace fossils from the Talchir carbonate concretions, Giridih Basin ...

    Indian Academy of Sciences (India)

    The carbonate concretions occurring at the bottom of Talchir fissile shale facies preserved signatures of various trace fossils along with a cast of doubtful organisms and cyanobacterial mat structures. The host shale deposited under glacial melt water fed lacustrine condition.The concretions,formed in poorly oxygenated ...

  20. [Transported fluxes of the riverine carbon and seasonal variation in Pearl River basin].

    Science.gov (United States)

    Zhang, Lian-Kai; Qin, Xiao-Qun; Yang, Hui; Huang, Qi-Bo; Liu, Peng-Yu

    2013-08-01

    The riverine carbon flux is a critical component of global carbon cycle. Riverine water samples were collected from eleven hydrometric stations in the main stream of Pearl River and its tributaries during April and July, 2012. The samples were analyzed for the space and seasonal distribution characteristics of the riverine suspended substance and carbon compositions. Carbon fluxes and erosion modulus of Pearl River basin were also estimated in Boluo, Shijiao, Gaoyao, namely Dongjiang, Beijiang, Xijiang, in these two hydrological seasons. The results showed that the total suspended substance (TSS) and organic carbon, including total particulate organic carbon (POC) and dissolved organic carbon (DOC) have higher concentration in the high-water season than that in the normal-water season. Dissolved inorganic carbon (DIC) has an overwhelming concentration compared to other carbon compositions in Pearl River basin. The DIC concentration shows an order of Xijiang, Beijiang and Dongjiang from high to low. The percentage of allogenic POC in Xijiang, Beijiang and Dongjiang are 78%, 72%, 26%, respectively, and C3 plants are the main sources of allogenic POC in those three tributaries. The transported fluxes of TSS, total carbon (TC), POC, particulate inorganic carbon (PIC), DOC, DIC, total particulate carbon (TPC) and total organic carbon (TOC) are 134 x 10(12),12.69 x 10(12), 2.50 x 10(12), 1.01 x 10(12), 1.13 x 10(12), 8.05 x 10(12), 3.51 x 10(12) and 3.65 x 10(12) g x a(-1), respectively, and the erosion modulus of those compositions are 309 x 10(6), 28.98 x 10(6), 5.75 x 10(6), 2.27 x 10(6), 2.56 x 10(6), 18.4 x 10(6), 8.02 x 10(6) and 8.31 x 10(6) g x (km2 x a)(-1), respectively. Compared with average values of global large rivers, the erosion modulus of DOC, POC, and TOC in Pearl River basin are higher than the corresponding values.

  1. 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.

    2017-01-01

    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 × 1015 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

  2. Carbonate replacement of lacustrine gypsum deposits in two Neogene continental basins, eastern Spain

    Science.gov (United States)

    Anadón, P.; Rosell, L.; Talbot, M. R.

    1992-07-01

    Bedded nonmarine gypsum deposits in the Miocene Teruel and Cabriel basins, eastern Spain, are partly replaced by carbonate. The Libros gypsum (Teruel Graben) is associated with fossiliferous carbonate wackestones and finely laminated, organic matter-rich mudstones which accumulated under anoxic conditions in a meromictic, permanent lake. The gypsum is locally pseudomorphed by aragonite or, less commonly, replaced by calcite. Low δ 13C values indicate that sulphate replacement resulted from bacterial sulphate reduction processes that were favoured by anacrobic conditions and abundant labile organic matter in the sediments. Petrographic evidence and oxygen isotopic composition suggest that gypsum replacement by aragonite occurred soon after deposition. A subsequent return to oxidising conditions caused some aragonite to be replaced by diagenetic gypsum. Native sulphur is associated with some of these secondary gypsum occurrences. The Los Ruices sulphate deposits (Cabriel Basin) contain beds of clastic and selenitic gypsum which are associated with limestones and red beds indicating accumulation in a shallow lake. Calcite is the principal replacement mineral. Bacterial sulphate reduction was insignificant in this basin because of a scarcity of organic matter. Stable isotope composition of diagenetic carbonate indicates that gypsum replacement occurred at shallow burial depths due to contact with dilute groundwaters of meteoric origin. Depositional environment evidently has a major influence upon the diagenetic history of primary sulphate deposits. The quantity of preserved organic matter degradable by sulphate-reducing bacteria is of particular importance and, along with groundwater composition, is the main factor controlling the mechanism of gypsum replacement by carbonate.

  3. Steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system

    Science.gov (United States)

    Brooks, Lynette E.; Masbruch, Melissa D.; Sweetkind, Donald S.; Buto, Susan G.

    2014-01-01

    This report describes the construction, calibration, evaluation, and results of a steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system that was developed as part of the U.S. Geological Survey National Water Census Initiative to evaluate the nation’s groundwater availability. The study area spans 110,000 square miles across five states. The numerical model uses MODFLOW-2005, and incorporates and tests complex hydrogeologic and hydrologic elements of a conceptual understanding of an interconnected groundwater system throughout the region, including mountains, basins, consolidated rocks, and basin fill. The level of discretization in this model has not been previously available throughout the study area.

  4. A survey of the carbonate system in the Levantine Mediterranean Sub-basin

    Science.gov (United States)

    El Rahman Hassoun, Abed; Gemayel, Elissar; Abboud-Abi Saab, Marie

    2016-04-01

    The carbonate system is very important since it regulates the pH of the seawater and controls the circulation of CO2 between the various natural reservoirs. Recently, several oceanographic cruises have been carried out to assess this system in the Mediterranean Sea. However, the measurements undertaken to quantify the carbonate system parameters in the Levantine Sub-basin remain scarce and occasional. In our study, we are compiling the occasional data taken near Lebanon and surveying the carbonate system in the Lebanese seawaters for the first time by fixing two stations off the Lebanese coast to study the monthly and annual variations of this system through the water column. The dominant processes changing the carbonate chemistry of a seawater can be described by considering changes in the total alkalinity (AT) and the total dissolved inorganic carbon (CT). To measure these parameters, the collected seawater samples are titrated via potentiometric acid titration using a closed cell (DOE, 1994). Further, the temperature and the salinity are measured in situ. Dissolved oxygen concentrations are measured using a Winkler iodometric titration. Nutrients (phosphates, nitrates, nitrites), chlorophyll a and phytoplankton populations are also studied. The compilation of the carbonate system data taken from the cruises conducted near Cyprus (MedSeA 2013, Meteor 84-3, BOUM, Meteor 51-2) indicate that the AT and CT averages are equal to 2617 ±15 and 2298 ± 9 μmol kg-1 respectively, showing high AT and CT concentrations compared to those measured in other Mediterranean sub-basins. Our survey will provide a brand new dataset that will be useful to better comprehend the carbonate system in the Mediterranean Sea in general and the actual situation of the water masses formation in the Levantine Sub-basin after the Eastern Mediterranean Transient (EMT) in particular. Moreover, this work will permit us to estimate the air-sea fluxes and to estimate the anthropogenic CO2

  5. Mesozoic carbonate-siliciclastic platform to basin systems of a South Tethyan margin (Egypt, East Mediterranean)

    Science.gov (United States)

    Tassy, Aurélie; Crouzy, Emmanuel; Gorini, Christian; Rubino, Jean-Loup

    2015-04-01

    The Mesozoïc Egyptian margin is the south margin of a remnant of the Neo-Tethys Ocean, at the African northern plate boundary. East Mediterranean basin developed during the late Triassic-Early Jurassic rifting with a NW-SE opening direction (Frizon de Lamotte et al., 2011). During Mesozoïc, Egypt margin was a transform margin with a NW-SE orientation of transform faults. In the Eastern Mediterranean basin, Mesozoïc margins are characterized by mixed carbonate-siliciclastics platforms where subsidence and eustacy are the main parameters controlling the facies distribution and geometries of the platform-to-basin transition. Geometries and facies on the platform-slope-basin system, today well constrained on the Levant area, where still poorly known on the Egyptian margin. Geometries and stratigraphic architecture of the Egyptian margin are revealed, thanks to a regional seismic and well data-base provided by an industrial-academic group (GRI, Total). The objective is to understand the sismostratigraphic architecture of the platform-slope-basin system in a key area from Western Desert to Nile delta and Levant margin. Mapping of the top Jurassic and top Cretaceous show seismic geomorphology of the margin, with the cartography of the hinge line from Western Desert to Sinaï. During the Jurassic, carbonate platform show a prograding profile and a distally thickening of the external platform, non-abrupt slope profiles, and palaeovalleys incisions. Since the Cretaceous, the aggrading and retrograding mixed carbonate-siliciclastic platform show an alternation of steep NW-SE oblique segments and distally steepened segments. These structures of the platform edge are strongly controlled by the inherited tethyan transform directions. Along the hinge line, embayments are interpreted as megaslides. The basin infilling is characterised by an alternation of chaotic seismic facies and high amplitude reflectors onlaping the paleoslopes. MTC deposits can mobilize thick sedimentary

  6. Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Kang Xu

    2015-09-01

    Full Text Available Oil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data. Geochemical analysis included the major, trace, and rare earth elements; fluid inclusion thermometry; clay mineral characterization; and carbon and oxygen isotopes of the carbonate rocks. Homogenization temperatures of the fluid inclusions of Well He-3 in the Bachu area indicate three groups, 60–80 °C, 90–130 °C, and 140–170 °C, and suggest that the carbonate rocks experienced modification due to heating events. The porosity in the reservoir is defined by fractures and secondary pores, and there is a notable increase in the porosity of the carbonate reservoirs in proximity to magmatic intrusion, particularly approximately 8–10 m from the intrusive rocks. The development of secondary pores was controlled by lithofacies and corrosion by various fluids. We identify supercritical fluids with high density (138.12–143.97 mg/cm3 in the Bachu area. The negative correlations of δ13C (−2.76‰ to −0.97‰ and δ18O (−7.91‰ to −5.07‰ suggest that the carbonate rocks in the study area were modified by high-salinity hydrothermal fluid. The formation of clay minerals, such as illite and montmorillonite, caused a decrease in porosity. Our study demonstrates the effect of magmatic intrusions in modifying the reservoir characteristics of carbonate rocks and has important implications for oil and gas exploration.

  7. Hydrological controls on chemical weathering in the typical carbonated river basin, SW China

    Science.gov (United States)

    LI, S. L.; Jin, L.; Zhong, J., Sr.

    2016-12-01

    The dynamics of dissolved load in the riverine system could provide an insight in understanding the surface processes, such as chemical weathering and carbon cycle. The Xijiang River is a typical carbonated river basin, located at southwestern China. The Xijiang River catchment is controlled by a humid subtropical climate. In spite of being impacted by monsoonal climate and with significant variations of discharge, the temporal variations of compositions of main ions and chemical weathering of Xijiang River are rarely documented. In this study, a systematic investigation on the seasonal and episodic water geochemistry (major ions and d13CDIC) of the major branch and outlet of Xijiang River were carried out with the purpose of 1) characterizing temporal variations of aqueous geochemistry and its controlling factors, 2) exploring the impact of hydrological controls on chemical weathering of the Xijiang River Basin. The results show that the concentrations of Cl, Na, Ca, Mg, and HCO3 are generally decreased during monsoon season, which should be mainly caused by dilution. However, the dilution effect does not strictly follow the theoretical dilution curve. Moreover, d13CDIC in the high-flow period has more negative values than in low-flow period. More negative δ13CDIC values in the river during the wet season reflected the influx of rain water with biological CO2 during the rain event. This study suggested that hydrochemistry and d13CDIC had a large variation responding to rainstorm events. The calculated results show that the weathering rates of silicate and carbonate as well as that of related CO2 consumption have a positive relation with water discharge, highlighting the hydrological controls on chemical weathering and CO2 consumption rates. The results indicated carbonated weathering rate responding to hydrological condition sensitivity in the typical carbonate river basin. This work was supported by The China National Science Fund for Outstanding Young Scholars

  8. Characteristics of hydrothermal activity in the Tarim Basin and its reworking effect on carbonate reservoirs

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2016-05-01

    Full Text Available Hydrothermal activity is common in the Tarim Basin. In this paper, petrologic and geochemical features of the hydrothermal products in the carbonate rocks in this basin were analyzed so as to figure out the effect of hydrothermal activity on the Lower Palaeozoic carbonate reservoirs in this area. It is shown that the hydrothermal fluids in the Tarim Basin are generally high in CO2 content, but very low in Mg2+ content. Then, the reworking effect of hydrothermal activity on reservoir was further discussed. It is indicated that the component of hydrothermal fluid is the deciding factor for the reworking of reservoirs. The study provided the following findings. Firstly, hydrothermal fluid is rich in CO2. Dissolution is intense in the vicinity of fracture zones and dissolved pores of different sizes are developed. Therefore, small-scale high-quality reservoirs with good porosity and permeability are formed. Secondly, hydrothermal fluid itself is low in magnesium content and some additional magnesium can be produced from Cambrian dolomites by means of dissolution, but the scale of hydrothermal dolomitization is small. Thirdly, the hydrothermal fluids rich in CO2 form high-quality dissolved vug typed reservoirs by means of dissolving surrounding rocks and their distribution are controlled by faulting. Fourthly, the saddle-like dolomite with hydrothermal origin fills dissolved vugs. Furthermore, the hydrothermal activity in the vicinity of faults results in the recrystallization or excessive growth of dolomite crystal, blocking existed pores, which is a type of destructive diagenesis as a whole. The study results can provide a reference for carbonate reservoir prediction of deep basin.

  9. Manganese carbonates in the Upper Jurassic Georgiev Formation of the Western Siberian marine basin

    Science.gov (United States)

    Eder, Vika G.; Föllmi, Karl B.; Zanin, Yuri N.; Zamirailova, Albina G.

    2018-01-01

    Manganese (Mn) carbonate rocks are a common lithological constituent of the Upper Oxfordian to Lower Tithonian (Volgian) Georgiev Formation of the Western Siberian marine basin (WSMB). The Mn carbonates in the Georgiev Formation are present in the form of massive sediments, stromatolites, and oncolites, and are associated with glauconite and partly also phosphate-rich clay- and siltstones. Unlike most Mn carbonates, they are not directly associated with organic-rich sediments, but occur below an organic-rich succession (Bazhenov Formation). The Mn carbonate occurrences can be traced from the western central area of the WSMB to its center along a distance of at least 750 km. The thickness of the Mn carbonates and their Mn contents becomes reduced in an eastward direction, related to increased detrital input. The geochemical and mineralogical heterogeneity within the Mn carbonates indicates that they were deposited stepwise in a diagenetic regime characterized by steep gradients in Mn, Ca, and Mg. A first step consisted in the replacement of initial sediments within the microbialites during an early diagenetic stage, followed by a second step where massive sediments were transformed into Mn carbonate. During both steps, the decomposition of organic matter was an important source of the newly formed carbonate. During a further step, voids were cemented by Mn carbonates, which are rich in pyrite. This last generation may only have formed once the organic-rich sediments of the overlying Bazhenov Formation were deposited. Accumulation of the Mn carbonates in the Upper Jurassic WSMB was controlled by the proximity of Mn-enriched parent rocks, likely in the Ural, which were subjected to intense geochemical weathering during the Late Jurassic.

  10. Annual Carbon Emissions from Deforestation in the Amazon Basin between 2000 and 2010.

    Science.gov (United States)

    Song, Xiao-Peng; Huang, Chengquan; Saatchi, Sassan S; Hansen, Matthew C; Townshend, John R

    2015-01-01

    Reducing emissions from deforestation and forest degradation (REDD+) is considered one of the most cost-effective strategies for mitigating climate change. However, historical deforestation and emission rates-critical inputs for setting reference emission levels for REDD+-are poorly understood. Here we use multi-source, time-series satellite data to quantify carbon emissions from deforestation in the Amazon basin on a year-to-year basis between 2000 and 2010. We first derive annual deforestation indicators by using the Moderate Resolution Imaging Spectroradiometer Vegetation Continuous Fields (MODIS VCF) product. MODIS indicators are calibrated by using a large sample of Landsat data to generate accurate deforestation rates, which are subsequently combined with a spatially explicit biomass dataset to calculate committed annual carbon emissions. Across the study area, the average deforestation and associated carbon emissions were estimated to be 1.59 ± 0.25 M ha•yr(-1) and 0.18 ± 0.07 Pg C•yr(-1) respectively, with substantially different trends and inter-annual variability in different regions. Deforestation in the Brazilian Amazon increased between 2001 and 2004 and declined substantially afterwards, whereas deforestation in the Bolivian Amazon, the Colombian Amazon, and the Peruvian Amazon increased over the study period. The average carbon density of lost forests after 2005 was 130 Mg C•ha(-1), ~11% lower than the average carbon density of remaining forests in year 2010 (144 Mg C•ha(-1)). Moreover, the average carbon density of cleared forests increased at a rate of 7 Mg C•ha(-1)•yr(-1) from 2005 to 2010, suggesting that deforestation has been progressively encroaching into high-biomass lands in the Amazon basin. Spatially explicit, annual deforestation and emission estimates like the ones derived in this study are useful for setting baselines for REDD+ and other emission mitigation programs, and for evaluating the performance of such efforts.

  11. LBNL deliverable to the Tricarb carbon sequestration partnership: Final report on experimental and numerical modeling activities for the Newark Basin

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, Sumit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spycher, Nicolas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pester, Nick [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Saldi, Giuseppe [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Beyer, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Houseworth, Jim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Knauss, Kevin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-09-04

    This report presents findings for hydrological and chemical characteristics and processes relevant to large-scale geologic CO2 sequestration in the Newark Basin of southern New York and northern New Jersey. This work has been conducted in collaboration with the Tri-Carb Consortium for Carbon Sequestration — comprising Sandia Technologies, LLC; Conrad Geoscience; and Schlumberger Carbon Services.

  12. Lacustrine cave carbonates: Novel archives of paleohydrologic change in the Bonneville Basin (Utah, USA)

    Science.gov (United States)

    McGee, David; Quade, Jay; Edwards, R. Lawrence; Broecker, Wallace S.; Cheng, Hai; Reiners, Peter W.; Evenson, Nathan

    2012-10-01

    Records of past changes in lake levels and lake water isotopic composition in closed basins provide key insights into past variations in the hydrological cycle; however, these records are often limited by dating precision and temporal resolution. Here we present data from lacustrine cave carbonates, a previously unexplored class of carbonates that comprise a promising new archive of past hydrologic changes in the Bonneville Basin of the northeastern Great Basin (USA). These dense carbonates precipitated within caves, crevices, and other protected spaces flooded by Lake Bonneville during its highstand in the last glacial period. We report on deposits in Cathedral and Craners caves, located ˜50 km apart at similar elevations approximately 100 m above the modern Great Salt Lake and almost 200 m below Lake Bonneville's highstand shoreline. Carbonates from the two caves show similar chronologies, mineralogical transitions, isotopic compositions, and uranium concentrations. These findings suggest that lacustrine cave carbonates record changes in lake level and in the isotopic composition and chemistry of lake water. Importantly, the deposits can be precisely dated by U-Th methods, providing the first records of Lake Bonneville's water balance changes tied to precise U-Th ages. Close agreement between paired U-Th and calibrated 14C ages in the deposits suggests a minimal (influx of freshwater during Heinrich Stadial 2. A hiatus in deposition beginning at 18.2±0.3 ka may be the result of freshening related to the lake's overflow. Calcite deposition resumes at Cathedral Cave at 16.4±0.2 ka, suggesting that basin overflow had ceased by this time and that the lake's calcite saturation state had increased, and δ18O values increase markedly after 15.9 ka, consistent with drying at this time. These data imply that the lake's deglacial regression began well before the Bølling warming. Cessation of this second phase of deposition at 14.7±0.2 ka, coincident with the B

  13. Environmental impact and magnitude of paleosol carbonate carbon isotope excursions marking five early Eocene hyperthermals in the Bighorn Basin, Wyoming

    Science.gov (United States)

    Abels, Hemmo A.; Lauretano, Vittoria; van Yperen, Anna E.; Hopman, Tarek; Zachos, James C.; Lourens, Lucas J.; Gingerich, Philip D.; Bowen, Gabriel J.

    2016-05-01

    Transient greenhouse warming events in the Paleocene and Eocene were associated with the addition of isotopically light carbon to the exogenic atmosphere-ocean carbon system, leading to substantial environmental and biotic change. The magnitude of an accompanying carbon isotope excursion (CIE) can be used to constrain both the sources and amounts of carbon released during an event and also to correlate marine and terrestrial records with high precision. The Paleocene-Eocene Thermal Maximum (PETM) is well documented, but CIE records for the subsequent warming events are still rare, especially from the terrestrial realm.Here, we provide new paleosol carbonate CIE records for two of the smaller hyperthermal events, I1 and I2, as well as two additional records of Eocene Thermal Maximum 2 (ETM2) and H2 in the Bighorn Basin, Wyoming, USA. Stratigraphic comparison of this expanded, high-resolution terrestrial carbon isotope history to the deep-sea benthic foraminiferal isotope records from Ocean Drilling Program (ODP) sites 1262 and 1263, Walvis Ridge, in the southern Atlantic Ocean corroborates the idea that the Bighorn Basin fluvial sediments record global atmospheric change. The ˜ 34 m thicknesses of the eccentricity-driven hyperthermals in these archives corroborate precession forcing of the ˜ 7 m thick fluvial overbank-avulsion sedimentary cycles. Using bulk-oxide mean-annual-precipitation reconstructions, we find soil moisture contents during the four younger hyperthermals that are similar to or only slightly wetter than the background, in contrast with soil drying observed during the PETM using the same proxy, sediments, and plant fossils.The magnitude of the CIEs in soil carbonate for the four smaller, post-PETM events scale nearly linearly with the equivalent event magnitudes documented in marine records. In contrast, the magnitude of the PETM terrestrial CIE is at least 5 ‰ smaller than expected based on extrapolation of the scaling relationship established

  14. AMS-{sup 14}C measurements for the carbonate platform of the offshore Campos Basin, Rio de Janeiro State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Coimbra, Melayne M. E-mail: melayne@onda.com.br; Barbosa, Catia F.; Soares-Gomes, Abilio; Silva, Cleverson G.; Rios-Netto, Aristoteles; Mueller, Ken A

    2000-10-01

    As part of our accelerator mass spectrometry (AMS) program in Brazil we prepared and measured some red algae carbonate crust samples from Campos Basin, Rio de Janeiro, Brazil. The measurements were performed at Purdue Rare Isotope Measurement Laboratory (PRIME Lab), Purdue University, IN, USA. This carbonate material is interlaminated with foraminiferal lime mud reflecting recurrent intervals of carbonate development, which might be linked to outer-shelf oceanographic circulation.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

    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.

  17. Subsurface images of the northern Newark basin, New York, USA and their implications for carbon sequestration

    Science.gov (United States)

    Olsen, P. E.; Withjack, M. O.; Schlische, R. W.; Goldberg, D.; Kent, D. V.; Tamulonis, K.; Couëslan, M.; Collins, D. J.

    2011-12-01

    The Triassic-Jurassic Newark rift, a large onshore sedimentary basin close to northeast US metropolitan areas, may have potential for safe geological storage of CO2 in a suitably deep formation overlain by appropriate confining units. Filled with continental synrift sedimentary rocks and CAMP (Central Atlantic Magmatic Province) basaltic intrusions and flows, the basin is bounded on the NW by the NE-striking, SE-dipping Ramapo fault. Funded by the Department of Energy's (DOE) National Energy Technology Laboratory's (NETL) Carbon Sequestration Program's portion of the American Recovery and Reinvestment Act of 2009 (ARRA) and NYSERDA, the TriCarb Consortium for Carbon Sequestration acquired two seismic-reflection profiles in Rockland County, NY that were processed to obtain depth-migrated images of the basin's subsurface geometry. The E-trending dip profile crosses most of the basin, while the shorter N-trending profile provides a strike-view. Five seismic facies are present: (1) shallow continuous, closely spaced, W-dipping reflections suggestive of lacustrine deposits; (2) short, non-coherent reflections suggestive of conglomeritic fluvial strata; (3) high-amplitude parallel reflections, locally exhibiting reverse separation, suggestive of prerift early Paleozoic strata Cambro-Ordovician carbonates; (4) a facies at the bottom of both lines and the western end of the ESE-trending line that lacks reflections, suggestive of prerift metamorphic rocks such as Precambrian gneiss, and/or highly deformed Taconic (Ordovician) phyllites; and (5) a seismically transparent band commonly bounded by high-amplitude reflections that cuts across the stratigraphy of facies 1-3, suggestive of a scoop-shaped intrusive diabase sheet that projects to the surface to outcrops of the CAMP-related Palisade sill. Basin geometry is well-imaged conforming to a deeply eroded half graben. Reflections of facies 3 are truncated by facies 2 marking the angular pre-rift unconformity. Distinct

  18. Characterization of Dissolved Organic Carbon in Deep Groundwater from the Witwatersrand Basin

    Science.gov (United States)

    Pullin, M. J.; Hendrickson, S.; Simon, P.; Sherwood Lollar, B.; Wilkie, K.; Onstott, T. C.; Washton, N.; Clewett, C.

    2013-12-01

    This work describes the isolation, fractionation, and chemical analysis of dissolved organic carbon (DOC) in deep groundwater in the Witwatersrand Basin, South Africa. The groundwater was accessed through mining boreholes in gold and diamond mine shafts. Filtered water samples were collected and preserved for later analysis. In some cases, the organic carbon was also collected on DAX-8 and XAD-4 adsorption resins in situ and then transported to the surface for removal, clean-up, and lyophilization. Solid state C-13 NMR analysis of that organic carbon was conducted. Organic compounds were also isolated from the water using solid phase extraction cartridges for later analysis by GC-MS. Absorbance, fluorescence, and HPLC analyses was were used to analyze the DOC in the filtered water samples. C-14 and C-13 isotopic analysis of the organic carbon was also conducted. Identifiable components of the DOC include both organic acids and amino acids. However, initial results indicate that the majority of the subsurface DOC is a complex heterogeneous mixture with an average molecular weight of approximately 1000 Da, although this DOC is less complex than that found in soils or surface water. Finally, we will discuss possible sources of the organic carbon and its biogeochemical cycling in the subsurface.

  19. National Assessment of Oil and Gas Project - Williston Basin Province (031) Assessment Units

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is...

  20. National Assessment of Oil and Gas Project - Williston Basin Province (031) Boundary

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS Central Region Energy Team assesses oil and gas resources of the United States. The onshore and State water areas of the United States comprise 71...

  1. Hydrocarbons in carbonate rocks of the Neoproterozoic Alto Paraguay basin, Mato Grosso, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Afonso C.R. [Fundacao Univ. do Amazonas, Manaus (Brazil). Dept. de Geociencias; Kerkis, Alexei; Hidalgo, Renata L. [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias. Programa de Pos-graduacao em Geologia Sedimentar; Riccomini, Claudio; Fairchild, Thomas R. [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias]. E-mail: acrnogue@usp.br

    2001-09-01

    Full text of publication follows: A singular occurrence of hydrocarbons (bitumen) was found in Neo proterozoic carbonate rocks of the Araras Formation (Alto Paraguay basin) in the Terconi quarry (Mirassol d'Oeste, Mato Grosso, Brazil). The bitumen occurs in a transgressive carbonate succession overlying Varanger tillites, that consists of two facies associations: (1) lagoon complex, with pink parallel-laminated dolomicrites and fenestral stromatolitic biostromite, and (2) tidal-flat complex, represented by terrigenous gray micrites and pseudosparites, with parallel lamination, asymmetric ripple marks, tepee breccia, planar stromatolites and evaporites. When fresh, the bitumen is compact and vitreous, filling fractures, stylolites and dissolution cavities, generally associated with calcite cement and euhedral dolomite crystals. Microscopic examination shows the bitumen filling pores of primary (fenestral) and secondary (moldic and intragranular) origins. As the first record of hydrocarbon in Neoproterozoic rocks of the Paraguay Belt, this occurrence opens a new perspective for the evaluation of oil potential in Precambrian rocks of Central Brazil. (author)

  2. Impact of Permeability and Mineralization on an Injected Carbon Dioxide Plume in the South Georgia Rift Basin.

    Science.gov (United States)

    Alshammari, A.; Brantley, D.; Knapp, C. C.; Lakshmi, V.

    2016-12-01

    We will study the injection of one million tons per year of super critical phase carbon dioxide in the South Georgia Rift Basin for a 30-year period followed by a 100-year shut-in. We will determine the fault leakage coefficient corresponding to a logarithmic range of subsurface permeability and the mineralization of the injected carbon dioxide. This will help to predict the migration patterns of the sequestered carbon dioxide in the subsurface. These simulations for carbon dioxide flow and mineralization rate and the volume of mineral trapping will use the Computer Modeling Group™ (CMG) software. The simulations will extend to several decades to determine the end products of the system. The South Georgia Rift Basin is located in the Southeastern portion of United States and has been the location for recent studies of carbon dioxide sequestration.

  3. Stable carbon isotopic composition of light hydrocarbons and n-alkanes of condensates in the Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Shipeng Huang

    2017-06-01

    Full Text Available The carbon isotope ratios of individual light hydrocarbons and the n-alkanes of twenty-one condensates from the Tarim Basin, as well as 47 condensates and oils from other petroliferous basins (Ordos Basin, Sichuan Basin, Turpan-Harmi Basin, Qiongdongnan Basin, Beibu Gulf Basin and Bohai Bay Basin in China, were analyzed. We investigated the oil–oil correlation, the effects of gas washing and maturity, as well as the distinguishing parameters of humic and sapropelic condensates, and have come to the following conclusion. The carbon isotopic patterns of condensates and oils in the Ordovician strata of Tarim Basin are very similar, indicating they originate from the same type of source rocks. The condensates from Dawanqi oil field and Yinan 2, as well as Ti'ergen and Yitikelike gas fields, have similar carbon isotopic patterns. Thus, they probably have originated from the same terrestrial Jurassic source rock. The carbon isotopic patterns of the condensates from the Dabei, Kela 2, and Keshen gas fields are also similar, indicating they are of the same oil family and sourced from the Triassic and Jurassic terrestrial source rock. The carbon isotopic ratios of 2-MP, 3-MP, 3-MH, and nC5-8 are much more susceptible to maturity level than other light hydrocarbons. Gas washing has minor effects on the δ13C compositions of individual light hydrocarbons and n-alkanes, although it causes  −25‰, δ13CCH > −24‰, δ13CMCH > −24‰, δ13Cbenzene > −25‰, and δ13Ctoluene > −24‰, whereas sapropelic condensates mainly have δ13CMCP < −26‰, δ13CCH < −26‰, δ13CMCH < −24‰, δ13Cbenzene < −25‰ and δ13Ctoluene < −24‰. Moreover, the mixing humic and sapropelic condensates usually show intermediate values. Keywords: Carbon isotope ratio, Humic condensate, Sapropelic condensate, Oil

  4. Anatomy of a 2nd-order unconformity: stratigraphy and facies of the Bakken formation during basin realignment

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Orion; Canter, Lyn; Sonnenfeld, Mark; Williams, Mark [Whiting Oil and Gas Corp., Denver, CO (United States)

    2011-07-01

    Because classic Laramide compressional structures are relatively rare, the Williston Basin is often considered as structurally simple, but because of the presence of numerous sub-basins, simplistic lithofacies generalization is impossible, and detailed facies mapping is necessary to unravel Middle Bakken paleogeography. The unconformity above the Devonian Three Forks is explained by the infilling and destruction of the Devonian Elk Point basin, prepares the Bakken system, and introduces a Mississippian Williston Basin with a very different configuration. Black shales are too often considered as deposits that can only be found in deep water, but to a very different conclusion must be drawn after a review of stratigraphic geometry and facies successions. The whole Bakken is a 2nd-order lowstand to transgressive systems tract lying below the basal Lodgepole, which represents an interval of maximal flooding. This lowstand to transgressive stratigraphic context explains why the sedimentary process and provenance shows high aerial variability.

  5. Evolvement rules of basin flood risk under low-carbon mode. Part I: response of soil organic carbon to land use change and its influence on land use planning in the Haihe basin.

    Science.gov (United States)

    Li, Fawen; Wang, Liping; Zhao, Yong

    2017-08-01

    Soil organic carbon (SOC) plays an important role in the global carbon cycle. The aim of this study was to evaluate the response of SOC to land use change and its influence on land use planning in the Haihe basin, and provide planning land use pattern for basin flood risk assessment. Firstly, the areas of different land use types in 1980, 2008, and the planning year (2020) were counted by area statistics function of ArcGIS. Then, the transfer matrixes of land use were produced by spatial overlay analysis function. Lastly, based on the land use maps, soil type map and soil profile database, SOC storage of different land use types in three different periods were calculated. The results showed the patterns of land use have changed a lot from 1980 to 2008, among the 19,835 km2 of grassland was transformed into forestland, which was the largest conversion landscape. And land use conversion brought the SOC storage changes. Total carbon source was 88.83 Tg, and total carbon sink was 85.49 Tg. So, the Haihe basin presented as a carbon source from 1980 to 2008. From 2008 to 2020, the changes of forestland and grassland are the biggest in Haihe basin, which cause the SOC pool change from a carbon source to a carbon sink. SOC storage will increase from 2420.5 Tg in 2008 to 2495.5 Tg in 2020. The changing trend is conducive to reducing atmospheric concentrations. Therefore, land use planning in Haihe basin is reasonable and can provide the underlying surface condition for flood risk assessment.

  6. 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.

  7. Basin-Scale Leakage Risks from Geologic Carbon Sequestration: Impact on Carbon Capture and Storage Energy Market Competitiveness

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Catherine; Fitts, Jeffrey; Wilson, Elizabeth; Pollak, Melisa; Bielicki, Jeffrey; Bhatt, Vatsal

    2013-03-13

    This three-year project, performed by Princeton University in partnership with the University of Minnesota and Brookhaven National Laboratory, examined geologic carbon sequestration in regard to CO{sub 2} leakage and potential subsurface liabilities. The research resulted in basin-scale analyses of CO{sub 2} and brine leakage in light of uncertainties in the characteristics of leakage processes, and generated frameworks to monetize the risks of leakage interference with competing subsurface resources. The geographic focus was the Michigan sedimentary basin, for which a 3D topographical model was constructed to represent the hydrostratigraphy. Specifically for Ottawa County, a statistical analysis of the hydraulic properties of underlying sedimentary formations was conducted. For plausible scenarios of injection into the Mt. Simon sandstone, leakage rates were estimated and fluxes into shallow drinking-water aquifers were found to be less than natural analogs of CO{sub 2} fluxes. We developed the Leakage Impact Valuation (LIV) model in which we identified stakeholders and estimated costs associated with leakage events. It was found that costs could be incurred even in the absence of legal action or other subsurface interference because there are substantial costs of finding and fixing the leak and from injection interruption. We developed a model framework called RISCS, which can be used to predict monetized risk of interference with subsurface resources by combining basin-scale leakage predictions with the LIV method. The project has also developed a cost calculator called the Economic and Policy Drivers Module (EPDM), which comprehensively calculates the costs of carbon sequestration and leakage, and can be used to examine major drivers for subsurface leakage liabilities in relation to specific injection scenarios and leakage events. Finally, we examined the competiveness of CCS in the energy market. This analysis, though qualitative, shows that financial

  8. Paleogeographic evolution of carbonate reservoirs: geological and geophysical analysis at the Albian Campos Basin, Brazil

    Science.gov (United States)

    Castillo Vincentelli, Maria Gabriela; Favoreto, Julia; Roemers-Oliveira, Eduardo

    2018-02-01

    An integrated geophysical and geological analysis of a carbonate reservoir can offer an effective method to better understand the paleogeographical evolution and distribution of a geological reservoir and non-reservoir facies. Therefore, we propose a better method for obtaining geological facies from geophysical facies, helping to characterize the permo-porous system of this kind of play. The goal is to determine the main geological phases from a specific hydrocarbon producer (Albian Campos Basin, Brazil). The applied method includes the use of a petrographic and qualitative description from the integrated reservoir with seismic interpretation of an attribute map (energy, root mean square, mean amplitude, maximum negative amplitude, etc), all calculated at the Albian level for each of the five identified phases. The studied carbonate reservoir is approximately 6 km long with a main direction of NE–SW, and it was sub-divided as follows (from bottom to top): (1) the first depositional sequence of the bank was composed mainly of packstone, indicating that the local structure adjacent to the main bank is protected from environmental conditions; (2) characterized by the presence of grainstone developed at the higher structure; (3) the main sequence of the peloidal packstone with mudstones oncoids; (4) corresponds to the oil production of carbonate reservoirs formed by oolitic grainstone deposited at the top of the carbonate bank; at this phase, rising sea levels formed channels that connected the open sea shelf with the restricted circulation shelf; and (5) mudstone and wackestone represent the system’s flooding phase.

  9. Impact of basin burial and exhumation on Jurassic carbonates diagenesis on both sides of a thick clay barrier (Paris Basin, NE France).

    OpenAIRE

    Carpentier, Cédric; Brigaud, Benjamin; Blaise, Thomas; Vincent, Benoît; Durlet, Christophe; Boulvais, Philippe; PAGEL, Maurice; Hibsch, Christian; Yven, Béatrice; Lach, Philippe; Cathelineau, Michel; Boiron, Marie-Christine; Landrein, Philippe; Buschaert, Stéphane

    2014-01-01

    27 pages; International audience; Several diagenetic models have been proposed for Middle and Upper Jurassic carbonates of the eastern Paris Basin. The paragenetic sequences are compared in both aquifers to propose a diagenetic model for the Middle and Late Jurassic deposits as a whole. Petrographic (optical and cathodoluminescence microscopy), structural (fracture orientations) and geochemical (δ18O, δ13C, REE) studies were conducted to characterize diagenetic cements, with a focus on blocky...

  10. The stable isotopic and chemical composition of pedogenic carbonate in the Minusinsk Basin, South Siberia

    Science.gov (United States)

    Vasilchuk, Jessica; Ivanova, Elena; Krechetov, Pavel; Litvinskiy, Vladimir; Budantseva, Nadine; Chizhova, Julia; Vasil'chuk, Yurij

    2017-04-01

    Stable isotope composition of carbonate neoformations can be used as a proxy for the reconstructons of environmental conditions of the past. Carbonate coatings on coarse rock framents are studied in order to indicate the climatic conditions and predominant vegetation under which they were formed. Such coatings commonly occur in different types of soils and paleosols of South Siberian intermountain basins mainly in relatively dry modern conditions. The purpose of the research is to characterize the isotopic composition and chemical composition of carbonate pedofeatures in soils of Minusink Hollow and estimate its correlation with defferent factors. The samples of pedogenic carbonates, vegetation, carbonate parent material, soil water and precipitation water were analyzed using the Delta-V mass spectrometer with options of a gas bench and element analyser. The soils we studied are mainly Kastanozems that are poorly moisturized; therefore, soil pore water was extracted by ethanol. Minor and major elements content was also measured by ICP-MS. Carbonates mostly contain calcuim (37-45%) and highly enriched in Pb, Tl and Ba. Oxygen and carbon isotopic composition of pedogenic carbonates was analyzed in 3 key sites. Kazanovka Khakass state national reserve, Hankul salt lake, region of Sayanogorsk aluminum smelter. Vegetation photosynthetic pathway in the region is mainly C3. δ18O values of carbonate coatings in soils of Kazanovka vary in a range from -7.49 to -10.5‰ (vs V-PDB). The lowest values corresponds the coatings found between two buried mid-Holocene soil horizons. That may indicate cooler conditions of late Holocene than nowadays. In Sayanogorsk carbonates' δ18O values' range is -8.3...-11.1‰ and near the Hankul Lake is -9.0...-10.2‰ all ranges are quite similar and may indicate close conditions of pendants formation. δ13C values of carbonate coatings in Kazanovka vary from -2.5 to -6.7‰, the highest values correspond to the soils of Askiz and Syglygkug

  11. Sedimentary mode and reservoir distribution of the Cambrian carbonate & evaporate paragenesis system in the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Anna Xu

    2016-11-01

    Full Text Available The Cambrian carbonate & evaporite paragenesis system in the Sichuan Basin is made up of the Longwangmiao, Gaotai and Xixiangchi Fms. So far, great breakthrough has been made only in the Longwangmiao Fm instead of the latter two, and the Anyue Gasfield was discovered in the center of this basin. In this paper, therefore, the Cambrian carbonate & evaporite paragenesis system in the Sichuan Basin was analyzed in terms of its structural–sedimentary setting, sequence stratigraphic framework, sedimentary facies and the distribution of evaporites by using various geologic, logging and seismic data. Then, the geological model of sedimentary facies was established and the distribution range of favorable reservoirs was predicted. Based on these studies, the following results are obtained. Firstly, the palaeotectonic framework is characterized by the style of “one depression between two uplifts” in the setting of a large SE dipping slope, and the stratigraphic filling is in the structure of “onlapping at the bottom and truncation at the top” which is thin in the west and thick in the east. Secondly, three third-order sequence cycles which, on the whole, become shallow upward are developed from bottom to top, and gypsum-salt rocks are mainly located at the high system tract (HST of third-order sequences and concentrated in the Wanzhou–Yibin sag. Thirdly, the geological model of sedimentary facies is composed of three major sedimentary structural layers from bottom to top, namely the evaporative carbonate ramp, the evaporative diamictic restricted platform and the evaporative restricted platform. The sedimentary environment changes from the open to the closed and the penesaline for a long time, and then back to the open. The distribution of shoals changes from the pattern of “dual banks” in a large area to more scattered shoals and banded shoals, while the evaporative lagoon and tidal flat shrink. Fourthly, the reservoir distribution is

  12. Origin of red pelagic carbonates as an interplay of global climate and local basin factors: Insight from the Lower Devonian of the Prague Basin, Czech Republic

    Science.gov (United States)

    Bábek, Ondřej; Faměra, Martin; Hladil, Jindřich; Kapusta, Jaroslav; Weinerová, Hedvika; Šimíček, Daniel; Slavík, Ladislav; Ďurišová, Jana

    2018-02-01

    Red pelagic sediments are relatively common in the Phanerozoic. They are often interpreted as products of sea-bottom oxidation during greenhouse climate showing a conspicuous alternation with black shales and thus carrying important palaeoceanographic information. The Lower Devonian (Pragian) carbonate strata of the Prague Basin, Czech Republic (Praha Formation) contain a marked band of red pelagic carbonate, up to 15 m thick, which can be correlated for several tens of km. We investigated seven sections (17 to 255 m thick) of the Prague Basin using the methods of facies analysis, outcrop gamma-ray logging, diffuse reflectance spectroscopy, optical microscopy, element geochemistry, magneto-mineralogy and electron microprobe analysis. The aim was to find the mineral carriers of the red colour, investigate the stratigraphic context of the red carbonates and evaluate the local and global prerequisites for their formation. The red pigmentation represents enrichment by hematite with respect to goethite. Approximately 31% of the total reflectance falling in the red colour band represents a threshold for red coloration. The red pigmentation is carried by submicronic hematite dispersed in argillaceous pelagic calcilutite and/or inside skeletal allochems. Gamma-ray log correlation indicates that the red carbonate band developed in stratigraphic levels with low sedimentation rates, typically from 1 to 7.1 mm/kyr, which are comparable to the Mesozoic Rosso Ammonitico facies. The red beds and the whole Praha Formation (Pragian to early Emsian) are characterized by low TOC values (successions of the Prague Basin indicate that switching between two greenhouse climatic modes, colder oligotropic and warmer mesotrophic, may have been responsible for the alternation of red and grey carbonate strata, respectively.

  13. Ultramorphological features of the egg of Telmatoscopus albipunctatus (Williston (Diptera, Psychodidae

    Directory of Open Access Journals (Sweden)

    Thalita Rocha

    2011-06-01

    Full Text Available Ultramorphological features of the egg of Telmatoscopus albipunctatus (Williston (Diptera, Psychodidae. Psychodidae flies, also known as sewage, sand and filter flies are important for medical and veterinary purposes. General information about life cycle and adult habits is available, but few species are known about the egg morphology. Therefore, in this study, the egg ultramorphology of Telmatoscopus albipunctatus (Williston, 1893 was analyzed by scanning electron microscopy to describe its structure, generating data for further comparison between different fly species and genera. General aspects of T. albipunctatus egg are similar to other Psychodidae; egg measuring approximately 0.4 mm in length and 0.1 mm in width. However, based on the continuous and discontinuous longitudinal ridge sculptures observed on the exochorion, which can be species-specific, we can infer that T. albipunctatus eggs can survive under dry or moist conditions, making their control much more difficult. Our data emphasize the advantages of the electron microscope approach in the study of the exochorion patterns. Eggshell morphology of T. albipunctatus can be used as basis for further studies and as a tool to compare different species of Psychodidae flies.Aspectos ultramorfológicos do ovo de Telmatoscopus albipunctatus (Williston (Diptera, Psychodidae. As moscas da família Psychodidae, também conhecidas como moscas de banheiro, são de importância médica e veterinária. Informações gerais sobre ciclo de vida e hábitos do adulto são facilmente encontradas, mas pouco se sabe sobre a morfologia do ovo. Dessa forma, neste estudo, a ultramofologia do ovo de Telmatoscopus albipunctatus (Williston, 1893 foi analisada por microscopia eletrônica de varredura com o objetivo de descrever sua estrutura, provendo importantes dados para futuras comparações entre moscas de diferentes espécies e gêneros. O aspecto geral do ovo de T. albipunctatus é similar a outros

  14. Occurrence and origin of carbon dioxide in the Fushan Depression, Beibuwan Basin, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meijun; Wang, Tieguan [Key Laboratory for Hydrocarbon Accumulation Mechanism of the Chinese Ministry of Education, Earth Sciences and Geoinformatics School, China University of Petroleum, Beijing 102200 (China); Liu, Ju; Wu, Weiqiang; Gao, Lihui [Petro China Southern Oil Exploration and Development Company, Guangzhou 510640 (China); Lu, Hong [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2008-06-15

    Natural gases produced from the Fushan Depression, Beibuwan Basin, South China Sea are generally rich in carbon dioxide. The {delta}{sup 13}C values of methane in these gases are within the range of -41.18 permille to -47.00 permille. This, together with the linearity of the {delta}{sup 13}C values of methane to butane in the ''natural gas plots,'' indicates that the hydrocarbon gases are of organic origin. The {delta}{sup 13}C{sub CO2} values of these gases are in the range of -5.1 permille to -7.5 permille, suggesting an inorganic origin. A dominant mantle source for the CO{sub 2} in these gases was determined on the basis of a simple binary mixing model using the {delta}{sup 13}C{sub CO2} values and {sup 3}He/{sup 4}He ratios of associated helium in these gases. The primary geological controls on the occurrence of CO{sub 2} rich gas accumulations in the Fushan Depression are discussed following a comparison with other sedimentary basins in the region. (author)

  15. Carbon Capture and Storage in the Permian Basin, a Regional Technology Transfer and Training Program

    Energy Technology Data Exchange (ETDEWEB)

    Rychel, Dwight [Petroleum Tech Transfer Council, Oak Hill, VA (United States)

    2013-09-30

    The Permian Basin Carbon Capture, Utilization and Storage (CCUS) Training Center was one of seven regional centers formed in 2009 under the American Recovery and Reinvestment Act of 2009 and managed by the Department of Energy. Based in the Permian Basin, it is focused on the utilization of CO2 Enhanced Oil Recovery (EOR) projects for the long term storage of CO2 while producing a domestic oil and revenue stream. It delivers training to students, oil and gas professionals, regulators, environmental and academia through a robust web site, newsletter, tech alerts, webinars, self-paced online courses, one day workshops, and two day high level forums. While course material prominently features all aspects of the capture, transportation and EOR utilization of CO2, the audience focus is represented by its high level forums where selected graduate students with an interest in CCUS interact with Industry experts and in-house workshops for the regulatory community.

  16. Distribution and origin of suspended matter and organic carbon pools in the Tana River Basin, Kenya

    Directory of Open Access Journals (Sweden)

    F. Tamooh

    2012-08-01

    Full Text Available We studied patterns in organic carbon pools and their origin in the Tana River Basin (Kenya, in February 2008 (dry season, September–November 2009 (wet season, and June–July 2010 (end of wet season, covering the full continuum from headwater streams to lowland mainstream sites. A consistent downstream increase in total suspended matter (TSM, 0.6 to 7058 mg l−1 and particulate organic carbon (POC, 0.23 to 119.8 mg l−1 was observed during all three sampling campaigns, particularly pronounced below 1000 m above sea level, indicating that most particulate matter exported towards the coastal zone originated from the mid and low altitude zones rather than from headwater regions. This indicates that the cascade of hydroelectrical reservoirs act as an extremely efficient particle trap. Although 7Be / 210Pbxs ratios/age of suspended sediment do not show clear seasonal variation, the gradual downstream increase of suspended matter during end of wet season suggests its origin is caused by inputs of older sediments from bank erosion and/or river sediment resuspension. During wet season, higher TSM concentrations correspond with relatively young suspended matter, suggesting a contribution from recently eroded material. With the exception of reservoir waters, POC was predominantly of terrestrial origin as indicated by generally high POC : chlorophyll a (POC : Chl a ratios (up to ~41 000. Stable isotope signatures of POC (δ13CPOC ranged between −32 and −20‰ and increased downstream, reflecting an increasing contribution of C4-derived carbon in combination with an expected shift in δ13C for C3 vegetation towards the more semi-arid lowlands. δ13C values in sediments from the main reservoir (−19.5 to −15.7‰ were higher than those found in any of the riverine samples, indicating selective retention of particles associated with C4

  17. Carbon and nitrogen contents in Desert Plants and Soil in the Yanqi basin of Northwestern China

    Science.gov (United States)

    Zhang, J.; Wang, X.; Wang, J.

    2011-12-01

    Carbon and nitrogen are two main elements in plant-soil systems. Here, we present a study of carbon and nitrogen contents in several typical desert plants and underlying soil, which was conducted in Yanqi basin, Xinjiang province of China. Our results show that carbon (C) content is around 30% in both aboveground tissues and belowground roots. Nitrogen (N) content in desert plants has a range of 0.5%-3.5%, and the aboveground tissue has higher nitrogen content (~2%) than the belowground root (~1%). As a result, the belowground root has higher C/N ratio (~35) than the aboveground tissue (~25). Especially, the C/N values in belowground roots are twice as much as their aboveground tissues in Acroption repens, Tamarix ramosissima Ledeb. and Halostachys caspica. In desert soils, the contents of soil organic carbon (SOC), total nitrogen (TN) with depth 0-50cm are range of 12.5-4.6 and 3.2-1.4 g/kg, respectively, different . As expected, the SOC and TN contents are declined with the depth increase. Meanwhile, our result indicated the soil TN is followed the SOC dynamic, as both elements are bond into the organic compounds. However, unlike the C/N ratios in aboveground tissue and roots, there is no significant difference of C/N ratios (2.95-3.46) in the soils within the 0-50 cm depth. The results inferred that in the desert plant C mainly storage in roots, but the C, N allocation between desert plant and soil has no significantly related.

  18. Carbon isotopes of Middle-Lower Jurassic coal-derived alkane gases from the major basins of northwestern China

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Jinxing [PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083 (China); Department of Earth Science, Zhejiang University, Hangzhou 310027 (China); Faculty of Natural Resources and Information Technology, University of Petroleum, Beijing, 102200 (China); Zou, Caineng; Ni, Yunyan; Liu, Quanyou; Yang, Chun [PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083 (China); Li, Jian; Hu, Guoyi [PetroChina Research Institute of Petroleum Exploration and Development-Langfang Branch, Hebei 065007 (China); Zhang, Xiaobao [Lanzhou Institute of Geology, CAS, Lanzhou 730000 (China); Hu, Anping [Department of Earth Science, Zhejiang University, Hangzhou 310027 (China)

    2009-11-01

    Coal-derived hydrocarbons from Middle-Lower Jurassic coal-bearing strata in northwestern China are distributed in the Tarim, Junggar, Qaidam, and Turpan-Harmi basins. The former three basins are dominated by coal-derived gas fields, distributed in Cretaceous and Tertiary strata. Turpan-Harmi basin is characterized by coal-derived oil fields which occur in the coal measures. Based on analysis of gas components and carbon isotopic compositions from these basins, three conclusions are drawn in this contribution: 1) Alkane gases with reservoirs of coal measures have no carbon isotopic reversal, whereas alkane gases with reservoirs not of coal measures the extent of carbon isotopic reversal increases with increasing maturity; 2) Coal-derived alkane gases with high {delta}{sup 13}C values are found in the Tarim and Qaidam basins ({delta}{sup 13}C{sub 1}: - 19.0 to - 29.9 permille; {delta}{sup 13}C{sub 2}: - 18.8 to - 27.1 permille), and those with lowest {delta}{sup 13}C values occur in the Turpan-Harmi and Junggar basins ({delta}{sup 13}C{sub 1}: - 40.1 to - 44.0 permille; {delta}{sup 13}C{sub 2}: - 24.7 to - 27.9 permille); and 3) Individual specific carbon isotopic compositions of light hydrocarbons (C{sub 5-8}) in the coal-derived gases are lower than those in the oil-associated gases. The discovered carbon isotopic reversal of coal-derived gases is caused by isotopic fractionation during migration and secondary alteration. The high and low carbon isotopic values of coal-derived gases in China may have some significance on global natural gas research, especially the low carbon isotope value of methane may provide some information for early thermogenic gases. Coal-derived methane typically has much heavier {delta}{sup 13}C than that of oil-associated methane, and this can be used for gas-source rock correlation. The heavy carbon isotope of coal-derived ethane is a common phenomenon in China and it shed lights on the discrimination of gas origin. Since most giant gas

  19. Transport and Retention of Nitrogen, Phosphorus and Carbon in North America’s Largest River Swamp Basin, the Atchafalaya River Basin

    Directory of Open Access Journals (Sweden)

    Y. Jun Xu

    2013-04-01

    Full Text Available Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004 river discharge and water quality records from an upriver and a downriver location of the Atchafalaya River to quantify the inflow, outflow, and inflow–outflow mass balance of total Kjeldahl nitrogen (TKN = organic nitrogen + ammonia nitrogen, nitrate + nitrite nitrogen (NO3 + NO2, total phosphorous (TP, and total organic carbon (TOC through the largest river swamp basin in North America. The study found that, over the past 27 years, the Atchafalaya River Basin (ARB acted as a significant sink for TKN (annual retention: 24%, TP (41%, and TOC (12%, but a source for NO3 + NO2 nitrogen (6%. On an annual basis, ARB retained 48,500 t TKN, 16,900 t TP, and 167,100 t TOC from the river water. The retention rates were closely and positively related to the river discharge with highs during the winter and spring and lows in the late summer. The higher NO3 + NO2 mass outflow occurred throughout spring and summer, indicating an active role of biological processes on nitrogen as water and air temperatures in the basin rise.

  20. An Assessment of Geological Carbon Sequestration Options in the Illinois Basin

    Energy Technology Data Exchange (ETDEWEB)

    Robert Finley

    2005-09-30

    The Midwest Geological Sequestration Consortium (MGSC) has investigated the options for geological carbon dioxide (CO{sub 2}) sequestration in the 155,400-km{sup 2} (60,000-mi{sup 2}) Illinois Basin. Within the Basin, underlying most of Illinois, western Indiana, and western Kentucky, are relatively deeper and/or thinner coal resources, numerous mature oil fields, and deep salt-water-bearing reservoirs that are potentially capable of storing CO{sub 2}. The objective of this Assessment was to determine the technical and economic feasibility of using these geological sinks for long-term storage to avoid atmospheric release of CO{sub 2} from fossil fuel combustion and thereby avoid the potential for adverse climate change. The MGSC is a consortium of the geological surveys of Illinois, Indiana, and Kentucky joined by six private corporations, five professional business associations, one interstate compact, two university researchers, two Illinois state agencies, and two consultants. The purpose of the Consortium is to assess carbon capture, transportation, and storage processes and their costs and viability in the three-state Illinois Basin region. The Illinois State Geological Survey serves as Lead Technical Contractor for the Consortium. The Illinois Basin region has annual emissions from stationary anthropogenic sources exceeding 276 million metric tonnes (304 million tons) of CO{sub 2} (>70 million tonnes (77 million tons) carbon equivalent), primarily from coal-fired electric generation facilities, some of which burn almost 4.5 million tonnes (5 million tons) of coal per year. Assessing the options for capture, transportation, and storage of the CO{sub 2} emissions within the region has been a 12-task, 2-year process that has assessed 3,600 million tonnes (3,968 million tons) of storage capacity in coal seams, 140 to 440 million tonnes (154 to 485 million tons) of capacity in mature oil reservoirs, 7,800 million tonnes (8,598 million tons) of capacity in saline

  1. Cross-fault pressure depletion, Zechstein carbonate reservoir, Weser-Ems area, Northern German Gas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Corona, F.V.; Brauckmann, F.; Beckmann, H.; Gobi, A.; Grassmann, S.; Neble, J.; Roettgen, K. [ExxonMobil Production Deutschland GmbH (EMPG), Hannover (Germany)

    2013-08-01

    A cross-fault pressure depletion study in Upper Permian Zechstein Ca2 carbonate reservoir was undertaken in the Weser-Ems area of the Northern German Gas Basin. The primary objectives are to develop a practical workflow to define cross-fault pressures scenarios for Zechstein Ca2 reservoir drillwells, to determine the key factors of cross-fault pressure behavior in this platform carbonate reservoir, and to translate the observed cross-fault pressure depletion to fault transmissibility for reservoir simulation models. Analysis of Zechstein Ca2 cross-fault pressures indicates that most Zechstein-cutting faults appear to act as fluid-flow baffles with some local occurrences of fault seal. Moreover, there appears to be distinct cross-fault baffling or pressure depletion trends that may be related to the extent of the separating fault or fault system, degree of reservoir flow-path tortuosity, and quality of reservoir juxtaposition. Based on the above observations, a three-part workflow was developed consisting of (1) careful interpretation and mapping of faults and fault networks, (2) analysis of reservoir juxtaposition and reservoir juxtaposition quality, and (3) application of the observed cross-fault pressure depletion trends. This approach is field-analog based, is practical, and is being used currently to provide reliable and supportable pressure prediction scenarios for subsequent Zechstein fault-bounded drill-well opportunities.

  2. Sulphur and carbon isotopic composition of power supply coals in the Pannonian Basin, Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Hamor-Vido, Maria [Eoetvoes Lorand Geophysical Institute of Hungary, H-1145 Budapest, Kolumbusz st. 17-23 (Hungary); Hamor, Tamas [Hungarian Geological Survey, H-1143 Budapest, Stefania st. 14 (Hungary)

    2007-08-01

    The present work is an attempt to establish the stable isotope database for Mesozoic to Tertiary coals from the Pannonian Basin, Hungary. Maceral composition, proximate analysis, sulphur form, sulphur isotopes (organic and pyritic), and carbon isotopes were determined. This database supports the assessment of the environmental risks associated with energy generation, the characterization of the formation and the distribution of sulphur in the coals used. The maceral composition, the sulphur composition, the C, S isotopic signatures, and some of the geological evidences published earlier show that the majority of these coals were deposited in freshwater and brackish water environments, despite the relatively high average sulphur content. However, the Upper Cretaceous, Eocene, and Lower Miocene formations also contain coal seams of marine origin, as indicated by their maceral composition and sulphur and carbon chemistry. The majority of the sulphur in these coals occurs in the organic form. All studied sulphur phases are relatively rich in {sup 34}S isotopes ({delta}{sup 34}S{sub organic} = + 12.74 permille, {delta}{sup 34}S{sub pyrite} = + 10.06 permille, on average). This indicates that marine bacterial sulphate reduction played a minor role in their formation, in the sense that isotopic fractionation was limited. It seems that the interstitial spaces of the peat closed rapidly during early diagenesis due to a regime of high depositional rate, leading to a relative enrichment of the heavy sulphur isotopes. (author)

  3. Distribution and landscape controls of organic layer thickness and carbon within the Alaskan Yukon River Basin

    Science.gov (United States)

    Pastick, Neal J.; Rigge, Matthew B.; Wylie, Bruce K.; Jorgenson, M. Torre; Rose, Joshua R.; Johnson, Kristofer D.; Ji, Lei

    2014-01-01

    Understanding of the organic layer thickness (OLT) and organic layer carbon (OLC) stocks in subarctic ecosystems is critical due to their importance in the global carbon cycle. Moreover, post-fire OLT provides an indicator of long-term successional trajectories and permafrost susceptibility to thaw. To these ends, we 1) mapped OLT and associated uncertainty at 30 m resolution in the Yukon River Basin (YRB), Alaska, employing decision tree models linking remotely sensed imagery with field and ancillary data, 2) converted OLT to OLC using a non-linear regression, 3) evaluate landscape controls on OLT and OLC, and 4) quantified the post-fire recovery of OLT and OLC. Areas of shallow (2 = 0.68; OLC: R2 = 0.66), where an average of 16 cm OLT and 5.3 kg/m2 OLC were consumed by fires. Strong predictors of OLT included climate, topography, near-surface permafrost distributions, soil wetness, and spectral information. Our modeling approach enabled us to produce regional maps of OLT and OLC, which will be useful in understanding risks and feedbacks associated with fires and climate feedbacks.

  4. Spatially Explicit Modeling of Grazing Effect on Soil Organic Carbon Change in the Green River Basin, Wyoming

    Science.gov (United States)

    Li, Z.; Liu, S.; Tan, Z.

    2007-12-01

    Proper grazing can improve ecosystem production and enhance carbon sequestration, while overgrazing can lead to net emission of carbon into the atmosphere. It is challenging to quantify the impacts of grazing at a regional scale owing to the spatial and temporal changes of biophysical settings and land management practices. In this study, we quantified and evaluated impacts of grazing intensity on the dynamics of soil organic carbon (SOC) across the Green River Basin in southwestern Wyoming using a biogeochemical model (EDCM--erosion-deposition-carbon model) and remotely sensed data. We simulated responses of ecosystem carbon stocks (including SOC) and fluxes to various grazing scenarios. Results based on these simulations indicate that: (1) sagebrush-dominated shrublands accumulated less soil carbon than did grass-dominated area; (2) grazing could lead to a greater decrease in production and SOC in the shrubland than in the grassland under the same intensity and (3) a grazing intensity of 0.03 animal units per hectare could reduce SOC at a rate of 3.1 gC/m2/yr in shrublands, but SOC changed little in grasslands during 30 years of simulated responses. Our model simulations also show that conversion of shrubland to grassland can enhance soil carbon sequestration in the Green River Basin.

  5. Hydrothermally fluoritized Ordovician carbonates as reservoir rocks in the Tazhong area, central Tarim Basin, NW China

    Energy Technology Data Exchange (ETDEWEB)

    Zhijun Jin; Dongya Zhu [Exploration and Production Institute, Beijing (China); Xuefeng Zhang; Wenxuan Hu; Yucai Song [Nanjing University (China). Dept. of Earth Sciences

    2006-01-15

    Reservoir rocks at the Tazhong 45 oil pool, central Tarim Basin, consist of fluoritized carbonate strata of Middle-Late Ordovician age. Petrological observations indicate that the fluorite replaces calcite. Several other hydrothermal minerals accompany the fluorite and include pyrite, quartz, sphalerite and chlorite. Two generations of fluid inclusions are present in the fluorite. Homogenization temperatures (Th) for primary inclusions are mostly between 260{sup o}C and 310{sup o}C, representing the temperature of the hydrothermal fluid responsible for fluorite precipitation. Th for secondary inclusions range from 100{sup o}C to 130{sup o}C, and they represent the hydrocarbon charging temperature as shown by the presence of hydrocarbons trapped in some secondary inclusions. The mineral assemblage and the homogenization temperatures of primary fluid inclusions indicate that the precipitation of fluorite is related to hydrothermal activity in the Tazhong area. Strontium isotope analyses imply that the hydrothermal fluids responsible for fluorite precipitation are related to late-stage magmatic activity, and felsic magmas were generated by mixing of mafic magma and crustal materials during the Permian. Theoretical calculations show that the molecular volume of a carbonate rock decreases by 33.5% when calcite is replaced by fluorite, and the volume shrinkage can greatly enhance reservoir porosity by the formation of abundant intercrystalline pores. Fluoritization has thus greatly enhanced the reservoir quality of Ordovician carbonates in the Tazhong 45 area, so that the fluorite and limestone host rocks in the area have become an efficient hydrocarbon reservoir. According to the modelled burial and thermal history of the Tazhong 45 well, and the homogenization temperatures of secondary fluid inclusions in the fluorite, hydrocarbon charging at the Tazhong 45 reservoir took place in the Tertiary. (author)

  6. Seasonal and spatial contrasts of sedimentary organic carbon in floodplain lakes of the central Amazon basin.

    Science.gov (United States)

    Sobrinho, Rodrigo; Kim, Jung-Hyun; Abril, Gwenaël; Zell, Claudia; Moreira-Turcq, Patricia; Mortillaro, Jean-Michel; Meziane, Tarik; Damsté, Jaap; Bernardes, Marcelo

    2014-05-01

    Three-quarters of the area of flooded land in the world are temporary wetlands (Downing, 2009), which play a significant role in the global carbon cycle(Einsele et al., 2001; Cole et al., 2007; Battin et al., 2009; Abril et al., 2013). Previous studies of the Amazonian floodplain lakes (várzeas), one important compartment of wetlands, showed that the sedimentation of organic carbon (OC) in the floodplain lakes is strongly linked to the periodical floods and to the biogeography from upstream to downstream(Victoria et al., 1992; Martinelli et al., 2003). However, the main sources of sedimentary OC remain uncertain. Hence, the study of the sources of OC buried in floodplain lake sediments can enhance our understanding of the carbon balance of the Amazon ecosystems. In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Miratuba, and Curuai) which have different morphologies, hydrodynamics and vegetation coverage. 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 geochemical tracers such as C:N ratio and stable isotopic composition of organic carbon (δ13COC). These results were compared with lignin-phenol parameters as an indicator of vascular plant detritus (Hedges and Ertel, 1982) and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the soil OC from land to the aquatic settings (Hopmans et al., 2004). Our data showed that during the RW and FW seasons, the concentration of lignin and brGDGTs were higher in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of a mixture of C3 plant detritus and soil OC. However, a downstream increase in C4 plant-derived OC contribution was observed along the gradient of increasingly open waters, i

  7. Formation of methane-related authigenic carbonates in a highly dynamic biogeochemical system in the Krishna–Godavari Basin, Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Kocherla, M.; Teichert, B.M.A.; Pillai, S.; Satyanarayan, M.; Ramamurty, P.B.; Patil, D.J.; Rao, A.N.

    We report the abundant occurrence of authigenic Fe-rich carbonate, high Mg-calcite (HMC) and low Mg-calcite from 11 cores recovered from the Krishna–Godavari Basin (K–G Basin), Bay of Bengal. The cores were collected as part of the Indian gas...

  8. Geological Carbon Sequestration Storage Resource Estimates for the Ordovician St. Peter Sandstone, Illinois and Michigan Basins, USA

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, David; Ellett, Kevin; Leetaru, Hannes

    2014-09-30

    The Cambro-Ordovician strata of the Midwest of the United States is a primary target for potential geological storage of CO2 in deep saline formations. The objective of this project is to develop a comprehensive evaluation of the Cambro-Ordovician strata in the Illinois and Michigan Basins above the basal Mount Simon Sandstone since the Mount Simon is the subject of other investigations including a demonstration-scale injection at the Illinois Basin Decatur Project. The primary reservoir targets investigated in this study are the middle Ordovician St Peter Sandstone and the late Cambrian to early Ordovician Knox Group carbonates. The topic of this report is a regional-scale evaluation of the geologic storage resource potential of the St Peter Sandstone in both the Illinois and Michigan Basins. Multiple deterministic-based approaches were used in conjunction with the probabilistic-based storage efficiency factors published in the DOE methodology to estimate the carbon storage resource of the formation. Extensive data sets of core analyses and wireline logs were compiled to develop the necessary inputs for volumetric calculations. Results demonstrate how the range in uncertainty of storage resource estimates varies as a function of data availability and quality, and the underlying assumptions used in the different approaches. In the simplest approach, storage resource estimates were calculated from mapping the gross thickness of the formation and applying a single estimate of the effective mean porosity of the formation. Results from this approach led to storage resource estimates ranging from 3.3 to 35.1 Gt in the Michigan Basin, and 1.0 to 11.0 Gt in the Illinois Basin at the P10 and P90 probability level, respectively. The second approach involved consideration of the diagenetic history of the formation throughout the two basins and used depth-dependent functions of porosity to derive a more realistic spatially variable model of porosity rather than applying a

  9. Extensive Holocene tropical peat and carbon accumulation within a subsiding intraforeland basin (Pastaza fan and Ucamara floodbasin), Peruvian Amazonia

    Science.gov (United States)

    Lähteenoja, Outi; Räsänen, Matti; Rojas Reátegui, Yully; Del Castillo, Dennis; Oinonen, Markku

    2010-05-01

    Several studies discuss the role of the Amazon Basin in the global carbon cycle, but the existence of extensive tropical peat deposits in lowland Amazonia has been suggested only recently. These up to 5.9 m thick peat deposits documented from a floodplain environment in Western Amazonia have accumulated at high rates (0.94-4.88 mm per year) acting as a strong carbon sink (Lähteenoja et al. 2009). The tectonic environment of Western Amazonia is a foreland belt formed during the uplift of the Andes Mountains as a result of shallow subduction and compressive foreland shortening (Räsänen et al. 1987, Dumont 1996). These foreland basins are characterized by high subsidence rates, up to 4-11 km of sediment deposits as well as river aggradation and avulsions (Räsänen et al. 1987). We studied peat and carbon accumulation in the Pastaza-Marañón intraforeland basin, which consists of the volcanogenic Pastaza alluvial fan and the Ucamara meandering river floodbasin. Together, they form the largest modern tropical system of fluvial aggradation, whose potential to accumulate peat is considerable. In 13 wetland sites detected in Landsat TM satellite images, we measured peat thickness along a transect and collected peat samples for determination of total organic content, carbon content, dry bulk density, AMS radiocarbon age and peat and carbon accumulation rates. According to the results, the Pastaza fan and the Ucamara floodbasin harbor thick peatlands, whose existence has not been previously discussed. All the study sites had either a continuous peat deposit over clastic sediments or a complex stratigraphy of successive layers of clastic sediments, clayey peat and pure peat. Thickness of these heterogeneous deposits varied from 0.20 to 7.5 m. Bulk density, total organic content and carbon content varied from 0.01 to 0.26 g/cm3, from 37 to 99 %, and from 19 to 59 %, respectively. The complex stratigraphies (encountered especially in the Ucamara floodbasin) are obviously

  10. Evapotranspiration units in the Basin and Range carbonate-rock aquifer system, White Pine County, Nevada, and adjacent parts of Nevada and Utah

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Accurate estimates of ground-water discharge are crucial in the development of a water budget for the Basin and Range Carbonate-rock Aquifer System (BARCAS) study...

  11. 1:1,000,000-scale potentiometric contours and control points for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a U.S. Geological Survey (USGS) study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer...

  12. Three-dimensional hydrogeologic framework for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  13. 1:1,000,000-scale hydrographic areas and flow systems for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a U.S. Geological Survey (USGS) study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer...

  14. Bacteria, carbon dioxide and methane measurements in the Cariaco Basin on the continental shelf of Venezuela, April 2001 - January 2002 (NODC Accession 0001078)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bacteria, carbon dioxide and methane measurements were collected using bottle casts in the Cariaco Basin on the continental shelf of Venezuela from 30 April 2001 to...

  15. Pedogenesis and Permafrost Carbon Over the Eboling Ridge in Heihe River Basin, Northwestern China

    Science.gov (United States)

    Mu, C.; Zhang, T.; Cao, B.; Wang, Q.; Peng, X.; Cheng, G.

    2013-12-01

    Based on field permafrost sampling and laboratory analysis, we found that the average storages of soil organic carbon (SOC), total nitrogen (TN) and soil inorganic carbon (SIC) in permafrost soils were much more than that in the active layer on the Eboling Mountain in the upper reach of Heihe River basin, northwestern China. The objective of this study is to better understand the main soil physicochemical parameters influencing C and N dynamics in permafrost regions of northwestern China. Specifically, we investigated the effect of pedogenesis, cryogenic structure and SIC on SOC, TN and water-soluble organic carbon (WSOC) in the permafrost regions. The preliminary results show that SIC is a significant factor influencing carbon flux between atmosphere and terrestrial ecosystem and the distribution patterns of SOC and N. There are high correlation between SIC, SOC and N in permafrost. SOC and SIC can interact with each other, their small change may radically alter the carbon balance. SIC as a major factor will be crucial for developing large scale models evaluating C and N dynamics. High contents of C and N combined with a low vertical variability in each horizon on the Eboling Mountain can be explained by longer duration of pedogenesis and the influence of permafrost. In permafrost regions, the vertical distribution of soil C and N is also influenced by soil cryogenic structure. The high content of WSOC in deep permafrost soils can be explained by the formation of the ground ice causes the WSOC enrichment followed moisture migration. The average WSOC content in permafrost soils was larger than that in the active layer, suggesting that the labile carbon in permafrost soils has higher quality. SIC can reflect the microbial activity indirectly, due to the good negative relationship between SIC, soil pH and C/N ratios in permafrost. Soil pH values were the important factor influencing the distribution of SIC in deep permafrost soils. SIC in permafrost soils was

  16. Carbon isotopic evidence from paleosols for mixed C 3/C 4 vegetation in the Bogota Basin, Colombia

    Science.gov (United States)

    Mora, Germán; Pratt, Lisa M.

    2002-04-01

    Pollen reconstructions in the Bogota basin (Colombia) indicate the expansion of tropical high-altitude grassland (paramo) at the expense of Andean forests during glacial intervals. The carbon isotopic composition (δ 13C) of soil organic matter (SOM) can be a useful indicator of changes in vegetation affecting grasslands because it distinguishes between two groups of grasses (C 3 and C 4) adapted to different ecological environments. Values of SOM δ 13C were determined in four weathering profiles containing both modern (Holocene) soils and paleosols formed during the Last Glacial Stage. These profiles are located along an altitudinal transect in the Bogota basin, extending from 2550 to 3100 m. Values of SOM δ 13C in the topsoil horizons reflect those of the native C 3 vegetation that currently dominates the ecosystems in the Colombian Andes. Although C 4 grasses are currently negligible in the basin, elevated SOM δ 13C values indicative of C 4 plants were found in two Holocene soils. Environmental changes or ancient agricultural activities could explain the increased abundance of these plants in the basin during the late Holocene. Isotopic values in the studied paleosols revealed the presence of a mixed C 3/C 4 vegetation in the basin during the Last Glacial Stage, thus indicating the expansion of C 4 grasses. We hypothesized that lowered pCO 2 and possibly reduced rainfall resulted in the colonization of the tropical Andes by lowland C 4 grasses despite of prevailing cooler temperatures.

  17. Modeling naturally fractured carbonate as potential CGS reservoir: a case study from Sulcis Basin.

    Science.gov (United States)

    Chiara Tartarello, Maria; Bigi, Sabina; Ruggiero, Livio

    2017-04-01

    The naturally fractured carbonates have a great potential for Carbon Geological Storage purpose because they could offer the possibility for storage in that areas where no sandstone are available. In Italy, we studied the Sulcis Basin, an area situated in SW Sardinia, where the "Miliolitico Fm." represents the potential reservoir. This Formation consists of well bedded, about 50 m thick, mudstones and grainstones with Miliolidae, deposited in a lagoon environment during the Early Eocene. This formation has a very low primary porosity and permeability, so it is essential to characterize the fracture network that characterize the reservoir's capacity. We performed a detailed fracture analysis at the outcrop, using scan lines and scan areas techniques. We measured the fractures spacing, aperture, length and connectivity both linearly and on a surface. These parameters were used to build several Discrete Fracture Model, using Move 2016 (Midland Valley). In particular DFN were constructed varying length and aperture values to evaluate their influence on the total secondary porosity. The same approach was also utilized in the Nuraxi Figus coal mine, where the Miliolitico crops out at a depth of -480 m b.s.l., in more confined pressure condition. Here we collected detailed scan lines. Major fractures/faults that cross the whole tunnel were also measured. These data were integrated with the previous ones for the DFN generation. A separate fracture model were generated to represent the fault network, to evaluate the different component of the brittle deformation (small fault and fractures). The fracture modeling was performed using Move 2016 and Petrel (Schlumberger); than the results were compared. The results show that most of the secondary permeability and porosity is due to faults, through which fluid circulate. Some fractures sometimes are affected by karst phenomena, that influence their aperture.

  18. THE JURASSIC SEDIMENTARY EVOLUTION OF A CARBONATE PLATFORM INTO A DEEP-WATER BASIN, MT. MANGART (SLOVENIAN-ITALIAN BORDER

    Directory of Open Access Journals (Sweden)

    ANDREJ SMUC

    2005-03-01

    Full Text Available A complete Jurassic succession, recording the evolution from platform margin to a deep-water basin, is exposed at Mt. Mangart in the Julian Alps. The succession is a part of the Julian Nappe, where the Southern Alps overlap with the Dinarides. In the Jurassic, the area comprised part of the south Tethyan passive continental margin. The section was studied sedimentologically in detail and dated with radiolarians. It is divided into five lithostratigraphic units: Unit 1: Lower Jurassic shallow-water peloidal and oncoidal limestones; Unit 2: Pliensbachian distal shelf limestones rich in juvenile ammonites and sponge spicules topped by an Fe-Mn hardground; Unit 3: lower to possibly middle Toarcian sequence of black shales with interbedded siliceous limestone; Unit 4: upper Bajocian/Bathonian to lower Tithonian cherts, cherty limestones, and carbonate gravity-flow deposits; Unit 5: upper Tithonian red nodular cherty limestones with abundant calpionellids and aptychi. A stratigraphic gap, comprising the late Toarcian to early Bajocian, separates Unit 4 from Unit 3. In general, the succession correlates well with known Tethyan transgressive/regressive facies cycles. In addition, two periods of accelerated subsidence were recognized, the first, in the Pliensbachian, drowned the platform, the second, prior to the late Bajocian, created accommodation space for resedimented carbonate deposits from the adjacent Friuli Carbonate Platform. The present day position of the succession is between the Belluno Basin to the west and the Slovenian Basin to the south. The hitherto described successions of these two basins were located more distally from the Friuli Carbonate Platform than the Mt. Mangart succession. 

  19. Evolvement rules of basin flood risk under low-carbon mode. Part II: risk assessment of flood disaster under different land use patterns in the Haihe basin.

    Science.gov (United States)

    Li, Fawen; Wang, Liping; Zhao, Yong

    2017-08-01

    Land use pattern contains a large amount of information about the flood hazard-formative environments, which is the most sensitive factor in hazard-formative environments. In this paper, based on the land use pattern in 2008 (the base year) and in 2020 (the planning year), the comparative analysis of flood disaster risk changes in Haihe basin were studied by the spatial analysis function of ARCGIS and the analytic hierarchy process (AHP). The results showed the flood disaster risk in Haihe basin had an obvious zonality in the space, among which low risk was located in the northwest regions, and high risk was located in the southeast regions. Flood disaster risk in planning year was lower than in the base year. The risk value of 2020 in the mountain decreases from 0.445 to 0.430, while the risk value of the plain increases from 0.562 to 0.564. For the plain, high-risk area in 2020 is increased by 13.2%, which is the biggest change in risk grades. For the mountain, low-risk area and low risk area in 2020 are increased, and the low-risk area is the biggest increase, up to 37.7%. Meanwhile, high-risk area, high risk area, and medium risk area all tend to decrease, and the high-risk area is the biggest decrease, up to 32.6%. Overall, land use planning pattern under low-carbon mode is conducive to the Haihe basin flood control. The research can provide scientific foundations for basin land use planning and flood disaster risk management.

  20. An Assessment of Geological Carbon Storage Options in the Illinois Basin: Validation Phase

    Energy Technology Data Exchange (ETDEWEB)

    Finley, Robert

    2012-12-01

    The Midwest Geological Sequestration Consortium (MGSC) assessed the options for geological carbon dioxide (CO{sub 2}) storage in the 155,400 km{sup 2} (60,000 mi{sup 2}) Illinois Basin, which underlies most of Illinois, western Indiana, and western Kentucky. The region has annual CO{sub 2} emissions of about 265 million metric tonnes (292 million tons), primarily from 122 coal-fired electric generation facilities, some of which burn almost 4.5 million tonnes (5 million tons) of coal per year (U.S. Department of Energy, 2010). Validation Phase (Phase II) field tests gathered pilot data to update the Characterization Phase (Phase I) assessment of options for capture, transportation, and storage of CO{sub 2} emissions in three geological sink types: coal seams, oil fields, and saline reservoirs. Four small-scale field tests were conducted to determine the properties of rock units that control injectivity of CO{sub 2}, assess the total storage resources, examine the security of the overlying rock units that act as seals for the reservoirs, and develop ways to control and measure the safety of injection and storage processes. The MGSC designed field test operational plans for pilot sites based on the site screening process, MVA program needs, the selection of equipment related to CO{sub 2} injection, and design of a data acquisition system. Reservoir modeling, computational simulations, and statistical methods assessed and interpreted data gathered from the field tests. Monitoring, Verification, and Accounting (MVA) programs were established to detect leakage of injected CO{sub 2} and ensure public safety. Public outreach and education remained an important part of the project; meetings and presentations informed public and private regional stakeholders of the results and findings. A miscible (liquid) CO{sub 2} flood pilot project was conducted in the Clore Formation sandstone (Mississippian System, Chesterian Series) at Mumford Hills Field in Posey County, southwestern

  1. Cyclostratigraphy and chemostratigraphy of a bioclastic storm-dominated carbonate ramp (late Pliensbachian, Iberian Basin)

    Science.gov (United States)

    Val, Jorge; Bádenas, Beatriz; Aurell, Marcos; Rosales, Idoia

    2017-06-01

    Deposition of regressive successions and coeval positive trend in the oxygen stable isotope record in relatively deep marine successions of the upper Pliensbachian of western European basins have been related to a cooling interlude within the warm greenhouse conditions of the Pliensbachian. Sedimentological, cyclostratigraphic and chemostratigraphic analyses carried out in two upper Pliensbachian successions exposed in the Iberian Chain (Obón and San Pedro localities, Spain) allowed the characterization of the imprint of this cooling interlude on the relatively shallow areas of the Iberian carbonate ramp. The upper Pliensbachian succession is characterized by skeletal limestones and encompasses proximal mid-ramp to proximal outer-ramp facies, in which resedimentation and reworking by storm-induced flows controlled the accumulation of bioclastic debris. Two orders of high-frequency, metre-scale sequences have been identified: bundles of beds, and deepening-shallowing sets of bundles. According to the age calibration (previous biostratigraphic data and new strontium isotopes data) and correlation with nearby sections, these sequences are suggested as formed in tune with the short-term and long-term eccentricity Milankovitch cycles. The isotopic data from brachiopod shells and belemnite rostra indicate progressively increasing δ18O and slightly decreasing δ13C trends for the uppermost Pliensbachian Spinatum Zone, reflecting the influence of cooling conditions. However, facies analysis reflects that the expected coeval long-term regression was interrupted by a tectonically driven transgressive event in the uppermost part of the Spinatum Zone.

  2. A 30 year study of carbon, groundwater, and climate coupling in a large boreal peat basin

    Science.gov (United States)

    Glaser, P. H.; Siegel, D. I.; Chanton, J. P.; Reeve, A. S.; Slater, L.; Rosenberry, D. O.; Morin, P. J.; Carpenter, M.; Rhoades, J.; Nolan, J.; Parsekian, A.; O'Brien, M.; Sarkar, S.; Corbett, J. E.; D'Andrilli, J.

    2007-12-01

    Scaling biogeochemical processes across complex regional landscapes remains one of the most important challenges for deciphering the global methane cycle. For the past 30 years we have investigated the coupling of climate, groundwater, and methane cycling in the Glacial Lake Agassiz peatlands in northern Minnesota. Periodic droughts perturb the local and regional groundwater flow systems in this region altering the transport of inorganic solutes, organic acids and labile carbon substrates within the thick peat deposits. Two instrument stations at the bog crest and fen water track in the Red Lake peatland showed that large volumes of free-phase gas are trapped under confining layers in the deeper peat that episodically rupture to release large masses of methane bubbles to the atmosphere. These ebullition events are marked by abrupt depressuring cycles at depth and also by significant vertical and horizontal displacements of the peat surface. In the most recent phase of our investigations an integrated set of GPS stations and instrumented piezometers were installed to continuously pinpoint the location and calculate the magnitude of methane ebullition across a 160 square kilometer bog complex. The similarity of the vegetation patterns in this large bog complex to those found in other large peat basins in North America facilitates the transfer of these regional-scale ebullition fluxes to a broad swath of boreal America.

  3. [Correlation Among Soil Organic Carbon, Soil Inorganic Carbon and the Environmental Factors in a Typical Oasis in the Southern Edge of the Tarim Basin].

    Science.gov (United States)

    Gong, Lu; Zhu, Mei-ling; Liu, Zeng-yuan; Zhang, Xue-ni; Xie, Li-na

    2016-04-15

    We analyzed the differentiation among the environmental factors and soil organic/inorganic carbon contents of irrigated desert soil, brown desert soil, saline soil and aeolian sandy soil by classical statistics methods, and studied the correlation between soil carbon contents and the environmental factor by redundancy analysis (RDA) in a typical oasis of Yutian in the southern edge of the Tarim Basin. The results showed that the average contents of soil organic carbon and soil inorganic carbon were 2.51 g · kg⁻¹ and 25.63 g · kg⁻¹ respectively. The soil organic carbon content of the irrigated desert soil was significantly higher than those of brown desert soil, saline soil and aeolian sandy soil, while the inorganic carbon content of aeolian sandy soil was significantly higher than those of other soil types. The soil moisture and nutrient content were the highest in the irrigated desert soil and the lowest in the aeolian sandy sail. All soil types had high degree of salinization except the irrigated desert soil. The RDA results showed that the impacts of environmental factors on soil carbon contents ranked in order of importance were total nitrogen > available phosphorus > soil moisture > ground water depth > available potassium > pH > total salt. The soil carbon contents correlated extremely significantly with total nitrogen, available phosphorus, soil moisture and ground water depth (P 0.05).

  4. Carbon isotope discrimination in forest and pasture ecosystems of the Amazon Basin, Brazil

    Science.gov (United States)

    Ometto, Jean P. H. B.; Flanagan, Lawrence B.; Martinelli, Luiz A.; Moreira, Marcelo Z.; Higuchi, Niro; Ehleringer, James R.

    2002-12-01

    Our objective was to measure the stable carbon isotope composition of leaf tissue and CO2 released by respiration (δr), and to use this information as an estimate of changes in ecosystem isotopic discrimination that occur in response to seasonal and interannual changes in environmental conditions, and land-use change (forest-pasture conversion). We made measurements in primary forest and pastures in the Amazon Basin of Brazil. At the Santarém forest site, δr values showed a seasonal cycle varying from less than -29‰ to approximately -26‰. The observed seasonal change in δr was correlated with variation in the observed monthly precipitation. In contrast, there was no significant seasonal variation in δr at the Manaus forest site (average δr approximately -28‰), consistent with a narrower range of variation in monthly precipitation than occurred in Santarém. Despite substantial (9‰) vertical variation in leaf δ13C, the average δr values observed for all forest sites were similar to the δ13C values of the most exposed sun foliage of the dominant tree species. This suggested that the major portion of recently respired carbon dioxide in these forests was metabolized carbohydrate fixed by the sun leaves at the top of the forest canopy. There was no significant seasonal variation observed in the δ13C values of leaf organic matter for the forest sites. We sampled in pastures dominated by the C4 grass, Brachiaria spp., which is planted after forest vegetation has been cleared. The carbon isotope ratio of respired CO2 in pastures was enriched in 13C by approximately 10‰ compared to forest ecosystems. A significant temporal change occurred in δr after the Manaus pasture was burned. Burning removed much of the encroaching C3 shrub vegetation and so allowed an increased dominance of the C4 pasture grass, which resulted in higher δr values.

  5. Climate extremes dominating seasonal and interannual variations in carbon export from the Mississippi River Basin

    Science.gov (United States)

    Tian, Hanqin; Ren, Wei; Yang, Jia; Tao, Bo; Cai, Wei-Jun; Lohrenz, Steven E.; Hopkinson, Charles S.; Liu, Mingliang; Yang, Qichun; Lu, Chaoqun; Zhang, Bowen; Banger, Kamaljit; Pan, Shufen; He, Ruoying; Xue, Zuo

    2015-09-01

    Knowledge about the annual and seasonal patterns of organic and inorganic carbon (C) exports from the major rivers of the world to the coastal ocean is essential for our understanding and potential management of the global C budget so as to limit anthropogenic modification of global climate. Unfortunately our predictive understanding of what controls the timing, magnitude, and quality of C export is still rudimentary. Here we use a process-based coupled hydrologic/ecosystem biogeochemistry model (the Dynamic Land Ecosystem Model) to examine how climate variability and extreme events, changing land use, and atmospheric chemistry have affected the annual and seasonal patterns of C exports from the Mississippi River basin to the Gulf of Mexico. Our process-based simulations estimate that the average annual exports of dissolved organic C (DOC), particulate organic C (POC), and dissolved inorganic C (DIC) in the 2000s were 2.6 ± 0.4 Tg C yr-1, 3.4 ± 0.3 Tg C yr-1, and 18.8 ± 3.4 Tg C yr-1, respectively. Although land use change was the most important agent of change in C export over the past century, climate variability and extreme events (such as flooding and drought) were primarily responsible for seasonal and interannual variations in C export from the basin. The maximum seasonal export of DIC occurred in summer while for DOC and POC the maximum occurred in winter. Relative to the 10 year average (2001-2010), our modeling analysis indicates that the years of maximal and minimal C export cooccurred with wet and dry years (2008: 32% above average and 2006: 32% below average). Given Intergovernmental Panel on Climate Change-predicted changes in climate variability and the severity of rain events and droughts of wet and dry years for the remainder of the 21st century, our modeling results suggest major changes in the riverine link between the terrestrial and oceanic realms, which are likely to have a major impact on C delivery to the coastal ocean.

  6. Environmental and tectonic influences on the formation and distribution of carbonate nodules above the Springfield coal seam, southern Illinois Basin

    Energy Technology Data Exchange (ETDEWEB)

    Phillipson, S.E. [Mine Safety and Health Administration, Roof Control Division, Pittsburgh Safety and Health Technology Center, P.O. Box 18233, Pittsburgh, PA 15236 (United States)

    2005-11-10

    Carbonate nodules have been encountered for many years in the southern Illinois Basin, in parts of southern Illinois, southern Indiana, and southwestern Kentucky. The nodules occur as oblate spheroids of calcium carbonate that are isolated in the shale immediate roof of coal mines. They are common in the Springfield coal seam, known as the No. 5 seam in Illinois, and as the No. 9 seam in western Kentucky. Several different mechanisms have been proposed for the formation of various semi-spherical objects in coal measure rocks. The distribution and association with rooted horizons suggest that carbonate nodules in black fossiliferous shale observed in the roof of a studied mine in the Springfield seam represent pedogenic carbonate paleosols, which formed in a caliche-favoring environment subsequent to Springfield mire deposition. This interpretation is supported by {sup 87}Sr/{sup 86}Sr isotope ratios of 0.710893+/-13 to 0.711035+/-12, which indicate a freshwater rather than seawater source. Petrographic examination of rock textures and mineral grains indicates that nodules collected from two Illinois Basin coal mines are composed of subangular grains of fine-grained, crystalline microspar. Although the carbonate is not ferroan, iron hydroxide stains interstices between microspar grains. The rounded, commonly pinched boundaries of nodules truncate commonly imbricated microspar grains. In contrast, concentric growth patterns are not observed except as defined by secondary, subhedral to euhedral pyrite crystals that form a diffuse, concentric replacement zone around the nodule's outer rind. Polished slickensides, with well-developed radial slickenlines, are developed at highly compacted margins in black shale or mudstone that commonly encases the carbonate nodules. Of the 450 carbonate nodules documented at a study mine in the southern Illinois Basin, the long axes of 36% are preferentially aligned parallel to regional structures such as anticline axes and drag

  7. Advanced Characterization of Fractured Reservoirs in Carbonate Rocks: The Michigan Basin

    Energy Technology Data Exchange (ETDEWEB)

    Wood, James R.; Harrison, William B.

    2002-12-02

    The purpose of the study was to collect and analyze existing data on the Michigan Basin for fracture patterns on scales ranging form thin section to basin. The data acquisition phase has been successfully concluded with the compilation of several large digital databases containing nearly all the existing information on formation tops, lithology and hydrocarbon production over the entire Michigan Basin. These databases represent the cumulative result of over 80 years of drilling and exploration.

  8. The Oligocene carbonate platform of the Zagros Basin, SW Iran: An assessment of highly-complex geological heritage

    Science.gov (United States)

    Habibi, Tahereh; Ruban, Dmitry A.

    2017-05-01

    North Africa and the Middle East possess rich geological heritage, but the latter is yet to be fully identified and described. The Oligocene carbonate platform of the Zagros Basin in southwest Iran, which corresponds to the lower part of the Asmari Formation, has significant potential for geoconservation and geotourism. The types of the geological heritage, their value, and the possible geosites have been assessed. The studied deposits are interesting because of lithology (carbonate rocks), fossils (larger foraminifera, other microfossils, diverse marine invertebrates, fish microremains, and trace fossils), biostratigraphical developments, facies (homoclinal carbonate ramp) and signature of global events (glacioeustatic fluctuations), and outstanding hydrocarbon resources. The five main geological heritage types are sedimentary, palaeontological, stratigraphical, palaeogeographical, and economical, from which the palaeontological, palaeogeographical, and economical types are of global rank. The Khollar and Kavar sections in the Fars Province of Iran are recommended as geosites suitable for research, education, and tourism. The high complexity of the geological heritage linked to the Oligocene carbonate platform of the Zagros Basin implies the phenomenon of geodiversity should be understood with regard to the relationships between types and their values.

  9. Paleofacies of Eocene Lower Ngimbang Source Rocks in Cepu Area, East Java Basin based on Biomarkers and Carbon-13 Isotopes

    Science.gov (United States)

    Devi, Elok A.; Rachman, Faisal; Satyana, Awang H.; Fahrudin; Setyawan, Reddy

    2018-02-01

    The Eocene Lower Ngimbang carbonaceous shales are geochemically proven hydrocarbon source rocks in the East Java Basin. Sedimentary facies of source rock is important for the source evaluation that can be examined by using biomarkers and carbon-13 isotopes data. Furthermore, paleogeography of the source sedimentation can be reconstructed. The case study was conducted on rock samples of Lower Ngimbang from two exploration wells drilled in Cepu area, East Java Basin, Kujung-1 and Ngimbang-1 wells. The biomarker data include GC and GC-MS data of normal alkanes, isoprenoids, triterpanes, and steranes. Carbon-13 isotope data include saturate and aromatic fractions. Various crossplots of biomarker and carbon-13 isotope data of the Lower Ngimbang source samples from the two wells show that the source facies of Lower Ngimbang shales changed from transitional/deltaic setting at Kujung-1 well location to marginal marine setting at Ngimbang-1 well location. This reveals that the Eocene paleogeography of the Cepu area was composed of land area in the north and marine setting to the south. Biomarkers and carbon-13 isotopes are powerful data for reconstructing paleogeography and paleofacies. In the absence of fossils in some sedimentary facies, these geochemical data are good alternatives.

  10. Mechanisms for Olivine Carbonation at the Nili Fossae/Isidis Basin Boundary, Mars: Evidence of Intense Surface Aqueous Activity

    Science.gov (United States)

    Mustard, J. F.

    2015-12-01

    One of the most extensive surface deposits of carbonate on Mars is on the slopes of the Isidis Basin rising up to the Nili Fossae region (Ehlmann et al., 2008; Niles et al., 2012; Edwards and Ehlmann 2015). A key factor for the formation of carbonate in this region is the association of carbonate with olivine: this ubiquitous relationship shows the reactants and products are in direct association. There are four clear hypotheses for the geologic environment of formation. 1) Water-rock interaction in the shallow subsurface at slightly elevated temperatures altered olivine to Mg-carbonate perhaps through extended periods of heat and water with burial leading to olivine-serpentine-talc-chlorite alteration pathway (Brown et al., 2010; Viviano et al., 2013). 2) Olivine-rich material, heated by impact or volcanic processes, emplaced on top of a water-bearing phyllosilicate rich unit initiated hydrothermal alteration along the contact. 3) Olivine-rich rocks were weathered to carbonate at surface (cold) temperatures in a manner similar to olivine weathering of meteorites in Antarctica. 4) Carbonate precipitated from shallow ephemeral lakes. These hypotheses are quite different in their predictions of mineral assemblage, water requirements, and habitability. I will show new data and analyses that are providing insights to the question of the mineralogy and assemblages of carbonate-bearing units in the region, diagostic of processes. It is becoming more evident that surface aqueous activity, perhaps involving an extensive cryosphere in the form of Hesperian ice sheets.

  11. Stable C, O and clumped isotope systematics and 14C geochronology of carbonates from the Quaternary Chewaucan closed-basin lake system, Great Basin, USA: Implications for paleoenvironmental reconstructions using carbonates

    Science.gov (United States)

    Hudson, Adam M.; Quade, Jay; Ali, Guleed; Boyle, Douglas; Bassett, Scott; Huntington, Katharine W.; De los Santos, Marie G.; Cohen, Andrew S.; Lin, Ke; Wang, Xiangfeng

    2017-09-01

    Isotopic compositions of lacustrine carbonates are commonly used for dating and paleoenvironmental reconstructions. Here we use carbonate δ13C and δ18O, clumped (Δ47), and 14C compositions to better understand the carbonate isotope system in closed-basin lakes and trace the paleohydrologic and temperature evolution in the Chewaucan closed-basin lake system, northern Great Basin, USA, over the Last Glacial/Holocene transition. We focus on shorezone tufas to establish that they form in isotopic equilibrium with lake water and DIC, they can be dated reliably using 14C, and their clumped isotope composition can be used to reconstruct past lake temperature. Calculations of the DIC budget and reservoir age for the lake indicate residence time is short, and dominated by exchange with atmospheric CO2 at all past lake levels. Modern lake DIC and shorezone tufas yield δ13C and 14C values consistent with isotopic equilibrium with recent fossil fuel and bomb-influenced atmospheric CO2, supporting these calculations. δ13C values of fossil tufas are also consistent with isotopic equilibrium with pre-industrial atmospheric CO2 at all shoreline elevations. This indicates that the 14C reservoir effect for this material is negligible. Clumped isotope (Δ47) results indicate shorezone tufas record mean annual lake temperature. Modern (average 13 ± 2 °C) and 18 ka BP-age tufas (average 6 ± 2 °C) have significantly different temperatures consistent with mean annual temperature lowering of 7 ± 3 °C (1 SE) under full glacial conditions. For shorezone tufas and other lake carbonates, including spring mounds, mollusk shells, and ostracod tests, overall δ13C and δ18O values co-vary according to the relative contribution of spring and lacustrine end member DIC and water compositions in the drainage system, but specific isotope values depend strongly upon sample context and are not well correlated with past lake depth. This contrasts with the interpretation that carbonate

  12. Stable C, O and clumped isotope systematics and 14C geochronology of carbonates from the Quaternary Chewaucan closed-basin lake system, Great Basin, USA: Implications for paleoenvironmental reconstructions using carbonates

    Science.gov (United States)

    Hudson, Adam; Quade, Jay; Ali, Guleed; Boyle, Douglas P.; Bassett, Scott; Huntington, Katharine W.; De los Santos, Marie G.; Cohen, Andrew S.; Lin, Ke; Wang, Xiangfeng

    2017-01-01

    Isotopic compositions of lacustrine carbonates are commonly used for dating and paleoenvironmental reconstructions. Here we use carbonate δ13C and δ18O, clumped (Δ47), and 14C compositions to better understand the carbonate isotope system in closed-basin lakes and trace the paleohydrologic and temperature evolution in the Chewaucan closed-basin lake system, northern Great Basin, USA, over the Last Glacial/Holocene transition. We focus on shorezone tufas to establish that they form in isotopic equilibrium with lake water and DIC, they can be dated reliably using 14C, and their clumped isotope composition can be used to reconstruct past lake temperature. Calculations of the DIC budget and reservoir age for the lake indicate residence time is short, and dominated by exchange with atmospheric CO2 at all past lake levels. Modern lake DIC and shorezone tufas yield δ13C and 14C values consistent with isotopic equilibrium with recent fossil fuel and bomb-influenced atmospheric CO2, supporting these calculations. δ13C values of fossil tufas are also consistent with isotopic equilibrium with pre-industrial atmospheric CO2 at all shoreline elevations. This indicates that the 14C reservoir effect for this material is negligible. Clumped isotope (Δ47) results indicate shorezone tufas record mean annual lake temperature. Modern (average 13 ± 2 °C) and 18 ka BP-age tufas (average 6 ± 2 °C) have significantly different temperatures consistent with mean annual temperature lowering of 7 ± 3 °C (1 SE) under full glacial conditions. For shorezone tufas and other lake carbonates, including spring mounds, mollusk shells, and ostracod tests, overall δ13C and δ18O values co-vary according to the relative contribution of spring and lacustrine end member DIC and water compositions in the drainage system, but specific isotope values depend strongly upon sample context and are not well correlated with past lake depth. This contrasts with the interpretation that carbonate

  13. Variability in lateral carbon export from four major tributaries in the Upper Mississippi River Basin

    Science.gov (United States)

    Stackpoole, S. M.; Dornblaser, M.; Stets, E.; Wilson, S.; Striegl, R. G.

    2016-12-01

    Rivers process carbon (C) inputs from terrestrial ecosystems and produce new organic matter during downstream transport to the coastal ocean. Our study focuses on lateral C fluxes from the four major rivers that join together to comprise the upper Mississippi River in Wisconsin and Minnesota, USA. River water chemistry data and daily discharge values for water years 2015 and 2016 were assimilated into the LOADEST model to estimate dissolved inorganic C (DIC) and dissolved organic C (DOC) fluxes from the Minnesota, Mississippi (headwaters), Saint Croix, and Chippewa Rivers. These watersheds contain wetlands, forests, agriculture, and urban land cover, including the Minneapolis and St. Paul, MN metropolitan area. Discharge from the four major tributaries is dominated by snowmelt, with about 40 percent of the annual flow occurring from March through May. Annual DIC yields for the four watersheds were between 4.8 and 7.2 g C m2 yr-1, and DOC yields ranged between 0.7 and 4.4 g C m2 yr-1. River C chemistry differed strongly with DIC dominating fluxes in the Minnesota River while DIC and DOC fluxes were nearly equivalent in the Chippewa. The sum of the four tributaries annual flow represents about 90% of the total flow at a downstream site on the main stem of the Mississippi River near Wabasha, Minnesota. The DOC yield for this site was 2 g C m2 yr-1, represents an integrated river C signal for roughly 147,000 km2 of upstream drainage area. This C flux reflects mixing of the four upstream tributary sites, in-stream DOC losses by mineralization, adsorption, and photolysis, and in-steam production. An analysis of hydrology, geology, and land-use will be applied to this nested sampling design to help identify temporal and spatial patterns of key sources of aquatic C in the upper Mississippi River Basin and their potential response to future change.

  14. Vegetation Carbon Storage, Spatial Patterns and Response to Altitude in Lancang River Basin, Southwest China

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-01-01

    Full Text Available Vegetation plays a very important role of carbon (C sinks in the global C cycle. With its complex terrain and diverse vegetation types, the Lancang River Basin (LRB of southwest China has huge C storage capacity. Therefore, understanding the spatial variations and controlling mechanisms of vegetation C storage is important to understand the regional C cycle. In this study, data from a forest inventory and field plots were used to estimate and map vegetation C storage distribution in the LRB, to qualify the quantitative relationships between vegetation C density and altitude at sublot and township scale, and a linear model or polynomial model was used to identify the relationship between C density and altitude at two spatial scales and two statistical scales. The results showed that a total of 300.32 Tg C was stored in the LRB, an important C sink in China. The majority of C storage was contributed by forests, notably oaks. The vegetation C storage exhibited nonlinear variation with latitudinal gradients. Altitude had tremendous influences on spatial patterns of vegetation C storage of three geomorphological types in the LRB. C storage decreased with increasing altitude at both town and sublot scales in the flat river valley (FRV region and the mid-low mountains gorge (MMG region, and first increased then decreased in the alpine gorge (AG region. This revealed that, in southwest China, altitude changes the latitudinal patterns of vegetation C storage; especially in the AG area, C density in the mid-altitude (3100 m area was higher than that of adjacent areas.

  15. Influence of Plio-Pleistocene basin hydrology on the Turkana hominin enamel carbonate δ(18)O values.

    Science.gov (United States)

    Quinn, Rhonda L

    2015-09-01

    Stable oxygen isotopes of hominin enamel carbonate (δ(18)OEC) provide a window into aspects of past drinking behavior and diet, body size, breastfeeding and weaning, mobility, and paleoclimate. It is tempting to compare all hominins across time and space in order to gauge species-level adaptations to changing environments and niche separation between those living sympatrically. Basinal, sub-basinal, and micro-environmental differences, however, may exert an influence on variation in enamel carbonate isotopic values that must be reconciled before hominin species across Africa can be meaningfully compared. Plio-Pleistocene Turkana hominin δ(18)OEC values show a considerable spread, potentially revealing many intrinsic and extrinsic contributing factors operating on different scales. In this study, I examine Turkana hominin δ(18)OEC values relative to identity (taxon, tooth type and number, body size of taxon), dietary (δ(13)C value, Turkana coeval and modern mammalian δ(18)OEC values), and contextual (time, depositional environment) information of each specimen and collection locality and discuss various potential influences. Turkana hominin δ(18)OEC values may primarily reflect differences in imbibed water sources (lake vs. river) as a function of evolving basin hydrology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Sensitivity of Arctic Permafrost Carbon in the Mackenzie River Basin: A substrate addition and incubation experiment

    Science.gov (United States)

    Hedgpeth, A.; Beilman, D.; Crow, S. E.

    2014-12-01

    Arctic soil organic matter (SOM) mineralization processes are fundamental to the functioning of high latitude soils in relation to nutrients, stability, and feedbacks to atmospheric CO2 and climate. The arctic permafrost zone covers 25% of the northern hemisphere and contains 1672Pg of soil carbon (C). 88% of this C currently resides in frozen soils that are vulnerable to environmental change. For instance, arctic growing seasons may be lengthened, resulting in an increase in plant productivity and rate of below ground labile C inputs as root exudates. Understanding controls on Arctic SOM dynamics requires recognition that labile C inputs have the potential to significantly affect mineralization of previously stable SOM, also known as 'priming effects'. We conducted a substrate addition incubation experiment to quantify and compare respiration in highly organic (42-48 %C) permafrost soils along a north-south transect in western Canada. Near surface soils (10-20 cm) were collected from permafrost peatland sites in the Mackenzie River Basin from 69.2-62.6°N. The surface soils are fairly young (Δ14C values > -140.0) and can be assumed to contain relatively reactive soil carbon. To assess whether addition of labile substrate alters SOM decomposition dynamics, 4.77-11.75 g of permafrost soil were spiked with 0.5 mg D-glucose g-1 soil and incubated at 5°C. A mass balance approach was used to determin substrate-induced respiration and preliminary results suggest a potential for positive priming in these C-rich soils. Baseline respiration rates from the three sites were similar (0.067-0.263 mg CO2 g-1 soil C) yet show some site-specific trends. The rate at which added substrate was utilized within these soils suggests that other factors besides temperature and soil C content are controlling substrate consumption and its effect on SOM decomposition. Microbial activity can be stimulated by substrate addition to such an extent that SOM turnover is enhanced, suggesting that

  17. Characterization of the Triassic Newark Basin of New York and New Jersey for geologic storage of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Daniel J. [Geostock Sandia, LLC, Houston, TX (United States)

    2017-06-30

    The Newark Basin is a Triassic-aged rift basin underlying densely populated, industrialized sections of New York, New Jersey and Pennsylvania. The Basin is an elongate half-graben encompassing an area of more than 7,510 square-kilometers (2,900 square-miles), and could represent a key storage component for commercial scale management of carbon dioxide emissions via geologic sequestration. The project team first acquired published reports, surface and subsurface maps, and seismic data, which formed the basis for a three-dimensional model framework for the northern end of the Basin incorporating stratigraphic, hydrologic, and water quality data. Field investigations included drilling, coring, and logging of two stratigraphic test borings in Clarkstown, NY (Exit 14 Tandem Lot Well No. 1), drilled to a depth of 2,099 meters (6,885 feet); and Palisades, NY (Lamont-Doherty Earth Observatory Test Well No. 4) drilled to a depth of 549 meters (1,802 feet). Two two-dimensional seismic reflection data lines arrayed perpendicularly were acquired by Schlumberger/WesternGeco to help characterize the structure and stratigraphy and as part of pre-drilling field screening activities for the deep stratigraphic borehole. A total of 47 meters (155 feet) of continuous whole core was recovered from the Tandem Lot boring from depths of 1,393 meters (4,570 feet) to 1,486 meters (4,877 feet). Twenty-five horizontal rotary cores were collected in mudstones and sandstones in the surface casing hole and fifty-two cores were taken in various lithologies in the deep borehole. Rotary core plugs were analyzed by Weatherford Laboratories for routine and advanced testing. Rotary core plug trim end thin sections were evaluated by the New York State Museum for mineralogical analysis and porosity estimation. Using core samples, Lawrence Berkley National Laboratory designed and completed laboratory experiments and numerical modeling analyses to characterize the dissolution and reaction of carbon

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

    Science.gov (United States)

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

    2017-08-01

    A 200-m thick carbonate succession has been deposited in shallow-water, saline lake environments during the Priabonian-Rupelian in the Issirac Basin (South-East France). The palaeoenvironmental and palaeogeographic significance of such saline lake carbonates has been characterized on the basis of a multi-proxy analysis including 1) depositional and diagenetic features, 2) biological components (molluscs, ostracods, benthic foraminifers, characean) and 3) carbon, oxygen and strontium stable isotopes. Biological associations are indicative of dominantly shallow (cycles of lake transgression, corresponding to the three main sedimentary units (U1, U2 and U3). Relative lake-level, degree of connectivity with surrounding lakes and climate (dry versus humid) are the three key factors controlling the water composition, carbonate production and depositional environments in the Issirac lake. Although the ASCI (Alès-Issirac-Saint-Chaptes) lacustrine system likely represents an athalassic (inland) lake system evolving through times, the stable isotope composition (C, O and Sr) of carbonates strongly suggests the occurrence of transient connections of the ASCI lake water with water bodies influenced by seawater and/or fed with sulfates deriving from Triassic evaporites. The Issirac Basin may be therefore interpreted as a sill area connecting the ASCI lacustrine system with the Rhône valley (Mormoiron and Valence) saline lake systems during maximum flooding periods. Finally, changes in depositional features, biota and stable isotope composition of carbonates in unit U3 suggest a transition from relatively dry to more humid climate during the uppermost Priabonian or earliest Rupelian.

  19. The Miocene Sommières basin, SE France: Bioclastic carbonates in a tide-dominated depositional system

    Science.gov (United States)

    Reynaud, Jean-Yves; James, Noël P.

    2012-12-01

    The Miocene Sommières Basin in SE France is a semi-enclosed depression that was connected to the Mediterranean Sea by a flooded paleo-incised valley and then filled by a suite of sediments comprising carbonate grains coming from temperate factories that were largely deposited in tidal-dominated paleoenvironments. The strata are partitioned into two sequences that reflect repeated flooding of the incised valley system, one of several similar situations in this region of France. The carbonate grains are mostly bioclasts, namely from barnacles, bryozoans, coralline algae (encrusting, branching, and rhodoliths), echinoids, and benthic foraminifers (large and small) with ostracods, sponge spicules and planktic foraminifers prominent in muddy facies. Particles were produced by shallow water carbonate factories on hard substrates (valley walls in particular), associated with subaqueous dunes, and in deeper water basinal settings. Each depositional sequence is underlain by an eroded and bored hard surface that is progressively overlain by TST subaqueous tidal dunes or storm deposits that grade up, in one case, into HST marls (the HST of the upper sequence has been removed by erosion). The lower sequence is ebb tide dominated whereas the upper sequence is flood tide dominated. The succession is interpreted to represent a TST whose tidal currents were focused by the narrow valley and a HST that reflected flooding of the overbanks. This stratigraphic and depositional motif is comparable to that in other spatially separated Neogene paleovalleys that are filled with tide-dominated clastic carbonates in the region. Together with other recently documented similar systems, these limestones constitute an important new group of carbonate sand bodies in the carbonate depositional realm.

  20. The importance of some carbonate aquifers in the Guadalquivir river basin; Importancia de algunos acuiferos carbonatados representativos de la cuenca del Guadalquivir

    Energy Technology Data Exchange (ETDEWEB)

    Pulido Boch, A.; Lopez Chicano, M.

    1995-07-01

    Carbonate aquifers play an important role in the Guadalquivir river basin, although, until present days, there are very few wells exploiting them. We can distinguish two kinds of carbonate aquifers: fissurated and karstic. In the first group, we consider the Alpujarride carbonates from the western Sierra Nevada- Alfaguara border; in the second, the most important are: Cazorla and Segura Sierras-source of the Guadalquivir river- and Sierra Gorda. The main hydrogeological characteristics of these aquifers are described and we make some reflexions about the role that the aquifers can play in the total resources of the basin. (Author)

  1. Sulfur, carbon, and oxygen isotope variations in submarine hydrothermal deposits of Guaymas Basin, Gulf of California, USA

    Science.gov (United States)

    Peter, J.M.; Shanks, Wayne C.

    1992-01-01

    Sulfur, carbon, and oxygen isotope values were measured in sulfide, sulfate, and carbonate from hydrothermal chimney, spire, and mound samples in the southern trough of Guaymas Basin, Gulf of California, USA. ??34S values of sulfides range from -3.7 to 4.5%. and indicate that sulfur originated from several sources: 1. (1) dissolution of 0??? sulfide contained within basaltic rocks, 2. (2) thermal reduction of seawater sulfate during sediment alteration reactions in feeder zones to give sulfide with positive ??34S, and 3. (3) entrainment or leaching of isotopically light (negative-??34S) bacteriogenic sulfide from sediments underlying the deposits. ??34S of barite and anhydrite indicate sulfur derivation mainly from unfractionated seawater sulfate, although some samples show evidence of sulfate reduction and sulfide oxidation reactions during mixing within chimneys. Oxygen isotope temperatures calculated for chimney calcites are in reasonable agreement with measured vent fluid temperatures and fluid inclusion trapping temperatures. Hydrothermal fluids that formed calcite-rich chimneys in the southern trough of Guaymas Basin were enriched in 18O with respect to seawater by about 2.4??? due to isotopic exchange with sedimentary and/or basaltic rocks. Carbon isotope values of calcite range from -9.6 to -14.0??? ??34CpDB, indicating that carbon was derived in approximately equal quantities from the dissolution of marine carbonate minerals and the oxidation of organic matter during migration of hydrothermal fluid through the underlying sediment column. Statistically significant positive, linear correlations of ??34S, ??34C, and ??18O of sulfides and calcites with geographic location within the southern trough of Guaymas Basin are best explained by variations in water/rock ( w r) ratios or sediment reactivity within subsurface alteration zones. Low w r ratios and the leaching of detrital carbonates and bacteriogenic sulfides at the southern vent sites result in relatively

  2. Organic carbon accumulation in modern sediments of the Angola basin influenced by the Congo deep-sea fan

    Science.gov (United States)

    Baudin, François; Martinez, Philippe; Dennielou, Bernard; Charlier, Karine; Marsset, Tania; Droz, Laurence; Rabouille, Christophe

    2017-08-01

    Geochemical data (total organic carbon-TOC content, δ13Corg, C:N, Rock-Eval analyses) were obtained on 150 core tops from the Angola basin, with a special focus on the Congo deep-sea fan. Combined with the previously published data, the resulting dataset (322 stations) shows a good spatial and bathymetric representativeness. TOC content and δ13Corg maps of the Angola basin were generated using this enhanced dataset. The main difference in our map with previously published ones is the high terrestrial organic matter content observed downslope along the active turbidite channel of the Congo deep-sea fan till the distal lobe complex near 5000 m of water-depth. Interpretation of downslope trends in TOC content and organic matter composition indicates that lateral particle transport by turbidity currents is the primary mechanism controlling supply and burial of organic matter in the bathypelagic depths.

  3. LBA-ECO CD-06 Isotopic Composition of Carbon Fractions, Amazon Basin River Water

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes measurements of standard geochemical variables, dissolved CO2, dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), fine...

  4. LBA-ECO CD-06 Isotopic Composition of Carbon Fractions, Amazon Basin River Water

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set includes measurements of standard geochemical variables, dissolved CO2, dissolved inorganic carbon (DIC), dissolved organic carbon (DOC),...

  5. Sources and Dynamics of Inorganic Carbon within the Upper Reaches of the Xi River Basin, Southwest China.

    Directory of Open Access Journals (Sweden)

    Junyu Zou

    Full Text Available The carbon isotopic composition (δ13C of dissolved and particulate inorganic carbon (DIC; PIC was used to compare and analyze the origin, dynamics and evolution of inorganic carbon in two headwater tributaries of the Xi River, Southwest China. Carbonate dissolution and soil CO2 were regarded as the primary sources of DIC on the basis of δ13CDIC values which varied along the Nanpan and Beipan Rivers, from -13.9‰ to 8.1‰. Spatial trends in DIC differed between the two rivers (i.e., the tributaries, in part because factors controlling pCO2, which strongly affected carbonate dissolution, differed between the two river basins. Transport of soil CO2 and organic carbon through hydrologic conduits predominately controlled the levels of pCO2 in the Nanpan River. However, pCO2 along the upper reaches of the Nanpan River also was controlled by the extent of urbanization and industrialization relative to agriculture. DIC concentrations in the highly urbanized upper reaches of the Nanpan River were typical higher than in other carbonate-dominated areas of the upper Xi River. Within the Beipan River, the oxidation of organic carbon is the primary process that maintains pCO2 levels. The pCO2 within the Beipan River was more affected by sulfuric acid from coal industries, inputs from a scenic spot, and groundwater than along the Nanpan River. With regards to PIC, the contents and δ13C values in the Nanpan River were generally lower than those in the Beipan River, indicating that chemical and physical weathering contributes more marine carbonate detritus to the PIC along the Beipan River. The CO2 evasion flux from the Nanpan River was higher than that in the Beipan River, and generally higher than along the middle and lower reaches of the Xi River, demonstrating that the Nanpan River is an important net source of atmospheric CO2 in Southwest China.

  6. Dynamics of dissolved organic carbon (DOC) through stormwater basins designed for groundwater recharge in urban area: Assessment of retention efficiency.

    Science.gov (United States)

    Mermillod-Blondin, Florian; Simon, Laurent; Maazouzi, Chafik; Foulquier, Arnaud; Delolme, Cécile; Marmonier, Pierre

    2015-09-15

    Managed aquifer recharge (MAR) has been developed in many countries to limit the risk of urban flooding and compensate for reduced groundwater recharge in urban areas. The environmental performances of MAR systems like infiltration basins depend on the efficiency of soil and vadose zone to retain stormwater-derived contaminants. However, these performances need to be finely evaluated for stormwater-derived dissolved organic matter (DOM) that can affect groundwater quality. Therefore, this study examined the performance of MAR systems to process DOM during its transfer from infiltration basins to an urban aquifer. DOM characteristics (fluorescent spectroscopic properties, biodegradable and refractory fractions of dissolved organic carbon -DOC-, consumption by micro-organisms during incubation in slow filtration sediment columns) were measured in stormwater during its transfer through three infiltration basins during a stormwater event. DOC concentrations sharply decreased from surface to the aquifer for the three MAR sites. This pattern was largely due to the retention of biodegradable DOC which was more than 75% for the three MAR sites, whereas the retention of refractory DOC was more variable and globally less important (from 18% to 61% depending on MAR site). Slow filtration column experiments also showed that DOC retention during stormwater infiltration through soil and vadose zone was mainly due to aerobic microbial consumption of the biodegradable fraction of DOC. In parallel, measurements of DOM characteristics from groundwaters influenced or not by MAR demonstrated that stormwater infiltration increased DOC quantity without affecting its quality (% of biodegradable DOC and relative aromatic carbon content -estimated by SUVA254-). The present study demonstrated that processes occurring in soil and vadose zone of MAR sites were enough efficient to limit DOC fluxes to the aquifer. Nevertheless, the enrichments of DOC concentrations measured in groundwater below

  7. The high-resolution stratigraphic architecture and evolution of the Burdigalian carbonate-silici-clastic sedimentary systems on the Mut Basin, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Bassant, Ph.

    1999-06-01

    The subject of this doctorate study are the Lower Miocene (Burdigalian) carbonate systems in the Mut basin, in south central Turkey. This area is chosen because it presents extraordinary large (seismic) scale 3D outcrops showing depositional geometries. In addition, these carbonates are considered as good outcrop analogues for time equivalent carbonate buildups in the Far East, that are oil and gas bearing. The carbonates were deposited in a complex relict topography, following a tectonically active phase in the Oligocene. During the Burdigalian transgression shallow platform carbonates were deposited in a variety of settings, locally accompanied by some silici-clastic input. Observations on the strata geometries and the facies were combined into a high resolution sequence stratigraphic framework controlled by bio-stratigraphy. With the help of relative sea level curves constructed for the three studied sites, a basin-wide correlation scheme is proposed. This chronostratigraphic framework permits the recognition of condensation and omission surfaces in the basinal and platform settings, to identify basin-wide variations in sedimentation pattern, and to evaluate the relative influence of tectonism, eustatism and the environment. The exceptional quality of the outcrops with its variety of environments, and its location at the Tethys margin, make this a good candidate for a reference model for Burdigalian reef and platform architectures. Examples of a quantitative approach of the geometries of potential carbonate reservoir bodies are given in the annex. The data-files are incorporated in the carbonate reservoir body database CARABAS. (author)

  8. Carbon isotopic record of terrestrial ecosystems spanning the Late Miocene extinction of Oreopithecus bambolii, Baccinello Basin (Tuscany, Italy).

    Science.gov (United States)

    Matson, Samuel D; Rook, Lorenzo; Oms, Oriol; Fox, David L

    2012-07-01

    Oreopithecus bambolii is a Late Miocene hominoid with an extensive fossil record in the Baccinello Basin (Tuscany, Italy), and was the only western European hominoid to survive a major extinction event ca. 9.6 Ma (millions of years ago). Oreopithecus lived in the insular Tusco-Sardinian paleobioprovince, where it evolved many unique anatomical specializations that make it important for understanding the mechanisms and history of Late Miocene hominoid evolution. The eventual extinction of Oreopithecus and its associated fauna ca. 6.5 Ma has generally been attributed to interaction with species that arrived from continental Europe following tectonic collision of the Tusco-Sardinian province with mainland Italy, but palynological, paleontological, and sedimentological records indicate an environmental shift toward more variable climate across the extinction event. To explore the possibility of environmental change as a contributing factor in the extinction of Oreopithecus, we developed a stable carbon and oxygen isotope record from organic matter in paleosols from the Baccinello Basin. These data show very low temporal and spatial variability (indicating plant ecosystem stability through time and space) and provide no evidence for ecologically significant changes in floral composition spanning the extinction event, suggesting that environmental change was not an underlying cause for the extinction of Oreopithecus and its associated fauna. The carbon isotope values fall entirely within the range of isotopic variability for modern plants following the C(3) photosynthetic pathway (trees, shrubs, cool-season grasses), indicating that C(4) vegetation (warm-season grasses) was not an important component of biomass. When corrected for temporal variation in the carbon isotopic composition of atmospheric carbon dioxide, the paleosol carbon isotope values are consistent with predicted values based on modern plants and the Baccinello palynoflora, supporting the reliability of

  9. Warming in the Yukon River Basin is Likely to Release Substantial Amounts of Soil Organic Carbon

    Science.gov (United States)

    Juday, G. P.; Huntington, T. G.

    2005-12-01

    In recent decades the Yukon River Basin (YRB) in northwestern Canada and central Alaska has experienced a substantial warming trend resulting in a variety of geophysical and biological responses. Climatologic measurements consistent with rapid warming in the YRB during the last several decades of the 20th century include surface air temperature (especially daily minima), number of frost-free days, and the number of very warm days. During the 20th century daily maxima in the warm season in the YRB have increased only weakly, and modest autumn cooling occurred. Indirect indicators of warming include shrinkage in lake area, decreases in glacier mass, increased fire frequency and annual area burned, and changes in permafrost thickness and permafrost temperature. Changes in tree growth rates and susceptibility to pests have been related to warming and drying in interior Alaska. Oral histories of Alaska Natives have also revealed many other warming related changes in the YRB. If ongoing warming trends continue there is a concern that large stores of soil organic carbon (SOC) will be at risk for release to the atmosphere through heterotrophic decomposition. Warming tends to accelerate microbial decomposition at a faster rate than net primary productivity. One of the most important effects of warming in the YRB is likely to be its influence on the hydrologic and cryospheric regimes. Warming may be accompanied by soil drying and lowering of the water table in wetlands and lakes exposing more SOC to aerobic decomposition. A substantial portion of the YRB is underlain by permafrost that thaws to a variable depth (active layer) each summer. Increasing the thickness of the active layer exposes more SOC to microbial decomposition. Increasing the burned area results in direct SOC losses by oxidation during the fire and decreases albedo that warms surface soils and increases the thickness of the active layer. Warming and increasing length of the growing season increases seasonal

  10. Types and characteristics of carbonate reservoirs and their implication on hydrocarbon exploration: A case study from the eastern Tarim Basin, NW China

    OpenAIRE

    Huang, Shiwei; Zhang, You; Zheng, Xingping; Zhu, Qifa; Shao, Guanming; Cao, Yanqing; Chen, Xiguang; Yang, Zhao; Bai, Xiaojia

    2017-01-01

    Carbonate rocks are deposited in the Ordovician, Cambrian, and Sinian of eastern Tarim Basin with a cumulative maximum thickness exceeding 2000 m. They are the main carriers of oil and gas, and a great deal of natural gas has been found there in the past five years. Based on lithofacies and reservoir differences, natural gas exploration domains of eastern Tarim Basin can be classified into five types: Ordovician platform limestone; Ordovician platform dolomite; Cambrian platform margin mound ...

  11. Comprehensive insight of the Cambrian carbonate platform types as well as margin segmentation characteristics' exploration in Tarim Basin, China

    Directory of Open Access Journals (Sweden)

    Xinfeng Ni

    2016-02-01

    Full Text Available The carbonate platform types and features of the platform margin belt plays an important role in controlling the reservoir formation; it also affects the relationship between reservoirs and caps. The Cambrian carbonate platform in the Tarim Basin underwent three evolutionary processes, namely, the Early Cambrian ramp platform, the Middle Cambrian edging evaporative platform, and the Late Cambrian edging platform; the northern platform margin was the deposition type, whereas the eastern platform margin was for fault control, additionally, the Lungu-Gucheng had evident sectional differences. The line from Wushi-Kashi-Maigaiti-Hetian to Minfeng of the southwestern Tarim Basin was an ancient land in the Early Cambrian. Through evolution, the sea level raised the underwater lows in the Middle and Late Cambrian period that possibly developed it to platform edge deposits in the Late Cambrian. The carbonate platform margin of both steep slope and gentle slope formed different reservoir-seal assemblages. The Upper Cambrian aggradation-progradation platform margin reservoir in the steep slope of the eastern Lungu and Gucheng area was developed with good connectivity, its caprock had been always the key of the platform margin reservoir-seal assemblages. Therefore, the reef-beach located behind the platform margin belt near the seaside of the lagoon had favorable reservoirs; the reservoirs often overlaid carbonate caprock which formed good reservoir-seal assemblages. The platform margin belt in the gentle slope in the Well Yingmai 7-Well Yingmai 8, in west Tabei, was a dolomite reservoir for algal mound and reef-bank complex with caprock of middle-lower Cambrian dolomicrite, gypsum dolomite, and mud dolomite. Aforementioned dense layers' reservoir-seal assemblage was superior to that of the eastern Lungu and Gucheng that had better exploration prospects.

  12. Main factors for large accumulations of natural gas in the marine carbonate strata of the Eastern Sichuan Basin, China

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    Quanyou Liu

    2017-04-01

    Full Text Available The natural gas accumulation zone, where the marine carbonate rock strata are developed, was formed in the eastern Sichuan Basin under the influence of several main tectonic movements (Caledonian Movement, Indosinian Movement, Yanshanian Movement, and Himalayan Movement. Most natural gas reservoirs exhibit the structural-stratigraphic traps together with multistage accumulation, late-stage adjustment and reformation, et cetera. The natural gas accumulation zone (or so-called gas reservoir groups is controlled by the following main factors: multi-sourced and multi-formed hydrocarbons for marine source rocks (i.e. Lower Silurian Longmaxi Formation, Lower Permian, Upper Permian Longtan Formation, paleo-uplift, paleoslope, and the hinge belt controlled by the steep dip structures, namely the Lower and Middle Triassic high-quality gypsum. Three sets of high-quality source rocks (i.e. S1l, P1, P2l account for the abundant hydrocarbon supply for natural gas accumulation in the eastern Sichuan area, especially in the destructed oil reservoir formed earlier. The said destructed oil reservoir not only provides the preservation space for natural gas reservoir that will take place later, but it also provides the hydrocarbon source for thermal cracking of hydrocarbons and thermochemical sulfate reduction (TSR. Although the gas reservoirs in the eastern part of the Sichuan Basin experienced multi-stage adjustment and reformation at later times, the thick and high-quality gypsum as well as the mudstone, as available caprocks, have offered a good preservation condition for the underlying gas reservoirs. The paleohighs (e.g. Luzhou paleohigh and Kaijiang paleohigh, the Permian platform margin slope, and the structurally transformed slope under the function of the steep dip anticline in the eastern Sichuan not only form the high-quality carbonate reservoir, but they also became favorable for oil and gas accumulation. The difference in hydrocarbon generation

  13. Post-glacial climate forcing of surface processes in the Ganges-Brahmaputra river basin and implications for carbon sequestration

    Science.gov (United States)

    Hein, Christopher J.; Galy, Valier; Galy, Albert; France-Lanord, Christian; Kudrass, Hermann; Schwenk, Tilmann

    2017-11-01

    Climate has been proposed to control both the rate of terrestrial silicate weathering and the export rate of associated sediments and terrestrial organic carbon to river-dominated margins - and thus the rate of sequestration of atmospheric CO2 in the coastal ocean - over glacial-interglacial timescales. Focused on the Ganges-Brahmaputra rivers, this study presents records of post-glacial changes in basin-scale Indian summer monsoon intensity and vegetation composition based on stable hydrogen (δD) and carbon (δ13C) isotopic compositions of terrestrial plant wax compounds preserved in the channel-levee system of the Bengal Fan. It then explores the role of these changes in controlling the provenance and degree of chemical weathering of sediments exported by these rivers, and the potential climate feedbacks through organic-carbon burial in the Bengal Fan. An observed 40‰ shift in δD and a 3-4‰ shift in both bulk organic-carbon and plant-wax δ13C values between the late glacial and mid-Holocene, followed by a return to more intermediate values during the late Holocene, correlates well with regional post-glacial paleoclimate records. Sediment provenance proxies (Sr, Nd isotopic compositions) reveal that these changes likely coincided with a subtle focusing of erosion on the southern flank of the Himalayan range during periods of greater monsoon strength and enhanced sediment discharge. However, grain-size-normalized organic-carbon concentrations in the Bengal Fan remained constant through time, despite order-of-magnitude level changes in catchment-scale monsoon precipitation and enhanced chemical weathering (recorded as a gradual increase in K/Si* and detrital carbonate content, and decrease in H2O+/Si*, proxies) throughout the study period. These findings demonstrate a partial decoupling of climate change and silicate weathering during the Holocene and that marine organic-carbon sequestration rates primary reflect rates of physical erosion and sediment export

  14. High Resolution Audiomagnetotelluric Investigation of the Porosity at the Margin of the Hudson Bay Basin, Canada

    Science.gov (United States)

    Craven, J. A.; Roberts, B.

    2012-12-01

    Seismic exploration from 1968 to 1985 within the intracratonic Hudson Bay basin in northern Canada resulted in five dry wells drilled on a structural high in the central part of the basin (Hamblin, 2008). Recent work (Bertrand and Malo, 2012) has indicated successions at margins of the basin are well within the oil and gas "window". To test this conjecture a magnetotelluric (MT) survey was carried out in the vicinity of Churchill, Manitoba, at the margin of the basin. The primary goal of the survey was to identify potential source or reservoir rocks in the Upper Ordovician section of the Palaeozoic strata. MT surveys have been utilized in the northeastern portion of the Williston basin and have successfully imaged lower Palaeozoic carbonate units (Gowan et al., 2009). The MT method provides information on the electrical conductivity of the subsurface though the measurement of the natural time-varying electric and magnetic fields at the surface. Due to the dependence of the depth of investigation of the fields on their frequency, an estimate of conductivity variation with depth can be attained. A total of 46 high frequency audio-magnetotelluric (AMT) sites were collected, 38 along one approximately N-S corridor perpendicular to the coastline and 8 in a more E-W direction closer to the town of Churchill. Simultaneous collection of broadband MT data (BBMT) at a limited number of sites was done in order to calculate a response function over a wider range of frequencies at each AMT site. The combined AMT and BBMT MT data have been edited and processed to produce response functions at all sites, and 1-D modelling has provided resistivity vs. depth curves in the top 200 m of the basin. The 1-D models have been stitched together to create a continuous, approximately N-S resistivity section. In addition, the data have been input to a 3D inversion program and preliminary 3D resistivity and conductivity volumes have been generated along with an estimate of 3-D porosity

  15. Sedimentary characteristics of carbonate intra-platform shoals and their formation in Ordovician Tarim Basin, West China

    Science.gov (United States)

    Meng, M.

    2015-12-01

    The widely distributed carbonate intra-platform shoals has become a new important exploration target within the Tarim Basin, where reservoirs of Yubei oil-field (discovered in 2011) and the Shunnan oil-field (discovered in 2013) occur. Better understanding of the sedimentary characteristics and formation of intra-platform shoals is significant for predicting the distribution of Ordovician shoal reservoirs. The sedimentary characteristics, distribution patterns and formation mechanisms of carbonate intra-platform shoals in Ordovician Tarim Basin were studied based on outcrop analogue, core data, thin section observation, seismic, and well log data. Those shoals include oolitic shoal, intraclast shoal and bioclastic shoal. The intra-platform shoal consists of three sedimentary units: shoal base, shoal core and shoal cover, which are adjacent to intershoal sea faces. Laterally, the intra-platform shoals occurred as a more continuous sheet-like body.The intra-platform shoals deposited mainly in the lowstand systems tract and late stage of highstand systems tract. Several factors were probably responsible for the occurrence of intra-platform shoals, including: (i) a relatively shallow-water condition with a strong hydrodynamic environment, (ii) high-frequency oscillations of the sea level, and (iii) Subtle paleo-highs and relatively weak structural activities, which are important for the spatial distribution of reservoir facies.

  16. Dry season limnological conditions and basin geology exhibit complex relationships with δ13C and δ15N of carbon sources in four Neotropical floodplains

    Science.gov (United States)

    Hoeinghaus, David J.; Manetta, Gislaine I.; Benedito, Evanilde

    2017-01-01

    Studies in freshwater ecosystems are seeking to improve understanding of carbon flow in food webs and stable isotopes have been influential in this work. However, variation in isotopic values of basal production sources could either be an asset or a hindrance depending on study objectives. We assessed the potential for basin geology and local limnological conditions to predict stable carbon and nitrogen isotope values of six carbon sources at multiple locations in four Neotropical floodplain ecosystems (Paraná, Pantanal, Araguaia, and Amazon). Limnological conditions exhibited greater variation within than among systems. δ15N differed among basins for most carbon sources, but δ13C did not (though high within-basin variability for periphyton, phytoplankton and particulate organic carbon was observed). Although δ13C and δ15N values exhibited significant correlations with some limnological factors within and among basins, those relationships differed among carbon sources. Regression trees for both carbon and nitrogen isotopes for all sources depicted complex and in some cases nested relationships, and only very limited similarity was observed among trees for different carbon sources. Although limnological conditions predicted variation in isotope values of carbon sources, we suggest the resulting models were too complex to enable mathematical corrections of source isotope values among sites based on these parameters. The importance of local conditions in determining variation in source isotope values suggest that isotopes may be useful for examining habitat use, dispersal and patch dynamics within heterogeneous floodplain ecosystems, but spatial variability in isotope values needs to be explicitly considered when testing ecosystem models of carbon flow in these systems. PMID:28358822

  17. Dry season limnological conditions and basin geology exhibit complex relationships with δ13C and δ15N of carbon sources in four Neotropical floodplains.

    Science.gov (United States)

    Zaia Alves, Gustavo H; Hoeinghaus, David J; Manetta, Gislaine I; Benedito, Evanilde

    2017-01-01

    Studies in freshwater ecosystems are seeking to improve understanding of carbon flow in food webs and stable isotopes have been influential in this work. However, variation in isotopic values of basal production sources could either be an asset or a hindrance depending on study objectives. We assessed the potential for basin geology and local limnological conditions to predict stable carbon and nitrogen isotope values of six carbon sources at multiple locations in four Neotropical floodplain ecosystems (Paraná, Pantanal, Araguaia, and Amazon). Limnological conditions exhibited greater variation within than among systems. δ15N differed among basins for most carbon sources, but δ13C did not (though high within-basin variability for periphyton, phytoplankton and particulate organic carbon was observed). Although δ13C and δ15N values exhibited significant correlations with some limnological factors within and among basins, those relationships differed among carbon sources. Regression trees for both carbon and nitrogen isotopes for all sources depicted complex and in some cases nested relationships, and only very limited similarity was observed among trees for different carbon sources. Although limnological conditions predicted variation in isotope values of carbon sources, we suggest the resulting models were too complex to enable mathematical corrections of source isotope values among sites based on these parameters. The importance of local conditions in determining variation in source isotope values suggest that isotopes may be useful for examining habitat use, dispersal and patch dynamics within heterogeneous floodplain ecosystems, but spatial variability in isotope values needs to be explicitly considered when testing ecosystem models of carbon flow in these systems.

  18. Assessment of the redistribution of soil carbon using a new index--a case study in the Haihe River Basin, North China.

    Science.gov (United States)

    Ji, Yuhe; Chen, Liding; Zhou, Guangsheng; Sun, Ranhao; Shang, Linyuan; Wang, Shudong

    2014-11-01

    Soil carbon redistribution is an important process in the terrestrial carbon cycle. This study describes a new index, soil carbon redistribution (SCR) index, that can be used to assess long-term soil carbon redistribution at a large watershed scale. The new index is based on the theoretical preconditions that soil carbon redistribution is mainly controlled by vegetation type, precipitation, topography/slope, and soil carbon concentration. The Haihe River Basin served as an example for this analysis. The SCR index was calculated, and a GIS-based map shows its spatial patterns. The results suggested that soil carbon was usually prone to being carried away from mountainous regions with natural vegetation, while it was prone to deposition in the plain and plateau regions with cultivated vegetation. The methods in the paper offer a tool that can be used to quantify the potential risk where soil carbon is prone to being carried away and deposited in a large watershed.

  19. Qualitative and Quantitative Changes of Carbonate Rocks Exposed to SC CO2 (Basque-Cantabrian Basin, Northern Spain

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    Edgar Berrezueta

    2017-11-01

    Full Text Available This study aims at the qualitative and quantitative determination of porosity, mineralogical and textural changes in carbonate rock samples after injection of (i supercritical CO2-rich brine and (ii dry supercritical CO2, under similar experimental conditions (P ≈ 75 bar, T ≈ 35 °C, 970 h exposure time and no CO2 flow. The studied rocks were sampled in the western Basque-Cantabrian Basin, North Spain, and consist of vuggy carbonates (“Carniolas” of the Puerto de la Palombera formation (Hettangian. Mineralogical and pore space characterization is completed using optical microscopy, scanning electron microscopy and optical image analysis. In addition, X-ray fluorescence analyses are performed to refine the mineralogical information and to obtain whole rock geochemical data and the brine composition is analysed before and after the experiment. Mineralogical and chemical results indicate that the carbonate rocks exposed to supercritical CO2 in dry conditions do not suffer significant changes. However, the injection of supercritical CO2-rich brine induces chemical and physical changes in the rock due to the high reactivity of calcite at the low pH conditions produced by the acidified brine. Numerical modelling validates the experimental observations. These results can be used to characterize the behaviour of carbonate rocks under conditions similar to the vicinity of a CO2 injection well. The results should be considered only at the scale of the studied samples and not at reservoir scale.

  20. Influences of glacial melt and permafrost thaw on the age of dissolved organic carbon in the Yukon River basin

    Science.gov (United States)

    Aiken, George R.; Spencer, Robert G.M.; Striegl, Robert G.; Schuster, Paul F.; Raymond, Peter A.

    2014-01-01

    Responses of near-surface permafrost and glacial ice to climate change are of particular significance for understanding long-term effects on global carbon cycling and carbon export by high-latitude northern rivers. Here we report Δ14C-dissolved organic carbon (DOC) values and dissolved organic matter optical data for the Yukon River, 15 tributaries of the Yukon River, glacial meltwater, and groundwater and soil water end-member sources draining to the Yukon River, with the goal of assessing mobilization of aged DOC within the watershed. Ancient DOC was associated with glacial meltwater and groundwater sources. In contrast, DOC from watersheds dominated by peat soils and underlain by permafrost was typically enriched in Δ14C indicating that degradation of ancient carbon stores is currently not occurring at large enough scales to quantitatively influence bulk DOC exports from those landscapes. On an annual basis, DOC exported was predominantly modern during the spring period throughout the Yukon River basin and became older through summer-fall and winter periods, suggesting that contributions of older DOC from soils, glacial meltwaters, and groundwater are significant during these months. Our data indicate that rapidly receding glaciers and increasing groundwater inputs will likely result in greater contributions of older DOC in the Yukon River and its tributaries in coming decades.

  1. Site Development, Operations, and Closure Plan Topical Report 5 An Assessment of Geologic Carbon Sequestration Options in the Illinois Basin. Phase III

    Energy Technology Data Exchange (ETDEWEB)

    Finley, Robert [Univ. of Illinois, Champaign, IL (United States); Payne, William [Schlumberger Carbon Services, Houston, TX (United States); Kirksey, Jim [Univ. of Illinois, Champaign, IL (United States)

    2015-06-01

    The Midwest Geological Sequestration Consortium (MGSC) has partnered with Archer Daniels Midland Company (ADM) and Schlumberger Carbon Services to conduct a large-volume, saline reservoir storage project at ADM’s agricultural products processing complex in Decatur, Illinois. The Development Phase project, named the Illinois Basin Decatur Project (IBDP) involves the injection of 1 million tonnes of carbon dioxide (CO2) into a deep saline formation of the Illinois Basin over a three-year period. This report focuses on objectives, execution, and lessons learned/unanticipated results from the site development (relating specifically to surface equipment), operations, and the site closure plan.

  2. Eocene-Miocene carbon-isotope and floral record from brown coal seams in the Gippsland Basin of southeast Australia

    Science.gov (United States)

    Holdgate, Guy R.; McGowran, Brian; Fromhold, Tom; Wagstaff, Barbara E.; Gallagher, Stephen J.; Wallace, Malcolm W.; Sluiter, Ian R. K.; Whitelaw, Michael

    2009-01-01

    The carbon-isotope and palynological record through 580 m thick almost continuous brown coal in southeast Australia's Gippsland Basin is a relatively comprehensive southern hemisphere Middle Eocene to Middle Miocene record for terrestrial change. The carbon isotope δ 13C coal values of these coals range from - 27.7‰ to - 23.2. This isotopic variability follows gymnosperm/angiosperm fluctuations, where higher ratios coincide with heavier δ13C values. There is also long-term variability in carbon isotopes through time. From the Eocene greenhouse world of high gymnosperm-heavier δ13C coal values, there is a progressive shift to lighter δ13C coal values that follows the earliest (Oi1?) glacial events around 33 Ma (Early Oligocene). The overlying Oligocene-Early Miocene brown coals have lower gymnosperm abundance, associated with increased % Nothofagus (angiosperm), and lightening of isotopes during Oligocene cooler conditions. The Miocene palynological and carbon-isotope record supports a continuation to the Oligocene trends until around the late Early Miocene (circa 19 Ma) when a warming commenced, followed by an even stronger isotope shift around 16 Ma that peaked in the Middle Miocene when higher gymnosperm abundance and heavier isotopes prevailed. The cycle between the two major warm peaks of Middle Eocene and Middle Miocene was circa 30 Ma long. This change corresponds to a fall in inferred pCO 2 levels for the same period. The Gippsland data suggest a link between gymnosperm abundance, long-term plant δ13C composition, climatic change, and atmospheric pCO 2. Climatic deterioration in the Late Miocene terminated peat accumulation in the Gippsland Basin and no further significant coals formed in southeast Australia. The poor correspondence between this terrestrial isotope data and the marine isotope record is explained by the dominant control on δ13C by the gymnosperm/angiosperm abundance, although in turn this poor correspondence may reflect palaeoclimate

  3. Porosity and Permeability Development of the Deep-Water Late-Oligocene Carbonate Debris Reservoir in the Surroundings of the Paternoster Platform, South Makassar Basin, Indonesia

    Directory of Open Access Journals (Sweden)

    Gadjah E. Pireno

    2015-12-01

    Full Text Available The discovery of gas within the carbonate debris reservoir of the late Oligocene Berai formation near the Paternoster Platform, South Makassar Basin, is a new exploration play in Indonesia. The carbonate was deposited in a deep-water environment and is a good example of a less well known carbonate play type. The carbonate debris reservoir in this area consists of re-deposited carbonate, originally located on a large carbonate platform that has been eroded, abraded and transported to the deep-water sub-basin. The limestone clasts range from pebble-size to boulders within a matrix of micrite and fine abraded bioclasts. This carbonate debris can be divided into clast-supported facies and matrix-supported facies. The matrix-supported facies have much better porosity and permeability than the clast-supported facies. Porosity in both the transported clasts and the matrix is generally mouldic and vuggy, resulting mostly from dissolution of foraminifera and other bioclastics after transportation. In the matrix intercrystal porosity has developed. The porosity and permeability development of this deep-water carbonate debris was controlled by a deep-burial diagenetic process contributed by the bathyal shales de-watering from the Lower Berai shales beneath the carbonate reservoir and the Lower Warukin shales above the carbonate reservoir during the burial process.

  4. Early Triassic fluctuations of the global carbon cycle: New evidence from paired carbon isotopes in the western USA basin

    Science.gov (United States)

    Caravaca, Gwénaël; Thomazo, Christophe; Vennin, Emmanuelle; Olivier, Nicolas; Cocquerez, Théophile; Escarguel, Gilles; Fara, Emmanuel; Jenks, James F.; Bylund, Kevin G.; Stephen, Daniel A.; Brayard, Arnaud

    2017-07-01

    In the aftermath of the catastrophic end-Permian mass extinction, the Early Triassic records recurrent perturbations in the carbon isotope signal, most notably during the Smithian and through the Smithian/Spathian Boundary (SSB; 1.5 myr after the Permian/Triassic boundary), which show some of the largest excursions of the Phanerozoic. The late Smithian also corresponds to major biotic turnovers and environmental changes, such as temperature fluctuations, that deeply impacted the recovery after the end-Permian mass extinction. Here we document the paired carbon isotope signal along with an analysis of the trace and major elements at the long-known Hot Springs section (southeastern Idaho, USA). This section records Early Triassic sediments from the Griesbachian-Dienerian up to the lower Spathian. We show that the organic and carbonate δ13C variations mirror the signals identified at a global scale. Particularly, the middle Smithian-SSB event represented by a negative-positive isotopic couplet is well identified and is not of diagenetic origin. We also document a positive excursion potentially corresponding to the Dienerian/Smithian Boundary. Observed Smithian-Spathian excursions are recorded similarly in both the organic and carbonate reservoirs, but the organic matter signal systematically shows unexpectedly dampened variations compared to its carbonate counterpart. Additionally, we show that variations in the net isotopic effect (i.e., Δ13C) probably resulted from a complex set of forcing parameters including either a mixing between terrestrial and marine organic matter depending on the evolution of the depositional setting, or variations in the biological fractionation. We establish that the Δ13C signal cannot be directly related to CO2-driven temperature variations at Hot Springs. Even though the carbon isotope signal mirrors the Early Triassic variations known at the global scale, the Hot Springs signal probably also reflects local influences on the carbon

  5. Chemical Weathering in the Zambesi Basin: Assesment of the Carbon Dioxyde Comsumption by the Karu Basalt Province

    Science.gov (United States)

    Seyler, P. T.; Viers, J.; Aries, S.; Fournier, P.

    2014-12-01

    The quantification of the role of weathering in the carbon cycle and its interaction with climate and tectonics at the geological time scale is one of the key questions of the geoscientists. The consumption of atmospheric CO2 by silicate weathering indisputably plays the central role in the long term carbon budget and consequently on mean global climate. Through the composition of major elements in river waters, CO2 consumption by the alteration of continental rocks can be estimated. The aim of this study is to estimate of the chemical weathering rate of the Zambesi basin and the impact of Karoo basalt province on chemical atmospheric consumption, evaluated from a database of major elements. The Karroo basalts outcrop erupted around 183 +/2 2 106 take place in the Upper and the Middle Zambezi, covering a surface of 9600 km2. The Zambesi Basin, located between 8° and 20° south latitude and between 16.5 and 36 east longitude, is the fourth largest in Africa. The catchment has a total area of some 1,281,000 km2, the mean annual temperature is 19,3°C and the annual rainfall varies from nearly 2 000 mm to 600 mm. During the sampling period, the annual runoff at Victoria Fall gauging Station ranged between 50 to 2000 m3/s ie 6.9 to 0.6 l/s/km2. The consumption rate of atmospheric CO2 associated with the chemical weathering was calculated from riverine HCO3- concentrations. During the weathering of volcanic rocks, all dissolved carbonates originate from atmospheric/sil CO2. Values of CO2 consumption rates are relatively high, about 0.024 1012 mol/yr, and are comparable to Deccan Traps consumption rates.

  6. Carbon and oxygen isotopic constraints on paleoclimate and paleoelevation of the southwestern Qaidam basin, northern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Lin-Lin Li

    2017-09-01

    Full Text Available We investigate the growth of the northern Tibetan Plateau and associated climate change by applying oxygen and carbon isotopic compositions in Cenozoic strata in the southwestern Qaidam basin. The X-ray diffraction and isotopic studies reveal that the carbonate minerals are mainly authigenic and they do not preserve any evidence for detrital carbonate and diagenesis. The isotope data show large fluctuations in the δ18O and δ13C values in the middle–late Eocene, indicating relatively warm and seasonal dry climate. The positive correlation of the δ18O and δ13C values in the Oligocene and the positive shift of the δ13C values from the Eocene to Oligocene suggest that the climate changed to arid in the Oligocene. However, the δ18O values show negative shift, which is closely related to the global cooling event. During the Miocene, the δ13C values vary between –2‰ and –4‰, whereas the δ18O values show continuous negative shift. The mean δ18O values decrease from –8.5‰ in the early Miocene to –10.0‰ in the late Miocene. The stable isotope-based paleoaltimetry results suggest that the elevation of the southwestern Qaidam basin was approximately 1500 m in the middle–late Eocene and Oligocene. Subsequently, during Miocene the crustal uplift process started and the elevation reached approximately 2000 m in the early Miocene and 2500 m in the late Miocene, which suggests large-scale growth of the northern Tibet Plateau during the Miocene.

  7. Pedogenic carbonate stable isotopic evidence for wooded habitat preference of early Pleistocene tool makers in the Turkana Basin.

    Science.gov (United States)

    Quinn, Rhonda L; Lepre, Christopher J; Feibel, Craig S; Wright, James D; Mortlock, Richard A; Harmand, Sonia; Brugal, Jean-Philip; Roche, Hélène

    2013-07-01

    The origin and evolution of early Pleistocene hominin lithic technologies in Africa occurred within the context of savanna grassland ecosystems. The Nachukui Formation of the Turkana Basin in northern Kenya, containing Oldowan and Acheulean tool assemblages and fossil evidence for early members of Homo and Paranthropus, provides an extensive spatial and temporal paleosol record of early Pleistocene savanna flora. Here we present new carbon isotopic (δ(13)CVPDB) values of pedogenic carbonates (68 nodules, 193 analyses) from the Nachukui Formation in order to characterize past vegetation structure and change through time. We compared three members (Kalochoro, Kaitio, and Natoo) at five locations spanning 2.4-1.4Ma and sampled in proximity to hominin archaeological and paleontological sites. Our results indicate diverse habitats showing a mosaic pattern of vegetation cover at each location yet demonstrate grassland expansion through time influenced by paleogeography. Kalochoro floodplains occurred adjacent to large river systems, and paleosols show evidence of C3 woodlands averaging 46-50% woody cover. Kaitio habitats were located along smaller rivers and lake margins. Paleosols yielded evidence for reduced portions of woody vegetation averaging 34-37% woody cover. Natoo environments had the highest percentage of grasslands averaging 21% woody cover near a diminishing Lake Turkana precursor. We also compared paleosol δ(13)CVPDB values of lithic archaeological sites with paleosol δ(13)CVPDB values of all environments available to hominins at 2.4-1.4Ma in the Nachukui and Koobi Fora Formations. Grassy environments became more widespread during this interval; woody canopy cover mean percentages steadily decreased by 12%. However, significantly more wooded savanna habitats were present in the vicinity of lithic archaeological sites and did not mirror the basin-wide trend of grassland spread. Hominin lithic archaeological sites consistently demonstrated woody cover

  8. Origin of the groundwater salinity and geochemical processes in detrital and carbonate aquifers: Case of Chougafiya basin (Central Tunisia)

    Science.gov (United States)

    Farid, Intissar; Zouari, Kamel; Rigane, Adel; Beji, Ridha

    2015-11-01

    Comprehensive investigations of groundwaters were performed in the detrital and carbonate aquifers of the Chougafiya basin, central Tunisia. In the present review, hydrochemistry and isotopic tools were combined to get an insight into the processes controlling mineralization, recharge conditions, flow pattern of groundwater and C chemistry in the investigated hydrological system. Analysis of the dissolved constituents revealed that several processes controlled the observed chemical composition: (i) the dissolution of evaporitic minerals, (ii) cation exchange reactions, (iii) sulfate reduction under anaerobic conditions, (iv) incongruent dissolution of carbonate minerals (calcite, dolomite) coupled with gypsum dissolution and calcite precipitation, and (v) silicates weathering. Data inferred from 18O and deuterium isotopes in groundwater samples indicated recharge with modern rainfall. Water characterized by lower δ18O and δ2H values is interpreted as recharged by non-evaporated rainfall originating from Mediterranean and Atlantic air masses. However, water with relatively enriched δ18O and δ2H contents is thought to reflect the occurrence of an evaporation process related to the long term practice of flood irrigation. The radiogenic (3H) isotope data provided insight into the presence of two recharge periods in the investigated groundwaters. Waters with 3H contents of 1 TU clearly suggested the occurrence of a contemporaneous recharge probably during the last two decades. Carbon isotopes provided some insights into the timescales of groundwater flow, but mainly revealed that main sources of C are active in the system. These are likely: dissolved biogenic CO2, carbonate dissolution and incongruent reaction of the carbonate matrix. Mean residence times were determined after correction of the initial activities for dead C from the rock matrix and suggest ages ranging from the present day to the Holocene in both Upper Cretaceous and Mio-pliocene groundwaters.

  9. Organic carbon in floodplain alluvium: Signature of historic variations in erosion processes associated with deforestation, Waipaoa River basin, New Zealand

    Science.gov (United States)

    Gomez, Basil; Brackley, Hannah L.; Hicks, D. Murray; Neff, Hector; Rogers, Karyne M.

    2004-12-01

    We use C-org and δ13C to trace the origin of the alluvium deposited on the Waipaoa River floodplain at McPhail's Bend between 1853 and 2002. The overbank deposits exhibit a more positive range of δ13C values (-26.3 ± 0.6) than contemporary suspended sediment in transport at intermediate flows (-27.8 ± 0.2) when gully erosion releases most material to stream channels, reflecting the greater contribution made by shallow landsliding in the headwaters during large precipitation events. Overbank sediment associated with recent floods contains a higher (˜50%) amount of organic carbon than alluvium deposited by pre-1927 floods, which was derived from outcrops of weathered bedrock on steep, riparian hillslopes that were the primary sediment source before the soil-mantled hillslopes elsewhere in the headwaters of the basin were destabilized by deforestation. The recent alluvium resembles the Bw horizon of soils present on these hillslopes. Sediment deposited during floods generated by localized storms and an overbank event that did not feature widespread shallow landsliding also has a distinctive signature that provides an indication of its provenance. The organic carbon associated with the alluvium appears to be old (4031 ± 40 B.P., in the case of the carbon associated with sediment deposited in 2002) and to be derived from weathered Cretaceous and Tertiary sedimentary rocks.

  10. Decadal change of forest biomass carbon stocks and tree demography in the Delaware River Basin

    Science.gov (United States)

    Bing Xu; Yude Pan; Alain F. Plante; Arthur Johnson; Jason Cole; Richard Birdsey

    2016-01-01

    Quantifying forest biomass carbon (C) stock change is important for understanding forest dynamics and their feedbacks with climate change. Forests in the northeastern U.S. have been a net carbon sink in recent decades, but C accumulation in some northern hardwood forests has been halted due to the impact of emerging stresses such as invasive pests, land use change and...

  11. 3D depositional architecture of a non-tropical carbonate shelf, Eocene-Oligocene, Browse Basin (NW Australia)

    Science.gov (United States)

    Reuning, L.; Back, S.; Schulz, H.; Hirsch, M.; Kukla, P. A.; Grötsch, J.

    2009-04-01

    Calciclastic gravity-flow deposits accumulated on continental margins can form potentially very important and attractive targets for hydrocarbon exploration. A correct reservoir characterization of calciclastic slope deposits needs a robust understanding of their sedimentary facies and three-dimensional depositional architecture. Conventional 2D grids often lead to a spatial aliasing whenever the size of submarine gullies and canyons is less than the spacing of the grid. In contrast, high-resolution 3D seismic data are ultimately comparable in resolution to those achieved by multi-beam bathymetry of the present seafloor. Seismic data from the western part of the Browse Basin, North West Shelf, Australia, reveal the internal geometry and depositional history of a progradational Eocene-Oligocene non-tropical carbonate shelf. The prograding slope system is superbly imaged by two adjacent, three-dimensional multichannel seismic volumes embedded in a two-dimensional multichannel seismic grid. Based on this data, the three-dimensional stratal architecture of prograding clinoforms can be mapped throughout an area of ~ 1000 km2. During progradation the carbonate slope system develops from a distally steepend carbonate ramp with a linear to sigmoidal slope curvature to a carbonate platform with a concave-upward slope morphology. This change in slope morphology is accompanied by a change in the erosion pattern on the clinoform fronts. The submarine canyons of the linear to sigmoidal slope reach a total length between 7 and 15 km, and their width, measured perpendicular to the flow direction, varies between 1.2 km and 0.6 km. In contrast, the concave-upward slope is characterized by relatively smooth foresets, which are dissected by relatively small gullies. The numerous submarine channels on both slope types define a line-sourced system which develops a sedimentary apron along the carbonate ramp. The relatively high sinuosity of some of the channels is not known from

  12. The Origin of Carbon-bearing Volatiles in Surprise Valley Hot Springs in the Great Basin: Carbon Isotope and Water Chemistry Characterizations

    Science.gov (United States)

    Fu, Qi; Socki, Richard A.; Niles, Paul B.; Romanek, Christopher; Datta, Saugata; Darnell, Mike; Bissada, Adry K.

    2013-01-01

    There are numerous hydrothermal fields within the Great Basin of North America, some of which have been exploited for geothermal resources. With methane and other carbon-bearing compounds being observed, in some cases with high concentrations, however, their origins and formation conditions remain unknown. Thus, studying hydrothermal springs in this area provides us an opportunity to expand our knowledge of subsurface (bio)chemical processes that generate organic compounds in hydrothermal systems, and aid in future development and exploration of potential energy resources as well. While isotope measurement has long been used for recognition of their origins, there are several secondary processes that may generate variations in isotopic compositions: oxidation, re-equilibration of methane and other alkanes with CO2, mixing with compounds of other sources, etc. Therefore, in addition to isotopic analysis, other evidence, including water chemistry and rock compositions, are necessary to identify volatile compounds of different sources. Surprise Valley Hot Springs (SVHS, 41 deg 32'N, 120 deg 5'W), located in a typical basin and range province valley in northeastern California, is a terrestrial hydrothermal spring system of the Great Basin. Previous geophysical studies indicated the presence of clay-rich volcanic and sedimentary rocks of Tertiary age beneath the lava flows in late Tertiary and Quaternary. Water and gas samples were collected for a variety of chemical and isotope composition analyses, including in-situ pH, alkalinity, conductivity, oxidation reduction potential (ORP), major and trace elements, and C and H isotope measurements. Fluids issuing from SVHS can be classified as Na-(Cl)-SO4 type, with the major cation and anion being Na+ and SO4(2-), respectively. Thermodynamic calculation using ORP and major element data indicated that sulfate is the most dominant sulfur species, which is consistent with anion analysis results. Aquifer temperatures at depth

  13. The Origin of Carbon-bearing Volatiles in Surprise Valley Hot Springs in the Great Basin: Carbon Isotope aud Water Chemistry Characterizations

    Science.gov (United States)

    Fu, Qi; Socki, Richard A.; Niles, Paul B.; Romanek, Christopher; Datta, Saugata; Darnell, Mike; Bissada, Adry K.

    2013-01-01

    There are numerous hydrothermal fields within the Great Basin of North America, some of which have been exploited for geothermal resources. With methane and other carbon-bearing compounds being observed, in some cases with high concentrations, however, their origins and formation conditions remain unknown. Thus, studying hydrothermal springs in this area provides us an opportunity to expand our knowledge of subsurface (bio)chemical processes that generate organic compounds in hydrothermal systems, and aid in future development and exploration of potential energy resources as well. While isotope measurement has long been used for recognition of their origins, there are several secondary processes that may generate variations in isotopic compositions: oxidation, re-equilibration of methane and other alkanes with CO2, mixing with compounds of other sources, etc. Therefore, in addition to isotopic analysis, other evidence, including water chemistry and rock compositions, are necessary to identify volatile compounds of different sources. Surprise Valley Hot Springs (SVHS, 41º32'N, 120º5'W), located in a typical basin and range province valley in northeastern California, is a terrestrial hydrothermal spring system of the Great Basin. Previous geophysical studies indicated the presence of clay-rich volcanic and sedimentary rocks of Tertiary age beneath the lava flows in late Tertiary and Quaternary. Water and gas samples were collected for a variety of chemical and isotope composition analyses, including in-situ pH, alkalinity, conductivity, oxidation reduction potential (ORP), major and trace elements, and C and H isotope measurements. Fluids issuing from SVHS can be classified as Na-(Cl)-SO4 type, with the major cation and anion being Na+ and SO4 2-, respectively. Thermodynamic calculation using ORP and major element data indicated that sulfate is the most dominant sulfur species, which is consistent with anion analysis results. Aquifer temperatures at depth estimated

  14. Two-dimensional simulation of clastic and carbonate sedimentation, consolidation, subsidence, fluid flow, heat flow and solute transport during the formation of sedimentary basins

    Science.gov (United States)

    Bitzer, Klaus

    1999-05-01

    Geological processes that create sedimentary basins or act during their formation can be simulated using the public domain computer code `BASIN'. For a given set of geological initial and boundary conditions the sedimentary basin evolution is calculated in a forward modeling approach. The basin is represented in a two-dimensional vertical cross section with individual layers. The stratigraphic, tectonic, hydrodynamic and thermal evolution is calculated beginning at an initial state, and subsequent changes of basin geometry are calculated from sedimentation rates, compaction and pore fluid mobilization, isostatic compensation, fault movement and subsidence. The sedimentologic, hydraulic and thermal parameters are stored at discrete time steps allowing the temporal evolution of the basin to be analyzed. A maximum flexibility in terms of geological conditions is achieved by using individual program modules representing geological processes which can be switched on and off depending on the data available for a specific simulation experiment. The code incorporates a module for clastic and carbonate sedimentation, taking into account the impact of clastic sediment supply on carbonate production. A maximum of four different sediment types, which may be mixed during sedimentation, can be defined. Compaction and fluid flow are coupled through the consolidation equation and the nonlinear form of the equation of state for porosity, allowing nonequilibrium compaction and overpressuring to be calculated. Instead of empirical porosity-effective stress equations, a physically consistent consolidation model is applied which incorporates a porosity dependent sediment compressibility. Transient solute transport and heat flow are calculated as well, applying calculated fluid flow rates from the hydraulic model. As a measure for hydrocarbon generation, the Time-Temperature Index (TTI) is calculated. Three postprocessing programs are available to provide graphic output in Post

  15. An Evaluation of the Carbon Sequestration Potential of the Cambro-Ordovician Strata of the Illinois and Michigan Basins

    Energy Technology Data Exchange (ETDEWEB)

    Kirksey, Jim; Ansari, Sajjad; Malkewicz, Nick; Leetaru, Hannes

    2014-01-01

    The Knox Supergroup is a significant part of the Cambrian-Ordovician age sedimentary deposition in the Illinois Basin. While there is a very small amount of oil production associated with the upper Knox, it is more commonly used as a zone for both Class I and Class II disposal wells in certain areas around the state. Based on the three penetrations of the Knox Formation at the Illinois Basin – Decatur Project (IBDP) carbon dioxide (CO2) sequestration site in Macon County, Illinois, there is potential for certain zones in the Knox to be used for CO2 sequestration. More specifically, the Potosi member of the Knox Formation at about –3,670 feet (ft) subsea depth would be a candidate as all three penetrations had massive circulation losses while drilling through this interval. Each well required the setting of cement plugs to regain wellbore stability so that the intermediate casing could be set and successfully cemented to surface. Log and core analysis suggests significant karst porosity throughout the Potosi member. The purpose of this study is to develop a well plan for the drilling of a CO2 injection well with the capability to inject 3.5 million tons per annum (3.2 million tonnes per annum [MTPA] CO2 into the Knox Formation over a period of 30 years.

  16. Furongian Stable Carbon Isotope Excursions (SPICE and HERB) in the Mixed Carbonate-Siliclastics on an Epeiric Platform of the Taebaeksan Basin, Korea

    Science.gov (United States)

    Chung, G. S.; Lim, J. N.; Park, T. Y.; Lee, K. S.; Lee, B. S.; Seo, K. S.

    2014-12-01

    Stable carbon isotope stratigraphy of the Late Cambrian mixed carbonate-siliciclastics from an epeiric platform allows a good stratigraphic marker and interpretation of paleoenvironmental conditions. The SPICE (Steptoean positive carbon excursion) and HERB (Hellnmaria-Red Tops Boundary) events are distinctly developed in the Furongian (Late Cambrian) of mixed carbonate-siliciclastics (Sesong and Hwajeol Formations) deposited on an epeiric platform of the Taebaeksan Basin, Korea, part of the North China Platform. The SPICE event occurs in the Prochuangia mansuyi zone and in the lower part of Chuangia zone of trilobite in the Sesong Formation with the δ13C values ranging from 1.1 to 1.8‰; it occurs in the stratigraphic interval mostly composed of nodular shale, massive to laminated fine sandstone with intercalation of limestone conglomerate beds which is interpreted to have been deposited in the inner to middle ramp. The HERB event begins at about the Eoconodontus notchpeakensis FAD of conodont and ends in the lower part of the range of E. notchpeakensis in the Hwajeol Formation. The HERB event shows negative δ13C values up to -5.5‰ forming a conspicuous and distinctive peak. The HERB event occurs in the stratigraphic interval mostly composed of nodular shale, limestone-shale couplet, and limestone conglomerate which is interpreted to have been deposited in the middle ramp. The onset of HERB event at the E. notchpeakensis FAD in the Taebaeksan basin, Korea suggests that the HERB event may be an excellent tool for intercontinental correlation defining the base of the terminal Cambrian (Stage 10). The paleoenvironmental conditions of the SPICE and HERB events seem to be contrary to each other; the SPICE event may be caused by the high rate of primary production and the high rate burial of organic matter with probable association of the high rate of input of terrigenous sediments. In contrast, the HERB event may be caused by the low rate of primary productivity

  17. Uncertainty assessment in the stratigraphic well correlation of a carbonate ramp: Method and application to the Beausset Basin, SE France

    Science.gov (United States)

    Lallier, Florent; Caumon, Guillaume; Borgomano, Jean; Viseur, Sophie; Royer, Jean-Jacques; Antoine, Christophe

    2016-09-01

    We assess stratigraphic correlation uncertainties by stochastically generating several possible correlations lines between a set of stratigraphic logs. We motivate the use of automatic correlation methods to sample this uncertainty and introduce a stochastic version of Dynamic Time Warping (DTW) that correlates two logs. This method is extended to a larger number of logs using a sequential application of DTW. When available, low-frequency stratigraphic events are correlated first, and then used to constrain the correlation of higher-order events. All DTW variants use elementary correlation costs corresponding to the likelihood of each possible horizon. The method is demonstrated on a carbonate ramp of the Cretaceous southern Provence Basin, SE France, using costs that measure the consistency between the computed platform slope angle and a theoretical depositional profile. We show that these correlation uncertainties significantly impact facies proportions in stratigraphic layers.

  18. Evaluation of carbon fluxes and trends (2000-2008) in the Greater Platte River Basin: a sustainability study on the potential biofuel feedstock development

    Science.gov (United States)

    Gu, Yingxin; Wylie, Bruce K.; Zhang, Li; Gilmanov, Tagir G.

    2012-01-01

    This study evaluates the carbon fluxes and trends and examines the environmental sustainability (e.g., carbon budget, source or sink) of the potential biofuel feedstock sites identified in the Greater Platte River Basin (GPRB). A 9-year (2000–2008) time series of net ecosystem production (NEP), a measure of net carbon absorption or emission by ecosystems, was used to assess the historical trends and budgets of carbon flux for grasslands in the GPRB. The spatially averaged annual NEP (ANEP) for grassland areas that are possibly suitable for biofuel expansion (productive grasslands) was 71–169 g C m−2 year−1 during 2000–2008, indicating a carbon sink (more carbon is absorbed than released) in these areas. The spatially averaged ANEP for areas not suitable for biofuel feedstock development (less productive or degraded grasslands) was −47 to 69 g C m−2 year−1 during 2000–2008, showing a weak carbon source or a weak carbon sink (carbon emitted is nearly equal to carbon absorbed). The 9-year pre-harvest cumulative ANEP was 1166 g C m−2 for the suitable areas (a strong carbon sink) and 200 g C m−2 for the non-suitable areas (a weak carbon sink). Results demonstrate and confirm that our method of dynamic modeling of ecosystem performance can successfully identify areas desirable and sustainable for future biofuel feedstock development. This study provides useful information for land managers and decision makers to make optimal land use decisions regarding biofuel feedstock development and sustainability.

  19. Tectonic evolution and paleokarstification of carbonate rocks in the Paleozoic Tarim Basin

    OpenAIRE

    Xu, Xuhui; Chen, Qianglu; Chu, Chenglin; Li, Guorong; Liu, Cunge; Shi, Zheng

    2016-01-01

    Thick carbonate rocks were developed in the depression of the Tarim craton during the Cambrian–Middle Ordovician periods. The compressional tectonic movement during the Middle Caledonian–Hercynian created the paleouplifts, which became the base for the paleokarst in the Ordovician carbonate rocks. Based on the large quantity of seismic, drilling, and geological outcrop data, this study analyzed the paleokarst development in relation to the multi-stage tectonic movements in the Paleozoic Era a...

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

    Science.gov (United States)

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

    2009-04-01

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

  1. Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2012-07-01

    Full Text Available We present the results of airborne measurements of carbon monoxide (CO and aerosol particle number concentration (CN made during the Balanço Atmosférico Regional de Carbono na Amazônia (BARCA program. The primary goal of BARCA is to address the question of basin-scale sources and sinks of CO2 and other atmospheric carbon species, a central issue of the Large-scale Biosphere-Atmosphere (LBA program. The experiment consisted of two aircraft campaigns during November–December 2008 (BARCA-A and May–June 2009 (BARCA-B, which covered the altitude range from the surface up to about 4500 m, and spanned most of the Amazon Basin.

    Based on meteorological analysis and measurements of the tracer, SF6, we found that airmasses over the Amazon Basin during the late dry season (BARCA-A, November 2008 originated predominantly from the Southern Hemisphere, while during the late wet season (BARCA-B, May 2009 low-level airmasses were dominated by northern-hemispheric inflow and mid-tropospheric airmasses were of mixed origin. In BARCA-A we found strong influence of biomass burning emissions on the composition of the atmosphere over much of the Amazon Basin, with CO enhancements up to 300 ppb and CN concentrations approaching 10 000 cm−3; the highest values were in the southern part of the Basin at altitudes of 1–3 km. The ΔCN/ΔCO ratios were diagnostic for biomass burning emissions, and were lower in aged than in fresh smoke. Fresh emissions indicated CO/CO2 and CN/CO emission ratios in good agreement with previous work, but our results also highlight the need to consider the residual smoldering combustion that takes place after the active flaming phase of deforestation fires.

    During the late wet season, in contrast, there was little evidence for a significant presence of biomass smoke. Low CN concentrations (300–500 cm−3 prevailed basinwide, and CO mixing ratios were enhanced

  2. Evidence from carbonate clumped isotope (Δ47) thermometry for the Late Cretaceous `Nevadaplano' in the northern Basin and Range Province

    Science.gov (United States)

    Snell, K. E.; Koch, P. L.; Eiler, J.

    2010-12-01

    From the middle Mesozoic to the present, the topography of the Basin and Range province (BRP) of the western Cordillera of North America has evolved in response to diverse tectonic forces, though the details are unclear for most of this period over most of this area. Much of the research on this region has focused on the Cenozoic record of paleoelevation during extension in the BRP. Some geodynamic models of this episode require high elevation prior to extension, but few studies have quantified the elevation of the pre-existing topography that developed during the Mesozoic in response to sustained convergence along the western coast of North America. Some workers have argued that the region was a high elevation plateau, the ‘Nevadaplano,’ analogous to the South American Altiplano. We tested this hypothesis using carbonate clumped isotope (Δ47) temperature estimates from Late Cretaceous lacustrine and paleosol carbonates. These samples come from the Sheep Pass Formation in east-central Nevada (presumed from geologic indications to be atop the plateau), and the North Horn Formation in central Utah on the eastern edge of the Sevier fold and thrust belt (presumably lower elevation). The textural characteristics, stable isotope compositions and carbonate clumped isotope temperature estimates from secondary carbonates in these units suggest that, despite moderate burial, primary carbonate samples have undergone little diagenetic alteration. Average temperatures from these two sites (23°C for the NV suite and 38°C for the UT suite) suggest that during the late Cretaceous (~66.5 Ma for the NV suite and 72 Ma for the UT suite), the NV site was ~15°C cooler than the UT site. This thermal gradient implies an elevation difference between the two sites of ~2.5 km, given certain assumptions: 1) there was little global or regional climate change during the ~5 million years between formation of these samples, 2) precipitation of both the lacustrine and paleosol carbonates

  3. Seasonal dynamics of carbon and nutrients from two contrasting tropical floodplain systems in the Zambezi River basin

    Science.gov (United States)

    Zuijdgeest, A. L.; Zurbrügg, R.; Blank, N.; Fulcri, R.; Senn, D. B.; Wehrli, B.

    2015-12-01

    Floodplains are important biogeochemical reactors during fluvial transport of carbon and nutrient species towards the oceans. In the tropics and subtropics, pronounced rainfall seasonality results in highly dynamic floodplain biogeochemistry. The massive construction of dams, however, has significantly altered the hydrography and chemical characteristics of many (sub)tropical rivers. In this study, we compare organic-matter and nutrient biogeochemistry of two large, contrasting floodplains in the Zambezi River basin in southern Africa: the Barotse Plains and the Kafue Flats. Both systems are of comparable size but differ in anthropogenic influence: while the Barotse Plains are still in large parts pristine, the Kafue Flats are bordered by two hydropower dams. The two systems exhibit different flooding dynamics, with a larger contribution of floodplain-derived water in the Kafue Flats and a stronger peak flow in the Barotse Plains. Distinct seasonal differences have been observed in carbon and nutrient concentrations, loads, and export and retention behavior in both systems. The simultaneous retention of particulate carbon and nitrogen and the net export of dissolved organic and inorganic carbon and nitrogen suggested that degradation of particulate organic matter was the dominant process influencing the river biogeochemistry during the wet season in the Barotse Plains and during the dry season in the Kafue Flats. Reverse trends during the dry season indicated that primary production was important in the Barotse Plains, whereas the Kafue Flats seemed to have both primary production and respiration occurring during the wet season, potentially occurring spatially separated in the main channel and on the floodplain. Carbon-to-nitrogen ratios of particulate organic matter showed that soil-derived material was dominant year-round in the Barotse Plains, whereas the Kafue Flats transported particulate organic matter that had been produced in the upstream reservoir during

  4. 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

  5. Production, storage, and output of particulate organic carbon: Waipaoa River basin, New Zealand

    Science.gov (United States)

    Gomez, Basil; Trustrum, N. A.; Hicks, D. M.; Rogers, K. M.; Page, M. J.; Tate, K. R.

    2003-06-01

    We compute the particulate organic carbon (POC) yield of the Waipaoa River, New Zealand, using sediment rating curves in conjunction with measurements of the carbon content of the suspended sediment. To ascertain the source of the carbon and the extent to which the POC flux is tied to different erosion processes, we determined the stable isotopic carbon composition (δ13C) and carbon to nitrogen (C/N) ratio of weathered bedrock, soil, and regolith. Most POC is derived from suspended sediment generated by gully erosion (incision into weathered bedrock), supplemented by landsliding during extreme events. The specific yield of POC from the headwaters (drainage area 1580 km2) is 55 g m-2 yr-1, which is very high by global standards and by comparison with other turbid steep-land rivers. The annual loss to floodplain storage is ˜4% (3.6 Kt) of the mean annual POC yield (86.7 Kt). Thus the Waipaoa River is a very effective conduit for transporting POC to the ocean.

  6. Geologic characterization and carbon storage resource estimates for the knox group, Illinois Basin, Illinois, Indiana and Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Harris, David; Ellett, Kevin; Rupp, John; Leetaru, Hannes

    2014-09-30

    Research documented in this report includes (1) refinement and standardization of regional stratigraphy across the 3-state study area in Illinois, Indiana, and Kentucky, (2) detailed core description and sedimentological interpretion of Knox cores from five wells in western Kentucky, and (3) a detailed calculation of carbon storage volumetrics for the Knox using three different methodologies. Seven regional cross sections document Knox formation distribution and thickness. Uniform stratigraphic nomenclature for all three states helps to resolve state-to-state differences that previously made it difficult to evaluate the Knox on a basin-wide scale. Correlations have also refined the interpretation of an important sandstone reservoir interval in southern Indiana and western Kentucky. This sandstone, a CO2 injection zone in the KGS 1 Blan well, is correlated with the New Richmond Sandstone of Illinois. This sandstone is over 350 ft (107 m) thick in parts of southern Indiana. It has excellent porosity and permeability at sufficient depths, and provides an additional sequestration target in the Knox. The New Richmond sandstone interval has higher predictability than vuggy and fractured carbonates, and will be easier to model and monitor CO2 movement after injection.

  7. Seasonal effects of irrigation on land-atmosphere latent heat, sensible heat and carbon fluxes in semi-arid basin

    Science.gov (United States)

    Xie, Zhenghui; Zeng, Yujin

    2017-04-01

    Irrigation, which constitutes 70% of the total amount of fresh water consumed by the human population, is significantly impacting the land-atmosphere fluxes. In this study, using the improved Community Land Model version 4.5 (CLM 4.5) with an active crop model, two high resolution ( 1 km) simulations investigating the effects of irrigation on Latent Heat (LH), Sensible Heat (SH) and Carbon Fluxes (or net ecosystem exchange, NEE) from land to atmosphere on the Heihe River Basin in northwestern China were conducted using a high-quality irrigation dataset compiled from 1981 to 2013. The model output and measurements from remote sensing demonstrated the capacity and viability of the developed models to reproduce ecological and hydrological processes. The results revealed the effects of irrigation on LH and SH are strongest during summer with a LH increase of 100 W/m2 and a SH decrease of 60 W/m2 over intensely irrigated areas. However, the reactions are much weaker during spring and autumn when there is much less irrigation. When the irrigation rate below 5 mm/day, the LH generally increases, whereas the SH decreases with growing irrigation rates. However, when the irrigation threshold is in excess of 5 mm/day, there is no accrued effect of irrigation on the LH and SH. Irrigation produces opposite effects to the NEE during spring and summer. During the spring, irrigation yields more discharged carbon from the land to the atmosphere, increasing the NEE value by 0.4-0.8 gC/m2/day, while the summer irrigation favors crop fixing of carbon from atmospheric CO2, decreasing the NEE value by 0.8 gC/m2/day. The repercussions of irrigation on land-atmosphere fluxes are not solely linked to the irrigation amount, and other parameters (especially the temperature) also control the effects of irrigation on LH, SH and NEE. The study indicates that how a land surface model with high spatial resolution can represent crop growing and its effects over basin scale.

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

    Science.gov (United States)

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

    2015-01-01

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

  9. Geologic framework for the national assessment of carbon dioxide storage resources: Columbia Basin of Oregon, Washington, and Idaho, and the Western Oregon-Washington basins: Chapter D in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Covault, Jacob A.; Blondes, Madalyn S.; Cahan, Steven M.; DeVera, Christina A.; Freeman, P.A.; Lohr, Celeste D.; Warwick, Peter D.; Corum, Margo D.

    2013-01-01

    The 2007 Energy Independence and Security Act (Public Law 110–140) directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used by the USGS for the national CO2 assessment follows that of previous USGS work. The methodology is non-economic and intended to be used at regional to subbasinal scales. This report identifies and contains geologic descriptions of three storage assessment units (SAUs) in Eocene and Oligocene sedimentary rocks within the Columbia, Puget, Willapa, Astoria, Nehalem, and Willamette Basins of Oregon, Washington, and Idaho, and focuses on the characteristics, specified in the methodology, that influence the potential CO2 storage resource in those SAUs. Specific descriptions of the SAU boundaries as well as their sealing and reservoir units are included. Properties for each SAU, such as depth to top, gross thickness, porosity, permeability, groundwater quality, and structural reservoir traps, are provided to illustrate geologic factors critical to the assessment. The designated sealing unit in the Columbia Basin is tentatively chosen to be the ubiquitous and thick Miocene Columbia River Basalt Group. As a result of uncertainties regarding the seal integrity of the Columbia River Basalt Group, the SAUs were not quantitatively assessed. Figures in this report show SAU boundaries and cell maps of well penetrations through sealing units into the top of the storage formations. The cell maps show the number of penetrating wells within one square mile and are derived from interpretations of incompletely attributed well data, a digital compilation that is known not to include all drilling. The USGS does not expect to know the location of all wells and cannot guarantee the amount of drilling through specific formations in any given cell shown on the cell maps.

  10. Carbon monoxide degassing from seismic fault zones in the Basin and Range province, west of Beijing, China

    Science.gov (United States)

    Sun, Yutao; Zhou, Xiaocheng; Zheng, Guodong; Li, Jing; Shi, Hongyu; Guo, Zhengfu; Du, Jianguo

    2017-11-01

    Degassing of carbon monoxide (CO), which plays a significant role in the contribution of deep carbon to the atmosphere, commonly occurs within active fault zones. CO degassing from soil to the atmosphere in the Basin and Range province, west of Beijing (BRPB), China, was investigated by in-situ field measurements in the active fault zones. The measured concentrations of CO in soil gas in the BRPB ranged from 0.29 × 10-6 to 1.1 × 10-6 with a mean value of 0.6 × 10-6, which is approximately twice as large as that in the atmosphere. Net fluxes of CO degassing ranged from -48.6 mg m-2 d-1 to 12.03 mg m-2 d-1. The diffusion of CO from soil to the atmosphere in the BRPB was estimated to be at least 7.6 × 103 ton/a, which is comparable to the corresponding result of about 1.2 × 104 ton/a for CO2. CO concentrations were spatially heterogeneous with clearly higher concentrations along the NE-SW trending in the BRPB. These elevated values of CO concentrations were also coincident with the region with low-velocity and high conductivity in deep mantle, and high Poisson's ratio in the crust, thereby suggesting that CO degassing from the soil might be linked to upwelling of the asthenospheric mantle. Other sources of CO in the soil gas are suggested to be dominated by chemical reactions between deep fluids and carbonate minerals (e.g., dolomite, limestone, and siderite) in country rocks. Biogenic processes may also contribute to the CO in soil gas. The spatial distribution patterns of CO concentrations are coincident with the stress field, suggesting that the concentrations of CO could be a potential indicator for crustal stress field and, hence is potential useful for earthquake monitoring in the BRPB.

  11. Seasonal effects of irrigation on land-atmosphere latent heat, sensible heat, and carbon fluxes in semiarid basin

    Science.gov (United States)

    Zeng, Yujin; Xie, Zhenghui; Liu, Shuang

    2017-02-01

    Irrigation, which constitutes ˜ 70 % of the total amount of freshwater consumed by the human population, is significantly impacting land-atmosphere fluxes. In this study, using the improved Community Land Model version 4.5 (CLM4.5) with an active crop model, two high-resolution (˜ 1 km) simulations investigating the effects of irrigation on latent heat (LH), sensible heat (SH), and carbon fluxes (or net ecosystem exchange, NEE) from land to atmosphere in the Heihe River basin in northwestern China were conducted using a high-quality irrigation dataset compiled from 1981 to 2013. The model output and measurements from remote sensing demonstrated the capacity of the developed models to reproduce ecological and hydrological processes. The results revealed that the effects of irrigation on LH and SH are strongest during summer, with a LH increase of ˜ 100 W m-2 and a SH decrease of ˜ 60 W m-2 over intensely irrigated areas. However, the reactions are much weaker during spring and autumn when there is much less irrigation. When the irrigation rate is below 5 mm day-1, the LH generally increases, whereas the SH decreases with growing irrigation rates. However, when the irrigation threshold is in excess of 5 mm day-1, there is no accrued effect of irrigation on the LH and SH. Irrigation produces opposite effects to the NEE during spring and summer. During the spring, irrigation yields more discharged carbon from the land to the atmosphere, increasing the NEE value by 0.4-0.8 gC m-2 day-1, while the summer irrigation favors crop fixing of carbon from atmospheric CO2, decreasing the NEE value by ˜ 0.8 gC m-2 day-1. The repercussions of irrigation on land-atmosphere fluxes are not solely linked to the irrigation amount, and other parameters (especially the temperature) also control the effects of irrigation on LH, SH, and NEE.

  12. Assessing the statistical robustness of inter- and intra-basinal carbon isotope chemostratigraphic correlation

    Science.gov (United States)

    Hay, C.; Creveling, J. R.; Huybers, P. J.

    2016-12-01

    Excursions in the stable carbon isotopic composition of carbonate rocks (δ13Ccarb) can facilitate correlation of Precambrian and Phanerozoic sedimentary successions at a higher temporal resolution than radiometric and biostratigraphic frameworks typically afford. Within the bounds of litho- and biostratigraphic constraints, stratigraphers often correlate isotopic patterns between distant stratigraphic sections through visual alignment of local maxima and minima of isotopic values. The reproducibility of this method can prove challenging and, thus, evaluating the statistical robustness of intrabasinal composite carbon isotope curves, and global correlations to these reference curves, remains difficult. To assess the reproducibility of stratigraphic alignment of δ13Ccarb data, and correlations between carbon isotope excursions, we employ a numerical dynamic time warping methodology that stretches and squeezes the time axis of a record to obtain an optimal correlation (in a least-squares sense) between time-uncertain series of data. In particular, we assess various alignments between series of Early Cambrian δ13Ccarb data with respect to plausible matches. We first show that an alignment of these records obtained visually, and published previously, is broadly reproducible using dynamic time warping. Alternative alignments with similar goodness of fits are also obtainable, and their stratigraphic plausibility are discussed. This approach should be generalizable to an algorithm for the purposes of developing a library of plausible alignments between multiple time-uncertain stratigraphic records.

  13. Coniacian-maastrichtian calcareous nannofossil biostratigraphy and carbon-isotope stratigraphy in the Zagros Basin (Iran)

    DEFF Research Database (Denmark)

    Razmjooei, Mohammad Javad; Thibault, Nicolas; Kani, Anoshiravan

    2014-01-01

    with magnetostratigraphy in the Santonian-early Campanian interval. The δ13C correlation, supported by calcareous nannofossil biostratigraphy, brings insights into: (1) the position of the Coniacian/Santonian, Santonian/Campanian and Campanian/Maastrichtian boundaries with respect to carbon-isotope stratigraphy...

  14. Authigenic carbonates in the sediments of Goa offshore basin, western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kocherla, M.

    Euhedral crystals (approx. 1 mm) of authigenic carbonates are identified in 5 m long sediment cores collected from the western continental margin of India in water depths between 2665 and 3070 m. Low-Mg calcite and aragonite are the dominant...

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

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; DeSousa, S.N.

    . The samples were not filtered in order to avoid any contamination. Total organic carbon (TOC) was analysed by Shimadzu TOC-5000 (precision, 5%) analyser using HTCO by platinum catalyst. The system blank and instrument blank were determined using UV oxidised...

  16. The Efficacy and Potential of Renewable Energy from Carbon Dioxide that is Sequestered in Sedimentary Basin Geothermal Resources

    Science.gov (United States)

    Bielicki, J. M.; Adams, B. M.; Choi, H.; Saar, M. O.; Taff, S. J.; Jamiyansuren, B.; Buscheck, T. A.; Ogland-Hand, J.

    2015-12-01

    Mitigating climate change requires increasing the amount of electricity that is generated from renewable energy technologies and while simultaneously reducing the amount of carbon dioxide (CO2) that is emitted to the atmosphere from present energy and industrial facilities. We investigated the efficacy of generating electricity using renewable geothermal heat that is extracted by CO2 that is sequestered in sedimentary basins. To determine the efficacy of CO2-Geothermal power production in the United States, we conducted a geospatial resource assessment of the combination of subsurface CO2 storage capacity and heat flow in sedimentary basins and developed an integrated systems model that combines reservoir modeling with power plant modeling and economic costs. The geospatial resource assessment estimates the potential resource base for CO2-Geothermal power plants, and the integrated systems model estimates the physical (e.g., net power) and economic (e.g., levelized cost of electricity, capital cost) performance of an individual CO2-Geothermal power plant for a range of reservoir characteristics (permeability, depth, geothermal temperature gradient). Using coupled inverted five-spot injection patterns that are common in CO2-enhanced oil recovery operations, we determined the well pattern size that best leveraged physical and economic economies of scale for the integrated system. Our results indicate that CO2-Geothermal plants can be cost-effectively deployed in a much larger region of the United States than typical approaches to geothermal electricity production. These cost-effective CO2-Geothermal electricity facilities can also be capacity-competitive with many existing baseload and renewable energy technologies over a range of reservoir parameters. For example, our results suggest that, given the right combination of reservoir parameters, LCOEs can be as low as $25/MWh and capacities can be as high as a few hundred MW.

  17. The response of methane and dissolved inorganic carbon biogeochemistry to sediment mass transport processes in the Argentine Basin

    Science.gov (United States)

    Formolo, M.; Riedinger, N.; Henkel, S.; Tomasini, J.; Strasser, M.; Vossmeyer, A.; Kasten, S.

    2010-12-01

    Here we present results from sediments and pore waters collected from the continental margin and slope off of Uruguay and Argentina. Sampling was focused in the western Argentine Basin during Expedition M78/3 (May - July, 2009) aboard the RV Meteor. The Argentine Basin has been well documented as a region susceptible to mass sediment transport processes and high sedimentation rates. These dynamic conditions impact the pore water and dissolved methane geochemistry. Sediment and pore water samples from M78/3 provide a unique opportunity to address the response of methane and dissolved inorganic carbon (DIC) concentrations and isotopic compositions, along with concomitant sulfate, to recent sediment transport processes. Adopting the definitions from Hensen et al. (2003) for pore water profiles from this region we have subdivided the sample locations into 4 categories; linear, concave-up, kink, and s-type. Comparisons among these categories allow us to address how methane and sulfate biogeochemistry responds to sediment movements and variable methane fluxes. Within the Argentine Basin the observed sulfate and methane geochemistry are transitory in nature following mass-flow deposition or variations in methane fluxes. Over time the pore water profiles are constantly returning to a more steady-state situation and information regarding these transient periods can be lost. However, information gained from these intermediate stages, such as concave-up, kink, and s-type, provides valuable insight into the true non-steady state and dynamic biogeochemical processes along the continental margin of southeast South America and other margin environments. These environments may provide a modern analogue for ancient methane release events from sediments subjected to mass-movement events. Incidents of sediment mass-movement may be a source of methane that is often too short-lived to observe in the geologic record but may have a strong impact on sediment geochemistry. Temporally

  18. 1:1,000,000-scale estimated outer extent of areas of groundwater discharge as evapotranspiration for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  19. Bacteria, carbon dioxide, and methane data from bottle casts in the Cariaco Basin on the continental shelf of Venezuela from the HERMANO GINES from 2001-04-30 to 2001-05-01 (NODC Accession 0000737)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bacteria, carbon dioxide, and methane data were collected from bottle casts from the HERMANO GINES in the Cariaco Basin on the continental shelf of Venezuela. Data...

  20. Bacteria, carbon dioxide, and methane data from bottle casts in the Cariaco Basin on the continental shelf of Venezuela from the HERMANO GINES from 2000-05-03 to 2000-10-31 (NODC Accession 0000732)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bacteria, carbon dioxide, and methane data were collected employing bottle casts from the Hermano Gines in the Cariaco Basin on the continental shelf of Venezuela....

  1. Mapping Congo Basin vegetation types from 300 m and 1 km multi-sensor time series for carbon stocks and forest areas estimation

    Directory of Open Access Journals (Sweden)

    A. Verhegghen

    2012-12-01

    Full Text Available This study aims to contribute to the understanding of the Congo Basin forests by delivering a detailed map of vegetation types with an improved spatial discrimination and coherence for the whole Congo Basin region. A total of 20 land cover classes were described with the standardized Land Cover Classification System (LCCS developed by the FAO. Based on a semi-automatic processing chain, the Congo Basin vegetation types map was produced by combining 19 months of observations from the Envisat MERIS full resolution products (300 m and 8 yr of daily SPOT VEGETATION (VGT reflectances (1 km. Four zones (north, south and two central were delineated and processed separately according to their seasonal and cloud cover specificities. The discrimination between different vegetation types (e.g. forest and savannas was significantly improved thanks to the MERIS sharp spatial resolution. A better discrimination was achieved in cloudy areas by taking advantage of the temporal consistency of the SPOT VGT observations. This resulted in a precise delineation of the spatial extent of the rural complex in the countries situated along the Atlantic coast. Based on this new map, more accurate estimates of the surface areas of forest types were produced for each country of the Congo Basin. Carbon stocks of the Basin were evaluated to a total of 49 360 million metric tons. The regional scale of the map was an opportunity to investigate what could be an appropriate tree cover threshold for a forest class definition in the Congo Basin countries. A 30% tree cover threshold was suggested. Furthermore, the phenology of the different vegetation types was illustrated systematically with EVI temporal profiles. This Congo Basin forest types map reached a satisfactory overall accuracy of 71.5% and even 78.9% when some classes are aggregated. The values of the Cohen's kappa coefficient, respectively 0.64 and 0.76 indicates a result significantly better than random.

  2. Evaluation of the potential of the Clare Basin, SW Ireland, for onshore carbon sequestration using electromagnetic geophysical methods

    Science.gov (United States)

    Llovet, Joan Campanya i.; Ogaya, Xenia; Jones, Alan G.; Rath, Volker; Ledo, Juanjo; McConnell, Brian

    2015-04-01

    Carbon capture, sequestration and long-term storage (CCS) is a critically important and intellectually and technologically challenging bridging technology for assisting humanity to migrate from its dependence on fossil fuels to green energy over the next half century. The IRECCSEM project (www.ireccsem.ie) is a Science Foundation Ireland Investigator Project to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic geophysical data with existing geophysical and geological data. The main goals of the project are to determine porosity and permeability values of the potential reservoir formation as well as to evaluate the integrity of the seal formation. During the summer of 2014, a magnetotelluric (MT) survey was carried out in the Carboniferous Clare Basin (SW Ireland). Data from a total of 140 sites were acquired, including audio-magnetotelluric (AMT), broadband magnetotelluric (BBMT) and long period magnetotelluric (LMT) data. These new data added to existing MT data acquired at 32 sites during a feasibility pilot survey conducted in 2010. The nominal space between the 2014 sites was 0.6 km between AMT sites, 1.2 km between BBMT sites and 8 km between LMT sites. The electrical resistivity distribution beneath the survey area was constrained using three different types of electromagnetic data: MT impedance tensor responses (Z), geomagnetic transfer functions (GTF) and inter-station horizontal magnetic transfer-functions (HMT). A newly-computed code based on the Generalized Archie's Law and available data from boreholes were used to relate the obtained geoelectrical model to rock properties (i.e. porosity and permeability). The results are compared to independent geological and geophysical data for superior interpretation.

  3. Methane and carbon dioxide production in soils flooded by the Belo Monte hydropower reservoir in the Amazon Basin, Brazil

    Science.gov (United States)

    Sawakuchi, H. O.; Bertassoli, D. J., Jr.; Silveira, A. M.; Bozi, B. S.; de Jesus, J. S.; Sawakuchi, A. O.; Ward, N. D.; Bastviken, D.; Krusche, A. V.; Richey, J. E.

    2016-12-01

    The Xingu River, one of the major tributary of the Amazon River, was recently impounded by the Belo Monte dam, a massive and controversial hydropower plant that will become the third biggest power station in generating capacity of the world. Given the limited data associated with greenhouse gas emissions from reservoirs in the Amazon basin, the impacts of hydroelectric expansion in this region to the global carbon budget remains unclear. Here, we used a bottom-up assessment to quantify a fraction of the possible emissions associated with the Belo Monte reservoir. Eighteen soil samples were collected before the impoundment from seven different locations and depths in areas that were going to be permanently flooded by the reservoir (forests and pasturelands). Soil samples were split in triplicates and incubated in anoxic conditions during two phases totaling 160 days of anoxic incubation in order to quantify the potential methane and carbon dioxide production through time. Our results showed that pasturelands soil presented higher potential production of both gases in relation to the soils from forested areas, reaching up to 0.072 mg CH4 g-¹d-1 and 0.078 mg CO2 g-¹d-1 during the first period of 65 days in the first phase of incubations. Significant differences in production were also noted through soil depth and time. In several areas, the first 15 cm of soil generated 99% of the methane volume that was being produced in the 60 cm sampled profile. The first 65 days of the second phase of incubations showed production that was 35% (CH4) and 44% (CO2) lower than the same period in the first stage. Extrapolations towards the total flooded area demonstrates that 27.3-43.3 ton CH4 d-1 may be generated from flooded soils in the Belo Monte reservoir during only the first several months of flooding, maintaining significant production rates during upcoming months as long as favorable conditions are maintained.

  4. Ground-water quality in the eastern part of the Silurian-Devonian and upper Carbonate aquifers in the eastern Iowa basins, Iowa and Minnesota, 1996

    Science.gov (United States)

    Savoca, Mark E.; Sadorf, Eric M.; Akers, Kymm K.B.

    1999-01-01

    Ground-water samples were collected from 33 domestic wells to assess the water quality of the eastern part of the Silurian-Devonian and Upper Carbonate aquifers in the Eastern Iowa Basins National Water-Quality Assessment Program study unit. Samples were collected during June and July 1996 and analyzed for major ions, nutrients, pesticides and pesticide metabolites, volatile organic compounds, tritium, radon222, and environmental isotopes.

  5. Evidences of methane-derived authigenic carbonates from the sediments of the Krishna–Godavari Basin, eastern continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kocherla, M.; Mazumdar, A.; Karisiddaiah, S.M.; Borole, D.V.; Rao, B.R.

    CURRENT SCIENCE, VOL. 91, NO. 3, 10 AUGUST 2006 *For correspondence. (e - mail: kocherla@nio.org) Evidences of methane - derived authigenic ca r bonates from the sediments of the Krishna ? Godavari Basin, eastern continental margin of India... and presence of framboidal pyrites are definite ev i- dences of anoxic diagenetic realm. Highly depleted carbon isotopic compositions of the handp icked ca r- bonate crystals are suggestive of anaerobic oxidation of methane (AOM). In this work a biogenic...

  6. Isotopically zoned carbonate cements in Early Paleozoic sandstones of the Illinois Basin: δ18O and δ13C records of burial and fluid flow

    Science.gov (United States)

    Denny, Adam C.; Kozdon, Reinhard; Kitajima, Kouki; Valley, John W.

    2017-11-01

    SEM/SIMS imaging and analysis of δ18O and δ13C in sandstones from a transect through the Illinois Basin (USA) show systematic μm-scale isotopic zonation of up to 10‰ in both carbonate and quartz cements of the middle-Ordovician St. Peter and Cambrian Mt. Simon formations. Quartz δ18O values are broadly consistent with the model of Hyodo et al. (2014), wherein burial and heating in the Illinois Basin is recorded in systematically zoned quartz overgrowths. Observations of zoned dolomite/ankerite cements indicate that they preserve a more extended record of temperature and fluid compositions than quartz, including early diagenesis before or during shallow burial, and late carbonates formed after quartz overgrowths. Many carbonate cements show innermost dolomite with δ18O values (21-25‰ VSMOW) that are too low to have formed by deposition at low temperatures from ancient seawater (δ18O > - 3‰) and most likely reflect mixing with meteoric water. A sharp increase in Fe content is commonly observed in zoned carbonate cements to be associated with a drop in δ18O and an abrupt shift in δ13C to higher or lower values. These changes are interpreted to record the passage of hot metal-rich brines through sandstone aquifers, that was associated with Mississippi-Valley Type (MVT) Pb-Zn deposits (ca. 270 Ma) of the Upper Mississippi Valley. Local variability and individual trends in δ13C are likely controlled by the sources of carbon and the degree to which carbon is sourced from adjacent carbonate units or thermal maturation of organic matter. Quartz overgrowths in sandstones provide an excellent record of conditions during burial, heating, and pressure-solution, whereas carbonate cements in sandstones preserve a more-extended record including initial pre-burial conditions and punctuated fluid flow events.

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

    Science.gov (United States)

    Dogramaci, Shawan; McLean, Laura; Skrzypek, Grzegorz

    2017-02-01

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

  8. Optical Properties Of Mineral Dust Particles Mixed With Black Carbon In Indo-Ganges Basin, Northern India

    Science.gov (United States)

    Mishra, S. K.; Tripathi, S. N.

    2008-12-01

    Among all the aerosol species estimation of radiative forcing of dust particles is most uncertain because of the difficulties in modeling accurately their optical properties due to our limited knowledge of their mineralogy and morphology (Sokolik and Toon, 1999). There is large variation in their shapes and mineralogical composition across the global deserts and the data available is limited. The problem becomes further complicated when these highly non spherical shaped particles interact with other absorbing particles e. g. Black Carbon emitted from pollution sources. The dust from Indian desert, while being transported through the Indo Gangetic basin during the Pre Monsoon season (March-May), mixes with BC particles present in large concentration in the region (Tripathi et al., 2005). The accurate estimation of optical properties of these particles, which could be different from pure dust or BC particles, is important because of their suspected impact on the development of monsoon (Lau et al, 2006). In this work, we have made an attempt to model the optical properties of these complicated aerosol systems. We have used dust mineralogical composition (absorbing and non absorbing) from the recent work of Mishra and Tripathi (2008), who modeled the optical properties of pure dust particles over Indian desert. Mixing state of the two species i.e. dust and BC is an important issue (Clarke et al., 2004) while modeling these systems. We consider both external and internal mixing scenarios while modeling in absence of any observational information. Earlier study on mixing state of aerosols (assuming them to be spherical in shape), in IGB, have indicated that dust coated with BC is the most probable scenario for internal mixing (Dey et al., 2008). In the present study, optical properties (scattering and absorption cross-sections, phase functions and asymmetry parameter) have been modeled using Discrete Dipole Approximation method (Draine and Flatau, 2004) for a variety of

  9. Basin-scale changes of total organic carbon profiles in the eastern South Atlantic

    Directory of Open Access Journals (Sweden)

    X. A. Alvarez-Salgado

    2001-03-01

    Full Text Available Total organic carbon (TOC samples were collected at 6 stations spaced ~800 km apart in the eastern South Atlantic, from the Equator to 45°S along 9°W. Analyses were performed by high temperature catalytic oxidation (HTCO in the base laboratory. Despite the complex advection and mixing patterns of North Atlantic and Antarctic waters with extremely different degrees of ventilation, TOC levels below 500 m are quasi-constant at 55±3 µmol C l-1, pointing to the refractory nature of deep-water TOC. On the other hand, a TOC excess from 25 to 38 g C m-2 is observed in the upper 100 m of the permanently stratified nutrient-depleted Equatorial, Subequatorial and Subtropical upper ocean, where vertical turbulent diffusion is largely prevented. Conversely, TOC levels in the nutrient-rich upper layer of the Subantarctic Front only exceeds 9 g C m-2 the deep-water baseline. As much as 70% of the TOC variability in the upper 500 m is due to simple mixing of reactive TOC formed in the surface layer and refractory TOC in deep ocean waters, with a minor contribution (13% to oxygen consumption in the prominent subsurface AOU maximum at 200-400 m depth.

  10. Arctic ocean shelf-basin interaction: An active continental shelf CO 2 pump and its impact on the degree of calcium carbonate solubility

    Science.gov (United States)

    Anderson, L. G.; Tanhua, T.; Björk, G.; Hjalmarsson, S.; Jones, E. P.; Jutterström, S.; Rudels, B.; Swift, J. H.; Wåhlstöm, I.

    2010-07-01

    The Arctic Ocean has wide shelf areas with extensive biological activity including a high primary productivity and an active microbial loop within the surface sediment. This in combination with brine production during sea ice formation result in the decay products exiting from the shelf into the deep basin typically at a depth of about 150 m and over a wide salinity range centered around S ˜33. We present data from the Beringia cruise in 2005 along a section in the Canada Basin from the continental margin north of Alaska towards the north and from the International Siberian Shelf Study in 2008 (ISSS-08) to illustrate the impact of these processes. The water rich in decay products, nutrients and dissolved inorganic carbon (DIC), exits the shelf not only from the Chukchi Sea, as has been shown earlier, but also from the East Siberian Sea. The excess of DIC found in the Canada Basin in a depth range of about 50-250 m amounts to 90±40 g C m -2. If this excess is integrated over the whole Canadian Basin the excess equals 320±140×10 12 g C. The high DIC concentration layer also has low pH and consequently a low degree of calcium carbonate saturation, with minimum aragonite values of 60% saturation and calcite values just below saturation. The mean age of the waters in the top 300 m was calculated using the transit time distribution method. By applying a future exponential increase of atmospheric CO 2 the invasion of anthropogenic carbon into these waters will result in an under-saturated surface water with respect to aragonite by the year 2050, even without any freshening caused by melting sea ice or increased river discharge.

  11. Impact of river-lake-groundwater interaction on boundless carbon cycle in continental basin

    Science.gov (United States)

    Nakayama, T.; Shankman, D.

    2012-12-01

    In the Changjiang River in south China, deforestation and land reclamation have induced serious soil erosion and increased floods. Although the Three Gorges Dam (TGD) will provide flood control, the aquatic environment might be changed by discharge control and pollutant loads caused by the deposition of large amounts of sediment in the upper dam (Yang et al., 2006). Some research implies that seepage of groundwater along the lower regions plays important role in maintaining stream flow and after TGD impounding by using natural radionuclides (Dai et al., 2010). It is effective to clarify complicated river-lake-groundwater interaction (Eltahir and Yeh, 1999; Dai et al., 2010), and to evaluate optimum amount of transferred water and environmental consequences in the basin. The authors have so far developed the process-based National Integrated Catchment-based Eco-hydrology (NICE) model (Nakayama, 2008a, 2008b, 2010, 2011a-b, 2012a-c; Nakayama and Fujita, 2010; Nakayama and Hashimoto, 2011; Nakayama and Watanabe, 2004, 2006, 2008a, 2008b; Nakayama et al., 2006, 2007, 2010, 2012), which includes complex interactions between the forest canopy, surface water, the unsaturated zone, aquifers, lakes, and rivers. The objective of this research is to estimate the impact of river-lake-groundwater interaction on hydrologic cycle and to predict the impact of TGD on the hydrologic change in the downstream Dongting and Poyang Lakes region by using a process-based model. Analysis of power spectra in river discharge also helps to understand its complex mechanism. This integrated system also throws some light on the improvement in boundless biogeochemical cycle along terrestrial-aquatic continuum (Cole et al., 2007). References; Cole, J.J. et al., Ecosystems, doi:10.1007/s10021-006-9013-8, 2007. Dai, Z. et al., Hydrogeol. J., 18, 359-369, 2010. Eltahir, E.A.B.& Yeh, P.J.-F., Water Resour. Res., 35(4), 1199-1217, 1999. Nakayama, T., Ecol. Model., doi:10.1016/j.ecolmodel.2008

  12. Types and characteristics of carbonate reservoirs and their implication on hydrocarbon exploration: A case study from the eastern Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Shiwei Huang

    2017-02-01

    Full Text Available Carbonate rocks are deposited in the Ordovician, Cambrian, and Sinian of eastern Tarim Basin with a cumulative maximum thickness exceeding 2000 m. They are the main carriers of oil and gas, and a great deal of natural gas has been found there in the past five years. Based on lithofacies and reservoir differences, natural gas exploration domains of eastern Tarim Basin can be classified into five types: Ordovician platform limestone; Ordovician platform dolomite; Cambrian platform margin mound shoal; Cambrian slope gravity flow deposits, and; Sinian dolomite. Carbonate reservoir characteristics of all the types were synthetically analyzed through observation on drilling core and thin sections, porosity and permeability measurement, and logging data of over 10 drilling wells. We find distribution of part of good fracture and cave reservoir in carbonate platform limestone of Ordovician. In the Ordovician, platform facies dolomite is better than limestone, and in the Cambrian, platform margin mound shoal dolomite has large stacking thickness. Good quality and significantly thick carbonate gravity deposit flow can be found in the Cambrian slope, and effective reservoir has also been found in Sinian dolomite. Commercial gas has been found in the limestone and dolomite of Ordovician in Shunnan and Gucheng areas. Exploration experiences from these two areas are instructive, enabling a deeper understanding of this scene.

  13. Comparison of Archaeal and Bacterial Diversity in Methane Seep Carbonate Nodules and Host Sediments, Eel River Basin and Hydrate Ridge, USA.

    Science.gov (United States)

    Mason, Olivia U; Case, David H; Naehr, Thomas H; Lee, Raymond W; Thomas, Randal B; Bailey, Jake V; Orphan, Victoria J

    2015-10-01

    Anaerobic oxidation of methane (AOM) impacts carbon cycling by acting as a methane sink and by sequestering inorganic carbon via AOM-induced carbonate precipitation. These precipitates commonly take the form of carbonate nodules that form within methane seep sediments. The timing and sequence of nodule formation within methane seep sediments are not well understood. Further, the microbial diversity associated with sediment-hosted nodules has not been well characterized and the degree to which nodules reflect the microbial assemblage in surrounding sediments is unknown. Here, we conducted a comparative study of microbial assemblages in methane-derived authigenic carbonate nodules and their host sediments using molecular, mineralogical, and geochemical methods. Analysis of 16S rRNA gene diversity from paired carbonate nodules and sediments revealed that both sample types contained methanotrophic archaea (ANME-1 and ANME-2) and syntrophic sulfate-reducing bacteria (Desulfobacteraceae and Desulfobulbaceae), as well as other microbial community members. The combination of geochemical and molecular data from Eel River Basin and Hydrate Ridge suggested that some nodules formed in situ and captured the local sediment-hosted microbial community, while other nodules may have been translocated or may represent a record of conditions prior to the contemporary environment. Taken together, this comparative analysis offers clues to the formation regimes and mechanisms of sediment-hosted carbonate nodules.

  14. Effect of Land Use Change on Soil Carbon Storage over the Last 40 Years in the Shi Yang River Basin, China

    Directory of Open Access Journals (Sweden)

    Shurong Yang

    2018-01-01

    Full Text Available Accounting for one quarter of China’s land area, the endorheic Shiyang River basin is a vast semi-arid to arid region in China’s northwest. Exploring the impact of changes in land use on this arid area’s carbon budget under global warming is a key component to global climate change research. Variation in the region’s soil carbon storage due to land use changes occurring between 1973 and 2012 was estimated. The results show that land use change has a significant impact on the soil carbon budget, with soil carbon storage having decreased by 3.89 Tg between 1973 and 2012. Grassland stored the greatest amount of soil carbon (114.34 Mg ha−1, whereas considerably lower carbon storage occurred in woodland (58.53 Mg ha−1, cropland (26.75 Mg ha−1 and unused land (13.47 Mg ha−1. Grasslands transformed into cropland, and woodlands degraded into grassland have substantially reduced soil carbon storage, suggesting that measures should be adopted to reverse this trend to improve soil productivity.

  15. Growth and demise of a Paleogene isolated carbonate platform of the Offshore Indus Basin, Pakistan: effects of regional and local controlling factors

    Science.gov (United States)

    Shahzad, Khurram; Betzler, Christian; Ahmed, Nadeem; Qayyum, Farrukh; Spezzaferri, Silvia; Qadir, Anwar

    2017-06-01

    Based on high-resolution seismic and well datasets, this paper examines the evolution and drowning history of a Paleocene-Eocene carbonate platform in the Offshore Indus Basin of Pakistan. This study uses the internal seismic architecture, well log data as well as the microfauna to reconstruct factors that governed the carbonate platform growth and demise. Carbonates dominated by larger benthic foraminifera assemblages permit constraining the ages of the major evolutionary steps and show that the depositional environment was tropical within oligotrophic conditions. With the aid of seismic stratigraphy, the carbonate platform edifice is resolved into seven seismic units which in turn are grouped into three packages that reflect its evolution from platform initiation, aggradation with escarpment formation and platform drowning. The carbonate factory initiated as mounds and patches on a Cretaceous-Paleocene volcanic complex. Further, the growth history of the platform includes distinct phases of intraplatform progradation, aggradation, backstepping and partial drownings. The youngest succession as late-stage buildup records a shift from benthic to pelagic deposition and marks the final drowning in the Early Eocene. The depositional trend of the platform, controlled by the continuing thermal subsidence associated with the cooling of volcanic margin lithosphere, was the major contributor of the accommodation space which supported the vertical accumulation of shallow water carbonate succession. Other factors such as eustatic changes and changes in the carbonate producers as a response to the Paleogene climatic perturbations played secondary roles in the development and drowning of these buildups.

  16. Impacts of climate variability and extreme events on the terrestrial carbon cycle of the Amazon basin

    Science.gov (United States)

    Harper, A. B.; Cox, P.; Wiltshire, A.; Friedlingstein, P.; Jones, C. D.; Mercado, L.; Groenendijk, M.; Sitch, S.

    2013-12-01

    Several climate models predict reduced dry season rainfall in the Amazon region as a consequence of climate change. Drier dry seasons could have profound negative consequences for the forest, since soil moisture levels are already near their lower limit during this time of the year. Two recent dry season droughts (during 2005 and 2010) could provide insight into the future of the region. These droughts were associated with sea surface temperature anomalies in the tropical North Atlantic Ocean. Additionally, El Niño-related temperature anomalies in the tropical Pacific Ocean can lead to drought in the northern Amazon. In this work, we use a land surface model with updated physiology and vegetation dynamics to investigate responses of the Amazon terrestrial carbon cycle to recent droughts. JULES (the Joint UK Land-Environment Simulator) is the land surface model in the Hadley Centre Earth System Model. Several recent model developments have improved its ability to replicate seasonal cycles of land fluxes in tropical forests, such as new plant functional types, plant trait-based physiological parameters, and a multi-layer canopy with two-stream radiation and sunfleck penetration. In addition, several non-standard updates to JULES can improve the model in this region: including a representation of deeper soils and efficient roots, and parameter optimization. The soil and rooting adjustments are based on previous work with the Simple Biosphere (SiB3) model, which has been tested extensively in the Amazon. SiB3 can include a climate-derived, spatially varying predictor of forest drought resistance, which enabled it to simulate forest response to persistent soil moisture deficits during two rainfall exclusion projects in the Amazon. We ran JULES from pre-industrial to present day, forced with observed climate, atmospheric CO2, and land use. A mixture of satellite- and ground-based observations was used to validate JULES seasonal cycles of surface fluxes, phenology

  17. Geothermal prospection in the Greater Geneva Basin (Switzerland and France). Impact of diagenesis on reservoir properties of the Upper Jurassic carbonate sediments

    Science.gov (United States)

    Makhloufi, Yasin; Rusillon, Elme; Brentini, Maud; Clerc, Nicolas; Meyer, Michel; Samankassou, Elias

    2017-04-01

    Diagenesis of carbonate rocks is known to affect the petrophysical properties (porosity, permeability) of the host rock. Assessing the diagenetic history of the rock is thus essential when evaluating any reservoir exploitation project. The Canton of Geneva (Switzerland) is currently exploring the opportunities for geothermal energy exploitation in the Great Geneva Basin (GGB) sub-surface. In this context, a structural analysis of the basin (Clerc et al., 2016) associated with reservoir appraisal (Brentini et al., 2017) and rock-typing of reservoir bodies of potential interest were conducted (Rusillon et al., 2017). Other geothermal exploitation projects elsewhere (e.g. Bavaria, south Germany, Paris Basin, France) showed that dolomitized carbonate rocks have good reservoir properties and are suitable for geothermal energy production. The objectives of this work are to (1) describe and characterize the dolomitized bodies in the GGB and especially their diagenetic history and (2) quantify the reservoir properties of those bodies (porosity, permeability). Currently, our study focuses on the Upper Jurassic sedimentary bodies of the GGB. Field and well data show that the dolomitization is not ubiquitous in the GGB. Results from the petrographical analyses of the Kimmeridgian cores (Humilly-2) and of field analogues (Jura, Saleve and Vuache mountains) display complex diagenetic histories, dependent of the study sites. The paragenesis exhibits several stages of interparticular calcite cementation as well as different stages of dolomitization and/or dedolomitization. Those processes seem to follow constrained path of fluid migrations through burial, faulting or exhumation during the basin's history. These complex diagenetic histories affected the petrophysical and microstructural properties via porogenesis (conservation of initial porosity, moldic porosity) and/or poronecrosis events. The best reservoir properties appear to be recorded in patch reef and peri

  18. Holocene late Pleistocene non-tropical carbonate sediments and tectonic history of the western rift basin margin of the southern Gulf of California

    Science.gov (United States)

    Halfar, Jochen; Godinez-Orta, Lucio; Goodfriend, Glenn A.; Mucciarone, David A.; Ingle, James C.; Holden, Peter

    2001-10-01

    Using high-resolution seismic reflection profiling and dating of (1) shallow marine vibracores and (2) sediments collected from uplifted marine terraces we reconstruct the tectonic history and sediment accumulation patterns of Holocene to late Pleistocene warm-temperate to subtropical carbonates in the southern Gulf of California, Mexico. The study was conducted in the vicinity of La Paz where carbonates form along the fault bounded narrow western shelf of the tectonically active Gulf of California rift basin. The non-tropical nature of the setting is responsible for (1) poor cementation of the bioclastic carbonates, and (2) a composition which is dominated by rhodoliths (coralline red algae), corals and mollusks. Unrimmed carbonate flats forming in small pocket bays and a rhodolith bioherm, which has a surface area of more than 20 km2 and is up to 16 m thick, constitute the major carbonate factories. Holocene carbonate accumulation rates were deduced from seismic and core data and are highest on the rhodolith bioherm (260 cm/ka) and in subtidal zones of pocket bays (210 cm/ka), and lowest on the inner and middle shelf (100 cm/ka). Taken together, rates of carbonate accumulation are intermediate in magnitude between higher rates recorded in fully tropical carbonate settings and lower rates typical of cool-water carbonates. Seismic reflection profiles demonstrate that Isla Espiritu Santo in the center of the study area is a west dipping fault block, which is tectonically influenced by two distinct faults, the La Paz and Espiritu Santo faults. The latter fault accommodates at least 700 m of east-side down normal offset, and forms a steep eastern escarpment leading into the La Paz slope basin. Some of the sediments produced in the shallow carbonate factories of the narrow La Paz shelf are transported across this escarpment and are redeposited in the slope basin at a water depth of 750 m. Uranium-series dates of marine terraces exposed on Isla Espiritu Santo indicate

  19. Spatial variability of soil carbon stock in the Urucu river basin, Central Amazon-Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ceddia, Marcos Bacis, E-mail: marcosceddia@gmail.com [Department of Soil, Institute of Agronomy, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ 23890-000 (Brazil); Villela, André Luis Oliveira [Colégio Técnico da UFRRJ, RJ, Seropédica 23890-000 (Brazil); Pinheiro, Érika Flávia Machado [Department of Soil, Institute of Agronomy, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ 23890-000 (Brazil); Wendroth, Ole [Department of Plant & Soil Sciences, University of Kentucky, College of Agriculture, Lexington, KY (United States)

    2015-09-01

    The Amazon Forest plays a major role in C sequestration and release. However, few regional estimates of soil organic carbon (SOC) stock in this ecoregion exist. One of the barriers to improve SOC estimates is the lack of recent soil data at high spatial resolution, which hampers the application of new methods for mapping SOC stock. The aims of this work were: (i) to quantify SOC stock under undisturbed vegetation for the 0–30 and the 0–100 cm under Amazon Forest; (ii) to correlate the SOC stock with soil mapping units and relief attributes and (iii) to evaluate three geostatistical techniques to generate maps of SOC stock (ordinary, isotopic and heterotopic cokriging). The study site is located in the Central region of Amazon State, Brazil. The soil survey covered the study site that has an area of 80 km{sup 2} and resulted in a 1:10,000 soil map. It consisted of 315 field observations (96 complete soil profiles and 219 boreholes). SOC stock was calculated by summing C stocks by horizon, determined as a product of BD, SOC and the horizon thickness. For each one of the 315 soil observations, relief attributes were derived from a topographic map to understand SOC dynamics. The SOC stocks across 30 and 100 cm soil depth were 3.28 and 7.32 kg C m{sup −2}, respectively, which is, 34 and 16%, lower than other studies. The SOC stock is higher in soils developed in relief forms exhibiting well-drained soils, which are covered by Upland Dense Tropical Rainforest. Only SOC stock in the upper 100 cm exhibited spatial dependence allowing the generation of spatial variability maps based on spatial (co)-regionalization. The CTI was inversely correlated with SOC stock and was the only auxiliary variable feasible to be used in cokriging interpolation. The heterotopic cokriging presented the best performance for mapping SOC stock. - Highlights: • The SOC stocks across 30 and 100 cm depth were 3.28 and 7.32 kg C m{sup −2}, respectively. • SOC stocks were 34 and 16

  20. Assessments of carbon and water cycling in multiple agricultural ecosystems in the Inland Pacific Northwest using eddy covariance flux measurements and integrated basin-crop model simulation

    Science.gov (United States)

    Chi, J.; Maureira, F.; Waldo, S.; O'Keeffe, P.; Pressley, S. N.; Stockle, C. O.; Lamb, B. K.

    2014-12-01

    Local meteorology, crop management practices and site characteristics have important impacts on carbon and water cycling in agricultural ecosystems. This study focuses on carbon and water fluxes measured using eddy covariance (EC) methods and crop simulation models in the Inland Pacific Northwest (IPNW), in association with the Regional Approaches to Climate Change (REACCH) program. The agricultural ecosystem is currently challenged by higher pressure on water resources as a consequence of population growth and increasing exposure to impacts associated with different types of crop managements. In addition, future climate projections for this region show a likely increase in temperature and significant reductions in precipitation that will affect carbon and water dynamics. This new scenario requires an understanding of crop management by assessing efficient ways to face the impacts of climate change at the micrometeorological level, especially in regards to carbon and water flow. We focus on three different crop management sites. One site (LIND) under crop-fallow is situated in a low-rainfall area. The other two sites, one no-till site (CAF-NT) and one conventional tillage site (CAF-CT), are located in an area of high-rainfall with continuous cropping. In this study, we used CropSyst micro-basin model to simulate the responses in carbon and water budgets at each site. Based on the EC processed results for net ecosystem exchange (NEE) of CO2, the CAF-NT site was a carbon sink during 2013 when spring garbanzo was planted; while the paired CAF-CT site, under similar crop rotation and meteorological conditions, was a carbon source during the same period. The LIND site was also a carbon sink where winter wheat was growing during 2013. Model results for CAF-NT showed good agreement with the EC carbon and water flux measurements during 2013. Through comparisons between measurements and modeling results, both short and long term processes that influence carbon and water

  1. Quantification of CO2 generation in sedimentary basins through carbonate/clays reactions with uncertain thermodynamic parameters

    Science.gov (United States)

    Ceriotti, G.; Porta, G. M.; Geloni, C.; Dalla Rosa, M.; Guadagnini, A.

    2017-09-01

    We develop a methodological framework and mathematical formulation which yields estimates of the uncertainty associated with the amounts of CO2 generated by Carbonate-Clays Reactions (CCR) in large-scale subsurface systems to assist characterization of the main features of this geochemical process. Our approach couples a one-dimensional compaction model, providing the dynamics of the evolution of porosity, temperature and pressure along the vertical direction, with a chemical model able to quantify the partial pressure of CO2 resulting from minerals and pore water interaction. The modeling framework we propose allows (i) estimating the depth at which the source of gases is located and (ii) quantifying the amount of CO2 generated, based on the mineralogy of the sediments involved in the basin formation process. A distinctive objective of the study is the quantification of the way the uncertainty affecting chemical equilibrium constants propagates to model outputs, i.e., the flux of CO2. These parameters are considered as key sources of uncertainty in our modeling approach because temperature and pressure distributions associated with deep burial depths typically fall outside the range of validity of commonly employed geochemical databases and typically used geochemical software. We also analyze the impact of the relative abundancy of primary phases in the sediments on the activation of CCR processes. As a test bed, we consider a computational study where pressure and temperature conditions are representative of those observed in real sedimentary formation. Our results are conducive to the probabilistic assessment of (i) the characteristic pressure and temperature at which CCR leads to generation of CO2 in sedimentary systems, (ii) the order of magnitude of the CO2 generation rate that can be associated with CCR processes.

  2. Oil and gas accumulations in the Ordovician carbonates in the Tazhong Uplift of Tarim Basin, west China

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiu-Xiang; Jin, Zhi-Jun [Key Laboratory for Petroleum Accumulation in Petroleum University, Ministry of Education, Changping, Beijing 102249 (China); Liu, Luo-Fu; Xu, Shi-Lin [Basin and Reservoir Research Center, University of Petroleum, Changping, Beijing 102249 (China); Zhou, Xin-Yuan; Pi, Xue-Jun; Yang, Hai-Jun [Tarim Oil Field Company, Kurle, Xinjiang 841000 (China)

    2004-01-01

    Oil and gas fields of the Paleozoic cratonic basin in Tarim are mainly distributed in the Tabei and the Tazhong Uplifts. In the Tazhong Uplift, there are three sets of oil and gas stratum systems, of which the Ordovician traps are the largest in size and close to oil source beds with the most favorable conditions to form large-scale oil and gas fields. The Ordovician sediments in the Tazhong Uplift have experienced a stable platform and tableland margin development period. The Ordovician is divided into mudstone interval, interbedded mudstone and limestone interval, limestone interval, limestone and dolomite transitional interval and dolomite interval. Of these intervals, both interbedded mudstone and limestone interval and limestone interval contain source rocks, while limestone interval and dolomite interval are reservoir beds. Fault activities and denudation have an obvious impact on carbonate rock reservoirs. The major Ordovician trap types of the Tazhong Uplift include compressional fault block, fault anticline and buried hill, and regionally. The Tazhong Uplift can be generally divided into central fault horst trap belt, northern slope trap belt and southern slope trap belt. In view of the in-situ oil source in the Tazhong, oil and gas migration in the Tazhong Uplift is characterized by a short distance migration through sand bodies and unconformity surfaces laterally and along faults vertically. Based on this study, it is concluded that the favorable oil and gas accumulation zone should be the northern slope and the northwestern pitchout end of the uplift because these areas are located in the hydrocarbon migration pathway with weak tectonic activities and favorable preservation conditions.

  3. Heterogeneous Shallow-Shelf Carbonate Buildups in the Paradox Basin, Utah and Colorado: Targets for Increased Oil Production and Reserves Using Horizontal Drilling Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chidsey, Thomas C. Jr.; Eby, David E.; Wray, Laura L.

    2001-04-19

    The primary objective of this project was to enhance domestic petroleum production by demonstration and transfer of horizontal drilling technology in the Paradox basin, Utah, Colorado, Arizona, and New Mexico. If this project can demonstrate technical and economic feasibility, then the technique can be applied to approximately 100 additional small fields in the Paradox basin alone, and result in increased recovery of 25 to 50 million barrels (40-80 million m3) of oil. This project was designed to characterize several shallow-shelf carbonate reservoirs in the Pennsylvania (Desmoinesian) Paradox Formation, choose the best candidate(s) for a pilot demonstration project to drill horizontally from existing vertical wells, monitor well performances, and report associated validation activities.

  4. Annual water, sediment, nutrient, and organic carbon fluxes in river basins: A global meta-analysis as a function of scale

    Science.gov (United States)

    Mutema, M.; Chaplot, V.; Jewitt, G.; Chivenge, P.; Blöschl, G.

    2015-11-01

    Process controls on water, sediment, nutrient, and organic carbon exports from the landscape through runoff are not fully understood. This paper provides analyses from 446 sites worldwide to evaluate the impact of environmental factors (MAP and MAT: mean annual precipitation and temperature; CLAY and BD: soil clay content and bulk density; S: slope gradient; LU: land use) on annual exports (RC: runoff coefficients; SL: sediment loads; TOCL: organic carbon losses; TNL: nitrogen losses; TPL: phosphorus losses) from different spatial scales. RC was found to increase, on average, from 18% at local scale (in headwaters), 25% at microcatchment and subcatchment scale (midreaches) to 41% at catchment scale (lower reaches of river basins) in response to multiple factors. SL increased from microplots (468 g m-2 yr-1) to plots (901 g m-2 yr-1), accompanied by decreasing TOCL and TNL. Climate was a major control masking the effects of other factors. For example, RC, SL, TOCL, TNL, and TPL tended to increase with MAP at all spatial scales. These variables, however, decreased with MAT. The impact of CLAY, BD, LU, and S on erosion variables was largely confined to the hillslope scale, where RC, SL, and TOCL decreased with CLAY, while TNL and TPL increased. The results contribute to better understanding of water, nutrient, and carbon cycles in terrestrial ecosystems and should inform river basin modeling and ecosystem management. The important role of spatial climate variability points to a need for comparative research in specific environments at nested spatiotemporal scales.

  5. Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park.

    Science.gov (United States)

    Moran, James J; Whitmore, Laura M; Isern, Nancy G; Romine, Margaret F; Riha, Krystin M; Inskeep, William P; Kreuzer, Helen W

    2016-05-01

    The Norris Geyser Basin in Yellowstone National Park contains a large number of hydrothermal systems, which host microbial populations supported by primary productivity associated with a suite of chemolithotrophic metabolisms. We demonstrate that Metallosphaera yellowstonensis MK1, a facultative autotrophic archaeon isolated from a hyperthermal acidic hydrous ferric oxide (HFO) spring in Norris Geyser Basin, excretes formaldehyde during autotrophic growth. To determine the fate of formaldehyde in this low organic carbon environment, we incubated native microbial mat (containing M. yellowstonensis) from a HFO spring with (13)C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilated by members of the community. Autotrophy, formaldehyde oxidation, and formaldehyde assimilation displayed different sensitivities to chemical inhibitors, suggesting that distinct sub-populations in the mat selectively perform these functions. Our results demonstrate that electrons originally resulting from iron oxidation can energetically fuel autotrophic carbon fixation and associated formaldehyde excretion, and that formaldehyde is both oxidized and assimilated by different organisms within the native microbial community. Thus, formaldehyde can effectively act as a carbon and electron shuttle connecting the autotrophic, iron oxidizing members with associated heterotrophic members in the HFO community.

  6. Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park

    Energy Technology Data Exchange (ETDEWEB)

    Moran, James J.; Whitmore, Laura M.; Isern, Nancy G.; Romine, Margaret F.; Riha, Krystin M.; Inskeep, William P.; Kreuzer, Helen W.

    2016-03-19

    The Norris Geyser Basin in Yellowstone National Park contains a large number of hydrothermal systems, which host microbial populations supported by primary productivity associated with a suite of chemolithotrophic metabolisms. We demonstrate that Metallosphaera yellowstonesis MK1, a facultative autotrophic archaeon isolated from a hyperthermal acidic hydrous ferric oxide (HFO) spring in Norris Geyser Basin, excretes formaldehyde during autotrophic growth. To determine the fate of formaldehyde in this low organic carbon environment, we incubated native microbial mat (containing M. yellowstonensis) from a HFO spring with 13C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilated by members of the community. Autotrophy, formaldehyde oxidation, and formaldehyde assimilation displayed different sensitivities to chemical inhibitors, suggesting that distinct sub-populations in the mat selectively perform these functions. Our results demonstrate that electrons originally resulting from iron oxidation can energetically fuel autotrophic carbon fixation and associated formaldehyde excretion, and that formaldehyde is both oxidized and assimilated by different organisms within the native microbial community. Thus, formaldehyde can effectively act as a carbon and electron shuttle connecting the autotrophic, iron oxidizing members with associated heterotrophic members in the HFO community.

  7. Evolution of the Toarcian (Early Jurassic) carbon-cycle and global climatic controls on local sedimentary processes (Cardigan Bay Basin, UK)

    Science.gov (United States)

    Xu, Weimu; Ruhl, Micha; Jenkyns, Hugh C.; Leng, Melanie J.; Huggett, Jennifer M.; Minisini, Daniel; Ullmann, Clemens V.; Riding, James B.; Weijers, Johan W. H.; Storm, Marisa S.; Percival, Lawrence M. E.; Tosca, Nicholas J.; Idiz, Erdem F.; Tegelaar, Erik W.; Hesselbo, Stephen P.

    2018-02-01

    The late Early Jurassic Toarcian Stage represents the warmest interval of the Jurassic Period, with an abrupt rise in global temperatures of up to ∼7 °C in mid-latitudes at the onset of the early Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma). The T-OAE, which has been extensively studied in marine and continental successions from both hemispheres, was marked by the widespread expansion of anoxic and euxinic waters, geographically extensive deposition of organic-rich black shales, and climatic and environmental perturbations. Climatic and environmental processes following the T-OAE are, however, poorly known, largely due to a lack of study of stratigraphically well-constrained and complete sedimentary archives. Here, we present integrated geochemical and physical proxy data (high-resolution carbon-isotope data (δ13 C), bulk and molecular organic geochemistry, inorganic petrology, mineral characterisation, and major- and trace-element concentrations) from the biostratigraphically complete and expanded entire Toarcian succession in the Llanbedr (Mochras Farm) Borehole, Cardigan Bay Basin, Wales, UK. With these data, we (1) construct the first high-resolution biostratigraphically calibrated chemostratigraphic reference record for nearly the complete Toarcian Stage, (2) establish palaeoceanographic and depositional conditions in the Cardigan Bay Basin, (3) show that the T-OAE in the hemipelagic Cardigan Bay Basin was marked by the occurrence of gravity-flow deposits that were likely linked to globally enhanced sediment fluxes to continental margins and deeper marine (shelf) basins, and (4) explore how early Toarcian (tenuicostatum and serpentinum zones) siderite formation in the Cardigan Bay Basin may have been linked to low global oceanic sulphate concentrations and elevated supply of iron (Fe) from the hinterland, in response to climatically induced changes in hydrological cycling, global weathering rates and large-scale sulphide and evaporite deposition.

  8. Multiphase Calcite Cementation and Fluids Evolution of a Deeply Buried Carbonate Reservoir in the Upper Ordovician Lianglitag Formation, Tahe Oilfield, Tarim Basin, NW China

    OpenAIRE

    Jiaqing Liu; Zhong Li; Lijuan Cheng; Jiawei Li

    2017-01-01

    Oil and gas have been found in the Upper Ordovician Lianglitag Formation carbonates in the Tahe Oilfield, Tarim Basin, NW China. This study documents the origin of diagenetic fluids by using a combination of petrology, SIMS, fluid inclusion, and radiogenic isotope analysis. Six stages of calcite cements were revealed. C1-C2 formed in marine to early burial environments. C3 has relatively low δ18OVPDB values (−8.45‰ to −6.50‰) and likely has a meteoric origin. Meteoric water probably fluxed in...

  9. Soil carbon and nitrogen in a Great Basin pinyon-juniper woodland: Influence of vegetation, burning, and time

    Science.gov (United States)

    B. M. Rau; D. W. Johnson; R. R. Blank; J. C. Chambers

    2009-01-01

    Much of the Great Basin, U.S. is currently dominated by sagebrush (Artemisia tridentate ssp. (Rydb.) Boivin) ecosystems. At intermediate elevations, sagebrush ecosystems are increasingly influenced by pinyon (Pinus monophylla Torr. & Frem.) and juniper (Juniperus osteosperma Torr.) expansion. Some...

  10. Characteristics of depositional sequences, systems tracts and bounding surfaces in Early Ordovician greenhouse passive margin carbonates to Late Ordovician glacio-eustatic influenced foreland basin facies

    Energy Technology Data Exchange (ETDEWEB)

    Pope, M.C.; Read, J.F. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Geology)

    1994-03-01

    Passive margin, cyclic carbonates of the Early Ordovician Knox Group, Appalachians are dominated by meter scale dolomitized carbonate cycles. These are stacked into 1 to 5 m.y. depositional sequences that appear to be relatively conformable. The sequences are defined by stacking patterns on Fischer plots that graph long term changes in accommodation with thick less dolomitized cycles in the TST, and thin, highly dolomitized cycles in the HST, becoming quartzose in the late HST and LST. Sequence and systems tract boundaries are subtle and typically marked by zones of cycles rather than single discrete surfaces. In contrast, sequences in the later Ordovician foreland basin fill locally show: (1) sequence bounding unconformities on the Knox, the Camp Nelson and on top of the Ordovician, (2) well defined low stand deposits as in the subaerial breccias and detrital dolomite muds veneering the Knox unconformity; redbeds and associated quartz sands and conglomerates with intercalated peritidal carbonate layers and their distal equivalent peritidal laminites; (3) TST's in the lower part of the Middle Ordovician limestones include regionally traceable cyclic peritidal carbonates or in the lower Lexington Limestone, transgressive high energy grainstones; (4) HST's consist of poorly cyclic deeper water up into shallow water grainstone bank and northward prograding peritidal carbonate facies; The ongoing study of detailed logs of outcrop and core should help refine the understanding of the fine scale makeup of sequences developed in these contrasting tectonic and global climatic settings.

  11. Mixed carbonate-siliciclastic sedimentation in forebulge grabens: An example from the Ediacaran Bambuí Group, São Francisco Basin, Brazil

    Science.gov (United States)

    Reis, Humberto L. S.; Suss, João F.

    2016-06-01

    Mixed carbonate-siliciclastic successions have been described in multiple Phanerozoic sedimentary settings recording the dynamic interplay of tectonics, eustasy, climate, in situ carbonate production, and variations in siliciclastic sediment supply. The Ediacaran Bambuí 1st-order sequence (i.e., Bambuí Group) covers most of the intracratonic São Francisco basin (southeast Brazil) and encompasses thick packages of carbonate and fine- to coarse-grained siliciclastic strata. Recording a marine foreland basin stage that developed in the São Francisco plate during the Neoproterozoic-early Paleozoic West Gondwana assembly, the Ediacaran deposits unconformably overlie Archean-Paleoproterozoic metamorphic assemblages of the Sete Lagoas basement high and fill a series of kilometer-long grabens in the southern São Francisco basin. Seismic data reveal that these troughs developed through the extensional reactivation of ancient basement structures along with the tectonically driven forebulge uplift of the Sete Lagoas high, in the early evolutionary stages of the Bambuí basin cycle. Based on the detailed description of continuous drill cores of a well recently drilled during hydrocarbon exploration campaigns, we recognized two transgressive-regressive 2nd-order sequences preserved within one of the focused grabens: (i) Sequence 1 includes the glaciogenic deposits of the basal Carrancas Formation that grade upward into the carbonate ramp successions of the Sete Lagoas Formation; (ii) Sequence 2 contains the siliciclastic-dominated and deep water to deltaic strata of the Serra de Santa Helena Formation and passes upward into peritidal carbonates of the Lagoa do Jacaré Formation. These sedimentary successions encompass suites of retrogradational, aggradational, and progradational lower-rank cycles and are bounded by erosional surfaces. Regional seismic interpretation, well data, and the available literature indicate that most of these deposits and their correlatives are

  12. Integration of seismic interpretation and well logging analysis of Abu Roash D Member, Gindi Basin, Egypt: Implication for detecting and evaluating fractured carbonate reservoirs

    Science.gov (United States)

    Sarhan, Mohammad Abdelfattah; Basal, A. M. K.; Ibrahim, Ibrahim Mohamed

    2017-11-01

    Based on seismic interpretation, the time structure map on top of the Abu Roash D Member in the area of study within the Gindi Basin displays an NE-SW anticline plunging toward the NE intersected by two NE-SW reverse faults. This faulted anticline has been interpreted to have formed by the Late Cretaceous tectonic inversion resulting from the NW movement of the African Plate relative to Laurasia. This anticline creates a distinctive closure which may represent a possible structural hydrocarbon trap in the fractured limestone of the Abu Roash D Member in this area. Through well-logging analysis, the variable cementation exponent ;m; has been calculated using the Pickett Plot for the available wells in order to examine the presence of fractures within the entire carbonate Abu Roash D Member. The calculated ;m; for Abu Roash D in the two studied wells are 1.56 and 1.34 for SWQ-21 and SWQ-25; respectively which is indicative of the fractured limestone nature. The application of the correct ;m; (1.56) instead of 2 (traditional for the intergranular carbonate) for SWQ-21 well has revealed that, the water saturation for the uppermost part of Abu Roash D Member is lower than 50% (normal cut off for carbonate) possessing high porosity and reflecting good reservoir quality. The cross-plot between Archie water saturation (Sw) and neutron porosity (ΦN) for the uppermost part of this Member follows hyperbola with low BVW (Φ*Sw) value (0.06) which means that the reservoir is at irreducible state. The visual inspection for the log curve shapes in addition to the application of the presented technique in SWQ-25 well shows that the entire carbonate of Abu Roash D Member is water producing (Sw>50%). These results indicate that the upperpost part of the Abu Roash D Member in well SWQ-21 is fractured limestone and highly promising for hydrocarbon exploration within the Gindi Basin.

  13. Isotopic composition of carbon in atmospheric air; use of a diffusion model at the water/atmosphere interface in Velenje Basin

    Directory of Open Access Journals (Sweden)

    Tjaša Kanduč

    2015-07-01

    Full Text Available CO2 concentrations (partial pressure of CO2, pCO2, and isotope compositions of carbon dioxide in air (δ13CCO2, temperature (T and relative humidity (H have been measured in the atmosphere in the Velenje Basin. Samples were collected monthly in the calendar year 2011 from 9 locations in the area where the largest thermal power plant in Slovenia with the greatest emission of CO2 to the atmosphere (around 4M t/year is located. Values of pCO2 ranged from 239 to 460 ppm with an average value of 294 ppm, which is below the average atmospheric CO2 pressure (360 ppm. δ13CCO2 ranged from -18.0 to -6.4 ‰, with an average value of -11.7 ‰. These values are similar to those measured in Wroclaw, Poland. We performed the comparison of δ13CCO2 values in atmospheric air with Wroclaw since researchers used similar approach to trace δ13CCO2 around anthropogenic sources. The isotopic composition of dissolved inorganic carbon (δ13CDIC in rivers and lakes from the Velenje basin changes seasonally from -13.5 to -7.1‰. The values of δ13CDIC indicate the occurrence of biogeochemical processes in the surface waters, with dissolution of carbonates and degradation of organic matter being the most important. A concentration and diffusion model was used to calculate the time of equilibration between dissolved inorganic carbon in natural sources (rivers and atmospheric CO2.

  14. Mud volcanism and authigenic carbonates related to methane-rich fluids migration in the Tortonian-Messinian marls of the Huercal Overa basin (S.E. Spain)

    Science.gov (United States)

    Pierre, Catherine; Blanc-Valleron, Marie-Madeleine; Rouchy, Jean-Marie

    2017-04-01

    Methane-rich fluids that are generated at depth in organic-rich deposits migrate within the sediments to the seafloor where they are expelled to form mud volcanoes or pockmarks. These migrating fluids are generally involved in diagenetic processes as authigenic carbonate formation that is mediated by microbial activity and they may participate to gas hydrate formation. These features are well-known in the present-day continental margins but their fossil records are relatively scarce. In the Huercal Overa basin (South East Spain), there are chaotic to roughly layered structures intruding the Tortonian-Messinian marls that are interpreted as due to mud volcanism. Moreover, the surrounding marls contain abundant authigenic dolomite nodules. The oxygen and carbon isotopic compositions of these dolomites exhibit wide ranges (-1.4 fluids that might be relatively warm as shown by the low δ18O values and where anaerobic oxidation of methane (low δ13C values) and methanogenesis (high δ13C values) were active. These two features, methane derived authigenic dolomites and mud volcanism, are testifying of the intense methane-rich fluid migration in the marly deposits of the western Mediterranean basins during the late Neogene, which was the time of major paleoenvironmental changes in the Mediterranean sea climaxing during the Messinian salinity crisis.

  15. Origin of red pelagic carbonates as an interplay of global climate and local basin factors: Insight from the Lower Devonian of the Prague Basin, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Bábek, O.; Faměra, Martin; Hladil, Jindřich; Kapusta, J.; Weinerová, Hedvika; Šimíček, D.; Slavík, Ladislav; Ďurišová, Jana

    2018-01-01

    Roč. 364, FEB (2018), s. 71-88 ISSN 0037-0738 R&D Projects: GA ČR(CZ) GA14-18183S Institutional support: RVO:61388980 ; RVO:67985831 Keywords : Bottom redox conditions * Geochemistry * Palaeoceanography * Spectral reflectance * Pragian stage * Red pelagic carbonates * Trophic levels Subject RIV: DD - Geochemistry; DB - Geology ; Mineralogy (GLU-S) OBOR OECD: Geology; Mineralogy (GLU-S) Impact factor: 2.373, year: 2016

  16. Transport and Retention of Nitrogen, Phosphorus and Carbon in North America’s Largest River Swamp Basin, the Atchafalaya River Basin

    OpenAIRE

    Y. Jun Xu

    2013-01-01

    Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004) river discharge and water quality records from an upriver and a downriver location of the Atchafalaya River to quantify the inflow, outflow, and inflow–outflow mass balance of total Kjeldahl nitrogen (TKN = organic nitrogen + ammonia nitrogen), nitr...

  17. Anthropogenic and climatic controls on carbon and nitrogen exports from Mississippi river basin to Gulf of Mexico during 1800 - 2100: Implications for hypoxia and ocean acidification

    Science.gov (United States)

    Tian, H.; Yang, J.; Zhang, B.; Pan, S.; Lohrenz, S. E.; Cai, W. J.; He, R.; Xue, Z. G.; Lu, C.; Ren, W.; Huang, W. J.; Yao, Y.

    2016-02-01

    The enlarged size of dead zone in the Gulf of Mexico in 2015, resulting from high summer precipitation and nutrient runoff from agriculture and other human activities in Mississippi river basin, has aroused plenty of scientific attentions and public concerns. Although recent-decade patterns of water/carbon/nitrogen exports from the US land to Gulf of Mexico have been intensively investigated through gauge station monitoring and empirical-based modeling, our understanding of its historical and future long-term trends and the underlying mechanisms is still limited. Climate variability and change, land cover/land use change (e.g., cropland shift from eastern US to Midwest US) and evolving land management practices (e.g., nitrogen fertilizer use in corn belt) are all important drivers regulating interannual, decadal and century-long variability in riverine carbon and nitrogen exports. In this study, we explore river discharge and carbon/nitrogen exports from US drainage basins in a 300-year period covering both historical and future eras (1800 - 2100) and further quantify the contributions of climate, land use, nitrogen fertilizer use, and atmospheric chemistry by using a process-based land ecosystem model (DLEM) with networked river system incorporated. The results indicate that spatial distribution and shift of agricultural land is of critical importance in shaping land-to-aquatic mass flow and coastal water quality. Historical pattern and future scenarios of climate variability and change play an important role in the trend of water yield and enhanced inter-annual variations of river discharge and carbon/nitrogen exports. Atmospheric nitrogen deposition and agricultural nitrogen fertilizer uses in land ecosystem largely contributed to land-to-aquatic nitrogen exports. Our sensitivity analyses with DLEM suggest that precipitation in the basin as well as nitrogen fertilizer use in US corn belt are important determinants of nutrient export and hence the size of dead

  18. Drilling, Completion, and Data Collection Plans An Assessment of Geological Carbon Sequestration Options in the Illinois Basin: Phase III

    Energy Technology Data Exchange (ETDEWEB)

    Malkewicz, Nicholas; Kirksey, Jim; Finley, Robert

    2015-05-01

    Executive Summary The Illinois Basin – Decatur Project (IBDP) is managed by the Midwest Geological Sequestration Consortium (MGSC) and is led by the Illinois State Geological Survey (ISGS) at the University of Illinois. The project site is located on the Archer Daniels Midland Company (ADM) property in Decatur, Illinois, and is a fully integrated carbon capture and storage (CCS) project that uses CO₂ captured from the ethanol-producing fermentation process at the ADM corn-processing plant (Finley et. al., 2013). IBDP has a goal of injecting one million tonnes of CO₂ into the basal sands of the Mt. Simon Sandstone over a three-year period. This is a multifaceted project, and this report details the planning and results of the drilling, completions, well testing, log data acquisition, and the Health, Safety, and Environment (HSE) aspects of the project. Three deep wells were planned for the IBDP: • The injection well: Injection Well #1 (CCS1); • The monitoring well (both in-zone and above seal): Verification Well #1 (VW1); and • The geophone monitoring well: Geophysical Monitoring Well #1 (GM1). The detailed plans for these wells are attached to the appendices of this document. The wells were drilled successfully with little deviation from the original plans. The biggest change from the plan to execution was the need to adjust for larger-than-expected loss of circulation in the Potosi section of the Knox Formation. The completions reports also attached to this document detail the well constructions as they were actually built. Injectivity testing was carried out, and the perforating plans were adjusted based on the results. Additional perforations and acidizing were performed as a result of the injectivity testing. The testing plans are detailed in this report along with the actual testing results. The injectivity testing results were used in the modeling and simulation efforts. Detailed HSE plans were developed and implemented during the planning and

  19. An evaluation of the carbon sequestration potential of the Cambro-Ordovician Strata of the Illinois and Michigan basins

    Energy Technology Data Exchange (ETDEWEB)

    Leetaru, Hannes [Univ. of Illinois, Champaign, IL (United States)

    2014-12-01

    The studies summarized herein were conducted during 2009–2014 to investigate the utility of the Knox Group and St. Peter Sandstone deeply buried geologic strata for underground storage of carbon dioxide (CO2), a practice called CO2 sequestration (CCS). In the subsurface of the midwestern United States, the Knox and associated strata extend continuously over an area approaching 500,000 sq. km, about three times as large as the State of Illinois. Although parts of this region are underlain by the deeper Mt. Simon Sandstone, which has been proven by other Department of Energy-funded research as a resource for CCS, the Knox strata may be an additional CCS resource for some parts of the Midwest and may be the sole geologic storage (GS) resource for other parts. One group of studies assembles, analyzes, and presents regional-scale and point-scale geologic information that bears on the suitability of the geologic formations of the Knox for a CCS project. New geologic and geo-engineering information was developed through a small-scale test of CO2 injection into a part of the Knox, conducted in western Kentucky. These studies and tests establish the expectation that, at least in some locations, geologic formations within the Knox will (a) accept a commercial-scale flow rate of CO2 injected through a drilled well; (b) hold a commercial-scale mass of CO2 (at least 30 million tons) that is injected over decades; and (c) seal the injected CO2 within the injection formations for hundreds to thousands of years. In CCS literature, these three key CCS-related attributes are called injectivity, capacity, and containment. The regional-scale studies show that reservoir and seal properties adequate for commercial-scale CCS in a Knox reservoir are likely to extend generally throughout the Illinois and Michigan Basins. Information distinguishing less prospective subregions from more prospective fairways is included in

  20. Assessing the Effect of Timing of Availability for Carbon Dioxide Storage in the Largest Oil and Gas Pools in the Alberta Basin: Description of Data and Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Dahowski, Robert T.; Bachu, Stefan

    2007-03-05

    Carbon dioxide capture from large stationary sources and storage in geological media is a technologically-feasible mitigation measure for the reduction of anthropogenic emissions of CO2 to the atmosphere in response to climate change. Carbon dioxide (CO2) can be sequestered underground in oil and gas reservoirs, in deep saline aquifers, in uneconomic coal beds and in salt caverns. The Alberta Basin provides a very large capacity for CO2 storage in oil and gas reservoirs, along with significant capacity in deep saline formations and possible unmineable coal beds. Regional assessments of potential geological CO2 storage capacity have largely focused so far on estimating the total capacity that might be available within each type of reservoir. While deep saline formations are effectively able to accept CO2 immediately, the storage potential of other classes of candidate storage reservoirs, primarily oil and gas fields, is not fully available at present time. Capacity estimates to date have largely overlooked rates of depletion in these types of storage reservoirs and typically report the total estimated storage capacity that will be available upon depletion. However, CO2 storage will not (and cannot economically) begin until the recoverable oil and gas have been produced via traditional means. This report describes a reevaluation of the CO2 storage capacity and an assessment of the timing of availability of the oil and gas pools in the Alberta Basin with very large storage capacity (>5 MtCO2 each) that are being looked at as likely targets for early implementation of CO2 storage in the region. Over 36,000 non-commingled (i.e., single) oil and gas pools were examined with effective CO2 storage capacities being individually estimated. For each pool, the life expectancy was estimated based on a combination of production decline analysis constrained by the remaining recoverable reserves and an assessment of economic viability, yielding an estimated depletion date, or year

  1. Coal deposition in carbonate-rich shallow lacustrine systems: the Calaf and Mequinenza sequences (Oligocene, eastern Ebro Basin, NE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, L.; Saez, A.

    1987-05-01

    Two main coal-bearing sequences developed during the Oligocene in the Tertiary Ebro Basin, the Calaf (early Oligocene) and Mequinenza (late Oligocene) coal basins. Coal deposition took place in shallow marsh-swamp-lake complexes which sometimes became closed and evolved under warm climatic conditions with fluctuating humidity. These shallow lacustrine systems are closely interrelated with the terminal parts of the distributive fluvial systems which spread from the tectonically active Ebro basin margins. Laterally extensive lignite-bearing sequences, including rather thin, lenticular autochthonous and/or hypautochthonous coal seam with high ash and sulphur contents, characterized coal deposition in the shallow lacustrine systems. Coal seam geometry, which makes them nearly subeconomic, resulted from the tectonic instability during basin margin evolution and the sometimes closed, arid conditions under which the lacustrine systems evolved. High ash and sulphur contents resulted from the inadequate isolation of peat forming environments from clastic influx and from the very low acidity and sometimes high sulphate contents of the lacustrine waters. Coal exploration in shallow lacustrine sequences similar to those described here must take into account that the spread of coal-forming environments and maxima of coal deposition are usually coincident with lake expansions and retraction or shifting of the terminal fluvial zones interrelated with the lacustrine areas. 44 refs., 8 figs.

  2. Paleoenvironments, δ13C and δ18O signatures in the Neoproterozoic carbonates of the Comba Basin, Republic of Congo: Implications for regional correlations and Marinoan event

    Science.gov (United States)

    Préat, Alain; Delpomdor, Franck; Ackouala Mfere, Anna Perla; Callec, Yannick

    2018-01-01

    The Ediacaran Schisto-Calcaire Group is a ∼1300 m-thick succession belonging to the West Congo Supergroup in Central Africa. In the Comba Basin, it consists of three carbonate-dominated units defined as formations (SCI to SCIII) that are unconformably overlain by clastic deposits (Mpioka Group) interpreted as a molassic formation associated with the Panafrican Orogen. The underlying Upper Tillite and Cap Carbonate (SCIa) units, considered as markers of the Snowball Earth event were studied in three sections. We investigated the carbonates of the Schisto-Calcaire Group by defining new microfacies (MF1-MF7) and we performed C and O isotopic analyses in order to constraint the depositional and diagenetic events directly after the Marinoan interval. Stratigraphic variations of the stable isotopes are important in the series with lighter δ18O values (>1.5‰) than those of the Neoproterozoic ocean in the SCIc unit. According to regional stratigraphy a temperature effect can be dismissed and a freshwater surface layer is the origin of such negative δ18O values in this unit. The negative δ13C anomaly (-3.5‰ on average) of the Cap Carbonate is similarly to the δ18O values (-6.4‰ on average) in the range of the marine domain during postglacial sea level rise. The sample suite as a whole (SCII and SCIII formations) displays heavier δ18O and δ13C than those of the lower part (SCI unit) of the Schisto-Calcaire Group. The comparison with the Lower Congo (Democratic Republic of Congo) and Nyanga (Gabon) basins shows that the meteoric flushing in SCIc unit of the Schisto-Calcaire Group was regional and not local, and could be derived from a climatic evolution. Although an overall overprint is present, our isotopic relationships argue against overall diagenetic resetting of primary compositions and suggest that with careful examination combined with detailed petrographic analysis general depositional and diagenetic controls can be discerned in oxygen and carbon

  3. Population carbon budgets and the importance of the amphipod corophium volutator in the carbon transfer on a cumberland basin mudflat, upper bay of fundy, Canada

    Science.gov (United States)

    Hawkins, C. M.

    The importance of Corophium volutator in the carbon flux between microalgal primary producers and other trophic levels was evaluated from population carbon budgets. In all but 4 of 39 population carbon budgets the estimated consumption was sufficient to meet the demands of production and respiration combined. A carbon budget constructed for the period from May to September 1979 revealed that Corophium production accounted for 40% of the consumption, respiration for 25% and the remainder by difference was attributed to faecal waste. Consumption was equivalent to 27% of the "net" epibenthic microalgal primary production over the same time period. Marked temporal changes in Corophium abundance appear to influence rates of benthic microalgal primary production during summer. Concurrently, an approximate 20-fold increase in Corophium biomass provides a significant food resource for birds and fishes. This implies that Corophium occupies a key link in processes of carbon flux on mudflats in the upper reaches of the Bay of Fundy.

  4. Sources of carbon and nitrogen in streams draining urban catchments in the Geum River basin, Korea, based on multiple isotopic tracers and water chemistry

    Science.gov (United States)

    Shin, W.; Lee, D.; Lee, K.; Ryu, J.

    2011-12-01

    δ13CDIC, δ13CDOC, δ18ONO3- and δ15NNO3- along with chemical compositions were determined in three tributary streams (i.e., Gap, Yudeung and Daejeon streams) draining populated Daejeon metropolitan area of the Geum River basin, Korea. This study is aiming to elucidate the relative contribution of various anthropogenic and natural sources of carbon and nitrogen in urban streams. The river chemistry and isotopic compositions significantly varied with seasonal changes in water regimes. Due to East Asian monsoon climate, precipitation in the study area is concentrated during the wet period (Jul. ~ Sep.) thereby having increased stream discharges and a rapid turnover of subsurface waters. This seasonally concentrated precipitation results in relatively dry periods during Oct. through June with decreased stream discharges that consist of relatively high baseflow components. Compared to the dry periods, streams during the wet period exhibited lower EC, HCO3-, δ13CDIC, δ13CDOC and δ15NNO3-, but higher Si and NO3- concentrations. From the results, it is estimated that the dissolved inorganic carbon (DIC) was derived dominantly from sedimentary carbonates during dry periods but the proportion of silicate weathering products increased during the wet period. Dissolved organic carbon (DOC) was mainly allochthonous, and the input of young and labile organic materials from soils increased during the wet period. The increase of NO3- concentration during the wet period was due to the input of soil- and fertilizer-derived nitrates, while nitrates during dry periods were mostly derived from the manure and sewage. The results of this study can be used to assess and manage anthropogenic influences on carbon and nitrogen cycles in urban streams.

  5. Use of ``rock-typing`` to characterize carbonate reservoir heterogeneity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ikwuakor, K.C.

    1994-03-01

    The objective of the project was to apply techniques of ``rock-typing`` and quantitative formation evaluation to borehole measurements in order to identify reservoir and non-reservoir rock-types and their properties within the ``C`` zone of the Ordovician Red River carbonates in the northeast Montana and northwest North Dakota areas of the Williston Basin. Rock-typing discriminates rock units according to their pore-size distribution. Formation evaluation estimates porosities and pore fluid saturation. Rock-types were discriminated using crossplots involving three rock-typing criteria: (1) linear relationship between bulk density and porosity, (2) linear relationship between acoustic interval transit-time and porosity, and (3) linear relationship between acoustic interval transit-time and bulk density. Each rock-type was quantitatively characterized by the slopes and intercepts established for different crossplots involving the above variables, as well as porosities and fluid saturations associated with the rock-types. All the existing production was confirmed through quantitative formation evaluation. Highly porous dolomites and anhydritic dolomites contribute most of the production, and constitute the best reservoir rock-types. The results of this study can be applied in field development and in-fill drilling. Potential targets would be areas of porosity pinchouts and those areas where highly porous zones are downdip from non-porous and tight dolomites. Such areas are abundant. In order to model reservoirs for enhanced oil recovery (EOR) operations, a more localized (e.g. field scale) study, expanded to involve other rock-typing criteria, is necessary.

  6. Parameters determining the carbon isotopic composition of coal and fossil wood in the Early Miocene Oberdorf lignite seam (Styrian Basin, Austria)

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, A.; Sachsenhofer, R.F.; Gratzer, R.; Lucke, A.; Puttmann, W. [University of Leoben, Leoben (Austria)

    2002-07-01

    Petrographical and geochemical data of gelified and ungelified fossil wood from the Early Miocene Oberdorf lignite seam (Styrian Basin, Austria) provide evidence that the early diagenetic, aerobic degradation of wood by fungi may be followed by further decomposition under reducing conditions by the activity of anaerobic bacteria. Based on the molecular compositions of terpenoid hydrocarbons, the wood fragments in the lignite are identified as gymnosperms. The mean carbon isotope values found for gymnosperms and coals (-24.2 parts per thousand and -24.7 parts per thousand, respectively) confirm the results from biomarker analyses indicating that the peat-forming vegetation of the Oberdorf seam was dominated by gymnosperm taxa. The results obtained from the Early Miocene Oberdorf lignite indicate that the carbon isotope ratios of the coals are primarily affected by varying contributions of different parts of whole-plant tissue, due to their different isotopic and molecular compositions (e.g. epicuticular leaf waxes, resins, wood) and their different decay-resistance against the early diagenetic changes involved in organic matter decomposition. Carbon cycling during anoxic decomposition of plant-derived organic matter is assumed to affect the {delta}-{sup 13}C values of coal. {delta}-{sup 13}C Values of wood and extracted cellulose are affected only to a minor extent.

  7. No proof from carbon isotopes in the Francevillian (Gabon) and Onega (Fennoscandian shield) basins of a global oxidation event at 1980-2090 Ma following the Great Oxidation Event (GOE)

    Science.gov (United States)

    Weber, Francis; Gauthier-Lafaye, François

    2013-01-01

    Highly depleted C isotope composition of organic matters from the Onega (Fennoscandian shield) and Francevillian (Gabon) basins are differently interpreted. Kump et al. (2011) suggested the occurrence of a massive and global oxidation event during the period of 1980-2090 Ma, which follows the Great Oxidation Event (2450-2320 Ma) (Bekker et al., 2004). Inversely, Gauthier-Lafaye and Weber (2003) invoke the possible action of methanotrophic microorganisms to explain the δ13C values as low as -46‰ measured in the Franceville basin. Here we present the isotope data available in the Franceville basin in order to discuss these two interpretations. The lack of any δ13C correlation between organic matter and carbonate in the Franceville basin does not allow the consideration of a massive and global oxidation event.

  8. A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Erdlac, Richard J., Jr.

    2006-10-12

    Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities

  9. Southwestern Regional Partnership For Carbon Sequestration (Phase 2) Pump Canyon CO2- ECBM/Sequestration Demonstration, San Juan Basin, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Resources International

    2010-01-31

    Within the Southwest Regional Partnership on Carbon Sequestration (SWP), three demonstrations of geologic CO{sub 2} sequestration are being performed -- one in an oilfield (the SACROC Unit in the Permian basin of west Texas), one in a deep, unmineable coalbed (the Pump Canyon site in the San Juan basin of northern New Mexico), and one in a deep, saline reservoir (underlying the Aneth oilfield in the Paradox basin of southeast Utah). The Pump Canyon CO{sub 2}-enhanced coalbed methane (CO{sub 2}/ECBM) sequestration demonstration project plans to demonstrate the effectiveness of CO{sub 2} sequestration in deep, unmineable coal seams via a small-scale geologic sequestration project. The site is located in San Juan County, northern New Mexico, just within the limits of the high-permeability fairway of prolific coalbed methane production. The study area for the SWP project consists of 31 coalbed methane production wells located in a nine section area. CO{sub 2} was injected continuously for a year and different monitoring, verification and accounting (MVA) techniques were implemented to track the CO{sub 2} movement inside and outside the reservoir. Some of the MVA methods include continuous measurement of injection volumes, pressures and temperatures within the injection well, coalbed methane production rates, pressures and gas compositions collected at the offset production wells, and tracers in the injected CO{sub 2}. In addition, time-lapse vertical seismic profiling (VSP), surface tiltmeter arrays, a series of shallow monitoring wells with a regular fluid sampling program, surface measurements of soil composition, CO{sub 2} fluxes, and tracers were used to help in tracking the injected CO{sub 2}. Finally, a detailed reservoir model was constructed to help reproduce and understand the behavior of the reservoir under production and injection operation. This report summarizes the different phases of the project, from permitting through site closure, and gives the

  10. Paleoceanographic and paleoclimatic changes during the Plio-Pleistocene of the Salaverry Basin, Peru Offshore: Evidences from Benthic Foraminifera, Carbon and Oxygen Stable Isotope Geochemistry and distribution of Gypsum grains

    Science.gov (United States)

    Mukherjee, S. R.

    2016-02-01

    Benthic foraminiferal studies have been used significantly as potential proxy to understand paleoceanographic and paleoclimatic changes over geologic time. Our study was pursued to analyze core sediment samples of ODP Hole 680B, Salaverry Basin, Peru Offshore of intervals covering up to 90.5 mbsf of the Plio-Pleistocene age. Previous studies on micropaleontological analyses were performed only up to 45 mbsf. However present study was performed on Benthic Foraminiferal census count, stable carbon and oxygen isotopes, total organic carbon and Gypsum grains distribution analysis up to depth 90.5 mbsf and the obtained results has been used to understand paleoceanographic and paleoclimatic changes during the Plio-Pleistocene. Proxy data signifies the basin was aerially to sub-aerially exposed during the Pliocene (90.5 to 61.4 mbsf) due to intense compressional tectonic episodes which facilitated upliftment of outer shelf high as well as generation of folded structures parallel to the trench within the Salaverry and Lima Basins. This upliftment restricted incursion of marine water into the basin as evident by higher (>80%) abundances of gypsum grains and devoid of any foraminifera. Presence of foraminifera, gypsum within the sequence from 61.4 to 45 mbsf, signifies that the basin had undergone tectonic subsidence owing to normal faulting which had developed as the basin was under an extensional tectonic setting during the late Pliocene. This subsidence was also evidenced by the presence of mixed type of grains which signifies presence of slump deposits. Whereas sediments of younger sequence (above 45 mbsf) were deposited under the profound influence of climatically induced sea level fluctuations. Benthic foraminiferal species Bolivina seminuda which is a marker of Oxygen Minimum Zone had been flourished during this time. Their depleted oxygen isotopic values records the intervals of sea level rise during the climatic warmth which facilitated strong upwelling events and

  11. The social context of carbon sequestration: considerations from a multi-scale environmental history of the Old Peanut Basin of Senegal

    Science.gov (United States)

    Tschakert, P.; Tappan, G.

    2004-01-01

    This paper presents the results of a multi-scale investigation of environmental change in the Old Peanut Basin of Senegal throughout the 20th century. Based on historical accounts, ethnographies, aerial photos, satellite images, field and household surveys as well as various participatory research activities with farmers in selected villages, the study attempts to make explicit layered scales of analysis, both temporally and spatially. It shows that, despite some general trends of resource degradation in the Old Peanut Basin, local farming systems have embarked on different pathways of change to adapt to their evolving environment. It also illustrates that high diversity with respect to soil fertility management exists at the farm and household level. Finally, the paper proposes a farmer-oriented approach to carbon sequestration in order to integrate recommended technical options more efficiently into the complex and dynamic livelihoods of smallholders in dryland environments. This approach includes pathway-specific land use and management options at the level of farming systems and, at the level of individual households, a basket of possible practices from which farmers can choose depending on their multiple needs, capacities, and adaptive strategies to cope with risk and uncertainty.

  12. Biological and land use controls on the isotopic composition of aquatic carbon in the Upper Mississippi River Basin

    Science.gov (United States)

    Voss, Britta; Wickland, Kimberly P.; Aiken, George R.; Striegl, Rob

    2017-01-01

    Riverine ecosystems receive organic matter (OM) from terrestrial sources, internally produce new OM, and biogeochemically cycle and modify organic and inorganic carbon. Major gaps remain in the understanding of the relationships between carbon sources and processing in river systems. Here we synthesize isotopic, elemental, and molecular properties of dissolved organic carbon (DOC), particulate organic carbon (POC), and dissolved inorganic carbon (DIC) in the Upper Mississippi River (UMR) system above Wabasha, MN, including the main stem Mississippi River and its four major tributaries (Minnesota, upper Mississippi, St. Croix, and Chippewa Rivers). Our goal was to elucidate how biological processing modifies the chemical and isotopic composition of aquatic carbon pools during transport downstream in a large river system with natural and man-made impoundments. Relationships between land cover and DOC carbon-isotope composition, absorbance, and hydrophobic acid content indicate that DOC retains terrestrial carbon source information, while the terrestrial POC signal is largely replaced by autochthonous organic matter, and DIC integrates the influence of in-stream photosynthesis and respiration of organic matter. The UMR is slightly heterotrophic throughout the year, but pools formed by low-head navigation dams and natural impoundments promote a shift towards autotrophic conditions, altering aquatic ecosystem dynamics and POC and DIC composition. Such changes likely occur in all major river systems affected by low-head dams and need to be incorporated into our understanding of inland water carbon dynamics and processes controlling CO2 emissions from rivers, as new navigation and flood control systems are planned for future river and water resources management.

  13. Geochemistry and microfabrics of syndiagenetic strata-bound fluorite from Eschwege, Germany - Implications for fluorite formation and remobilization in Zechstein carbonates from the Lower Saxony Basin

    Science.gov (United States)

    Duschl, Florian; Wischhöfer, Philipp; Vollbrecht, Axel

    2017-04-01

    Core samples of Stassfurt carbonate rocks (Zechstein, Ca2) from various locations in the Lower Saxony Basin (LSB) often contain fluorite which occurs as pore filling cement, replacement fluorite, or as fault-related fracture mineralizations. Recent studies on fluorite geochemistry and fluid migration in the LSB suggest a sedimentary rather than a hydrothermal fluorite source for some of these deep-seated (> 2500 mbs) accumulations. Outcrop samples from lens-shaped and stratiform fluorite occurrences within oolithic limestone (Ca2) near Eschwege, Germany, give insight into syndiagenetic fluorite formation in Zechstein carbonates. They serve as a shallow-burial analogue for remobilized fluorite within deeply buried carbonate rocks of the LSB. Samples were studied using petrographic microscopy, hot-cathodoluminescence microscopy, and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five different fluorite types were identified: a first generation (I) is represented by a dark brownish to violet fluorite that replaced ooids during early diagenesis. As pressure increased during burial the replacement fluorite recrystallized forming white aggregates of parallel bar-shaped fluorite crystals (type II), type (III) consists of white fluorite grains with rectangular and mostly polygonal grain boundaries; type (IV) is a colorless to blueish pore-filling fluorite, and type (V) is a colorless fracture-hosted fluorite. In-situ LA-ICP-MS analyses of respective fluorite types revealed relatively low REE concentrations in general with Tb/Ca vs. Tb/La signatures that are typical for sediment-hosted fluorite. The REE distribution patterns reflect the processes of recrystallization and remobilization. Though stylolitization affected both host rock and replacement fluorite, only little fluorite remobilization did occur due to pressure solution. Geochemical analyses prove that fluorite formation was controlled by precipitation from a sedimentary parental fluid

  14. The Gela Basin pockmark field in the strait of Sicily (Mediterranean Sea: chemosymbiotic faunal and carbonate signatures of postglacial to modern cold seepage

    Directory of Open Access Journals (Sweden)

    M. Taviani

    2013-07-01

    Full Text Available The geo-biological exploration of a pockmark field located at ca. 800 m below sea level in the Gela basin (Strait of Sicily, Central Mediterranean provided a relatively diverse chemosymbiotic community and methane-imprinted carbonates. To date, this is the first occurrence of such a type of specialised deep-water cold-seep communities recorded from this key region, before documented in the Mediterranean as rather disjunct findings in its eastern and westernmost basins. The thiotrophic chemosymbiotic organisms recovered from this area include empty tubes of the vestimentiferan Lamellibrachia sp., loose and articulated shells of lucinids (Lucinoma kazani, Myrtea amorpha, vesicomyids (Isorropodon perplexum, and gastropods (Taranis moerchii. A callianassid decapod (Calliax sp. was consistently found alive in large numbers in the pockmark mud. Their post-mortem calcified parts mixed with molluscs and subordinately miliolid foraminifers form a distinct type of skeletal assemblage. Carbonate concretions display δ13C values as low as −40‰ PDB suggesting the occurrence of light hydrocarbons in the seeping fluids. Since none of the truly chemosymbiotic organisms was found alive, although their skeletal parts appear at times very fresh, some specimens have been AMS-14C dated to shed light on the historical evolution of this site. Lamellibrachiav and Lucinoma are two of the most significant chemosymbiotic taxa reported from various Mediterranean cold seep sites (Alboran Sea and Eastern basin. Specimens from station MEDCOR78 (pockmark #1, Lat. 36°46´10.18" N, Long. 14°01´31.59" E, 815 m below sea level provided ages of 11736 ± 636 yr cal BP (Lamellibrachia sp., and 9609.5 ± 153.5 yr cal BP (L. kazani. One shell of M. amorpha in core MEDCOR81 (pockmark #6, Lat 36°45´38.89" N, Long 14°00´07.58" E, 822 m below sea level provided a sub-modern age of 484 ± 54 yr cal BP. These ages document that fluid seepage at this pockmark site has been

  15. From outcrop and petrographic studies to basin-scale fluid flow modelling: The use of the Albanian natural laboratory for carbonate reservoir characterisation

    Science.gov (United States)

    Vilasi, Nadège; Malandain, Julien; Barrier, Laurie; Callot, Jean-Paul; Amrouch, Khalid; Guilhaumou, Nicole; Lacombe, Olivier; Muska, Kristaq; Roure, François; Swennen, Rudy

    2009-09-01

    The Albanian fold-and-thrust belt and the Peri-Adriatic Depression are well documented by means of seismic reflection profiles, GPS reference points, potential data, wells and outcrops. The continuous Oligocene to Plio-Quaternary sedimentary records help to constrain both the burial history of Mesozoic carbonate reservoirs, the timing of their deformation, and the coupled fluid flow and diagenetic scenarios. Since the mid-90s, the Albanian foothills were used as a natural laboratory to develop a new integrated methodology and work flow for the study of sub-thrust reservoir evolution, and to validate on real case studies the use of basin modelling tools as well as the application of new analytical methods for the study petroleum systems in tectonically complex areas. The integration of the interactions between petrographic and microtectonic studies, kinematic, thermal and fluid flow basin modelling, is described in detail. The fracturing of the reservoir intervals has a pre-folding origin in the Albanides and relates to the regional flexuring in the foreland. The first recorded cement has a meteoric origin, implying downward migration and the development of an earlier forebulge in the Ionian Basin. This fluid, which precipitates at a maximum depth of 1.5 km, is highly enriched in strontium, attesting for important fluid-rock interaction with the Triassic evaporites, located in diapirs. From this stage, the horizontal tectonic compression increases and the majority of the fluid migrated under high pressure, characterised by brecciated and crack-seal vein. The tectonic burial increased due to the overthrusting, that is pointed out by the increase of the precipitation temperature of the cements. Afterwards, up- or downward migration of SO 42-, Ba 2+ and Mg 2+-rich fluids, which migrated probably along the décollement level, allows a precipitation in thermal disequilibrium. This period corresponds to the onset of the thrusting in the Ionian Zone. The last stage

  16. Scale Invariant Power Laws Capture the 3-D Coupling Between Water, Energy and Carbon Budgets Across River Basins of Increasing Horton-Strahler Orders in the Andes-Amazon System

    Science.gov (United States)

    Poveda, G.; Zapata, A. F.

    2016-12-01

    The Andes-Amazon system exhibits complex interactions and feedbacks between hydrological, ecological, biogeochemical and climatic factors in a broad range of temporal and spatial scales. We aim to understand the coupling existing between water, energy and carbon budgets in the Andes-Amazon system, by performing a systematic study of the system for river basins of increasing Horton-Strahler orders, from the headwaters of the Amazon River basin along the Andes (order ω=1 river sub-basins) to the low-lying larger river sub-basins (order ω=10). To that end, this works introduces a 3-D generalization of the Budyko framework that aims to link the water, energy, and Carbon budgets in river basins. The newly proposed 3-D non-dimensional space is defined by: (1) the ratio between long-term mean values of Actual Evapotranspiration (AET) and Precipitation (P), α=AET/P, representing the water balance; (2) the ratio between AET and Potential Evapotranspiration (PET), β=AET/PET, representing the energy balance; and (3) the ratio between AET and Aboveground Net Primary Productivity, δ=AET/ANPP, representing the carbon budget. We use a 3" Digital Elevation Model (DEM), which allows defining river basins with Horton-Strahler orders from 1 to 10. The long-term water, energy, and carbon budgets are estimated for increasing values of the Horton-Strahler orders during the period 1987-2007. Data sets pertaining to the water balance come from ORE-HYBAM, potential evapotranspiration (PET) from GLEAM (Global Land-surface Evaporation: the Amsterdam Methodology). Data for the energy budget are from the Surface Radiation Budget (SRB). Data for the Carbon budget (annual mean net primary productivity, ANPP, gross primary productivity, GPP, and respiration rates, Rr, come from AMAZALERT and ORCHEDEE (Organizing Carbon and Hydrology In Dynamic EcosystEms), as well as from Flux Tower Data and the LBA project. Our results show that scale invariant power-laws emerge to capture the three 2-D

  17. Sedimentology and geochemistry of carbonates diagenesis. Application to the Malm of the eastern edge of the Paris basin; Sedimentologie et geochimie de la diagenese des carbonates. Application au Malm de la Bordure Est du Bassin de Paris

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, B

    2001-12-01

    The important heterogeneity of neritic carbonates reflects: 1 - the facies characteristics of the initial sediments, linked with the diversity of sedimentation environments, and 2 - the post-sedimentation diagenesis characteristics. The aim of this work is to explore this heterogeneity using the {delta}{sup 18}O isotopic signal. A three step pluri-disciplinary approach with different observation scales is established: 1 - a sedimentology study (facies inventory, paleo-environment variations, stratigraphic cycles), 2 - an inventory and chronology of the diagenesis phases and products which have modified he initial sediments, and 3 - a geochemical approach based on the {delta}{sup 18}O signal. This last step combines ionic microprobe measurements performed on separated phases and measurements performed on the whole rock carbonated phase. The carbonate formations under study correspond to the HTM102 borehole made by the ANDRA in the Malm of the eastern edge of the Paris basin. For the stratigraphic approach, some field analogues have been studied (Pagny-sur-Meuse and Gudmont-Villiers sections). (J.S.)

  18. CHRONOLOGICAL CONSTRAINTS ON FLUID CIRCULATION IN MESOZOIC FORMATIONS OF THE EASTERN PART OF THE PARIS BASIN INFERRED FROM U-Pb DATING OF SECONDARY INFILLING CARBONATES

    Science.gov (United States)

    Pisapia, C.; Deschamps, P.; Hamelin, B.; Buschaert, S.

    2009-12-01

    The French agency for nuclear waste management (ANDRA) developed an Underground Research Laboratory in the Mesozoic formations of Eastern part of the Paris Basin (France) to assess the feasibility of a high-level radioactive wastes repository in sedimentary formations. The target host formation is a low-porosity detrital argillite (Callovo-Oxfordian) embedded between two shelf limestones formations (of Bajocian-Bathonian and Oxfordian-Kimmeridgian ages). These formations are affected by fracture networks, likely inherited mainly from the Eocene-Oligocene extension tectonics, also responsible of the Rhine graben formation in the same region. The limestones have very low permeability, the primary and secondary porosity being infilled by secondary carbonated minerals. The inter-particle porosity is filled with euhedral calcite spar cements. Similarly, macro-cavities and connected micro-fractures are almost sealed by euhedral calcite. Geochemical evidences (δ18O) suggest that the secondary carbonates likely derived from a common parent fluid (Buschaert et al., 2004, Appl. Geochem. (19) 1201-1215p). This late carbonated precipitation phase is responsible for the intense cementation of the limestone formations and bears witness of a major phase of fluids circulation that marked the late diagenetic evolution of the system. Knowledge of the chronology of the different precipitation phases of secondary minerals is thus of critical importance in order to determine the past hydrological conditions of the geological site. The aim of this study is to provide chronological constraints on the secondary carbonate mineral precipitation using U/Th and U/Pb methods. Analyses are performed on millimeter to centimeter scale secondary calcites collected within fractures outcropping in the regional fault zone of Gondrecourt and in cores from the ANDRA exploration-drilling program. Preliminary U-Th analyses obtained on secondary carbonates from surface fractures infillings yield secular

  19. Water-quality assessment of the eastern Iowa basins- nitrogen, phosphorus, suspended sediment, and organic carbon in surface water, 1996-98

    Science.gov (United States)

    Becher, Kent D.; Kalkhoff, Stephen J.; Schnoebelen, Douglas J.; Barnes, Kimberlee K.; Miller, Von E.

    2001-01-01

    Twelve sites on streams and rivers in the Eastern Iowa Basins study unit were sampled monthly and during selected storm events from March 1996 through September 1998 to assess the occurrence, distribution, and transport of nitrogen, phosphorus, suspended sediment, and organic carbon as part of the U.S. Geological Survey’s National Water-Quality Assessment Program. One site was dropped from monthly sampling after 1996. Dissolved nitrogen and phosphorus were detected in every water sample collected. Nitrate accounted for 92 percent of the total dissolved nitrogen. About 22 percent of the samples had nitrate concentrations that exceeded the U.S. Environmental Protection Agency’s maximum contaminant level of 10 milligrams per liter as nitrogen for drinking-water regulations. The median concentration of total dissolved nitrogen for surface water in the study unit was 7.2 milligrams per liter. The median total phosphorus concentration for the study unit was 0.22 milligram per liter. About 75 percent of the total phosphorus concentrations exceeded the U.S. Environmental Protection Agency recommended total phosphorus concentration of 0.10 milligram per liter or less to minimize algal growth. Median suspended sediment and dissolved organic-carbon concentrations for the study unit were 82 and 3.5 milligrams per liter, respectively.

  20. Stratigraphic modeling of sedimentary basins

    Energy Technology Data Exchange (ETDEWEB)

    Aigner, T. (Shell Research B. V., Rijswijk (Netherlands)); Lawrence, D.T. (Shell Development Co., Houston, TX (USA))

    1990-11-01

    A two-dimensional stratigraphic forward model has been successfully applied and calibrated in clastic, carbonate, and mixed clastic/carbonate regimes. Primary input parameters are subsidence, sea level, volume of clastics, and carbonate growth potential. Program output includes sequence geometries, facies distribution lithology distribution, chronostratigraphic plots, burial history plots, thermal and maturity histories, and crossplots. The program may be used to predict reservoir distribution, to constrain interpretations of well and seismic data, to rapidly test exploration scenarios in frontier basins, and to evaluate the fundamental controls on observed basin stratigraphy. Applications to data sets from Main Pass (US Gulf Coast), Offshore Sarawak (Malaysia), Rub'al Khali basin (Oman), Paris basin (France), and Baltimore Canyon (US East Coast) demonstrate that the program can be used to simulate stratigraphy on a basin-wide scale as well as on the scale of individual prospects.

  1. Gas sources of the YN2 gas pool in the Tarim Basin - Evidence from gas generation and methane carbon isotope fractionation kinetics of source rocks and crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Tian, H.; Gan, H.J. [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Xiao, X.M. [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Wilkins, R.W.T. [CSIRO Petroleum, P. O. Box 136, North Ryde, NSW (Australia); Li, X.Q. [Key Laboratory of Coal Resources, Ministry of Education, China University of Mining and Technology, Beijing 100083 (China)

    2007-01-15

    The YN2 gas pool in the eastern Tarim basin has been believed to be an accumulation of gases resulting from oil-cracking. However, this gas source model cannot explain such geochemical characteristics of the natural gases as heavier carbon isotope values ({delta}{sup 13}C{sub 1}=-37.5 per mille to -36.2 per mille; {delta}{sup 13}C{sub 2}=-34.7 per mille to -30.9 per mille) and high content of nitrogen gas (15.5% on average). In this study, we performed pyrolysis experiments on typical source rock and crude oil samples selected from the basin, evaluated their kinetic parameters of gas generation and methane carbon isotopic fractionation, and extrapolated them to geological conditions. The results show that neither kerogen-cracking gas nor oil-cracking gas can act as the single gas source of the YN2 gas pool. By contrast, a mixing model of 55% kerogen-cracking gas and 45% oil-cracking gas results in an excellent match with the geochemical characteristics of the gas pool. The gas condensate from the YN2 gas pool originated from the cracking of oils in mid-upper Ordovician strata, and the nitrogen gas was mainly derived from the cracking of kerogen in Cambrian-lower Ordovician mudstones in the Yingjisu depression center during the very high level of maturation. The YN2 gas pool went through three stages of formation: (1) oils from Cambrian-lower Ordovician source rocks accumulated in Cambrian and Ordovician reservoirs during the middle Ordovician, and gases were generated from both kerogen and paleo-oil pools in the Cambrian-lower Ordovician strata during late Ordovician to early Devonian; (2) gases leaked during either late Devonian to Triassic due to uplifting, or late Jurassic due to intense faulting activity in this area; (3) gases were regenerated from the late cracking of kerogen in the Cambrian-lower Ordovician strata as well as from oil-cracking in mid-upper Ordovician reservoirs with rapid subsidence after the Cretaceous. The two types of gas mixed and

  2. The transformation of organic carbon during river-groundwater exchange: An example from the Murray-Darling Basin

    Science.gov (United States)

    Keshavarzi, M.; Baker, A.; Andersen, M. S.; Kelly, B. F. J.

    2016-12-01

    Groundwater systems connected to rivers can act as carbon sinks and sources, but little is known about the distribution, transformation, and retention of organic carbon in rivers connected to aquifers as few studies are available. The characterisation of dissolved organic matter (DOM) using optical absorbance in connected water systems has potential to provide novel insights about the organic component of carbon fluxes. Here, the optical absorbance of the river and groundwater samples is investigated in a river reach that is hydraulically connected to an adjoining alluvial and karst aquifer system, within a semi-arid agricultural catchment in New South Wales, Australia. Water samples were collected from the river and groundwater within monitoring boreholes and intercepted by caves. These water samples were analysed for absorbance, dissolved organic carbon (DOC) and inorganic chemical constituents. Groundwater samples collected close to the river have DOM characteristics similar to the river water, indicating losing conditions. While, groundwater samples collected further away from the river have lower DOC and absorbance, higher SUVA, and a lower and more variable spectral slope, compared to the river. We infer that this change in DOM character reveals the presence of sedimentary OM, which provides a source of relatively high molecular weight DOM that is subsequently transformed. In a dry period, when there was low flow in the river, three downstream river-water samples exhibited low absorbance and spectral slope similar to the groundwater, while the contemporaneous upstream river-water samples had higher absorbance and spectral slope. This suggests gaining conditions and a contribution of groundwater organic carbon into the river. It is concluded that optical analyses can be used to study organic carbon fluxes to differentiate and quantify the source of organic matter, and identify losing and gaining streams.

  3. Preliminary Pliocene-Pleistocene Stable-Isotope and Paleosol Data From the Fish Creek- Vallecito Basin, Southern California: Insights Into Paleoclimate From Pedogenic Carbonate

    Science.gov (United States)

    Peryam, T. C.; Dorsey, R. J.; Bindeman, I.; Housen, B.; Palandri, J.

    2008-12-01

    In this study we use detailed measurements and isotopic analyses of paleosols in the Fish Creek-Vallecito basin (FCVB), southern California, to interpret changes in Pliocene-Pleistocene paleoclimate in the area. The FCVB currently lies in a hyperarid rain shadow (MAP = 15-17 cm) formed by the Peninsular Ranges. The timing of Peninsular Range uplift is not known, although recent work suggests it could have occurred as recently as early Pleistocene (Mueller et al., 2006). In the FCVB, abundant paleosols are exposed in a thick, tilted stratigraphic section that accumulated in the hanging wall of the West Salton detachment fault. New high-resolution magnetostratigraphic dating allows us to determine the age of paleosol horizons to within an average of ∓ 0.06 m.y.. Pedogenic carbonate nodules from 23 horizons ranging in age from 3.7 to 1.0 Ma, spanning a thickness of 2.5 km, were analyzed for oxygen and carbon isotopic compositions on a Gasbench and MAT 253 mass spectrometer. The data reveal an increase in carbonate δ18O values at about 2.5-3.0 Ma, from -10.5 ∓ 0.1 ‰ to -9.2 ‰ ∓ 0.2 ‰ (VPDB). Pedogenic carbonate δ13C values vary between -10.4 ‰ and -3.8 ‰ (VPDB) with no apparent trend. A total of forty-nine paleosols were described in the study interval. Most paleosols have shallow carbonate (Bk) horizons and thin, poorly-developed A horizons. Our finding of an increase in δ18O corresponds broadly to a previous study of fossil horse teeth (Brogenski, 2001), which recorded a 2 ‰ increase in δ18O in meteoric water at about 2 Ma. Preliminary recalculation of Brogenski's fossil site ages suggests that the change in δ18O occurred earlier than previously reported, around 2.4 Ma. The increase in δ18O at 2.5-3.0 Ma coincides with a global climate change caused by the onset of northern hemisphere glaciation, and may reflect (1) an increase in enriched Pacific Ocean-derived storms and decrease in the concentration of isotopically depleted monsoonal sources

  4. ORCHILEAK (revision 3875): a new model branch to simulate carbon transfers along the terrestrial-aquatic continuum of the Amazon basin

    Science.gov (United States)

    Lauerwald, Ronny; Regnier, Pierre; Camino-Serrano, Marta; Guenet, Bertrand; Guimberteau, Matthieu; Ducharne, Agnès; Polcher, Jan; Ciais, Philippe

    2017-10-01

    Lateral transfer of carbon (C) from terrestrial ecosystems into the inland water network is an important component of the global C cycle, which sustains a large aquatic CO2 evasion flux fuelled by the decomposition of allochthonous C inputs. Globally, estimates of the total C exports through the terrestrial-aquatic interface range from 1.5 to 2.7 Pg C yr-1 (Cole et al., 2007; Battin et al., 2009; Tranvik et al., 2009), i.e. of the order of 2-5 % of the terrestrial NPP. Earth system models (ESMs) of the climate system ignore these lateral transfers of C, and thus likely overestimate the terrestrial C sink. In this study, we present the implementation of fluvial transport of dissolved organic carbon (DOC) and CO2 into ORCHIDEE (Organising Carbon and Hydrology in Dynamic Ecosystems), the land surface scheme of the Institut Pierre-Simon Laplace ESM. This new model branch, called ORCHILEAK, represents DOC production from canopy and soils, DOC and CO2 leaching from soils to streams, DOC decomposition, and CO2 evasion to the atmosphere during its lateral transport in rivers, as well as exchange with the soil carbon and litter stocks on floodplains and in swamps. We parameterized and validated ORCHILEAK for the Amazon basin, the world's largest river system with regard to discharge and one of the most productive ecosystems in the world. With ORCHILEAK, we are able to reproduce observed terrestrial and aquatic fluxes of DOC and CO2 in the Amazon basin, both in terms of mean values and seasonality. In addition, we are able to resolve the spatio-temporal variability in C fluxes along the canopy-soil-water continuum at high resolution (1°, daily) and to quantify the different terrestrial contributions to the aquatic C fluxes. We simulate that more than two-thirds of the Amazon's fluvial DOC export are contributed by the decomposition of submerged litter. Throughfall DOC fluxes from canopy to ground are about as high as the total DOC inputs to inland waters. The latter

  5. Marine vertebrates from the Santonian coastal carbonates of northwestern Germany - a tool for the reconstruction of a Proto- North Sea Basin intertidal dinosaur-exchange bridge

    Science.gov (United States)

    Diedrich, Cajus G.; Scheer, Udo

    2015-09-01

    A diverse vertebrate fauna, dominated by shark teeth, is recorded from conglomerates within the limestones of the Upper Cretaceous (Santonian) Burgsteinfurt Formation of northwestern Germany. The conglomerate beds comprise carbonatic, glauconitic and phosphate nodules, as well as Triassic, Jurassic and Cretaceous extraclasts. The Burgsteinfurt Formation conglomerates contain fining-upwards parasequences 2-20 cm in thickness, interpreted as tempestite layers within a unit formed by larger-scale Milankovitch Cycles. The presence of the inoceramid Sphenoceramus patootensis and belemnite Gonioteuthis granulata indicate a late Santonian age for the unit. The studied vertebrate fauna from the Weiner Esch locality consists of 20 selachian species (14 macroselachians and 6 microselachians), a few teleosts, rare marine mosasaur remains, and one tooth from a theropod dinosaur. 95% of the vertebrates in the assemblage are depositionally autochthonous, with the remaining material reworked from older underlying Cenomanian-Coniacian (lower Upper Cretaceous) limestones. On the basis of observed sedimentary structures, the scarcity of deep-sea selachians, and the dominance of the Mitsukurinidae (59% of the preserved shark fauna) in the fossil assemblage, the unit is interpreted as a shallow (0-3 metres deep), subtidal, nearshore environment, or even subaerial carbonate-sand islands, located on the southern margin of a submarine swell. The presence of a Santonian theropod in this deposit, and other dinosaur records in northern Germany, together support the interpretation of a short-lived uplift event with strong upwelling influence for the Northwestphalian-Lippe submarine swell north of the Rhenish Massif in the southern Proto- North Sea Basin. A new migration model for dinosaurs moving along carbonate coasts or intertidal zones of shallow carbonate-sand islands in Central Europe is presented, which may explain the scattered distribution of dinosaur remains across Europe in the

  6. Initial Characterization of Carbon Metabolism in Iron Oxidizing Microbial Communities of Acidic Hot Springs in Norris Geyser Basin, Yellowstone National Park

    Science.gov (United States)

    Kreuzer, H. W.; Jennings, R. D.; Whitmore, L.; Inskeep, W. P.; Moran, J.

    2012-12-01

    Norris Geyser Basin in Yellowstone National Park is home to several acidic, sulfidic hot springs. Visual inspection of the springs reveals distinct geochemical regions starting with a sulfur deposition zone followed by a transition to iron oxide deposition downstream. The microbial communities in the iron oxidation zones are dominated by Archaea, including several members that appear to define previously unrecognized taxa. Abiotic iron oxidation rates are very slow at these temperatures (typically ~ 65-70 oC) and pH's (typically ~3). Therefore, the relatively rapid iron oxide deposition rate strongly suggests the process is microbially mediated, and an organism previously isolated from these springs, Metallosphaera yellowstonensis, has been shown to oxide iron in culture. M. yellowstonensis has been observed in the all microbial communities analyzed in the iron oxidizing zones of these springs, though metagenomic profiling suggests it constitutes only ~20% of the community membership. When we began our studies of C flow in the iron-oxidizing community, no C source had been demonstrated. Observed potential carbon sources in the springs include dissolved inorganic carbon, dissolved organic carbon, and methane, as well as random inputs of heterotrophic carbon in the forms of insect carcasses, pine needles, and animal scat. The temperatures in the iron oxidation zones are above the photosynthetic upper temperature limit, thus precluding photosynthetic-based autotrophy within the community itself. We are employing geochemical and stable isotope techniques to assess carbon inventories in the system. We have demonstrated that M. yellowstonensis as well as excised samples of iron oxide mat communities can fix CO2, and our estimated isotopic fractionation factor is consistent with the 3-hydroxypropionate 4-hydroxybutyrate pathway. Genes of this pathway have been identified in the M. yellowstonensis genome. We have tentatively identified small amounts of organic compounds

  7. Post-Glacial Climate Forcing of Surface Processes in the Ganges-Brahmaputra Basin and Implications for the Global Carbon Cycle

    Science.gov (United States)

    Hein, C. J.; Galy, V.; France-Lanord, C.; Galy, A.; Kudrass, H. R.; Peucker-Ehrenbrink, B.

    2016-12-01

    Silicate weathering coupled with carbonate precipitation and organic carbon (OC) burial in marine sediments are the primary mechanisms sequestering atmospheric CO2 over a range of timescales. The efficiency of both processes has long been mechanistically linked to climate: increased atmospheric CO2 sequestration under warm/wet conditions acts as a negative feedback, thereby contributing to global climate regulation. Over glacial-interglacial timescales, climate has been proposed to control the export rate of terrestrial silicate weathering products and terrestrial OC to river-dominated margins, as well as the rates of chemical weathering (i.e., the efficiency of carbon sequestration). Focused on the Ganges-Brahmaputra drainage basin, this study quantifies the relative role of climate change in the efficiency of silicate weathering and OC burial following the last glacial maximum. Stable hydrogen (δD) and carbon (δ13C) isotopic compositions of terrestrial plant wax compounds preserved in the Bengal Fan channel-levee system capture variations in the strength of the Indian summer monsoon and vegetation dynamics. Specifically, a 40‰ shift in δD and a 4‰ shift in both bulk OC and plant wax δ13C values between the late glacial and mid-Holocene, followed by a return to more intermediate values during the late Holocene, correlate well with regional post-glacial paleoclimate records. Sediment provenance proxies (Sr, Nd isotopic compositions) reveal that these changes coincided with a focusing of erosion on the southern flank of the Himalayan range during periods of greater monsoon strength and enhanced sediment discharge. However, OC loading, and thus carbon burial efficiency, in the Bengal Fan remained constant through time, demonstrating the primacy of physical erosion and climate-driven sediment export in marine OC sequestration. In contrast, a gradual increase in K/Si* and Ca/Si, and decrease in H2O+/Si*, throughout the study period may demonstrate the

  8. USGS National and Global Oil and Gas Assessment Project - North-Central Montana and Williston Basin Provinces, Heath Formation Assessment Unit Boundaries

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is...

  9. Stable Carbon Isotope Enrichment Before Late Miocene and Its Iimplication for Landscape Change in the Amazon Basin

    Science.gov (United States)

    Lee, Y. I.; Kim, D.; Hyeong, K.; Chan Min, Y.

    2016-12-01

    The appearance and development of C4 plants in the Late Miocene is well-established by various lines of evidence including stable carbon isotope data, yet the stable carbon isotope change before the global vegetation change has not been reported. Prior to the C4 plant expansion, the ecosystem may have been composed of C3 plants. Here we present the content and stable carbon isotope record of black carbon (BC) in a 470-cm-long piston core retrieved from the northeastern equatorial Pacific. Although suitable age dating method is lacking for the studied core, correlation of clay mineral composition, BC content, and stable carbon isotope data with a nearby well-studied core (Kim et al., submitted) at the same latitude suggests that the studied core contains sediment older than 15 Ma (330 cm in depth) and possibly back to 25 Ma, much prior to the major diversification of C4 plants. The older sediment was derived from Southern Hemisphere. The δ13C value of BC in the oldest sediment shows a relatively high value ( -22.7 ‰ on average), similar to that of C4 expansion event, and then decreases with time till reaching normal δ13C value of C3-dominated environment (-25.3 ‰ on average) around 13 Ma. This relatively high δ13C value reflects the presence of specific ecosystem, likely Pebas wetland that dominated western Amazonia before 17 Ma, and decreasing δ13C value suggests subsequent gradual development of closed-forest ecosystem. The BC content shows an abrupt increase around 400 cm, suggesting a significant aridity event in South America. Uplift of the North Andean region at 23 Ma seems to be the likely cause of such aridity event. From these observations, we argue that by comparing with the well-studied core data environmental record provided by BC data can be used for approximate age dating of deep-sea core sediment lacking appropriate dating tools, and that carbon isotope data before C4 development event may also provide information about specific regional

  10. Carbon dioxide and hydrogen sulfide degassing and cryptic thermal input to Brimstone Basin, Yellowstone National Park, Wyoming

    Science.gov (United States)

    Bergfeld, D.; Evans, William C.; Lowenstern, J. B.; Hurwitz, S.

    2012-01-01

    Brimstone Basin, a remote area of intense hydrothermal alteration a few km east of the Yellowstone Caldera, is rarely studied and has long been considered to be a cold remnant of an ancient hydrothermal system. A field campaign in 2008 confirmed that gas emissions from the few small vents were cold and that soil temperatures in the altered area were at background levels. Geochemical and isotopic evidence from gas samples (3He/4He ~ 3RA, δ13C-CO2 ~ − 3‰) however, indicate continuing magmatic gas input to the system. Accumulation chamber measurements revealed a surprisingly large diffuse flux of CO2 (~ 277 t d-1) and H2S (0.6 t d-1). The flux of CO2 reduces the 18O content of the overlying cold groundwater and related stream waters relative to normal meteoric waters. Simple isotopic modeling reveals that the CO2 likely originates from geothermal water at a temperature of 93 ± 19 °C. These results and the presence of thermogenic hydrocarbons (C1:C2 ~ 100 and δ13C-CH4 = − 46.4 to − 42.8‰) in gases require some heat source at depth and refute the assumption that this is a “fossil” hydrothermal system.

  11. Upper Campanian–Maastrichtian nannofossil biostratigraphy and high-resolution carbon-isotope stratigraphy of the Danish Basin

    DEFF Research Database (Denmark)

    Thibault, Nicolas Rudolph; Harlou, Rikke; Schovsbo, Niels

    2012-01-01

    High-resolution carbon isotope stratigraphy of the upper Campanian – Maastrichtian is recorded in the Boreal Realm from a total of 1968 bulk chalk samples of the Stevns-1 core, eastern Denmark. Isotopic trends are calibrated by calcareous nannofossil bio-events and are correlated with a lower...... of dinoflagellate biostratigraphy and d13C stratigraphy between Stevns-1 and the Global boundary Standard Stratotype-section and Point at Tercis les Bains (SW France), allowing the identification of new chemical and biostratigraphic markers that provide a precise placement of the stage boundary on a regional scale...

  12. Impacts of brown carbon from biomass burning on surface UV and ozone photochemistry in the Amazon Basin

    KAUST Repository

    Mok, Jungbin

    2016-11-11

    The spectral dependence of light absorption by atmospheric particulate matter has major implications for air quality and climate forcing, but remains uncertain especially in tropical areas with extensive biomass burning. In the September-October 2007 biomass-burning season in Santa Cruz, Bolivia, we studied light absorbing (chromophoric) organic or “brown” carbon (BrC) with surface and space-based remote sensing. We found that BrC has negligible absorption at visible wavelengths, but significant absorption and strong spectral dependence at UV wavelengths. Using the ground-based inversion of column effective imaginary refractive index in the range 305–368 nm, we quantified a strong spectral dependence of absorption by BrC in the UV and diminished ultraviolet B (UV-B) radiation reaching the surface. Reduced UV-B means less erythema, plant damage, and slower photolysis rates. We use a photochemical box model to show that relative to black carbon (BC) alone, the combined optical properties of BrC and BC slow the net rate of production of ozone by up to 18% and lead to reduced concentrations of radicals OH, HO2, and RO2 by up to 17%, 15%, and 14%, respectively. The optical properties of BrC aerosol change in subtle ways the generally adverse effects of smoke from biomass burning.

  13. Impacts of Brown Carbon from Biomass Burning on Surface UV and Ozone Photochemistry in the Amazon Basin

    Science.gov (United States)

    Mok, Jungbin; Krotkov, Nickolay A.; Arola, Antti; Torres, Omar; Jethva, Hiren; Andrade, Marcos; Labow, Gordon; Eck, Thomas F.; Li, Zhangqing; Dickerson, Russell R.; hide

    2016-01-01

    The spectral dependence of light absorption by atmospheric particulate matter has major implications for air quality and climate forcing, but remains uncertain especially in tropical areas with extensive biomass burning. In the September-October 2007 biomass-burning season in Santa Cruz, Bolivia, we studied light absorbing (chromophoric) organic or brown carbon (BrC) with surface and space-based remote sensing. We found that BrC has negligible absorption at visible wavelengths, but significant absorption and strong spectral dependence at UV wavelengths. Using the ground-based inversion of column effective imaginary refractive index in the range 305368nm, we quantified a strong spectral dependence of absorption by BrC in the UV and diminished ultraviolet B (UV-B) radiation reaching the surface. Reduced UV-B means less erythema, plant damage, and slower photolysis rates. We use a photochemical box model to show that relative to black carbon (BC) alone, the combined optical properties of BrC and BC slow the net rate of production of ozone by up to 18 and lead to reduced concentrations of radicals OH, HO2, and RO2 by up to 17, 15, and 14, respectively. The optical properties of BrC aerosol change in subtle ways the generally adverse effects of smoke from biomass burning.

  14. Impacts of brown carbon from biomass burning on surface UV and ozone photochemistry in the Amazon Basin

    Science.gov (United States)

    Mok, Jungbin; Krotkov, Nickolay A.; Arola, Antti; Torres, Omar; Jethva, Hiren; Andrade, Marcos; Labow, Gordon; Eck, Thomas F.; Li, Zhanqing; Dickerson, Russell R.; Stenchikov, Georgiy L.; Osipov, Sergey; Ren, Xinrong

    2016-11-01

    The spectral dependence of light absorption by atmospheric particulate matter has major implications for air quality and climate forcing, but remains uncertain especially in tropical areas with extensive biomass burning. In the September-October 2007 biomass-burning season in Santa Cruz, Bolivia, we studied light absorbing (chromophoric) organic or “brown” carbon (BrC) with surface and space-based remote sensing. We found that BrC has negligible absorption at visible wavelengths, but significant absorption and strong spectral dependence at UV wavelengths. Using the ground-based inversion of column effective imaginary refractive index in the range 305-368 nm, we quantified a strong spectral dependence of absorption by BrC in the UV and diminished ultraviolet B (UV-B) radiation reaching the surface. Reduced UV-B means less erythema, plant damage, and slower photolysis rates. We use a photochemical box model to show that relative to black carbon (BC) alone, the combined optical properties of BrC and BC slow the net rate of production of ozone by up to 18% and lead to reduced concentrations of radicals OH, HO2, and RO2 by up to 17%, 15%, and 14%, respectively. The optical properties of BrC aerosol change in subtle ways the generally adverse effects of smoke from biomass burning.

  15. Multiphase Calcite Cementation and Fluids Evolution of a Deeply Buried Carbonate Reservoir in the Upper Ordovician Lianglitag Formation, Tahe Oilfield, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Jiaqing Liu

    2017-01-01

    Full Text Available Oil and gas have been found in the Upper Ordovician Lianglitag Formation carbonates in the Tahe Oilfield, Tarim Basin, NW China. This study documents the origin of diagenetic fluids by using a combination of petrology, SIMS, fluid inclusion, and radiogenic isotope analysis. Six stages of calcite cements were revealed. C1-C2 formed in marine to early burial environments. C3 has relatively low δ18OVPDB values (−8.45‰ to −6.50‰ and likely has a meteoric origin. Meteoric water probably fluxed into aquifers during the Early Paleozoic and Late Paleozoic uplift. C4 has δ18OVPDB values typically 3‰ higher than those of C3, and probably formed during shallow burial. C5 displays relatively negative δ18OVPDB values (−8.26‰ to −5.12‰, and the moderate-to-high fluid-inclusion temperatures imply that it precipitated in burial environments. C6 shows homogenization temperatures (up to 200°C higher than the maximum burial and much lower salinities (<10.61 wt% NaCl, which may suggest that the fluid was deeply recycled meteoric water. The average 87Sr/86Sr ratios of fracture- and vug-filling calcite cements are much higher, indicative of incorporation of radiogenic Sr. Caves and fractures constitute the dominant reservoir spaces. A corresponding diagenesis-related reservoir evolution model was established that favors exploration and prediction.

  16. Food web of a confined and anthropogenically affected coastal basin (the Mar Piccolo of Taranto) revealed by carbon and nitrogen stable isotopes analyses.

    Science.gov (United States)

    Bongiorni, Lucia; Fiorentino, Federica; Auriemma, Rocco; Aubry, Fabrizio Bernardi; Camatti, Elisa; Camin, Federica; Nasi, Federica; Pansera, Marco; Ziller, Luca; Grall, Jacques

    2016-07-01

    Carbon and nitrogen stable isotope analysis was used to examine the food web of the Mar Piccolo of Taranto, a coastal basin experiencing several anthropogenic impacts. Main food sources (algal detritus, seaweeds, particulate organic matter (POM) and sediment organic matter (SOM)) and benthic and pelagic consumers were collected during two contrasting seasons (June and April), at four sites distributed over two inlets, and characterized by different level of confinements, anthropogenic inputs and the presence of mussels farming. δ(13)C values of organic sources revealed an important contribution of POM to both planktonic and benthic pathways, as well as the influence of terrigenous inputs within both inlets, probably due to high seasonal land runoff. Although δ(13)C of both sources and consumers varied little between sampling sites and dates, δ(15)N spatial variability was higher and clearly reflected the organic enrichment in the second inlet as well as the uptake of anthropogenically derived material by benthic consumers. On the other hand, within the first inlet, the isotopic composition of consumers did not change in response to chemical contamination. However, the impact of polluted sediments near the Navy Arsenal in the first inlet was detectable at the level of the macrobenthic trophic structure, showing high dominance of motile, upper level consumers capable to face transient conditions and the reduction of the more resident deposit feeders. We therefore underline the great potential of matching stable isotope analysis with quantitative studies of community structure to assess the effects of multiple anthropogenic stressors.

  17. Dissolved organic carbon content and characteristics in relation to carbon dioxide partial pressure across Poyang Lake wetlands and adjacent aquatic systems in the Changjiang basin.

    Science.gov (United States)

    Wang, Huaxin; Jiao, Ruyuan; Wang, Fang; Zhang, Lu; Yan, Weijin

    2016-12-01

    Dissolved organic carbon (DOC) plays diverse roles in carbon biogeochemical cycles. Here, we explored the link between DOC and pCO2 using high-performance size-exclusion chromatography (HPSEC) with UV254 detection and excitation emission matrix (EEM) fluorescence spectroscopy to determine the molecular weight distribution (MW) and the spectral characteristics of DOC, respectively. The relationship between DOC and pCO2 was investigated in the Poyang Lake wetlands and their adjacent aquatic systems. The results indicated significant spatial variation in the DOC concentrations, MW distributions, and pCO2. The DOC concentration was higher in the wetlands than in the rivers and lakes. pCO2 was high in wetlands in which the dominant vegetation was Phragmites australis, whereas it was low in wetlands in which Carex tristachya was the dominant species. DOC was divided into five fractions according to MW, as follows: super-low MW (SLMW, 40 kDa). Rivers contained high proportions of HMW and extremely low amounts of SLMW, whereas wetlands had relatively high proportions of SLMW. The proportion of SMW (SMWp) was particularly high in wetlands. We found that pCO2 significantly positively correlated with the proportion of IMW, and significantly negatively correlated with SMWp. These data improve our understanding of the MW of bioavailable DOC and its conversion to CO2. The present results demonstrate that both the content and characteristics of DOC significantly affect pCO2. pCO2 and DOC must be studied further to help understanding the role of the wetland on the regional CO2 budget. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Distribution and cycling of total organic carbon across the Almeria-Oran Front in the Mediterranean Sea: Implications for carbon cycling in the western basin

    Science.gov (United States)

    SempéRé, Richard; Dafner, Evgeny; van Wambeke, France; LefèVre, Dominique; Magen, CéDric; AllèGre, Sophie; Bruyant, Flavienne; Bianchi, Micheline; Prieur, Louis

    2003-11-01

    The dynamics of the total organic carbon (TOC) pool were studied during winter 1997-1998 in the Almeria-Oran jet-front (AOF) system. This system includes the modified Atlantic Jet, which spreads into the Mediterranean Sea from the Gibraltar Strait, its associated gyre, and the front between the Mediterranean and Atlantic waters. We determined TOC concentrations, bacterial production (BP), and primary production (PP) during field work, and labile dissolved organic carbon (l-DOC) and bacterial growth efficiency (BGE), which were calculated from biodegradation experiments. Our results showed that the geostrophic Atlantic Jet, which is the most dynamic area (horizontal speed of 80 cm s-1 in the upper 100 m flowing eastward), was characterized by low TOC stocks integrated in the first 100 m (6330-6990 mmol C m-2), a proportion of l-DOC of 5 ± 0.5%, a BGE of 15 ± 2% and moderate residence times of excess-TOC (42 ± 7 days). Higher TOC stocks were found in the surrounding areas, including the Mediterranean (7298-7400 mmol C m-2) and gyre waters (6718-8315 mmol C m-2) whereas l-DOC averaged 6 ± 0.9% and 15 ± 2%, respectively. BGE averaged 7 ± 1% in Mediterranean waters and 21 ± 3% in the gyre giving rise to slightly different excess-TOC residence times (28 ± 1 days in Mediterranean waters and 109 ± 30 days in the gyre). We estimated that the transport of TOC and excess-TOC within the Atlantic Jet averaged 8.04 ± 0.32 × 104 and 1.68 ± 0.32 × 104 mol C s-1, respectively.

  19. Do dynamic global vegetation models capture the seasonality of carbon fluxes in the Amazon basin? A data-model intercomparison.

    Science.gov (United States)

    Restrepo-Coupe, Natalia; Levine, Naomi M; Christoffersen, Bradley O; Albert, Loren P; Wu, Jin; Costa, Marcos H; Galbraith, David; Imbuzeiro, Hewlley; Martins, Giordane; da Araujo, Alessandro C; Malhi, Yadvinder S; Zeng, Xubin; Moorcroft, Paul; Saleska, Scott R

    2017-01-01

    To predict forest response to long-term climate change with high confidence requires that dynamic global vegetation models (DGVMs) be successfully tested against ecosystem response to short-term variations in environmental drivers, including regular seasonal patterns. Here, we used an integrated dataset from four forests in the Brasil flux network, spanning a range of dry-season intensities and lengths, to determine how well four state-of-the-art models (IBIS, ED2, JULES, and CLM3.5) simulated the seasonality of carbon exchanges in Amazonian tropical forests. We found that most DGVMs poorly represented the annual cycle of gross primary productivity (GPP), of photosynthetic capacity (Pc), and of other fluxes and pools. Models simulated consistent dry-season declines in GPP in the equatorial Amazon (Manaus K34, Santarem K67, and Caxiuanã CAX); a contrast to observed GPP increases. Model simulated dry-season GPP reductions were driven by an external environmental factor, 'soil water stress' and consequently by a constant or decreasing photosynthetic infrastructure (Pc), while observed dry-season GPP resulted from a combination of internal biological (leaf-flush and abscission and increased Pc) and environmental (incoming radiation) causes. Moreover, we found models generally overestimated observed seasonal net ecosystem exchange (NEE) and respiration (R e ) at equatorial locations. In contrast, a southern Amazon forest (Jarú RJA) exhibited dry-season declines in GPP and R e consistent with most DGVMs simulations. While water limitation was represented in models and the primary driver of seasonal photosynthesis in southern Amazonia, changes in internal biophysical processes, light-harvesting adaptations (e.g., variations in leaf area index (LAI) and increasing leaf-level assimilation rate related to leaf demography), and allocation lags between leaf and wood, dominated equatorial Amazon carbon flux dynamics and were deficient or absent from current model

  20. Stable carbon and nitrogen isotopic signatures of fauna associated with the deep-sea hydrothermal vent system of Guaymas Basin, Gulf of California

    Science.gov (United States)

    Soto, Luis A.

    2009-09-01

    Potential food sources and the trophic position of some of the most conspicuous faunal components (vent and non-vent) were examined in the deep-hydrothermal vent system of Guaymas Basin, in the Gulf of California using carbon and nitrogen stable isotope analyses. The isotopic signatures of 13 species collected by the DSRV Alvin and Nautile mostly from sulfide-influenced habitats were analyzed. The δ 13C of nine vent species had a wide range (-36.0‰ to -12.7‰), whereas the δ 15N values varied from -5.0‰ to+9.4‰. The dual isotopic approach allowed the recognition of two main groups containing vent-endemic fauna. One was represented by an assemblage of eight species associated with sulfide deposits, visually dominated by the siboglinid worm Riftia pachyptila and characterized by enriched δ 13C values (means -13.7‰ to -21.0‰). The second group included a single species, the bivalve Vesicomya gigas, an inhabitant of soft sediments, which had depleted δ 13C and δ 15N signatures (means -35.7‰ and -1.5‰). The galatheid Munidopsis alvisca is an exception among the species in the R. pachyptila aggregation, due to its depleted δ 13C (-26.4‰) and an intermediate δ 15N value (+5.5‰). Isotopic δ 13C and δ 15N signatures of four non-vent species exhibited mostly enriched δ 15N values (means δ 13C -27.8‰ to -13.6‰; δ 15N +14.5‰ to +17.9‰), expected for higher consumers and detritivores in a deep-sea food web. They may benefit from the vent production via microbial matter or decaying vent organisms. Vent and non-vent fauna were assigned to five feeding guilds: symbiont-containing fauna, bacterivores, detritivores, predator-scavengers, and suspension-feeders. Based on isotopic values of vent and non-vent fauna, as well as that of surficial sediments, it is inferred that the hydrothermal ecosystem in the Guaymas Basin is self-supported with high-energy efficiency and with low exporting capacity to the background deep-sea food web.

  1. Marine carbonate embayment system in an Eolian dune terrain, Permian Upper Minnelusa Formation, Rozet Area, Powder River Basin, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Achauer, C.W.

    1987-05-01

    The eolian origin for Minnelusa sandstones has been stressed in numerous published articles. However, the dolomites that are interbedded with the eolian sandstones have received little attention. Isopach mapping of one of the dolomite units (Dolomite I) reflects a marine embayment system whose individual embayments range from 1/2 to 1 mi in width and trend primarily in a northwest direction. Consistently the embayment dolomites pinch out against the flanks of reworked, low relief, broad, eolian dune ridges. So far, 108 mi/sup 2/ of the Dolomite I marine embayment system have been mapped, but the overall extent of the system is undoubtedly much greater. Dolomite I is rarely cored, but cores from stratigraphically higher embayment dolomites in the upper Minnelusa show that these dolomites display the following, shoaling-upward sequence: (1) subtidal, sparingly fossiliferous dolomite; (2) intertidal, algal-laminated or brecciated or mud-cracked dolomite; and (3) very thin, supratidal, nodular anhydrite. The embayments, therefore, became the sites of marine sabkhas located between eolian dunes. Two main conclusions emerge from this study: (1) the juxtaposition of eolian sandstones and marine dolomites in a tectonically stable area suggests that eustatic sea level changes and a very arid climate were responsible for the marked environmental and lithologic changes observed in the upper Minnelusa, and (2) arid, coastal, evaporitic sabkhas bordered by eolian dunes are known from a number of modern and ancient cases, but marine carbonate embayments and associated evaporitic sabkhas that penetrate deeply into eolian sandstone terrains are rare.

  2. High resolution ion microprobe investigation of the δ18O of carbonate cements (Jurassic, Paris Basin, France): New insights and pending questions

    Science.gov (United States)

    Vincent, Benoit; Brigaud, Benjamin; Emmanuel, Laurent; Loreau, Jean-Paul

    2017-04-01

    The scope of this work is to investigate, at a high resolution, the oxygen isotope composition (δ18Ocarb) of diagenetic products (synsedimentary and burial calcite cements) in shallow-marine carbonates. SIMS (Secondary Ion Mass Spectrometry) microprobe analyses were performed on thin sections from Oxfordian and Kimmeridgian Formations of the eastern Paris Basin and compared to data obtained on the same diagenetic products by conventional mass spectrometry (acid digestion). Hereby obtained, δ18O are similar, but the SIMS dataset displays a larger range of values. The isotopic zonation obtained by SIMS transects through sequences of cements filling pores, reveals an (expected) isotopic depletion from older stage synsedimentary calcites to younger stage blocky calcites and that follows the CL (cathodoluminescence) zonation. SIMS analyses however show that synsedimentary cements precipitated in intra-skeletal pores, have heavier δ18O than their inter-particle counterparts, with an offset of + 4‰V-PDB, despite similar petrographical characteristics. This difference is maintained in the δ18O of the first stages of blocky calcite cements, intra-skeletal blocky calcites showing heavier δ18O than the time equivalent and petrographically identical inter-particle calcites, with an offset of + 5‰V-PDB. These offsets are tentatively explained by the precipitation of cements under non-equilibrium conditions in intra-skeletal pores, where organic matter decay may have played a key role, acting notably on the pH. The occurrence of isolated micro-diagenetic environments, co-existing at the thin section scale, is tentatively proposed as an explanation to these small scale and high amplitude δ18O heterogeneities. These results may question the sampling strategy for future works. Microdrilling may miss the observed range of variation, but averaging the values may not necessarily lead to real misinterpretations if a critical selection of samples is performed, targeting

  3. Cyclostratigraphy of an orbitally-driven Tithonian-Valanginian carbonate ramp succession, Southern Mendoza, Argentina: Implications for the Jurassic-Cretaceous boundary in the Neuquén Basin

    Science.gov (United States)

    Kietzmann, Diego A.; Palma, Ricardo M.; Iglesia Llanos, Maria Paula

    2015-01-01

    Detailed sedimentological, sequence stratigraphical and cyclostratigraphical analyses have been made from four lower Tithonian-lower Valanginian sections of the Vaca Muerta Formation, exposed in the southern Mendoza area of the Neuquén Basin, Argentina. The Vaca Muerta Formation is characterized by decimetre-scale rhythmic alternations of marls, shales and limestones, and consists of five facies associations, which reflect different paleoenvironmental conditions: basin to restricted outer ramp, outer ramp, and middle ramp. Vertical organization within the Vaca Muerta Formation shows a well-ordered hierarchy of cycles, where elementary cycles, bundles and superbundles with frequencies within the Milankovitch band have been recognized. According to biostratigraphic data, elementary cycles have a periodicity of ~ 20 ky, which correlates with the precession cycle of Earth's axis. Spectral analysis based on series of cycle thickness allows us to identify frequencies of about 400 ky and 90-120 ky, which we interpret as the modulation of the precessional cycle by the Earth's orbital eccentricity. Cycles are probably driven by variations in carbonate exportation, as fluctuations in shallow-water carbonate production involve modifications in carbonate basinward exportation. Cyclostratigraphic data allowed us to build a floating orbital scale for the Tithonian-lower Valanginian interval in the Neuquén Basin. Correlation between studied sections allowed us to recognize a discontinuity between the Substeueroceras koeneni and Argentiniceras noduliferum ammonite zones in the Malargüe Anticline area. Orbital calibration of these sections is consistent with Riccardi's biostratigraphic scheme, wich place the Jurassic-Cretaceous boundary within the Substeueroceras koeneni ammonite Zone. On the other hand, the base of the Vaca Muerta Formation (Virgatosphinctes mendozanus ammonite Zone) would be probably placed in the base of the middle Tithonian rather than the lower Tithonian

  4. Geologic framework for the national assessment of carbon dioxide storage resources: Greater Green River Basin, Wyoming, Colorado, and Utah, and Wyoming-Idaho-Utah Thrust Belt: Chapter E in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Buursink, Marc L.; Slucher, Ernie R.; Brennan, Sean T.; Doolan, Colin A.; Drake II, Ronald M.; Merrill, Matthew D.; Warwick, Peter D.; Blondes, Madalyn S.; Freeman, P.A.; Cahan, Steven M.; DeVera, Christina A.; Lohr, Celeste D.

    2014-01-01

    The 2007 Energy Independence and Security Act (Public Law 110–140) directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used by the USGS for the national CO2 assessment follows up on previous USGS work. The methodology is non-economic and intended to be used at regional to subbasinal scales. This report identifies and contains geologic descriptions of 14 storage assessment units (SAUs) in Ordovician to Upper Cretaceous sedimentary rocks within the Greater Green River Basin (GGRB) of Wyoming, Colorado, and Utah, and eight SAUs in Ordovician to Upper Cretaceous sedimentary rocks within the Wyoming-Idaho-Utah Thrust Belt (WIUTB). The GGRB and WIUTB are contiguous with nearly identical geologic units; however, the GGRB is larger in size, whereas the WIUTB is more structurally complex. This report focuses on the characteristics, specified in the methodology, that influence the potential CO2 storage resource in the SAUs. Specific descriptions of the SAU boundaries, as well as their sealing and reservoir units, are included. Properties for each SAU, such as depth to top, gross thickness, porosity, permeability, groundwater quality, and structural reservoir traps, are typically provided to illustrate geologic factors critical to the assessment. This geologic information was employed, as specified in the USGS methodology, to calculate a probabilistic distribution of potential storage resources in each SAU. Figures in this report show SAU boundaries and cell maps of well penetrations through sealing units into the top of the storage formations. The cell maps show the number of penetrating wells within one square mile and are derived from interpretations of variably attributed well data and a digital compilation that is known not to include all drilling.

  5. Geologic framework for the national assessment of carbon dioxide storage resources: Hanna, Laramie, and Shirley Basins, Wyoming: Chapter C in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Merrill, Matthew D.; Covault, Jacob A.; Craddock, William H.; Slucher, Ernie R.; Warwick, Peter D.; Blondes, Madalyn S.; Gosai, Mayur A.; Freeman, P.A.; Cahan, Steven M.; Lohr, Celeste D.; Warwick, Peter D.; Corum, Margo D.

    2012-01-01

    The 2007 Energy Independence and Security Act (Public Law 110-140) directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used for the national CO2 assessment is non-economic and intended to be used at regional to subbasinal scales. This report identifies and contains geologic descriptions of twelve storage assessment units (SAUs) in six separate packages of sedimentary rock within the Hanna, Laramie, and Shirley Basins of Wyoming. It focuses on the particular characteristics, specified in the methodology, that influence the potential CO2 storage resource in those SAUs. Specific descriptions of SAU boundaries as well as their sealing and reservoir units are included. Properties for each SAU, such as depth to top, gross thickness, net porous thickness, porosity, permeability, groundwater quality, and structural reservoir traps are provided to illustrate geologic factors critical to the assessment. Although assessment results are not contained in this report, the geologic information included herein will be employed, as specified in the methodology, to calculate a statistical Monte Carlo-based distribution of potential storage space in the various SAUs. Figures in this report show SAU boundaries and cell maps of well penetrations through the sealing unit into the top of the storage formation. Cell maps show the number of penetrating wells within one square mile and are derived from interpretations of incompletely attributed well data in a digital compilation that is known not to include all drilling. The USGS does not expect to know the location of all wells and cannot guarantee the amount of drilling through specific formations in any given cell shown on cell maps.

  6. Hydrographic Areas Within the Basin and Range Carbonate-Rock Aquifer System, White Pine County, Nevada and Adjacent Areas in Nevada and Utah

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of sub delineations of the hydrographic area (HA) boundaries and polygons drawn at 1:1,000,000 scale for the Great Basin supplemented by...

  7. Irrigated Acreage Within the Basin and Range Carbonate-Rock Aquifer System, White Pine County, Nevada and Adjacent Areas in Nevada and Utah

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Accurate delineations of irrigated acreage are needed for the development of water-use estimates and in determining water-budget calculations for the Basin and Range...

  8. Determination of trapping pressure and temperature of petroleum inclusions using PVT simulation software - a case study of Lower Ordovician carbonates from the Lunnan Low Uplift, Tarim Basin

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D.H.; Xiao, X.M.; Mi, J.K.; Li, X.Q.; Shen, J.K.; Song, Z.G.; Peng, P.A. [Chinese Academy of Sciences, Guangzhou (China). Guangzhou Institute of Geochemistry, State Key Laboratory of Organic Geochemistry

    2003-01-01

    We report a case study carried out on Lower Ordovician reservoir carbonates of the Lunnan Low Uplift, Tarim Basin, to determine trapping pressures and temperatures of petroleum inclusions from the intersection of isochores of coeval petroleum and aqueous fluid inclusions using PVT SIM software. There are four types of petroleum inclusions from this sequence. Their trapping pressures and temperatures are: Type I 80-105 {sup o}C, 199-230 bar; Type II 135-145 {sup o}C, 235-250 bar; Type III 155-165 {sup o}C, 344-360 bar, and Type IV 220-252 {sup o}C, 345-390 bar, respectively, which are consistently higher than their homogenization temperature and saturation pressures by about 5-15 {sup o}C and 25-70 bar. To confirm the reliability of the PVT simulation approach, fluid inclusions were synthesized in calcite under controlled temperature and pressure conditions and studied using the same methods. The calculated trapping pressure and temperature of the synthetic petroleum inclusions closely match the actual pressure and temperature applied in the experiment. By reference to the burial and geothermal history of the Tarim host rocks, it was inferred that Types I, II and III petroleum inclusions represent fluids associated with three distinct phases of petroleum emplacement in the Lower Ordovician strata of this area, occurring during late Silurian to early Devonian, Cretaceous to early Tertiary, and late Tertiary, respectively. Type IV petroleum inclusions occur only in some fine calcite veins from few samples, and are believed to be related to an anomalous thermal event in this area. On the basis of the trapping pressures and trapping temperatures of the petroleum inclusions, three main phases of the petroleum-filling of the Lower Ordovician reservoirs can be delineated. Phase I and Phase III petroleum events were related to petroleum migration and accumulation from the Lunnan Low Uplift or nearby area. The petroleum of the phase II petroleum event appears to have

  9. Applying data mining methods to the assessment of soil contamination and carbon sequestration under Mediterranean Climate. The case study of Guadiamar basin (SW Spain).

    Science.gov (United States)

    Muñoz Vallés, Sara; Pino-Mejías, Rafael; Blanco-Velázquez, Francisco J.; Anaya-Romero, María

    2017-04-01

    In the present background of increasing access to vast datasets of soil and environmental records, the application of the newest analytical techniques and approaches for modelling offer excellent opportunities to define recommendations and simulate processes for land degradation and management. In this regard, data mining techniques have been successfully applied in different fields of environmental sciences, performing an innovative tool to explore relevant questions and providing valuable results and useful applications through an efficient management and analysis of large and heterogeneous datasets. Soil Organic matter, pH and trace elements in soil perform close relationships, with ability to alter each other and lead to emerging, synergic properties for soils. In addition, effects associated to climate and land use change promotes mechanisms of feedback that could amplify the negative effects of soil contamination on human health, biodiversity conservation and soil ecosystem services maintenance. The aim of this study was to build and compare several data mining models for the prediction of potential and interrelated functions of soil contamination and carbon sequestration by soils. In this context, under the framework of the EU RECARE project (Preventing and Remediating degradation of Soils in Europe through Land Care), the Guadiamar valley (SW Spain) is used as case study. The area was affected by around four hm3 of acid waters and two hm3 of mud rich in heavy metals, resulting from a mine spill, in 1998, where more than 4,600 ha of agricultural and pasture land were affected. The area was subjected to a large-scale phyto-management project, and consequently protected as "Green Corridor". In this study, twenty environmental variables were taken into account and several base models for supervised classification problems were selected, including linear and quadratic discriminant analysis, logistic regression, neural networks and support vector machines. A

  10. Methane and carbon dioxide adsorption capacity of bituminous coals from the Ostrava-Karvina Coal District, Upper Silesian Basin, Czech Republic

    Science.gov (United States)

    Weniger, P.; Busch, A.; Krooss, B. M.; Francu, J.; Francu, E.

    2009-04-01

    In the context of a joint Czech-German project, experimental and analytical methods are being applied to improve the understanding of compositional variation of coal-related gas in the SW part of the Upper Silesian Basin (Czech Republic). According to present understanding, the gas composition is controlled by generation (thermal vs. microbial), migration and adsorption/desorption processes. In particular the effects of the sorption processes on the chemical and isotopic composition of coal gases are only poorly explored. During the first stage of this project, the gas adsorption capacity has been determined for coal samples representing the paralic Ostrava Formation (Namurian A) and the limnic Karviná Formation (Namurian B-C). For this purpose, high pressure adsorption isotherms have been measured for methane and carbon dioxide on medium and low volatile bituminous coal (VRr 1.2-1.8%) from the production face of two collieries in the study area. Adsorption isotherms have been measured for pressures up to 25 MPa for CO2 and up to 17 MPa for methane at 20˚ C and 45˚ C. Isotherms were measured on dry, moisture-equilibrated and "as received" samples (moisture content: 0.5-1.7%, mineral-matter-free) using a manometric method. Sorption capacities for CH4 at 45˚ C ranged from 18 to 27 Std. cm3/g (0.7 to 1.1 mmol/g) coal, dry ash-free (daf), showing an increase of sorption capacity with increasing coal rank. For CO2, sorption capacities were generally higher than for methane, ranging from 35-40 Std. cm3/g (1.4-1.7 mmol/g) coal (daf). Equilibrium moisture contents, determined by a modified ASTM method, were significantly higher than the "as received" moisture. Sorption capacities measured on moisture-equilibrated samples were generally lower than those measured on dry or "as received" samples. Methane excess sorption isotherms show a type I Langmuir form and could be approximated using the Langmuir function. Excess sorption isotherms for CO2 show a decrease in

  11. C, O, and Sr isotopic variations in Neoproterozoic-Cambrian carbonate rocks from Sete Lagoas Formation (Bambuí Group, in the Southern São Francisco Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Cristian Guacaneme

    2017-08-01

    Full Text Available ABSTRACT: High-resolution chemostratigraphic data of carbonates from the Sete Lagoas Formation (Bambuí Group show large variations on the C, O, and Sr isotope compositions. Impure limestones at the base show primal δ13C values between -1.0 and 0‰, and δ18O values between -12.0 and -8.0‰. However, some dolostones demonstrate δ13C values varying from +2.8 to -6.8‰, highly radiogenic 87Sr/86Sr ratios (>0.7111, and low Sr concentrations (900 ppm. They are linked to depositional controls on the carbonate platform, such as fluvial and/or submarine water influx, in which carbonates deposited on the proximal sector exhibit significant Sr isotopic variations and those on the distal sector were not subject to such controls, resulting in very homogeneous Sr isotope profiles. However, 87Sr/86Sr ratios of the distal carbonates are less radiogenic than carbonates expected for late Ediacaran (~0.7085. This discrepancy suggests a restricted marine basin without Sr isotopic homogenization with contemporary oceans and, in this case, global correlations based on Sr isotope stratigraphy are not reliable.

  12. Triassic conodonts of the Slovenian Basin

    Directory of Open Access Journals (Sweden)

    Stanko Buser

    2007-06-01

    Full Text Available Slovenian Basin was formed during the Ladinian following disintegration of the Slovenian Carbonate Platform. It persisted continuously until the Late Cretaceous. Several conodont asscociations were recognized within the Triassic rocks of the Slovenian Basin. Stratigraphically significant species belong to the genera Budurovignathus, Epigondolella, Gladigondolella, Metapolygnathus, Misikella, Neogondolella, Nicoraella, Norigondolellaand Paragondolella.

  13. Consistent C3 plant habitat of hominins during 400-300 ka at the Longyadong Cave site (Luonan Basin, central China) revealed by stable carbon isotope analyses of loess deposits

    Science.gov (United States)

    Zhang, Hongyan; Lu, Huayu; Wang, Shejiang

    2017-04-01

    The proportions of woody and grassland taxa in terrestrial ecosystems played an important role in the origin and evolution of early Palaeolithic hominins. However the influence of ecosystem changes on hominin behavior and adaptations in Asia has not been studied in detail. Hominins have exploited the Luonan Basin in the Eastern Qinling Mountains, central China, since the early Paleolithic. Dated sites, consisting of alternating loess and soil deposits with in situ artefacts, are common in the region, and provide a detailed record of Early to Middle Pleistocene hominin environments. Here, we present the results of measurements of the stable carbon isotopic composition of soil organic matter (δ13C) in the loess-paleosol sequences from the Longyadong Cave site. Our analyses of δ13C show that for at least 400 ka the Longyadong Cave site and its surroundings were dominated by C3 woody plants, whereas the nearby Liuwan site was dominated by C4 and C3 mixed grassland or woody grassland vegetation. These findings demonstrate that between 400 and 300 ka in the Luonan Basin, hominins occupied a habitat consisting of a mosaic of grassland and woodland/forest. Although the vegetation of the region changed in response to the glacial-interglacial climatic cycles, patches of woody vegetation in landscapes such as at Longyadong Cave site persisted continuously. Such environments seem to be have been favored by hominins living in the Luonan Basin, possibly because they provided a diverse range of food resources during both glacial and interglacial intervals of the Middle Pleistocene, when most of northern China was experiencing an increasing trend of drying and cooling and steppe environments were expanding. Thus, the Luonan Basin would have served as a refugium for hominin occupation in China during the Middle Pleistocene.

  14. Groundwater model of the Great Basin carbonate and alluvial aquifer system version 3.0: Incorporating revisions in southwestern Utah and east central Nevada

    Science.gov (United States)

    Brooks, Lynette E.

    2017-12-01

    The groundwater model described in this report is a new version of previously published steady-state numerical groundwater flow models of the Great Basin carbonate and alluvial aquifer system, and was developed in conjunction with U.S. Geological Survey studies in Parowan, Pine, and Wah Wah Valleys, Utah. This version of the model is GBCAAS v. 3.0 and supersedes previous versions. The objectives of the model for Parowan Valley were to simulate revised conceptual estimates of recharge and discharge, to estimate simulated aquifer storage properties and the amount of reduction in storage as a result of historical groundwater withdrawals, and to assess reduction in groundwater withdrawals necessary to mitigate groundwater-level declines in the basin. The objectives of the model for the area near Pine and Wah Wah Valleys were to recalibrate the model using new observations of groundwater levels and evapotranspiration of groundwater; to provide new estimates of simulated recharge, hydraulic conductivity, and interbasin flow; and to simulate the effects of proposed groundwater withdrawals on the regional flow system. Meeting these objectives required the addition of 15 transient calibration stress periods and 14 projection stress periods, aquifer storage properties, historical withdrawals in Parowan Valley, and observations of water-level changes in Parowan Valley. Recharge in Parowan Valley and withdrawal from wells in Parowan Valley and two nearby wells in Cedar City Valley vary for each calibration stress period representing conditions from March 1940 to November 2013. Stresses, including recharge, are the same in each stress period as in the steady-state stress period for all areas outside of Parowan Valley. The model was calibrated to transient conditions only in Parowan Valley. Simulated storage properties outside of Parowan Valley were set the same as the Parowan Valley properties and are not considered calibrated. Model observations in GBCAAS v. 3.0 are

  15. Organic carbon at a remote site of the western Mediterranean Basin: sources and chemistry during the ChArMEx SOP2 field experiment

    Science.gov (United States)

    Michoud, Vincent; Sciare, Jean; Sauvage, Stéphane; Dusanter, Sébastien; Léonardis, Thierry; Gros, Valérie; Kalogridis, Cerise; Zannoni, Nora; Féron, Anaïs; Petit, Jean-Eudes; Crenn, Vincent; Baisnée, Dominique; Sarda-Estève, Roland; Bonnaire, Nicolas; Marchand, Nicolas; Langley DeWitt, H.; Pey, Jorge; Colomb, Aurélie; Gheusi, François; Szidat, Sonke; Stavroulas, Iasonas; Borbon, Agnès; Locoge, Nadine

    2017-07-01

    The ChArMEx (Chemistry and Aerosols Mediterranean Experiments) SOP2 (special observation period 2) field campaign took place from 15 July to 5 August 2013 in the western Mediterranean Basin at Ersa, a remote site in Cape Corse. During the campaign more than 80 volatile organic compounds (VOCs), including oxygenated species, were measured by different online and offline techniques. At the same time, an exhaustive description of the chemical composition of fine aerosols was performed with an aerosol chemical speciation monitor (ACSM). Low levels of anthropogenic VOCs (typically tens to hundreds of parts per trillion for individual species) and black carbon (0.1-0.9 µg m-3) were observed, while significant levels of biogenic species (peaking at the ppb level) were measured. Furthermore, secondary oxygenated VOCs (OVOCs) largely dominated the VOC speciation during the campaign, while organic matter (OM) dominated the aerosol chemical composition, representing 55 % of the total mass of non-refractory PM1 on average (average of 3.74 ± 1.80 µg m-3), followed by sulfate (27 %, 1.83 ± 1.06 µg m-3), ammonium (13 %, 0.90 ± 0.55 µg m-3) and nitrate (5 %, 0.31 ± 0.18 µg m-3). Positive matrix factorization (PMF) and concentration field (CF) analyses were performed on a database containing 42 VOCs (or grouped VOCs), including OVOCs, to identify the covariation factors of compounds that are representative of primary emissions or chemical transformation processes. A six-factor solution was found for the PMF analysis, including a primary and secondary biogenic factor correlated with temperature and exhibiting a clear diurnal profile. In addition, three anthropogenic factors characterized by compounds with various lifetimes and/or sources have been identified (long-lived, medium-lived and short-lived anthropogenic factors). The anthropogenic nature of these factors was confirmed by the CF analysis, which identified potential source areas known for intense anthropogenic

  16. Petrography, fluid inclusion and isotope studies in Ordovician carbonate reservoirs in the Shunnan area, Tarim basin, NW China: Implications for the nature and timing of silicification

    Science.gov (United States)

    Lu, Ziye; Chen, Honghan; Qing, Hairuo; Chi, Guoxiang; Chen, Qianglu; You, Donghua; Yin, Hang; Zhang, Siyang

    2017-08-01

    The Shunnan (SN) area, located in the center of the Tarim basin, NW China, is a gas field discovered in 2013, where the gas is hosted from deeply buried Ordovician carbonate reservoirs with burial depth > 6000 m and temperature > 190 °C. The most important reservoir rocks in the SN area are silicified limestones, which are characterized by multiple generations/types of authigenic quartz (Qz1-Qz2) and coarse calcite cement (CC1-CC3), in addition to other diagenetic phases. Qz1 is a replacement quartz postdating burial stylolites in both limestone and strongly silicified limestone, and Qz2 are equant and bladed quartz cements developed in fractures or vugs in strongly silicified limestone, also postdating burial stylolite. CC1 is a coarse calcite cement found in the vugs, which postdates medium crystalline dolomite and predates saddle dolomite. CC2 (including CC2a, CC2b and CC2c) is the calcite postdating Qz1 and burial stylolites. CC2a is found in fractures in limestone or slightly silicified limestone. CC2b, CC2c and CC3 are only identified in strongly silicified limestone. CC2b fills intercrystalline pores of Qz1, and CC2c fills fractures, predating Qz2. CC3 is precipitated in remaining space left by Qz2c in fractures or vugs. Sr isotopes were analyzed in CC2a and CC2c. CC2a has 87Sr/86Sr ratios of 0.70890-0.70917. CC2c is characterized with 87Sr/86Sr ratios of 0.70949-0.70972. Fluid inclusions were studied in all the quartz and coarse calcite cements. Fluid inclusions in CC2a are characterized by Th values of 118-131 °C and salinities of 22.9-25.2 wt% NaCl + CaCl2. Fluid inclusions from Qz2a, Qz2b, CC2b and CC2c have Th values of 143-166 °C and salinities of 14.7-23.7 wt% NaCl + CaCl2. Fluid inclusions in Qz2c are characterized by Th values of 125-132 °C and salinities of 24.8-26.8 wt% NaCl + CaCl2, and those in CC3 by Th values of 86-101 °C and salinities of 22.9-25.2 wt% NaCl + CaCl2. The Th drop, from Qz2a, Qz2b and CC2c to Qz2c and CC3, cannot be

  17. Organic carbon at a remote site of the western Mediterranean Basin: sources and chemistry during the ChArMEx SOP2 field experiment

    Directory of Open Access Journals (Sweden)

    V. Michoud

    2017-07-01

    Full Text Available The ChArMEx (Chemistry and Aerosols Mediterranean Experiments SOP2 (special observation period 2 field campaign took place from 15 July to 5 August 2013 in the western Mediterranean Basin at Ersa, a remote site in Cape Corse. During the campaign more than 80 volatile organic compounds (VOCs, including oxygenated species, were measured by different online and offline techniques. At the same time, an exhaustive description of the chemical composition of fine aerosols was performed with an aerosol chemical speciation monitor (ACSM. Low levels of anthropogenic VOCs (typically tens to hundreds of parts per trillion for individual species and black carbon (0.1–0.9 µg m−3 were observed, while significant levels of biogenic species (peaking at the ppb level were measured. Furthermore, secondary oxygenated VOCs (OVOCs largely dominated the VOC speciation during the campaign, while organic matter (OM dominated the aerosol chemical composition, representing 55 % of the total mass of non-refractory PM1 on average (average of 3.74 ± 1.80 µg m−3, followed by sulfate (27 %, 1.83 ± 1.06 µg m−3, ammonium (13 %, 0.90 ± 0.55 µg m−3 and nitrate (5 %, 0.31 ± 0.18 µg m−3. Positive matrix factorization (PMF and concentration field (CF analyses were performed on a database containing 42 VOCs (or grouped VOCs, including OVOCs, to identify the covariation factors of compounds that are representative of primary emissions or chemical transformation processes. A six-factor solution was found for the PMF analysis, including a primary and secondary biogenic factor correlated with temperature and exhibiting a clear diurnal profile. In addition, three anthropogenic factors characterized by compounds with various lifetimes and/or sources have been identified (long-lived, medium-lived and short-lived anthropogenic factors. The anthropogenic nature of these factors was confirmed by the CF analysis, which

  18. The Amazon Basin in transition

    Science.gov (United States)

    Eric A. Davidson; Alessandro C. de Araujo; Paulo Artaxo; Jennifer K. Balch; I. Foster Brown; Mercedes M.C. Bustamente; Michael T. Coe; Ruth S. DeFriess; Michael Keller; Marcos Longo; J. William Munger; Wilfrid Schroeder; Britaldo Soares-Filho; Carlos M. Souza, Jr.; Steven C. Wofsy

    2012-01-01

    Agricultural expansion and climate variability have become important agents of disturbance in the Amazon basin. Recent studies have demonstrated considerable resilience of Amazonian forests to moderate annual drought, but they also show that interactions between deforestation, fire and drought potentially lead to losses of carbon storage and changes in regional...

  19. Distribution of sulphur in the Albian coals of the Maestrazgo basin. Distribution del azufre en los carbones albienses de la cuenca del Maestrazgo

    Energy Technology Data Exchange (ETDEWEB)

    Querol, X.; Chinchon, J.S.; Lopez, A. (Inst. Geol. Jaume Almera, Barcelona (Spain))

    1989-01-01

    Important accumulations of coal took place in the proximal areas of a delta-estuary in the Maestrazgo Basin in Spain during the Middle Albian (Late Lower Cretaceous). Tectosedimentary control of this depositional system was carried out by distensive faults, creating a sedimentary space divided into four principal subbasins. Only two sub-basins (Calanda and Castellote), located in the northern sector of Maestrazgo Basin, contain workable coal deposits. These are dominantly subbituminous coals with high sulfur contents. In the present study inorganic sulfur bearing phases: (a) calcium, iron and magnesium sulfates; (b) iron sulfides (framboidal, euhedral fibrous and massive pyrite, and radial, anhedral and fibrous marcasite) and vertical distribution of sulfur in coal seams from Maestrazgo Basin coal are characterized. Some relations between the iron sulfide contents and the sedimentological features of interlayered sediments are shown; there is a clear tendency to increase iron sulfide content in the roofs of coal seams which are covered by marine influenced sediments. 22 refs., 2 figs., 7 plts., 2 tabs.

  20. Variation in tree mortality and regeneration affect forest carbon recovery following fuel treatments and wildfire in the Lake Tahoe Basin, California, USA.

    Science.gov (United States)

    Carlson, Chris H; Dobrowski, Solomon Z; Safford, Hugh D

    2012-06-28

    Forest fuel treatments have been proposed as tools to stabilize carbon stocks in fire-prone forests in the Western U.S.A. Although fuel treatments such as thinning and burning are known to immediately reduce forest carbon stocks, there are suggestions that these losses may be paid back over the long-term if treatments sufficiently reduce future wildfire severity, or prevent deforestation. Although fire severity and post-fire tree regeneration have been indicated as important influences on long-term carbon dynamics, it remains unclear how natural variability in these processes might affect the ability of fuel treatments to protect forest carbon resources. We surveyed a wildfire where fuel treatments were put in place before fire and estimated the short-term impact of treatment and wildfire on aboveground carbon stocks at our study site. We then used a common vegetation growth simulator in conjunction with sensitivity analysis techniques to assess how predicted timescales of carbon recovery after fire are sensitive to variation in rates of fire-related tree mortality, and post-fire tree regeneration. We found that fuel reduction treatments were successful at ameliorating fire severity at our study site by removing an estimated 36% of aboveground biomass. Treated and untreated stands stored similar amounts of carbon three years after wildfire, but differences in fire severity were such that untreated stands maintained only 7% of aboveground carbon as live trees, versus 51% in treated stands. Over the long-term, our simulations suggest that treated stands in our study area will recover baseline carbon storage 10-35 years more quickly than untreated stands. Our sensitivity analysis found that rates of fire-related tree mortality strongly influence estimates of post-fire carbon recovery. Rates of regeneration were less influential on recovery timing, except when fire severity was high. Our ability to predict the response of forest carbon resources to anthropogenic and

  1. Variation in tree mortality and regeneration affect forest carbon recovery following fuel treatments and wildfire in the Lake Tahoe Basin, California, USA

    Directory of Open Access Journals (Sweden)

    Carlson Chris H

    2012-06-01

    Full Text Available Abstract Background Forest fuel treatments have been proposed as tools to stabilize carbon stocks in fire-prone forests in the Western U.S.A. Although fuel treatments such as thinning and burning are known to immediately reduce forest carbon stocks, there are suggestions that these losses may be paid back over the long-term if treatments sufficiently reduce future wildfire severity, or prevent deforestation. Although fire severity and post-fire tree regeneration have been indicated as important influences on long-term carbon dynamics, it remains unclear how natural variability in these processes might affect the ability of fuel treatments to protect forest carbon resources. We surveyed a wildfire where fuel treatments were put in place before fire and estimated the short-term impact of treatment and wildfire on aboveground carbon stocks at our study site. We then used a common vegetation growth simulator in conjunction with sensitivity analysis techniques to assess how predicted timescales of carbon recovery after fire are sensitive to variation in rates of fire-related tree mortality, and post-fire tree regeneration. Results We found that fuel reduction treatments were successful at ameliorating fire severity at our study site by removing an estimated 36% of aboveground biomass. Treated and untreated stands stored similar amounts of carbon three years after wildfire, but differences in fire severity were such that untreated stands maintained only 7% of aboveground carbon as live trees, versus 51% in treated stands. Over the long-term, our simulations suggest that treated stands in our study area will recover baseline carbon storage 10–35 years more quickly than untreated stands. Our sensitivity analysis found that rates of fire-related tree mortality strongly influence estimates of post-fire carbon recovery. Rates of regeneration were less influential on recovery timing, except when fire severity was high. Conclusions Our ability to predict

  2. Extensive occurrence and genesis of authigenic carbonates from Krishna-Godavari offshore basin (Bay of Bengal): Possible influence of methane hydrates occurrences.

    Digital Repository Service at National Institute of Oceanography (India)

    Kocherla, M.; Pillai, S.; Patil, D.J.

    We report here the extensive occurrences of authigenic carbonate nodules/concretions from gas hydrate bearing sediments. Bulk mineralogical compositions by X-Ray diffractometry and EDS (Energy Dispersive Spectrum) analysis revealed...

  3. Scientific study of 13C/12C carbon and 18O/16O oxygen stable isotopes biological fractionation in grapes in the Black Sea, Don Basin and the Western Caspian regions

    Directory of Open Access Journals (Sweden)

    Kolesnov Alexander

    2017-01-01

    Full Text Available The report presents the results of a study of carbon and oxygen stable isotopes in carbohydrates and intracellular water of red and white grapes of 2016 wine-growing season in the Crimean peninsula areas, South-west coast of the Greater Caucasus, the Don basin and the Western Caspian region. The mass concentration of reducing sugars in the studied grape samples has been from 17.5 to 25.0 g/100 ml, titrated acids concentration (based on tartaric acid – from 6.0 to 9.1 g/l, the buffer capacity 34.1–63.2 mg-Eq/l. Red and white wine made from respective grapes contained from 0.5 to 3.6 g/l of residual sugar; from 11.1 to 14.5% ethanol by volume; buffer capacity was 35.2–52.6 mg-Eq/l. It has been found that the δ13CVPDB values for carbohydrates of red and white grape varieties as a result of biological fractionation of carbon isotopes in the agro-climatic conditions of plant growth for the studied geographical areas are ranging from − 26.74 to − 20.74‰ (the Crimean peninsula; from − 27.31 to − 21.58‰ (South West Coast of the Greater Caucasus, from − 27.33 to − 24.73‰ (Don Basin and from − 26.64 to − 23.17‰ (West Caspian. The δ13CVPDB values for ethanol of the red and white dry wines range from − 28.52 to − 24.26‰ (the Crimean peninsula; from − 29.23 to − 24.52‰ (South West Coast of the Greater Caucasus; from − 28.97 to − 26.22‰ (Don Basin; from − 29.14 to − 25.22‰ (Western Caspian. Compared with the surface water and groundwater (averages from δ18OVSMOW− 13.90 to − 6.38‰ and with precipitation (averages from δ18OVSMOW − 10.30 to − 9.04‰ the δ18OVSMOW values in intracellular water of grapes are the following: for the Crimean peninsula grapes, from 0.40 to 4.97‰; the South West Coast of the Greater Caucasus, from -2.11 to 6.29‰; the Don Basin, from − 2.21 to 6.26‰; the Western Caspian, from − 0.24 to 1.44‰. It has been noted that in conditions of

  4. Water circulation control on carbonate-{delta}{sup 18}O records in a low permeability clay formation and surrounding limestones: The Upper Dogger-Oxfordian sequence from the eastern Paris basin, France

    Energy Technology Data Exchange (ETDEWEB)

    Lavastre, Veronique, E-mail: veronique.lavastre@univ-st-etienne.fr [Universite de Lyon, Universite Jean Monnet, F-42023 Saint Etienne (France)] [CNRS, UMR 6524, LMV, F-42023 Saint Etienne (France)] [Laboratoire de Geochimie des Isotopes Stables, Institut de Physique du Globe de Paris and Universite Paris 7 - UMR CNRS 7154, 4, place Jussieu, 75252 Paris cedex 05 (France); Ader, Magali [Laboratoire de Geochimie des Isotopes Stables, Institut de Physique du Globe de Paris and Universite Paris 7 - UMR CNRS 7154, 4, place Jussieu, 75252 Paris cedex 05 (France); Buschaert, Stephane [Andra, Parc de la Croix Blanche, 7-8 rue Jean Monnet, 92 298 Chatenay-Malabry Cedex (France); Petit, Eddy; Javoy, Marc [Laboratoire de Geochimie des Isotopes Stables, Institut de Physique du Globe de Paris and Universite Paris 7 - UMR CNRS 7154, 4, place Jussieu, 75252 Paris cedex 05 (France)

    2011-05-15

    Research Highlights: > Up. Dog./Oxf. sequence is investigated for radioactive waste disposal feasibilities. > Marine carbonates suffered isotopic exchanges with meteoric water. > Modelling shows that very low W/R ratio can explain isotopic changes in clay layer. > Higher W/R ratio are needed to reach isotopic changes in carbonated layers. > Confirmed barrier property of clay layer was probably reached during early burial. - Abstract: Upper Dogger to Oxfordian Formations in the eastern part of the Paris basin (France) are currently being investigated by the French nuclear waste management agency (Andra), testing the feasibility of long-term deep nuclear waste disposal in the Callovo-Oxfordian claystones. Characterising the hydrogeological behaviour of the Callovo-Oxfordian claystones is, therefore, essential in evaluating its potential as a geological barrier. In order to evaluate and quantify water/rock interactions experienced over geological time by these Formations, bulk carbonate {delta}{sup 13}C and {delta}{sup 18}O were measured and calculations of water-rock ratios were used to explain carbonate-{delta}{sup 18}O changes. Meteoric porewater and a maximum temperature reached of about 40 deg. C were considered. The Jurassic marine carbonate {delta}{sup 13}C was preserved in the Callovo-Oxfordian claystones and in the overlying limestones (-0.28 per mille to 3.39 per mille/PDB), while the {delta}{sup 18}O values are lower by 0-5 per mille (-6.25 per mille to -1.32 per mille/PDB). Calculations show that Upper Dogger and Oxfordian Limestone {delta}{sup 18}O data: (i)have random-like distribution through theoretical {delta}{sup 18}O-W/R curves and (ii)suggest that water/rock ratios (0.08-0.4) needed to explain {delta}{sup 18}O changes are higher by a factor of about 2-20 compared to the present-day water/rock ratio. These features indicate advection in both aquifers. According to the history of the Paris basin, this hydrogeological behaviour could have been

  5. Basin analysis in the Southern Tethyan margin: Facies sequences, stratal pattern and subsidence history highlight extension-to-inversion processes in the Cretaceous Panormide carbonate platform (NW Sicily)

    Science.gov (United States)

    Basilone, Luca; Sulli, Attilio

    2018-01-01

    In the Mediterranean, the South-Tethys paleomargin experienced polyphased tectonic episodes and paleoenvironmental perturbations during Mesozoic time. The Cretaceous shallow-water carbonate successions of the Panormide platform, outcropping in the northern edge of the Palermo Mountains (NW Sicily), were studied by integrating facies and stratal pattern with backstripping analysis to recognize the tectonics vs. carbonate sedimentation interaction. The features of the Requienid limestone, including geometric configuration, facies sequence, lithological changes and significance of the top-unconformity, highlight that at the end of the Lower Cretaceous the carbonate platform was tectonically dismembered in various rotating fault-blocks. The variable trends of the subsidence curves testify to different responses, both uplift and downthrow, of various platform-blocks impacted by extensional tectonics. Physical stratigraphic and facies analysis of the Rudistid limestone highlight that during the Upper Cretaceous the previously carbonate platform faulted-blocks were subjected to vertical movements in the direction opposite to the displacement produced by the extensional tectonics, indicating a positive tectonic inversion. Comparisons with other sectors of the Southern Tethyan and Adria paleomargins indicate that during the Cretaceous these areas underwent the same extensional and compressional stages occurring in the Panormide carbonate platform, suggesting a regional scale significance, in time and kinematics, for these tectonic events.

  6. A tale of two stormwater basins: Nutrient cycling in grassed stormwater detention versus bioretention basins

    Science.gov (United States)

    McPhillips, L. E.; Walter, M. T.

    2016-12-01

    Nutrient cycling performance was compared in a grassed detention basin and a bioretention basin that was amended with compost, mulch, and diverse plantings. We monitored dissolved nutrients in basin inflows and outflows as well as emissions of greenhouse gases (GHGs) methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) from basin soils during 2014 and 2015. Though these basins are intended to improve storm runoff quality, the bioretention basin was a source of nitrate, soluble reactive phosphorus (SRP) and dissolved organic carbon (DOC). SRP and DOC leaching was driven by high P and C content of the bioretention soil media and nitrate leaching was driven by the low C:N of added compost. Emissions of N2O and CH4 were low from both basins, though there were periodically high N2O emission rates at both sites. CO2 emissions were greater from the bioretention basin, where soil C content was greater. Based on these results, bioretention basin design should minimize organic matter (OM) additions to soil media and choose OM with high C:N (>20) and low P content in order to minimize availability of excess nutrients for leaching or GHG production.

  7. Oil in the Malvinas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Galeazzi, J.S. [Astra, Anzoategui (Venezuela)

    1996-08-01

    The Malvinas Basin is petroliferous. The main source rocks are Late Jurassic and Early Cretaceous outer shelf to basinal shales known as the Pampa Rincon and Lower Inoceramus formations. Main reservoirs are fluvial and shallow-marine sandstones of the coeval Springhill Formation. On the western flank of the basin, 17 wells drilled the Cenozoic and Mesozoic column. Three of these wells discovered hydrocarbons within the Springhill Formation, and one discovered oil in Early Paleogene sandstones. Additionally, some wells recorded shows at different levels within the stratigraphic succession. A detailed overview of the drilled portion of the basin permitted the construction of a sequence stratigraphic framework, and yielded clues on a complex history of deformation. Interpretation of facies and stratal stacking and termination patterns determined that the main reservoir and source rocks were deposited in a ramp-style depositional setting. They represent the lower transgressive phase of a Late Jurassic to Early Cretaceous megasequence deposited during the early sag stage of the basin. Alternative reservoirs to the Springhill sandstones include early Paleogene glauconitic sandstones and carbonates, and Miocene deep-water turbidites. Structural trap styles include normal fault features of Jurassic to Early Cretaceous age, and compressional and inverted positive structures due to Neogene compression. Possible combination and stratigraphic traps include: little tested onlap pinchout of Late Jurassic to Early Cretaceous and Paleogene sandstones and untested erosionally truncated Paleogene sandstones; Early Paleogene carbonate buildups and Miocene deep-water turbidite mounds. The understanding of the geology of the western Malvinas Basin is the key to success of exploration in the huge frontier surrounding areas.

  8. Imagerie sismique d'un réservoir carbonaté : le dogger du Bassin parisien Seismic Imaging a Carbonate Reservoir: the Paris Basin Dogger

    Directory of Open Access Journals (Sweden)

    Mougenot D.

    2006-11-01

    ût important des acquisitions de surface en trois composantes, nous ne considérons pas cette méthode comme pertinente pour décrire le réservoir du Dogger. En définitive, la combinaison d'un échantillonnage spatial continu, comme celui obtenu en SD et d'une émission vibrosismique adaptée au filtrage terrain, comme celle utilisée en 2D-HR mais limitée à 100 Hz, apportera des informations nouvelles sur le réservoir mince et discontinu du Dogger que la simple corrélation des données de puits ne peut pas fournir. Ainsi, la géométrie du réservoir a pu être décrite avec précision (5 m de même que certaines hétérogénéités correspondant à des failles ou à des variations latérales d'impédance. D'autres paramètres importants pour la production, comme la répartition des drains R1 et R2 qui modifie peu les impédances acoustiques dans le réservoir, restent cependant inaccessibles à la sismique. Néanmoins, pour le prix d'un ou de quelques forages, une sismique 3D avec une émission et un traitement des données adaptés au Bassin parisien fournira une description suffisamment pertinente du réservoir pour pouvoir optimiser l'implantation de forages de délinéation ou de production, réduisant par là les coûts d'exploitation. (1 Dhyca: Direction des Hydrocarbures (Ministère de l'Industrie (2 CGG, EAP, Esso-REP, IFP, Total, Triton France. Within the context of measures taken by the Dhyca(1 to revitalize exploration in France, six industrial partners(2 joined forces (on the Dogger Project to develop an appropriate seismic acquisition, processing and interpretation methodology in order to improve the description of the main oil reservoir (Dogger in the Paris Basin by applying techniques already used on an industrial scale : vibroseis with a high frequency content (10-130 Hz, three-dimension or three-component reflection seismip, P and S emissions, sophisticated signal and static processing, amplitude preservation, careful well tying, stratigraphic

  9. A 560 yr summer temperature reconstruction for the Western Mediterranean basin based on stable carbon isotopes from Pinus nigra ssp. laricio (Corsica/France

    Directory of Open Access Journals (Sweden)

    J. Kuhlemann

    2012-10-01

    Full Text Available The Mediterranean is considered as an area which will be affected strongly by current climate change. However, temperature records for the past centuries which can contribute to a better understanding of future climate changes are still sparse for this region. Carbon isotope chronologies from tree-rings often mirror temperature history but their application as climate proxies is difficult due to the influence of the anthropogenic change in atmospheric CO2 on the carbon isotope fractionation during photosynthetic CO2 uptake. We tested the influence of different correction models accounting for plant response to increased atmospheric CO2 on four annually resolved long-term carbon isotope records (between 400 and 800 yr derived from Corsican pine trees (Pinus nigra ssp. laricio growing at ecologically varying mountain sites on the island of Corsica. The different correction factors have only a minor influence on the main climate signals and resulting temperature reconstructions. Carbon isotope series show strong correlations with summer temperature and precipitation. A summer temperature reconstruction (1448–2007 AD reveals that the Little Ice Age was characterised by low, but not extremely low temperatures on Corsica. Temperatures have been to modern temperatures at around 1500 AD. The reconstruction reveals warm summers during 1480–1520 and 1950–2007 AD and cool summers during 1580–1620 and 1820–1890 AD.

  10. Carbon and Nitrogen in the Lower Basin of the Paraíba do Sul River, Southeastern Brazil: Element fluxes and biogeochemical processes

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Martinelli

    2011-08-01

    Full Text Available The study was conducted in the lower basin of the Paraíba do Sul River (PSR, in which 57,000 km2 of the basin is located in the Brazilian states of São Paulo, Minas Gerais and Rio de Janeiro. We proposed to identify the main sources of C and N fluxes in the PSR waters, to evaluate biogeochemical processes in the watershed, and to estimate C and N riverine loads to the Atlantic Ocean in the context of the sugarcane plantation expansion for ethanol production. Riverine water samples were collected at seven stations along 12 months. Physicochemical and limnological parameters, as well as discharge, were measured together with organic and inorganic C and N species in the dissolved and suspended particulate material. C and N concentrations in bed fluvial sediments, and suspended particulate material were measured, and their elemental ([C:N]a and isotopic (δ13C compositions were compared with the [C:N]a and δ13C of the following sources: riparian soils, insular flooded soils, aquatic macrophytes, phytoplankton, pasture grass, sugarcane, sugarcane byproducts, and forest litterfall. Temporal patterns in the physicochemical and limnological environment were correlated to discharge. It also was observed that sugar cane production can increase riverine C and N fluxes. Riparian soils inputs were larger than insular soils, which was likely to act as a biogeochemical barrier. Effects of the macrophytes on riverine C and N were unclear, as well as urban sewage disposal effects. Although the PSR loads represented a very small percentage of the fluvial input to global biogeochemical cycles, we suggest that this and other medium sized watersheds in Eastern and Southeastern South America can be significant contributors to the continental biogeochemical riverine loads to the ocean, if their loads are considered together.

  11. San Mateo Creek Basin

    Science.gov (United States)

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  12. Dublin Basin

    OpenAIRE

    Somerville, I.D.; C. N. Waters

    2011-01-01

    The Carboniferous rocks of the Dublin Basin extend from the east coast of north Co. Dublin westwards to the River Shannon at Athlone and northwards to the Lower Palaeozoic rocks of the Longford-Down Massif (see Strogen et al. 1996, fig. 5; Sevastopulo & Wyse Jackson 2001, fig. 10.12; Fig. 21.1). They occur in counties Longford, Westmeath, Meath, north Co. Dublin, north Co. Offaly, north Co. Kildare and south Co. Dublin. Most of the rocks in the region belong to the Mississippia...

  13. Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California

    Science.gov (United States)

    Sickman, James O.; DiGiorgio, Carol L.; Davisson, M. Lee; Lucero, Delores M.; Bergamaschi, Brian A.

    2010-01-01

    We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was −254‰ in agricultural drains in the Sacramento–San Joaquin Delta, −218‰ in the San Joaquin River, −175‰ in the California State Water Project and −152‰ in the Sacramento River. The age of bulk DOC transiting the rivers of California’s Central Valley is the oldest reported for large rivers and suggests wide-spread loss of soil organic matter caused by agriculture and urbanization. Using DAX 8 adsorbent, we isolated and measured 14C concentrations in hydrophobic acid fractions (HPOA); river samples showed evidence of bomb-pulse carbon with average Δ14C of 91 and 76‰ for the San Joaquin and Sacramento Rivers, respectively, with older HPOA, −204‰, observed in agricultural drains. An operationally defined non-HPOA fraction of DOC was observed in the San Joaquin River with seasonally computed Δ14C values of between −275 and −687‰; the source of this aged material was hypothesized to be physically protected organic-matter in high clay-content soils and agrochemicals (i.e., radiocarbon-dead material) applied to farmlands. Mixing models suggest that the Sacramento River contributes about 50% of the DOC load in the California State Water Project, and agricultural drains contribute approximately one-third of the load. In contrast to studies showing stabilization of soil carbon pools within one or two decades following land conversion, sustained loss of soil organic matter, occurring many decades after the initial agricultural-land conversion, was observed in California’s Central Valley.

  14. Risk and geological uncertainties in carbonate reservoirs in Santos Basin; Incertezas geologicas e risco em reservatorios carbonaticos na Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Makoto; Cortez, Marcella M.M. [Queiroz Galvao Perfuracoes S.A., Rio de Janeiro, RJ (Brazil); Mendes, Marcos Huber

    2004-07-01

    The Lower Albian in the south part of Santos Basin is composed mainly of oolitic calcarenites and calcilutites organized in shoaling upward cycles. The calcarenites from the top of the sequence constitute a package of reservoir zones and sub-zones with regional distribution along which are located mature, producing and development phase oil fields. In this work the main factors with major impact in reserves estimation are interpreted and quantified in a probabilistic approach giving support for the development plan phase of a field of the carbonatic trend. The regional stratigraphic and structural interpretations provided information about extension, external geometry, and continuity of the reservoir zones for reserves risk computation. The porosity probability density functions were defined according to stratigraphic position, seismic reflection pattern of calcarenites and also information from the discovery and the appraisal wells. The Decision Tree methodology with Monte Carlo Simulation was used to better understand the impact of geological uncertainties in reserves computation and also as a first step for risk management. The Monte Carlo simulation allows the Multivariate Sensibility and Scenario Analysis, Probabilistic Technical and Economic Evaluation and Optimal Portfolio Stochastic Simulation. (author)

  15. Record of carbonate preservation and the Mid-Brunhes climatic shift from a seamount top with low sedimentation rates in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Sijinkumar, A.V.; Borole, D.V.; Gupta, S.M.; Mergulhao, L.P.; Mascarenhas-Pereira, M.B.L.; Ramaswamy, V.; Guptha, M.V.S.; Possnert, G.; Aldahan, A.; Khadge, N.H.; Sharma, R.

    the influence of earth’s orbital eccentricity cycles on the monsoonal SSTs for the last ~1.4 Ma in the CIB. Studies based on planktic foraminifera are lacking mainly due to non-availability of well preserved carbonate records. Since much of the sediments... of our record) in the CIB (Gupta 2009) at about ~250 ka BP (exactly conformable with our sediment record) implying an increase in monsoon-driven productivity (Fig. 5H). Increased amplitudes of high frequency (sub- orbital) 17, 15, and 13 ka cycles were...

  16. Seasonal plankton variability in Chilean Patagonia fjords: Carbon flow through the pelagic food web of Aysen Fjord and plankton dynamics in the Moraleda Channel basin

    Science.gov (United States)

    González, H. E.; Castro, L.; Daneri, G.; Iriarte, J. L.; Silva, N.; Vargas, C. A.; Giesecke, R.; Sánchez, N.

    2011-03-01

    Two research cruises ( CIMAR 13 Fiordos) were conducted in the N-S oriented macrobasin of the Moraleda Channel (42-47°S), which includes the E-W oriented Puyuhuapi Channel and Aysen Fjord, during two contrasting productive seasons: austral winter (27 July-7 August 2007) and spring (2-12 November 2007). These campaigns set out to assess the spatio-temporal variability, defined by the local topography along Moraleda Channel, in the biological, physical, and chemical oceanographic characteristics of different microbasins and to quantify the carbon budget of the pelagic trophic webs of Aysen Fjord. Seasonal carbon fluxes and fjord-system functioning vary widely in our study area. In terms of spatial topography, two constriction sills (Meninea and Elefantes) define three microbasins along Moraleda Channel, herein the (1) north (Guafo-Meninea), (2) central (Meninea-Elefantes), and (3) south (Elefantes-San Rafael Lagoon) microbasins. In winter, nutrient concentrations were high (i.e. nitrate range: 21-14 μM) and primary production was low (153-310 mgC m -2 d -1), suggesting that reduced light radiation depressed the plankton dynamics throughout Moraleda Channel. In spring, primary production followed a conspicuous N-S gradient, which was the highest (5167 mgC m -2 d -1) in the north microbasin and the lowest (742 mgC m -2 d -1) in the south microbasin. The seasonal pattern of the semi-enclosed Puyuhuapi Channel and Aysen Fjord, however, revealed no significant differences in primary production (˜800 mgC m -2 d -1), and vertical fluxes of particulate organic carbon were nearly twice as high in spring as in winter (266 vs. 168 mgC m -2 d -1). At the time-series station (St. 79), the lithogenic fraction dominated the total sedimented matter (seston). The role of euphausiids in the biological carbon pump of the Patagonian fjords was evident, given the predominance of zooplankton fecal material, mostly euphausiid fecal strings (46% of all fecal material), among the

  17. The Origin of Carbon-Bearing Volatiles in a Continental Hydrothermal System in the Great Basin: Water Chemistry and Isotope Characterizations

    Science.gov (United States)

    Fu, Qi; Socki, Richard A.; Niles, Paul B.; Romanek, Christopher; Datta, Saugata; Darnell, Mike

    2012-01-01

    Hydrothermal systems on Earth are active centers in the crust where organic molecules can be synthesized biotically or abiotically under a wide range of physical and chemical conditions [1-3]. Not only are volatile species (CO, CO2, H2, and hydrocarbons) a reflection of deep-seated hydrothermal alteration processes, but they also form an important component of biological systems. Studying carbon-bearing fluids from hydrothermal systems is of specific importance to understanding (bio-)geochemical processes within these systems. With recent detection of methane in the martian atmosphere [4-7] and the possibility of its hydrothermal origin [8, 9], understanding the formation mechanisms of methane may provide constraints on the history of the martian aqueous environments and climate.

  18. Geologic framework for the national assessment of carbon dioxide storage resources: Bighorn Basin, Wyoming and Montana: Chapter A in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Covault, Jacob A.; Buursink, Mark L.; Craddock, William H.; Merrill, Matthew D.; Blondes, Madalyn S.; Gosai, Mayur A.; Freeman, P.A.; Warwick, Peter D.; Corum, Margo D.

    2012-01-01

    The 2007 Energy Independence and Security Act (Public Law 110–140) directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used for the national CO2 assessment follows that of previous USGS work. The methodology is non-economic and intended to be used at regional to subbasinal scales.

  19. Hydrogeology of sedimentary basins

    Science.gov (United States)

    Kreitler, Charles W.

    1989-03-01

    Hydrogeologic environments in sedimentary basins are as variable as are the different types of basins. Important hydrologic characteristics can be used to distinguish the different types of basin: (1) the topographic setting as determined by the geologic and structural history of the basin; (2) permeability distribution within the basin; and (3) potential energy distributions and flow mechanisms. These parameters control residence times of waters, rates and directions of saline groundwater flow and the origin and chemical composition of the saline waters. The Gulf Coast and Palo Duro Basins, Texas, exemplify two end member types of sedimentary basins. The Gulf Coast Basin is a relatively young, Tertiary-age basin which is presently compacting; fluid movement is from the overpressured, undercompacted sediments up the structural dip or up fault zones into the hydrostatic section, natural fluid pressures are either hydrostatic or overpressured. The Palo Duro is an older, Paleozoic-age basin that has been tectonically uplifted. Fluid flow is gravity driven from topographically high recharge areas to discharge in topographically low areas. Fluid pressures are subhydrostatic. Fluids discharge more easily than they are recharged. Not all flow is derived by a simple recharge discharge model. Brines may flow from other basins into the Palo Duro Basin and waters may discharge from the Palo Duro Basin into other basins. Areal differences in the chemical composition of the basin brines may be the result of different origins.

  20. Geochemical characteristics and organic carbon sources within the ...

    Indian Academy of Sciences (India)

    Carbon (POC, DOC) and carbon isotopes (δ13C) within two headwater tributaries to the Xi River Basin, southwest China were analyzed to document the geochemical characteristics and sources of organic carbon (C) within basins characterized by a monsoonal climate and karst landforms. δ¹³CPOC value and C/N ratio ...

  1. Diffusion Properties of Carbonated Caprocks from the Paris Basin Propriétés diffusives de roches de couverture carbonatées du Bassin de Paris

    Directory of Open Access Journals (Sweden)

    Berne P.

    2009-11-01

    Full Text Available The efficiency of geological storage of CO2 lies in the confinement properties of the caprock. Among these properties, diffusive characteristics play an important, though sometimes underestimated, role. Although diffusion is a slow process, it can play a significant role in the long run. Besides, the desirable properties for a caprock – mainly high entry pressure and low permeability – are by no means contradictory with relatively high diffusion coefficients; the reason is that all these quantities do not depend on the same geometrical properties of the porous matrix (pore size in one case, tortuosity in the other. Within the framework of the Géocarbone-INTÉGRITÉ project, financed by the National Research Agency ANR from 2006 to 2008, the diffusion coefficients for water and bicarbonate ions have been measured in caprock samples from three levels (Comblanchien and Dalle Nacrée formations. These two species cover the main situations encountered in storage site conditions (neutral/charged species, interacting or not with the solid matrix. The model used for interpretation of the experiments is presented; this enables review of various quantities of interest: effective diffusion coefficient, pore diffusion coefficient, apparent diffusion coefficient, retardation factor. The pore self-diffusion coefficient for water was measured by two different techniques (Nuclear Magnetic Resonance and tritiated water 1H3HO tracing on two samples. The results are comparable: porosity about 6%, pore diffusion coefficient 2 × 10−10 m2/s, tortuosity about 10. The radioactive tracer method is then applied with tritiated water and carbon-14-tagged bicarbonate ions, H1CO-3, to samples from three depth levels. Reduction of accessible porosity is evidenced for bicarbonate ions, which is attributed to anionic exclusion. Interaction between bicarbonate ions and the solid matrix is also shown. This suggests that additional CO2storage capacity might be offered by

  2. JURASSIC PALEOGEOGRAPHY OF THE PIENINY AND OUTER CARPATHIAN BASINS

    Directory of Open Access Journals (Sweden)

    JAN GOLONKA

    2004-03-01

    Full Text Available The Jurassic history of the Pieniny/Outer Carpathian basins reflects the evolution of the Circum-Tethyan area, especially its Alpine Tethys part. The Alpine Tethys that is Ligurian, Penninic Oceans and Pieniny/Magura Basin constitute the extension of the Central Atlantic system. The synrift stage lasted in the Pieniny/Magura Basin from late Early Jurassic to Tithonian (the Magura Unit constitutes the southernmost part of the Outer Flysch Carpathians. The Pieniny rift opened during Pliensbachian – Aalenian. The central Atlantic and Alpine Tethys went into a drifting stage during the Middle Jurassic. The Late Jurassic (Oxfordian-Kimmeridgian history of the Pieniny/Magura Basin reflects strongest facial differentiation within sedimentary basin where mixed siliceous-carbonate sedimentation took place. Greatest deepening effect is indicated by widespread Oxfordian radiolarites, which occur in the all basinal successions, whereas the shallowest zone is completely devoid of siliceous intercalations at that time (sedimentation from Ammonitico Rosso facies up to coral reef limestone. The southern part of the North European Platform, north from the Pieniny/Magura realm, started to be rifted during Late Jurassic time and Silesian Basin in the Outer Western Carpathians and Sinaia Basin in the Eastern Carpathians, with black, mainly redeposited marls have been created. The outer sub-basins were differentiated during the latest (Hauterivian-Barremian phase of basinal development. The connection of Silesian Basin with Sinaia and Southern Carpathian Severin areas suggests the NW-SE direction of the basinal axis while the orientation of the Pieniny Klippen Belt/Magura Basin was SW-NE so, two Outer Carpathian perpendicular directions are possible within the basins. Major reorganization happened during the Tithonian-Berriasian time. It was reflected by both paleoceanographical and paleoclimatical changes. The Neo-Cimmerian tectonic events as well as main phase

  3. Microfacies and platform characteristic of the Ordovician in the northwestern Tarim Basin, NW China

    Science.gov (United States)

    Hu, Xiaolan; Li, Bo; Chen, Xiaozhi; Hong, Keyan; Jiang, Shenglin; Zhu, Liangliang; Wang, Di

    2017-06-01

    The Ordovician deposition is characterized by a thick carbonate in the Tarim Basin. In northwestern section of the basin, rocks are chiefly deposited in a carbonate ramp. Twelve microfacies have been distinguished on the basis of their depositional textures and petrographic analysis. Four depositional belts such as tidal flat, lagoon, shoal and open marine can be identified.

  4. Tectonic-depositional environment and proto-type basins evolution of the Late Ordovician in the Tarim Basin

    Science.gov (United States)

    Gao, Huahua; He, Dengfa; Tong, Xiaoguang; Wen, Zhixin; Wang, Zhaoming

    2017-04-01

    The tectonic-depositional environment of the Tarim Basin underwent a rapid and dramatic change in the Late Ordovician. The restoration of the proto-type basins has a great significance for the reveal of the basin-mountain coupling and basin fill process. Based on the newest data of drillings, seismic profiles and outcrops, with the analysis of sedimentary facies and the combination of basins and orogenic belts, this paper reconstructed the Late Ordovician tectonic-depositional environment of the Tarim Basin and established the models of basin-mountain couplings and basin fill processes, by employing the method of "point → line → face". In the Tumuxiuke Formation stage, the inundated platform-deep water basin sedimentary system was developed in the western part of the Tarim Basin and the Bachu-Tazhong area was denudated ; In the Lianglitage Formation stage, the open platform-deep water basin sedimentary system was developed and the Yudong-Tanggubasi area underwent the transition from the carbonate basin to the turbidite basin; in the Sangtamu Formation stage, the mixed shelf deposit- turbidite basin sedimentary system was developed and the under-filling deposit was only developed in the Kalpin; In the Tierekeawati Formation stage, the shore-shelf sedimentary system was developed. In the Tumuxiuke Formation- Sangtamu Formation stages, the turbidite basin sedimentary system was continually developed in the eastern part of the Tarim Basin; In the Tierekeawati Formation stage, the clastic shelf sedimentary system was developed in this area. The tectonic-depositional pattern of Tarim Basin in the Late Ordovician had the feature as the following: the platform-basin pattern differentiated from east to west was overlaid with the uplift-depression pattern differentiated from north to south. In the Tumuxiuke Formation stage, the unified platform in the west of the basin had broken down leading to the development of uplift-depression pattern differentiated from north to

  5. Mesozoic evolution of the Amu Darya basin

    Science.gov (United States)

    Brunet, Marie-Françoise; Ershov, Andrey; Korotaev, Maxim; Mordvintsev, Dmitriy; Barrier, Eric; Sidorova, Irina

    2014-05-01

    of the basin is occupied by the Pre-Kopet Dagh Cenozoic foreland basin NW oriented, possibly underlain by an earlier extensional trough. The main elements of the sedimentary pile, which can be partly observed in the South-Western Gissar are: Lower to Middle Jurassic continental to paralic clastic rocks; upper Middle to Upper Jurassic marine carbonate then thick Tithonian evaporite rocks, sealing the reservoirs in the Jurassic carbonates; continental Neocomian clastic rocks and red beds, Aptian to Paleogene marine carbonate and clastic rocks. To reconstruct the geodynamic evolution of the Amu Darya Basin, we analysed the subsidence by backstripping of some wells/pseudo-wells and of three cross-sections with some examples of thermal modelling on the periods of maturation of the potential source rocks. The crustal thinning events take place in the Permo-Triassic? (depending on the age of the rifts underlying the basin), in Early-Middle Jurassic and during the Early Cretaceous, resulting in increases of the tectonic subsidence rates.

  6. 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...

  7. Predicting the oceanic input of organic carbon by continental erosion

    OpenAIRE

    Ludwig, Wolfgang; Probst, Jean-Luc; Kempe, Stefan

    1996-01-01

    For a large set of major world rivers we established the empirical relations existing betwin the observed organic carbon fluxes and the climatic, biologic, and geomorphologic paterns characterizing the river basins.These characteristics where extracting from various ecological databases. The corresponding carbon fluxes were taken from the literature. Dissolved organic carbon fluxes are mainly related to drainage intensity, basin slope, and the amount of carbon stored in soils. Particulate or...

  8. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico-stratigraphic hierarchy and cycle stacking facies distribution, and interwell-scale heterogeneity: Grayburg Formation, New Mexico. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barnaby, R.J.; Ward, W.B.; Jennings, J.W. Jr.

    1997-06-01

    The Grayburg Formation (middle Guadalupian) is a major producing interval in the Permian Basin and has yielded more than 2.5 billion barrels of oil in West Texas. Grayburg reservoirs have produced, on average, less than 30 percent of their original oil in place and are undergoing secondary and tertiary recovery. Efficient design of such enhanced recovery programs dictates improved geological models to better understand and predict reservoir heterogeneity imposed by depositional and diagenetic controls. The Grayburg records mixed carbonate-siliciclastic sedimentation on shallow-water platforms that rimmed the Delaware and Midland Basins. Grayburg outcrops in the Guadalupe and Brokeoff Mountains region on the northwest margin of the Delaware Basin present an opportunity to construct a detailed, three-dimensional image of the stratigraphic and facies architecture. This model can be applied towards improved description and characterization of heterogeneity in analogous Grayburg reservoirs. Four orders of stratigraphic hierarchy are recognized in the Grayburg Formation. The Grayburg represents a long-term composite sequence composed of four high-frequency sequences (HFS 1-4). Each HFS contains several composite cycles comprising two or more cycles that define intermediate-scale transgressive-regressive successions. Cycles are the smallest scale upward-shoaling vertical facies successions that can be recognized and correlated across various facies tracts. Cycles thus form the basis for establishing the detailed chronostratigraphic correlations needed to delineate facies heterogeneity.

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

    Science.gov (United States)

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

    2017-12-01

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

  10. Confining Properties of Carbonated Dogger Caprocks (Parisian Basin for CO2 Storage Purpose Propriétés de confinement des couvertures du Dogger carbonaté (Bassin de Paris dans l’optique du stockage de CO2

    Directory of Open Access Journals (Sweden)

    Carles P.

    2010-05-01

    Full Text Available The Géocarbone-Intégrité project, funded by ANR (Agence Nationale de la Recherche from 2006 to 2008, has the overall objective of gaining knowledge and technology to predict storage integrity and safety for long term geological CO2 sequestration. The aim of this study (Sect. 1 and 2 of the project is to evaluate the sealing capacities of the carbonated Dogger caprocks located on top of the reservoirs where CO2 could be injected for storage purposes in the Parisian Basin. A petrographic analysis is done on 3 different cores from geological formations of the “Comblanchien and Dalle Nacrée” tight carbonates facies. At the same time, a petrophysical study of these facies is performed. Porosity, pore size distribution and permeability are determined using special devices adapted to low permeability and tight rocks ( Le projet Géocarbone-Intégrité, financé par l’Agence Nationale de la Recherche (ANR de 2006 à 2008, vise à développer les connaissances et les techniques nécessaires à la prévision de l’efficacité et la sécurité du confinement sur le long terme des stockages géologiques de CO2. La première tâche a été de caractériser à l’échelle pétrographique, les faciès carbonatés du sommet du Dogger appartenant aux formations des Calcaires du Comblanchien et de la Dalle Nacrée, situées immédiatement au-dessus des niveaux réservoirs retenus comme potentiels sites de stockage. Une étude pétrophysique précise des faciès de couvertures potentielles est réalisée. La porosité, la distribution de taille de pores et la perméabilité sont déterminées en utilisant des méthodes adaptées à des milieux très peu perméables (< 10 microDarcy. Les perméabilités sont mesurées à l’azote, à l’hélium et à la saumure sous pression de confinement avec la méthode stationnaire et la méthode transitoire. Les porosités sont faibles et varient de 2 à 9 % suivant le faciès, et les perméabilités en

  11. Great Basin insect outbreaks

    Science.gov (United States)

    Barbara Bentz; Diane Alston; Ted Evans

    2008-01-01

    Outbreaks of native and exotic insects are important drivers of ecosystem dynamics in the Great Basin. The following provides an overview of range, forest, ornamental, and agricultural insect outbreaks occurring in the Great Basin and the associated management issues and research needs.

  12. An Overview of Geologic Carbon Sequestration Potential in California

    Energy Technology Data Exchange (ETDEWEB)

    Cameron Downey; John Clinkenbeard

    2005-10-01

    As part of the West Coast Regional Carbon Sequestration Partnership (WESTCARB), the California Geological Survey (CGS) conducted an assessment of geologic carbon sequestration potential in California. An inventory of sedimentary basins was screened for preliminary suitability for carbon sequestration. Criteria included porous and permeable strata, seals, and depth sufficient for critical state carbon dioxide (CO{sub 2}) injection. Of 104 basins inventoried, 27 met the criteria for further assessment. Petrophysical and fluid data from oil and gas reservoirs was used to characterize both saline aquifers and hydrocarbon reservoirs. Where available, well log or geophysical information was used to prepare basin-wide maps showing depth-to-basement and gross sand distribution. California's Cenozoic marine basins were determined to possess the most potential for geologic sequestration. These basins contain thick sedimentary sections, multiple saline aquifers and oil and gas reservoirs, widespread shale seals, and significant petrophysical data from oil and gas operations. Potential sequestration areas include the San Joaquin, Sacramento, Ventura, Los Angeles, and Eel River basins, followed by the smaller Salinas, La Honda, Cuyama, Livermore, Orinda, and Sonoma marine basins. California's terrestrial basins are generally too shallow for carbon sequestration. However, the Salton Trough and several smaller basins may offer opportunities for localized carbon sequestration.

  13. Selection and Characterization of Geological Sites able to Host a Pilot-Scale CO2 Storage in the Paris Basin (GéoCarbone-PICOREF Choix et caractérisation de sites géologiques propices à l’installation d’un pilote pour le stockage de CO2 dans le bassin de Paris (GéoCarbone-PICOREF

    Directory of Open Access Journals (Sweden)

    Brosse É.

    2010-06-01

    Full Text Available The objective of the GéoCarbone-PICOREF project was to select and characterize geological sites where CO2 storage in permeable reservoir could be tested at the pilot scale. Both options of storage in deep saline aquifer and in depleted hydrocarbon field were considered. The typical size envisioned for the pilot was 100 kt CO2 per year. GéoCarbone-PICOREF initially focused on a “Regional Domain”, ca. 200 × 150 km, in the Paris Basin. It was attractive for the following reasons: detailed geological data is available, due to 50 years of petroleum exploration; basin-scale deep saline aquifers are present, with a preliminary estimate of storage capacity which is at the Gt CO2 level, namely the carbonate Oolithe Blanche Formation, of Middle Jurassic age, generally located between 1500 and 1800 m depths in the studied area, and several sandstone formations of Triassic age, located between 2000 and 3000 m; several depleted oil fields exist: although offering storage capacities at a much lower level, they do represent very well constrained geological environments, with proven sealing properties; several sources of pure CO2 were identified in the area, at a flow rate compatible with the pilot size, that would avoid capture costs. 750 km of seismic lines were reprocessed and organized in six sections fitted on well logs. This first dataset provided improved representations of: the gross features of the considered aquifers in the Regional Domain; the structural scheme; lateral continuity of the sealing cap rocks. An inventory of the environmental characteristics was also made, including human occupancy, protected areas, water resource, natural hazards, potential conflicts of use with other resources of the subsurface, etc. From all these criteria, a more restricted geographical domain named the “Sector”, ca. 70 × 70 km, was chosen, the most appropriate for further selection of storage site(s. The geological characterization of the Sector has

  14. K Basin safety analysis

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-16

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

  15. Geometry and Dynamics of the Mesopotamian Foreland Basin

    Science.gov (United States)

    Pirouz, M.; Avouac, J. P.; Gualandi, A.; Hassanzadeh, J.; Sternai, P.

    2016-12-01

    We have constrained the geometry of the Zagros foreland basin along the entire northern edge of the Arabian plate using subsurface data from Iran, Iraq and Syria. We use the Oligo-Miocene marine Asmari Formation and its equivalents in the region to reconstruct high resolution foreland basin geometry. This extensive carbonate platform limestone unit separates pre-collisional passive margin marine sediments from the Cenozoic foreland deposits dominated by continental sources; and therefore it can be used as a measure of post-collisional deflection. The 3D reconstructed Asmari Formation shows along-strike thickness variations of the foreland basin deposits from 1 to 6 km. The deepest part of the foreland basin coincides with the Dezful embayment in Iran, and its depth decreases on both sides. In principle the basin geometry should reflect the loading resulted from overthrusting in the Zagros fold-thrust belt, the sediment fill and dynamic stresses due to lithospheric and upper mantle deformation. To estimate these various sources of loads we analyze the basin geometry in combination with gravity, free air anomaly, and Moho depths determined from seismological observations. Our analysis suggests in particular that redistribution of surface load by surface processes is a primary controlling factor of the basin geometry. The wavelength of a foreland basin may bear little information on the elastic flexural rigidity of the lithosphere.

  16. Wada basin boundaries and basin cells

    NARCIS (Netherlands)

    Nusse, H.E.; Yorke, J.A.

    1996-01-01

    In dynamical systems examples are common in which two or more attractors coexist, and in such cases the basin boundary is nonempty. We consider a two-dimensional diffeomorphism F (that is, F is an invertible map and both F and its inverse are differentiable with continuous derivatives), which has at

  17. South American sedimentary basins

    Energy Technology Data Exchange (ETDEWEB)

    Urien, C.M.

    1984-04-01

    More than 64 sedimentary basins have been identified on the South American continent. According to their regional structural character and tectonic setting, they are classified in 4 super groups. About 20 interior or intracratonic basins occur on South American cratons (Guayanas, Brazilian, and Patagonian). In most cases, their sedimentary fill is Paleozoic or early Mesozoic. Rift or transverse grabens resulting from incipient sea floor spreading extend towards the continental margin. Seventeen basins are located along the Atlantic stable margin, and consist primarily of half grabens with downfaulted seaward blocks. These rifts (or pull-apart basins) were separated as results of the migration of the African and American continental blocks. Therefore the sedimentation is chiefly Cretaceous and Tertiary. On the western edge of South American cratons, almost 20 basins of downwarped blocks extend from Orinoco down to the Malvinas plateau in a relatively uninterrupted chain of retroarc basins, bordered by the Andean orogen. They lie on a flexured Precambrian and Paleozoic basement, and are highly deformed in the west (Subandean belt) due to the action of compressional forces caused by the tectonic influence of the Mesozoic Andean batholith. Westward, the Pacific margin is bordered by 27 foreland and forearc basins, which alternate from north to south on an unstable or quasistable margin, fringed by a trench and slope complex where the ocean crust is subducted beneath the continental plate.

  18. River basin administration

    Science.gov (United States)

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

  19. Watershed Planning Basins

    Data.gov (United States)

    Vermont Center for Geographic Information — The Watershed Planning Basin layer is part of a larger dataset contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

  20. BASINS Framework and Features

    Science.gov (United States)

    BASINS enables users to efficiently access nationwide environmental databases and local user-specified datasets, apply assessment and planning tools, and run a variety of proven nonpoint loading and water quality models within a single GIS format.

  1. California Air Basins

    Data.gov (United States)

    California Department of Resources — Air ResourcesCalifornia Air Resources BoardThe following datasets are from the California Air Resources Board: * arb_california_airbasins - California Air BasinsThe...

  2. Post-breakup Basin Evolution along the South-Atlantic Margins

    Science.gov (United States)

    Strozyk, Frank; Back, Stefan; Kukla, Peter

    2014-05-01

    The post-breakup tectono-stratigraphic evolution of large offshore basins along the South American and African continental margins record strongly varying post-rift sedimentary successions. The northernmost segment of the South Atlantic rift and salt basins is characterized by a pronounced asymmetry, with the Brazilian margin comprising narrower and deeper rift basins with less salt in comparison to the Congo-Gabon conjugate margin. Another important observation is that multiple phases of uplift and subsidence are recorded after the break-up of the southern South Atlantic on both sides of the Florianopolis-Walvis Ridge volcanic complex, features that are regarded as atypical when compared to published examples of other post-breakup margin successions. A regional comparison based on tectonic-stratigraphic analysis of selected seismic transects between the large basins offshore southern Brazil (Espirito Santo Basin, Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Lower Congo Basin, Kwanza Basin, Namibe Basin, Walvis Basin) provides a comprehensive basin-to-basin documentation of the key geological parameters controlling ocean and continental margin development. This comparison includes the margin configuration, subsidence development through time, sediment influx and storage patterns, type of basin fill (e.g. salt vs. non-salt systems; carbonate-rich vs. clastics-dominated systems) and finally major tectonic and magmatic events. Data from the salt basins indicate that salt-related tectonic deformation is amongst the prime controls for the non-uniform post-rift margin development. The diversity in the stratigraphic architecture of the conjugate margins offshore southern Brazil, Namibia and Angola reflects variations in the interplay of a number of controlling factors, of which the most important are (a) the structural configuration of each margin segment at the time of break-up, (b) the post break-up subsidence history of the respective margin segment

  3. Sedimentology and sequence stratigraphy of a Tithonian-Valanginian carbonate ramp (Vaca Muerta Formation): A misunderstood exceptional source rock in the Southern Mendoza area of the Neuquén Basin, Argentina

    Science.gov (United States)

    Kietzmann, Diego A.; Palma, Ricardo M.; Riccardi, Alberto C.; Martín-Chivelet, Javier; López-Gómez, José

    2014-04-01

    The Vaca Muerta Formation (early Tithonian-early Valanginian) is a rhythmic succession of marls and limestones, cropping out in the Neuquén Basin, west-central Argentina. This lithostratigraphic unit was traditionally interpreted as basinal to slope deposits. Detailed facies analysis allows to differentiate seven facies associations, representing basinal to middle ramp facies of a homoclinal ramp system prograding westward from the eastern margin, and slope facies attributed to a distally steepened ramp system that progrades eastward from the Andean volcanic arc in the west. Two sequence hierarchies are recognized: five third order depositional sequences, and fifteen fourth order high-frequency sequences. Fluctuations in organic matter content within the Vaca Muerta Formation suggest relationship with depositional sequences, finding the highest values associated with transgressive system tracts. This work represents an important advance in the understanding of the sedimentary and stratigraphic evolution of this exceptional unconventional reservoir. Our sequence stratigraphic approach contributes to the understanding of the relationship between organic matter, facies, and sea-level changes.

  4. Basin-scale simulation of current and potential climate changed hydrologic conditions in the Lake Michigan Basin, United States

    Science.gov (United States)

    Christiansen, Daniel E.; Walker, John F.; Hunt, Randall J.

    2014-01-01

    The Great Lakes Restoration Initiative (GLRI) is the largest public investment in the Great Lakes in two decades. A task force of 11 Federal agencies developed an action plan to implement the initiative. The U.S. Department of the Interior was one of the 11 agencies that entered into an interagency agreement with the U.S. Environmental Protection Agency as part of the GLRI to complete scientific projects throughout the Great Lakes basin. The U.S. Geological Survey, a bureau within the Department of the Interior, is involved in the GLRI to provide scientific support to management decisions as well as measure progress of the Great Lakes basin restoration efforts. This report presents basin-scale simulated current and forecast climatic and hydrologic conditions in the Lake Michigan Basin. The forecasts were obtained by constructing and calibrating a Precipitation-Runoff Modeling System (PRMS) model of the Lake Michigan Basin; the PRMS model was calibrated using the parameter estimation and uncertainty analysis (PEST) software suite. The calibrated model was used to evaluate potential responses to climate change by using four simulated carbon emission scenarios from eight general circulation models released by the World Climate Research Programme’s Coupled Model Intercomparison Project phase 3. Statistically downscaled datasets of these scenarios were used to project hydrologic response for the Lake Michigan Basin. In general, most of the observation sites in the Lake Michigan Basin indicated slight increases in annual streamflow in response to future climate change scenarios. Monthly streamflows indicated a general shift from the current (2014) winter-storage/snowmelt-pulse system to a system with a more equally distributed hydrograph throughout the year. Simulated soil moisture within the basin illustrates that conditions within the basin are also expected to change on a monthly timescale. One effect of increasing air temperature as a result of the changing

  5. Alboran Basin, southern Spain - Part I: Geomorphology

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, A. [Secretaria General de Pesca Maritima, Corazon de Maria, 8, 28002 Madrid (Spain); Ballesteros, M.; Rivera, J.; Acosta, J. [Instituto Espanol de Oceanografia, Corazon de Maria, 8, 28002 Madrid (Spain); Montoya, I. [Universidad Juan Carlos I, Campus de Mostoles, Madrid (Spain); Uchupi, E. [Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States)

    2008-01-15

    Bathymetric, 3D relief and shaded relief maps created from multibeam echo-sounding data image the morphology of the Alboran Basin, a structural low along the east-west-trending Eurasian-African plates boundary. Topographic features in the basin are the consequence of volcanism associated with Miocene rifting, rift and post-rift sedimentation, and recent faulting resulting from the convergence of the African-Eurasian plates. Pleistiocene glacially induced regressions/transgressions when the sea level dropped to about 150 m below its present level gas seeps and bottom currents. Recent faulting and the Pleistocene transgressions/regressions led to mass-wasting, formation of turbidity currents and canyon erosion on the basin's slopes. Recent fault traces at the base of the northern basin slope have also served as passageways for thermogenic methane, the oxidation of which by bacteria led to the formation of carbonate mounds along the fault intercepts on the sea floor. Expulsion of thermogenic or biogenic gas has led to the formation of pockmarks; erosion by bottom currents has resulted in the formation of moats around seamounts and erosion of the seafloor of the Alboran Ridge and kept the southern edge of the 36 10'N high sediment free. (author)

  6. Restoring the Mississippi River Basin from the Catchment to the Coast Defines Science and Policy Issues of Ecosystem Services Associated with Alluvial and Coastal Deltaic Floodplains: Soil Conservation, Nutrient Reduction, Carbon Sequestration, and Flood Control

    Science.gov (United States)

    Twilley, R.

    2014-12-01

    Large river systems are major economic engines that provide national economic wealth in transporting commerce and providing extensive agriculture production, and their coastal deltas are sites of significant ports, energy resources and fisheries. These coupled natural and social systems from the catchment to the coast depend on how national policies manage the river basins that they depend. The fundamental principle of the Mississippi River Basin, as in all basins, is to capitalize on the ability of fertile soil that moves from erosional regions of a large watershed, through downstream regions of the catchment where sediment transport and storage builds extensive floodplains, to the coastal region of deposition where deltas capture sediment and nutrients before exported to the oceans. The fate of soil, and the ability of that soil to do work, supports the goods and services along its path from the catchment to the coast in all large river basin and delta systems. Sediment is the commodity of all large river basin systems that together with the seasonal pulse of floods across the interior of continents provide access to the sea forming the assets that civilization and economic engines have tapped to build national and global wealth. Coastal landscapes represent some of the most altered ecosystems worldwide and often integrate the effects of processes over their entire catchment, requiring systemic solutions to achieve restoration goals from alluvial floodplains upstream to coastal deltaic floodplains downstream. The urgent need for wetland rehabilitation at landscape scales has been initiated through major floodplain reclamation and hydrologic diversions to reconnect the river with wetland processes. But the constraints of sediment delivery and nutrient enrichment represent some critical conflicts in earth surface processes that limit the ability to design 'self sustaining' public work projects; particularly with the challenges of accelerated sea level rise. Only

  7. Climate Change Impacts on the Congo Basin Region

    NARCIS (Netherlands)

    Ludwig, F.; Franssen, W.; Jans, W.W.P.; Kruijt, B.; Supit, I.

    2012-01-01

    This report presents analyses of climate change impacts in the Congo Basin on water for agriculture and hydropower, forest ecosystem functioning and carbon storage and impacts of climate variability and change on future economic development. To quantify the impacts of future climate we developed a

  8. Organic Matter of the Mulhouse Basin, France: A synthesis

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hofmann, P.; Huc, A.Y.; Carpentier, B.; Schaeffer, P.; Albrecht, P.; Keely, B.J.; Maxwell, J.R.; Leeuw, J.W. de; Leythaeuser, D.

    1993-01-01

    The lower Oligocene evaporite sequence of the Mulhouse Basin (France) contains organic matter-rich marl deposits. These marls display an overall cyclic variation of sedimentation rate, organic carbon content, hydrogen index and selected molecular parameters over a 30 m thick stratigraphic interval.

  9. Identifying Oil Exploration Leads using Intergrated Remote Sensing and Seismic Data Analysis, Lake Sakakawea, Fort Berthold Indian Reservation, Willistion Basin

    Energy Technology Data Exchange (ETDEWEB)

    Scott R. Reeves; Randal L. Billingsley

    2004-02-26

    The Fort Berthold Indian Reservation, inhabited by the Arikara, Mandan and Hidatsa Tribes (now united to form the Three Affiliated Tribes) covers a total area of 1530 mi{sup 2} (980,000 acres). The Reservation is located approximately 15 miles east of the depocenter of the Williston basin, and to the southeast of a major structural feature and petroleum producing province, the Nesson anticline. Several published studies document the widespread existence of mature source rocks, favorable reservoir/caprock combinations, and production throughout the Reservation and surrounding areas indicating high potential for undiscovered oil and gas resources. This technical assessment was performed to better define the oil exploration opportunity, and stimulate exploration and development activities for the benefit of the Tribes. The need for this assessment is underscored by the fact that, despite its considerable potential, there is currently no meaningful production on the Reservation, and only 2% of it is currently leased. Of particular interest (and the focus of this study) is the area under the Lake Sakakawea (formed as result of the Garrison Dam). This 'reservoir taking' area, which has never been drilled, encompasses an area of 150,000 acres, and represents the largest contiguous acreage block under control of the Tribes. Furthermore, these lands are Tribal (non-allotted), hence leasing requirements are relatively simple. The opportunity for exploration success insofar as identifying potential leads under the lake is high. According to the Bureau of Land Management, there have been 591 tests for oil and gas on or immediately adjacent to the Reservation, resulting in a total of 392 producing wells and 179 plugged and abandoned wells, for a success ratio of 69%. Based on statistical probability alone, the opportunity for success is high.

  10. Strontium isotope stratigraphy of the Pelotas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Zerfass, Geise de Santana dos Anjos, E-mail: geise.zerfass@petrobras.com.br [Petroleo Brasileiro S.A. (PETROBRAS/CENPES/PDGEO/BPA), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento Leopoldo Americo Miguez de Mello; Chemale Junior, Farid, E-mail: fchemale@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Instituto de Geociencias; Moura, Candido Augusto Veloso, E-mail: candido@ufpa.br [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Geociencias. Dept. de Geoquimica e Petrologia; Costa, Karen Badaraco, E-mail: karen.costa@usp.br [Instituto Oceanografico, Sao Paulo, SP (Brazil); Kawashita, Koji, E-mail: koji@usp.br [Unversidade de Sao Paulo (USP), SP (Brazil). Centro de Pesquisas Geocronologicas

    2014-07-01

    Strontium isotope data were obtained from foraminifera shells of the Pelotas Basin Tertiary deposits to facilitate the refinement of the chronostratigraphic framework of this section. This represents the first approach to the acquisition of numerical ages for these strata. Strontium isotope stratigraphy allowed the identification of eight depositional hiatuses in the Eocene-Pliocene section, here classified as disconformities and a condensed section. The reconnaissance of depositional gaps based on confident age assignments represents an important advance considering the remarkably low chronostratigraphic resolution in the Cenozoic section of the Pelotas Basin. The recognition of hiatuses that match hiatuses is based on biostratigraphic data, as well as on global events. Furthermore, a substantial increase in the sedimentation rate of the upper Miocene section was identified. Paleotemperature and productivity trends were identified based on oxygen and carbon isotope data from the Oligocene-Miocene section, which are coherent with worldwide events, indicating the environmental conditions during sedimentation. (author)

  11. Palaeoenvironmental changes across the Danian–Selandian boundary in the North Sea Basin

    DEFF Research Database (Denmark)

    Clemmensen, Anne; Thomsen, Erik

    2005-01-01

    The Danian–Selandian boundary (not, vert, similar60 Ma) marks the cessation of 40 million years of carbonate deposition in the North Sea Basin and a shift to siliciclastic deposition. On the basis of variations in lithology, benthic and planktonic foraminifera and calcareous nannofossils in three...... groups the benthic assemblages into four biofacies, which correspond fairly closely to lithological units. Correlation of the Storebælt records with marine palaeorecords from the Danish Basin and the North Sea Basin indicate that the transformation of the North Sea from a carbonate to a siliciclastic...... basin occurred in four steps separated by relatively long, stable periods. The most important external factors involved in the change are, firstly, a drop in the relative sea-level during the late Danian leading to the disappearance of bryozoans from the North Sea Basin and to non-deposition and erosion...

  12. Hydrogeology and water quality of the Chakari Basin, Afghanistan

    Science.gov (United States)

    Mack, Thomas J.; Chornack, Michael P.; Flanagan, Sarah M.; Chalmers, Ann T.

    2014-01-01

    The hydrogeology and water quality of the Chakari Basin, a 391-square-kilometer (km2) watershed near Kabul, Afghanistan, was assessed by the U.S. Geological Survey and the Afghanistan Geological Survey to provide an understanding of the water resources in an area of Afghanistan with considerable copper and other mineral resources. Water quality, chemical, and isotopic samples were collected at eight wells, four springs, one kareze, and the Chakari River in a basin-fill aquifer in the Chakari Basin by the Afghanistan Geological Survey. Results of water-quality analyses indicate that some water samples in the basin had concentrations of chemical constituents that exceeded World Health Organization guidelines for nitrate, sodium, and dissolved solids and some of the samples also had elevated concentrations of trace elements, such as copper, selenium, strontium, uranium, and zinc. Chemical and isotopic analyses, including for tritium, chlorofluorocarbons, and carbon-14, indicate that most wells contain water with a mixture of ages from young (years to decades) to old (several thousand years). Three wells contained groundwater that had modeled ages ranging from 7,200 to 7,900 years old. Recharge from precipitation directly on the basin-fill aquifer, which covers an area of about 150 km2, is likely to be very low (7 × 10-5 meters per day) or near zero. Most recharge to this aquifer is likely from rain and snowmelt on upland areas and seepage losses and infiltration of water from streams crossing the basin-fill aquifer. It is likely that the older water in the basin-fill aquifer is groundwater that has travelled along long and (or) slow flow paths through the fractured bedrock mountains surrounding the basin. The saturated basin-fill sediments in most areas of the basin are probably about 20 meters thick and may be about 30 to 60 meters thick in most areas near the center of the Chakari Basin. The combination of low recharge and little storage indicates that groundwater

  13. Modifed Great Basin Extent (Buffered)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Two different great basin perimeter files were intersected and dissolved using ArcGIS 10.2.2 to create the outer perimeter of the great basin for use modeling...

  14. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-05-26

    The principal research effort for Phase 1 (Concept Development) of the project has been data compilation; determination of the tectonic, depositional, burial, and thermal maturation histories of the North Louisiana Salt Basin; basin modeling (geohistory, thermal maturation, hydrocarbon expulsion); petroleum system identification; comparative basin evaluation; and resource assessment. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, and regional cross sections have been prepared. Structure, isopach and formation lithology maps have been constructed, and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs include Upper Jurassic and Cretaceous fluvial-deltaic sandstone facies; shoreline, marine bar and shallow shelf sandstone facies; and carbonate shoal, shelf and reef facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary. Hydrocarbon

  15. Vast Peatlands Found in the Congo Basin

    Science.gov (United States)

    Fatoyinbo, Lola

    2017-01-01

    Southeast Asias share of Earths tropical peatlands was previously put at 561, but the largest of the tropics peatland complexes might in fact lie elsewhere. On page 86, Dargie et al. combine satellite data with extensive field measurements of peat depth, carbon concentration and radiocarbon dating to produce a map of potential peat extent and carbon stocks in the Cuvette Centrale depression of the central Congo Basin. The authors propose that the Cuvette Centrale represents the worlds largest tropical peatland complex, covering 145,500 square kilometres and possibly storing about 30 petagrams of carbon (1 Pg is 1015 grams) the equivalent of 20 years of current US carbon emissions from fossil fuels. Tropical peatlands have garnered increasing attention in recent years owing to their crucial role as terrestrial organic carbon reserves and the implications of peatland loss for climate change. Thick peat soils (ranging from 30 cm to up to 30 m)3 form in areas where water-logged soils create anoxic conditions that prevent organic materials such as dead leaves and wood from fully decomposing. The largest areas of peat are in temperate regions, but large areas of forested peatlands are also found in the tropics.

  16. Pacific basin energy

    Science.gov (United States)

    Testimony is presented concerning pending legislation which provides for the assessment and development of the potential for renewable energy sources in the U.S. insular areas, including the trust territories. Options for self-sufficiency throughout the Pacific basin are considered in light of rapidly escalating fuel costs.

  17. Single-basined choice

    NARCIS (Netherlands)

    Bossert, W.; Peters, H.J.M.

    2013-01-01

    Single-basined preferences generalize single-dipped preferences by allowing for multiple worst elements. These preferences have played an important role in areas such as voting, strategy-proofness and matching problems. We examine the notion of single-basinedness in a choice-theoretic setting. In

  18. Basin Hopping Graph

    DEFF Research Database (Denmark)

    Kucharik, Marcel; Hofacker, Ivo; Stadler, Peter

    2014-01-01

    basins when the direct transitions between them are “energetically favorable”. Edge weights endcode the corresponding saddle heights and thus measure the difficulties of these favorable transitions. BHGs can be approximated accurately and efficiently for RNA molecules well beyond the length range...

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

    Science.gov (United States)

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

    2017-04-01

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

  20. Seismic-geometric facies model of lacustrine carbonates of Morro do Chaves Formation, Sergipe-Alagoas Basin; Modelagem sismica-geometrica de facies dos carbonatos lacustres da Formacao Morro do Chaves, Bacia de Sergipe-Alagoas

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Eliseu Massaaki [Internacional America Latina PETROBRAS Colombia (Colombia). E e P. UN-COL. Gerencia de Ativos Offshore], e-mail: eliseuk@petrobras.com.br

    2010-05-15

    Sergipe-Alagoas Basin, to the seismic facies of a high-resolution seismic section (out thrust-1) from the same outcrop This model was based on the interaction of three models: the Integration Facies Model; Stratigraphic- Structural Facies Model and Velocity Facies Model. The first relates the gamma-rays, sonic velocity, porosity and geometry information with the kinds of facies associations. The second is the result of the integration of the first model with the outcrop 3-D Laser-scanner topographic image and the structural geometric observations. The last is the representation of the substitution of the facies associations of the second model for their respective sonic velocities. This last model was the input parameter to the 2-D acoustic model, which produced a synthetic seismic section of the outcrop of a similar standard to the high-resolution section of out thrust-1. The out thrust-1 high-resolution seismic section interpretation, based on the Seismic-Geometric Facies Model, demonstrated that the facies associations found in the shallow drill hole S-217 and well FU-107, both 50m from the seismic line, correlate in the same seismic-stratigraphic level. More importantly, the geometries of the seismic facies found in the stratigraphic and structural positions were consistent with those observed in the outcrop geological structural analysis. This evidence indicates that the seismic model of the coquinas outcrop, Morro do Chaves Formation, may be used as an analogue model in hydrocarbon exploration and production activities, particularly in the coquinas facies reservoirs of the Lagoa Feia Formation, Campos Basin. (author)

  1. 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.

  2. Formation stage and controlling factors of the paleo-uplifts in the Tarim Basin: A further discussion

    OpenAIRE

    Yuan Neng; Guanghui Wu; Shaoying Huang; Xing Zhang; Shujuan Cao

    2016-01-01

    Various types of paleo-uplifts with different characteristics are developed in the Tarim Basin. Previously, there were multiple opinions on the pale-uplifts origins and structural evolution, so the oil and gas exploration ideas and deployment in the Tarim Basin were not developed smoothly. In this paper, regional seismic interpretation and structural analysis were carried out on the deep marine carbonate rocks in this basin based on the new seismic and drilling data. Then combined with the st...

  3. Bransfield Basin and Cordilleran Orogenesis

    Science.gov (United States)

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

    2003-12-01

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

  4. Geothermal fluid genesis in the Great Basin

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, T.; Buchanan, P.K.

    1990-01-01

    Early theories concerning geothermal recharge in the Great Basin implied recharge was by recent precipitation. Physical, chemical, and isotopic differences between thermal and non-thermal fluids and global paleoclimatic indicators suggest that recharge occurred during the late Pleistocene. Polar region isotopic studies demonstrate that a depletion in stable light-isotopes of precipitation existed during the late Pleistocene due to the colder, wetter climate. Isotopic analysis of calcite veins and packrat midden megafossils confirm the depletion event occurred in the Great Basin. Isotopic analysis of non-thermal springs is utilized as a proxy for local recent precipitation. Contoured plots of deuterium concentrations from non-thermal and thermal water show a regional, systematic variation. Subtracting contoured plots of non-thermal water from plots of thermal water reveals that thermal waters on a regional scale are generally isotopically more depleted. Isolated areas where thermal water is more enriched than non-thermal water correspond to locations of pluvial Lakes Lahontan and Bonneville, suggesting isotopically enriched lake water contributed to fluid recharge. These anomalous waters also contain high concentrations of sodium chloride, boron, and other dissolved species suggestive of evaporative enrichment. Carbon-age date and isotopic data from Great Basin thermal waters correlate with the polar paleoclimate studies. Recharge occurred along range bounding faults. 151 refs., 62 figs., 15 tabs.

  5. Frontier petroleum basins of Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Keith, J.F. Jr.; Perez, V.E.

    1989-03-01

    The frontier basins of Colombia with hydrocarbon potential are numerous, have varying geological histories, and are in different stages of exploration development. In this paper, sedimentary or structural basins are classified as frontier petroleum basins if commercial discoveries of hydrocarbons are lacking, if the basin has not attained a high degree of exploration development, or if a new play concept has been perceived or developed for a portion of a mature exploration basin. Using these criteria for classification, the authors discuss the Cauca-Patia Choco-Pacifico, and Lower Magdalena basin complexes; the Cordillera Oriental foreland basin; and the Cesar-Rancheria, Sabana, and Amazonas basins. A comprehensive geological and structural setting of each of these frontier basins will be presented. The depositional and tectonic evolution of the basins will be highlighted, and the play concepts for each will be inventoried, catalogued, and categorized as to whether they are theoretical or established. The discussion of the available plays in each of these basins will include the main play concept elements of reservoirs traps, seals, source rocks, maturation, and timing. When detailed data permit, the reservoir and trap geometry will be presented.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-05-15

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

  7. Zinc and Its Isotopes in the Loire River Basin, France

    Science.gov (United States)

    Millot, R.; Desaulty, A. M.; Bourrain, X.

    2014-12-01

    The contribution of human activities such as industries, agriculture and domestic inputs, becomes more and more significant in the chemical composition of the dissolved load of rivers. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river basins include anthropogenic disturbances. The Loire River in central France is approximately 1010 km long and drains an area of 117,800 km2. In the upper basin, the bedrock is old plutonic rock overlain by much younger volcanic rocks. The intermediate basin includes three major tributaries flowing into the Loire River from the left bank: the Cher, the Indre and the Vienne rivers; the main stream flows westward and its valley stretches toward the Atlantic Ocean. Here, the Loire River drains the sedimentary series of the Paris Basin, mainly carbonate deposits. The lower Loire basin drains pre-Mesozoic basement of the Armorican Massif and its overlying Mesozoic to Cenozoic sedimentary deposits. The Loire River is one of the main European riverine inputs to the Atlantic ocean. Here we are reporting concentration and isotope data for Zn in river waters and suspended sediments from the Loire River Basin. In addition, we also report concentration and isotope data for the different industrial sources within the Loire Basin, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany. These organisms are known to be natural accumulators of metal pollutants. Zinc isotopic compositions are rather homogeneous in river waters with δ66Zn values ranging from 0.21 to 0.39‰. This range of variation is very different from anthropogenic signature (industrial and/or agriculture release) that displays δ66Zn values between 0.02 to 0.14‰. This result is in agreement with a geogenic origin and the low Zn concentrations in the Loire River Basin (from 0.8 to 6 µg/L).

  8. Petrophysical Properties of the Middle Jurassic Carbonates in the PICOREF Sector (South Champagne, Paris Basin, France Propriétés pétrophysiques du Dogger carbonaté dans le Secteur PICOREF (Sud Champagne, bassin de Paris, France

    Directory of Open Access Journals (Sweden)

    Delmas J.

    2010-05-01

    Full Text Available This article, carried out as part of the PICOREF Project for the CO2 storage in the aquifers of the Paris Basin, presents an important petrophysical database from the numerous petroleum wells drilled in the PICOREF Sector (south-eastern part of the Paris Basin between 1953 and 2001. These core data concern the three saline carbonated aquifers of the Middle Jurassic: the Oolithe Blanche and the Comblanchien formations, Upper Bathonian age, and the Dalle Nacrée formation, Lower Callovian age, that would be used for the CO2 sequestration. Located at –1230 to –1750 m sub sea in the studied sector, these carbonate reservoirs which cumulative thickness is about 150 m, outcrop in the Burgundy region, at about 80 km south-eastern the Sector where they are exploited in several quarries. The analysis of the 6800 routine measurements (porosity and permeability gathered for this study allowed to improve the knowledge of the petrophysical properties. Special measurements (mercury injection tests allowed to characterize the porous medium. Cet article, réalisé dans le cadre du Projet PICOREF(1 pour le stockage de CO2 dans les aquifères du bassin parisien, présente une importante base de données pétrophysiques issues des nombreux puits pétroliers forés dans le Secteur PICOREF (sud-est du bassin parisien entre 1953 et 2001. Ces données concernent les trois aquifères salins du Dogger carbonaté susceptibles d’être utilisés pour séquestrer du CO2 : l’Oolithe Blanche et le Comblanchien, d’âge Bathonien supérieur, ainsi que la Dalle Nacrée d’âge Callovien inférieur. Recoupés à des altitudes de – 1230 à – 1750 m/mer dans le secteur étudié, ces réservoirs carbonatés, dont l’épaisseur cumulée est de 150 m environ, affleurent en Bourgogne, à 80 km au sud-est du « Secteur », où ils sont exploités dans plusieurs carrières. L’analyse des 6800 mesures classiques (porosité et perméabilité rassemblées ici a permis d

  9. Diagenetic evolution of Cenozoic sandstones, Gulf of Mexico sedimentary basin

    Science.gov (United States)

    Land, Lynton S.; Milliken, Kitty Lou; McBride, Earle F.

    1987-03-01

    The Gulf of Mexico sedimentary basin is a natural laboratory for the study of on-going diagenetic and incipient metamorphic processes. Sediments and rocks of Eocene through Pleistocene age have been studied from the surface to depths in excess of 6 km. Sediments heated to temperatures above 100°C have been massively transformed by mechanical compaction, cementation, and extensive alteration of detrital components. Grain dissolution, albitization, and clay-mineral transformations have reduced an initially complex detrital assemblage to quartz, albite, illite and minor carbonate at temperatures above 100°C. Volumetrically significant diagenetic processes observed in the basin include cementation by quartz, carbonate and kaolinite, grain dissolution (affecting mainly potassium feldspar, heavy minerals, and plagioclase), albitization, and the transformation of smectite to illite. Excepting carbonate cementation which shows essentially no depth-related variation, these processes occur shallower in older units, most likely in response to variations in the geothermal gradient, which is higher in the older Cenozoic depocenters. The magnitudes of the principal diagenetic processes all support the view that basinal diagenesis operates as an open system on a very large scale. Strontium isotopic data for authigenic carbonates document vertical transport on the scale of kilometers. The extent to which metamorphic processes below 6 km have effected the course of diagenesis in shallower rocks is still unproven, but current data suggest that burial diagenesis must be studied in such a context.

  10. Post-breakup Basin Evolution along the South-Atlantic Margins in Brazil and Angola/Namibia

    Science.gov (United States)

    Kukla, P. A.; Strozyk, F.; Back, S.

    2013-12-01

    The post-breakup tectono-stratigraphic evolution of large offshore basins along the South American and African continental margins record strongly varying post-rift sedimentary successions. The northernmost segment of the South Atlantic rift and salt basins is characterized by a pronounced asymmetry, with the Brazilian margin comprising narrower and deeper rift basins with less salt in comparison to the Congo-Gabon conjugate margin. Another important observation is that multiple phases of uplift and subsidence are recorded after the break-up of the southern South Atlantic on both sides of the Florianopolis-Walvis Ridge volcanic complex, features that are regarded as atypical when compared to published examples of other post-breakup margin successions. A regional comparison based on tectonic-stratigraphic analysis of selected seismic transects between the large basins offshore southern Brazil (Espirito Santo Basin, Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Lower Congo Basin, Kwanza Basin, Namibe Basin, Walvis Basin) provides a comprehensive basin-to-basin documentation of the key geological parameters controlling ocean and continental margin development. This comparison includes the margin configuration, subsidence development through time, sediment influx and storage patterns, type of basin fill (e.g. salt vs. non-salt systems; carbonate-rich vs. clastics-dominated systems) and finally major tectonic and magmatic events. Data from the salt basins indicate that salt-related tectonic deformation is amongst the prime controls for the non-uniform post-rift margin development. The diversity in the stratigraphic architecture of the conjugate margins offshore southern Brazil, Namibia and Angola reflects variations in the interplay of a number of controlling factors, of which the most important are (a) the structural configuration of each margin segment at the time of break-up, (b) the post break-up subsidence history of the respective margin segment

  11. Integrated Hydrographical Basin Management. Study Case – Crasna River Basin

    Science.gov (United States)

    Visescu, Mircea; Beilicci, Erika; Beilicci, Robert

    2017-10-01

    Hydrographical basins are important from hydrological, economic and ecological points of view. They receive and channel the runoff from rainfall and snowmelt which, when adequate managed, can provide fresh water necessary for water supply, irrigation, food industry, animal husbandry, hydrotechnical arrangements and recreation. Hydrographical basin planning and management follows the efficient use of available water resources in order to satisfy environmental, economic and social necessities and constraints. This can be facilitated by a decision support system that links hydrological, meteorological, engineering, water quality, agriculture, environmental, and other information in an integrated framework. In the last few decades different modelling tools for resolving problems regarding water quantity and quality were developed, respectively water resources management. Watershed models have been developed to the understanding of water cycle and pollution dynamics, and used to evaluate the impacts of hydrotechnical arrangements and land use management options on water quantity, quality, mitigation measures and possible global changes. Models have been used for planning monitoring network and to develop plans for intervention in case of hydrological disasters: floods, flash floods, drought and pollution. MIKE HYDRO Basin is a multi-purpose, map-centric decision support tool for integrated hydrographical basin analysis, planning and management. MIKE HYDRO Basin is designed for analyzing water sharing issues at international, national and local hydrographical basin level. MIKE HYDRO Basin uses a simplified mathematical representation of the hydrographical basin including the configuration of river and reservoir systems, catchment hydrology and existing and potential water user schemes with their various demands including a rigorous irrigation scheme module. This paper analyzes the importance and principles of integrated hydrographical basin management and develop a case

  12. An introduction to Precambrian basins: their characteristics and genesis

    Science.gov (United States)

    Eriksson, P. G.; Martins-Neto, M. A.; Nelson, D. R.; Aspler, L. B.; Chiarenzelli, J. R.; Catuneanu, O.; Sarkar, S.; Altermann, W.; Rautenbach, C. J. de W.

    2001-06-01

    Precambrian and younger basins reflect the interaction of sediment supply and subsidence; the latter is generally ascribed to tectonic, magmatic and related thermal processes. The interplay of supply and subsidence is further modified by eustasy and palaeoclimate. Problems and enigmas inherent in analysis of Precambrian basin-fills include: a spectrum of ideas on the maximum age of Phanerozoic-style plate tectonics in the rock record; Archaean heat flow up to two to three times present values; changes in magmatism over time (including global magmatic events); the evolution of atmospheric composition and of life and their influence on weathering, erosion and sediment supply rates; degree of preservation, deformation and metamorphism, and preservational bias (especially of intracratonic basins which would lack evidence for early plate tectonics); a limited rock record; poor age constraints, inherent errors in geochronological techniques and difficulty in dating the time of deposition of sedimentary rocks. Major influences on Precambrian basin formation are assumed to include magmatism, plate tectonics, eustasy and palaeoclimate, all of which interacted. Models for greenstone belt evolution include plate tectonic intra-oceanic generation, plume-generated oceanic plateau, and global catastrophic magmatic events that may have been transitional to a plate tectonic regime over several hundred million years. The latter transition may have included the onset of the supercontinent cycle. Insignificant preservation of Precambrian ocean floor makes evaluation of these models problematic. Eustasy was intrinsically related to continental crustal growth rates, continental freeboard and the hypsometric curves of emerging cratons. Possible maximum crustal growth rates near the Archaean-Proterozoic boundary led to globally elevated sea levels, and the formation of enormous carbonate-banded iron formation platforms where cyanobacterial mats, which produced oxygen, flourished. The

  13. Los Angeles Summer Midday Particulate Carbon: Primary and Secondary Aerosol

    OpenAIRE

    Turpin, Barbara J.; Huntzicker, James J.; Larson, Susan M.; Cass, Glen R.

    1991-01-01

    Aerosol sampling during photochemically active times across the Los Angeles Basin has provided evidence of secondary formation of organic aerosol from gas-phase precursors at midday. Ambient organic carbon/elemental carbon ratios exceeded the estimated ratio of organic carbon/elemental carbon in primary source emissions on most sampling days at all sites. The concentration of secondary organic aerosol was calculated by using ambient data and estimates of the organic ca...

  14. Geologic evolution and hydrocarbon prospects in the Chotts Basin, Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Johns, C. [Scott Pickford Group, Surrey (United Kingdom); Chine, A. [Entreprise Tunisienne d`Activites Petrolieres (ETAP), Tunis (Tunisia)

    1995-08-01

    The Chotts Basin, running east-west across central Tunisia, is a complex Late Paleozoic to Mesozoic graben system with a sediment thickness reaching over 5000m. It covers an area of over 15,000 km{sup 2} but is underexplored. It has been drilled by only a few wells; several of which gave oil and gas shows. A number of oil and condensate fields lie immediately south. ETAP, the national oil company, has undertaken a detailed investigation of the basin, greatly improving our understanding of its evolution and prospectivity. The basin is floored by Lower Paleozoic sediments. These occur at shallow depth on the southern flank where they were affected by periodic contemporary tectonism. The succession includes Ordovician clastics with good reservoir potential and both Ordovician and uppermost Silurian source rocks. Locally, the latter unconformably overlie Ordovician reservoir sections. The basin developed into a major, east-west trending, intracratonic wrench basin during the late Permian. Carbonate facies dominate the southern shelf area and, although lithofacies distributions are poorly constrained, the existence of quality source rocks is a strong possibility. The graben complex was inverted and partly eroded prior to deposition of Upper Triassic volcanics and sandstones. The sandstones are a proven reservoir and several leads are identified. Substantial subsidence occurred in the northern part of the basin from the Middle Jurassic to Early Cretaceous. Jurassic carbonates provide numerous reservoir sections, while Callovian shales constitute a proven, mature source rock. Large fault- and fold- related traps were formed during latest Cretaceous to Paleocene and Mio-Pliocene orogeny; they provide promising objectives.

  15. Carbonate redistribution, element mobilisation and petroleum hydrocarbon migration in Posidonia shale (Hils basin, NW Germany) as a function of palaeotemperature load from the Vlotho mass; Karbonatumverteilung, Mobilisation von Elementen und Migration von Erdoel-Kohlenwasserstoffen im Posidonienschiefer (Hilsmulde, NW-Deutschland) in Abhaengigkeit von der Palaeotemperaturbeanspruchung durch das Massiv von Vlotho

    Energy Technology Data Exchange (ETDEWEB)

    Jochum, J.

    1993-04-01

    Temperature-controlled processes of carbonate redistribution, element mobilisation and petroleum hydrocarbon migration in the Posidonia shale of North West Germany (Lower Toarcian) were documented, and a statistical evaluation was made. The investigations focused on six Posidonia shales of the Hils basin which had been exposed to increasing palaeotemperature stress from SE to NW in the direction of the injected mass of Vlotho. According to earlier investigations, the mean values of vitrinite reflection in the six boreholes are between 0.48% Rm and 1.45% Rm. This corresponds to a maximum palaeotemperature of 93-190 C. (orig./EF) [Deutsch] Im Rahmen der vorliegenden Arbeit wurden temperaturgesteuerte Prozesse der Umverteilung von Karbonaten, der Mobilisation von Elementen und der Migration von Erdoel-Kohlenwasserstoffen im nordwestdeutschen Posidonienschiefer (Unteres Toarcium) dokumentiert und bilanziert. Gegenstand der Untersuchungen waren sechs Posidonienschieferprofile aus dem Bereich der Hilsmulde, die von SE and NW in Annaeherung an das Intrusivmassiv von Vlotho eine zunehmende Palaeotemperaturbeanspruchung erfahren haben. Frueheren Untersuchungen zufolge liegen die Mittelwerte der Vitrinitreflexion in den sechs Bohrungen zwischen 0,48% Rm und 1,45% Rm, was einem Bereich der maximal erreichten Palaeotemperatur zwischen ca. 93 C und ca. 190 C entspricht. (orig./EF)

  16. Nitrogen fluxes in the forests of the Congo Basin

    Science.gov (United States)

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

    2017-04-01

    The tropical forest of the Congo basin remains very poorly investigated and understood; mainly because of logistic, political and research capacity constraints. Nevertheless, characterization and monitoring of fundamental processes in this biome is vital to understand future responses and to correctly parameterize Earth system models. Nutrient fluxes are key in these processes for the functioning of tropical forests, since 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. Research in the Congo Basin region should combine assessments of both carbon fluxes and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for nitrogen fluxes in four different forest types in the Congo Basin, resulting in a unique and integrate dataset. The questions to be answered: How do the N-budgets of four different forest types in the Congo Basin compare? How do these fluxes compare to fluxes in the Amazon forest? What is the influence from the strong slash-and-burn regimes on the N-cycle in the natural forests? We answer these questions with our empirical dataset of one hydrological year, combined with satellite and modeling data.

  17. Tuff beds in Kurnool subbasin, southern India and implications for felsic volcanism in Proterozoic intracratonic basins

    Directory of Open Access Journals (Sweden)

    Dilip Saha

    2012-07-01

    Full Text Available A first report on tuff beds from the Owk Shale in the Proterozoic Kurnool sub-basin in southern India is presented. The rhyolitic to rhodacitic tuffs, overlying shelfal limestones formed at depths below storm wave base, have rheomorphic features indicative of viscoplastic flow, and geochemical signatures of rhyolitic to rhyodacitic unwelded to welded tuffs, similar to those described from other Proterozoic intracratonic basins like Vindhyan and Chhattisgarh basins in India. Fragmentary nature of altered glass with perlitic cracks and local admixture with intrabasinal sediments suggest phreatomagmatic reactions. The widespread and repeated occurrences of felsic tuffs in these basins, possibly derived from low degree melting of continental crust, suggest intermittent tectonothermal instability which likely influenced basinal topography and cyclic development of the carbonate platforms.

  18. Ground-water resources in the Hood Basin, Oregon

    Science.gov (United States)

    Grady, Stephen J.

    1983-01-01

    The Hood Basin in north-central Oregon consists of about a 1 ,035-square-mile area underlain by Miocene to Holocene age volcanic, volcaniclastic, sedimentary rocks, and unconsolidated surficial deposits. The most important aquifer is the Columbia River Basalt Group, a unit that underlies most of the basin and probably exceeds a thickness of 2,000 feet wherever it is present. By 1980, only the upper 1,000 feet or less of the formation has been developed for water supplies. Most of this development is in the semiarid eastern half of the basin. Wells in the aquifer unit generally yield from 15 to 1,000 gallons per minute and a few yield as much as 3,300 gallons per minute. Other aquifer units in the basin have more limited areal extent and smaller saturated thickness than does the Columbia River Basalt Group. Generally, these units are capable of yielding from a few to a few hundred gallons per minute to wells. Most of the ground water in the basin is chemically suitable for domestic, irrigation, or other uses. Some ground water has objectionable concentrations of iron (0.3 to 6.4 mg/l) and manganese (0.05 to 1.2 mg/l) or is moderately hard to very hard (60 to 260 mg/l) as calcium carbonate. (USGS)

  19. Diagenesis of Malmian Marlstones, Vienna Basin

    Science.gov (United States)

    Schicker, A.; Gier, S.

    2009-04-01

    Burial diagenetic processes of pelitic sediments have been the subject of mineralogical investigations in Tertiary basins all over the world. Because of oil exploration, the investigations were focused on the Gulf Coast region in the United States. The diagenetic reaction from smectite to illite can be related to petroleum migration processes. The aim of this study is to characterize the diagenetic development of the Jurassic marls of the Mikulov Formation in the Vienna Basin. The Vienna Basin is located in the NE part of Austria and extends into Slovakia and the Czech Republic. It is a Tertiary pull-apart basin along the junction of the Eastern Alps and the Western Carpathians. The evolution of the basin started during the early Miocene with subsidence along NE trending sinistral faults. It is underlain by alpine thrusted nappes and autochthonous Mesozoic sediments. The clay mineralogy of 46 core samples from nine different wells was analyzed with X-ray diffraction and quantified. The wells penetrate the Mikulov Formation over a depth range of 1000 m to 8500 m which gives a unique opportunity to study the diagenetic changes of one formation from shallow to deep burial. Also, by following a single formation to depth, it is possible to minimize variations which might result from differences in provenance and depositional environment. For separation of the < 2 µm fraction the carbonate was dissolved with a 0.1 M EDTA-solution before sedimentation. The clay fraction contains a prominent illite/smectite (I/S) mixed-layer mineral, illite, chlorite and kaolinite. The amounts of I/S and kaolinite decrease with depth, illite and chlorite increase with depth. A diagenetic overprint was revealed, involving a gradual transformation of smectite to illite through mixed-layer I/S intermediates. The illite content in I/S ranges from 25% for the shallowest sample to 90% for the deepest sample. The ordering of the mixed layer I/S changes with increasing depth from R0 (25% illite

  20. Geohydrologic framework of the Roswell ground-water basin, Chaves and Eddy Counties, New Mexico

    Science.gov (United States)

    Welder, G.E.

    1983-01-01

    This report describes the geohydrology of the Roswell ground-water basin and shows the long-term hydrostatic-head changes in the aquifers. The Roswell ground-water basin consists of a carbonate artesian aquifer overlain by a leaky confining bed, which, in turn is overlain by an alluvial water-table aquifer. The water-table aquifer is hydraulically connected to the Pecos River. Ground-water pumpage from about 1,500 wells in the basin was about 378,000 acre-feet in 1978. Irrigation use on about 122,000 acres accounted for 95 percent of that pumpage.

  1. The evolution of the East Java Basin, Indonesia

    Science.gov (United States)

    Shields, Martin L.

    The East Java Basin has a geological life span of more than 50 Ma, with a diverse structural and stratigraphic development history. The basin originated during the Eocene on continental crust and developed northeast to southwest trending linear paleo-highs at its inception. These antiformal uplifts are cored by contractional structures, but also exhibit minor crestal extension. The parallel and convex paleo-highs are separated at a spatial wavelength of 80--100 km. The well and sediment information is recorded and evaluated herein as subsidence histories. By coupling the convex profiles from geohistory information with low heat flows recorded in well bottomhole temperatures, the evidence points to an origin of lithospheric flexure and buckling of the continental crust. The stratigraphy documented in well and outcrop samples indicates a preponderance of shelfal carbonate deposits with an influx of quartz sandstone during the Miocene. The quartzite source is north of the basin in Borneo associated with an exposed granite massif. Only Pliocene-Recent sediments (<5 Ma) are sourced from adjacent volcanic eruptions to the south. In contrast to previous studies where rifting is proposed as the mechanism for basin initiation, the evidence uncovered in this research points to crustal buckling of continental crust as the correct mechanism. Well subsidence histories indicate folding or flexure of the continental crust caused by contraction of the lithosphere appears to be responsible for Eocene-Miocene basin subsidence. The research evidence suggests the basin developed in four stages identified in the structure and stratigraphy captured in the geohistory profiles. The first stage of East Java Basin development, crustal buckling originated with Middle Eocene with sediments deposited in geographic lows on folded continental crust. Stage two, the flexural deepening phase started in the Late Oligocene with gradual subsidence until the Lower Miocene. The third phase, foreland

  2. GRAVITY-FLOW DEPOSITS IN THE TOARCIAN PERBLA FORMATION (SLOVENIAN BASIN, NW SLOVENIA

    Directory of Open Access Journals (Sweden)

    BOSTJAN ROZIC

    2011-07-01

    Full Text Available The Perbla Formation represents typical Toarcian clay-rich pelagic sediment of the southern Tethyan passive continental margin. It was deposited in the Slovenian Basin, located in present-day western Slovenia. During the Early Jurassic the basin was surrounded by the Dinaric (Friuli Carbonate Platform to the south and by the Julian Carbonate Platform to the north. Today, the transitional areas between the platforms and basin are not preserved due to intense Cainozoic thrusting and erosion, with the only record of the evolution of these areas stored in gravity-flow deposits of the Perbla Formation. Coarser turbidites were deposited on the margins of the basin, with other types of gravity-flow deposits, observed mainly in the central part of the basin. These intercalations reflect regionally recognized events that characterized the sedimentary evolution of western Slovenia at the end of the Early Jurassic. Slumps that occasionally developed into debris-flows reflect uneven sea-bottom palaeotopography that originated during a pre- to early-Toarcian phase of accelerated subsidence. The early Toarcian transgression caused drowning of the adjacent carbonate platforms, an event reflected in the composition of coarser turbidites which consist almost exclusively of echinoderm fragments and thin-shelled bivalves. These turbidites originated from drowned platform margins and/or slopes and were subsequently redeposited in proximal parts of the basin

  3. Great Carbonate Bank of Yucatan, Southern Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Viniegra-O, F.

    1981-01-01

    Since 1972, numerous large and giant oil fields have been discovered in the Reforma area of Chiapas and Tabasco States, southern Mexico, and on the offshore Campeche shelf west of Campeche State. The huge carbonate bank with which these discoveries are associated is called the Great Carbonate Bank of Yucatan. Present trap structures are mainly fractured and faulted domal salt pillows created during the Laramide orogeny. The Great Carbonate Bank of Yucatan is believed to include not just the Yucatan Peninsula, but also a part of coastal Veracruz State, where several discoveries have been made in carbonate rocks of Early to Middle Cretaceous ages in thrust sheets along the western margin of the Veracruz basin, which are now buried beneath the coastal plain. It is probable that large, subthrust, anticlinal structures underlie the thrust sheets along the western margin of the Veracruz basin, and these when drilled, may contain important hydrocarbon accumulations. (JMT)

  4. The deep Ionian Basin revisited

    Science.gov (United States)

    Tugend, Julie; Chamot-Rooke, Nicolas; Arsenikos, Stavros; Frizon de Lamotte, Dominique; Blanpied, Christian

    2016-04-01

    The deep Eastern Mediterranean Basins (Ionian and Herodotus) are characterized by thick sedimentary sequences overlying an extremely thinned basement evidenced from different geophysical methods. Yet, the nature of the crust (continental or oceanic) and the timing of the extreme crustal and lithosphere thinning in the different sub-basins remain highly controversial, casting doubts on the tectonic setting related to the formation of this segment of the North Gondwana paleo-margin. We focus on the Ionian Basin located at the western termination of the Eastern Mediterranean with the aim of identifying, characterizing and mapping the deepest sedimentary sequences. We present tentative age correlations relying on calibrations and observations from the surrounding margins and basins (Malta shelf and Escarpment, Cyrenaica margin, Sirte Basin, Apulian Platform). Two-ship deep refraction seismic data (Expanding Spread Profiles from the PASIPHAE cruise) combined with reprocessed reflection data (from the ARCHIMEDE survey) enabled us to present a homogeneous seismic stratigraphy across the basin and to investigate the velocity structure of its basement. Based on our results, and on a review of geological and geophysical observations, we suggest an Upper Triassic-Early Dogger age for the formation of the deep Ionian Basin. The nature of the underlying basement remains uncertain, both highly-thinned continental and slow-spreading type oceanic crust being compatible with the available constraints. The narrow size and relatively short-lived evolution of the Ionian Basin lead us to suggest that it is more likely the remnant of an immature oceanic basin than of a stable oceanic domain. Eventually, upscaling these results at the scale of the Eastern Mediterranean Basins highlights the complex interaction observed between two propagating oceans: The Central Atlantic and Neo-Tethys.

  5. Geochemistry of the Birch Creek Drainage Basin, Idaho

    Science.gov (United States)

    Swanson, Shawn A.; Rosentreter, Jeffrey J.; Bartholomay, Roy C.; Knobel, LeRoy L.

    2003-01-01

    The U.S. Survey and Idaho State University, in cooperation with the U.S. Department of Energy, are conducting studies to describe the chemical character of ground water that moves as underflow from drainage basins into the eastern Snake River Plain aquifer (ESRPA) system at and near the Idaho National Engineering and Environmental Laboratory (INEEL) and the effects of these recharge waters on the geochemistry of the ESRPA system. Each of these recharge waters has a hydrochemical character related to geochemical processes, especially water-rock interactions, that occur during migration to the ESRPA. Results of these studies will benefit ongoing and planned geochemical modeling of the ESRPA at the INEEL by providing model input on the hydrochemical character of water from each drainage basin. During 2000, water samples were collected from five wells and one surface-water site in the Birch Creek drainage basin and analyzed for selected inorganic constituents, nutrients, dissolved organic carbon, tritium, measurements of gross alpha and beta radioactivity, and stable isotopes. Four duplicate samples also were collected for quality assurance. Results, which include analyses of samples previously collected from four other sites, in the basin, show that most water from the Birch Creek drainage basin has a calcium-magnesium bicarbonate character. The Birch Creek Valley can be divided roughly into three hydrologic areas. In the northern part, ground water is forced to the surface by a basalt barrier and the sampling sites were either surface water or shallow wells. Water chemistry in this area was characterized by simple evaporation models, simple calcite-carbon dioxide models, or complex models involving carbonate and silicate minerals. The central part of the valley is filled by sedimentary material and the sampling sites were wells that are deeper than those in the northern part. Water chemistry in this area was characterized by simple calcite-dolomite-carbon dioxide

  6. Recycling an uplifted early foreland basin fill: An example from the Jaca basin (Southern Pyrenees, Spain)

    Science.gov (United States)

    Roigé, M.; Gómez-Gras, D.; Remacha, E.; Boya, S.; Viaplana-Muzas, M.; Teixell, A.

    2017-10-01

    In the northern Jaca basin (Southern Pyrenees), the replacement of deep-marine by terrestrial environments during the Eocene records a main drainage reorganization in the active Pyrenean pro-wedge, which leads to recycling of earlier foreland basin sediments. The onset of late Eocene-Oligocene terrestrial sedimentation is represented by four main alluvial fans: Santa Orosia, Canciás, Peña Oroel and San Juan de la Peña, which appear diachronously from east to west. These alluvial fans are the youngest preserved sediments deposited in the basin. We provide new data on sediment composition and sources for the late Eocene-Oligocene alluvial fans and precursor deltas of the Jaca basin. Sandstone petrography allows identification of the interplay of axially-fed sediments from the east with transversely-fed sediments from the north. Compositional data for the alluvial fans reflects a dominating proportion of recycled rock fragments derived from the erosion of a lower to middle Eocene flysch depocentre (the Hecho Group), located immediately to the north. In addition, pebble composition allows identification of a source in the North Pyrenean Zone that provided lithologies from the Cretaceous carbonate flysch, Jurassic dolostones and Triassic dolerites. Thus we infer this zone as part of the source area, located in the headwaters, which would have been unroofed from turbidite deposits during the late Eocene-Oligocene. These conclusions provide new insights on the response of drainage networks to uplift and topographic growth of the Pyrenees, where the water divide migrated southwards to its present day location.

  7. Characterization of hydraulic conductivity of the alluvium and basin fill, Pinal Creek Basin near Globe, Arizona

    Science.gov (United States)

    Angeroth, Cory E.

    2002-01-01

    Acidic waters containing elevated concentrations of dissolved metals have contaminated the regional aquifer in the Pinal Creek Basin, which is in Gila County, Arizona, about 100 kilometers east of Phoenix. The aquifer is made up of two geologic units: unconsolidated stream alluvium and consolidated basin fill. To better understand how contaminants are transported through these units, a better understanding of the distribution of hydraulic conductivity and processes that affect it within the aquifer is needed. Slug tests were done in September 1997 and October 1998 on 9 wells finished in the basin fill and 14 wells finished in the stream alluvium. Data from the tests were analyzed by using either the Bouwer and Rice (1976) method, or by using an extension to the method developed by Springer and Gellhar (1991). Both methods are applicable for unconfined aquifers and partially penetrating wells. The results of the analyses show wide variability within and between the two geologic units. Hydraulic conductivity estimates ranged from 0.5 to 250 meters per day for the basin fill and from 3 to 200 meters per day for the stream alluvium. Results of the slug tests also show a correlation coefficient of 0.83 between the hydraulic conductivity and the pH of the ground water. The areas of highest hydraulic conductivity coincide with the areas of lowest pH, and the areas of lowest hydraulic conductivity coincide with the areas of highest pH, suggesting that the acidic water is increasing the hydraulic conductivity of the aquifer by dissolution of carbonate minerals.

  8. Characteristics of the Triassic Source Rocks of the Aitutu Formation in the (West) Timor Basin

    OpenAIRE

    Asep Kurnia Permana; Aries Kusworo; Andi Heri Prastian

    2014-01-01

    DOI:10.17014/ijog.v1i3.192The Triassic rocks of the (West) Timor Basin have been identified that was mainly deposited in the  marine environment. The fine grained clastics and carbonate  rocks of this Triassic marine  facies are considered to be the most promising source rocks potential in this basin. In this paper we present geochemical and petrographic data from outcrop samples of the Triassic carbonate Aitutu Formation, due to emphasized the organic maturation, kerogen type of the organic ...

  9. Dimension of Fractal Basin Boundaries.

    Science.gov (United States)

    Park, Bae-Sig

    In many dynamical systems, multiple attractors coexist for certain parameter ranges. The set of initial conditions that asymptotically approach each attractor is its basin of attraction. These basins can be intertwined on arbitrary small scales. Basin boundary can be either smooth or fractal. Dynamical systems that have fractal basin boundary show "final state sensitivity" of the initial conditions. A measure of this sensitivity (uncertainty exponent alpha) is related to the dimension of the basin boundary d = D - alpha , where D is the dimension of the phase space and d is the dimension of the basin boundary. At metamorphosis values of the parameter, there might happen a conversion from smooth to fractal basin boundary (smooth-fractal metamorphosis) or a conversion from fractal to another fractal basin boundary characteristically different from the previous fractal one (fractal-fractal metamorphosis). The dimension changes continuously with the parameter except at the metamorphosis values where the dimension of the basin boundary jumps discontinuously. We chose the Henon map and the forced damped pendulum to investigate this. Scaling of the basin volumes near the metamorphosis values of the parameter is also being studied for the Henon map. Observations are explained analytically by using low dimensional model map. We look for universal scalings of the dimension of fractal basin boundaries near type I and type III intermittency transitions to chaos. Type I intermittency can occur as the system experiences a saddle-node (tangent) bifurcation and type III intermittency can occur as the system experiences an inverted period doubling bifurcation. At these bifurcations, multiple attractors with fractal basin boundaries can be created. It is found the dimension scales, with the parameter, according to the power law d = d_{o } - k| p - p_{c}| ^{beta} with beta = 1/2, where p is the system parameter, p _{c} is the bifurcation value, k is a scaling constant, and d_{o} is

  10. Transition from marine deep slope deposits to evaporitic facies of an isolated foreland basin: case study of the Sivas Basin (Turkey)

    Science.gov (United States)

    Pichat, Alexandre; Hoareau, Guilhem; Legeay, Etienne; Lopez, Michel; Bonnel, Cédric; Callot, Jean-Paul; Ringenbach, Jean-Claude

    2017-04-01

    The Sivas Basin, located in the central part of the Anatolian Plateau in Turkey, formed after the closure of the northern Neotethys from Paleocene to Pliocene times. It developed over an ophiolitic basement obducted from the north during the Late Cretaceous. During Paleocene to Eocene times, the onset of the Tauride compression led to the development of a foreland basin affected by north-directed thrusts. The associate general deepening of the basin favored the accumulation of a thick marine turbiditic succession in the foredeep area, followed by a fast shallowing of the basin and thick evaporitic sequence deposition during the late Eocene. We present here the detailed sedimentological architecture of this flysch to evaporite transition. In the northern part of the basin, volcanoclastic turbidites gradually evolved into basinal to prodelta deposits regularly fed by siliciclastic material during flood events. Locally (to the NE), thick-channelized sandstones are attributed to the progradation of delta front distributary channels. The basin became increasingly sediment-starved and evolved toward azoic carbonates and shaly facies, interlayered with organic-rich shales before the first evaporitic deposits. In the southern part of the basin, in the central foredeep, the basinal turbidites become increasingly gypsum-rich and record a massive mega-slump enclosing olistoliths of gypsum and of ophiolitic rocks. Such reworked evaporites were fed by the gravitational collapsing of shallow water evaporites that had previously precipitated in silled piggy-back basins along the southern fold-and-thrust-belt of the Sivas Basin. Tectonic activity that led to the dismantlement of such evaporites probably also contributed to the closure of the basin from the marine domain. From the north to the south, subsequent deposits consist in about 70 meters of secondary massive to fine-grained gypsiferous beds interpreted as recording high to low density gypsum turbidites. Such facies were

  11. K-Basins design guidelines

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-06-01

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

  12. Characterization of the Lower Wolfcamp, Midland Basin, Texas, using subsurface stratigraphic and geochemical datasets.

    Science.gov (United States)

    Perlman, Z. S.; Ryan, P. T.; Baldwin, P.; Lucas, J.; McGlue, M. M.; Waite, L.; Woodruff, O. P.

    2016-12-01

    In recent years, the Midland Basin of west Texas has resurfaced as a strong and viable unconventional oil field, especially within the late Pennsylvanian-Early Permian section. In addition to exploring for hydrocarbons, studying this basin allows for a better understanding of the paleoceanographic and paleoenvironmental conditions that prevailed during deposition. This research focuses on subsurface data from the Lower Wolfcamp interval of the northern Midland Basin proximal to the Horseshoe Atoll. Chemostratigraphic and lithostratigraphic analyses were conducted on 388 ft of continuous drill core extracted from Martin County, Texas. Comprehensive analyses revealed repetitive stacking of organic-rich siliceous mudrocks, aluminum-rich clayey mudrocks, and diverse carbonate facies. High resolution energy dispersive X-ray fluorescence data demonstrate cyclic variability in silicon, aluminum, and calcium weight percentages. These data suggest that during the time of deposition, the Midland Basin was a mixed siliciclastic-carbonate system influenced by a global icehouse climate with high frequency glacio-eustatic sea level fluctuations. Organic carbon preservation at this time was at least partially influenced by bottom water redox conditions. Elemental trace metal data suggests the potential for anoxia and possibly euxinia, likely influenced by recharge from the Panthalassic Ocean. Stratal evidence for bottom water conditions and patterns of organic enrichment vary across the basin and in vertical succession; these factors may be explained by evolving oceanographic processes and environmental gradients within the basin. The timing of Lower Wolfcamp deposition may be Late Pennsylvanian, based on correlations to fusulinids in shelfal carbonates. Thus, our preliminary interpretations focus on Lower Wolfcamp strata as a condensed package of deep-basin cyclothems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hautevelle, Y

    2005-12-15

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

  14. Geologic Basin Boundaries (Basins_GHGRP) GIS Layer

    Data.gov (United States)

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

  15. Petroleum geology and resources of the Amu-Darya basin, Turkmenistan, Uzbekistan, Afghanistan, and Iran

    Science.gov (United States)

    Ulmishek, Gregory F.

    2004-01-01

    The Amu-Darya basin is a highly productive petroleum province in Turkmenistan and Uzbekistan (former Soviet Union), extending southwestward into Iran and southeastward into Afghanistan. The basin underlies deserts and semideserts north of the high ridges of the Kopet-Dag and Bande-Turkestan Mountains. On the northwest, the basin boundary crosses the crest of the Karakum regional structural high, and on the north the basin is bounded by the shallow basement of the Kyzylkum high. On the east, the Amu-Darya basin is separated by the buried southeast spur of the Gissar Range from the Afghan-Tajik basin, which is deformed into a series of north-south-trending synclinoria and anticlinoria. The separation of the two basins occurred during the Neogene Alpine orogeny; earlier, they were parts of a single sedimentary province. The basement of the Amu-Darya basin is a Hercynian accreted terrane composed of deformed and commonly metamorphosed Paleozoic rocks. These rocks are overlain by rift grabens filled with Upper Permian-Triassic rocks that are strongly compacted and diagenetically altered. This taphrogenic sequence, also considered to be a part of the economic basement, is overlain by thick Lower to Middle Jurassic, largely continental, coal-bearing rocks. The overlying Callovian-Oxfordian rocks are primarily carbonates. A deep-water basin surrounded by shallow shelves with reefs along their margins was formed during this time and reached its maximum topographic expression in the late Oxfordian. In Kimmeridgian-Tithonian time, the basin was filled with thick evaporites of the Gaurdak Formation. The Cretaceous-Paleogene sequence is composed chiefly of marine clastic rocks with carbonate intervals prominent in the Valanginian, Barremian, Maastrichtian, and Paleocene stratigraphic units. In Neogene time, the Alpine orogeny on the basin periphery resulted in deposition of continental clastics, initiation of new and rejuvenation of old faults, and formation of most structural

  16. Great Basin Experimental Range: Annotated bibliography

    Science.gov (United States)

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

    2013-01-01

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

  17. Isotopic and chemical composition (δ13C, Δ14C, δ15N, C:N, SUVA254nm, % HPOA) of aquatic carbon and field conditions (water temperature, pH, discharge) in the Upper Mississippi River Basin, October 2014 – February 2016

    Data.gov (United States)

    Department of the Interior — This dataset contains stable isotope (δ13C) and radioisotope (Δ14C) compositions of dissolved inorganic carbon, dissolved organic carbon, particulate organic carbon,...

  18. Trip report Rainwater Basin Nebraska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is a summary a trip to Rainwater Basin Wetland Management District in 1991, and focuses on the hydrology and soil habitat types. It is part of the...

  19. Allegheny County Basin Outlines Map

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This basins dataset was created to initiate regional watershed approaches with respect to sewer rehabilitation. If viewing this description on the Western...

  20. Geochemical and isotopic characteristics of groundwater from Velenje Basin, Slovenia

    Science.gov (United States)

    Kanduč, Tjaša; Grassa, Fausto; Mori, Nataša; Verbovšek, Timotej

    2016-04-01

    The Velenje Basin in Slovenia is one of the largest actively mined coal basins in central Europe, producing around 4 million tons of lignite per year. Large amounts of groundwater are extracted from aquifers to facilitate underground mining of coal, and coal seam gas outbursts are a serious mine safety concern. This study analyses the geochemical and isotopic composition of groundwater to provide a general understanding of hydrogeological and geochemical processes in groundwater. Thirty-eight groundwater samples were taken from dewatering objects in the mine and at the surface in years 2014-2015. Groundwater in the Triassic aquifer is dominated by hydrogen carbonate, calcium, magnesium and isotopic composition of dissolved inorganic carbon in the range from -19.3 to -2.8‰ indicating degradation of soil organic matter and dissolution of carbonate minerals. In contrast, groundwater in the Pliocene aquifers is enriched in magnesium, sodium, calcium, potassium, and silicon, and has high alkalinity, with isotopic composition of dissolved inorganic carbon in the range of -14.4 to +4.6‰ . Based on isotopic composition of dissolved inorganic carbon values in all aquifers (Pliocene and Triassic), influencing processes are the dissolution of carbonate minerals and dissolution of organic matter, and additionally methanogenesis in the Pliocene aquifers. Based on the Principal Component Analysis (PCA) we can conclude that following different types of groundwater in Velenje Basin could be distinguished based on geochemical and isotopic data: Triassic aquifers with higher pH and lower conductivity and chloride, Pliocene, Pliocene 1 and Pliocene 2 aquifers with lower pH and higher conductivity and chloride contents, and Pliocene 3 and Pliocene 2, 3 aquifers with the highest pH and lowest conductivity and chloride contents. Major dissolved gas component in groundwater are carbon dioxide, nitrogen and methane. Concentrations of dissolved gases dewatering Triassic strata are low

  1. Rain Basin Design Implications for Soil Microbial Activity and N-mineralization in a Semi-arid Environment

    Science.gov (United States)

    Stern, C.; Pavao-Zuckerman, M.

    2014-12-01

    Rain basins have been an increasingly popular Green Infrastructure (GI) solution to the redistribution of water flow caused by urbanization. This study was conducted to examine how different approaches to basin design, specifically mulching (gravel vs. compost and gravel), influence the water availability of rain basins and the effects this has on the soil microbial activity of the basins. Soil microbes are a driving force of biogeochemical process and may impact the carbon and nitrogen dynamics of rain basin GI. In this study we sampled 12 different residential-scale rain basins, differing in design established at Biosphere 2, Arizona in 2013. Soil samples and measurements were collected before and after the onset of the monsoon season in 2014 to determine how the design of basins mediates the transition from dry to wet conditions. Soil abiotic factors were measured, such as moisture content, soil organic matter (SOM) content, texture and pH, and were related to the microbial biomass size within the basins. Field and lab potential N-mineralization and soil respiration were measured to determine how basin design influences microbial activity and N dynamics. We found that pre-monsoon basins with compost had higher moisture contents and that there was a positive correlation between the moisture content and the soil microbial biomass size of the basins. Pre-monsoon data also suggests that N-mineralization rates for basins with compost were higher than those with only gravel. These design influences on basin-scale biogeochemical dynamics and nitrogen retention may have important implications for urban biogeochemistry at neighborhood and watershed scales.

  2. Late Aptian-Albian of the Vocontian Basin (SE-France) and Albian of NE-Texas: Biostratigraphic and paleoceanographic implications by planktic foraminifera faunas

    OpenAIRE

    Reichelt, Kerstin

    2005-01-01

    Planktic foraminifera fauna and carbon isotopes of the bulk rock have been investigated to compile a high resolution biostratigraphy for the Late Aptian to Late Albian in the Vocontian Basin (SE-France) and for the Middle and Late Albian in NE-Texas. A high resolution carbon isotope stratigraphy (CIS) has been established for the Albian of the Vocontian Basin, and partially correlated with sections in the eastern (ODP 547, Mazagan Plateau) and western (ODP 1052; Blake Nose Plateau) Atlantic a...

  3. Integrated stratigraphy of the late Campanian - Maastrichtian in the Danish Basin

    DEFF Research Database (Denmark)

    Boussaha, Myriam; Thibault, Nicolas Rudolph; Stemmerik, Lars

    2016-01-01

    New stratigraphic (calcareous nannofossils and carbon isotope) and sedimentological results from the upper Campanian – Maastrichtian of the Stevns-2 core, Denmark, allow for regional correlations and building of a solid age-model with the definition of 17 stratigraphic tie-points in the Danish Ba...... is presented for the Danish Basin, calibrated in age and correlated to high-resolution carbon isotope stratigraphy. Common, regional changes in sediment accumulation rates highlight trends that appear linked to climatic conditions....

  4. Inorganic carbon shortage may limit the development of submersed macrophytes in habitats of the Paraná River basin Baixas concentrações de carbono inorgânico podem limitar o desenvolvimento de macrófitas submersas em habitats do alto rio Paraná

    Directory of Open Access Journals (Sweden)

    Aline de Freitas

    2011-03-01

    Full Text Available AIM: In this investigation we carried out an experiment to assess whether the growth of Egeria najas and E. densa (two rooted submersed Hydrocharitacea, native to South America are limited by inorganic carbon or not; METHODS: We measured the early plant growth in 3 L microcosms with alkalinities of 100 µM.L-1 and 500 µM.L-1. These alkalinites represent extremes which are typical of most waters in the Upper Paraná River basin and they represent low and high inorganic carbon (mainly bicarbonate availabilities, respectively; RESULTS: The elongation of E. densa, and the relative growth rates and root development of both species were significantly higher when they grew in the high alkalinity treatment; CONCLUSIONS: Our results strongly suggest that in several habitats and during certain periods of the year, inorganic carbon shortage may limit the growth of both species. In this sense, phosphorus and nitrogen may assume a secondary role as controlling factors of these plants, because they assimilate these nutrients from sediment, where they are usually found in high concentrations. Thus, controlling eutrofication as a strategy to reduce their biomass may not be successful.OBJETIVOS: Nesse trabalho nós realizamos um experimento para avaliar se o crescimento de Egeria najas e E. densa (duas espécies de macrófitas aquáticas submersas da família Hydrocharitaceae, nativas da América do Sul é limitado por carbono inorgânico; MÉTODOS: Nós medimos os estágios iniciais de crescimento de fragmentos em microcosmos de 3 L com alcalinidade de 100 µM.L-1 e 500 µM.L-1. Esses valores de alcalinidade foram escolhidos por representarem extremos típicos da maioria dos ecossistemas aquáticos da bacia do Alto rio Paraná e representaram baixa e alta disponibilidade de carbono (principalmente bicarbonato, respectivamente; RESULTADOS: O alongamento de E. densa e o crescimento relativo e desenvolvimento de raízes de ambas as espécies foram

  5. Using hydrogeologic data to evaluate geothermal potential in the eastern Great Basin

    Science.gov (United States)

    Masbruch, Melissa D.; Heilweil, Victor M.; Brooks, Lynette E.

    2012-01-01

    In support of a larger study to evaluate geothermal resource development of high-permeability stratigraphic units in sedimentary basins, this paper integrates groundwater and thermal data to evaluate heat and fluid flow within the eastern Great Basin. Previously published information from a hydrogeologic framework, a potentiometric-surface map, and groundwater budgets was compared to a surficial heat-flow map. Comparisons between regional groundwater flow patterns and surficial heat flow indicate a strong spatial relation between regional groundwater movement and surficial heat distribution. Combining aquifer geometry and heat-flow maps, a selected group of subareas within the eastern Great Basin are identified that have high surficial heat flow and are underlain by a sequence of thick basin-fill deposits and permeable carbonate aquifers. These regions may have potential for future geothermal resources development.

  6. Geochemical characteristics of natural gas in the Yinggehai-Qiongdongnan Basin, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Fengrong Liao; Xiaoqi Wu; Shipeng Huang [PetroChina, Beijing (China). Research Institute of Petroleum Exploration & Development

    2010-03-15

    Geochemical characteristics of natural gas in the Yinggehai-Qiongdongnan Basin were studied and analyzed based on gas component properties and carbon isotopic characteristics which were tested and collected of more than 100 samples. The gas in the Yinggehai-Qiongdongnan Basin was generally alkane gas, and all the area showed dry gas characteristics except Yanan Depression and its periphery area. The gas in the Basin is mainly high mature-over mature coal formed gas except Songnan and eastern of the second fault belt. There are three genetic types of the natural gas in the Yinggehai-Qiongdongnan Basin, such as microbial gas, coal-formed gas and the mixture of them. The coal-formed gas is the main genetic type.

  7. Geological evolution, regional perspectives and hydrocarbon potential of the northwest Phu Khanh Basin, offshore Central Vietnam

    DEFF Research Database (Denmark)

    Fyhn, Michael Bryld Wessel; Nielsen, Lars H.; Boldreel, Lars Ole

    2009-01-01

      Seismic stratigraphic and structural analyses of the northwest Phu Khanh Basin, offshore Central Vietnam, based on 2-D seismic data, indicate that the initial rifting began during the latest Cretaceous? or Palaeogene controlled by left-lateral transtension along the East Vietnam Boundary Fault...... seeps are found at Dam Thi Nai, immediately landward of the basin. Geochemical analyses of the oil seeps indicate the existence of at least two early to peak mature source rocks. Maturation modelling, combined with the seismic analysis, suggests the likely presence of oil kitchens 40-50km downdip...... in the basin, and a fairly simple oil migration route. The basin is probably charged from lacustrine syn-rift mudstones, humic coals and fore-reef marls. Potential reservoirs are turbidite, lowstand delta, shelf and coastal sandstones, as well as platform and reef carbonates and fractured basement. Various...

  8. Composition and origin of coalbed gases in the Upper Silesian and Lublin basins, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Kotarba, M.J. [Stanislaw Staszic University of Mining and Metallurgy, Krakow (Poland)

    2001-07-01

    Coalbed gases in the Upper Silesian Coal Basin (USCB) are highly variable in molecular and stable isotope composition. Various geochemical indices and stable isotope ratios for coalbed gases from USCB and the Lublin Coal Basin (LCB) were determined. Methane, higher gaseous hydrocarbons (C{sub 2} to C{sub 5}) and carbon dioxide occurring in the coalbed gases in both the USCB and the LCB were generated during the bituminous stage of the coalification process and, probably, during microbial reduction of carbon dioxide. However, depth-related isotopic fractionation which has resulted from physical (e.g. diffusion and adsorption/desorption) processes during gas migration cannot be neglected. In both basins the coalification process lasted no longer than several Ma, and was completed at the end of the Variscan orogeny (at the turn of Carboniferous and Permian).

  9. 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

  10. Geology, compositional heterogeneities, and geochemical origin of the Yacheng gas field, Qiongdongnan Basin, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Hao, F.; Li, S.; Sun, Y. [China Univ. of Geosciences, Wuhan, Hubei (China). Dept. of Petroleum Geology; Zhang, Q. [Nanhai West Oil Corp., Guangdong (China). Inst. of Petroleum Exploration and Development

    1998-07-01

    The Yacheng gas field is located in the footwall of the No. 1 fault, the boundary fault between the Yinggehai and Qiongdongnan basins. All strata are normally pressured in the gas field except for the Meishan Formation. The Meishan Formation is overpressured near the No. 1 fault in the gas field and in the adjacent Yinggehai Basin. An obvious thermal anomaly occurs below 3600 m in the gas field. This anomaly, characterized by an abrupt increase in drill-stem test and fluid-inclusion homogenization temperatures, vitrinite reflectance (R{sub o}), and Rock-Eval T{sub max}, and by an abnormally low temperature/R{sub o}/T{sub max} gradient, diminishes away from the Yinggehai Basin. The gases and condensates have abnormally high aromatic hydrocarbon contents and show obvious heterogeneities. Away from the No. 1 fault, the C{sub 2+} hydrocarbon content and C{sub 2+}/{Sigma}C{sub n} increase; carbon dioxide content decreases; {delta}{sup 13}C values for methane, ethane, and carbon dioxide become lighter; the heptane and isoheptane values decrease; and the relative contents of aromatic hydrocarbons, both in C{sub 6}/C{sub 7} light hydrocarbons and in the condensates, decrease. The gas field was charged from both the Qiongdongnan and the Yinggehai basins. Hydrocarbons sourced from the Qiongdongnan Basin have relatively low maturities, whereas hydrocarbons from the Yinggehai Basin have relatively higher maturities and seem to have been in association with hydrothermal fluids. The hydrothermal fluids from the Yinggehai Basin, in which methane, ethane, carbon dioxide, and especially aromatic hydrocarbons dissolved under the high-temperature and high-pressure subsurface conditions, migrated along the No. 1 fault and caused the abnormally high concentration of aromatic hydrocarbons, as well as the thermal anomalies in the gas field, especially near the No. 1 fault.

  11. 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...

  12. Environmental isotope investigation of groundwater flow in the Honey Lake Basin, California and Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Rose, T.P.; Davisson, M.L.; Hudson, G.B.; Varian, A.R.

    1997-07-01

    The hydrology of Honey Lake Basin was studied using environmental isotope measurements of approximately 130 water samples collected during 1995 and 1996. The principal analytical methods included hydrogen, oxygen and carbon stable isotope ratio measurements, radiocarbon and tritium dating, and measurements of dissolved noble gas abundances.

  13. Deep-sea coral record of human impact on watershed quality in the Mississippi River Basin

    NARCIS (Netherlands)

    Prouty, N.G.; Roark, E.B.; Koenig, A.E.; Demopoulos, A.W.J.; Batista, F.C.; Kocar, B.D.; Selby, D.; McCarthy, M.D.; Mienis, F.

    2014-01-01

    One of the greatest drivers of historical nutrient and sediment transport into the Gulf of Mexico is the unprecedented scale and intensity of land use change in the Mississippi River Basin. These landscape changes are linked to enhanced fluxes of carbon and nitrogen pollution from the Mississippi

  14. Calcium Carbonate

    Science.gov (United States)

    Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not ... for healthy bones, muscles, nervous system, and heart. Calcium carbonate also is used as an antacid to relieve ...

  15. Structural imaging of the East Beni Sueif Basin, north eastern Desert, Egypt

    Science.gov (United States)

    Salem, E.; Sehim, A.

    2017-12-01

    The East Beni Sueif Basin is the only tested hydrocarbon-bearing basin on the eastern side of the Nile in Egypt. The basin is located around 150 km to the south of Cairo. This work introduces the first attempt of seismic interpretation and structural patterns of this basin, for which subsurface published works are lacking. Structural imaging of the area is achieved through interpretation of pre-stack time migration (PSTM) seismic cube and data sets of seven wells. The penetrated sedimentary section is represented by Albian-Middle Eocene sediments. The East Beni Sueif Basin is a type of the whole graben-system and is bounded by two NW-SE bounding faults. These faults had continued activity in an extensional regime associated with fault-propagating folds. The basin is traversed by a N75°E-trending fault system at basement level. This fault system separates the basin into two structural provinces. The Northwestern Province is deeper and shows more subsidence with a predominance of NW-trending longitudinal faults and N60·W oblique faults to the basin trend. The Southeastern Province is shallow and crossed by N14·W-trending faults which are slightly oblique to the basin axis. Albian time had witnessed the main extensional tectonic phase and resulted in major subsidence along basin-bounding faults associated with growth thickening of basal deposits. During Senonian time, the basin experienced a mild phase of transtensional tectonics, which formed negative-flower structures entrapping different folds along the N75°E and N60·W faults. The timing and style of these structures are similar to the Syrian-Arc structures in several Western Desert oil fields. The basin emerged during the Paleocene with scoured and eroded top Cretaceous sediments. Subsidence was resumed during the Early Eocene and resulted in 1500 m-thick carbonate sediments. Lastly, a mild extensional activity possibly occurred during the Oligocene-Miocene time. Despite the possible restricted potentiality

  16. Silurian K-bentonites of the Dnestr Basin, Podolia, Ukraine

    Science.gov (United States)

    Huff, W.D.; Bergstrom, Stig M.; Kolata, Dennis R.

    2000-01-01

    The Dnestr Basin of Podolia, Ukraine, is an epicratonic basin consisting of neritic carbonate and calcareous mudstone facies including a nearly complete Silurian sequence ranging from late Llandovery to late Pridoli in age. The Silurian section has served as a standard for regional and interregional studies as a consequence of its well-documented macro- and microfaunal assemblages. Approximately 24 mid- to Late Silurian K-bentonites are present in this succession, and their lateral persistence has aided in establishing regional correlations. The K-bentonites range from 1 to 40 cm in thickness and occur in the Bagovitsa (late Wenlock), Malinovtsy (Ludlow) and Skala (Pridoli) Formations. Discrimination diagrams based on immobile trace elements together with rare earth element data suggest the K-bentonites had a volcanic origin in a collision margin setting related to subduction. Thickness and stratigraphic distribution considerations are consistent with a source area in the Rheic Ocean.

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

    Science.gov (United States)

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

    2016-04-01

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

  18. Comparison of Tarim and central Asian FSU basins, II: Differences in hydrocarbon systems and possible explanations

    Energy Technology Data Exchange (ETDEWEB)

    Shangyou, N.; Heubeck, C. (Amoco Production Co., Houston, TX (United States))

    1996-01-01

    If the Tertiary crustal shortening and indentation in the Pamirs is restored palinspastically, it would be evident that the Central Asian basins in the FSU (including Amu Darya, Tajik, Fergana, and Syr Darya) in the west and the Tarim basin in the cast probably shared many similarities in their geological history after becoming part of the Eurasia continent in the Late Paleozoic. For example, both areas contain significant amounts of coal-bearing Jurassic sequences, and a marine connection no doubt existed between the two during the maximum marine transgression period of Late Cretaceous and Early Tertiary. A direct comparison is more difficult for the Paleozoic sequences because in the Central Asia basins, they are either buried too deeply or highly metamorphosed in the outcrops. It is interesting to note that these basins exhibit vast differences in the age and type of source and reservoir rocks. For the Tarim basin, most of the source rocks are Paleozoic (Ordovician and Carboniferous) and marine in nature, whereas in the Central Asian basins, the dominant source rocks are Jurassic and younger and include both marine and non-marine sequences. Similarly for the reservoir rocks, most of the hydrocarbons found in the Tarim basin is from the Paleozoic, (such as Devonian and Carboniferous clastics/carbonates), whereas in Amu Darya and Fergana basins, the reservoir rocks are dominated by Jurassic carbonates and Paleogene clastics respectively. This presentation will highlight these differences and address the probable causes mainly from the view points of tectonics and paleogeography. We conclude that the dominant effect is the Early Tertiary India-Asia collision, which caused significant differences in the distribution and thickness of the post-collisional clastic sediments, which in turn resulted in different maturation and migration history.

  19. Comparison of Tarim and central Asian FSU basins, II: Differences in hydrocarbon systems and possible explanations

    Energy Technology Data Exchange (ETDEWEB)

    Shangyou, N.; Heubeck, C. [Amoco Production Co., Houston, TX (United States)

    1996-12-31

    If the Tertiary crustal shortening and indentation in the Pamirs is restored palinspastically, it would be evident that the Central Asian basins in the FSU (including Amu Darya, Tajik, Fergana, and Syr Darya) in the west and the Tarim basin in the cast probably shared many similarities in their geological history after becoming part of the Eurasia continent in the Late Paleozoic. For example, both areas contain significant amounts of coal-bearing Jurassic sequences, and a marine connection no doubt existed between the two during the maximum marine transgression period of Late Cretaceous and Early Tertiary. A direct comparison is more difficult for the Paleozoic sequences because in the Central Asia basins, they are either buried too deeply or highly metamorphosed in the outcrops. It is interesting to note that these basins exhibit vast differences in the age and type of source and reservoir rocks. For the Tarim basin, most of the source rocks are Paleozoic (Ordovician and Carboniferous) and marine in nature, whereas in the Central Asian basins, the dominant source rocks are Jurassic and younger and include both marine and non-marine sequences. Similarly for the reservoir rocks, most of the hydrocarbons found in the Tarim basin is from the Paleozoic, (such as Devonian and Carboniferous clastics/carbonates), whereas in Amu Darya and Fergana basins, the reservoir rocks are dominated by Jurassic carbonates and Paleogene clastics respectively. This presentation will highlight these differences and address the probable causes mainly from the view points of tectonics and paleogeography. We conclude that the dominant effect is the Early Tertiary India-Asia collision, which caused significant differences in the distribution and thickness of the post-collisional clastic sediments, which in turn resulted in different maturation and migration history.

  20. Phosphate, carbonate and organic matter distribution in sediment cores off Bombay-Saurashtra coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.; Rao, Ch.M.

    Phosphate, organic matter and calcium carbonate content in five sediment cores (three from the outer shelf one from the slope and one from the basin) from the Arabian Sea have been determined. The distribution pattern indicates their close genetic...

  1. In search of a Silurian total petroleum system in the Appalachian basin of New York, Ohio, Pennsylvania, and West Virginia: Chapter G.11 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Ryder, Robert T.; Swezey, Christopher S.; Trippi, Michael H.; Lentz, Erika E.; Avary, K. Lee; Harper, John A.; Kappel, William M.; Rea, Ronald G.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    Oil and gas fields in Silurian carbonate and sandstone reservoirs in the Appalachian basin probably originated from one or more of the following source rocks: (1) Upper Ordovician Utica Shale, (2) Middle to Upper Devonian black shale, and (3) Lower to Upper Silurian shale and carbonate units. In this reconnaissance study, selected Silurian shale and carbonate rocks in the subsurface of New York, Ohio, Pennsylvania, and West Virginia were analyzed for total organic carbon (TOC) content and Rock-Eval parameters to evaluate whether or not a Silurian total petroleum system exists in the Appalachian basin. A total of 308 samples were collected and analyzed for this investigation. Dark-gray to black shale and argillaceous carbonate intervals in the Salina Group (and equivalent units), Cabot Head Shale, Rochester Shale, Rose Hill Formation, Lockport Dolomite (or Group), and McKenzie Limestone (or Member) were prioritized for sampling and analysis.

  2. Stressed aquifers in the Lower Segura basin and the Vinalopó basin in Easter Spain

    Directory of Open Access Journals (Sweden)

    Andrés Sahuquillo

    2016-01-01

    Full Text Available The carbonate aquifers of the Lower Segura Basin and the Vinalopó basin, along with some other granular aquifers are being exploited well above its average recharge for almost half a century. That causes a continuous decline of groundwater levels in most of the region, up to 5m/year in some cases and more than 300m from their initial situation in some areas, thus increasing the cost of groundwater pumping. The drop in levels produced the drying of springs and wetlands and increased salinity in some areas caused by the presence of saline formations. Against these problems is the increase in wealth created by the availability of water since the beginning of the intense exploitation of aquifers. The Water Framework Directive requires that aquifers being by 2015 in good quantitative and qualitative conditions, which is not possible, and neither would be delaying this date several decades. Simple analyses indicate that even eliminating pumping; groundwater would take between 100 and 1000years to recover. Several methods have been used for determining groundwater recharge and mathematical models that reproduce aquifer’s behaviour and could be used as valid tools for its management. The role that aquifers can play in the water resource management is discussed.

  3. Modelling the Congo basin ecosystems with a dynamic vegetation model

    Science.gov (United States)

    Dury, Marie; Hambuckers, Alain; Trolliet, Franck; Huynen, Marie-Claude; Haineaux, Damien; Fontaine, Corentin M.; Fayolle, Adeline; François, Louis

    2014-05-01

    The scarcity of field observations in some parts of the world makes difficult a deep understanding of some ecosystems such as humid tropical forests in Central Africa. Therefore, modelling tools are interesting alternatives to study those regions even if the lack of data often prevents sharp calibration and validation of the model projections. Dynamic vegetation models (DVMs) are process-based models that simulate shifts in potential vegetation and its associated biogeochemical and hydrological cycles in response to climate. Initially run at the global scale, DVMs can be run at any spatial scale provided that climate and soil data are available. In the framework of the BIOSERF project ("Sustainability of tropical forest biodiversity and services under climate and human pressure"), we use and adapt the CARAIB dynamic vegetation model (Dury et al., iForest - Biogeosciences and Forestry, 4:82-99, 2011) to study the Congo basin vegetation dynamics. The field campaigns have notably allowed the refinement of the vegetation representation from plant functional types (PFTs) to individual species through the collection of parameters such as the specific leaf area or the leaf C:N ratio of common tropical tree species and the location of their present-day occurrences from literature and available database. Here, we test the model ability to reproduce the present spatial and temporal variations of carbon stocks (e.g. biomass, soil carbon) and fluxes (e.g. gross and net primary productivities (GPP and NPP), net ecosystem production (NEP)) as well as the observed distribution of the studied species over the Congo basin. In the lack of abundant and long-term measurements, we compare model results with time series of remote sensing products (e.g. vegetation leaf area index (LAI), GPP and NPP). Several sensitivity tests are presented: we assess consecutively the impacts of the level at which the vegetation is simulated (PFTs or species), the spatial resolution and the initial land

  4. Dynamic reorganization of river basins.

    Science.gov (United States)

    Willett, Sean D; McCoy, Scott W; Perron, J Taylor; Goren, Liran; Chen, Chia-Yu

    2014-03-07

    River networks evolve as migrating drainage divides reshape river basins and change network topology by capture of river channels. We demonstrate that a characteristic metric of river network geometry gauges the horizontal motion of drainage divides. Assessing this metric throughout a landscape maps the dynamic states of entire river networks, revealing diverse conditions: Drainage divides in the Loess Plateau of China appear stationary; the young topography of Taiwan has migrating divides driving adjustment of major basins; and rivers draining the ancient landscape of the southeastern United States are reorganizing in response to escarpment retreat and coastal advance. The ability to measure the dynamic reorganization of river basins presents opportunities to examine landscape-scale interactions among tectonics, erosion, and ecology.

  5. 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

  6. Tethys- and Atlas-related deformations in the Triassic Basin, Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, J.S.; Moore, S.R.; Quarles, A.I. [ARCO International Oil and Gas Company, Plano, TX (United States)

    1995-08-01

    Petroleum provinces of Algeria can be divided into Paleozoic and Mesozoic domains. Paleozoic basins are located on the Gondwanaland paleo-continent where the last significant tectonic episode is ascribed to the Late Paleozoic Hercynian Orogeny. Mesozoic basins are located on the south margin of the Neo-Tethyan seaway. These basins were subject to varying degrees of contractional deformation during the Cenozoic Atlas Orogeny. The Triassic Basin of Algeria is a Tethyan feature located above portions of the Paleozoic Oued M`ya and Ghadames Basins. Paleozoic strata are deeply truncated at the Hercynian Unconformity on a broad arch between the older basins. This is interpreted to reflect rift margin rebound during Carboniferous time. Continental Lower Triassic sediments were deposited in a series of northeast trending basins which opened as the Neo-Tethys basin propagated from east to west between Africa and Europe. Middle Triassic marine transgression from the east resulted in evaporate deposition persisting through the Early Jurassic. Passive margin subsidence associated with carbonate marine deposition continued through the Early Cretaceous. Several zones of coeval wrench deformation cross the Atlas and adjoining regions. In the Triassic Basin, inversion occurred before the end of the Early Cretaceous. This episode created discrete uplifts, where major hydrocarbon accumulations have been discovered, along northeast trending lineaments. During the Eocene, the main phase of the Atlas Orogeny produced low amplitude folding of Jurassic and Cretaceous sediments. The folds detach within the Triassic-Jurassic evaporate interval. Many of these folds have been tested without success, as the deeper reservoirs do not show structural closure.

  7. Hydrologic Sub-basins of Greenland

    Data.gov (United States)

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

  8. Groundwater quality in the Mohawk River Basin, New York, 2011

    Science.gov (United States)

    Nystrom, Elizabeth A.; Scott, Tia-Marie

    2013-01-01

    Water samples were collected from 21 production and domestic wells in the Mohawk River Basin in New York in July 2011 to characterize groundwater quality in the basin. The samples were collected and processed using standard U.S. Geological Survey procedures and were analyzed for 148 physiochemical properties and constituents, including dissolved gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds (VOCs), radionuclides, and indicator bacteria. The Mohawk River Basin covers 3,500 square miles in New York and is underlain by shale, sandstone, carbonate, and crystalline bedrock. The bedrock is overlain by till in much of the basin, but surficial deposits of saturated sand and gravel are present in some areas. Nine of the wells sampled in the Mohawk River Basin are completed in sand and gravel deposits, and 12 are completed in bedrock. Groundwater in the Mohawk River Basin was typically neutral or slightly basic; the water typically was very hard. Bicarbonate, chloride, calcium, and sodium were the major ions with the greatest median concentrations; the dominant nutrient was nitrate. Methane was detected in 15 samples. Strontium, iron, barium, boron, and manganese were the trace elements with the highest median concentrations. Four pesticides, all herbicides or their degradates, were detected in four samples at trace levels; three VOCs, including chloroform and two solvents, were detected in four samples. The greatest radon-222 activity, 2,300 picocuries per liter, was measured in a sample from a bedrock well, but the median radon activity was higher in samples from sand and gravel wells than in samples from bedrock wells. Coliform bacteria were detected in five samples with a maximum of 92 colony-forming units per 100 milliliters. Water quality in the Mohawk River Basin is generally good, but concentrations of some constituents equaled or exceeded current or proposed Federal or New York State drinking-water standards. The standards

  9. 77 FR 45653 - Yakima River Basin Conservation Advisory Group; Yakima River Basin Water Enhancement Project...

    Science.gov (United States)

    2012-08-01

    ... Conservation Advisory Group; Yakima River Basin Water Enhancement Project, Yakima, WA AGENCY: Bureau of... Committee Act, the Yakima River Basin Conservation Advisory Group, Yakima River Basin Water Enhancement... River Basin Water Conservation Program. DATES: The meeting will be held on Tuesday, August 21, 2012...

  10. Cultural Resources Investigations, Cross Basin Channel Realignments, Atchafalaya Basin, Louisiana

    Science.gov (United States)

    1990-12-01

    segment of the Case account as a " fairy tale " (King 1977:19). During the Civil War the Atchafalaya Basin was the site of a brief, Union military campaign...who farms; it does not imply a plantation owner. The value of planters’ properties ranged from $100.00 to $40,000.00. Persons employed in the lumber

  11. The flux and recovery of bioactive substances in the surface sediments of deep basins off southern California

    Energy Technology Data Exchange (ETDEWEB)

    Jahnke, R.A.

    1990-06-11

    Sediment microbial community biomass and activity in Santa Monica Basin, a nearshore basin in the California Continental Borderland, were examined in October 1985, 1986 and 1987, May 1986, April 1987 and January 1990. Millimeter-scale ATP profiles and incubation of intact cores with {sup 3}H-adenine indicated a high-biomass interface microbial population in the low-oxygen central basin, which was absent in samples from the basin slope sediments. A majority of microbial activity and organic matter mineralization occurred in the top cm of sediment. Comparison of measured ATP and total organic carbon profiles suggest that the C:ATP ratio (wt:wt) ranges between 47:1 and 77:1 in central basin interfacial populations, substantially lower than reported for other aquatic environments. Carbon production estimated from DNA synthesis measurements via {sup 3}H-adenine incorporation was compared with TCO{sub 2} fluxes measured by in situ benthic chamber experiments. Within the uncertainty of the C:ATP ratio, an overall microbial carbon assimilation efficiency of 75--90% was indicated. The low C:ATP ratios and high carbon assimilation efficiencies significantly affect estimates of microbial growth and respiration and are substantially different than those often assumed in the literature. These results suggest that without independent knowledge of these ratios, the uncertainty in tracer-derived microbial growth and respiration rates may be larger than previously reported. 66 refs., 8 figs., 3 tabs.

  12. Proterozoic intracontinental basin: The Vindhyan example

    Indian Academy of Sciences (India)

    The Vindhyan basin is a classic example of Proterozoic intracontinental basin that developed in the central part of the Indian shield along with several other basins such as Cuddapah,Chattisgarh,etc.The strata are exposed in three major sectors:Son valley,Bundelkhand and Rajasthan. Substantially thick Vindhyan rocks ...

  13. Implementing Integrated River Basin Management in China

    NARCIS (Netherlands)

    Boekhorst, D.G.J. te; Smits, A.J.M.; Yu, X.; Lifeng, L.; Lei, G.; Zhang, C.

    2010-01-01

    This paper examines the role of the World Wildlife Fund for Nature China as policy entrepreneur in China. It illustrates the ways in which the World Wildlife Fund for Nature is active in promoting integrated river basin management in the Yangtze River basin and how the efforts at basin level are

  14. 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

  15. Great Basin wildlife disease concerns

    Science.gov (United States)

    Russ Mason

    2008-01-01

    In the Great Basin, wildlife diseases have always represented a significant challenge to wildlife managers, agricultural production, and human health and safety. One of the first priorities of the U.S. Department of Agriculture, Division of Fish and Wildlife Services was Congressionally directed action to eradicate vectors for zoonotic disease, particularly rabies, in...

  16. Paleogeographic significance of Upper Triassic basinal succession of the Tamar Valley, northern Julian Alps (Slovenia

    Directory of Open Access Journals (Sweden)

    Gale Luka

    2015-08-01

    Full Text Available The Julian Alps (western Slovenia structurally belong to the eastern Southern Alps. The Upper Triassic succession mostly consists of shallow water platform carbonates of the Dolomia Principale-Dachstein Limestone system and a deep water succession of the Slovenian Basin outcropping in the southern foothills of the Julian Alps. In addition to the Slovenian Basin, a few other intraplatform basins were present, but they remain poorly researched and virtually ignored in the existing paleogeographic reconstructions of the eastern Southern Alps. Herein, we describe a deepening-upward succession from the Tamar Valley (north-western Slovenia, belonging to the Upper Triassic Tarvisio Basin. The lower, Julian-Tuvalian part of the section comprises peritidal to shallow subtidal carbonates (Conzen Dolomite and Portella Dolomite, and an intermediate carbonate-siliciclastic unit, reflecting increased terrigenous input and storm-influenced deposition (Julian-lowermost Tuvalian shallow-water marlstone and marly limestone of the Tor Formation. Above the drowning unconformity at the top of the Portella Dolomite, Tuvalian well-bedded dolomite with claystone intercalations follows (Carnitza Formation. The latter gradually passes into the uppermost Tuvalian–lowermost Rhaetian bedded dolomite with chert and slump breccias, deposited on a slope and/or at the toe-of-slope (Bača Dolomite. Finally, basinal thin-bedded bituminous limestone and marlstone of Rhaetian age follow (Frauenkogel Formation. The upper part of the Frauenkogel Formation contains meter-scale platform-derived limestone blocks, which are signs of platform progradation. The Tarvisio Basin may have extended as far as the present Santo Stefano di Cadore area, representing a notable paleogeographic unit at the western Neotethys margin.

  17. Geologic Assessment of Undiscovered Oil and Gas Resources of the North Cuba Basin, Cuba

    Science.gov (United States)

    Schenk, Christopher J.

    2010-01-01

    Petroleum generation in the North Cuba Basin is primarily the result of thrust loading of Jurassic and Cretaceous source rocks during formation of the North Cuba fold and thrust belt in the Late Cretaceous to Paleogene. The fold and thrust belt formed as Cuban arc-forearc rocks along the leading edge of the Caribbean plate translated northward during the opening of the Yucatan Basin and collided with the passive margin of southern North America in the Paleogene. Petroleum fluids generated during thrust loading migrated vertically into complex structures in the fold and thrust belt, into structures in the foreland basin, and possibly into carbonate reservoirs along the margins of the Yucatan and Bahama carbonate platforms. The U.S. Geological Survey (USGS) defined a Jurassic-Cretaceous Composite Total Petroleum System (TPS) and three assessment units (AU)-North Cuba Fold and Thrust Belt AU, North Cuba Foreland Basin AU, and the North Cuba Platform Margin Carbonate AU-within this TPS based mainly on structure and reservoir type (fig. 1). There is considerable geologic uncertainty as to the extent of petroleum migration that might have occurred within this TPS to form potential petroleum accumulations. Taking this geologic uncertainty into account, especially in the offshore area, the mean volumes of undiscovered resources in the composite TPS of the North Cuba Basin are estimated at (1) 4.6 billion barrels of oil (BBO), with means ranging from an F95 probability of 1 BBO to an F5 probability of 9 BBO; and (2) 8.6 trillion cubic feet of of gas (TCFG), of which 8.6 TCFG is associated with oil fields, and about 1.2 TCFG is in nonassociated gas fields in the North Cuba Foreland Basin AU.

  18. 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...

  19. Ordovician gas exploration breakthrough in the Gucheng lower uplift of the Tarim Basin and its enlightenment

    OpenAIRE

    Zhaoming, Wang; Haijun, Yang; Yingmin, Qi; Yongquan, Chen; Yanlong, Xu

    2014-01-01

    A steady high yield natural gas flow was tapped in the Ordovician strata of Well Gucheng 6 drilled in the Gucheng lower uplift in the Tarim Basin in 2012, marking the discovery of another carbonate gas exploration field after the other two fields in the middle and northern Tarim Basin (the so called Tazhong and Tabei in the industry). The exploration in the Gucheng lower uplift has experienced three stages: the first stage, marine facies clastic exploration from 1995 to 2003, focusing on the ...

  20. Reactive Transport of Nitrate in Northern California Groundwater basins: An Integrated Characterization and Modeling Approach

    Science.gov (United States)

    Esser, B. K.; Moran, J. E.; Hudson, G. B.; Carle, S. F.; McNab, W.; Tompson, A. F.; Moore, K.; Beller, H.; Kane, S.; Eaton, G.

    2003-12-01

    . Geostatistical realizations of Llagas Basin lithology provide a framework for addressing complexity in nitrate flow paths and spatial variation of denitrifying conditions. Particle transport simulations help calibrate the flow field to groundwater age data. Changes in groundwater geochemistry along the flow paths are used to constrain inverse geochemical models that employ redox reactions, carbonate mineral equilibria, and ion exchange mechanisms to attribute nitrate source types, and, in conjunction with excess N2 data, quantify nitrate losses via denitrification.