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Sample records for large sedimentary basins

  1. Relationship between small and large sedimentary basins: the scale spectrum

    SciTech Connect

    Dewey, J.F.; Karner, G.D.; Pitman, W.C.

    1986-07-01

    Realizing that detachments influence lithospheric extension helps us define the fundamental elements responsible for basin formation. In addition to strain rate, crustal thickness, and lithospheric thickness, these factors are (1) stretching distribution within the upper plate of the detachment, (2) stretching distribution within the lower plate, and (3) depth distribution of the detachment(s), where lateral strain must be balanced within the lithosphere during extension. Intracrustal duplex systems may reflect previous compressional events, or they may be produced by upper-crustal flaking in strike-slip regimes. Basin initiation represents a mechanical process (e.g., hanging-wall collapse), whereas subsequent basin development is primarily an isostatic process controlled by the thermal and mechanical properties of the lithosphere. However, subcrustal lithospheric involvement and, hence, heating are minimal until flexure becomes unimportant, which depends on basin wavelength, lithospheric temperature structure, and hence, rigidity. This wavelength or scale dependency may help explain the difference between the abrupt but short-lived subsidence of small basins, such as the Ridge basin of southern California, and the general negative exponential subsidence characteristic of passive continental margins. The rheological implications of depth-dependent stretching, with thermal modification of the lithosphere during extension, ultimately controls lithospheric strength and, hence, the actual rift/breakup configuration. Together, factors 1 and 2 generate rift and thermal subsidences, the final form of which depends on the flexural properties of the lithosphere. The exact relationship between factors 1 and 2 determines the spatial configuration between rift and sag basins and temporary uplifts. They illustrate these concepts and their implications with examples from California, Nevada, Brazil, Turkey, and Australia.

  2. South American sedimentary basins

    SciTech Connect

    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.

  3. Evolution of sedimentary basins

    SciTech Connect

    Hellinger, S.J.

    1983-03-01

    Simple extensional models that involve stretching by listric faulting in the brittle upper crust and plastic flow in the lower lithosphere have been shown to account for the subsidence history of various sedimentary basins, continental shelves, and the Central graben in the North Sea. In this paper, the authors present a simplified analysis of the two-layer extensional model for the elementary case in which extension is instantaneous, the crust is thinned by a different amount from the subcrustal lithosphere, the effects of radioactivity and dike intrusion are ignored, and local isostatic compensation is assumed at all times. The authors show how the thinning parameters can be obtained from the subsidence data through the use of a simple and powerful method of data analysis. The authors show that conservation of mass during a process of non-uniform extension implies that much greater thicknesses of sediment can be deposited in a young basin than in the case of uniform extension of both crust and subcrustal lithosphere. Further, the authors show that such an extensional process produces significant uplift of the flanks of a graben and that, as a result of erosion of the uplifted areas, the effective area of the basin can be increased as much as 25 to 30%, depending on the rate of erosion, compared to the area that would have been created by a process of uniform extension. Finally, the authors consider the forces of uplift on the flanks in the situation where the crust is treated as a thin elastic plate floating on a fluid upper mantle, the graben is bounded by two major normal faults, and there is subcrustal thinning under the flanks. The authors show that such normal faults produce uplift of the flanks and that this uplift can be significantly increased by the subcrustal thinning.

  4. Geochemical Aspects of Formation of Large Oil Deposits in the Volga-Ural Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Plotnikova, I.; Nosova, F.; Pronin, N.; Nosova, J.; Budkevich, T.

    2012-04-01

    The study of the rocks domanikoid type in the territory of the Ural-Volga region has an almost century-long history, beginning with the first studies of A.D. Archangelsky in the late 20's of last century. But nevertheless the question of the source of oil that formed the industrial deposits of Volga-Ural oil and gas province (OGP), where Romashkinskoye oil field occupies a special place, remains unresolved and topical. According to the sedimentary-migration theory of origin of oil and gas, it is supposed that the primary source of hydrocarbons in this area are the deposits of domanikoid type that contain a large ammount of sapropel organic matter (OM). Semiluki (domanik) horizon of srednefranski substage of the Upper Devonian is considered to be a typical domanikoid stratum. Investigation of the OM of the rocks and oils of the sedimentary cover on the basis of chromato-mass spectrometry method allows us to study the correlations between rock and oil and to assess the location (or absence) of the sources of hydrocarbons in the Paleozoic sedimentary cover. The results of geochemical study of dispersed organic matter (DOM) of rocks from Semiluksky horizon of the Upper Devonian and of the oil from Pashiysky horizon of the Middle Devonian form the basis of this paper. The objectives of this study were the following: to determine the original organic matter of the rocks, which would indicate the conditions of sedimentation of the supposed rock-oil sources; the study of chemofossils (biomarkers) in oil from Pashiyskiy horizon; and the identification of genetic association of DOM rocks from Semiluksky horizon with this oil on the basis of the oil-DOM correlation. The study of biomarkers was carried out with the help of chromato-mass spectrometry in the Laboratory of Geochemistry of Fossil Fuels (Kazan Federal University). In this study we used several informative parameters characterizing the depositional environment, the type of source OM and its maturity: STER / PENT, h

  5. Morphology, sedimentary features and evolution of a large palaeo submarine canyon in Qiongdongnan basin, Northern South China Sea

    NASA Astrophysics Data System (ADS)

    Li, Xiangquan; Fairweather, Luke; Wu, Shiguo; Ren, Jianye; Zhang, Hongjie; Quan, Xiayun; Jiang, Tao; Zhang, Cheng; Su, Ming; He, Yunlong; Wang, Dawei

    2013-01-01

    The large Miocene-aged palaeo canyon that extents through the Qiongdongnan basin (QDNB) and Yinggehai basin (YGHB) of Northern South China Sea has been of considerable interest both economically and scientifically over the past decade. Stemmed from this, significant research has been employed into understanding the mechanism for its existence, incision, and sedimentary fill, yet debate remains. In the first case the canyon itself is actually quite anomalous. Alone from the size (over 570 km in length and more than 8 km in width (Yuan et al., 2009)), which is considerably more than most ancient deep-water channels (REFS), the canyon's sedimentary fill is also distinctly different. Some explanations have been given to explain the canyon's origin and existence, these include increased sediment supply from the Red River which is genetically linked to uplift of the Tibetan Plateau, lowstand turbidite and mass-transport activity, reactivation and dextral displacement of the Red River Fault zone inducing erosive gravity-flows, regional tilt of the QDNB and YGHB, paleo-seafloor morphology and seal-level fluctuations. With the application of new data obtained from interpretations of a large number of 2D seismic profiles, core and well log data, and tectonic and sedimentary analysis this contribution aims to: (1) Present models to explain the Canyon's sedimentary fill and basin plain deposits, which provided significant understanding of processes pre-, syn- and post-incision and; (2) review the plausibility and likelihood of each of the controlling mechanisms, hoping to shed light on this controversial aspect. We conclude that the final erosive event that shaped the canyon is dated at 5.5 Ma. The Canyon's unusual fill is a product of variation in the interaction between turbidity currents and MTD that blocked the canyon's axis, and the reduction in gravity flow energy through time; and therefore the complete succession represents one major erosive and cut event at 5.5 Ma and

  6. Large-Scale Multiphase Flow Modeling of Hydrocarbon Migration and Fluid Sequestration in Faulted Cenozoic Sedimentary Basins, Southern California

    NASA Astrophysics Data System (ADS)

    Jung, B.; Garven, G.; Boles, J. R.

    2011-12-01

    Major fault systems play a first-order role in controlling fluid migration in the Earth's crust, and also in the genesis/preservation of hydrocarbon reservoirs in young sedimentary basins undergoing deformation, and therefore understanding the geohydrology of faults is essential for the successful exploration of energy resources. For actively deforming systems like the Santa Barbara Basin and Los Angeles Basin, we have found it useful to develop computational geohydrologic models to study the various coupled and nonlinear processes affecting multiphase fluid migration, including relative permeability, anisotropy, heterogeneity, capillarity, pore pressure, and phase saturation that affect hydrocarbon mobility within fault systems and to search the possible hydrogeologic conditions that enable the natural sequestration of prolific hydrocarbon reservoirs in these young basins. Subsurface geology, reservoir data (fluid pressure-temperature-chemistry), structural reconstructions, and seismic profiles provide important constraints for model geometry and parameter testing, and provide critical insight on how large-scale faults and aquifer networks influence the distribution and the hydrodynamics of liquid and gas-phase hydrocarbon migration. For example, pore pressure changes at a methane seepage site on the seafloor have been carefully analyzed to estimate large-scale fault permeability, which helps to constrain basin-scale natural gas migration models for the Santa Barbara Basin. We have developed our own 2-D multiphase finite element/finite IMPES numerical model, and successfully modeled hydrocarbon gas/liquid movement for intensely faulted and heterogeneous basin profiles of the Los Angeles Basin. Our simulations suggest that hydrocarbon reservoirs that are today aligned with the Newport-Inglewood Fault Zone were formed by massive hydrocarbon flows from deeply buried source beds in the central synclinal region during post-Miocene time. Fault permeability, capillarity

  7. Petroleum potential of the Libyan sedimentary basins

    SciTech Connect

    Hammuda, O.S.; Sbeta, A.M.

    1988-08-01

    Contrary to prevailing opinion, all Libyan sedimentary basins and the Al-Jabal Al-Akhdar platform contain prolific petroleum accumulations with very high prospectivity. A systematic review of the types of traps and pays in this central part of the southern Mediterranean province reveals great variability in reservoir and source rock characteristics. The reservoir rocks are of almost all geologic ages. The thick source rock sequences also vary in nature and organic content. The organic-rich facies have accumulated in intracratonic and passive margin basins or in marginal seas. Most of the oil discovered thus far in these basins is found in large structural traps. Future discoveries of stratigraphic traps or small structural traps will require intensified efforts and detailed studies using up-to-date multidisciplinary techniques in sedimentary tectonics, biostratigraphic facies analysis, and geochemical prospecting in order to develop a better understanding of these basins, thus improving their prospectivity.

  8. Inversion of Extensional Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    Buiter, Susanne J. H.; Pfiffner, O. Adrian

    The evolution of extensional sedimentary basins is governed by the surrounding stress field and can, therefore, be expected to be highly sensitive to variations in these stresses. Important changes in basin geometry are to be expected in the case of an even short-lived reversal from extension to compression. We investigate the evolu- tion of fold and thrust structures which form in compression after extension, when basin forming processes have come to a complete stop. To this purpose, we use a two- dimensional, viscoplastic model and start our experiments from a pre-existing exten- sional geometry. We illustrate the sensitivity of the evolving structures to inherited extensional geometry, sedimentary and erosional processes, and material properties. One series of our model experiments involves the upper- to middle crust only in order to achieve a high detail in the basin area. We find that our results agree with examples from nature and analogue studies in, among others, the uplift and rotation of syn-rift sediments, the propagation of shear zones into the post-rift sediments and, in specific cases, the development of back-thrusts or basement short-cut faults. We test the out- come of these models by performing a second series of model simulations in which basins on a continental margin are inverted through their progressive approach of a subduction zone. These latter models are on the scale of the whole upper mantle.

  9. Geothermal resources of California sedimentary basins

    USGS Publications Warehouse

    Williams, C.F.; Grubb, F.V.; Galanis, S.P.

    2004-01-01

    The 2004 Department of Energy (DOE) Strategic Plan for geothermal energy calls for expanding the geothermal resource base of the United States to 40,000 MW of electric power generating potential. This will require advances in technologies for exploiting unconventional geothermal resources, including Enhanced Geothermal Systems (EGS) and geopressured geothermal. An investigation of thermal conditions in California sedimentary basins through new temperature and heat flow measurements reveals significant geothermal potential in some areas. In many of the basins, the combined cooling effects of recent tectonic and sedimentary processes result in relatively low (<60 mW/m2) heat flow and geothermal gradients. For example, temperatures in the upper 3 km of San Joaquin, Sacramento and Ventura basins are typically less than 125??C and do not reach 200??c by 5 km. By contrast, in the Cuyama, Santa Maria and western Los Angeles basins, heat flow exceeds 80 mW/m2 and temperatures near or above 200??C occur at 4 to 5 km depth, which represents thermal conditions equivalent to or hotter than those encountered at the Soultz EGS geothermal site in Europe. Although the extractable geothermal energy contained in these basins is not large relative to the major California producing geothermal fields at The Geysers or Salton Sea, the collocation in the Los Angeles basin of a substantial petroleum extraction infrastructure and a major metropolitan area may make it attractive for eventual geothermal development as EGS technology matures.

  10. Three-dimensional simulations of ground motions in sedimentary basins

    USGS Publications Warehouse

    Frankel, Arthur

    1993-01-01

    This report describes work being done at the U.S. Geological Survey on 3-D simulations of earthquake ground motions in sedimentary basins. The ultimate goal of this research is to predict strong ground motions in sedimentary basins for expected large earthquakes. This report emphasizes the inadequacy of using flat-layered models for synthesizing ground motions in sedimentary basins. 2-D and 3-D simulations have demonstrated how the slope of the alluvium-bedrock interface can trap S-waves in the basins, producing prolonged surface wave trains. These large surface waves are not generated in 1-D flat layered models, which underestimate the duration and peak amplitude of shaking. We present results of 3-D simulations for the San Bernardino and Santa Clara valleys, California, for earthquakes on the San Andreas fault.

  11. African sedimentary basins - Tectonic controls on prospectivity

    SciTech Connect

    Bunter, M.A.G.; Crossley, R.; Hammill, M.; Jones, P.W.; Morgan, R.K.; Needham, D.T.; Spaargaren, F.A. )

    1991-03-01

    An important prerequisite for the evaluation of any sedimentary basin is the understanding of its regional tectonic setting. This is especially so in the underexplored regions of Africa. The majority of African sedimentary basins developed in an extensional setting although some have undergone subsequent compressional or transpressional deformation. The geometry and evolution of these basins is often influenced by basement structure. The extensional phase of basin development controls not only the distribution of syn-rift sediments but also the magnitude of post-rift regional subsidence and the preservation or removal of pre-rift sediments. This has important consequences for exploration models of syn-rift and pre-rift source rocks and reservoirs. Post-rift basin inversion and uplift provide crucial controls on the preservation of mature source rocks and quality of reservoirs. The distribution, nature, timing, and possible mechanisms of this uplift in Africa will be addressed. The hydrocarbon prospectivity of African basis appears to be highly variable although the limited exploration of some regions makes the exact extent of this variability unclear. Basins considered potentially prospective range from late Precambrian to Tertiary in age. The various tectonic controls outlined above, and criteria for the evaluation of underexplored areas, will be demonstrated by reference to basins studied by The Robertson Group. Examples described include basins from Bagon, Angola, Namibia, East Africa, Tertiary Rift and Karoo Rifts, and North Africa (Sudan, Egypt, Algeria, and Morocco).

  12. Thermal evolution of sedimentary basins in Alaska

    USGS Publications Warehouse

    Johnsson, Mark J.; Howell, D.G.

    1996-01-01

    The complex tectonic collage of Alaska is reflected in the conjunction of rocks of widely varying thermal maturity. Indicators of the level of thermal maturity of rocks exposed at the surface, such as vitrinite reflectance and conodont color alteration index, can help constrain the tectonic evolution of such complex regions and, when combined with petrographic, modern heat flow, thermogeochronologic, and isotopic data, allow for the detailed evaluation of a region?s burial and uplift history. We have collected and assembled nearly 10,000 vitrinite-reflectance and conodont-color-alteration index values from the literature, previous U.S. Geological Survey investigations, and our own studies in Alaska. This database allows for the first synthesis of thermal maturity on a broadly regional scale. Post-accretionary sedimentary basins in Alaska show wide variability in terms of thermal maturity. The Tertiary interior basins, as well as some of the forearc and backarc basins associated with the Aleutian Arc, are presently at their greatest depth of burial, with immature rocks exposed at the surface. Other basins, such as some backarc basins on the Alaska Peninsula, show higher thermal maturities, indicating modest uplift, perhaps in conjunction with higher geothermal gradients related to the arc itself. Cretaceous ?flysch? basins, such as the Yukon-Koyukuk basin, are at much higher thermal maturity, reflecting great amounts of uplift perhaps associated with compressional regimes generated through terrane accretion. Many sedimentary basins in Alaska, such as the Yukon-Koyukuk and Colville basins, show higher thermal maturity at basin margins, perhaps reflecting greater uplift of the margins in response to isostatic unloading, owing to erosion of the hinterland adjacent to the basin or to compressional stresses adjacent to basin margins.

  13. Prediction of hydrocarbons in sedimentary basins

    USGS Publications Warehouse

    Harff, J.E.; Davis, J.C.; Eiserbeck, W.

    1993-01-01

    To estimate the undiscovered hydrocarbon potential of sedimentary basins, quantitative play assessments specific for each location in a region may be obtained using geostatistical methods combined with the theory of classification of geological objects, a methodology referred to as regionalization. The technique relies on process modeling and measured borehole data as well as probabilistic methods to exploit the relationship between geology (the "predictor") and known hydrocarbon productivity (the "target") to define prospective stratigraphic intervals within a basin. It is demonstrated in case studies from the oil-producing region of the western Kansas Pennsylvanian Shelf and the gas-bearing Rotliegend sediments of the Northeast German Basin. ?? 1993 International Association for Mathematical Geology.

  14. Sedimentary facies and evolution of large sandbody of the upper part of Huagang Formation in Xihu Sag, East China Sea Basin, China

    NASA Astrophysics Data System (ADS)

    Zhao, Shuai; Chen, Lin

    2017-04-01

    Xihu sag is one of the largest subprime unit of the east China sea basin. In recent years, with the discovery of some large-scale gas fields in the Huanggang Formation of Xihu Sag, the sedimentary facies and gas exploration of Huanggang Formation have become a hotspot of many domestic and overseas petroleum geologists study. This research mainly focused on the upper part of Huagang Formation which was composed by a set of large scale sandbodies in Xihu sag. Based on the application of sequence stratigraphy, sedimentology, and seismic sedimentology, this paper has studied the sedimentary facies and evolution of the upper part of Huagang Formation in Xihu Sag. The geophysical technologies, including seismic attributes, constrained sparse pulse inversion and post-stack geostatistical inversion, are also used to characterize the sandbodies' development features and spatial distribution of the upper part of Huagang Formation. Our results show that braided river is the main facies of the upper part in the Huagang Formation and The Huanggang Formation primary can be divided into lowstand systems tract (LST) and transgressive systems tract (TST). The upstream of the braided river is characterized by thick sandstone and narrow channel. The sandbody displays a better lateral continuity and the channel become wider from upstream to downstream. As the erosion of the incised channel weakened, the sandstone thickness tends to be thinner. Conglomerates can also be occasionally observed at the bottom of thick superimposed sandbodies. On both sides of the braided river, thin sandstone layers are developed. There are also visible of lateral migration of the sandbodies of the downstream. Lithology profiles also illustrate that the sandbodies display poor lateral continuity on the both sides of the braided river .Sedimentary evolution analysis showing that the braided channels are mainly developed in the LST of Lower Huagang Formation from the NNE axial to basin. During TST, the

  15. Thermal regimes of Malaysian sedimentary basins

    SciTech Connect

    Abdul Halim, M.F. )

    1994-07-01

    Properly corrected and calibrated thermal data are important in estimating source-rock maturation, diagenetics, evolution of reservoirs, pressure regimes, and hydrodynamics. Geothermal gradient, thermal conductivity, and heat flow have been determined for the sedimentary succession penetrated by exploratory wells in Malaysia. Geothermal gradient and heat-flow maps show that the highest average values are in the Malay Basin. The values in the Sarawak basin are intermediate between those of the Malay basin and the Sabah Basin, which contains the lowest average values. Temperature data were analyzed from more than 400 wells. An important parameter that was studied in detail is the circulation time. The correct circulation time is essential in determining the correct geothermal gradient of a well. It was found that the most suitable circulation time for the Sabah Basin is 20 hr, 30 hr for the Sarawak Basin and 40 hr for the Malay Basin. Values of thermal conductivity, determined from measurement and calibrated calculations, were grouped according to depositional units and cycles in each basin.

  16. NATURAL GAS RESOURCES IN DEEP SEDIMENTARY BASINS

    SciTech Connect

    Thaddeus S. Dyman; Troy Cook; Robert A. Crovelli; Allison A. Henry; Timothy C. Hester; Ronald C. Johnson; Michael D. Lewan; Vito F. Nuccio; James W. Schmoker; Dennis B. Riggin; Christopher J. Schenk

    2002-02-05

    From a geological perspective, deep natural gas resources are generally defined as resources occurring in reservoirs at or below 15,000 feet, whereas ultra-deep gas occurs below 25,000 feet. From an operational point of view, ''deep'' is often thought of in a relative sense based on the geologic and engineering knowledge of gas (and oil) resources in a particular area. Deep gas can be found in either conventionally-trapped or unconventional basin-center accumulations that are essentially large single fields having spatial dimensions often exceeding those of conventional fields. Exploration for deep conventional and unconventional basin-center natural gas resources deserves special attention because these resources are widespread and occur in diverse geologic environments. In 1995, the U.S. Geological Survey estimated that 939 TCF of technically recoverable natural gas remained to be discovered or was part of reserve appreciation from known fields in the onshore areas and State waters of the United. Of this USGS resource, nearly 114 trillion cubic feet (Tcf) of technically-recoverable gas remains to be discovered from deep sedimentary basins. Worldwide estimates of deep gas are also high. The U.S. Geological Survey World Petroleum Assessment 2000 Project recently estimated a world mean undiscovered conventional gas resource outside the U.S. of 844 Tcf below 4.5 km (about 15,000 feet). Less is known about the origins of deep gas than about the origins of gas at shallower depths because fewer wells have been drilled into the deeper portions of many basins. Some of the many factors contributing to the origin of deep gas include the thermal stability of methane, the role of water and non-hydrocarbon gases in natural gas generation, porosity loss with increasing thermal maturity, the kinetics of deep gas generation, thermal cracking of oil to gas, and source rock potential based on thermal maturity and kerogen type. Recent experimental simulations using laboratory

  17. Physical Modelling of Sedimentary Basin

    SciTech Connect

    Yuen, David A.

    2003-04-24

    The main goals of the first three years have been achieved, i.e., the development of particle-based and continuum-based algorithms for cross-scaleup-scale analysis of complex fluid flows. The U. Minnesota team has focused on particle-based methods, wavelets (Rustad et al., 2001) and visualization and has had great success with the dissipative and fluid particle dynamics algorithms, as applied to colloidal, polymeric and biological systems, wavelet filtering and visualization endeavors. We have organized two sessions in nonlinear geophysics at the A.G.U. Fall Meeting (2000,2002), which have indeed synergetically stimulated the community and promoted cross-disciplinary efforts in the geosciences. The LANL team has succeeded with continuum-based algorithms, in particular, fractal interpolating functions (fif). These have been applied to 1-D flow and transport equations (Travis, 2000; 2002) as a proof of principle, providing solutions that capture dynamics at all scales. In addition, the fif representations can be integrated to provide sub-grid-scale homogenization, which can be used in more traditional finite difference or finite element solutions of porous flow and transport. Another useful tool for fluid flow problems is the ability to solve inverse problems, that is, given present-time observations of a fluid flow, what was the initial state of that fluid system? We have demonstrated this capability for a large-scale problem of 3-D flow in the Earth's crust (Bunge, Hagelberg & Travis, 2002). Use of the adjoint method for sensitivity analysis (Marchuk, 1995) to compute derivatives of models makes the large-scale inversion feasible in 4-D, , space and time. Further, a framework for simulating complex fluid flow in the Earth's crust has been implemented (Dutrow et al, 2001). The remaining task of the first three-year campaign is to extend the implementation of the fif formalism to our 2-D and 3-D computer codes, which is straightforward, but involved.

  18. Precambrian shield and basement tectonics in sedimentary basin analysis

    SciTech Connect

    Touborg, J.F.

    1984-04-01

    This study focused on the use of (1) regional structural analysis of basement and Precambrian rocks surrounding a sedimentary basin, and (2) tracing basement structures into the sedimentary basin. The structural analysis of the Precambrian shield has a fundamental bearing on interpretation of overlying sedimentary cover rocks. This is expressed in the southern part of the Hudson's Bay basin and its southeastern arm, the Moose River basin. For instance, the rims of both basins are controlled by faults or graben structures. Approximately 13 major fault systems with strike lengths of 200-300 km (125-186 mi) or more can be traced from the exposed Precambrian shield into the basin in terms of lineament arrays and/or aeromagnetic and/or gravity signature. The data suggest reactivation of faults during basin sedimentation. This type of basement structural analysis in areas adjacent to sedimentary basins can provide a valuable interpretation base for subsequent seismic surveys and basin evaluation.

  19. Magnetic fabrics in tectonically inverted sedimentary basins: a review

    NASA Astrophysics Data System (ADS)

    García-Lasanta, Cristina; Román-Berdiel, Teresa; Casas-Sainz, Antonio; Oliva-Urcia, Belén; Soto, Ruth; Izquierdo-Llavall, Esther

    2017-04-01

    Magnetic fabric studies in sedimentary rocks were firstly focused on strongly deformed tectonic contexts, such as fold-and-thrust belts. As measurement techniques were improved by the introduction of high-resolution equipments (e.g. KLY3-S and more recent Kappabridge susceptometers from AGICO Inc., Czech Republic), more complex tectonic contexts could be subjected to anisotropy of magnetic susceptibility (AMS) analyses in order to describe the relationship between tectonic conditions and the orientation and shape of the resultant magnetic ellipsoids. One of the most common complex tectonic frames involving deformed sedimentary rocks are inverted extensional basins. In the last decade, multiple AMS studies revealed that the magnetic fabric associated with the extensional stage (i.e. a primary magnetic fabric) can be preserved despite the occurrence of subsequent deformational processes. In these cases, magnetic fabrics may provide valuable information about the geometry and kinematics of the extensional episode (i.e. magnetic ellipsoids with their minimum susceptibility axis oriented perpendicular to the deposit plane and magnetic lineation oriented parallel to the extension direction). On the other hand, several of these studies have also determined how the subsequent compressional stage can modify the primary extensional fabric in some cases, particularly in areas subjected to more intense deformation (with development of compression-related cleavage). In this contribution we present a compilation of AMS studies developed in sedimentary basins that underwent different degree of tectonic inversion during their history, in order to describe the relationship of this degree of deformation and the degree of imprint that tectonic conditions have in the previous magnetic ellipsoid (primary extension-related geometry). The inverted basins included in this synthesis are located in the Iberian Peninsula and show: i) weak deformation (W Castilian Branch and Maestrazgo basin

  20. Development of the Mozambique and Ruvuma sedimentary basins, offshore Mozambique

    NASA Astrophysics Data System (ADS)

    Salman, G.; Abdula, I.

    1995-04-01

    Two major sedimentary basins have been identified on the continental margin of Mozambique—Mozambique Basin and Ruvuma Basin. The formation of the basins is related to the break-up of Gondwana and opening of the western part of the Indian Ocean. The basins are relatively young, having developed discordantly to the structural plan of Gondwana sedimentary basins. The history of the formation of the East African continental margin sedimentary basins within Mozambique has been studied on the basis of the present-day concept of Gondwana break-up and Madagascar's drift with respect to Africa. Two stages in the history of the East African basins can be recognized: late-Gondwana and post-Gondwana. The late-Gondwana stage (303-157 Ma) is typified by sedimentary and volcanogenic rocks of the Karoo Group. The post-Gondwana stage (157-0 Ma) corresponds to the period of active Gondwana break-up and the formation of Indian Ocean marginal basins. The Mozambique Basin occupies both central and southern parts of the coastal plain of Mozambique, extending onto the continental shelf and slope. The sedimentary fill is composed of Upper Jurassic, Cretaceous and Cenozoic rocks which discordantly overly the Karoo basalts. The Upper Jurassic occurs as continental red-beds, mostly distributed within buried grabens. Cretaceous rocks occur as terrigenous sediments of continental and marine genesis. Cenozoic deposits are of predominantly marine and deltaic origin. The Ruvuma Basin, situated in the north of Mozambique, is part of an extended East African marginal basin which includes parts of the coastal plains and continental margins of Tanzania and Kenya. The basement of the basin is composed of crystalline and metamorphic rocks of pre-Cambrian age. The sedimentary fill is represented by continental terrigenous Karoo sediments, marine and lagoonal Jurassic deposits, and marine and deltaic rocks of Cretaceous and Cenozoic age. The main difference between the sedimentary fill of the

  1. Early Archaean crustal collapse structures and sedimentary basin dynamics

    NASA Astrophysics Data System (ADS)

    Nijman, W.; de Vries, S. T.

    2003-04-01

    Observations in the Lower Archaean (>3.3 Ga) of the Pilbara and Kaapvaal Cratons point to a direct genetic relationship between the thickness and facies distribution of volcano-sedimentary basin fills and non-linear patterns of extensional faults in early Earth. The basin fills consist of mafic volcanic products, largely pillow basalts, with distinct phases of intermediate to felsic volcanism and concentration of silica, either primary or secondary, in sediments deposited near base-level. The extensional structures are listric growth-faults, arranged in superposed arrays, that migrated upwards with the growth of the Early Archaean stratigraphical column. The faults linked intermittently occurring shallow-level felsic intrusions via porphyry pipes, veins and hydrothermal circulations with the surficial sedimentary basin fill of cherty sediments, concurrent mineralisation and alteration products. The non-linear pattern of the fault systems is recorded by their restored facing directions over large areas and corresponds best with over 100 km-wide (semi)circular crustal collapse structures. Crustal collapse, and therefore basin formation, did not represent a reaction to compression and crustal thickening. It also had no relationship with the present-day distribution of granitoid domes and greenstone belts. Collapse followed crustal uplift recorded by shallowing of the basin fill from a general subaqueous level of deposition of pillow basalts towards zero water level for the sediments and low-relief emersion. Maxima of extension coincide with the appearance of intermediate or felsic volcanic rocks in the overall mafic environment. The geodynamical setting is most appropriately explained by crustal delamination and related plume activity. Although individual features may be compared to Phanerozoic and Recent geological phenomena, like calderas, for the collapse structures as a whole such younger counterparts cannot be found. Rather they have their equivalents in collapse

  2. Mongolian Oil Shale, hosted in Mesozoic Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    Bat-Orshikh, E.; Lee, I.; Norov, B.; Batsaikhan, M.

    2016-12-01

    Mongolia contains several Mesozoic sedimentary basins, which filled >2000 m thick non-marine successions. Late Triassic-Middle Jurassic foreland basins were formed under compression tectonic conditions, whereas Late Jurassic-Early Cretaceous rift valleys were formed through extension tectonics. Also, large areas of China were affected by these tectonic events. The sedimentary basins in China host prolific petroleum and oil shale resources. Similarly, Mongolian basins contain hundreds meter thick oil shale as well as oil fields. However, petroleum system and oil shale geology of Mongolia remain not well known due to lack of survey. Mongolian oil shale deposits and occurrences, hosted in Middle Jurassic and Lower Cretaceous units, are classified into thirteen oil shale-bearing basins, of which oil shale resources were estimated to be 787 Bt. Jurassic oil shale has been identified in central Mongolia, while Lower Cretaceous oil shale is distributed in eastern Mongolia. Lithologically, Jurassic and Cretaceous oil shale-bearing units (up to 700 m thick) are similar, composed mainly of alternating beds of oil shale, dolomotic marl, siltstone and sandstone, representing lacustrine facies. Both Jurassic and Cretaceous oil shales are characterized by Type I kerogen with high TOC contents, up to 35.6% and low sulfur contents ranging from 0.1% to 1.5%. Moreover, S2 values of oil shales are up to 146 kg/t. The numbers indicate that the oil shales are high quality, oil prone source rocks. The Tmax values of samples range from 410 to 447, suggesting immature to early oil window maturity levels. PI values are consistent with this interpretation, ranging from 0.01 to 0.03. According to bulk geochemistry data, Jurassic and Cretaceous oil shales are identical, high quality petroleum source rocks. However, previous studies indicate that known oil fields in Eastern Mongolia were originated from Lower Cretaceous oil shales. Thus, further detailed studies on Jurassic oil shale and its

  3. Geofluid Dynamics of Faulted Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    Garven, G.; Jung, B.; Boles, J. R.

    2014-12-01

    Faults are known to affect basin-scale groundwater flow, and exert a profound control on petroleum migration/accumulation, the PVT-history of hydrothermal fluids, and the natural (submarine) seepage from offshore reservoirs. For example, in the Santa Barbara basin, measured gas flow data from a natural submarine seep area in the Santa Barbara Channel helps constrain fault permeability k ~ 30 millidarcys for the large-scale upward migration of methane-bearing formation fluids along one of the major fault zones. At another offshore site near Platform Holly, pressure-transducer time-series data from a 1.5 km deep exploration well in the South Ellwood Field demonstrate a strong ocean tidal component, due to vertical fault connectivity to the seafloor. Analytical solutions to the poroelastic flow equation can be used to extract both fault permeability and compressibility parameters, based on tidal-signal amplitude attenuation and phase shift at depth. These data have proven useful in constraining coupled hydrogeologic 2-D models for reactive flow and geomechanical deformation. In a similar vein, our studies of faults in the Los Angeles basin, suggest an important role for the natural retention of fluids along the Newport-Inglewood fault zone. Based on the estimates of fault permeability derived above, we have also constructed new two-dimensional numerical simulations to characterize large-scale multiphase flow in complex heterogeneous and anisotropic geologic profiles, such as the Los Angeles basin. The numerical model was developed in our lab at Tufts from scratch, and based on an IMPES-type algorithm for a finite element/volume mesh. This numerical approach allowed us model large differentials in fluid saturation and relative permeability, caused by complex geological heterogeneities associated with sedimentation and faulting. Our two-phase flow models also replicated the formation-scale patterns of petroleum accumulation associated with the basin margin, where deep

  4. Hydrogeologic framework of sedimentary deposits in six structural basins, Yakima River basin, Washington

    USGS Publications Warehouse

    Jones, M.A.; Vaccaro, J.J.; Watkins, A.M.

    2006-01-01

    The hydrogeologic framework was delineated for the ground-water flow system of the sedimentary deposits in six structural basins in the Yakima River Basin, Washington. The six basins delineated, from north to south are: Roslyn, Kittitas, Selah, Yakima, Toppenish, and Benton. Extent and thicknesses of the hydrogeologic units and total basin sediment thickness were mapped for each basin. Interpretations were based on information from about 4,700 well records using geochemical, geophysical, geologist's or driller's logs, and from the surficial geology and previously constructed maps and well interpretations. The sedimentary deposits were thickest in the Kittitas Basin reaching a depth of greater than 2,000 ft, followed by successively thinner sedimentary deposits in the Selah basin with about 1,900 ft, Yakima Basin with about 1,800 ft, Toppenish Basin with about 1,200 ft, Benton basin with about 870 ft and Roslyn Basin with about 700 ft.

  5. Tectonic framework of Turkish sedimentary basins

    SciTech Connect

    Yilmaz, P.O. )

    1988-08-01

    Turkey's exploration potential primarily exists in seven onshore (Southeast Turkey platform, Tauride platform, Pontide platform, East Anatolian platform, Interior, Trace, and Adana) basins and four offshore (Black Sea, Marmara Sea, Aegean Sea, and Mediterranean Sea) regional basins formed during the Mesozoic and Tertiary. The Mesozoic basins are the onshore basins: Southeast Turkey, Tauride, Pontide, East Anatolian, and Interior basins. Due to their common tectonic heritage, the southeast Turkey and Tauride basins have similar source rocks, structural growth, trap size, and structural styles. In the north, another Mesozoic basin, the Pontide platform, has a much more complex history and very little in common with the southerly basins. The Pontide has two distinct parts; the west has Paleozoic continental basement and the east is underlain by island-arc basement of Jurassic age. The plays are in the upper Mesozoic rocks in the west Pontide. The remaining Mesozoic basins of the onshore Interior and East Anatolian basins are poorly known and very complex. Their source, reservoir, and seal are not clearly defined. The basins formed during several orogenic phases in mesozoic and Tertiary. The Cenozoic basins are the onshore Thrace and Adana basins, and all offshore regional basins formed during Miocene extension. Further complicating the onshore basins evolution is the superposition of Cenozoic basins and Mesozoic basins. The Thrace basin in the northwest and Adana basin in the south both originate from Tertiary extension over Tethyan basement and result in a similar source, reservoir, and seal. Local strike-slip movement along the North Anatolian fault modifies the Thrace basin structures, influencing its hydrocarbon potential.

  6. Sedimentary complexes of the cover of the Dzabkhan continental block: Different sedimentary basins and source areas

    NASA Astrophysics Data System (ADS)

    Letnikova, E. F.; Vishnevskaya, I. A.; Letnikov, F. A.; Vetrova, N. I.; Shkolnik, S. I.; Kostitsyn, Yu. A.; Karakovskii, E. A.; Reznitskii, L. Z.; Kanygina, N. A.

    2016-10-01

    The geochemical and Sm-Nd isotope characteristics of Late Precambrian and Early Cambrian sandstones previously related to the sedimentary cover of the Dzabkhan continental block are reported. It is established that the Riphean and Vendian sedimentary rocks of the Ul'zitgol'skaya and Tsaganolomskaya Formations were accumulated within the Dzabkhan continental block as a result of recycling of the terrigenous deposits formed at the expense of destruction of basement rocks and younger granite. The formation of terrigenous rocks of the Bayangol'skaya Formation after a gap in sedimentation occurred in the sedimentary basin, where only the Late Riphean formations of the juvenile crust, probably of the Dzabkhan-Mandal block were the sources, without the contribution of the ancient crustal material. The Tsaganolomskaya and Bayangol'skaya Formations were formed in different sedimentary basins and cannot be related to the same complex.

  7. Preliminary catalog of the sedimentary basins of the United States

    USGS Publications Warehouse

    Coleman, James L.; Cahan, Steven M.

    2012-01-01

    One hundred forty-four sedimentary basins (or groups of basins) in the United States (both onshore and offshore) are identified, located, and briefly described as part of a Geographic Information System (GIS) data base in support of the Geologic Carbon Dioxide Sequestration National Assessment Project (Brennan and others, 2010). This catalog of basins is designed to provide a check list and basic geologic framework for compiling more detailed geologic and reservoir engineering data for this project and other future investigations.

  8. Frontier sedimentary basins of New Zealand region

    SciTech Connect

    Beggs, J.M. )

    1991-03-01

    Petroleum-prospective basins of New Zealand began to form by mid-Cretaceous rifting of crustal elements previously assembled at the Gondwana continental margin. During the latest Cretaceous-early Cenozoic New Zealand separated from Australia and Antarctica by sea-floor spreading. An overall transgression in widely recorded in this post-rift phase, with decreasing clastic sediment supply as land area and relief were reduced. Mid-Cenozoic initiation of the modern plate boundary has resulted in uplift of mountain ranges, subsidence and filling of troughs, progradation of the shelf, and common reactivation or eversion of older structures. Petroleum potential of less explored basins can be compared to the productive Taranki basin. Source rocks are coal-rich deposits of the rift phase, also developed in Great South, Canterbury/Chatham, Western Southland, West Coast, and Northland basins. A different source contributes to oil and gas seeps on the East Coast, a continental margin during Late Cretaceous. The main reservoirs of Taranaki are early Cenozoic coastal and fluvial sands, also present in Great South, Canterbury, and West Coast and possibly other basins. Other Taranaki reservoirs include mid-Cenozoic limestone and Miocene turbidites, which are widespread in most other basins. Pliocene limestones have excellent reservoir potential on the East Coast. Late Cenozoic tectonics, essential to trap development and significant for maturation in Taranaki, have created similar structures in basins near the plate boundary but are less significant in the development of Great South, eastern Canterbury/Chatham, and Northland basins.

  9. Mapping Sedimentary Basins Across Canada Using Receiver Function Analysis

    NASA Astrophysics Data System (ADS)

    Cassidy, J. F.; Kao, H.; Kim, H.; Dehler, S.; Dosso, S.; Halliday, J.

    2008-12-01

    Receiver function studies are being applied within several sedimentary basins across Canada to map basin geometry and sediment thickness. Teleseismic receiver functions are ideal, in many ways, for this type of study. They provide site-specific information, constraints on the shear wave velocity, interface geometry, and they can be used to identify structures from the near-surface to mantle depths. Although the frequency content of teleseismic waveforms limits the resolution, high-frequency receiver functions can resolve layers as thin as 1-2 km. In the Western Canada Sedimentary Basin (near Edmonton, Alberta), receiver functions were used to image the 2.5-km-thick sedimentary package at this site and a low-velocity zone in the upper crust. Currently, a deployment of 10 broadband seismic stations in Atlantic Canada is targeting the Paleozoic and Carboniferous sedimentary basins in the Gulf of St. Lawrence. Significant variations in the arrival time of the continental Moho phase along a north-south transect indicate crustal thickness variations, with the earliest Moho arrivals being in the central part of the basin, indicating a thinner crust here. The direct arrivals in the receiver functions at stations in the southern part of the gulf are broad, indicating notable thicknesses of near-surface sediments. These observations are consistent with what is known about the regional geology and the centrally-located Maritimes Basin. These initial observations, and other geophysical data for the region, will feed into interpretations of crustal structure developed through numerical modelling.In the Nechako Basin of central BC, receiver functions from seven broadband seismograph stations are being used to map sediments in this basin that are overlain by volcanic basalts. These receiver function show clear evidence for shallow dipping low-velocity layers. Constrains on the basin geometry and sediment thickness will be used to improve assessments of oil and gas potential in

  10. Sedimentary sequence evolution in a Foredeep basin: Eastern Venezuela

    SciTech Connect

    Bejarano, C.; Funes, D.; Sarzalho, S.; Audemard, F.; Flores, G.

    1996-08-01

    Well log-seismic sequence stratigraphy analysis in the Eastern Venezuela Foreland Basin leads to study of the evolution of sedimentary sequences onto the Cretaceous-Paleocene passive margin. This basin comprises two different foredeep sub-basins: The Guarico subbasin to the west, older, and the Maturin sub-basin to the east, younger. A foredeep switching between these two sub-basins is observed at 12.5 m.y. Seismic interpretation and well log sections across the study area show sedimentary sequences with transgressive sands and coastal onlaps to the east-southeast for the Guarico sub-basin, as well as truncations below the switching sequence (12.5 m.y.), and the Maturin sub-basin shows apparent coastal onlaps to the west-northwest, as well as a marine onlap (deeper water) in the west, where it starts to establish. Sequence stratigraphy analysis of these sequences with well logs allowed the study of the evolution of stratigraphic section from Paleocene to middle Miocene (68.0-12.0 m.y.). On the basis of well log patterns, the sequences were divided in regressive-transgressive-regressive sedimentary cycles caused by changes in relative sea level. Facies distributions were analyzed and the sequences were divided into simple sequences or sub- sequences of a greater frequencies than third order depositional sequences.

  11. PUMa - modelling the groundwater flow in Baltic Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Kalvane, G.; Marnica, A.; Bethers, U.

    2012-04-01

    In 2009-2012 at University of Latvia and Latvia University of Agriculture project "Establishment of interdisciplinary scientist group and modelling system for groundwater research" is implemented financed by the European Social Fund. The aim of the project is to develop groundwater research in Latvia by establishing interdisciplinary research group and modelling system covering groundwater flow in the Baltic Sedimentary Basin. Researchers from fields like geology, chemistry, mathematical modelling, physics and environmental engineering are involved in the project. The modelling system is used as a platform for addressing scientific problems such as: (1) large-scale groundwater flow in Baltic Sedimentary Basin and impact of human activities on it; (2) the evolution of groundwater flow since the last glaciation and subglacial groundwater recharge; (3) the effects of climate changes on shallow groundwater and interaction of hydrographical network and groundwater; (4) new programming approaches for groundwater modelling. Within the frame of the project most accessible geological information such as description of geological wells, geological maps and results of seismic profiling in Latvia as well as Estonia and Lithuania are collected and integrated into modelling system. For example data form more then 40 thousands wells are directly used to automatically generate the geological structure of the model. Additionally a groundwater sampling campaign is undertaken. Contents of CFC, stabile isotopes of O and H and radiocarbon are the most significant parameters of groundwater that are established in unprecedented scale for Latvia. The most important modelling results will be published in web as a data set. Project number: 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060. Project web-site: www.puma.lu.lv

  12. Jurassic sedimentary basins in the Central Asian orogenic belt

    SciTech Connect

    Bebeshev, I.I.

    1995-05-01

    The principal stages of development of Jurassic sedimentary basins (from their origin to the end of their existence) in the Central Asian orogenic belt are considered. The interrelations of the basins with the surrounding paleorises are investigated. Paleogeographic maps are compiled representing the evolution of paleolandscapes and revealing their interrelations in space and time for each stage. Areas with the highest prospects for coal are found.

  13. Geodynamic evolution of early Mesozoic sedimentary basins in eastern Australia

    NASA Astrophysics Data System (ADS)

    Rosenbaum, G.; Babaahmadi, A.; Esterle, J.

    2014-12-01

    Eastern Australia is covered by a series of continental sedimentary basins deposited during the Triassic and Jurassic, but the geodynamic context of these basins is not fully understood. Using gridded aeromagnetic data, seismic reflection data, geological maps, digital elevation models, and field observations, we conducted a structural synthesis aimed at characterizing major structures and deformation style in the Triassic-Jurassic sedimentary basins of eastern Australia. Our results show evidence for four alternating episodes of rifting and contractional events during the Triassic. Two major episodes of rifting, characterized by syn-sedimentary steep normal faults and bimodal volcanism, resulted in the development of the Early-Middle Triassic Esk-Nymboida Rift System and the early Late Triassic Ipswich Basin. Faults in the Esk-Nymboida Rift System have been controlled by a pre-existing oroclinal structure. Each phase of rifting was followed by a contractional event, which produced folds, reverse faults and unconformities in the basins. Since the latest Late Triassic, thermal subsidence led to the deposition of continental sediments in the Clarence-Moreton Basin, which continued until the Early Cretaceous. We suggest that the geodynamic control on the alternating episodes of rifting and contraction during the Triassic in eastern Australia was ultimately related to plate boundary migration and switches between trench retreat and advance.

  14. Fluvial geomorphic elements in modern sedimentary basins and their potential preservation in the rock record: A review

    NASA Astrophysics Data System (ADS)

    Weissmann, G. S.; Hartley, A. J.; Scuderi, L. A.; Nichols, G. J.; Owen, A.; Wright, S.; Felicia, A. L.; Holland, F.; Anaya, F. M. L.

    2015-12-01

    Since tectonic subsidence in sedimentary basins provides the potential for long-term facies preservation into the sedimentary record, analysis of geomorphic elements in modern continental sedimentary basins is required to understand facies relationships in sedimentary rocks. We use a database of over 700 modern sedimentary basins to characterize the fluvial geomorphology of sedimentary basins. Geomorphic elements were delineated in 10 representative sedimentary basins, focusing primarily on fluvial environments. Elements identified include distributive fluvial systems (DFS), tributive fluvial systems that occur between large DFS or in an axial position in the basin, lacustrine/playa, and eolian environments. The DFS elements include large DFS (> 30 km in length), small DFS (< 30 km in length), coalesced DFS in bajada or piedmont plains, and incised DFS. Our results indicate that over 88% of fluvial deposits in the evaluated sedimentary basins are present as DFS, with tributary systems covering a small portion (1-12%) of the basin. These geomorphic elements are commonly arranged hierarchically, with the largest transverse rivers forming large DFS and smaller transverse streams depositing smaller DFS in the areas between the larger DFS. These smaller streams commonly converge between the large DFS, forming a tributary system. Ultimately, most transverse rivers become tributary to the axial system in the sedimentary basin, with the axial system being confined between transverse DFS entering the basin from opposite sides of the basin, or a transverse DFS and the edge of the sedimentary basin. If axial systems are not confined by transverse DFS, they will form a DFS. Many of the world's largest rivers are located in the axial position of some sedimentary basins. Assuming uniformitarianism, sedimentary basins from the past most likely had a similar configuration of geomorphic elements. Facies distributions in tributary positions and those on DFS appear to display

  15. Mechanisms for generating overpressure in sedimentary basins: A reevaluation

    SciTech Connect

    Osborne, M.J.; Swarbrick, R.E.

    1997-06-01

    Overpressure can be produced by the following processes: (1) increase of compressive stress, (2) changes in the volume of the pore fluid or rock matrix, and (3) fluid movement or buoyancy. Loading during burial can generate considerable overpressure due to disequilibrium compaction, particularly during the rapid subsidence of low-permeability sediments. Horizontal stress changes can rapidly generate and dissipate large amounts of overpressure in tectonically active areas. Overpressure mechanisms involving change in volume must be well sealed to be effective. Fluid volume increases associated with aquathermal expansion and clay dehydration are too small to generate significant overpressure unless perfect sealing occurs. Hydrocarbon generation and cracking to gas could possibly produce overpressure, depending upon the kerogen type, abundance of organic matter, temperature history, and rock permeability; however, these processes may be self-limiting in a sealed system because buildup of pressure could inhibit further organic metamorphism. The potential for generating overpressure by hydrocarbon generation and cracking must be regarded as unproven at present. Fluid movement due to a hydraulic head can generate significant overpressure in shallowly buried, {open_quotes}well-plumbed{close_quotes} basins. Calculations indicate that hydrocarbon buoyancy and osmosis can generate only small amounts of localized overpressure. The upward movement of gas in an incompressible fluid also could generate significant overpressure, but requires further investigation. Stress-related mechanisms are the most likely causes of overpressure in many sedimentary basins.

  16. Hydrogeologic framework of fractured sedimentary rock, Newark Basin, New Jersey

    USGS Publications Warehouse

    Lacombe, Pierre J.; Burton, William C.

    2010-01-01

    The hydrogeologic framework of fractured sedimentary bedrock at the former Naval Air Warfare Center (NAWC), Trenton, New Jersey, a trichloroethylene (TCE)-contaminated site in the Newark Basin, is developed using an understanding of the geologic history of the strata, gamma-ray logs, and rock cores. NAWC is the newest field research site established as part of the U.S. Geological Survey Toxic Substances Hydrology Program, Department of Defense (DoD) Strategic Environmental Research and Development Program, and DoD Environmental Security Technology Certification Program to investigate contaminant remediation in fractured rock. Sedimentary bedrock at the NAWC research site comprises the Skunk Hollow, Byram, and Ewing Creek Members of the Lockatong Formation and Raven Rock Member of the Stockton Formation. Muds of the Lockatong Formation that were deposited in Van Houten cycles during the Triassic have lithified to form the bedrock that is typical of much of the Newark Basin. Four lithotypes formed from the sediments include black, carbon-rich laminated mudstone, dark-gray laminated mudstone, light-gray massive mudstone, and red massive mudstone. Diagenesis, tectonic compression, off-loading, and weathering have altered the rocks to give some strata greater hydraulic conductivity than other strata. Each stratum in the Lockatong Formation is 0.3 to 8 m thick, strikes N65 degrees E, and dips 25 degrees to 70 degrees NW. The black, carbon-rich laminated mudstone tends to fracture easily, has a relatively high hydraulic conductivity and is associated with high natural gamma-ray count rates. The dark-gray laminated mudstone is less fractured and has a lower hydraulic conductivity than the black carbon-rich laminated mudstone. The light-gray and the red massive mudstones are highly indurated and tend to have the least fractures and a low hydraulic conductivity. The differences in gamma-ray count rates for different mudstones allow gamma-ray logs to be used to correlate and

  17. Permo-Carboniferous sedimentary basins related to the distribution of planetary cryptoblemes

    USGS Publications Warehouse

    Windolph, J.F.

    1997-01-01

    Massive/high velocity solar, galactic, and cosmic debris impacting the Earths surface may account for the enormous energy required for the formation of Permo-Carboniferous sedimentary basins and related mountain building orogenies. Analysis of satellite immagry, sea floor sonar, geophysical data, and geotectonic fabrics show a strong correlation throughout geologic time between sedimentary basin origin and planetary cryptoblemes. Cryptoblemes are subtile, multi-ringed, radial centric impact shock signatures covering the entire terrestrial surface and ocean floors, having a geometry and distribution strikingly similar to the surfaces of the lunar planetary bodies in the solar system. Investigations of Permo-Carboniferous basins show an intensely overprinted pattern of cryptoblemes coinciding with partial obliteration and elliptical compression of pre-existing basins and accompanying shock patterns. Large distorted cryptoblemes may incorporate thin skin deformation, localized sediment diagenesis, regional metamorphism, and juxtaposed exotic terrains. These data, related to basin morphogenic symmetry, suggest that large episodic impact events are the primary cause of tectonogenic features, geologic boundary formation and mass extinction episodes on the planet Earth. Plate tectonics may be only a slow moving, low energy secondary effect defined and set in motion by megacosmic accretion events. Permo-Carboniferous sediments of note are preserved or accumulated in relatively small rectangular to arcuate rift valleys and synclinal down warps, such as the Narraganset basin of Massachusetts, USA, and Paganzo basin in Argentina, S.A. These deposits and depocenters may originate from dynamic reinforcement/cancellation impact effects, as can be seen in the Basin Range of Nevada and Utah, USA. Large circular to oval sedimentary basins commonly include internal ring structures indicating post depositional subsidence and rebound adjustments with growth faulting, notable in the

  18. Sedimentary basins and petroleum occurrences, Mongolia

    SciTech Connect

    Nemec, M.C.; Page, M.M.; Penttila, W.C. )

    1991-03-01

    Mongolia is situated on the southern margin of the Siberian craton. Successive tectonostratigraphic terrain accreted to the Laurasian, Siberian craton during the proto-Tethys, paleo-Tethys, and neo-Tethys. These terrains have been described as micro-plates made up of continental, ocean basin and volcanic-arc fragments docking onto the Siberian craton. Extensive, post-accretionary rifting developed during extensional periods of opening and closing of paleo-Tethys and neo-Tethys. Rift and graben deformation was initiated in the Upper Jurassic. Rift-fill included conglomerates, breccias, and volcanics. During the Lower Cretaceous, continental deposits with lacustrine clastics continued as the rift-fill sequence. The Upper Cretaceous continental sediments are related to the wrench-rifting, compressive phase. Geophysical data (gravity, magnetics, and seismic) are used with surface, regional geology, and subsurface well data to illustrate the Mesozoic rift basins' geometry, the thickness of sediments, and the existing type of hydrocarbon traps. The Upper Jurassic-Lower Cretaceous shale-sandstone sequence contains the known source rocks and reservoir rocks in the southeastern and eastern part of Mongolia. These rocks are described and their structural and stratigraphic relationship are illustrated. The known oil occurrences are surface oil seeps, impregnated outcrops, oil shows in core holes and in samples, and cores in exploration wells. The two oil fields that have been discovered in Southeastern Mongolia, Tsagaan-Els and Zuunbayan, are described.

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

    USGS Publications Warehouse

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

    2004-01-01

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

  20. Estimating tectonic history through basin simulation-enhanced seismic inversion: geoinfomatics for sedimentary basins

    NASA Astrophysics Data System (ADS)

    Tandon, Kush; Tuncay, Kagan; Hubbard, Kyle; Comer, John; Ortoleva, Peter

    2004-01-01

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

  1. Strong motion from surface waves in deep sedimentary basins

    USGS Publications Warehouse

    Joyner, W.B.

    2000-01-01

    It is widely recognized that long-period surface waves generated by conversion of body waves at the boundaries of deep sedimentary basins make an important contribution to strong ground motion. The factors controlling the amplitude of such motion, however, are not widely understood. A study of pseudovelocity response spectra of strong-motion records from the Los Angeles Basin shows that late-arriving surface waves with group velocities of about 1 km/sec dominate the ground motion for periods of 3 sec and longer. The rate of amplitude decay for these waves is less than for the body waves and depends significantly on period, with smaller decay for longer periods. The amplitude can be modeled by the equation log y = f(M, RE) + c + bRB where y is the pseudovelocity response, f(M, RE) is an attenuation relation based on a general strong-motion data set, M is moment magnitude, RE is the distance from the source to the edge of the basin, RB is the distance from the edge of the basin to the recording site, and b and c are parameters fit to the data. The equation gives values larger by as much as a factor of 3 than given by the attenuation relationships based on general strong-motion data sets for the same source-site distance. It is clear that surface waves need to be taken into account in the design of long-period structures in deep sedimentary basins. The ground-motion levels specified by the earthquake provisions of current building codes, in California at least, accommodate the long-period ground motions from basin-edge-generated surface waves for periods of 5 sec and less and earthquakes with moment magnitudes of 7.5 or less located more than 20 km outside the basin. There may be problems at longer periods and for earthquakes located closer to the basin edge. The results of this study suggest that anelastic attenuation may need to be included in attempts to model long-period motion in deep sedimentary basins. To obtain better data on surface waves in the future

  2. Self-Organized Megastructures in Sedimentary Basins

    SciTech Connect

    Peter J. Ortoleva

    2004-06-30

    The overall theme of the project is to develop a quantitative understanding of basin reaction/transport/mechanical (RTM) processes on a broad range of scales. Our approach starts with the development of novel formulations of the basic RTM process rate laws (e.g. rock deformation, texture dynamics, and fracturing). We then set forth algorithms for solving the resulting partial differential equations numerically. As many of the parameters in the subsurface are not well known, we embed the entire approach in a probabilistic framework through information theory. The result is a set of novel software and conceptual papers that have been the first quantitative theory of a number of fundamental phenomena that take into account the full RTM dynamics of these systems.

  3. The sedimentary and crustal velocity structure of Makarov Basin and adjacent Alpha Ridge

    NASA Astrophysics Data System (ADS)

    Evangelatos, John; Funck, Thomas; Mosher, David C.

    2017-01-01

    This study examines the velocity structure of Makarov Basin and the adjacent Alpha Ridge to determine the tectonic origins of these features and link them to the larger Amerasia Basin. Seismic data from sonobuoys distributed along a 650 km-long line extending from Alpha Ridge and across Makarov Basin to the Lomonosov Ridge were analyzed for this purpose. Forward modelling of traveltimes, supported by coincident multi-channel seismic reflection and shipborne gravity data, were used to determine the P-wave velocity structure along the line. The sedimentary cover averages 0.5 km-thick on Alpha Ridge and 1.9 km-thick in Makarov Basin, but reaches up to 5 km-thick at the base of Lomonosov Ridge. Velocities in the sedimentary section range from 1.6 to 4.3 km s- 1. As suggested by relatively high velocities, interbedded volcaniclastic or volcanic rock may occur in the deep sedimentary section. The shallow basement of Alpha Ridge (3.3 to 3.6 km s- 1) is characterized by semi-continuous high amplitude reflections and is interpreted as volcanic rock possibly intercalated with sedimentary rock. Velocities do not vary significantly in the upper and mid-crustal layers between Alpha Ridge and Makarov Basin. Total crustal thickness decreases from 27 km beneath Alpha Ridge to 5 km-thick in Makarov Basin then thickens to > 20 km over a short distance as part of Lomonosov Ridge. The crustal structure of Alpha Ridge is consistent with previous studies suggesting that the Alpha-Mendeleev ridge complex is part of a large igneous province (LIP) with thick igneous crust. The lack of change in crustal velocities between Alpha Ridge and Makarov Basin suggests that the basin, at least partly, either formed during or was influenced by LIP-related magmatism. The rapid transition of crustal thicknesses from Makarov Basin to Lomonosov Ridge supports the interpretation that this section of the ridge is a transform margin.

  4. Exploration matrix evaluation of sedimentary basins of Colombia

    SciTech Connect

    Kanes, W.H.; Bueno, R.

    1989-03-01

    The sedimentary basins of Colombia are evaluated for the following five exploration criteria: (1) source rock potential, including total organic carbon, Rock-Eval analysis, and kerogen types; (2) seals, with specific units and lithologies designated in each basin; (3) reservoirs characteristics, with stress laid on porosity and permeability fairways developed in the various types of clastic depositional systems; (4) traps, whether structural or stratigraphic, and the most probable routes of hydrocarbon migration; and (5) timing, which also examines the interrelationship between maturation and expulsion of hydrocarbon and the formation of the structural or stratigraphic trap and seal. The exploration matrix is based on delineating the play concepts (up to five) for each sedimentary basin. These play concepts are based on a linear scale based on the probability of future or potential discoveries. All data for the analyses were provided by Ecopetrol and were subjectively weighed only where the number of wells in the basin was low in contrast to the basin area (<1:100 km/sup 2/) and there was no history of production.

  5. Sedimentary basin framework of Exmouth Plateau, northwest Australia

    SciTech Connect

    Boyd, R.; Exon, N.; Williamson, P.

    1987-05-01

    The Exmouth Plateau is a marginal plateau lying off northwest Australia. Water depths range between 800 m and 4000 m, and the area shallower than 2000 m covers approximately 150,000 km/sup 2/. The plateau consists of rifted and deeply subsided continental crust, with a Phanerozoic sedimentary sequence around 10 km thick, deposited in the Canning and Carnarvon basins. The plateau is separated from the Northwest Shelf by the Kangaroo syncline and is bounded to the north, west, and south by oceanic crust of Cretaceous and Jurassic age. The present structural configuration of Exmouth Plateau was initiated by rifting in the Triassic to Middle Jurassic, followed by northwest-oriented sea floor spreading. The western margin has a normal rifted structure, while the southern margin structure was dominated by transform motion. The complex rifted and sheared northern margin contains at least one crustal block of post-breakup igneous origin. Below a rift onset unconformity of Neocomian age lies a thick Triassic paralic sequence to the south, while farther north the unconformity is of Callovian age and overlies a Jurassic sequence of Tethyan carbonates, coal measures, and volcanics. The post-breakup sequence consists of Late Jurassic-Cenomanian deltaic and shelf clastics, overlain by thin Late Cretaceous-Tertiary shallow marine to pelagic carbonates. Exmouth Plateau therefore represents classic rift to mature ocean stage development of a sediment-starved passive margin. The large fault blocks in the rifted Triassic-Jurassic sequences and large areal closures in the Cretaceous deltas encouraged petroleum exploration over the last two decades. The rifted section was shown to be gas prone, while the overlying section proved to be largely immature.

  6. Multilayered aquifer modeling in the coastal sedimentary basin of Togo

    NASA Astrophysics Data System (ADS)

    Gnazou, M. D. T.; Sabi, B. E.; Lavalade, J. L.; Schwartz, J.; Akakpo, W.; Tozo, A.

    2017-01-01

    This work is a follow up to the hydrogeological synthesis done in 2012 on the coastal sedimentary basin of Togo. That synthesis notably emphasized the lack of piezometric monitoring in the last thirty years. This has kept us from learning about the dynamics and evolution of the resource in the context of rapidly increasing demand. We are therefore presenting a model for understanding flows, and its main objectives are to provide an initial management tool that should evolve with time as new data (piezometric monitoring, pumping tests, etc.) become available, and to determine what new information can be obtained that will help policy makers to manage the resource better. The results of steady state flow calibration have shown that the aquifer of the Continental Terminal overexploited in the West, can still be exploited in the East of the basin, the Maastrichtian on the whole basin. On the other hand, exploitation of Paleocene aquifers should be done with care.

  7. Sedimentary fill and stratigraphic traps of Porcupine basin, offshore Ireland

    SciTech Connect

    Macurda, D.B. Jr.

    1986-05-01

    The Porcupine basin, off the southwest coast of Ireland, is a triangular north-south re-entrant into the present-day continental shelf. This aulacogen was formed in the Jurassic during the opening of the North Atlantic. A seismic stratigraphic investigation of the southern part of the basin has shown the complex evolution of the sedimentary fill from shallow to deep water facies, resulting in several stratigraphic traps. The central axis of the basin is dominated by a volcanic ridge. Part of the early sedimentary fill was intermittently covered by volcanic flows. The final stage of thin initial siliciclastic infill was the development of an extensive alluvial fan or fan-delta complex along the eastern basin margin. Aerially extensive carbonate sedimentation occurred during the Cretaceous, including a north-south reef tract more than 20 km wide in the eastern part of the basin. Increased subsidence resulted in the deposition of deep water siliciclastics in the Tertiary. The most prominent of these is a series of lower Tertiary submarine fans that were sourced from the western, northern, and eastern margins of the aulacogen. The early portions of the fans correlate well basin-wide; their later history is much more complex, with younger lobes up to 25 km wide developing south of their precursors. Subsequent onlap fill deposits provide an excellent seal. Sedimentation in the late Tertiary has included both high-energy and low-energy deep water deposits. The complex fill of the aulacogen has set up several stratigraphic plays, including carbonate reefs, alluvial fans of fan deltas, and submarine fans. Seismic amplitude anomalies in the latter suggest the heat flow has been sufficient to generate hydrocarbons to fill some of the traps.

  8. Buried Proterozoic foredeep under the Western Canada Sedimentary Basin?

    NASA Astrophysics Data System (ADS)

    Boerner, D. E.; Kurtz, R. D.; Craven, J. A.; Rondenay, S.; Qian, W.

    1995-04-01

    Electromagnetic studies of the Precambrian basement beneath the Western Canada Sedimentary Basin in Alberta indicate a narrow linear conductivity anomaly spatially correlated with a strong positive magnetic feature, the Red Deer high. The conductor is located below sedimentary cover near the top of the crystalline basement and has limited depth extent. We propose that this anomalous feature represents graphitic metasedimentary rocks in the euxinic-flysch facies of a Proterozoic foredeep sequence. The strong magnetic anomaly results from an associated iron formation deposited on the outer ramp of the foredeep. This model explains the geophysical anomalies, has analogues on the exposed shield, and is consistent with the timing, deformation history, and known geology of the Precambrian basement.

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  10. Walled Sedimentary Basins of China: Perpetrators or Victims of Plateau Growth?

    NASA Astrophysics Data System (ADS)

    Carroll, A. R.; Graham, S. A.; Smith, M. E.

    2004-12-01

    Western China and adjacent areas of central Asia are characterized by low relief, internally drained sedimentary basins that are divided by actively uplifting mountain ranges. The margins of these basins often show evidence for extensive contractional deformation, yet their interiors are surprisingly stable. Basins such as the Tarim and Junggar also exhibit long and apparently continuous histories of closed drainage in the same approximate location (over 250 my in the case of Junggar). In contrast to traditional foreland basins, these basins are not uniquely associated with a specific thrust belt, nor do they show evidence for underlying decollements. We therefore propose the new term "walled basin", in recognition of the essential role of peripheral orogenic walls in creating and maintaining closed drainage and impounding sediments. Walled basins in Asia currently are restricted to areas that receive less than 40 cm/yr precipitation, suggesting that aridity plays a role in preventing fluvial breach of the basin walls (cf., Sobel et al., 2003). Entrapment of sediment within the closed Qaidam basin in the northeast Tibetan plateau has been implicated as a potential mechanism of plateau growth, based on the observations that the basin retains mass within the orogen and creates level topography. However, we propose that the Qaidam instead represents a walled basin that has been elevated due to underplating of the plateau, and is fated to eventual destruction as deformation continues. Several lines of reasoning support this conclusion. First, DEM analysis shows that modern drainage divides for the Qaidam and other walled basins never rise more than 1-2 km above the basin floors, limiting the amount of possible topgraphic infill. Second, the Tarim and Junggar basins presently remain well below 2000 m and probably have never been higher, despite receiving large influxes of detritus from adjacent ranges. Third, the Qaidam basin, like the Tarim and Junggar basins, has an

  11. The South China - Indochina collision: a perspective from sedimentary basins analysis

    NASA Astrophysics Data System (ADS)

    Rossignol, Camille; Bourquin, Sylvie; Hallot, Erwan; Poujol, Marc; Roger, Françoise; Dabard, Marie-Pierre; Martini, Rossana; Villeneuve, Michel; Cornée, Jean-Jacques; Peyrotty, Giovan

    2017-04-01

    material, emplaced under continental setting and representing the product of the erosion of the Indosinian mountain belt. To the North, the Song Da Basin is characterized by strongly diachronous deposits over a basal unconformity developed at the expense of volcanic and volcaniclastic deposits related to the Emeishan Large Igneous Province. The sedimentary succession indicates a foreland setting during the Early to the Middle Triassic, which contrasts with the commonly assumed rift setting for these sediments. Thus, the Song Da Basin documents the formation of the Indosinian thrust belt, located immediately to the South of the basin.

  12. Research into surface wave phenomena in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Wojcik, G. L.; Isenberg, J.; Ma, F.; Richardson, E.

    1981-12-01

    This study is a continuation of an engineering seismology research effort prompted by the sensitivity of guidance sets in Minuteman Wing V to distant earthquakes. An earlier report considers the probable cause of anomalous patterns of seismic alarms triggered by two North American earthquakes. This report extends the previous study by examining the propagation of surface waves from the 1975 Pocatello Valley, Idaho earthquake sequence across Wyoming to Wing V. In addition, the more general question of surface wave phenomena in sedimentary basins is addressed, particularly the effect of laterally inhomogeneous (dipping) basin-bedrock interfaces. Findings indicate that fundamental and first overtone surface waves are significantly modified by the travel path. In contrast, higher modes are relatively unchanged by the travel path, and affect Wing V in much the same way as body waves considered in the previous study.

  13. Sedimentary basins reconnaissance using the magnetic Tilt-Depth method

    USGS Publications Warehouse

    Salem, A.; Williams, S.; Samson, E.; Fairhead, D.; Ravat, D.; Blakely, R.J.

    2010-01-01

    We compute the depth to the top of magnetic basement using the Tilt-Depth method from the best available magnetic anomaly grids covering the continental USA and Australia. For the USA, the Tilt-Depth estimates were compared with sediment thicknesses based on drilling data and show a correlation of 0.86 between the datasets. If random data were used then the correlation value goes to virtually zero. There is little to no lateral offset of the depth of basinal features although there is a tendency for the Tilt-Depth results to be slightly shallower than the drill depths. We also applied the Tilt-Depth method to a local-scale, relatively high-resolution aeromagnetic survey over the Olympic Peninsula of Washington State. The Tilt-Depth method successfully identified a variety of important tectonic elements known from geological mapping. Of particular interest, the Tilt-Depth method illuminated deep (3km) contacts within the non-magnetic sedimentary core of the Olympic Mountains, where magnetic anomalies are subdued and low in amplitude. For Australia, the Tilt-Depth estimates also give a good correlation with known areas of shallow basement and sedimentary basins. Our estimates of basement depth are not restricted to regional analysis but work equally well at the micro scale (basin scale) with depth estimates agreeing well with drill hole and seismic data. We focus on the eastern Officer Basin as an example of basin scale studies and find a good level of agreement between previously-derived basin models. However, our study potentially reveals depocentres not previously mapped due to the sparse distribution of well data. This example thus shows the potential additional advantage of the method in geological interpretation. The success of this study suggests that the Tilt-Depth method is useful in estimating the depth to crystalline basement when appropriate quality aeromagnetic anomaly data are used (i.e. line spacing on the order of or less than the expected depth to

  14. Seismic interaction between a building network and a sedimentary basin

    NASA Astrophysics Data System (ADS)

    Kham, M.; Semblat, J. F.; Bard, P. Y.; Gueguen, P.

    2003-04-01

    The classical procedure to assess the seismic risk for a superficial structure consists in distinguishing firstly the characterization of the seismic hazard and secondly the analysis of the structure vulnerability. But, as far as the entire urban area is concerned by the seismic risk, a network of superficial structures may influence the free-field motion. In this way, convergent observations were made during the 1985 Mexico earthquake where the large increase in duration may not be completely explained only by site effects. This phenomenon involving the interaction between a city and the sedimentary basin is called Site-City Interaction (SCI) and was firstly underlined by Gueguen [1] in Volvi european test site. Under seismic excitation, the energy radiated by the city back into the soil seems to be mainly controlled by the eigenfrequency ratio fB/fs between the buildings and the soil as well as the urban density. Nevertheless, the key parameters supporting or controlling the SCI effect mainly remain unknown. This point is all the more obvious since present studies on the issue suffer a lack of experimental data characterizing the "urban free field". In the present work, we aim to quantify the specific role of some parameters characterizing the city on seismic hazard modification, such as the urban density, the resonance frequency of the buildings in the city, its homogeneity level (one or several types of different buildings) or the periodicity (or not) of the buildings distribution. To this purpose, a boundary element model is considered which comprises alluvial layers over a rigid elastic basement and superficial buildings. Impedance contrast is taken to 5 in order to support the trapping of the incident energy inside the superficial layers. The whole system is then submitted to a Ricker signal which frequency is successively adjusted to the city and the soil fundamental frequencies. The case of Nice city (France) over a two dimensional basin is then considered

  15. Tectonosedimentary history of the sedimentary basins in northern west Siberia

    SciTech Connect

    Kunin, N.Ya.; Segalovich, I.E. )

    1993-09-01

    Sedimentary basins of northern west Siberia belong to the Arctic tectonosedimentary province. This basin evolved dissimilarly compared to those in the Urengoy and more southern areas, which resulted in substantial differences in the geologic characteristics. Seismic surveys indicate that the basement surface in northern west Siberia occurs at great depths, in places exceeding 15 km. The depressions of the basement surfaces are filled with the thick Paleozoic and Mesozoic sequences. The paper discussed the results of seismostratigraphic analysis of more than 13,000 km of regional common-depth-point profiles. These profiles identified systems of east-west-trending and isometric structures in the region. Some of the structures are buried; others are mapped in the upper horizons of the sedimentary cover and decrease in magnitude with depth. Cretaceous marine sediments that were deposited under deep-water conditions and did not compensate for the tectonic subsidence are widely present in the region. Noncompensated sedimentation was the longest from the Late Jurassic to the Hauterivian-Barremian on the Gydan peninsula and in adjacent areas. The Jurassic section is dominate by ingressive marine sediments. Sediments that did not compensate for tectonic subsidence widely occurred in the Early Jurassic and resulted in deposition of petroleum source rocks. Triassic and Jurassic strata occur conformable in most of northern west Siberia. Significant deformation of the Triassic sediments are identified in the periphery of the Triassic marine basin. This indicates that surrounding structures were thrust against northern west Siberia at the Triassic and Jurassic time boundary. Isometric structures of high magnitude were formed during the Paleozoic structure stage and these structures continued to grow through the Triassic and Jurassic. These and other results of seismostratigraphic analysis suggest the high oil potential of the region.

  16. Plio-Pleistocene drainage development in an inverted sedimentary basin: Vera basin, Betic Cordillera, SE Spain

    NASA Astrophysics Data System (ADS)

    Stokes, Martin

    2008-08-01

    The Vera basin is one of a series of interconnected Neogene-Quaternary sedimentary basins located within the Internal Zone of the Betic Cordillera (southeast Spain). Since the Pliocene the Vera basin has been subjected to low uplift rates (11-21 m Ma - 1 ) and inverted via compressive tectonics that are related to the ongoing oblique collision between the African and Iberian plates. Within this paper the sedimentary and geomorphic response to basin inversion is explored. Sedimentary processes and environments are established for key stratigraphic units of the Pliocene/Plio-Pleistocene basin fill and Pleistocene dissectional landscape. These data are subsequently utilised to reconstruct an evolving basin palaeogeography. Fault and uplift data are employed to discuss the role of tectonically driven basin inversion for controlling the resultant palaeogeographic changes and associated patterns of drainage development. During the Early-Mid Pliocene the Vera basin was characterised by shallow marine shelf conditions (Cuevas Formation). A major palaeogeographic reorganisation occurred during the Mid-Late Pliocene. Strike-slip movement along the eastern basin margin, coupled with uplift and basin emergence created a protected, partially enclosed marine embayment that was conducive for Gilbert-type fan-delta sedimentation from fluvial inputs along the northern and eastern basin margins (Espíritu Santo Formation). The Vera basin then became fully continental and internally drained through the development of a consequent drainage network that formed following the withdrawal of marine conditions during the Late Pliocene to Early Pleistocene. Alluvial fans developed along the northern and western basin margins, grading to a bajada and terminating in a playa lake in central basin areas (Salmerón Formation). During the Early-Mid Pleistocene a switch from basin infilling to dissection took place, recorded by alluvial fan incision, a switch to braided river sedimentation and

  17. Inverse geothermal modelling applied to Danish sedimentary basins

    NASA Astrophysics Data System (ADS)

    Poulsen, Søren E.; Balling, Niels; Bording, Thue S.; Mathiesen, Anders; Nielsen, Søren B.

    2017-10-01

    This paper presents a numerical procedure for predicting subsurface temperatures and heat-flow distribution in 3-D using inverse calibration methodology. The procedure is based on a modified version of the groundwater code MODFLOW by taking advantage of the mathematical similarity between confined groundwater flow (Darcy's law) and heat conduction (Fourier's law). Thermal conductivity, heat production and exponential porosity-depth relations are specified separately for the individual geological units of the model domain. The steady-state temperature model includes a model-based transient correction for the long-term palaeoclimatic thermal disturbance of the subsurface temperature regime. Variable model parameters are estimated by inversion of measured borehole temperatures with uncertainties reflecting their quality. The procedure facilitates uncertainty estimation for temperature predictions. The modelling procedure is applied to Danish onshore areas containing deep sedimentary basins. A 3-D voxel-based model, with 14 lithological units from surface to 5000 m depth, was built from digital geological maps derived from combined analyses of reflection seismic lines and borehole information. Matrix thermal conductivity of model lithologies was estimated by inversion of all available deep borehole temperature data and applied together with prescribed background heat flow to derive the 3-D subsurface temperature distribution. Modelled temperatures are found to agree very well with observations. The numerical model was utilized for predicting and contouring temperatures at 2000 and 3000 m depths and for two main geothermal reservoir units, the Gassum (Lower Jurassic-Upper Triassic) and Bunter/Skagerrak (Triassic) reservoirs, both currently utilized for geothermal energy production. Temperature gradients to depths of 2000-3000 m are generally around 25-30 °C km-1, locally up to about 35 °C km-1. Large regions have geothermal reservoirs with characteristic temperatures

  18. The thermal stability of organic acids in sedimentary basins

    SciTech Connect

    Crossey, L.J. )

    1991-03-01

    Water-soluble organic compounds in subsurface brines directly affect the evolution of porosity and permeability during sedimentary diagenesis. Recent examination of the aqueous thermal degradation of oxalic acid (a naturally occurring dicarboxylic acid) and its anions has implications for the thermal stability of dicarboxylic acids under sedimentary basin conditions. Because the thermal stability of these compounds is pH-dependent, consideration of the dissociation behavior of carboxylic acids as a function of temperature is essential for estimating the longevity of difunctional carboxylic acids. Results of burial history models suggest that dicarboxylic acid species may be long-lived in formation waters. Comparison with other experimental studies of carboxylic acids and their anion indicates that acetate stability is greater than formate stability, which is greater than oxalate stability, which is greater than gallate and malonate stability. In addition to the implications of natural systems, the aqueous degradation behavior is critical in evaluating other types of experimental results; notably mineral dissolution studies performed at elevated temperatures in the presence of organic materials and hydrous pyrolysis experiments involving kerogens.

  19. M7+ Virtual Earthquakes near Kanto Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Denolle, M.; Boué, P.; Hirata, N.; Nakagawa, S.; Miyake, H.; Beroza, G. C.

    2015-12-01

    The Tokyo Metropolitan area is subject to high earthquake activity due to its location near the complex junction of three plates. The seismic hazard Tokyo faces is amplified because it lies in the Kanto basin. The Itoigawa-Shizuoka Tectonic Line (ISTL) is one of the crustal fault zones that comprise these plate boundaries. The ISTL accommodates plate motion between the North American Plate and the Eurasian Plate, hosts oblique-strike slip earthquakes with magnitudes greater than 7, and is only ~ 150-200km away from Tokyo. It is thought to be at a mature stage in its seismic cycle, and predicting strong ground motion from earthquakes on it is important for seismic hazard assessment. We take advantage of the dense seismic network MeSO-net (MEtropolitan Seismic Observation network) and of the locations of the Hi-net (High Sensitivity Seismograph network) stations near the ISTL fault to build virtual earthquakes from the ambient seismic field. First, we construct the Earth's impulse responses from deconvolution of the ambient seismic field recorded between Hi-net stations (as sources) and MeSO-net stations (as receivers) with a method that preserves the relative amplitudes of the response. Fundamental and higher modes are often excited in sedimentary basins and we isolate them in the waveforms through phase velocity analysis in the frequency-wavenumber domain. The virtual earthquake approach turns each station-source near the fault into a double-couple point source by correcting the 9-component impulse response for source depth and mechanism. We use recordings of the M6.7 Northern Nagano earthquake that occurred on November 22, 2014 at the northern end of the fault segment to calibrate absolute amplitudes. We estimate the long period (1-10 seconds) ground motions for a suite of of M7+ scenario ruptures on the ISTL and explore the role of waveguides, basin resonance, and basin edges in strong ground motion.

  20. Modeling Variable-Density Fluid Flow and Solute Transport in Glaciated Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    McIntosh, J. C.; Garven, G.; Hanor, J. S.

    2005-12-01

    Sedimentary basins typically contain saline formation waters (35 to >250 g/L TDS) with relatively long residence times (Kyrs to Myrs). Advance and retreat of km-thick ice sheets, as recently as the Late Pleistocene (<18 ka BP), exposed regional aquifers along the margins of northern latitude basins. Overpressuring of aquifers beneath the wet-based glaciers forced meltwaters to great depths in subsurface flow systems, significantly diluting remnant saline fluids and reorganizing salinity structures. Permafrost zones outboard of the ice sheet margins further enhanced deep circulation of glacial recharge. In basins containing shallow evaporites, meltwaters dissolved large quantities of halite, generating relatively recent (<1 Ma) NaCl brines. Furthermore, glacial recharge promoted generation of economic deposits of microbial methane in shallow organic-rich sediments. To better constrain the impact of glaciation on variable-density fluid flow and solute transport in sedimentary basins, we constructed a transient 2D finite element model of the northern half of the glaciated Michigan Basin. The circular basin is relatively tectonically undeformed and contains ~4 km of Paleozoic strata, primarily composed of carbonates, clastics and bedded evaporites. Thick glacial drift deposits (up to ~300 m) form most of the topographic relief in this low-lying intracratonic region. The salinity of basin fluids sharply increases from <0.5 g/L TDS near the surface to >350 g/L at ~800 m depth. Modern groundwater flow is primarily restricted to shallow glacial drift aquifers, with discharge to the Great Lakes. During Pleistocene glaciation, however groundwater flow patterns were reversed, and meteoric waters were routed into Paleozoic carbonate and siliclastic basinal aquifer systems, depressing the freshwater-saline water mixing zones and dissolving halite. Dilute waters (<100 g/L TDS) migrated ~200 km laterally into the Devonian carbonate aquifers. Carbon-14 ages and δ18O values of

  1. Ground Motion Prediction Atop Geometrically Complex Sedimentary Basins - The Dead Sea Basin

    NASA Astrophysics Data System (ADS)

    Shani-Kadmiel, S.; Tsesarsky, M.; Louie, J. N.; Gvirtzman, Z.

    2014-12-01

    The Dead Sea Transform (DST) is the source for some of the largest earthquakes in the eastern Mediterranean. Several deep and structurally complex sedimentary basins are associated with the DST. These basins are up to 10 km deep and typically bounded by active fault zones. The low seismicity of the DST combined with the limited instrumental coverage of the seismic network in the area result in a critical knowledge gap. Therefore, it is necessary to complement the limited instrumental data with synthetic data based on computational modeling, in order to study the effects of earthquake ground motion in these sedimentary basins. We performed a 2D ground-motion analysis in the Dead Sea Basin (DSB) using a finite-difference code. Results indicate a complex pattern of ground motion amplification affected by the geometric features in the basin. To distinguish between the individual contributions of each geometrical feature in the basin, we developed a semiquantitative decomposition approach. This approach enabled us to interpret the DSB results as follows: (1) Ground-motion amplification as a result of resonance occurs basin-wide due to a high impedance contrast at the base of the uppermost layer; (2) Steep faults generate a strong edge-effect that further ampli- fies ground motions; (3) Sub-basins cause geometrical focusing that may significantly amplify ground motions; and (4) Salt diapirs diverge seismic energy and cause a de- crease in ground-motion amplitude. We address the significance of ground motion amplification due to geometrical focusing via an analytical and numerical study. We show that effective geometrical focusing occurs for a narrow set of eccentricities and velocity ratios, where seismic energy is converged to a region of ±0.5 km from surface. This mechanism leads to significant ground motion amplification at the center of the basin, up to a factor of 3; frequencies of the modeled spectrum are amplified up to the corner frequency of the source.

  2. Combining electromagnetic measurements in the Mygdonian sedimentary basin, Greece

    NASA Astrophysics Data System (ADS)

    Autio, U.; Smirnov, M. Yu.; Savvaidis, A.; Soupios, P.; Bastani, M.

    2016-12-01

    We present a novel approach where time-domain electromagnetic (TEM) data are transformed and subsequently used in two-dimensional (2-D) magnetotelluric inversion of the determinant of the impedance tensor. The main idea is to integrate TEM with magnetotelluric (MT) data to produce subsurface electrical resistivity models. Specifically, we show that 2-D MT data inversion of the determinant of the impedance tensor supported by inclusion of TEM-MT-transformed data has superior resolution at the near surface and at the same time static shift afflicting the MT data can be addressed. Thus, the approach allows for practical express integration of TEM data with MT measurements as opposed to a full combined 3-D inversion, which requires significant resources. The approach is successfully applied in the Mygdonian sedimentary basin located in Northern Greece. In addition to TEM and MT data, also controlled source - and radiomagnetotelluric data are available from the Mygdonian basin, which have been subjected to 2-D analysis previously. We have extended the analysis to a full 3-D inversion using ModEM code. All obtained models are analysed and are in a good agreement.

  3. Deep injection of waste water in the Western Canada sedimentary basin.

    PubMed

    Ferguson, Grant

    2015-01-01

    Injection of wastes into the deep subsurface has become a contentious issue, particularly in emerging regions of oil and gas production. Experience in other regions suggests that injection is an effective waste management practice and that widespread environmental damage is unlikely. Over the past several decades, 23 km(3) of water has been injected into the Western Canada Sedimentary Basin (WCSB). The oil and gas industry has injected most of this water but large amounts of injection are associated with mining activities. The amount of water injected into this basin during the past century is 2 to 3 orders magnitude greater than natural recharge to deep formations in the WCSB. Despite this large-scale disturbance to the hydrogeological system, there have been few documented cases of environmental problems related to injection wells. Deep injection of waste appears to be a low risk activity based on this experience but monitoring efforts are insufficient to make definitive statements. Serious uncharacterized legacy issues could be present. Initiating more comprehensive monitoring and research programs on the effects of injection in the WCSB could provide insight into the risks associated with injection in less developed sedimentary basins. © 2014, National Ground Water Association.

  4. On Restoring Sedimentary Basins for Post-Depositional Deformation - Paleozoic Basins of the Central Andes

    NASA Astrophysics Data System (ADS)

    Bahlburg, H.

    2015-12-01

    The reconstruction and interpretation of sedimentary basins incorporated into folded and thrusted mountain belts is strongly limited by the style and intensity of shortening. This problem is exacerbated if deformation is polyphasic as is the case for the Paleozoic basins in the central Andes. Some of these have been deformed by folding and thrusting during at least 3 events in the Late Ordovician, the Late Paleozoic and Cenozoic. A realistic reconstruction of the original basin dimensions and geometries from outcrops and maps appears to be almost impossible. We present results of a stepwise reconstruction of the Paleozoic basins of the central Andes by restoring basin areas and fills accounting for crustal shortening. The structurally most prominent feature of the central Andes is the Bolivian Orocline which accomodated shortening in the last 45 Ma on the order of between 300 and 500 km. In a first step basins were restored by accounting for Cenozoic rotation and shortening by deconvolving the basins using an enhanced version of the oroclinal bending model of Ariagada et al. (2008). Results were then restored stepwise for older deformation. Constraints on these subsequent steps are significantly poorer as values of shortening can be derived only from folds and thusts apparent in outcrops. The amount of shortening accomodated on unexposed and therefore unknown thrusts can not be quantified and is a significant source of error very likely leading to an underestimation of the amount of shortening. Accepting these limitations, basin restoration results in an increase in basin area by ≥100%. The volumes of stratigraphically controlled basin fills can now be redistributed over the wider, restored area, translating into smaller rates of accumulation and hence required subsidence. The restored rates conform to those of equivalent modern basin settings and permit a more realistic and actualistic analysis of subsidence drivers and the respective tectonic framework.

  5. Coseismic growth of sedimentary basins along the Yammouneh strike-slip fault (Lebanon)

    NASA Astrophysics Data System (ADS)

    Nemer, Tony; Gomez, Francisco; Al Haddad, Sharbel; Tabet, Charles

    2008-12-01

    The left-lateral Yammouneh fault (YF) is the main active branch of the Dead Sea Transform Fault (DSTF) within the Lebanese restraining bend. Despite the overall transpressional setting, a series of sedimentary basins have developed along the trace of the YF. Consequently, palaeoseismic studies within these basins provide an opportunity to study the processes of coseismic growth of the basins, as well as elucidate earthquake behaviour of the fault, in general. Geodetic measurements of contemporary fault slip within the Lebanese restraining bend indicate that the YF accommodates most of the expected left-lateral strike-slip motion, despite the apparent lack of present-day seismicity. We studied the YF, using combined investigations of remote imagery, geomorphology and palaeoseismology. The active fault trace along a 51 km strip was delineated as relatively young surface ruptures and fault scarps that affect Holocene deposits with intermittent offset geomorphic markers. Seven closed basins that occur along-strike of the YF, were found to be related to faulting, with at least three of them displaying evident pull-apart settings. We concentrated our work on the rhombohedral Yammouneh basin, an actively evolving example of pull-apart basins, which is presently obliquely cut by the active fault, with an apparently young age of 1.4 +/- 0.3 Myr. 3-D correlation and analysis of palaeoseismic investigations exposed a composite shear zone with a total subsidence that exceeds 1.6 m over the past 4000-4400 yr. Stratigraphic and geochronological constraints suggest the occurrences of at least five large faulting events during that period. By correlating the stratigraphy and ages of this trench with a previously published study located nearby, a combined palaeoseismic history for the past five events is constructed. This suggests a mean recurrence period of 1020-1175 yr for large earthquakes along this section of the YF. Our results suggest a subsidence rate due to faulting of

  6. The Lusi eruption and implications for understanding fossil piercement structures in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Svensen, Henrik; Mazzini, Adriano; Planke, Sverre; Hadi, Soffian

    2016-04-01

    The Lusi eruption started in northeast Java, Indonesia, on May 29th 2006, and it has been erupting rocks, mud, water, and gas ever since. We have been doing field work and research on Lusi ever since the eruption commenced. This work was initially motivated from studying the initiation of a mud volcano. However, the longevity of the eruption has made it possible to describe and monitor the lifespan of this unique piercement structure. . One of the first-order questions regarding the eruption is how it should be classified and if there are any other modern or fossil analogues that can place Lusi in a relevant geological context. During the initial stages of eruption, Lusi was classified as a mud volcano, but following geochemical studies the eruption did not show the typical CH4-dominated gas composition of other mud volcanoes and the temperature was also too high. Moreover, mud volcano eruptions normally last a few days, but Lusi never stopped during the past decade. In particular, the crater fluid geochemistry suggests a connection to the neighboring volcanic complex. Lusi represent a sedimentary hosted hydrothermal system. This opens up new possibilities for understanding fossil hydrothermal systems in sedimentary basins, such as hydrothermal vent complexes and breccia-pipes found in sedimentary basins affected by the formation of Large igneous provinces. We will present examples from the Karoo Basin (South Africa) and the Vøring Basin (offshore Norway) and discuss how Lusi can be used to refine existing formation models. Finally, by comparing Lusi to fossil hydrothermal systems we may get insight into the processes operating at depth where the Lusi system interacts with the igneous rocks of the neighbouring volcanic arc.

  7. Inverse modeling of geochemical and mechanical compaction in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Colombo, Ivo; Porta, Giovanni Michele; Guadagnini, Alberto

    2015-04-01

    We study key phenomena driving the feedback between sediment compaction processes and fluid flow in stratified sedimentary basins formed through lithification of sand and clay sediments after deposition. Processes we consider are mechanic compaction of the host rock and the geochemical compaction due to quartz cementation in sandstones. Key objectives of our study include (i) the quantification of the influence of the uncertainty of the model input parameters on the model output and (ii) the application of an inverse modeling technique to field scale data. Proper accounting of the feedback between sediment compaction processes and fluid flow in the subsurface is key to quantify a wide set of environmentally and industrially relevant phenomena. These include, e.g., compaction-driven brine and/or saltwater flow at deep locations and its influence on (a) tracer concentrations observed in shallow sediments, (b) build up of fluid overpressure, (c) hydrocarbon generation and migration, (d) subsidence due to groundwater and/or hydrocarbons withdrawal, and (e) formation of ore deposits. Main processes driving the diagenesis of sediments after deposition are mechanical compaction due to overburden and precipitation/dissolution associated with reactive transport. The natural evolution of sedimentary basins is characterized by geological time scales, thus preventing direct and exhaustive measurement of the system dynamical changes. The outputs of compaction models are plagued by uncertainty because of the incomplete knowledge of the models and parameters governing diagenesis. Development of robust methodologies for inverse modeling and parameter estimation under uncertainty is therefore crucial to the quantification of natural compaction phenomena. We employ a numerical methodology based on three building blocks: (i) space-time discretization of the compaction process; (ii) representation of target output variables through a Polynomial Chaos Expansion (PCE); and (iii) model

  8. Thermal history determined by fission-track dating for three sedimentary basins in California and Wyoming

    USGS Publications Warehouse

    Naeser, Nancy D.

    1984-01-01

    The use of fission-tracks is demonstrated in studies of time-temperature relationships in three sedimentary basins in the western United States; in the Tejon Oil Field area of the southern San Joaquin Valley, California; in the northeastern Green River basin, Wyoming, and in drill holes in the southern Powder River Basin, Wyoming.

  9. Looking for sedimentary basins using global gravity and crustal models

    NASA Astrophysics Data System (ADS)

    Colpani, Stefano; Strykowski, Gabriel

    2014-05-01

    Publically available and newly released global crustal model, CRUST 1.0 (Laske et al., 2013) in combination with satellite based global gravity models GOCO3s (Mayer-Gürr T. et al., 2012) yield a possibility of combining global source models with global gravity models. The depths to the top and to the base of the geological units obtained from the global crust model are used to fix the source geometry. This information is subsequently used to forward compute the global gravity signature of these units in different heights above the sources and for unit mass density. The average global mass density for the geological unit acts like a scaling factor and the relation to the gravity signal becomes linear. The computations are done both for Tz (gravity disturbances) and for some chosen gravity gradient components Tzz, Tzx and Tzy, where x,y and z refer to a local east-north-up Cartesian reference frame. The above setup allows constructing a model of the regional (gravity) field both for Tz and for the above gradient components Tzz, Tzx and Tzy and to improve it on regional scale. In principle, the method allows to keep track of the relation between the regional (gravity) signal and the source model. Subsequently, a generalized Nettleton's method can be used to fine-tune density values for the sediments from any above type of gravity data and a combination of it. Finally, for the well-surveyed areas, the results can be compared with the independent information about the basin geometry. This experience can be used for quantifying the information about the sedimentary basin in areas where the information is limited.

  10. Noise correlation tomography of Southwest Western Canada Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Gu, Yu Jeffrey; Shen, Luyi

    2015-07-01

    We analyse continuous recordings from 23 broadband seismic stations near Alberta, the southwestern sector of the Western Canada Sedimentary Basin. Noise correlation tomo-graphy based on vertical-component seismograms reveals below-average shear velocities at shallow and middle crustal depths in central Alberta, spanning across Proterozoic accreted terranes and Archean microcontinents. This observation likely results from extensive plate convergence and crustal melting during the Proterozoic eon. The overall correlation between the crustal velocities and presumed basement domains is lower than expected, however. In the lower crust, the main pattern of shear velocities is relatively concordant with the reported domain boundaries and key Precambrian structures appear to be intact. The shear velocities beneath the Loverna Block, the largest constituent of the Hearne craton, are 10 per cent higher than the regional average. This prominent northeast striking seismic anomaly is moderately correlated with the regional heat flow and potentially represents the remnant core of the Archean Hearne province. The associated high velocities extend into the western part of the Medicine Hat Block, a possible Archean microcontinent with a debatable origin, and contribute to a strong east-west structural gradient in the lower crust. The presence and the continuity of this anomalous structure imply extensive communications among the various basement domains in southern Alberta during the assembly of the North American continent.

  11. The potential for free and mixed convection in sedimentary basins

    USGS Publications Warehouse

    Raffensperger, J.P.; Vlassopoulos, D.

    1999-01-01

    Free thermal convection and mixed convection are considered as potential mechanisms for mass and heat transport in sedimentary basins. Mixed convection occurs when horizontal flows (forced convection) are superimposed on thermally driven flows. In cross section, mixed convection is characterized by convection cells that migrate laterally in the direction of forced convective flow. Two-dimensional finite-element simulations of variable-density groundwater flow and heat transport in a horizontal porous layer were performed to determine critical mean Rayleigh numbers for the onset of free convection, using both isothermal and semi-conductive boundaries. Additional simulations imposed a varying lateral fluid flux on the free-convection pattern. Results from these experiments indicate that forced convection becomes dominant, completely eliminating buoyancy-driven circulation, when the total forced-convection fluid flux exceeds the total flux possible due to free convection. Calculations of the thermal rock alteration index (RAI=q????T) delineate the patterns of potential diagenesis produced by fluid movement through temperature gradients. Free convection produces a distinct pattern of alternating positive and negative RAIs, whereas mixed convection produces a simpler layering of positive and negative values and in general less diagenetic alteration. ?? Springer-Verlag.

  12. Understanding Long-Term Solute Transport in Sedimentary Basins: Simulating Brine Migration in the Alberta Basin. Final Report

    SciTech Connect

    Alicia M. Wilson

    2009-11-30

    Mass transport in deep sedimentary basins places important controls on ore formation, petroleum migration, CO2 sequestration, and geochemical reactions that affect petroleum reservoir quality, but large-scale transport in this type of setting remains poorly understood. This lack of knowledge is highlighted in the resource-rich Alberta Basin, where geochemical and hydrogeologic studies have suggested residence times ranging from hundreds of millions of years to less than 5 My, respectively. Here we developed new hydrogeologic models that were constrained by geochemical observations to reconcile these two very different estimates. The models account for variable-density fluid flow, heat transport, solute transport, sediment deposition and erosion, sediment compressibility, and dissolution of salt deposits, including Cl/Br systematics. Prior interpretations of Cl/Br ratios in the Alberta Basin concluded that the brines were derived from evaporatively-concentrated brines that were subsequently diluted by seawater and freshwater; models presented here show that halite dissolution must have contributed strongly as well, which implies significantly greater rates of mass transport. This result confirms that Cl/Br ratios are subject to significant non-uniqueness and thus do not provide good independent indicators of the origin of brines. Salinity and Cl/Br ratios provided valuable new constraints for basin-scale models, however. Sensitivity studies revealed that permeabilities obtained from core- and field-scale tests were appropriate for basin-scale models, despite the differences in scale between the tests and the models. Simulations of groundwater age show that the residence time of porefluids in much of the basin is less than 100 My. Groundwater age increases with depth and approaches 200 My in the deepest part of the basin, but brines are significantly younger than their host rocks throughout the basin.

  13. Space Station Views of African Sedimentary Basins-Analogs for Subsurface Patterns

    NASA Technical Reports Server (NTRS)

    Wilkinson, M. Justin

    2007-01-01

    Views of African sedimentary basins from the International Space Station (ISS) is presented. The images from ISS include: 1) Inland deltas; 2) Prediction; 3) Significance; 4) Exploration applications; and 5) Coastal megafans

  14. Characterizing long period (1--10 sec) ground motions for base isolated structures located in sedimentary basins

    SciTech Connect

    Graves, R.W.; Somerville, P.G.

    1995-12-01

    Many urban regions, including Los Angeles, Portland and Seattle in the United States and Tokyo in Japan, are located above deep sedimentary basins. The conventional approach of estimating ground motions in these environments is to assume that the geology can be characterized by a horizontally stratified medium, and that only the shallowest few tens of meters influence the ground motion characteristics. However, the trapping and amplification of long period (1-10 sec) waves by sedimentary basins can generate amplitudes that are significantly larger than those calculated from simple 1D models of site resonance. This may be of particular concern for base isolated structures which are most sensitive to ground motions in this period range. The recent development of efficient computational methods for modeling seismic wave, propagation in laterally varying geological structure enable the authors to model the effects of sedimentary basins on earthquake generated ground motions. They are now applying this calculation procedure to characterize the ground motions that may be generated in the Puget Trough and the Portland Basin due to large earthquakes on the Cascadia subduction zone, and in the Los Angeles region due to large earthquakes on blind thrust faults beneath the Los Angeles basin.

  15. Tectono-Sedimentary Analysis of Rift Basins: Insights from the Corinth Rift, Greece

    NASA Astrophysics Data System (ADS)

    Gawthorpe, Robert; Ford, Mary

    2015-04-01

    Existing models for the tectono-sedimentary evolution of rift basins are strongly linked the growth and linkage of normal fault segments and localization of fault activity. Early stages of faulting (rift initiation phase) are characterized by distributed, short, low displacement fault segments, subdued fault-related topography and small depocentres within which sedimentation keeps pace with subsidence. Following linkage and displacement localization (rift climax phase), deformation if focused onto major, crustal-scale fault zones with kilometre-scale displacement. These major faults generate pronounced tilted fault-block topography, with subsidence rates that outpace sedimentation causing a pronounced change to deep-water deposition. Such models have been successful in helping to understand the gross structural and sedimentary evolution of rift basins, but recent work has suggested that pre-existing structures, normal fault interaction with pre-rift salt and antecedent drainage systems significantly alter this initiation-to-climax perspective of rift basin development. The E-W-striking, Pliocene-Pleistocene Corinth rift, central Greece, is an excellent natural laboratory for studying the tectono-sedimentary evolution of rift basins due to its young age, excellent onshore exposure of syn-rift structure and stratigraphy and extensive offshore seismic data. The rift cuts across the NW-SE-striking Hellenide mountain belt and has migrated northward and westward during its evolution. The Hellenide mountain belt significantly influences topography and drainage in the west of the rift. High topography and large antecedent drainage systems, focused along palaeovalleys, provided high sediment flux to NE-flowing alluvial systems that overfilled early-rift depocentres. Further east, away from the main antecedent drainage networks, contemporaneous deposits comprise deep-lacustrine turbidite channel and lobe complexes and basinal marls. Thus the stratigraphic expression within

  16. 3D Inversion of Gravity Anomalies for the Interpretation of Sedimentary Basins using Variable Density Contrast

    NASA Astrophysics Data System (ADS)

    Ekinci, Yunus Levent; Ertekin, Can

    2015-04-01

    Concern about sedimentary basins is generally related to their genetic and economic significance. Analysis of sedimentary basins requires the acquisition of data through outcrop studies and subsurface investigations that encompass drilling and geophysics. These data are commonly analysed by computer-assisted techniques. One of these methods is based on analysing gravity anomalies to compute the depth of sedimentary basin-basement rock interface. Sedimentary basins produce negative gravity anomalies, because they have mostly lower densities than that of the surrounding basement rocks. Density variations in a sedimentary fill increase rapidly at shallower depths then gradually reach the density of surrounding basement rocks due to the geostatic pressure i.e. compaction. The decrease of the density contrast can be easily estimated by a quadratic function. Hence, if the densities are chosen properly and the regional background is removed correctly, the topographical relief of the sedimentary basin-basement rock interface might be estimated by the inversion of the gravity data using an exponential density-depth relation. Three dimensional forward modelling procedure can be carried out by introducing a Cartesian coordinate system, and placing vertical prisms just below observation points on the grid plane. Depth to the basement, namely depths to the bottom of the vertical prisms are adjusted in an iterative manner by minimizing the differences between measured and calculated residual gravity anomalies. In this study, we present a MATLAB-based inversion code for the interpretation of sedimentary basins by approximating the topographical relief of sedimentary basin-basement rock interfaces. For a given gridded residual gravity anomaly map, the procedure estimates the bottom depths of vertical prisms by considering some published formulas and assumptions. The utility of the developed inversion code was successfully tested on theoretically produced gridded gravity data set

  17. Deciphering the geochemical and mineralogical changes of a Miocene sedimentary basin infill, Mendoza Province, Argentina

    NASA Astrophysics Data System (ADS)

    Hunger, Gabriel; Moscariello, Andrea; Ventra, Dario

    2017-04-01

    Sediments deposited in foreland basins are accurate recorders of processes acting at different temporal and spatial scales during orogenic uplift. The effects of allogenic forcing on foreland sedimentation are well known at basin-scale, but uncertainties remain in deciphering and interpreting them at higher resolution, and in differentiating them from the sedimentary changes due to autogenic processes. We present observations on the continental sedimentology and stratigraphy of the Central Argentinian Foreland. The majority of the basin infill is comprised by the Mariño Fm. and La Pilona Fm., which were deposited during the Miocene and cover almost 2000 m of stratigraphy. The large scale stratigraphy trend leads to interpret the entire alluvial system as a large fluvial fan that prograded over the proximal margin of the foreland basin. The basin infill records a continuous sediment supply from the rising Principal Cordillera and the first stages of the uplift of the Frontal Cordillera. The interaction of different allogenic forcing factors, but also autogenic processes, is recorded in the compositional changes of the sedimentary infill. This project aims to provide a detailed reconstruction of paleoenvironmental dynamics and unravel the relative roles of climate and tectonics, using a high-resolution, integrated compositional and sedimentological analysis of the Mariño Formation and the basal part of the La Pilona Formation. The followed approach embodies the use of automated QEMSCAN technology, geochemistry, heavy-minerals and radiogenic isotope analysis. Along 1500 m of stratigraphy we recognize compositional variations related to the evolution of the basin infill due to, at least, 5 phases of non-steady state conditions. Principal component analysis done with the major elements, main mineral phases and heavy minerals allow us to recognize the importance of the weathering and diagenesis in the total compositional variability. The A-CN-K ternary diagram displays

  18. The effect of sedimentary basins on surface waves that pass through them

    NASA Astrophysics Data System (ADS)

    Feng, Lili; Ritzwoller, Michael H.

    2017-10-01

    Surface waves propagating through sedimentary basins undergo elastic wavefield complications that include multiple scattering, amplification, the formation of secondary wave fronts and subsequent wave front healing. Unless these effects are accounted for accurately, they may introduce systematic bias to estimates of source characteristics, the inference of the anelastic structure of the Earth, and ground motion predictions for hazard assessment. Most studies of the effects of basins on surface waves have centred on waves inside the basins. In contrast, the purpose of this paper is to investigate wavefield effects downstream from sedimentary basins, with particular emphasis on continental basins and propagation paths, elastic structural heterogeneity and Rayleigh waves at 10 s period. Based on wavefield simulations through a recent 3-D crustal and upper-mantle model of East Asia, we demonstrate significant Rayleigh wave amplification downstream from sedimentary basins in eastern China such that Ms measurements made on the simulated wavefield vary by more than a magnitude unit. We show that surface wave amplification caused by basins results predominantly from elastic focusing and that amplification effects produced through 3-D basin models are reproduced using 2-D membrane wave simulations through an appropriately defined phase velocity map. The principal characteristics of elastic focusing in both 2-D and 3-D simulations include (1) retardation of the wave front inside the basins; (2) deflection of the wave propagation direction; (3) formation of a high-amplitude lineation directly downstream from the basin bracketed by two low-amplitude zones and (4) formation of a secondary wave front. We illustrate with several examples how the size and geometry of the basin affects focusing. Finally, by comparing the impact of elastic focusing with anelastic attenuation, we argue that on-continent sedimentary basins are expected to affect surface wave amplitudes more strongly

  19. Large Double-ringed Basin

    NASA Image and Video Library

    2000-08-05

    Taken about 40 minutes before NASA Mariner 10 made its close approach to Mercury on Sept. 21,1974, this picture shows a large double-ringed basin center of picture located in the planet south polar region

  20. Modes of sedimentary basin formation in the north-eastern Black Sea

    NASA Astrophysics Data System (ADS)

    Stephenson, Randell; Starostenko, Vitaly; Sydorenko, Grygoriy; Yegorova, Tamara

    2016-04-01

    The Greater Caucasus and Black Sea sedimentary basins developed in a Mesozoic back-arc setting, the former older than the latter (Jurassic v. Cretaceous). Compressional shortening of the former and accompanying ongoing development of marginal basin depocentres in the north-eastern Black Sea - which is closely tied to the formation of the Crimea-Greater Caucasus orogen - is a Cenozoic phenomenon, starting in the Eocene and proceeding until the present day. Recently, the sedimentary basin/crust/lithosphere geometry of the study area has been characterised across a range of scales using regional seismic reflection profiling, long-offset refraction/wide-angle reflection profiling and local earthquake tomography. These provide a new integrated image of the present-day crustal structure and sedimentary basin architecture of the northern margin of the eastern Black Sea, north across the Azov Sea and provide evidence of the deeper expression of sedimentary basins and the processes controlling the geometry of their inversion during the Cenozoic. It is inferred that the Greater Caucasus paleo-Basin, lying stratigraphically below the Black Sea and younger sedimentary successions, extends further to the west than previously known. This basin has significant thickness in the area between the Azov and Black seas and probably forms the deeper core of the Crimea-Caucasus inversion zone. The Crimea-Greater Caucasus orogenic belt is the expression of "basin inversion" of the Jurassic Greater Caucasus paleo-Basin, the degree of inversion of which varies along strike. The Greater Caucasus foredeep basins - Indolo-Kuban and Sorokin-Tuapse troughs -represent syn-inversional marginal troughs to the main inversion zone. The Shatsky Ridge - the northern flank of the main East Black Sea Basin - may also be mainly a syn-inversional structure, underlain by a blind thrust zone expressed as a northward dipping zone of seismicity on the northern margin of the eastern Black Sea.

  1. Lithospheric flexure and sedimentary basin evolution: depositional cycles in the steer's head model

    NASA Astrophysics Data System (ADS)

    Moore, James; Watts, Tony

    2016-04-01

    Backstripping studies of biostratigraphic data from deep wells show that sediment loading is one of the main factors controlling the subsidence and uplift history of sedimentary basins. Previous studies based on single layer models of elastic and viscoelastic plates overlying an inviscid fluid have shown that sediment loading, together with a tectonic subsidence that decreases exponentially with time, can explain the large-scale 'architecture' of rift-type basins and, in some cases, details of their internal stratigraphy such as onlap and offlap patterns. One problem with these so-called 'steer's head' models is that they were based on a simple rheological model in which the long-term strength of the lithosphere increased with thermal age. Recent oceanic flexure studies, however, reveal that the long-term strength of the lithosphere depends not only on thermal age, but also load age. We have used the thermal structure based on plate cooling models, together with recent experimentally-derived flow laws, to compute the viscosity structure of the lithosphere and a new analytical model to compute the flexure of a multilayer viscoelastic plate by a trapezoid-shaped sediment load at different times since basin initiation. The combination of basin subsidence and viscoelastic flexural response results in the fluctuation of the depositional surface with time. If we define the nondimensional number Dw= τm/τt, where τm is the Maxwell time constant and τt is the thermal time constant, we find that for Dw<<1 the flexure approximates that of an elastic plate and is dominated by "onlapping" stratigraphy which evolves through the sedimentary facies with a progressive deepening of the depositional surface. For Dw>>1 the flexure approximates that of a viscoelastic plate and is dominated by "offlapping" stratigraphy, with the basin edges evolving through shallow marine facies; though erosion late in the basin formation prevents much of this from being recorded in the stratigraphy

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

    NASA Astrophysics Data System (ADS)

    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

  3. Tectono-sedimentary history of the Early Liassic basins of the Central High Atlas (Morocco)

    NASA Astrophysics Data System (ADS)

    Quiquerez, A.; Allemand, P.; Sarih, S.; Garcia, J.-P.

    2012-04-01

    The timing of the opening of the Central High Atlas basins (Morocco) is still debated. Previous works have proposed that the tectonics which started in the Triassic was polyphased and that the Early Liassic was characterized by thermal subsidence before a new phase of extension at the beginning of the Toarcian. In order to precise the timing during the Early Liassic, we have documented a syn-rift succession, in the hanging wall of normal fault segment along a 75 km-long transect (Tizi n' Firest fault). Deposits are composed of massive limestones alternating with marl and gravity-flow related deposits. Field observations have been performed on six sections, 5 to 40 km apart. They include both the description of large-scale architecture from satellite image analysis, the identification of carbonate facies from thin sections, the measurements of sediment transport direction, and also the determination of nine time-lines dated by biochronological markers, from the Sinemurian to the Domerian. This fine chronostratigraphic framework has permitted to delineate and correlate 9 stratigraphical units in 6 sites from the Sinemurian to the Domerian. The reconstructions of detailed temporal and spatial sedimentary patterns along the fault have highlighted a high variability of the syn-rift stratigraphy along the normal fault segments. Two main sub-basins have been defined along this transect. The geometry provided by the time-lines showed that the depocenter were located firstly in the west sub-basin, up to the Carixian, and later in the east sub-basin. The central area remained a low preservation domain during the Early Liassic. Most of the transport directions measured is oriented toward the north, indicating the existence of an active topography on the southern limit of the basin at that time. However, some measurements are oriented toward the east, and this mainly during Domerian, possibly indicating slopes orientated in that direction, suggesting asymmetric fault geometry

  4. The tectonic development and erosion of the Knox Subglacial Sedimentary Basin, East Antarctica

    NASA Astrophysics Data System (ADS)

    Maritati, A.; Aitken, A. R. A.; Young, D. A.; Roberts, J. L.; Blankenship, D. D.; Siegert, M. J.

    2016-10-01

    Sedimentary basins beneath the East Antarctic Ice Sheet (EAIS) have immense potential to inform models of the tectonic evolution of East Antarctica and its ice-sheet. However, even basic characteristics such as thickness and extent are often unknown. Using airborne geophysical data, we resolve the tectonic architecture of the Knox Subglacial Sedimentary Basin in western Wilkes Land. In addition, we apply an erosion restoration model to reconstruct the original basin geometry for which we resolve geometry typical of a transtensional pull-apart basin. The tectonic architecture strongly indicates formation as a consequence of the rifting of India from East Gondwana from ca. 160-130 Ma, and we suggest a spatial link with the western Mentelle Basin offshore Western Australia. The erosion restoration model shows that erosion is confined within the rift margins, suggesting that rift structure has strongly influenced the evolution of the Denman and Scott ice streams.

  5. Application of MSS/LANDSAT images to the structural study of recent sedimentary areas: Campos Sedimentary Basin, Rio de Janeiro, Brazil

    NASA Technical Reports Server (NTRS)

    Parada, N. D. J. (Principal Investigator); Barbosa, M. P.

    1983-01-01

    Visual and computer aided interpretation of MSS/LANDSAT data identified linear and circular features which represent the ""reflexes'' of the crystalline basement structures in the Cenozoic sediments of the emergent part of the Campos Sedimentary Basin.

  6. Estimate of the Geothermal Energy Resource in the Major Sedimentary Basins in the United States (Presentation)

    SciTech Connect

    Esposito, A.; Porro, C.; Augustine, C.; Roberts, B.

    2012-09-01

    Because most sedimentary basins have been explored for oil and gas, well logs, temperatures at depth, and reservoir properties such as depth to basement and formation thickness are well known. The availability of this data reduces exploration risk and allows development of geologic exploration models for each basin. This study estimates the magnitude of recoverable geothermal energy from 15 major known U.S. sedimentary basins and ranks these basins relative to their potential. The total available thermal resource for each basin was estimated using the volumetric heat-in-place method originally proposed by (Muffler, 1979). A qualitative recovery factor was determined for each basin based on data on flow volume, hydrothermal recharge, and vertical and horizontal permeability. Total sedimentary thickness maps, stratigraphic columns, cross sections, and temperature gradient information was gathered for each basin from published articles, USGS reports, and state geological survey reports. When published data were insufficient, thermal gradients and reservoir properties were derived from oil and gas well logs obtained on oil and gas commission databases. Basin stratigraphy, structural history, and groundwater circulation patterns were studied in order to develop a model that estimates resource size, temperature distribution, and a probable quantitative recovery factor.

  7. Regional-scale analysis of the geothermal regime in the western Canada sedimentary basin

    SciTech Connect

    Bachu, S. ); Burwash, R.A. )

    1991-01-01

    This paper reports that radiogenic heat generation at the top of the crystalline Precambrian basement underneath the Western Canada Sedimentary Basin is highly variable, on average higher than for the exposed Canadian Shield, and reflects the basement tectonic structure. The areal distribution of the geothermal gradient across the sediments shows a regional-scale northerly increase, with intermediate- and local-state features correlating with anomalies in heat generation at the top of the basement. Only in the northeast and southeast corners of the basin can high geothermal gradients not be explained by heat generation; there they may be caused by convective fluid flow effects. The temperature distribution at the base of the sediments is highly correlated with the thickness of the sedimentary cover and reflects major topographic and basement features. Overall, the characteristics of the geothermal regime in the Western Canada Sedimentary Basin are indicative of a conduction dominated system.

  8. Evolution of fore-arc and back-arc sedimentary basins with focus on the Japan subduction system and its analogues

    NASA Astrophysics Data System (ADS)

    Sato, Hiroshi; Ishiyama, Tatsuya; Matenco, Liviu; Nader, Fadi Henri

    2017-07-01

    The International Lithosphere Program (ILP) seeks to elucidate the nature, dynamics, origin and evolution of the lithosphere through international, multidisciplinary geoscience research projects and coordinating committees (Cloetingh and Negendank, 2010). The focus of the Task Force VI Sedimentary Basins activities is to foster collaborations between academia, research institutes and industry in all domains relevant for the understanding of sedimentary basins, from regional to nano-scale, from the deep earth to near surface processes (e.g., Roure et al., 2010, 2013). In this activity, it is important to develop and validate novel concepts of sedimentary basin evolution and topography building by incorporating geological/geophysical datasets and methodologies applied to worldwide natural laboratories (Cloetingh et al., 2011; Cloetingh and Willett, 2013; Matenco and Andriessen, 2013). The Task Force aims to understand and predict the processes that control the formation and evolution of the coupled orogens and sedimentary basins system through integration of field studies, analytical techniques and numerical/analogue modelling. At the same time, the Task Force aims to promote research in the domain of sedimentary basins evolution and quantitative tectonics for the study of mountain building and the subsequent extensional collapse, and their quantitative implications for vertical motions on different temporal and spatial scales (Gibson et al., 2015; Matenco et al., 2016; Roure, 2008; Seranne et al., 2015). The implications of tectonics on basin fluids (fluid-flow and rock-fluid interactions) are important to understand and predict geo-resources (e.g., Nader, 2016). Important is to initiate innovative research lines in linking the evolution of sedimentary systems by integrating cross-disciplinary expertise with a focus on integrated sedimentary basins and orogenic evolution. The key is to strengthen the synergy between academic research and applied industry in large

  9. Formation Conditions and Sedimentary Characteristics of a Triassic Shallow Water Braided Delta in the Yanchang Formation, Southwest Ordos Basin, China

    PubMed Central

    Liu, Ziliang; Shen, Fang; Zhu, Xiaomin; Li, Fengjie; Tan, Mengqi

    2015-01-01

    A large, shallow braided river delta sedimentary system developed in the Yanchang Formation during the Triassic in the southwest of the Ordos basin. In this braided delta system, abundant oil and gas resources have been observed, and the area is a hotspot for oil and gas resource exploration. Through extensive field work on outcrops and cores and analyses of geophysical data, it was determined that developments in the Late Triassic produced favorable geological conditions for the development of shallow water braided river deltas. Such conditions included a large basin, flat terrain, and wide and shallow water areas; wet and dry cyclical climate changes; ancient water turbulence; dramatic depth cycle changes; ancient uplift development; strong weathering of parent rock; and abundant supply. The shallow water braided river delta showed grain sediment granularity, plastic debris, and sediment with mature composition and structure that reflected the strong hydrodynamic environment of large tabular cross-bedding, wedge cross-bedding, and multiple positive rhythms superimposed to form a thick sand body layer. The branch river bifurcation developed underwater, and the thickness of the sand body increased further, indicating that the slope was slow and located in shallow water. The seismic responses of the braided river delta reflected strong shallow water performance, indicated by a progradation seismic reflection phase axis that was relatively flat; in addition, the seismic reflection amplitude was strong and continuous with a low angle and extended over considerable distances (up to 50 km). The sedimentary center was close to the provenance, the width of the river was large, and a shallow sedimentary structure and a sedimentary rhythm were developed. The development of the delta was primarily controlled by tectonic activity and changes in the lake level; as a result, the river delta sedimentary system eventually presented a “small plain, big front” character. PMID

  10. Formation Conditions and Sedimentary Characteristics of a Triassic Shallow Water Braided Delta in the Yanchang Formation, Southwest Ordos Basin, China.

    PubMed

    Liu, Ziliang; Shen, Fang; Zhu, Xiaomin; Li, Fengjie; Tan, Mengqi

    2015-01-01

    A large, shallow braided river delta sedimentary system developed in the Yanchang Formation during the Triassic in the southwest of the Ordos basin. In this braided delta system, abundant oil and gas resources have been observed, and the area is a hotspot for oil and gas resource exploration. Through extensive field work on outcrops and cores and analyses of geophysical data, it was determined that developments in the Late Triassic produced favorable geological conditions for the development of shallow water braided river deltas. Such conditions included a large basin, flat terrain, and wide and shallow water areas; wet and dry cyclical climate changes; ancient water turbulence; dramatic depth cycle changes; ancient uplift development; strong weathering of parent rock; and abundant supply. The shallow water braided river delta showed grain sediment granularity, plastic debris, and sediment with mature composition and structure that reflected the strong hydrodynamic environment of large tabular cross-bedding, wedge cross-bedding, and multiple positive rhythms superimposed to form a thick sand body layer. The branch river bifurcation developed underwater, and the thickness of the sand body increased further, indicating that the slope was slow and located in shallow water. The seismic responses of the braided river delta reflected strong shallow water performance, indicated by a progradation seismic reflection phase axis that was relatively flat; in addition, the seismic reflection amplitude was strong and continuous with a low angle and extended over considerable distances (up to 50 km). The sedimentary center was close to the provenance, the width of the river was large, and a shallow sedimentary structure and a sedimentary rhythm were developed. The development of the delta was primarily controlled by tectonic activity and changes in the lake level; as a result, the river delta sedimentary system eventually presented a "small plain, big front" character.

  11. The amplitude effects of sedimentary basins on through-passing surface waves

    NASA Astrophysics Data System (ADS)

    Feng, L.; Ritzwoller, M. H.; Pasyanos, M.

    2016-12-01

    Understanding the effect of sedimentary basins on through-passing surface waves is essential in many aspects of seismology, including the estimation of the magnitude of natural and anthropogenic events, the study of the attenuation properties of Earth's interior, and the analysis of ground motion as part of seismic hazard assessment. In particular, knowledge of the physical causes of amplitude variations is important in the application of the Ms:mb discriminant of nuclear monitoring. Our work addresses two principal questions, both in the period range between 10 s and 20 s. The first question is: In what respects can surface wave propagation through 3D structures be simulated as 2D membrane waves? This question is motivated by our belief that surface wave amplitude effects down-stream from sedimentary basins result predominantly from elastic focusing and defocusing, which we understand as analogous to the effect of a lens. To the extent that this understanding is correct, 2D membrane waves will approximately capture the amplitude effects of focusing and defocusing. We address this question by applying the 3D simulation code SW4 (a node-based finite-difference code for 3D seismic wave simulation) and the 2D code SPECFEM2D (a spectral element code for 2D seismic wave simulation). Our results show that for surface waves propagating downstream from 3D sedimentary basins, amplitude effects are mostly caused by elastic focusing and defocusing which is modeled accurately as a 2D effect. However, if the epicentral distance is small, higher modes may contaminate the fundamental mode, which may result in large errors in the 2D membrane wave approximation. The second question is: Are observations of amplitude variations across East Asia following North Korean nuclear tests consistent with simulations of amplitude variations caused by elastic focusing/defocusing through a crustal reference model of China (Shen et al., A seismic reference model for the crust and uppermost

  12. Paleogeographic and paleotectonic setting of sedimentary basins in the Sevier thrust belt and hinterland, eastern Great Basin

    SciTech Connect

    Schmitt, J.G. . Dept. of Earth Sciences); Vandervoort, D.S. . Dept. of Geological Sciences); Suydam, J.D. . Dept. of Geology)

    1993-04-01

    The eastern Great Basin contains a sparse record of broadly distributed Cretaceous sedimentary rocks which record: evolution of intermontane basins during development of the Sevier (Sv)contractional orogen and incipient extensional collapse of the elevated Sv hinterland (east-central NV), and complex tectono-sedimentary interactions between frontal thrust belt structures and the western margin of the adjacent foreland basin. Palinspastic restoration of these strata and associated structures to pre-Tertiary extension positions reveals a clearer pictures of Cretaceous basin paleogeography and allows comparison with the Puna/Altiplano plateau and precordillera thrust belt of the Neogene Andean orogen. Two syntectonic stratal assemblages are present in east-central NV. Lower Cretaceous alluvial strata (Newark Canyon Fm) record basin development coeval with emergence of contractional structures in the Sv hinterland. Localized early Cretaceous basins were possibly piggyback immature; periods of open drainage to the to the east and south suggest connection with the nascent Sv foreland basin to the east (Cedar Mountain/Sanpete Fms) prior to major thrust loading in central Utah. Development of hinterland structures is almost recorded by Aptian-Albian foreland basin alluvial deposits in SW Utah (Dakota Fm) and southern Nevada (Willow Tank Fm). Upper Cretaceous to Eocene strata (Sheep Pass Fm) record inception of regionally abundant alluvial-lacustrine basins which developed in response to onset of latest Cretaceous extension and associated collapse of the Sv hinterland. Evolution of the structurally complex western margin of the Sv foreland basin is recorded in Cretaceous through Eocene strata deposited in: piggyback basins which were at times hydrologically connected to the adjacent foreland basins, and thrust-proximal portions of the foreland basin. These proximal areas are characterized by folding and faulting of basin fill and development of intrabasinal unconformities.

  13. Estimate of Geothermal Energy Resource in Major U.S. Sedimentary Basins (Presentation)

    SciTech Connect

    Porro, C.; Augustine, C.

    2012-04-01

    This study estimates the magnitude of geothermal energy from fifteen major known US sedimentary basins and ranks these basins relative to their potential. Because most sedimentary basins have been explored for oil and gas, well logs, temperatures at depth, and reservoir properties are known. This reduces exploration risk and allows development of geologic exploration models for each basin as well as a relative assessment of geologic risk elements for each play. The total available thermal resource for each basin was estimated using the volumetric heat-in-place method originally proposed by Muffler (USGS). Total sedimentary thickness maps, stratigraphic columns, cross sections, and temperature gradient Information were gathered for each basin from published articles, USGS reports, and state geological survey reports. When published data was insufficient, thermal gradients and reservoir properties were derived from oil and gas well logs obtained on oil and gas commission websites. Basin stratigraphy, structural history, and groundwater circulation patterns were studied in order to develop a model that estimates resource size and temperature distribution, and to qualitatively assess reservoir productivity.

  14. Diachronous uplift and recycling of sedimentary basins during Cenozoic tectonic transpression, northeastern Caribbean plate margin

    NASA Astrophysics Data System (ADS)

    Heubeck, Christoph; Mann, Paul; Dolan, James; Monechi, Simonetta

    1991-02-01

    Four marine sedimentary sequences of Late Cretaceous to Pleistocene age crop out in the 320 km long, 1 to 30 km wide Peralta-Rio Ocoa belt of Hispaniola (Haiti and Dominican Republic). The four sedimentary sequences are dominated by marine turbiditic rocks ranging up to 11.5 km in apparent thickness and exhibit mainly northwest to southeast, belt-parallel paleocurrents. The three younger sequences are generally in fault or unconformable contact with the underlying sequence. From northwest to southeast, the four belts become progressively wider, younger, less metamorphosed, less folded and faulted, and lower in topographic elevation. We interpret the three younger sequences as a syn-tectonic stratigraphic record of diachronous, northwest to southeast transpressional closure of a Coniacian-Danian back-arc basin represented by the oldest exposed sedimentary sequence at the northwest end of the belt and inferred at depth beneath the three younger sequences. Using the stratigraphic record, we infer the following three stages in the closure of the back-arc basin and the overlying younger basins. Stage One: latest Cretaceous to early Late Eocene closure. A minimum of 11 km of Paleocene turbidites and limestone in the Padre las Casas area and a minimum of 11.5 km of Early Eocene to early Late Eocene pelagic limestone, mudstone, sandstone, and siltstone in the Peralta and Sierra El Numero areas was deposited in an elongate basin derived from the first stage of latest Cretaceous-early Late Eocene closure and erosion of the Coniacian-Danian back-arc basin to the northwest. Paleocene-Eocene turbidites in both areas contain large amounts of reworked Campanian-Paleocene microfauna and exhibit northwest to southeast belt-parallel paleocurrents. Syn-deformational features in Eocene sedimentary rocks in the Peralta and Sierra El Numero area indicate that convergent deformation accompanied sedimentation (Witschard and Dolan, 1990). Stage Two: Middle Eocene to Early Miocene closure

  15. Derivation of S and Pb in phanerozoic intrusion-related metal deposits from neoproterozoic sedimentary pyrite, Great Basin, United States

    USGS Publications Warehouse

    Vikre, P.G.; Poulson, S.R.; Koenig, A.E.

    2011-01-01

    from sedimentary pyrite, and volatiles acquired from deeper crustal or mantle sources. In the central and eastern Great Basin, the wide distribution and high density of small to mid-sized vein, replacement, and skarn intrusion-related metal deposits in lower Paleozoic rocks that contain TDS sedimentary pyrite S and Pb reflect (1) prolific Jurassic, Cretaceous, and Tertiary magmatism, (2) a regional, substrate reservoir of S and Pb in permeable and homogeneous siliciclastic strata, and (3) relatively small scale concentration of substrate and magmatic components. Large intrusion-related metal deposits in the central and eastern Great Basin acquired S and most Pb from thicker lithospheric sections. ?? 2011 Society of Economic Geologists, Inc.

  16. Atmospheric methane from organic carbon mobilization in sedimentary basins — The sleeping giant?

    NASA Astrophysics Data System (ADS)

    Kroeger, K. F.; di Primio, R.; Horsfield, B.

    2011-08-01

    The mass of organic carbon in sedimentary basins amounts to a staggering 10 16 t, dwarfing the mass contained in coal, oil, gas and all living systems by ten thousand-fold. The evolution of this giant mass during subsidence and uplift, via chemical, physical and biological processes, not only controls fossil energy resource occurrence worldwide, but also has the capacity for driving global climate: only a tiny change in the degree of leakage, particularly if focused through the hydrate cycle, can result in globally significant greenhouse gas emissions. To date, neither climate models nor atmospheric CO 2 budget estimates have quantitatively included methane from thermal or microbial cracking of sedimentary organic matter deep in sedimentary basins. Recent estimates of average low latitude Eocene surface temperatures beyond 30 °C require extreme levels of atmospheric CO 2. Methane degassing from sedimentary basins may be a mechanism to explain increases of atmospheric CO 2 to values as much as 20 times higher than pre-industrial values. Increased natural gas emission could have been set in motion either by global tectonic processes such as pulses of activity in the global alpine fold belt, leading to increased basin subsidence and maturation rates in the prolific Jurassic and Cretaceous organic-rich sediments, or by increased magmatic activity such as observed in the northern Atlantic around the Paleocene-Eocene boundary. Increased natural gas emission would have led to global warming that was accentuated by long lasting positive feedback effects through temperature transfer from the surface into sedimentary basins. Massive gas hydrate dissociation may have been an additional positive feedback factor during hyperthermals superimposed on long term warming, such as the Paleocene-Eocene Thermal Maximum (PETM). As geologic sources may have contributed over one third of global atmospheric methane in pre-industrial time, variability in methane flux from sedimentary

  17. Tectono-sedimentary architecture of Marie-Galante basin (Lesser Antilles fore arc)

    NASA Astrophysics Data System (ADS)

    Lebrun, Jean-Frédéric; Cornée, Jean-Jacques; Münch, Philippe; Guennoc, Pol

    2010-05-01

    Marie-Galante basin in the Lesser Antilles fore arc has experienced high amplitude (up to several thousand meters) vertical movements in response to both local tectonic in the fore-arc (trench perpendicular extensional tectonic) and geodynamical events at the plate interface, such as, long term interplate coupling changes, or ridges subduction or alternating period of under-platting/basal erosion... During the KaShallow cruises, we acquired ca. 3500km of high-resolution multichannel seismic reflection data (sparker and miniGI airgun sources), together with HR multibeam bathymetric (50m gridspacing DTM with ±2m depth precision) in the basin and over the shallow-water carbonate platforms surrounding the fore-arc islands. This geophysical dataset completes already existing seismic reflection data of lower resolution but deeper penetration. A systematic rock sampling using piston and rock corers and 2 ROV dives along remarkable cliffs, together with old dredge samples, provided petrological and sedimentary facies description, and datation (radiochronology and Micro/Nanno fossils) of the main stratigraphic series identified in seismic reflection through the basin. The basin divides into 3 sedimentary environments. We identify the architecture of the offshore carbonate platforms around the fore arc island and between them. Seismic profiles reveal the platforms prograding systems at their boundaries. This allows attempting a correlation between all the onshore/offshore archipelago platforms. Particularly, we evidence that the early Pleistocene upper series outcropping onshore extends offshore, and late Pleistocene/Holocene erosional surfaces are revealed. The "deep bassin", gently deepens southeastward from the volcanic arc islands of Basse-Terre and Dominica to the deep (5000m bsl) forearc basin at the accretionnary prism. Seismic profiles reveal the turbiditic infill of the basin. ROV dives permit to sample early Miocene pelagic sediments, and cores sample the late

  18. Applying Binary Forecasting Approaches to Induced Seismicity in the Western Canada Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Kahue, R.; Shcherbakov, R.

    2016-12-01

    The Western Canada Sedimentary Basin has been chosen as a focus due to an increase in the recent observed seismicity there which is most likely linked to anthropogenic activities related to unconventional oil and gas exploration. Seismicity caused by these types of activities is called induced seismicity. The occurrence of moderate to larger induced earthquakes in areas where critical infrastructure is present can be potentially problematic. Here we use a binary forecast method to analyze past seismicity and well production data in order to quantify future areas of increased seismicity. This method splits the given region into spatial cells. The binary forecast method used here has been suggested in the past to retroactively forecast large earthquakes occurring globally in areas called alarm cells. An alarm cell, or alert zone, is a bin in which there is a higher likelihood for earthquakes to occur based on previous data. The first method utilizes the cumulative Benioff strain, based on earthquakes that had occurred in each bin above a given magnitude over a time interval called the training period. The second method utilizes the cumulative well production data within each bin. Earthquakes that occurred within an alert zone in the retrospective forecast period contribute to the hit rate, while alert zones that did not have an earthquake occur within them in the forecast period contribute to the false alarm rate. In the resulting analysis the hit rate and false alarm rate are determined after optimizing and modifying the initial parameters using the receiver operating characteristic diagram. It is found that when modifying the cell size and threshold magnitude parameters within various training periods, hit and false alarm rates are obtained for specific regions in Western Canada using both recent seismicity and cumulative well production data. Certain areas are thus shown to be more prone to potential larger earthquakes based on both datasets. This has implications

  19. Evolutionary sequences and hydrocarbon potential of Kenya sedimentary basins

    SciTech Connect

    Cregg, A.K. )

    1991-03-01

    Kenya basins have evolved primarily through extension related to episodic continental rifting. In eastern Kenya, thick accumulations of sediments formed within grabens during the prerift phase (Precambrian to Carboniferous) of the Gondwana breakup. Synrift sedimentation (Late Carboniferous to Middle Jurassic) occurred within a north-south rift system, which included the Mandera basin, South Anza basin, and Lamu embayment. During the Early Jurassic, a marine transgression invaded the margins of the eastern Kenya rift basins, resulting in the deposition of platform carbonates and shales. A Callovian-aged salt basin formed in the offshore regions of the Lamu embayment. Intermittent tectonic activity and eustatic sea-level changes controlled sedimentation, which produced marine shales, carbonates or evaporites, and fluvio-deltaic to lacustrine sandstones. From the Early Cretaceous to recent, continental sediments were deposited within the North Anza and Turkana basins. These fluvial-lacustrine sediments are similar to the Lower Cretaceous sequences that have produced oil in the Mesozoic Sudanese Abu Gabra rift. Although exploration activities began in the early 1950s, significant occurrences of potential reservoir, source, and seal lithologies as well as trapping configurations remain in many areas. Favorable structures and sequences of reservoir sandstones and carbonates overlain by potentially sealing lacustrine or marine shales, evaporites, or volcanics have been noted. Potential source beds are believed to be present within shales of the lacustrine or marine depositional environments.

  20. Poly-phase Mesozoic-Cenozoic sedimentary basin evolution in the Altai region of western Mongolia

    NASA Astrophysics Data System (ADS)

    Howard, J. P.; Cunningham, W. D.; Davies, S. J.; Badarch, G.

    2003-04-01

    The Mongolian Altai is a major Cenozoic mountain range dominated by active transpressional deformation along a series of >100 km long NW-SE trending, dextral strike-slip fault systems. Deforming basins along the eastern flank of the Altai present a unique opportunity for studying the structural and stratigraphic evolution of intracontinental, intraplate, transpressional basins. This multi-disciplined study focuses on three distinct depocentres, the Dariv, Dzereg and Shargan basins, covering an area 300 km2. Field-based research documented the well-exposed Mesozoic and Cenozoic sedimentary fill, basin bounding faults, and faults and folds within the basins which have deformed the strata. The basin evolution, from Jurassic to present, is interpreted from these data. Mesozoic sediments are restricted to an elongate trough orientated NW-SE parallel to the modern range bounding structures and comprise axially derived fluvial sediments and lacustrine deposits which thin rapidly to the east. Several distinctive Mesozoic sedimentary units can be correlated between the three basins. Cenozoic deposits overlie a regional unconformity and comprise predominantly alluvial sediments with a distinct (though comparable) stratigraphy preserved in each of the present day basins. The distribution and deformation of the sedimentary succession records two distinct phases of basin evolution with different subsidence mechanisms. Thickness variations in the Mesozoic fill, combined with the presence of inverted faults and asymmetric folds, suggest that Mesozoic deposition occurred in an extensional half-graben. This hypothesis has important regional implications because it extends the zone of Mesozoic extension, already reported in southern and eastern Mongolia westwards into the Altai. The unconformity at the base of the Cenozoic succession represents a regional Paleogene peneplanation event. Cenozoic transpressional uplift of the Altai ranges divided the single elongate Mesozoic basin

  1. The tectonic and sedimentary structures of the Tyrrhenian rifted basin from multichannel seismic images

    NASA Astrophysics Data System (ADS)

    Vendrell, M. G.; Ranero, C. R.; Sallarès, V.; Prada, M.; Moeller, S.; Grevemeyer, I.; Zitellini, N.

    2012-04-01

    The Tyrrhenian basin has developed during the Neogene in a convergence setting between the Nubian and the European plates. The aim of this work is to unravel at basin-scale, the geological processes that have been working during the last 15 M.y. and giving the current structures. Data used in this study consist in a serie of multichannel seismic profiles acquired during the MEDOC survey with the Spanish R/V Sarmiento de Gamboa in 2010. These profiles have been processed to obtain images of the crustal structure. These seismic sections have been calibrated with data from some drillings from ODP (Oceanic Drilling Project) and DSDP (Deep Sea Drilling Project), for the identification of the main sedimentary units. In addition, this information has been integrated with full coverage multibeam bathymetry of the basin that permits to map the lateral extension of the main structures imaged in the seismic data. The seismic lines cross the entire basin at locations designed to provide images of the main tectonic units. The basin presents a strong lateral heterogeneity in the internal structure of the basement that may indicate lateral changes in its nature. The distribution of the sedimentary depositional centers, their size and thickness is also variable. We observe a transition from little extension in the northernmost region of the basin, to an increasing amount of extensions southeastwards, where extension has proceeded and may have lead to full crustal separation and mantle exhumation at the time of rifting. The conjugated margins show an asymmetric distribution of the extension and the relationships between faulting and sedimentary deposits. On the west side, the faults bound the largest sedimentary sub-basins in the Thyrrhenian, and conjugate side displays more dense faulting, but the faults have smaller offset, and lateral continuity implying smaller amounts of extensions. The sub-basins at this side are shallow and spatially restricted. The discontinuous nature of

  2. Detrital zircon (U-Th)/He thermochronometry in the sedimentary basin and its geological significance

    NASA Astrophysics Data System (ADS)

    Cai, C.; Qiu, N.

    2015-12-01

    The zircon (U-Th)/He thermochronometry has been used as a thermal indicator to study thermal history of the deep sedimentary basin at high temperature. The closure temperature and age of helium are important parameters for the zircon (U-Th)/He thermochronometry. In this paper, the zircon He closure temperature and its influence factors were studied by establishing the evolutionary pattern between zircon He ages and zircon burial depth based on examined zircon He ages of natural borehole samples obtained from the Cenozoic strara in the sedimentary basin. The results show that the zircon He closure temperature of natural samples in the sedimentary basin is approcimately 195℃, higher than the result (183℃) obtain from the thermal simulation experiments. The high He closure temperature resulted from long term radiation damage accumulation and high effective uranium. We also point out that grain radius, He corrected parameter, effective uranium concentration, radiation damage and radiogenic 4He concentration have apparent influence on the zircon He ages. This study is a revaluation of the conventional zircon He closure temperature. Thus, properly understanding the zircon He ages, closure temperature, and its influence factors, zircon (U-Th)/He dating can provide the true explanation of the testing zircon He ages, and has a great guiding significance in the studying of the evolution of source rocks and the process of hydrocarbon accumulation in the deep sedimentary basin.

  3. Resolving the Sedimentary Basin Structure from Oklahoma with Local Receiver Function

    NASA Astrophysics Data System (ADS)

    Zheng, D.; Ni, S.

    2015-12-01

    The teleseismic receiver function is defined as the radial component of P wave being deconvoluted from the vertical component of the earthquakes with magnitude larger than 5.5 at teleseismic distances. It has successfully been applied in resolving the structure of the crust and upper mantle in many regions. The receiver function can also be used to determine the thickness of sedimentary basin. However the corner frequency of the P waves from the teleseismic events (M>5.5) is relatively low and the high frequency content in the teleseismic P waves is attenuated, thus, the teleseismic receiver function is usually not sufficient to reveal details of sedimentary basin structure. Instead, local small earthquake (~ M3) generates P waves of short duration waveforms with high frequency content, which can be used to calculate receiver functions (called local receiver function). As a case study, we study waveform data from local earthquakes in Oklahoma. We first explore feasibility of local receiver function for different magnitude, focal depth, epicentral distance, filtering band and time window length. After local receiver functions are computed, we search the best velocity model to fit the local receiver function waveforms with the Differential Evolution (DE) algorithm which is a global optimization method. We invert the sedimentary basin structure in Oklahoma and find that this method is suitable for other area for the sedimentary basin structure where local seismic waveforms are available.

  4. Sedimentary geology of the middle Carboniferous of the Donbas region (Dniepr-Donets basin, Ukraine)

    PubMed Central

    van Hinsbergen, Douwe J. J.; Abels, Hemmo A.; Bosch, Wolter; Boekhout, Flora; Kitchka, Alexander; Hamers, Maartje; van der Meer, Douwe G.; Geluk, Mark; Stephenson, Randell A.

    2015-01-01

    The Paleozoic Dniepr-Donets Basin in Belarus, Ukraine, and Russia forms a major hydrocarbon province. Although well- and seismic data have established a 20 km thick stratigraphy, field-studies of its sediments are scarce. The inverted Donbas segment (Ukraine) exposes the middle Carboniferous part of the basin's stratigraphy. Here, we provide detailed sedimentological data from 13 sections that cover 1.5 of the total of 5 km of the Bashkirian and Moscovian stages and assess the paleoenvironment and paleo-current directions. Middle Carboniferous deposition occurred in a shelf environment, with coal deposition, subordinate fluvial facies, and abundant lower and middle shoreface facies, comprising an intercalated package of potential source and reservoir rocks. Sedimentary facies indicate a paleodepth range from below storm wave base to near-coastal swamp environments. Sedimentation and subsidence were hence in pace, with subtle facies changes likely representing relative sea-level changes. Paleocurrent directions are remarkably consistently southeastward in time and space in the different sedimentary facies across the Donbas Fold Belt, illustrating a dominant sedimentary infill along the basin axis, with little basin margin influence. This suggests that the middle Carboniferous stratigraphy of the Dniepr-Donets basin to the northwest probably contains significant amounts of fluvial sandstones, important for assessing hydrocarbon reservoir potential. PMID:25791400

  5. Sedimentary geology of the middle Carboniferous of the Donbas region (Dniepr-Donets basin, Ukraine)

    NASA Astrophysics Data System (ADS)

    van Hinsbergen, Douwe J. J.; Abels, Hemmo A.; Bosch, Wolter; Boekhout, Flora; Kitchka, Alexander; Hamers, Maartje; van der Meer, Douwe G.; Geluk, Mark; Stephenson, Randell A.

    2015-03-01

    The Paleozoic Dniepr-Donets Basin in Belarus, Ukraine, and Russia forms a major hydrocarbon province. Although well- and seismic data have established a 20 km thick stratigraphy, field-studies of its sediments are scarce. The inverted Donbas segment (Ukraine) exposes the middle Carboniferous part of the basin's stratigraphy. Here, we provide detailed sedimentological data from 13 sections that cover 1.5 of the total of 5 km of the Bashkirian and Moscovian stages and assess the paleoenvironment and paleo-current directions. Middle Carboniferous deposition occurred in a shelf environment, with coal deposition, subordinate fluvial facies, and abundant lower and middle shoreface facies, comprising an intercalated package of potential source and reservoir rocks. Sedimentary facies indicate a paleodepth range from below storm wave base to near-coastal swamp environments. Sedimentation and subsidence were hence in pace, with subtle facies changes likely representing relative sea-level changes. Paleocurrent directions are remarkably consistently southeastward in time and space in the different sedimentary facies across the Donbas Fold Belt, illustrating a dominant sedimentary infill along the basin axis, with little basin margin influence. This suggests that the middle Carboniferous stratigraphy of the Dniepr-Donets basin to the northwest probably contains significant amounts of fluvial sandstones, important for assessing hydrocarbon reservoir potential.

  6. Sedimentary geology of the middle Carboniferous of the Donbas region (Dniepr-Donets Basin, Ukraine).

    PubMed

    van Hinsbergen, Douwe J J; Abels, Hemmo A; Bosch, Wolter; Boekhout, Flora; Kitchka, Alexander; Hamers, Maartje; van der Meer, Douwe G; Geluk, Mark; Stephenson, Randell A

    2015-03-20

    The Paleozoic Dniepr-Donets Basin in Belarus, Ukraine, and Russia forms a major hydrocarbon province. Although well- and seismic data have established a 20 km thick stratigraphy, field-studies of its sediments are scarce. The inverted Donbas segment (Ukraine) exposes the middle Carboniferous part of the basin's stratigraphy. Here, we provide detailed sedimentological data from 13 sections that cover 1.5 of the total of 5 km of the Bashkirian and Moscovian stages and assess the paleoenvironment and paleo-current directions. Middle Carboniferous deposition occurred in a shelf environment, with coal deposition, subordinate fluvial facies, and abundant lower and middle shoreface facies, comprising an intercalated package of potential source and reservoir rocks. Sedimentary facies indicate a paleodepth range from below storm wave base to near-coastal swamp environments. Sedimentation and subsidence were hence in pace, with subtle facies changes likely representing relative sea-level changes. Paleocurrent directions are remarkably consistently southeastward in time and space in the different sedimentary facies across the Donbas Fold Belt, illustrating a dominant sedimentary infill along the basin axis, with little basin margin influence. This suggests that the middle Carboniferous stratigraphy of the Dniepr-Donets basin to the northwest probably contains significant amounts of fluvial sandstones, important for assessing hydrocarbon reservoir potential.

  7. Assessment of undiscovered conventional oil and gas resources of the Western Canada Sedimentary Basin, Canada, 2012

    USGS Publications Warehouse

    Higley, Debra

    2013-01-01

    The U.S. Geological Survey recently completed a geoscience-based assessment of undiscovered oil and gas resources of provinces within the Western Canada Sedimentary Basin. The Western Canada Sedimentary Basin primarily comprises the (1) Alberta Basin Province of Alberta, eastern British Columbia, and the southwestern Northwest Territories; (2) the Williston Basin Province of Saskatchewan, southeastern Alberta, and southern Manitoba; and (3) the Rocky Mountain Deformed Belt Province of western Alberta and eastern British Columbia. This report is part of the U.S. Geological Survey World Petroleum Resources Project assessment of priority geologic provinces of the world. The assessment was based on geoscience elements that define a total petroleum system (TPS) and associated assessment unit(s). These elements include petroleum source rocks (geochemical properties and petroleum generation, migration, and accumulation), reservoir description (reservoir presence, type, and quality), and petroleum traps (trap and seal types, and timing of trap and seal formation relative to petroleum migration). Using this framework, the Elk Point-Woodbend Composite TPS, Exshaw-Fernie-Mannville Composite TPS, and Middle through Upper Cretaceous Composite TPS were defined, and four conventional assessment units within the total petroleum systems were quantitatively assessed for undiscovered resources in the Western Canada Sedimentary Basin.

  8. Petroleum prospects for offshore sedimentary basins in the eastern Papua New Guinea and Solomon Islands regions

    SciTech Connect

    Bruns, T.R.; Vedder, J.G. )

    1990-06-01

    Intra-arc basins in the Buka-Bougainville region of Papua New Guinea and in the Solomon Islands contain thick sedimentary sequences that may be prospective for petroleum. The Queen Emma basin, between Bougainville and New Ireland, contains as much as 8 km of deformed Oligocene and younger strata. The Central Solomons Trough, which underlies New Georgia Sound, is a composite intra-arc basin that contains late Oligocene and younger strata as much as 7 km thick. Farther east, beneath Indispensable Strait, the down-faulted Indispensable basin locally contains as much as 5.4 km of Miocene( ) and younger strata, and the offshore part of Mbokokimbo basin off eastern Guadalcanal includes 6 km or more of late Miocene and younger strata. All of these basins have some of the attributes necessary to generate and trap petroleum. Structural and stratigraphic traps are common, including faulted anticlines, sedimentary wedges, and carbonate reefs and reef-derived deposits on submarine ridges and along the basin margins. The thickness of the basin deposits ensures that some strata are buried deeply enough to be within the thermal regime required for hydrocarbon generation. However, little source or reservoir rock information is available because of the lack of detailed surface and subsurface stratigraphy. Moreover, much of the basin sediment is likely to consist of volcaniclastic material, derived from uplifted volcanogenic rocks surrounding the basins, and may be poor in source and reservoir rocks. Until additional stratigraphic information is available, analysis of the petroleum potential of these basins is a matter of conjecture.

  9. Sedimentary basin geochemistry and fluid/rock interactions workshop

    SciTech Connect

    1991-12-31

    Fundamental research related to organic geochemistry, fluid-rock interactions, and the processes by which fluids migrate through basins has long been a part of the U.S. Department of Energy Geosciences program. Objectives of this program were to emphasize those principles and processes which would be applicable to a wide range of problems associated with petroleum discovery, occurrence and extraction, waste disposal of all kinds, and environmental management. To gain a better understanding of the progress being made in understanding basinal fluids, their geochemistry and movement, and related research, and to enhance communication and interaction between principal investigators and DOE and other Federal program managers interested in this topic, this workshop was organized by the School of Geology and Geophysics and held in Norman, Oklahoma in November, 1991.

  10. Geometry of the San Andreas Fault and Sedimentary Basin in the Northern Salton Trough

    NASA Astrophysics Data System (ADS)

    Fuis, G. S.; Bauer, K.; Catchings, R.; Goldman, M.; Ryberg, T.; Scheirer, D. S.; Langenheim, V. E.; Rymer, M. J.; Persaud, P.; Stock, J. M.; Hole, J. A.

    2014-12-01

    The Salton Seismic Imaging Project (SSIP) was undertaken, in part, to provide more accurate information on the plate-boundary faults and basin geometry in the Salton Trough region. One of these faults, the southernmost San Andreas Fault (SAF) zone in the northern Salton Trough (Coachella Valley), is considered by many to be likely to produce a large-magnitude earthquake in the near future. We report here on the geometry of the SAF and the adjacent sedimentary basin beneath the Coachella Valley. We interpret two seismic profiles in the northern Salton Trough that are orthogonal to the axis of the Coachella Valley. Seismic imaging, potential-field studies, and (or) earthquake hypocentral relocations along these profiles indicate that the active strand of the SAF dips NE. On a southern profile, through the Mecca Hills, we obtain a reflection image of the SAF zone in the depth range of 6-12 km that coincides with the microearthquake pattern reported by Hauksson et al. (2012), dipping ~ 60° NE. Steeply dipping reflectors above 6 km emerge at the surface at mapped secondary fault traces in the Mecca Hills, clearly defining a "flower structure" for the upper SAF. On the second profile, from Palm Springs to Landers, two alternative interpretations of SAF structure are possible. By one interpretation, which is based on earthquakes alone, the Banning and Garnet Hill Faults are two closely spaced faults, dipping ~ 60° NNE that pass through two aftershock clusters of the 1986 M 5.9 North Palm Springs earthquake. By the second interpretation, which is based on our reflection imaging on this line, the Banning and Garnet Hills faults converge at 10-km depth; below that depth, a single SAF dips ~ 60° NNE. In the second interpretation, the faults above 10 km resemble the flower structure interpreted beneath the Mecca Hills on our southern profile. The deeper fault in the second interpretation is subparallel to the closely spaced faults of the first interpretation but a few km

  11. A dynamical model of lithosphere extension and sedimentary basin formation

    NASA Technical Reports Server (NTRS)

    Houseman, G.; England, P.

    1986-01-01

    The effect of convection-induced stresses at the base of the continental lithosphere on surface and extensional deviatoric stresses is investigated. The biaxial strain in the continental lithosphere is controlled by power law creep in the upper and lower crust, brittle failure, and the Dorn plasticity law. The relationship between the lithosphere stress distribution and Moho temperatures is examined. The extension factors, basin subsidence, heat flow, and sediment loading of the lithosphere are studied.

  12. Sedimentary links between hillslopes and channels in a dryland basin

    NASA Astrophysics Data System (ADS)

    Hollings, R.

    2016-12-01

    The interface between hillslopes and channels is recognised as playing an important role in basin evolution and functioning. However, this interaction has not been described well in landscapes such as drylands, in which the diffuse process of runoff-driven sediment transport is important for sediment communication to the channel and to the basin outlet. This paper combines field measurements of surface sediment grain sizes in channels and on hillslopes with high resolution topography, >60 years of rainfall and runoff data from the Walnut Gulch Experimental Watershed (WGEW) in Arizona, and simple calculations of spatial stress distributions for various hydrologic scenarios to explore the potential for sediment to move from hillslopes to channels and through channels across the entire basin. Here we generalise the net movement of sediment in to or out of channel reaches, at high resolution in WGEW, as the balance between hillslope sediment supply to the channel and channel evacuation, in response to a variety of storms and discharge events. Our results show that downstream of small, unit source area watersheds, the balance in the channel often switches from being supply-dominated to being evacuation dominated for all scenarios. The low frequency but high discharge event in the channel seems to control the long term evolution of the channel, as stress is far greater for this scenario than other scenarios tested. The results draw on the high variability of rainfall characteristics to drive runoff events and so provides a physical explanation for long-term evolution of the channel network in drylands.

  13. Sedimentary environment of the La Rosa Formation, Maracaibo Basin

    SciTech Connect

    Rossi, D.; Noel, J.A.

    1993-02-01

    The La Rosa formation, Miocene consists of three facies: basal sand, the Santa Barbara, a middle shale, and the upper La Rosa Sand. The sands are variably productive. Paleontologic studies by others have shown the La Rosa Formation to be of marine origin. The shape of the SP curve of the Santa Barbara in bell shaped, caused by fining upward of the sand. This shape is typical with a beach deposit formed during transgression. The shale, because of its lithology and fossil content, represents shallow marine origin. The wine glass shape of the SP of the La Rosa sand is a beach sand, the result of a coarsening upward grain size during regression. An isopach of the La Rosa Formation and isoliths of the two sand units show a thickening trend from northeast to southwest. The thickest area trends diagonally across the center of the Basin. The study shows that the Miocene sea entered the basin from the northeast, transgressed southwesterly depositing the Santa Barbara sand on top of the unconformity as it went. The movement was constricted by the highlands on three sides of the basin. The shale was then deposited in the resulting shallow marine environment. As the highlands gradually rose, the sea regressed to the northeast depositing the La Rosa sand as it went.

  14. Earthquake ground motion prediction for real sedimentary basins: which numerical schemes are applicable?

    NASA Astrophysics Data System (ADS)

    Moczo, P.; Kristek, J.; Galis, M.; Pazak, P.

    2009-12-01

    Numerical prediction of earthquake ground motion in sedimentary basins and valleys often has to account for P-wave to S-wave speed ratios (Vp/Vs) as large as 5 and even larger, mainly in sediments below groundwater level. The ratio can attain values larger than 10 in unconsolidated sediments (e.g. in Ciudad de México). In a process of developing 3D optimally-accurate finite-difference schemes we encountered a serious problem with accuracy in media with large Vp/Vs ratio. This led us to investigate the very fundamental reasons for the inaccuracy. In order to identify the very basic inherent aspects of the numerical schemes responsible for their behavior with varying Vp/Vs ratio, we restricted to the most basic 2nd-order 2D numerical schemes on a uniform grid in a homogeneous medium. Although basic in the specified sense, the schemes comprise the decisive features for accuracy of wide class of numerical schemes. We investigated 6 numerical schemes: finite-difference_displacement_conventional grid (FD_D_CG) finite-element_Lobatto integration (FE_L) finite-element_Gauss integration (FE_G) finite-difference_displacement-stress_partly-staggered grid (FD_DS_PSG) finite-difference_displacement-stress_staggered grid (FD_DS_SG) finite-difference_velocity-stress_staggered grid (FD_VS_SG) We defined and calculated local errors of the schemes in amplitude and polarization. Because different schemes use different time steps, they need different numbers of time levels to calculate solution for a desired time window. Therefore, we normalized errors for a unit time. The normalization allowed for a direct comparison of errors of different schemes. Extensive numerical calculations for wide ranges of values of the Vp/Vs ratio, spatial sampling ratio, stability ratio, and entire range of directions of propagation with respect to the spatial grid led to interesting and surprising findings. Accuracy of FD_D_CG, FE_L and FE_G strongly depends on Vp/Vs ratio. The schemes are not

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  16. Cryogenic formation of brine and sedimentary mirabilite in submergent coastal lake basins, Canadian Arctic

    NASA Astrophysics Data System (ADS)

    Grasby, Stephen E.; Rod Smith, I.; Bell, Trevor; Forbes, Donald L.

    2013-06-01

    Two informally named basins (Mirabilite Basins 1 and 2) along a submergent coastline on Banks Island, Canadian Arctic Archipelago, host up to 1 m-thick accumulations of mirabilite (Na2SO4·10H2O) underlying stratified water bodies with basal anoxic brines. Unlike isostatically uplifting coastlines that trap seawater in coastal basins, these basins formed from freshwater lakes that were transgressed by seawater. The depth of the sill that separates the basins from the sea is shallow (1.15 m), such that seasonal sea ice formation down to 1.6 m isolates the basins from open water exchange through the winter. Freezing of seawater excludes salts, generating dense brines that sink to the basin bottom. Progressive freezing increases salinity of residual brines to the point of mirabilite saturation, and as a result sedimentary deposits of mirabilite accumulate on the basin floors. Brine formation also leads to density stratification and bottom water anoxia. We propose a model whereby summer melt of the ice cover forms a temporary freshwater lens, and rather than mixing with the underlying brines, it is exchanged with seawater once the ice plug that separates the basins from the open sea melts. This permits progressive brine development and density stratification within the basins.

  17. Processing of thermal parameters for the assessment of geothermal potential of sedimentary basins

    NASA Astrophysics Data System (ADS)

    Pasquale, V.; Chiozzi, P.; Gola, G.; Verdoya, M.

    2009-04-01

    The growing interest on renewable energy sources is stimulating new efforts aimed at the assessment of geothermal potential in several countries, and new developments are expected in the near future. In this framework, a basic step forward is to focus geothermal investigations on geological environments which so far have been relatively neglected. Some intracontinental sedimentary basins could reveal important low enthalpy resources. The evaluation of the geothermal potential in such geological contexts involves the synergic use of geophysical and hydrogeological methodologies. In sedimentary basins a large amount of thermal and hydraulic data is generally available from petroleum wells. Unfortunately, borehole temperature data are often affected by a number of perturbations which make very difficult determination of the true geothermal gradient. In this paper we addressed the importance of the acquisition of thermal parameters (temperature, geothermal gradient, thermal properties of the rock) and the technical processing which is necessary to obtain reliable geothermal characterizations. In particular, techniques for corrections of bottom-hole temperature (BHT) data were reviewed. The objective was to create a working formula usable for computing the undisturbed formation temperature for specific sedimentary basins. As test areas, we analysed the sedimentary basins of northern Italy. Two classical techniques for processing temperature data from oil wells are customarily used: (i) the method by Horner, that requires two or more measurements of bottom-hole temperatures carried out at the same depth but at different shut-in times te and (ii) the technique by Cooper and Jones, in which several physical parameters of the mud and formation need to be known. We applied both methods to data from a number of petroleum explorative wells located in two areas of the Po Plain (Apenninic buried arc and South Piedmont Basin - Pedealpine homocline). From a set of about 40 wells

  18. Nature and tectonic implications of uneven sedimentary filling of the South China Sea oceanic basin

    NASA Astrophysics Data System (ADS)

    Yin, Shaoru; Li, Jiabiao; Ding, Weiwei; Fang, Yinxia

    2017-04-01

    The IODP Expedition 349 in 2014, for the first time, illustrated significant differences of sediment rate and lithology in the central South China Sea (SCS) oceanic basin. Based on seismic reflection profiles tied to IODP349 drilling data, we investigated characteristics of sedimentary filling of the whole SCS oceanic basin, and examined their implications for tectonics. Results show that sediments fill the SCS oceanic basin mainly in three depositional patterns. Firstly, during the Oligocene to middle Miocene, sediments amassed almost solely and then connected like a band parallel to the continent in a low average sediment rate (<10 m/Myr) in the northern oceanic basin. These sediments were deposited mainly in the form of submarine fans and mass transport deposits. Sediments were predominately supplied by the Red and Pearl Rivers and the Dongsha Islands. The sedimentary characteristics likely reflect the latest early Miocene end of seafloor spreading of the SCS and the first-phase rapid uplift of the Tibetan Plateau. Secondly, during the late Miocene, deposition mainly occurred in the Northwest Sub-basin and extended southeastward with a middle average sediment rate ( 30 m/Myr). Sediments were mostly transported by the Red River and Xisha Trough and deposited in the form of submarine fans. The abnormal increase of sediment rate in the Northwest Sub-basin reflects late Miocene slip reversal of the Red River Fault. Finally, since the Pliocene, sediments gradually propagated northeastward in the Southwestern Sub-basin, and accumulated rapidly in the southeastern and northeastern basin, especially in the northern Manila Trench during the Quaternary, in an average sediment rate about 60-80 m/Myr. These sediments were transported mainly by submarine canyons and settled in the form of submarine fans and canyon-overbank deposition. Sediments came from four major sources, including Taiwan, Dongsha Islands, Mekong River, and northern Palawan. The Pliocene to Quaternary

  19. An object-oriented expert system for sedimentary basin analysis with applications in petroleum geology

    SciTech Connect

    Miller, B.M. )

    1990-05-01

    Most of the world's energy resources and many of its metallic and mineral resources are derived from complex sources in sedimentary basins. A comprehensive basin analysis requires an understanding of data from many specialties, including sedimentology, stratigraphy geophysics, structural geology, and geochemistry. Such an integrated analysis is almost impossible without a computer. Research efforts in the US Geological Survey are currently being directed at exploring the feasibility of applying expert systems and knowledge acquisition techniques to the design and development of a global system of classification and geological analysis of sedimentary basins to assess their petroleum potential. The primary objective is the design of a prototype object-oriented expert system interfaced with a geographic information system (GIS) that captures both the logic used to define the geologic concepts and the reasoning under uncertainty that enables geologists to understand and reconstruct the geologic history of a sedimentary basin. NEXPERT OBJECT, a hybrid expert system that has the ability to support both a reasoning system and an object-oriented representation, is currently being used as the design tool to provide high-level, expert-oriented features to create, edit, and build knowledge bases for the basin analysis program. This system provides these capabilities through documentation of major basin analysis components such as stratigraphy, structural geology, and sedimentology. It is designed to analyze the traditional concepts of source, reservoir, and trapping mechanism; to help in the diagnosis of geological conditions favorable for the occurrence of petroleum or other energy resources; and to assist in the assessment of these resources. The design and content of the expert system program is discussed for application to basin analysis studies.

  20. Sedimentary response to subsidence history of Illinois basin

    SciTech Connect

    Heidlauf, D.T.; Hsui, A.T.; Klein de V., G.

    1986-05-01

    The Illinois basin formed through initial isostatic subsidence and subsequent thermal subsidence in response to mantle intrusion that formed a three-arm rift 535-555 Ma. Tectonic subsidence curves calculated from three wells show that, when extended across the Sauk-Tippecanoe, Ordovician-Silurian, and Tippecanoe-Kaskaskia unconformities, they fit a post-rift thermal contraction model. These unconformities formed because, as suggested by some investigators for other areas, the rate of eustatic sea level fall exceeded the rate of thermal basement subsidence. Residual tectonic subsidence curves were calculated by subtracting post-rift thermal contraction curves from calculated tectonic subsidence curves. These residual curves indicate misassigned depositional times, periods of non-equilibrium sedimentation and subsidence, and the start of new subsidence episodes. Middle to Late Ordovician negative residual curves were corrected to null values by revising depositional times. Accordingly, the duration of the Blackriveran expands to 17 m.y., and the Trentonian through middle Maysvillian contracts to 2.5 m.y. Silurian and Late Devonian through Early Mississippian positive residual curves correspond to formation and filling of 300-m-deep, sediment-starved basins. A strong negative residual curve, beginning in the middle Mississippian, corresponds to a second tectonic subsidence event.

  1. Sedimentary record from the Canada Basin, Arctic Ocean: implications for late to middle Pleistocene glacial history

    NASA Astrophysics Data System (ADS)

    Dong, Linsen; Liu, Yanguang; Shi, Xuefa; Polyak, Leonid; Huang, Yuanhui; Fang, Xisheng; Liu, Jianxing; Zou, Jianjun; Wang, Kunshan; Sun, Fuqiang; Wang, Xuchen

    2017-05-01

    Sediment core ARC4-BN05 collected from the Canada Basin, Arctic Ocean, covers the late to middle Quaternary (Marine Isotope Stage - MIS - 1-15, ca. 0.5-0.6 Ma) as estimated by correlation to earlier proposed Arctic Ocean stratigraphies and AMS14C dating of the youngest sediments. Detailed examination of clay and bulk mineralogy along with grain size, content of Ca and Mn, and planktic foraminiferal numbers in core ARC4-BN05 provides important new information about sedimentary environments and provenance. We use increased contents of coarse debris as an indicator of glacier collapse events at the margins of the western Arctic Ocean, and identify the provenance of these events from mineralogical composition. Notably, peaks of dolomite debris, including large dropstones, track the Laurentide Ice Sheet (LIS) discharge events to the Arctic Ocean. Major LIS inputs occurred during the stratigraphic intervals estimated as MIS 3, intra-MIS 5 and 7 events, MIS 8, and MIS 10. Inputs from the East Siberian Ice Sheet (ESIS) are inferred from peaks of smectite, kaolinite, and chlorite associated with coarse sediment. Major ESIS sedimentary events occurred in the intervals estimated as MIS 4, MIS 6 and MIS 12. Differences in LIS vs. ESIS inputs can be explained by ice-sheet configurations at different sea levels, sediment delivery mechanisms (iceberg rafting, suspension plumes, and debris flows), and surface circulation. A long-term change in the pattern of sediment inputs, with an apparent step change near the estimated MIS 7-8 boundary (ca. 0.25 Ma), presumably indicates an overall glacial expansion at the western Arctic margins, especially in North America.

  2. Carbon and Nitrogen Stable Isotopes of Sedimentary Organic Matter From the Santa Monica Basin

    NASA Astrophysics Data System (ADS)

    Luo, J. Y.; Erohina, T.; Paytan, A.

    2005-12-01

    The California Continental Borderland is a tectonically active area, characterized by 23 basins located at different distances from sources of terrigenous sediment, local intermittent rivers and coastal upwelling zones and thus displaying different sedimentation sources and processes. The Santa Monica Basin (938m depth), a Southern California Inner Borderland basin, is a closed basin and fed by the Santa Barbara littoral cell. During sea level lowstands, the littoral cell is inactive and the canyon was fed directly by the Santa Clara River, which is presently not dammed and is known to be capable of generating hyperpycnal flows during ENSO related floods. Ocean Drilling Program (ODP) Site 1015 was drilled in the basin plain area and penetrated through a 150-meter late Quaternary sedimentary section. The sediments recovered at Site 1015 are grouped into a single lithostratigraphic unit consisting of three alternating sedimentary units: medium- to fine-grained sand, silty clay, and nanofossil clay. Samples of the drill core from the top 60 meters of sediment was obtained and analyzed at ~50cm intervals to obtain a high-resolution record of organic matter distribution and isotope record within the different intervals. The δ13C values of total organic carbon (TOC) and δ15N values, as well as the C/N ratio were obtained and used to differentiate between marine and terrestrial sediment inputs to the basin. Additionally, the TOC data may indicate if highstand and lowstand deposits show significant compositional differences.

  3. Tectonic control of the sedimentary record: Constraints from quantitative basin modeling

    SciTech Connect

    Cloetingh, S.A.P.L.; Van Balen, R.T.; Zoetemeijer, B.P. )

    1993-09-01

    The incorporation of finite strength of the lithosphere during rifting in models for extensional basin formation in conjunction with temporal changes in tectonic stress levels leads to the prediction of rapid vertical motions in these basins with a rate and magnitude comparable to second- and third-order changes in relative sea level. We present results of modeling simulations, incorporating the interplay of flank uplift and erosion for rifted basins in the northern Atlantic/North Sea area. The incorporation of the mechanical properties of the lithosphere in forward stratigraphic modeling appears also to be of key importance for an accurate prediction of the record of vertical motions in foreland fold and thrust belts. Models invoking the mechanical coupling between plate flexure and near-surface brittle tectonics are capable of producing onlap/offlap patterns in syntectonic basins sometimes strikingly similar to the basin-fill signatures attributed to third-order glacio-eustatic signals. The full incorporation of structural geological constraints in forward modeling of basin stratigraphy proves to be a powerful instrument in linking different temporal and spatial scales in the sedimentary record. This approach also leads to a quantification of the tectonic control of the sedimentary record in frequency bands hitherto primarily attributed to external forcing functions.

  4. Extensional Tectonics and Sedimentary Architecture Using 3-D Seismic Data: An Example from Hydrocarbon-Bearing Mumbai Offshore Basin, West Coast of India

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, D. K.; Bhowmick, P. K.; Mishra, P.

    2016-12-01

    In offshore sedimentary basins, analysis of 3-D seismic data tied with well log data can be used to deduce robust isopach and structure contour maps of different stratigraphic formations. The isopach maps give depocenters whereas structure contour maps give structural relief at a specific time. Combination of these two types of data helps us decipher horst-graben structures, sedimentary basin architecture and tectono-stratigraphic relations through Tertiary time. Restoration of structural cross sections with back-stripping of successively older stratigraphic layers leads to better understand tectono-sedimentary evolution of a basin. The Mumbai (or Bombay) Offshore Basin is the largest basin off the west coast of India and includes Bombay High giant oil/gas field. Although this field was discovered in 1974 and still producing, the basin architecture vis-à-vis structural evolution are not well documented. We take the approach briefly outlined above to study in detail three large hydrocarbon-bearing structures located within the offshore basin. The Cretaceous Deccan basalt forms the basement and hosts prodigal thickness (> 8 km at some localities) of Tertiary sedimentary formations.A two stage deformation is envisaged. At the first stage horst and graben structures formed due to approximately E-W extensional tectonics. This is most spectacularly seen at the basement top level. The faults associated with this extension strike NNW. At the second stage of deformation a set of ENE-striking cross faults have developed leading to the formation of transpressional structures at places. High rate of early sedimentation obliterated horst-graben architecture to large extent. An interesting aspect emerges is that the all the large-scale structures have rather low structural relief. However, the areal extent of such structures are very large. Consequently, these structures hold commercial quantities of oil/gas.

  5. Stress Map 2.0: Updating the Stress Map of the Western Canadian Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Mallyon, D.; Schmitt, D. R.; Currie, C. A.; Gu, Y. J.; Heidbach, O.

    2015-12-01

    The greatest horizontal compression in much of the Western Canada Sedimentary Basin appears to uniformly trend NE-SW. Beyond this, major gaps remain in our knowledge of stress magnitudes and even faulting regimes. This lack of quantitative information impedes a proper understanding of seismic events that appear to be linked to hydraulic fracturing stimulations. Apart from this immediate concern, such seismicity could impact long term green-house gas sequestration and geothermal energy development. As part of the Helmholtz-Alberta geothermal collaboration, we are developing a program to update this crustal stress state information. The program consists of more immediate studies related to conventional analysis of borehole image logs, core fractures, and transient pressure records as can be made available. Data sets analyzed to date include logs to 3.5 km depth from areas experiencing induced seismicity, from 2.5 km depth within the Precambrian craton in NE Alberta, and to 400 m depth within a large carbonate platform. All these data largely confirm the NE-SW stress directions. In some cases, the configurations of drilling induced tensile fractures and borehole breakouts allow the faulting regime to be constrained. The addition of new seismometers to the region is also allowing for the refinement of earthquake focal mechanisms. Finally, a dramatic contrast in lithosphere thickness, composition and geothermal gradient exists at the contact between the Cordillera and the North American craton; therefore, lithosphere-scale numerical models are also being developed to quantify the relative contribution of geodynamic processes, such as mantle flow and contact geometry, to the observed stress regime within the basin.

  6. Geomechanical modeling of salt-sediment interaction in evolving sedimentary basins

    NASA Astrophysics Data System (ADS)

    Flemings, P. B.; Luo, G.; Nikolinakou, M. A.; Hudec, M.

    2011-12-01

    We use coupled geomechanical modeling to describe how stress and pore pressure evolve in sedimentary basins where salt is present. We treat salt as a visco-elastic material and sediment as a poro-elastic, poro-elastoplastic or Coloumb plastic material. At geological timescales (100 k.y. and longer) salt flow releases differential stresses, whereas sediment maintains significant differential stresses. Significant perturbations in stress and pore pressure occur near salt bodies to accommodate these material behaviors. In low permeability systems, where salt is encased by sediment, the least principal stress and pore pressure are reduced at the crest and base of salt whereas they are elevated at the flanks of salt. Salt loading induces pore pressures that extend kilometers away from the salt. These results are similar to drilling results that record reduced pore pressure and reduced least principal stress beneath salt. We also consider the case where a salt sheet advances across sediment. When salt advances over low permeability sediment, pore pressures rise and effective stresses are low beneath the salt, and the salt sheet advances rapidly. In contrast, when salt advances over a high permeability substrate, fluids drain, pore pressures are low and effective stresses are high beneath salt, and the salt sheet advances slowly. The magnitude of the overpressure beneath the salt can be estimated from its geometry. Our approach extends beyond large-scale uncoupled basin models that have assumed only uniaxial (vertical) strain. This coupled approach provides insight as to the interpretation of large scale geological structures and has the potential to predict in situ stresses and pore pressures.

  7. Report of the Workshop on Geologic Applications of Remote Sensing to the Study of Sedimentary Basins

    SciTech Connect

    Lang, H.R.

    1985-08-01

    The Workshop on Geologic Applications of Remote Sensing to the Study of Sedimentary Basins, held January 10 to 11, 1985 in Lakewood, Colorado, involved 43 geologists from industry, government, and academia. Disciplines represented ranged from vertebrate paleontology to geophysical modeling of continents. Deliberations focused on geologic problems related to the formation, stratigraphy, structure, and evolution of foreland basins in general, and to the Wind River/Bighorn Basin area of Wyoming in particular. Geological problems in the Wind River/Bighorn basin area that should be studied using state-of-the-art remote sensing methods were identified. These include: (1) establishing the stratigraphic sequence and mapping, correlating, and analyzing lithofacies of basin-filling strata in order to refine the chronology of basin sedimentation, and (2) mapping volcanic units, fracture patterns in basement rocks, and Tertiary-Holocene landforms in searches for surface manifestations of concealed structures in order to refine models of basin tectonics. Conventional geologic, topographic, geophysical, and borehole data should be utilized in these studies. Remote sensing methods developed in the Wind River/Bighorn Basin area should be applied in other basins.

  8. Report of the Workshop on Geologic Applications of Remote Sensing to the Study of Sedimentary Basins

    NASA Technical Reports Server (NTRS)

    Lang, H. R. (Editor)

    1985-01-01

    The Workshop on Geologic Applications of Remote Sensing to the Study of Sedimentary Basins, held January 10 to 11, 1985 in Lakewood, Colorado, involved 43 geologists from industry, government, and academia. Disciplines represented ranged from vertebrate paleontology to geophysical modeling of continents. Deliberations focused on geologic problems related to the formation, stratigraphy, structure, and evolution of foreland basins in general, and to the Wind River/Bighorn Basin area of Wyoming in particular. Geological problems in the Wind River/Bighorn basin area that should be studied using state-of-the-art remote sensing methods were identified. These include: (1) establishing the stratigraphic sequence and mapping, correlating, and analyzing lithofacies of basin-filling strata in order to refine the chronology of basin sedimentation, and (2) mapping volcanic units, fracture patterns in basement rocks, and Tertiary-Holocene landforms in searches for surface manifestations of concealed structures in order to refine models of basin tectonics. Conventional geologic, topographic, geophysical, and borehole data should be utilized in these studies. Remote sensing methods developed in the Wind River/Bighorn Basin area should be applied in other basins.

  9. Modern sedimentary environments in a large tidal estuary, Delaware Bay

    USGS Publications Warehouse

    Knebel, H. J.

    1989-01-01

    Data from an extensive grid of sidescan-sonar records reveal the distribution of sedimentary environments in the large, tidally dominated Delaware Bay estuary. Bathymetric features of the estuary include large tidal channels under the relatively deep (> 10 m water depth) central part of the bay, linear sand shoals (2-8 m relief) that parallel the sides of the tidal channels, and broad, low-relief plains that form the shallow bay margins. The two sedimentary environments that were identified are characterized by either (1) bedload transport and/or erosion or (2) sediment reworking and/or deposition. Sand waves and sand ribbons, composed of medium to coarse sands, define sites of active bedload transport within the tidal channels and in gaps between the linear shoals. The sand waves have spacings that vary from 1 to 70 m, amplitudes of 2 m or less, and crestlines that are usually straight. The orientations of the sand waves and ribbons indicate that bottom sediment movement may be toward either the northwest or southeast along the trends of the tidal channels, although sand-wave asymmetry indicates that the net bottom transport is directed northwestward toward the head of the bay. Gravelly, coarse-grained sediments, which appear as strongly reflective patterns on the sonographs, are also present along the axes and flanks of the tidal channels. These coarse sediments are lag deposits that have developed primarily where older strata were eroded at the bay floor. Conversely, fine sands that compose the linear shoals and muddy sands that cover the shallow bay margins appear mainly on the sonographs either as smooth featureless beds that have uniform light to moderate shading or as mosaics of light and dark patches produced by variations in grain size. These acoustic and textural characteristics are the result of sediment deposition and reworking. Data from this study (1) support the hypothesis that bed configurations under deep tidal flows are functions of current

  10. Palynostratigraphy of the Erkovtsy field of brown coal (the Zeya-Bureya sedimentary basin)

    SciTech Connect

    Kezina, T.V.; Litvinenko, N.D.

    2007-08-15

    The Erkovtsy brown coal field in the northwestern Zeya-Bureya sedimentary basin (129-130{sup o}E, 46-47{sup o}N) is structurally confined to southern flank of the Mesozoic-Cenozoic Belogor'e depression. The verified stratigraphic scheme of the coalfield sedimentary sequence is substantiated by palynological data on core samples from 18 boreholes sampled in the course of detailed prospecting and by paleobotanical analysis of sections in the Yuzhnyi sector of the coalfield (data of 1998 by M.A. Akhmetiev and S.P. Manchester). Sections of the Erkovtsy, Arkhara-Boguchan, and Raichikha brown-coal mines are correlated. Stratigraphic subdivisions distinguished in the studied sedimentary succession are the middle and upper Tsagayan subformations (the latter incorporating the Kivda Beds), Raichikha, Mukhino, Buzuli, and Sazanka formations.

  11. Sedimentary and structural controls on seismogenic slumping within mass transport deposits from the Dead Sea Basin

    NASA Astrophysics Data System (ADS)

    Alsop, G. I.; Marco, S.; Weinberger, R.; Levi, T.

    2016-10-01

    Comparatively little work has been undertaken on how sedimentary environments and facies changes can influence detailed structural development in slump sheets associated with mass transport deposits (MTDs). The nature of downslope deformation at the leading edge of MTDs is currently debated in terms of frontally emergent, frontally confined and open-toed models. An opportunity to study and address these issues occurs within the Dead Sea Basin, where six individual slump sheets (S1-S6) form MTDs in the Late Pleistocene Lisan Formation. All six slumps, which are separated from one another by undeformed beds, are traced towards the NE for up to 1 km, and each shows a change in sedimentary facies from detrital-rich in the SW, to more aragonite-rich in the NE. The detrital-rich facies is sourced predominantly from the rift margin 1.5 km further SW, while the aragonite-rich facies represents evaporitic precipitation in the hyper saline Lake Lisan. The stacked system of MTDs translates downslope towards the NE and follows a pre-determined sequence controlled by the sedimentary facies. Each individual slump roots downwards into underlying detrital-rich layers and displays a greater detrital content towards the SW, which is marked by increasing folding, while increasing aragonite content towards the NE is associated with more discrete thrusts. The MTDs thin downslope towards the NE, until they pass laterally into undeformed beds at the toe. The amount of contraction also reduces downslope from a maximum of 50% to < 10% at the toe, where upright folds form diffuse 'open-toed' systems. We suggest that MTDs are triggered by seismic events, facilitated by detrital-rich horizons, and controlled by palaeoslope orientation. The frequency of individual failures is partially controlled by local environmental influences linked to detrital input and should therefore be used with some caution in more general palaeoseismic studies. We demonstrate that MTDs display 'open toes' where

  12. Deep seismic reflection profiling of sedimentary basins offshore Brazil: Geological objectives and preliminary results in the Sergipe Basin

    NASA Astrophysics Data System (ADS)

    Mohriak, Webster Ueipass; Lira Rabelo, JoséHenrique; De Matos, Renato Darros; De Barros, Mozart C.

    1995-12-01

    The first deep seismic reflection profiles offshore Brazil were acquired in Campos Basin and processed to 10 s TWT in 1984. Starting in 1989, Petrobrás acquired an extensive data set of deep seismic profiles using special acquisition equipment capable of effectively penetrating through the sedimentary layers and imaging the whole crustal architecture. These deep (18 s TWT) seismic reflection profiles extend across the Atlantic-type marginal basins, from the platform to the deepwater province, presently considered frontier regions for petroleum exploration. This work addresses the geological objectives of a deep seismic profile in the Sergipe Basin and discusses the results obtained by integrating regional seismic, gravity and magnetic data. When combined, these data provide evidence that deep seismic reflectors observed in the Sergipe Basin are related to intracrustal-upper mantle structures rather than sedimentary features. The deep seismic reflection profile in the Sergipe Basin also suggests that, rather than a non-volcanic passive margin, the deepwater extension of this basin is marked by several magmatic structures, including thick wedges of seaward-dipping reflectors and volcanic plugs. These magmatic features are associated with basinforming processes resulting from lithospheric extension during the breakup of Gondwana in the Early Cretaceous and subsequent emplacement of oceanic crust. These results are compared to the crustal scale structures observed in the Campos Basin, in the southeastern margin of Brazil. The interpretation of the deep structure of these basins indicates that final separation between the South American and African plates formed passive margins characterized by different patterns of crustal attenuation underlying the rift blocks.

  13. Estimation of Potential Carbon Dioxide Storage Capacities of Onshore Sedimentary Basins in Republic of Korea

    NASA Astrophysics Data System (ADS)

    Park, S.; Kim, J.; Lee, Y.

    2010-12-01

    The potential carbon dioxide storage capacities of the five main onshore sedimentary basins (Chungnam, Gyeongsang, Honam, Mungyeong, and Taebaeksan Basins) in Republic of Korea are estimated based on the methods suggested by the United States National Energy Technology Laboratory (NETL). The target geologic formations considered for geologic storage of carbon dioxide in the sedimentary basins are sandstone and coal beds. The density of carbon dioxide is set equal to 446.4 kg/m3. The adsorption capacity and density of coal (anthracite) are set equal to 2.71 × 10-2 kg/kg and 1.82 × 103 kg/m3, respectively. The average storage efficiency factors for sandstone and coal are set equal to 2.5% and 34.0%, respectively. The Chungnam Basin has the sandstone volume of 72 km3 and the coal volume of 1.24 km3. The average porosity of sandstone in the Chungnam Basin is 3.8%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Chungnam Basin are estimated to be 31 Mton and 21 Mton, respectively. The Gyeongsang Basin has the sandstone volume of 1,960 km3. The average porosity of sandstone in the Gyeongsang Basin is 4.6%. As a result, the potential carbon dioxide storage capacity of sandstone in the Gyeongsang Basin is estimated to be 1,011 Mton. The Honam Basin has the sandstone volume of 8 km3 and the coal volume of 0.27 km3. The average porosity of sandstone in the Honam Basin is 1.9%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Honam Basin are estimated to be 2 Mton and 5 Mton, respectively. The Mungyeong Basin has the sandstone volume of 60 km3 and the coal volume of 0.66 km3. The average porosity of sandstone in the Mungyeong Basin is 2.0%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Mungyeong Basin are estimated to be 13 Mton and 11 Mton, respectively. The Taebaeksan Basin has the sandstone volume of 71 km3 and the coal volume of 0.73 km3. The

  14. Short and long term sediment flux in an inner-alpine sedimentary basin (Hohe Tauern, Austria)

    NASA Astrophysics Data System (ADS)

    Götz, Joachim; Schrott, Lothar

    2015-04-01

    Combined analyses of short and long term sediment fluxes in mountain environments have been rarely carried out until now. However, the relation of integrated postglacial landform volumes to single events (e.g. debris flows) provide the opportunity to establish meaningful frequency-magnitude-relationships, to evaluate present day geomorphic activity more reasonable, and to complement time series data typically covering only a short period of time. In this study we investigate recent and postglacial sediment flux in a small-scale denudation-accumulation system in the Hohe Tauern Range (Austrian Alps) using a complementary multi method approach including surface, subsurface and temporal analyses. We reconstructed the infill history and sedimentary architecture of the almost closed Gradenmoos basin, which has been filled up with sediments from different source areas delivered by mainly debris flows, rockfall and avalanche activity, and fluvial processes. In former times, glacial, glacio-fluvial and lacustrine sedimentation contributed to the basin fill as well. This process diversity led to a variety of interfingering and nested sediment storage landforms with a complex postglacial stratigraphy. Most important landforms include floodplain and peat bog deposits in the basin center as well as debris cones and talus sheets adjacent to the surrounding rockwalls. Postglacial basin sedimentation started after Younger Dryas deglaciation as indicated by radiocarbon ages of early-Holocene sediment core samples taken in the basin. For the following 7500 years, trap efficiency was maximised due to the presence of a former lake which is proved by morphometric, palynologic and stratigraphic data. Peat bog development finally began around 3500 years ago in the distal part of the basin. We interpolated the bedrock interface below the basin fill deposits using bedrock coordinates derived from core-drilling, geophysical prospection (electrical resistivity tomography, refraction seismic

  15. Sedimentary Basins: A Deeper Look at Seattle and Portland's Earthquake Hazards

    NASA Astrophysics Data System (ADS)

    Thompson, M.; Frankel, A. D.; Wirth, E. A.; Vidale, J. E.; Han, J.

    2015-12-01

    Seattle, Washington and Portland, Oregon, two major metropolitan areas in the Pacific Northwest, are vulnerable to earthquakes on active local faults, deep intraslab earthquakes, and megathrust earthquakes on the Cascadia Subduction Zone (CSZ). Both cities are located within sedimentary basins that could increase this hazard. The Seattle basin is ~8 km in depth and is located beneath downtown Seattle. The 6-km-deep Tualatin basin (McPhee et al., 2014) sits below and west of downtown Portland with the shallow Portland basin to the northeast. Unlike other West Coast sedimentary basins, the Tualatin contains a higher-velocity Columbia River basalt layer between sediment layers. The velocity contrast between stiff bedrock surrounding the basins and soft sediment within can cause seismic waves to amplify greatly, increasing shaking intensity and duration at the surface. For example, our observations show amplification of seismic waves by factors of 2 - 4 within the Seattle basin. Basin geometry can also increase local shaking by converting incident S-waves to surface waves, and focusing S-waves at basin edges. We characterize effects of the Seattle, Tualatin and Portland basins by modeling with 3-D numerical methods. To evaluate these effects, we use data from the 2001 M6.8 Nisqually, the 2009 M4.5 Kingston, and the 2006 M3.8 Vancouver earthquakes recorded by stations operated by the US Geological Survey (10 - 25 stations) and the Pacific Northwest Seismic Network (7 - 81 stations). Time differences between S-waves and S-converted-to-P-waves at basin/bedrock interfaces as well as reverberations from teleseisms (global earthquakes) are used to constrain the basin depth and structure of the three basins. Basin effects are modeled using a 3D finite difference program to generate synthetic seismograms. Results will be used to improve the Seattle and Portland 3D velocity models and to better understand and predict amplification of strong motion. We also plan similar analyses

  16. Integrating multi-scale geophysical and drill-core data to improve hydraulic characterization of continental sedimentary basins

    NASA Astrophysics Data System (ADS)

    Kukowski, Nina; Methe, Pascal; Goepel, Andreas

    2017-04-01

    Physical properties of rocks in the uppermost continental crust e.g. sedimentary basins are very heterogeneously distributed and anisotropic making it necessary to perform advanced post processing techniques on geophysical data. Whereas e.g. electrical resistivity or seismic tomography allow only for identifying physical properties' variability on a scale from roughly several tens of metres to several hundred metres, drill cores reveal physical heterogeneity on the cm-scale. To study the impact of small scale acoustic and hydraulic heterogeneity on fluid flow in a sedimentary basin we use combined data sets from the Thuringian Basin in Germany, a small southern extension of the North German Basin characterised by Permian to Triassic sediments. Our data sets consist of three reflection seismic lines acquired within the framework of the multidisciplinary project INFLUINS (INtegrated FLUid dynamics IN Sedimentary basins) and as site survey for deep drilling, geophysical logging data from a 1,179 m deep drill hole in the centre of the Thuringian Basin, and Multi Sensor Core Logger (MSCL) data of the cores recovered from this drill hole. Geophysical borehole logging was performed immediate after drilling on the highest vertical resolution (about 10 cm) possible using state of the art commercial logging tools. MSCL-data were acquired at an even higher resolution of about 1 to 2 cm , which enables both, calibrating logging data and zooming in the spatial heterogeneity of physical properties. These measurements are complemented with laboratory measurements of rock physical properties (e.g. thermal conductivity, permeability) using selected core samples. Here, we mainly focus on seismic (sonic velocity, density) and hydraulic (porosity, permeability) parameters. This multi-methodological approach allows us on the one hand to estimate improved local to regional average values for physical parameters but most importantly also to highlight the role of thin layers, the physical

  17. Overpressure Evolution during Sedimentary Basin Diagenesis: Implications for Hydrocarbon Transport By Solitary Waves

    NASA Astrophysics Data System (ADS)

    Joshi, A.; Appold, M. S.

    2014-12-01

    Recent research has shown solitary waves to be capable of transporting fluids through porous media at rates orders of magnitude faster than predicted from Darcy's law. Solitary waves are expressed as regions of high fluid pressure and porosity. The waves form and propagate where permeability is a sensitive function of effective stress, fluid pressure approaches lithostatic pressure, and the rate of fluid pressure generation is rapid compared to the rate of fluid pressure diffusion. The purpose of the present study was to investigate the pressure generation rates that can develop in a sedimentary basin over a range of possible geologic conditions so that the potential for solitary wave formation can be assessed. Pressure generation rates were calculated for a generic sedimentary basin by constructing a two-dimensional numerical model that treated sediment deposition, compaction, heat flow, kerogen maturation, hydrocarbon formation, and the flow of water, oil, and gas. The results showed compaction disequilibrium and hydrocarbon formation to be the two principal causes of pressure generation, respectively. Pressure generation rates for typical sedimentary basinal conditions were found to be on the order of 1's of Pa/year, up to a maximum of ~400 Pa/year under the most favorable pressure generating conditions. These pressure generation rates would be sufficient to form oil-saturated solitary waves but too low to form methane-saturated solitary waves because of the higher rate of methane pressure diffusion compared to oil, due to methane's lower viscosity. To form methane-saturated solitary waves, pressure generation rates of at least ~1800 Pa/year are needed, which are unlikely to be produced by sedimentary basin diagenetic processes, but could possibly be produced by earthquakes.

  18. Early Tertiary subsidence and sedimentary facies - Northern Sirte Basin, Libya

    SciTech Connect

    Gumati, Y.D.; Kanes, W.H.

    1985-12-01

    The subsidence curves and subsidence rate curves for the Sirte basin, constructed from the stratigraphic record, show that subsidence was continuous throughout Late Cretaceous and Tertiary times, reaching a maximum during the Paleocene and Eocene, when a major reactivation of faults occurred. Shales and carbonates were deposited during all of the Late Cretaceous and Tertiary. Abrupt lateral facies changes occur from the platform areas toward the deeper troughs along with steep downdip thickening. The absence of upper Paleozoic and lower Mesozoic sediments suggests that the area was domed, faulted, and eroded during the late Mesozoic. As a result of crustal extension during the Paleocene, a marked lithologic and structural change occurred. The Heira Shale succeeded the Kalash Limestone in the Marada trough. Reactivation of the earlier faults, accompanied by an increase in the sediment supply from the south, caused these lower Paleocene shales to cover the entire area, with the exception of the old highs where carbonate deposition continued. An intercalation of shales and carbonates provides a sensitive indicator of change of depth and sediment type. 14 figures.

  19. Early Tertiary subsidence and sedimentary facies - northern Sirte Basin, Libya

    SciTech Connect

    Gumati, Y.D.; Kanes, W.H.

    1985-01-01

    The subsidence curves and subsidence rate curves for the Sirte basin, constructed from the stratigraphic record, show that subsidence was continuous throughout Late Cretaceous and Tertiary times, reaching a maximum during the Paleocene and Eocene, when a major reactivation of faults occurred. Shales and carbonates were deposited during all of the Late Cretaceous and Tertiary. Abrupt lateral facies changes occur from the platform areas toward the deeper troughs along with steep downdip thickening. These conditions were probably assisted by contemporaneous faulting along structurally weak hinge lines where the dominant structural elements are normal step faults. The absence of upper Paleozoic and lower Mesozoic sediments suggests that the area was domed, faulted, and eroded during the late Mesozoic. As a result of crustal extension during the Paleocene, a marked lithologic and structural change occurred. The Heira Shale succeeded the Kalash Limestone in the Marada trough. Reactivation of the earlier faults, accompanied by an increase in the sediment supply from the south, caused these lower Paleocene shales to cover the entire area, with the exception of the old highs where carbonate deposition continued. An intercalation of shales and carbonates provides a sensitive indicator of change of depth and sediment type.

  20. Modelling hydrothermal venting in volcanic sedimentary basins: Impact on hydrocarbon maturation and paleoclimate

    NASA Astrophysics Data System (ADS)

    Iyer, Karthik; Schmid, Daniel W.; Planke, Sverre; Millett, John

    2017-06-01

    Vent structures are intimately associated with sill intrusions in sedimentary basins globally and are thought to have been formed contemporaneously due to overpressure generated by gas generation during thermogenic breakdown of kerogen or boiling of water. Methane and other gases generated during this process may have driven catastrophic climate change in the geological past. In this study, we present a 2D FEM/FVM model that accounts for 'explosive' vent formation by fracturing of the host rock based on a case study in the Harstad Basin, offshore Norway. Overpressure generated by gas release during kerogen breakdown in the sill thermal aureole causes fracture formation. Fluid focusing and overpressure migration towards the sill tips results in vent formation after only few tens of years. The size of the vent depends on the region of overpressure accessed by the sill tip. Overpressure migration occurs in self-propagating waves before dissipating at the surface. The amount of methane generated in the system depends on TOC content and also on the type of kerogen present in the host rock. Generated methane moves with the fluids and vents at the surface through a single, large vent structure at the main sill tip matching first-order observations. Violent degassing takes place within the first couple of hundred years and occurs in bursts corresponding to the timing of overpressure waves. The amount of methane vented through a single vent is only a fraction (between 5 and 16%) of the methane generated at depth. Upscaling to the Vøring and Møre Basins, which are a part of the North Atlantic Igneous Province, and using realistic host rock carbon content and kerogen values results in a smaller amount of methane vented than previously estimated for the PETM. Our study, therefore, suggests that the negative carbon isotope excursion (CIE) observed in the fossil record could not have been caused by intrusions within the Vøring and Møre Basins alone and that a contribution

  1. Miocene-Pliocene transition in the southern Cyprus basins: The sedimentary expression of regional tectonic events

    SciTech Connect

    Orzag-Sperber, F.; Rouchy, J.M. )

    1988-08-01

    In the southern part of Cyprus, a Maastrichtian-Pleistocene sedimentary area fringes Troodos Mountain, a fragment of an ancient crust. During the Neogene, three basins formed in this area: Polemi, Pissouri, and Psematismenos. A deep marine condition has prevailed since the Maastrichtian. During the Paleocene and early Miocene, the sea gradually become shallower until the Messinian, where the most spectacular sedimentary event concerns the deposition of evaporites contemporaneous with other Mediterranean evaporites. Some sedimentary phenomena express the tectonic instability during the upper Miocene. A well-known tectonic event affecting the east Mediterranean region generally referred to as the Miocene-Pliocene phase occurs at the Miocene-Pliocene limit. Recent sedimentological studies indicate this event is in fact complex. The Tortonian-lower Pliocene period is marked by a constraint involving an N20 distension in the Polemi and Pissouri basins and an N100 distension in the Psematismenos basin. Sedimentologic studies have demonstrated three tectonic pulsations during the Messinian prior to the Pliocene transgression. These are expressed by two episodes of seismic brecciation and a paleoemersion indicated by paleosols and detrital discharges. These phenomena suggest brief tectonic instability during the Messinian. Microtectonic studies reveal that the main change in tectonic constraint does not coincide with the Miocene-Pliocene contact but occurs at the top of the lower Pliocene.

  2. Amplification and Attenuation in the Los Angeles and Kanto Sedimentary Basins using the Ambient Seismic Field

    NASA Astrophysics Data System (ADS)

    Denolle, M.; Prieto, G.; Lawrence, J. F.; Beroza, G. C.; Hirata, N.; Nakagawa, S.; Miyake, H.; Kasahara, K.; Sakai, S.; Aketagawa, T.; Kimura, H.

    2010-12-01

    Ground motion prediction is traditionally estimated in seismic hazard analysis using parametric scaling relations, which are often referred to as "attenuation relations." Increasingly, seismologists are turning to simulation-based hazard analysis. There are at least two reasons for this. First, it allows seismologists to overcome the scarcity of data from large events in the data. Second, it exploits our growing knowledge of the geological complexity of the Earth's crust and our ability to model wave propagation through it. The accuracy of these simulations is critical to their use for risk reduction, but is limited by our incomplete knowledge of the elastic and anelastic structure of the subsurface. The situation is particularly acute for sedimentary basins that underlie densely populated urban centers such as Los Angeles and Tokyo, both because the exposure is so high, and because it is difficult to obtain new images of Earth structure in urban settings. In this study, we show how ambient seismic field analysis can improve this situation. We take the advantage of the dense seismic networks in those areas and use 9 months of continuous records for about 180 stations from the Southern Californian Seismic Networks for Los Angeles and 6 months of a combination of 190 MeSO-net stations and 110 Hi-net instruments in Tokyo area. We estimate the basin amplification of these comparable urban centers with ambient field transfer function, or impulse response. The ambient seismic field also provides constraints on the attenuation signal in surface waves, and hence on the anelastic structure of the Earth. We exploit this by using the real part of the complex coherence to estimate the attenuation coefficient of Rayleigh waves, and from it variations in the anelastic structure. We acknowledge the support by the Special Project for Earthquake Disaster Mitigation in Tokyo Metropolitan Area from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

  3. Early to Middle Triassic sedimentary records in the Youjiang Basin, South China: Implications for Indosinian orogenesis

    NASA Astrophysics Data System (ADS)

    Qiu, Liang; Yan, Dan-Ping; Yang, Wen-Xin; Wang, Jibin; Tang, Xiangli; Ariser, Shahnawaz

    2017-06-01

    The Indosinian orogeny marks the termination of marine deposition and the accumulation of lower Permian to Late Triassic clastic sediments in the Youjiang Basin, South China Block. Major and trace element compositions of Early to Middle Triassic sedimentary clastic rocks from Youjiang Basin were analysed to constrain their provenance and tectonic setting. Argillaceous samples have low SiO2 (average 56.95 wt.%), Al2O3 (average 15.15 wt.%), and Fe2O3T + MgO (average 11.54 wt.%) contents, and high K2O/Na2O (average 15.61) and Al2O3/SiO2 (average 0.27) ratios, similar to mudstones from continental arc basins. Arenaceous samples have moderate SiO2 (average 76.98 wt.%), Al2O3 (average 8.41 wt.%), and Fe2O3T + MgO (average 5.29 wt.%) contents, and moderate Al2O3/SiO2 (average 0.11) and K2O/Na2O (average 15.26) ratios, identical to those of graywackes from continental island arcs or active continental margins. Both the argillaceous and arenaceous samples have low CIA values (57-85) and relatively high ICV values (0.69-2.11), indicating that the source rocks experienced weak chemical weathering and the sedimentary detritus was derived from an immature source. Compared with late Permian to Early Triassic South China granitoids and upper crust, the samples have lower contents of high-field-strength elements (e.g., Zr, Hf, Nb, and Ta) and large ion lithophile elements (e.g., Rb, Sr, Ba, Th, U, and Pb). However, their relatively high Rb concentrations (>51 ppm), and low Rb/Sr (0.16-4.19) and Th/U (2.66-5.21) ratios, are indicative of an igneous source from a continental arc that underwent weak chemical weathering. Both the argillaceous and arenaceous samples are moderately enriched in light rare earth elements and show relatively flat chondrite-normalized heavy rare earth element patterns (LaN/YbN = 6.61-17.35; average 10.61) with strong negative Eu anomalies (Eu/Eu* = 0.54-0.89; average 0.73). In tectonic discrimination diagrams, including Th-Sc-Zr/10 and La-Th-Sc plots, the

  4. Seismic valve as the main mechanism for sedimentary fluid entrapment within extensional basin: example of the Lodève Permian Basin (Hérault, South of France).

    NASA Astrophysics Data System (ADS)

    Laurent, D.; Lopez, M.; Chauvet, A.; Imbert, P.; Sauvage, A. C.; Martine, B.; Thomas, M.

    2014-12-01

    During syn-sedimentary burial in basin, interstitial fluids initially trapped within the sedimentary pile are easily moving under overpressure gradient. Indeed, they have a significant role on deformation during basin evolution, particularly on fault reactivation. The Lodève Permian Basin (Hérault, France) is an exhumed half graben with exceptional outcrop conditions providing access to barite-sulfides mineralized systems and hydrocarbon trapped into rollover faults of the basin. Architectural studies shows a cyclic infilling of fault zone and associated S0-parallel veins according to three main fluid events during dextral/normal faulting. Contrasting fluid entrapment conditions are deduced from textural analysis, fluid inclusion microthermometry and sulfide isotope geothermometer: (i) the first stage is characterized by an implosion breccia cemented by silicifications and barite during abrupt pressure drop within fault zone; (ii) the second stage consists in succession of barite ribbons precipitated under overpressure fluctuations, derived from fault-valve action, with reactivation planes formed by sulphide-rich micro-shearing structures showing normal movement; and (iii) the third stage is associated to the formation of dextral strike-slip pull-apart infilling by large barite crystals and contemporary hydrocarbons under suprahydrostatic pressure values. Microthermometry, sulfide and strontium isotopic compositions of the barite-sulfides veins indicate that all stages were formed by mixing between deep basinal fluids at 230°C, derived from cinerite dewatering, and formation water from overlying sedimentary cover channelized trough fault planes. We conclude to a polyphase history of fluid trapping during Permian synrift formation of the basin: (i) a first event, associated with the dextral strike-slip motion on faults, leads to a first sealing of the fault zone; (ii) periodic reactivations of fault planes and bedding-controlled shearing form the main mineralized

  5. Structure and hydrocarbon potential of sedimentary basins of the far east marginal seas

    SciTech Connect

    Gnibidenko, H. ); Kononov, V. )

    1990-05-01

    Crustal structural of the Bering, Okhotsk Japan, East China, and South China marginal seas consists of continental plates and deep sea basins that are the elements of the lowermost order in the structure of transition zone from the Asia continent to the Pacific Ocean. Two stages are recognized in the crustal evolution of the northwest Pacific transition zone: (1) geosyncline development that began in the pre-Paleozoic and continues to the present within island arcs; and (2) quasiplatform stage that began in the late Cretaceous and continues to the Holocene within shelf plates. The continental margins of the Far East seas consist of Cenozoic terrigenous cover and pre-Cenozoic basement composed of geosyncline rock association. Normal faults control graben features in the basement and develop rift systems. Paleogene subcontinental formations make up the lowermost section of the cover. A major Oligocene-Holocene sequence (marine formations) overlies and smooths rough topography of the basement and creates giant sedimentary basins. Sediment thickness of the basins attains 10 km. Tectonic evolution of the marginal seas implies the shelf plates to be young platforms and deep-sea basins are believed to be parts of the Pacific thalassocraton fenced by island arcs. The tectonic criterion enables us to differ and grade the provinces according to a hydrocarbon potential. Nearly 100 promising sedimentary basins are presently known in the Bering, Okhotst Japan, East China, and South China seas. About ten basins have been identified as hydrocarbon resources. Deep-sea basins also look promising for hydrocarbons. All the economically significant hydrocarbon accumulations in the Far East marginal seas are attributed to the Cenozoic sediment cover. Major resources are concentrated in the Miocene and Pliocene terrigenous sequences composed of progradation facies within the shelf plates.

  6. Sedimentary basins on the connugate margins of South America and Africa

    SciTech Connect

    Moore, G.T. )

    1990-05-01

    An Early Cretaceous spreading system formed the South Atlantic by separating South America from Africa along two subparallel major transform fault systems. The distribution of major sedimentary depocenters is controlled by the complex interplay of two factors: the late Mesozoic-Cenozoic cycle of sea-floor spreading and the legacy of a Precambrian collage of ancient cores that comprised western Gondwana. Three spreading modes created this configuration: rift, transform, and subduction. Each produces a different geometry and tectonic framework for the accumulation of sediment. Rifted margins (60%) contain basins that are elongate, form with their depocenter axes inboard of the ocean-continent transition, and rest on a tectonically complex, foundered basement. Transform margins have abrupt ocean-continent transitions. Such margins (30%) may be sediment starved or contain a thick sedimentary section controlled by the volcanic ridges of transform faults. Off Tierra del Fuego, Burdwood Bank is bounded on the north by a fossil (aseismic) subduction zone. The associated basin is an elongate, deformed accretionary prism of sediments on a gently dipping, faulted oceanic plate. The South Atlantic margins are divisible into 68 basins or segments that collectively contain over 33 {times} 106 km{sup 3} of syn- and postbreakup sediments. The South American margin contains 22 {times} 10{sup 6} km{sup 3} in 46 basins, and the African margin, 11 {times} 10{sup 6} km{sup 3} in 22 basins. Over 65% of the basins have a sediment column greater than 5 km with some depocenters that locally exceed 10 km. The source rock quality and character vary along both margins. The top of the oil generation window averages about 3.3 km; however, due to differing thermal histories, individual basins can depart significantly from this average.

  7. Source and mobility of Rare Earth Elements in a sedimentary aquifer system: Aquitaine basin (Southern France)

    NASA Astrophysics Data System (ADS)

    Negrel, P. J.; Petelet-Giraud, E.; Millot, R.; Malcuit, E.

    2011-12-01

    The study of rare earth elements (REEs) in natural waters initially involved an examination of their occurrence and behavior in seawater and coastal waters such as estuaries. Since the 1990s, REE geochemistry has been applied to continental waters such as rivers and lakes and groundwaters. Rare earth elements) are of great interest because of their unique characteristics and have been used in the study of many geological processes like weathering and water-rock interaction processes, provenance of sediments, etc... With the evolution of analytical techniques like new generation ICP-MS, much attention had been paid towards the water geochemistry of REEs. However, there is a need of more investigations devoted to REEs in large groundwater systems, especially on the understanding of the distribution of REEs and their evolution in such systems. In this frame, large sedimentary aquifer systems often constitute strategic water resources for drinking water supply, agriculture irrigation and industry, but can also represent an energetic resource for geothermal power. Large water abstractions can induce complete modification of the natural functioning of such aquifer systems. These large aquifer systems thus require water management at the basin scale in order to preserve both water quantity and quality. The large Eocene Sand aquifer system of the Aquitaine sedimentary basin was studied through various hydrological, chemical and isotopic tools. This system extends over 116,000 km2 in the South west part of the French territory. The aquifer being artesian in the west of the district and confined with piezometric levels around 250-m depth in the east. The 'Eocene Sands', composed of sandy Tertiary sediments alternating with carbonate deposits, is a multi-layer system with high permeability and a thickness of several tens of metres to a hundred metres. The Eocene Sand aquifer system comprises at least five aquifers: Paleocene, Eocene infra-molassic sands (IMS), early Eocene

  8. Alteration mineralogy and geochemistry as an exploration tool for detecting basement heat sources in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Uysal, Tonguc; Gasparon, Massimo; van Zyl, Jacobus; Wyborn, Doone

    2010-05-01

    The Cooper Basin located in South Australia and Queensland hosts some of the hottest granites in the world at economic drilling depths (240°C at 3.5 km). Investigating the mechanism of heat-producing element enrichment in the Cooper Basin granite is crucial for understanding hot-dry rock geothermal systems and developing exploration strategies. Trace element (by ICP-MS) and stable isotope geochemistry of whole rock granite samples and hydrothermal phyllosilicate alteration minerals separated from the granite and overlying sandstones and mudstones of the Cooper Basin were examined in detail. Granite core samples from relatively shallow depths in Moomba 1 and Big Lake 1 are strongly altered with pervasive sericite (illite) and quartz precipitation, probably associated with intense micro-fracturing and veining. The intensity of hydrothermal alteration is less in deeper samples from Mcleod 1, Jolokia and Habanero 1. Highly altered granites from former holes are substantially enriched in lithophile elements, particularly in Cs, Rb, Be, Th, U and rare earth elements (REE) relative to the upper continental crust (UCC). U and Th contents with concentrations of up to 30 and 144 ppm, respectively, are 10 and 13 times higher than those of the UCC. Comparison of the trace element composition of the same samples dissolved by open beaker acid digestion and high-pressure acid bomb digestion (to dissolve zircon) shows that zircon is not the main repository of U and Th in the Cooper Basin granite. Instead, we propose that the enrichment of heat-producing elements was promoted by a regional hydrothermal event leading to the precipitation of U and Th- bearing minerals such as illite, K-feldspar and thorite. Crystallinity index (illite crystallinity) of the sericite indicates hydrothermal temperatures ranging from 250°C (in Moomba 1 and Big Lake 1) to 350°C (in McLeod 1 and Jolokia 1). In the overlying sedimentary rocks, crystallinity of authigenic illites translates to lower

  9. Sedimentary successions and the onset of the Neoproterozoic Jiangnan sub-basin in the Nanhua rift, South China

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Zhou, Xiaolin; Deng, Qi; Fu, Xiugen; Duan, Taizhong; Guo, Xiumei

    2015-04-01

    Recent results of research from a regional geological survey have demonstrated that the Neoproterozoic Nanhuan strata in the Jiangnan sub-basin in the Nanhua rift in South China are built up of "wedge-shaped strata", which rest transgressively on the metamorphic basement. These strata are grouped, as indicated by our sedimentary facies analysis, into the following four depositional successions (with ten related sedimentary facies associations): (1) continental volcanic depositional succession; (2) continental siliciclastic depositional succession; (3) marine siliciclastic depositional succession; and (4) glacial depositional succession. Compared with the Hunan-Guangxi sub-basin and the Northern Zhejiang sub-basin, the sedimentary processes in the Jiangnan sub-basin are dominated by continental rather than marine facies. However, similar sedimentary successions with identical facies trends can be recognized in all these sub-basins. All the Neoproterozoic basin fills in South China are characterized by a deepening water trend leading from continental to fully marine facies, recording the evolution of a typical rift basin related to the break-up of Rodinia. The crystalline zircons from a rhyolite sample taken from the base part of the first succession in the Jiangnan sub-basin give a mean SHRIMP U-Pb age of 803 ± 9 Ma. The occurrence of the ca. 803 Ma volcanic rocks and the volcaniclastic rocks marks the onset of a new phase of depositional cycles in the Jiangnan sub-basin.

  10. Sedimentary evolution of the Paleozoic basin fill, southeast Turkey

    SciTech Connect

    Tunbridge, I.P. )

    1988-08-01

    The Paleozoic succession of southeast Turkey reaches its thickest development in the Hakkari district. Here, well-exposed Paleozoic rocks of Cambrian to Permian age are more than 5 km thick, representing a punctuated accumulation of clastic and carbonate sediments on the northern margin of the Arabian shield. Lower Cambrian rocks (< 1.5 km thick) are recorded in the Sadan Formation. A range of deltaic and fluviatile facies are present here. These developed as large-scale meandering then later braided river systems, which flowed north from the Arabian shield. Peritidal dolomites of the Koruk Formation follow, succeeded by 1 km of Cambrian-Ordovician storm-swept shelf sandstones and mudstones of the Seyisehir Formation. Following a Middle Ordovician break, a thin (25 m) Ashgillian siliciclastic shelf sea succession occurs, known as the Sort Tepe Formation. Silurian sediments are not found, and the Devonian of the Hakkari district is marked by the Upper Devonian Yiginli Formation. This formation records a 380-m regressive-transgressive fluvial-deltaic couplet, with deltaic conditions terminated by an Early Carboniferous eustatic sea-level rise. This event permitted the development of a 250 m-thick black shale facies (Koprulu Formation), which was succeeded by 130 m of carbonate mound facies (Belek Formation). Thick (2,000 m) carbonate sequences of the Habbur Formation (Permian) mark the start of the thick carbonate sequences which persisted from the late Paleozoic through the Mesozoic in the region.

  11. Identification of a late Quaternary alluvial-aeolian sedimentary sequence in the Sichuan Basin, China

    NASA Astrophysics Data System (ADS)

    Feng, Jin-Liang; Ju, Jian-Ting; Chen, Feng; Hu, Zhao-Guo; Zhao, Xiang; Gao, Shao-Peng

    2016-03-01

    The late Quaternary sedimentary sequence in the northwestern part of the Sichuan Basin consists of five lithological units and with increasing depth include the: Chengdu Clay; Brown Clay; Red Clay; Sandy Silt; and basal Muddy Gravel. The genesis, provenance and age of the sediments, as well as the possible presence of hiatuses within this sequence are debated. Measurements of grain-size, magnetic susceptibility, quartz content, quartz δ18O values, element composition, and Sr-Nd isotopic concentrations of samples from a typical sedimentary sequence in the area provides new insights into the genesis and history of the sequence. The new data confirm that the sediments in study site are alluvial-aeolian in origin, with basal alluvial deposits overlain by aeolian deposits. Like the uppermost Chengdu Clay, the underlying Brown Clay and Red Clay are aeolian in origin. In contrast, the Silty Sand, like the basal Muddy Gravel, is an alluvial deposit and not an aeolian deposit as previously thought. Moreover, the succession of the aeolian deposits very likely contains two significant sedimentary hiatuses. Sedimentological analysis demonstrates that the source materials for the aeolian deposits in the northwestern part of the Sichuan Basin and those on the eastern Tibetan Plateau are different. Furthermore, the loess deposits on the eastern Tibetan Plateau are derived from heterogeneous local sources.

  12. Three depositional states and sedimentary processes of the western Taiwan foreland basin system

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Jung; Wu, Pei-Jen; Yu, Ho-Shing

    2010-05-01

    The western Taiwan foreland basin formed during the Early Pliocene as the flexural response to the loading of Taiwan orogen on the Eurasian plate. What makes Taiwan interesting is the oblique collision, which allows the foreland basin to be seen at different stages in its evolution at the present day. Due to oblique arc-continent collision from north to south, the western Taiwan foreland basin has evolved into three distinct subbasins: an over-filled basin proximal to the Taiwan orogen, mainly distributed in the Western Foothills and Coastal Plain provinces, a filled basin occupying the shallow Taiwan Strait continental shelf west of the Taiwan orogen and an under-filled basin distal to the Taiwan orogen in the deep marine Kaoping Slope offshore southwest Taiwan, respectively. The over-filled depositional phase is dominated by fluvial environments across the structurally controlled piggy-back basins. The filled depositional state in the Taiwan Strait is characterized by shallow marine environments and is filled by Pliocene-Quaternary sediments up to 4,000 m thick derived from the Taiwan orogen with an asymmetrical and wedge-shaped cross section. The under-filled depositional state is characteristic of deep marine environments in the wedge-top basins accompanied by active structures of thrust faults and mud diapers. Sediments derived from the Taiwan orogen have progressively filled the western Taiwan foreland basin across and along the orogen. Sediment dispersal model suggests that orogenic sediments derived from oblique dischronous collisional highlands are transported in two different ways. Transport of fluvial and shallow marine sediments is perpendicular to hill-slope and across-strike in the fluvial and shallow marine environments proximal to the orogen. Fine-grained sediments mainly longitudinally transported into the deep marine environments distal to the orogen. The present sedimentary processes in the over-filled basin on land are dominated by fluvial

  13. Tectonics of Chukchi Sea Shelf sedimentary basins and its influence on petroleum systems

    NASA Astrophysics Data System (ADS)

    Agasheva, Mariia; Antonina, Stoupakova; Anna, Suslova; Yury, Karpov

    2016-04-01

    The Chukchi Sea Shelf placed in the East Arctic offshore of Russia between East Siberian Sea Shelf and North Slope Alaska. The Chukchi margin is considered as high petroleum potential play. The major problem is absence of core material from drilling wells in Russian part of Chukchi Shelf, hence strong complex geological and geophysical analyses such as seismic stratigraphy interpretation should be provided. In addition, similarity to North Slope and Beaufort Basins (North Chukchi) and Hope Basin (South Chukchi) allow to infer the resembling sedimentary succession and petroleum systems. The Chukchi Sea Shelf include North and South Chukchi Basins, which are separated by Wrangel-Herald Arch and characterized by different opening time. The North Chukchi basin is formed as a general part of Canada Basin opened in Early Cretaceous. The South Chukchi Basin is characterized by a transtensional origin of the basin, this deformation related to motion on the Kobuk Fault [1]. Because seismic reflections follow chronostratigraphic correlations, it is possible to achieve stratigraphic interpretation. The main seismic horizons were indicated as: PU, JU, LCU, BU, mBU marking each regional unconformities. Reconstruction of main tectonic events of basin is important for building correct geological model. Since there are no drilling wells in the North and South Chukchi basins, source rocks could not be proven. Referring to the North Chukchi basin, source rocks equivalents of Lower Cretaceous Pebble Shale Formation, Lower Jurassic Kingdak shales and Upper Triassic Shublik Formation (North Slope) is possible exhibited [2]. In the South Chukchi, it is possible that Cretaceous source rocks could be mature for hydrocarbon generation. Erosions and uplifts that could effect on hydrocarbon preservation was substantially in Lower Jurassic and Early Cretaceous periods. Most of the structures may be connected with fault and stratigraphy traps. The structure formed at Wrangel-Herald Arch to

  14. Links between sedimentary basin development and Pacific basin plate kinematics recorded in Jurassic to Miocene strata on the western Alaska Peninsula

    NASA Astrophysics Data System (ADS)

    Finzel, E.; Ridgway, K.

    2016-12-01

    Late Jurassic to Miocene strata exposed on the western Alaska Peninsula record major changes in plate dynamics and sedimentary basin development along the northern Pacific region. These changes include Late Jurassic to Late Cretaceous accretion of the Wrangellia composite terrane (WCT), establishment of a Late Cretaceous continental volcanic arc, and middle Eocene Pacific plate reorganization and subduction initiation marked by the Alaska Peninsula-Aleutian volcanic arc. Stratigraphic descriptions and detrital zircon geochronology allow reconstruction of sediment dispersal and basinal response to these plate scale events. Upper Jurassic strata contain a dominant population of Late Triassic-Late Jurassic detrital zircons that reflect sediment input from the adjacent oceanic Talkeetna arc located to the north into a marine forearc basin on the outboard side of the WCT. The dominant population of 180 to 140 Ma detrital zircons is related to a large magmatic flux event that extended throughout the northwestern Cordillera. By Late Cretaceous time, after final suturing of the WCT, detrital zircon ages indicate the presence of a new continental volcanic arc system with minor sediment input from older inboard terranes. With final subduction of the Resurrection plate during early Eocene time, the southern margin of the northwestern Cordillera was again reconfigured. Along the western Alaska Peninsula, the Aleutian and Meshik volcanic arcs initiated in response to a shift toward more orthogonal subduction. These arcs are part of a middle-late Eocene time and extend over 3,000 km on the northern rim of the Pacific basin. The basinal response to this event is a shift from nonmarine to marine depositional systems and to a southerly provenance. Middle Eocene through Miocene strata have detrital zircon ages that indicate recycling of the older Mesozoic forearc strata into a developing backarc basin. Dynamic subsidence associated with the change in subduction parameters and

  15. A modern analog for carbonate source-to-sink sedimentary systems: the Glorieuses archipelago and adjacent basin (SW Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Jorry, S.; Jouet, G.; Prat, S.; Courgeon, S.; Le Roy, P.; Camoin, G.; Caline, B.

    2014-12-01

    This study presents the geomorphological and sedimentological analysis of a modern carbonate source-to-sink system located north of Madagascar (SW Indian Ocean). The sedimentary system is composed of an isolated carbonate platform sited on top of a seamount rising steeply from the seabed located at 3000 m water depth. The slope of the seamount is incised by canyons, and meandering channels occur above lobbed sedimentary bodies at the foot of the slope. The dataset consists of dredges, sediment piston cores, swath bathymetry and seismic (sparker and 2D high-resolution) lines collected from inner platform (less than 5 m deep) to the adjacent deep sedimentary basin. Particle size analysis and composition of carbonate grains are used to characterize the distribution and heterogeneity of sands accumulated on the archipelago. Main results show that composition of carbonate sediments is dominated by segments of Halimeda, large benthic foraminifera, coral debris, molluscs, echinoderms, bryozoans and sponges. According to the shape and the position of sandwaves and intertidal sandbars developed in the back-barrier reef, the present organization of these well-sorted fine-sand accumulations appears to be strongly influenced by flood tidal currents. Seismic lines acquired from semi-enclosed to open lagoon demonstrate that most of the sediment is exported and accumulated along the leeward margin of the platform, which is connected to a canyon network incising the outer slope. Following the concept of highstand shedding of carbonate platforms (Schlager et al., 1994), excess sediment is exported by plumes and gravity flows to the adjacent deep sea where it feeds a carbonate deep-sea fan. Combined observations from platform to basin allow to explain how the Glorieuses carbonate source to sink system has evolved under the influence of climate and of relative sea-level changes since the last interglacial.

  16. Correlation between plate motions and tectonic subsidence of sedimentary basins in Africa

    SciTech Connect

    Janssen, M.E. )

    1993-09-01

    From the early Mesozoic until the Holocene, the African continent was generally in a state of extension, based on plate tectonic reconstructions and sedimentary basin subsidence studies. Beginning with the breakup of Gondwana in the Permian-Triassic, this resulted in the formation of the present-day African continental margins and a series of intracontinental rift basins, located mainly on older (late Proterozoic) shear zones. Numerous wells from marginal, as well as intracontinental rift basins, have been backstripped to elucidate their Mesozoic and Tertiary tectonic histories. They show a generally consistent patterns of subsidence and uplift phases in all basins. During the evolution of these basins, the direction of African plate motion changed several times. This was related to the differential opening of the central and south Atlantic oceans, changes in spreading rates in both the Atlantic and Indian oceans, and the collision between Africa and Europe. Episodes of compressional deformation related to these plate tectonic changes are revealed in backstripped tectonic subsidence curves.

  17. The petroleum habitat in the post-rift sequences in the Brazilian sedimentary basins

    SciTech Connect

    De Figueiredo, A.M.F.D.; Fernandes, G.J.F.; Guimaraes, P.T.M. )

    1991-03-01

    The post-rift sedimentary strata of the Brazilian coastal basins are made of two main sequences: the evaporite and carbonatic Albian-Aptian sequence, and the open-marine Late Albian to Recent sequence, both related to the opening of the South Atlantic Ocean. More than 40 billion barrels of oil-equivalent in place has been found in these sequences, mostly in siliciclastic reservoirs above and below the Aptian salt beds. The productive basins are Campos, Espirito Santo, Sergipe-Alagoas, Potiguar, Ceara, and Santos, but the first one is responsible for more than 60% of the original oil in place discovered in these basins. The hydrocarbon origin, migration, and accumulation models in these sequences are discussed and exemplified by some giant oil fields of Campos and Sergipe-Alagoas basins, where oil is trapped in Aptian conglomerates, Albian carbonates, and Upper Cretaceous to Tertiary turbidite sandstones. The cumulative production in these sequences reaches 958.6 million barrels and the proved exploitable reserve amounts reach 2.7 billion barrels of oil-equivalent. Petrobras' exploratory forecast indicates that the post-rift sequences are the most prolific ones in the Brazilian marginal basins. The oil-equivalent that is expected to be discovered, particularly in deep water areas, where giant oil fields (as the Marlim field) have been found, exceeds the amount that has been discovered until now.

  18. Maps showing sedimentary basins, surface thermal maturity, and indications of petroleum in the Central Alaska Province

    USGS Publications Warehouse

    Troutman, Sandra M.; Stanley, Richard G.

    2003-01-01

    This publication includes two maps (at 1:2,500,000 scale) and a pamphlet that describe sedimentary basins, surface thermal maturity, and 95 reported occurrences of petroleum in natural seeps, wells, and rock outcrops in central Alaska. No commercial petroleum production has been obtained from central Alaska, in contrast to the prolific deposits of oil and gas that have been found and developed in northern Alaska and the Cook Inlet region. Nevertheless, confirmed indications of petroleum in central Alaska include (1) natural seeps of methane gas on the Yukon Delta; (2) occurrences of methane gas in wells in the Bethel, Kotzebue, Nenana, Northway, and Yukon Flats basins; (3) oil and methane gas in seeps and wells in Norton Sound; (4) small quantities of liquid and solid hydrocarbons associated with mercury ore in the Kuskokwim Mountains; (5) oil shale and numerous occurrences of bitumen in the Kandik area; and (6) tasmanite, a form of oil shale, in the uplands north of Yukon Flats.

  19. Tectonic-sedimentary evolution of the eastern Brazilian marginal basins: Implications in their petroleum systems

    SciTech Connect

    Francisco, N.F.; Azambuja, N.C.; Mello, M.R. )

    1993-02-01

    A geological survey of eastern Brazilian marginal basins using sedimentological, tectonic and geochemical data has been carried out. The almost 4000 km long set of basins can be classified as component of a typical divergent, mature Atlantic-continental margin. Based on their tectonic-sedimentary sequence, they can be linked to a single evolutionary history, which can be divided in three main stages: pre-rift, rift, and drift. The integration of all data allowed the characterization of two major petroleum systems that represent about 90% of the known Brazilian hydrocarbons reserves: (1) the rift (Early Cretaceous) and the drift (Late Cretaceous-Paleogene). With respect to the oil-in-place volume and production, the most significant one is the drift system associated with the siliciclastic deep water turbidites reservoirs deposited in bathyal environments. Such reservoirs are clearly controlled by a favorable relationship of stratigraphic and tectonic settings.

  20. Devonian-Permian sedimentary basins and paleogeography of the Eastern Russian Arctic: An overview

    NASA Astrophysics Data System (ADS)

    Ershova, Victoria B.; Prokopiev, Andrei V.; Khudoley, Andrey K.

    2016-11-01

    The Arctic basins attract broad international interest because of the region's potentially significant undiscovered hydrocarbon resources. The Russian High Arctic is mostly represented by broad shelves, with a few wells drilled only in its western part (Kara and Barents shelves). This contribution provides an overview of the geological setting, stratigraphy, paleogeography, and tectono-sedimentary evolution of the middle-late Paleozoic basins of the Eastern Russian Arctic, including: Severnaya Zemlya, the New Siberian Islands, northern Siberia, the Taimyr and Chukotka peninsulas, and Wrangel Island. Reconstructing the geological evolution of the Eastern Russian Arctic during the middle-late Paleozoic is very difficult because the region was overprinted by a number of late Paleozoic to early Mesozoic tectonic events.

  1. A low-temperature hydrothermal maturation mechanism for sedimentary basins associated with volcanic rocks

    NASA Astrophysics Data System (ADS)

    Summer, Neil S.; Verosub, Kenneth L.

    Data from sediments associated with volcanic rocks around the world demonstrate that a generally unrecognized maturation mechanism is operating in certain geologically active areas. This mechanism is hydrothermal in nature and involves the transport of heat away from intrusive bodies or deep penetrating faults by laterally-flowing aquifers. The mechanism accounts for regional maturation and diagenetic effects which cannot be explained by conductive heat transfer. In many cases economically important hydrocarbon accumulations can be associated with volcanism via a hydrothermal maturation model, wherein thermal fluids playa major role in the maturation of source rocks and assist in migration of the evolved hydrocarbons. Applying the model would not only give new insights into the thermal history of basin sediments but may assist in determining areas of highest exploration potential. Overall, volcanism has played a larger role in the thermal maturation of certain sedimentary basins than has previously been assumed.

  2. Late Neogene sedimentary facies and sequences in the Pannonian Basin, Hungary

    USGS Publications Warehouse

    Juhasz, E.; Phillips, L.; Muller, P.; Ricketts, B.; Toth-Makk, A.; Lantos, M.; Kovacs, L.O.

    1999-01-01

    This paper is part of the special publication No.156, The Mediterranean basins: Tertiary extension within the Alpine Orogen. (eds B.Durand, L. Jolivet, F.Horvath and M.Seranne). Detailed sedimentological, facies and numerical cycle analysis, combined with magnetostratigraphy, have been made in a number of boreholes in the Pannonian Basin, in order to study the causes of relative water-level changes and the history of the basin subsidence. Subsidence and infilling of the Pannonian Basin, which was an isolated lake at that time occurred mainly during the Late Miocene and Pliocene. The subsidence history was remarkably different in the individual sub-basins: early thermal subsidence was interrupted in the southern part of the basin, while high sedimentation rate and continuous subsidence was detected in the northeastern sub-basin. Three regional unconformities were detected in the Late Neogene Pannonian Basin fill, which represent 0.5 and 7.5 Ma time spans corresponding to single and composite unconformities. Consequently two main sequences build up the Late Neogene Pannonian Basin fill: a Late Miocene and a Pliocene one. Within the Late Miocene sequence there are smaller sedimentary cycles most probably corresponding to climatically driven relative lake-level changes in the Milankovitch frequency band. Considering the periods, the estimated values for precession and eccentricity in this study (19 and 370 ka) are close to the usually cited ones. In the case of obliquity the calculated period (71 ka) slightly deviates from the generally accepted number. Based on the relative amplitudes of oscillations, precession (sixth order) and obliquity (fifth order) cycles had the most significant impact on the sedimentation. Eccentricity caused cycles (fourth order) are poorly detectable in the sediments. The longer term (third order) cycles had very slight influence on the sedimentation pattern. Progradation, recorded in the Late Miocene sequence, correlates poorly in time

  3. Imaging three-dimensional crustal conductivity structures reflecting continental flood basalt effects hidden beneath thick intracratonic sedimentary basin

    NASA Astrophysics Data System (ADS)

    Padilha, Antonio L.; Vitorello, Ícaro; Antunes, Cassio E.; Pádua, Marcelo B.

    2015-07-01

    A large-scale array of long-period magnetic data and a deep-probing magnetotelluric profile were recorded in the intracratonic Paraná sedimentary basin in central eastern South America, which presents a thick and extensive sedimentary-magmatic sequence that allows its basement to be investigated only by indirect methods. Integration of the results from both methods showed that the crust beneath the basin presents several quasi-linear highly conductive channeled zones with limited lateral extent, in coincidence with some of the main tectonic structures recognized at the surface, and a moderate but pervasive lithosphere conductivity enhancement beneath its central part. Upward movement of CO2-bearing volatiles and magmas precipitating highly conducting mineral phases along discrete subvertical fault zones that served as feeder conduits for Early Cretaceous voluminous continental flood basalts was a likely process responsible for the localized conductivity enhancements. Correlation between some of the linear conductive zones and elongated magnetic anomalies and between the maximum depth occurrence of most of these conductive anomalies and the Curie depth at which crustal rocks lose their magnetism gives strong support to interconnected iron oxides (especially magnetite) and iron sulfides (such as pyrrhotite) as the main conductive sources. The moderate bulk conductivity increase in the crust and upper mantle beneath the central part of the basin is unexpected for a postulated cratonic basement and is tentatively associated with impregnation of the lithosphere by conducting minerals related either to widespread tectonic events in the Ordovician or Late Precambrian or to dispersed magmatic residues of an Early Cretaceous magma differentiation contaminating the entire lithosphere.

  4. Early Permian volcano-sedimentary successions, Beishan, NW China: Peperites demonstrate an evolving rift basin

    NASA Astrophysics Data System (ADS)

    Chen, Shi; Guo, Zhaojie; Qi, Jiafu; Zhang, Yuanyuan; Pe-Piper, Georgia; Piper, David J. W.

    2016-01-01

    The Lower Permian volcano-sedimentary Zhesi Group has been investigated in the Hongliuhe and Liuyuan areas in Beishan, China, which is significant for the reconstruction of Late Paleozoic evolution in the southern part of the Central Asian Orogenic Belt. A variety of volcanic facies were distinguished in the Upper Zhesi Group: pillow basalt with interstitial limestone, thin-interbedded limestone and basalt, closely packed pillows, pillow-fragmented hyaloclastite breccia, and peperite. Laser 40Ar/39Ar whole-rock dating of the basalt yielding an age of 277 ± 11 Ma, as well as Early Permian brachiopod fossils in the limestone interbedded with the basalt, indicate that basalt was erupted in the Early Permian. The identification of the peperite and other facies originating from magma-sediment mingling reveals that the basaltic lava flows were derived from autochthonous basaltic magmatism and formed as part of the Lower Permian succession. The peperite also indicates that these subaqueous basaltic lava flows are not dismembered ophiolitic components, but formed in an autochthonous extensional setting in the Early Permian. The clastic rocks in the Lower Zhesi Group underlying the basaltic flows and peperites in the Hongliuhe and Liuyuan areas show a general fining-upwards sequence, indicating that they were deposited in a progressively deepening basin overlying the Devonian Hongliuhe suture zone. Subaqueous volcanism in a rift basin or basins, accompanied by coeval deposition of carbonate sediment and mud, built up the peperite-bearing volcanogenic-sedimentary successions. From among the various tectonic hypotheses for the Beishan region, this study demonstrates that by Early Permian the region was developing post-collisional rift basins.

  5. Sedimentary facies and depositional environments of early Mesozoic Newark Supergroup basins, eastern North America

    USGS Publications Warehouse

    Smoot, J.P.

    1991-01-01

    The early Mesozoic Newark Supergroup consists of continental sedimentary rocks and basalt flows that occupy a NE-trending belt of elongate basins exposed in eastern North America. The basins were filled over a period of 30-40 m.y. spanning the Late Triassic to Early Jurassic, prior to the opening of the north Atlantic Ocean. The sedimentary rocks are here divided into four principal lithofacies. The alluvial-fan facies includes deposits dominated by: (1) debris flows; (2) shallow braided streams; (3) deeper braided streams (with trough crossbeds); or (4) intense bioturbation or hyperconcentrated flows (tabular, unstratified muddy sandstone). The fluvial facies include deposits of: (1) shallow, ephemeral braided streams; (2) deeper, flashflooding, braided streams (with poor sorting and crossbeds); (3) perennial braided rivers; (4) meandering rivers; (5) meandering streams (with high suspended loads); (6) overbank areas or local flood-plain lakes; or (7) local streams and/or colluvium. The lacustrine facies includes deposits of: (1) deep perennial lakes; (2) shallow perennial lakes; (3) shallow ephemeral lakes; (4) playa dry mudflats; (5) salt-encrusted saline mudflats; or (6) vegetated mudflats. The lake margin clastic facies includes deposits of: (1) birdfoot deltas; (2) stacked Gilbert-type deltas; (3) sheet deltas; (4) wave-reworked alluvial fans; or (5) wave-sorted sand sheets. Coal deposits are present in the lake margin clastic and the lacustrine facies of Carnian age (Late Triassic) only in basins of south-central Virginia and North and South Carolina. Eolian deposits are known only from the basins in Nova Scotia and Connecticut. Evaporites (and their pseudomorphs) occur mainly in the northern basins as deposits of saline soils and less commonly of saline lakes, and some evaporite and alkaline minerals present in the Mesozoic rocks may be a result of later diagenesis. These relationships suggest climatic variations across paleolatitudes, more humid to the

  6. The supra-detachment tectono-sedimentary record of rifted margins: the example of the Los Barriles Basin, SE Baja California Sur.

    NASA Astrophysics Data System (ADS)

    Masini, Emmanuel; Robin, Cécile; Geoffroy, Laurent; Strzerzynski, Pierre

    2010-05-01

    The study of rifted margins have shown that the main controlling structures are changing from classical high-angle faults to low-angle detachment fault dominated extension when the crust thins to less than 10 km, which is the case in hyper-extended, magma-poor rifted margins. While the stratigraphic record related to classical high-angle faulting is well constrained, little is known about the tectono-sedimentary evolution of hyper-extended rift systems. A major question remains, how supra-detachment tectono-sedimentary systems are recorded in the stratigraphic record? This remains largely unexplored and must be better constrained by observations. In our poster, we present preliminary results from our study of a rift basin floored by a low-angle detachment system exposed at the southeastern edge of the Baja California Peninsula in the so-called Los Barriles area in the Gulf of California. This area represents one of the best examples of an active transtensional rift system from which the tectono-sedimentary evolution of the rift to drift transition can be studied in the field. The syn-tectonic sedimentary sequence is floored by a detachment fault and is limited oceanward by an extensional allochthon. The syn- to post-tectonic stratigraphy can be summarized into 4 main formations: (1) The Pescadero fluvial fm. (no available ages) evolves upsection from poorly organized polymictic in components and faulted breccias to more granitic and stratified conglomerates. It overlies the extensional allochthon and is tilted continentwards. The channel incisions show EW paleoflows and the upper Pescadero fm. is transitional to the following Refugio fm. (2) The overlying Refugio fm. (Lower Pliocene) occurs as thick marine sandy deposits within the basin axis, is granitic in composition and has average paleocurrents directions trending N-S. The upper part of the fm. is transitional to the following Barriles fm. (3) The Barriles fm. (Upper Miocene - Lower Pleistocene) occurs as very

  7. The structure and stratigraphy of the sedimentary succession in the Swedish sector of the Baltic Basin: New insights from vintage 2D marine seismic data

    NASA Astrophysics Data System (ADS)

    Sopher, Daniel; Erlström, Mikael; Bell, Nicholas; Juhlin, Christopher

    2016-04-01

    We present five interpreted regional seismic profiles, describing the full sedimentary sequence across the Swedish sector of the Baltic Sea. The data for the study are part of an extensive and largely unpublished 2D seismic dataset acquired between 1970 and 1990 by the Swedish Oil Prospecting Company (OPAB). The Baltic Basin is an intracratonic basin located in northern Europe. Most of the Swedish sector of the basin constitutes the NW flank of a broad synclinal depression, the Baltic Basin. In the SW of the Swedish sector lies the Hanö Bay Basin, formed by subsidence associated with inversion of the Tornquist Zone during the Late Cretaceous. The geological history presented here is broadly consistent with previously published works. We observe an area between the Hanö Bay and the Baltic Basin where the Palaeozoic strata has been affected by transpression and subsequent inversion, associated with the Tornquist Zone during the late Carboniferous-Early Permian and Late Cretaceous, respectively. We propose that the Christiansø High was a structural low during the Late Jurassic, which was later inverted in the Late Cretaceous. We suggest that a fan shaped feature in the seismic data, adjacent to the Christiansø Fault within the Hanö Bay Basin, represents rapidly deposited, coarse-grained sediments eroded from the inverted Christiansø High during the Late Cretaceous. We identify a number of faults within the deeper part of the Baltic Basin, which we also interpret to be transpressional in nature, formed during the Caledonian Orogeny in the Late Silurian-Early Devonian. East of Gotland a number of sedimentary structures consisting of Silurian carbonate reefs and Ordovician carbonate mounds, as well as a large Quaternary glacial feature are observed. Finally, we use the seismic interpretation to infer the structural and stratigraphic history of the Baltic and Hanö Bay basins within the Swedish sector.

  8. Shelf-edge sedimentary systems off Rio de Janeiro State, northern Santos basin-Brazil

    NASA Astrophysics Data System (ADS)

    Maia, R. M. C.; Dos Reis, A. T.; Gorini, C.; Silva, C. G.; Rabineau, M.; Granjeon, D.

    2012-04-01

    elements provide a hint at a prevailing subsidence regime and effective sediment supply into the basin that clearly contrast with the conveyed idea of a sediment-starved and tectonic stable shelf. They naturally raise questions about the nature and origin of sediment supply, since no significant point siliciclastic fluvial source flows directly into the shelf. Stemming from that, we are forced to speculate about: (A) the role of neotectonic movements involving the Serra do Mar coastal mountain ranges to potentially source clastic influx into the basin during the Quaternary, or about the real importance of secondary drainage basins debouching today; and (B) the mechanical nature of a supposed subsidence during the Pliocene and the Quaternary time span (overloading ? sediment compaction ? thermal cooling ?). The interpretation of industrial seismic lines can provide the answers of many of these questions. The next step of this work is to make a stratigraphy model of the sedimentary systems of Santos basin to understand how the ancient creation of accommodation space can influence the recent sedimentary architecture and how is the change in sedimentary influx and the sedimentary records of different orders of cyclicity.

  9. Oil and gas potential of sedimentary basins of the Ural-Mongolian mobile belt

    SciTech Connect

    Dedeyev, V.A.; Aminov, L.Z.

    1993-04-01

    The sedimentary basins of the Ural-Mongolian mobile belt fall into two groups: near-geosynclinal folded and intrageosynclinal folded. In the present structural plan the first group includes two planetary-scale belts of oil and gas accumulation, the Ural and Yenisey. The main regional oil- and gas-bearing complexes of the Ural belt are transgressive middle Devonian-early Frasnian clastic rocks, containing up to 18-20% initial oil and gas reserves in categories A + B + C[sub 1] + C[sub 2]; regressive-transgressive early-middle Visean clastic formations (12-15%); inundational Bashkirian-Visean (22-25%) and Late Carboniferous-Early Permian (21-25%) carbonate rocks. The main regional oil- and gas-bearing complexes of the Yenisey belt are related to mainly clastic transgressive Vendian-early Cambrian rocks (40-50% of initial potential hydrocarbon reserves) and inundational Cambrian evaporite-carbonate formations (up to 25%). All the epi-geosynclinal sedimentary basins belong to the second group; they are mainly heterogenetic and less than 350-370 Ma in age, but there are a few small monogenetic ones up to 40-50 Ma in age.

  10. Modeling of wind gap formation and development of sedimentary basins during fold growth: application to the Zagros Fold Belt, Iran.

    NASA Astrophysics Data System (ADS)

    Collignon, Marine; Yamato, Philippe; Castelltort, Sébastien; Kaus, Boris

    2016-04-01

    Mountain building and landscape evolution are controlled by the interactions between river dynamics and tectonic forces. Such interactions have been largely studied but a quantitative evaluation of tectonic/geomorphic feedbacks remains required for understanding sediments routing within orogens and fold-and-thrust belts. Here, we employ numerical simulations to assess the conditions of uplift and river incision necessary to deflect an antecedent drainage network during the growth of one or several folds. We propose that a partitioning of the river network into internal (endorheic) and longitudinal drainage arises as a result of lithological differences within the deforming crustal sedimentary cover. We show with examples from the Zagros Fold Belt (ZFB) that drainage patterns can be linked to the incision ratio R between successive lithological layers, corresponding to the ratio between their relative erodibilities or incision coefficients. Transverse drainage networks develop for uplift rates smaller than 0.8 mm.yr-1 and -10 < R < 10. Intermediate drainage network are obtained for uplift rates up to 2 mm.yr-1 and incision ratios of 20. Parallel drainage networks and formation of sedimentary basins occur for large values of incision ratio (R >20) and uplift rates between 1 and 2 mm.yr-1. These results have implications for predicting the distribution of sediment depocenters in fold-and-thrust belts, which can be of direct economic interest for hydrocarbon exploration.

  11. Geodynamic evolution and sedimentary infill of the northern Levant Basin: A source to sink-perspective

    NASA Astrophysics Data System (ADS)

    Hawie, N.

    2013-12-01

    Nicolas Hawie a,b,c (nicolas.hawie@upmc.fr) Didier Granjeon c (didier.granjeon@ifpen.fr) Christian Gorini a,b (christian.gorini@upmc.fr) Remy Deschamps c (remy.deschamps@ifpen.fr) Fadi H. Nader c (fadi-henri.nader@ifpen.fr) Carla Müller Delphine Desmares f (delphine.desmares@upmc.fr) Lucien Montadert e (lucien.montadert@beicip.com) François Baudin a (francois.baudin@upmc.fr) a UMR 7193 Institut des Sciences de la Terre de Paris, Université Pierre et Marie Curie/ Univ. Paris 06, case 117. 4, place Jussieu 75252 Paris Cedex 05, France b iSTEP, UMR 7193, CNRS, F-75005, Paris, France c IFP Energies nouvelles, 1-4 avenue du Bois Préau 92852 Rueil Malmaison Cedex, France d UMR 7207, Centre de Recherche sur la Paleobiodiversité et les Paleoenvironnements. Université Pierre et Marie Curie, Tour 46-56 5ème. 4, place Jussieu 75252 Paris Cedex 05, France e Beicip Franlab, 232 Av. Napoléon Bonaparte, 95502 Rueil-Malmaison, France Sedimentological and biostratigraphic investigations onshore Lebanon coupled with 2D offshore reflection seismic data allowed proposing a new Mesozoic-Present tectono-stratigraphic framework for the northern Levant Margin and Basin. The seismic interpretation supported by in-depth facies analysis permitted to depict the potential depositional environments offshore Lebanon as no well has yet been drilled. The Levant region has been affected by successive geodynamic events that modified the architecture of its margin and basin from a Late Triassic to Middle Jurassic rift into a Late Cretaceous subduction followed by collision and Miocene-Present strike slip motion. The interplay between major geodynamic events as well as sea level fluctuations impacted on the sedimentary infill of the basin. During Jurassic and Cretaceous, the Levant Margin is dominated by the aggradation of a carbonate platform while deepwater mixed-systems prevailed in the basin. During the Oligo-Miocene, three major sedimentary pathways are expected to drive important

  12. Radiogenic heat production in sedimentary rocks of the Gulf of Mexico Basin, south Texas

    USGS Publications Warehouse

    McKenna, T.E.; Sharp, J.M.

    1998-01-01

    Radiogenic heat production within the sedimentary section of the Gulf of Mexico basin is a significant source of heat. Radiogenic heat should be included in thermal models of this basin (and perhaps other sedimentary basins). We calculate that radiogenic heat may contribute up to 26% of the overall surface heat-flow density for an area in south Texas. Based on measurements of the radioactive decay rate of ??-particles, potassium concentration, and bulk density, we calculate radiogenic heat production for Stuart City (Lower Cretaceous) limestones, Wilcox (Eocene) sandstones and mudrocks, and Frio (Oligocene) sandstones and mudrocks from south Texas. Heat production rates range from a low of 0.07 ?? 0.01 ??W/m3 in clean Stuart City limestones to 2.21 ?? 0.24??W/m3 in Frio mudrocks. Mean heat production rates for Wilcox sandstones, Frio sandstones, Wilcox mudrocks, and Frio mudrocks are 0.88, 1.19, 1.50, and 1.72 ??W/m3, respectively. In general, the mudrocks produce about 30-40% more heat than stratigraphically equivalent sandstones. Frio rocks produce about 15% more heat than Wilcox rocks per unit volume of clastic rock (sandstone/mudrock). A one-dimensional heat-conduction model indicates that this radiogenic heat source has a significant effect on subsurface temperatures. If a thermal model were calibrated to observed temperatures by optimizing basal heat-flow density and ignoring sediment heat production, the extrapolated present-day temperature of a deeply buried source rock would be overestimated.Radiogenic heat production within the sedimentary section of the Gulf of Mexico basin is a significant source of heat. Radiogenic heat should be included in thermal models of this basin (and perhaps other sedimentary basins). We calculate that radiogenic heat may contribute up to 26% of the overall surface heat-flow density for an area in south Texas. Based on measurements of the radioactive decay rate of ??-particles, potassium concentration, and bulk density, we

  13. Uncertainty quantification of overpressure buildup through inverse modeling of compaction processes in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Colombo, Ivo; Porta, Giovanni M.; Ruffo, Paolo; Guadagnini, Alberto

    2016-11-01

    This study illustrates a procedure conducive to a preliminary risk analysis of overpressure development in sedimentary basins characterized by alternating depositional events of sandstone and shale layers. The approach rests on two key elements: (1) forward modeling of fluid flow and compaction, and (2) application of a model-complexity reduction technique based on a generalized polynomial chaos expansion (gPCE). The forward model considers a one-dimensional vertical compaction processes. The gPCE model is then used in an inverse modeling context to obtain efficient model parameter estimation and uncertainty quantification. The methodology is applied to two field settings considered in previous literature works, i.e. the Venture Field (Scotian Shelf, Canada) and the Navarin Basin (Bering Sea, Alaska, USA), relying on available porosity and pressure information for model calibration. It is found that the best result is obtained when porosity and pressure data are considered jointly in the model calibration procedure. Uncertainty propagation from unknown input parameters to model outputs, such as pore pressure vertical distribution, is investigated and quantified. This modeling strategy enables one to quantify the relative importance of key phenomena governing the feedback between sediment compaction and fluid flow processes and driving the buildup of fluid overpressure in stratified sedimentary basins characterized by the presence of low-permeability layers. The results here illustrated (1) allow for diagnosis of the critical role played by the parameters of quantitative formulations linking porosity and permeability in compacted shales and (2) provide an explicit and detailed quantification of the effects of their uncertainty in field settings.

  14. Uncertainty quantification of overpressure buildup through inverse modeling of compaction processes in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Colombo, Ivo; Porta, Giovanni M.; Ruffo, Paolo; Guadagnini, Alberto

    2017-03-01

    This study illustrates a procedure conducive to a preliminary risk analysis of overpressure development in sedimentary basins characterized by alternating depositional events of sandstone and shale layers. The approach rests on two key elements: (1) forward modeling of fluid flow and compaction, and (2) application of a model-complexity reduction technique based on a generalized polynomial chaos expansion (gPCE). The forward model considers a one-dimensional vertical compaction processes. The gPCE model is then used in an inverse modeling context to obtain efficient model parameter estimation and uncertainty quantification. The methodology is applied to two field settings considered in previous literature works, i.e. the Venture Field (Scotian Shelf, Canada) and the Navarin Basin (Bering Sea, Alaska, USA), relying on available porosity and pressure information for model calibration. It is found that the best result is obtained when porosity and pressure data are considered jointly in the model calibration procedure. Uncertainty propagation from unknown input parameters to model outputs, such as pore pressure vertical distribution, is investigated and quantified. This modeling strategy enables one to quantify the relative importance of key phenomena governing the feedback between sediment compaction and fluid flow processes and driving the buildup of fluid overpressure in stratified sedimentary basins characterized by the presence of low-permeability layers. The results here illustrated (1) allow for diagnosis of the critical role played by the parameters of quantitative formulations linking porosity and permeability in compacted shales and (2) provide an explicit and detailed quantification of the effects of their uncertainty in field settings.

  15. High-resolution seismic imaging of the Sohagpur Gondwana basin, central India: Evidence for syn-sedimentary subsidence and faulting

    NASA Astrophysics Data System (ADS)

    Dhanam, K.; Kumar, P. Senthil; Mysaiah, D.; Prasad, P. Prabhakara; Seshunarayana, T.

    2013-12-01

    Gondwana sedimentary basins in the Indian Shield preserve a rich record of tectonic, sedimentary and volcanic processes that affected Gondwanaland. The Gondwana rocks were deposited in the linear rift basins that were formed during Permian-Cretaceous time, similar to their neighbours in Australia, Africa and Antarctica. In this study, we illustrate how Gondwana tectonics affected the Sohagpur Gondwana basin that occurs at the junction of the Mahanadi and Son-Narmada rift systems in the central India, through a high-resolution seismic reflection study along six profiles, covering the central part of the Sohagpur basin. The study reveals (1) ˜1000 m thick, gently dipping Barakar Formation, (2) thick coal seams at a depth of 350-550 m, and (3) NNW-SSE to NW-SE striking steeply dipping normal faults defining rift geometry. These results indicate that the Sohagpur basin contains a thick Lower Gondwana sedimentary succession with a high potential of coal resources and were affected by extensional tectonics. The rift structure in the study area is a syn- to post-sedimentary deformational structure that was formed arguably in response to tectonics that pervasively affected Gondwanaland.

  16. Large Circular Basin Flooded and then Cratered

    NASA Image and Video Library

    2000-08-05

    As NASA Mariner 10 passed by Mercury on its second encounter with the planet on Sept. 21, 1974, this picture of a large circular 350 kilometer, 220 mile diameter basin was obtained near the morning terminator.

  17. Integrated geophysical investigations of linkages between Precambrian basement and sedimentary structures in the Ucayali basin, Peru; Fort Worth basin, Texas; and Osage County, Oklahoma

    NASA Astrophysics Data System (ADS)

    Elebiju, Olubunmi Olumide

    I conducted integrated geophysical studies within the Fort Worth basin, Texas; Osage County, Oklahoma, and the Ucayali basin, Peru. My studies are directed at understanding the relationships or links between Precambrian basement structures and sedimentary structures using these three areas as case studies. Links between basement structure, hydrocarbon reservoirs, and sedimentary sequences are not a new concept. Such relationships have been documented in the Paradox, Hardeman, Anadarko, Arkoma, Ardmore and Williston basins among others. Structures such as fault zones that can influence the formation of sedimentary basins and mineral deposits are often formed by intraplate tectonism. In order to compare the relationship between the Precambrian basement structures and sedimentary structures, I analyzed series of derivative and filtered maps of aeromagnetic and gravity data, which enhance basement structures, that were integrated with seismic data and seismic attribute data that enhance structures within the sedimentary sections. Other information such as well data and geologic information etc were also integrated. This integrated workflow facilitates the comparison of the links or relationships between the two structures. The results of the Fort Worth basin are presented in Chapter 3. The results of this integrated study show that the sedimentary structures within the study area are mainly related to basement structures because these structures are aligned parallel to anomalies identified on the high-resolution aeromagnetic (HRAM) data. The northeast-southwest and northwest-southeast orientations of sedimentary features are consistently parallel with Precambrian structural fabrics that are associated with structures such as the northeast trending Ouachita orogenic belt and the northwest trending Muenster Arch, which reactivated a late Cambrian/Late Precambrian faults. The knowledge gained in this study will impact oil and gas exploration and development within the

  18. Palynostratigraphy and sedimentary facies of Middle Miocene fluvial deposits of the Amazonas Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Dino, Rodolfo; Soares, Emílio Alberto Amaral; Antonioli, Luzia; Riccomini, Claudio; Nogueira, Afonso César Rodrigues

    2012-03-01

    Palynostratigraphic and sedimentary facies analyses were made on sedimentary deposits from the left bank of the Solimões River, southwest of Manaus, State of Amazonas, Brazil. These provided the age-dating and subdivision of a post-Cretaceous stratigraphic succession in the Amazonas Basin. The Novo Remanso Formation is subdivided into upper and lower units, and delineated by discontinuous surfaces at its top and bottom. The formation consists primarily of sandstones and minor mudstones and conglomerates, reflecting fluvial channel, point bar and floodplain facies of a fluvial meandering paleosystem. Fairly well-preserved palynoflora was recovered from four palynologically productive samples collected in a local irregular concentration of gray clay deposits, rich in organic material and fossilized wood, at the top of the Novo Remanso Formation upper unit. The palynoflora is dominated by terrestrial spores and pollen grains, and is characterized by abundant angiosperm pollen grains ( Tricolpites, Grimsdalea, Perisyncolporites, Tricolporites and Malvacearumpollis). Trilete spores are almost as abundant as the angiosperm pollen, and are represented mainly by the genera Deltoidospora, Verrutriletes, and Hamulatisporis. Gymnosperm pollen is scarce. The presence of the index species Grimsdalea magnaclavata Germeraad et al. (1968) indicates that these deposits belong to the Middle Miocene homonymous palynozone (Lorente, 1986; Hoorn, 1993; Jaramillo et al., 2011). Sedimentological characteristics (poorly sorted, angular to sub-angular, fine to very-coarse quartz sands facies) are typical of the Novo Remanso Formation upper part. These are associated with a paleoflow to the NE-E and SE-E, and with an entirely lowland-derived palinofloristic content with no Andean ferns and gymnosperms representatives. All together, this suggests a cratonic origin for this Middle Miocene fluvial paleosystem, which was probably born in the Purus Arch eastern flank and areas surrounding the

  19. Tectonics and petroleum potential of sedimentary basins in the Bering, Okhotsk, Japan seas, and island arcs

    SciTech Connect

    Levin, L.E. )

    1993-09-01

    In this vast region located in the northwestern part of the Pacific rim, basins of two main genetic types possess petroleum potential. These two types are represented by basins of the recent active margin and basins of the transitional zone between analogs of the passive margin and the recent active margin. For basins of the active margin, the mean density of potential resources is estimated at 5000 MT/km[sup 2] or more. The total area of these basins is 324,000 km[sup 2] among which 120,000 km[sup 2] are in the Russian sector. Ultimate resources of hydrocarbons are estimated at 1.62 billing MT of oil equivalent. Basins of the zone, transitional from analogs of the passive margin to the recent active margin, are characterized by a number of factors favorable for petroleum occurrence. One of the important factors is the presence of rift trough and foredeeps that are potential sites for zones of oil and gas accumulation. The age of the rifts varies from the late Cretaceous through the Oligocene-Miocene in the Olyutorsky and Litke basins, to the Neogene in the Okhotsk Sea and Tatar-Japan basins. Only a small area of the rifts has been proven to contain zones of oil and gas accumulation. Based on the structural characteristics, the rifts are subdivided into oil-gas bearing, potentially oil-gas bearing, and nonprospective for hydrocarbon exploration. Potential hydrocarbon resources of basins of this type are estimated to be not less than 15.12 billion MT of oil equivalent including 9.2 billion MT in the Russian sector. New large zones of oil and gas accumulation are expected to be found both on the shallow shelf and in some deep-water basins such as in the Aleutian and Kuril basins.

  20. Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins

    NASA Astrophysics Data System (ADS)

    Bhatia, Mukul R.; Crook, Keith A. W.

    1986-02-01

    The graywackes of Paleozoic turbidite sequences of eastern Australia show a large variation in their trace element characteristics, which reflect distinct provenance types and tectonic settings for various suites. The tectonic settings recognised are oceanic island arc, continental island arc, active continental margin, and passive margins. Immobile trace elements, e.g. La, Ce, Nd, Th, Zr, Nb, Y, Sc and Co are very useful in tectonic setting discrimination. In general, there is a systematic increase in light rare earth elements (La, Ce, Nd), Th, Nb and the Ba/Sr, Rb/Sr, La/Y and Ni/Co ratios and a decrease in V, Sc and the Ba/Rb, K/Th and K/U ratios in graywackes from oceanic island arc to continental island arc to active continental margin to passive margin settings. On the basis of graywacke geochemistry, the optimum discrimination of the tectonic settings of sedimentary basins is achieved by La-Th, La-Th-Sc, Ti/Zr-La/Sc, La/Y-Sc/Cr, Th-Sc-Zr/10 and Th-Co-Zr/10 plots. The analysed oceanic island arc graywackes are characterised by extremely low abundances of La, Th, U, Zr, Nb; low Th/U and high La/Sc, La/Th, Ti/Zr, Zr/Th ratios. The studied graywackes of the continental island arc type setting are characterised by increased abundances of La, Th, U, Zr and Nb, and can be identified by the La-Th-Sc and La/Sc versus Ti/Zr plots. Active continental margin and passive margin graywackes are discriminated by the Th-Sc-Zr/10 and Th-Co-Zr/10 plots and associated parameters (e.g. Th/Zr, Th/Sc). The most important characteristic of the analysed passive margin type graywackes is the increased abundance of Zr, high Zr/Th and lower Ba, Rb, Sr and Ti/Zr ratio compared to the active continental margin graywackes.

  1. Potential leakage between aquifers in a deeply anthropized coastal sedimentary basin (Recife, Brazil): Strontium isotope constraints

    NASA Astrophysics Data System (ADS)

    Petelet-Giraud, Emmanuelle; Cary, Lise; Hirata, Ricardo; Martins, Veridiana; Bertrand, Guillaume; Montenegro, Suzana; Pauwels, Helene; Kloppmann, Wolfram; Aquilina, Luc

    2013-04-01

    Due to an increasing demographic pressure, the Metropolitan Region of Recife (RMR) went through remarkable changes of water and land uses over the last decades. These evolutions gave rise to numerous environmental consequences, such as a dramatic decline of the piezometric levels, groundwater salinization and contamination. This degradation of natural resources is linked to the increase of water demand, punctually amplified by drought periods which induced the construction of thousands of private wells. Recife was built on the estuarine area of the Capibaribe River and other small rivers. The Recife coastal plain is located in the geographic limits of the sedimentary basins of Cabo and Pernambuco-Paraíba which consist out of fluvial and marine geologic formations. It is composed of three main aquifers: the two semi-confined Cabo and Beberibe aquifers, both underlining the superficial Boa Viagem unconfined aquifer, which is the most directly exposed to contamination, since it is connected to mangroves, rivers, estuaries and highly urbanized areas. The Boa Viagem aquifer is made of marine terraces of sand, silt and clay has an average thickness of 40 m. The Cabo aquifer occurs in the south of Recife and comprises sandstones, siltstones and mudstones, with an average thickness of 90 m. The Beberibe aquifer occurs in the north and central area of Recife with an average thickness of 100 m of sandstones with intercalations of mudstone; it is the most important one, with the highest amount of good quality water. Both the Beberibe and Cabo aquifers contain large clay levels. The hydraulic connections between the three aquifers are not well known but isotopic studies have shown that the recharge processes are similar, suggesting that exchanges may occur and may be modified or amplified by overexploitation especially between the Cabo and Boa Viagem aquifers. Two other aquifers can be found west of the city: the Barreiras aquifer, characterized by alternating well stratified

  2. LIP volcanism and paleo-environmental crises - impact of magma emplacement sequence on thermogenic degassing rates from the Karoo sedimentary basin

    NASA Astrophysics Data System (ADS)

    Galerne, Christophe; Hasenclever, Jörg

    2017-04-01

    Volcanism in organic-rich sedimentary basins leading to thermogenic greenhouse gas generation has been documented as a strong forcing factor of past mass extinctions. However, quantitative studies fail to provide degassing rate estimates that would allow a direct comparison with anthropogenic warming. We are investigating different sill-emplacement sequences of a Large Igneous Province (LIP) plumbing system to identify their potential variable impact in terms of thermogenic degassing rates and cumulative amount of gas released at the basin top. We use a 2D finite element model that solves for hydrothermal fluid flow and thermal evolution around several cooling intrusions. Igneous sills are represented by horizontally dominated thermal anomalies that are sequentially placed within the sedimentary basin. We test different end-member scenarios of emplacement like bottom-to-top, top-to-bottom, and arbitrary emplacement order. Degassing pulses monitored during the simulations are recorded and compared for various end-member scenarios. The LIP emplaced in the Karoo Basin (South Africa, 183 Ma) is considered as a case study. We use basin lithostratigraphic properties (e.g. Total Organic Carbon content, sill to sediment proportion and structural data) to discuss results of our end-member models. This research potentially holds the key to demonstrate whether or not anthropogenic warming is in a comparable range to a documented paleo-environmental crisis and mass extinction triggered by degassing related volcanism.

  3. Sediment storage quantification and postglacial evolution of an inner-alpine sedimentary basin (Gradenmoos, Schober Mountains, Austria)

    NASA Astrophysics Data System (ADS)

    Götz, J.; Buckel, J.; Otto, J. C.; Schrott, L.

    2012-04-01

    Knickpoints in longitudinal valley profiles of alpine headwater catchments can be frequently assigned to the lithological and tectonical setting, to damming effects through large (rockfall) deposits, or to the impact of Pleistocene glaciations causing overdeepened basins. As a consequence various sedimentary sinks developed, which frequently interrupt sediment flux in alpine drainage basins. Today these locations may represent landscape archives documenting a sedimentary history of great value for the understanding of alpine landscape evolution. The glacially overdeepened Gradenmoos basin at 1920 m a.s.l. (an alpine lake mire with adjacent floodplain deposits and surrounding slope storage landforms; approx. 4.1 km2) is the most pronounced sink in the studied Gradenbach catchment (32.5 km2). The basin is completely filled up with sediments delivered by mainly fluvial processes, debris flows, and rock falls, it is assumed to be deglaciated since Egesen times and it is expected to archive a continuous stratigraphy of postglacial sedimentation. As the analysis of denudation-accumulation-systems is generally based on back-calculation of stored sediment volumes to a specific sediment delivering area, most reliable results will be consequently obtained (1) if sediment output of the system can be neglected for the investigated period of time, (2) if - due to spatial scale - sediment storage can be assessed quantitatively with a high level of accuracy, and (3) if the sediment contributing area can be clearly delimited. All three aspects are considered to be fulfilled to a high degree within the Gradenmoos basin. Sediment storage is quantified using geophysical methods, core drillings and GIS modelling whereas postglacial reconstruction is based on radiocarbon dating and palynological analyses. Subject to variable subsurface conditions, different geophysical methods were applied to detect bedrock depth. Electrical resistivity surveying (2D/3D) was used most extensively as it

  4. Compositions and greenhouse gas emission factors of flared and vented gas in the Western Canadian Sedimentary Basin.

    PubMed

    Johnson, Matthew R; Coderre, Adam R

    2012-09-01

    A significant obstacle in evaluating mitigation strategies for flaring and venting in the upstream oil and gas industry is the lack of publicly available data on the chemical composition of the gas. This information is required to determine the economic value of the gas, infrastructure and processing requirements, and potential emissions or emissions credits, all of which have significant impact on the economics of such strategies. This paper describes a method for estimating the composition of solution gas being flared and vented at individual facilities, and presents results derived for Alberta, Canada, which sits at the heart of the Western Canadian Sedimentary Basin. Using large amounts of raw data obtained through the Alberta Energy Resources Conservation Board, a relational database was created and specialized queries were developed to link production stream data, raw gas samples, and geography to create production-linked gas composition profiles for approximately half of the currently active facilities. These were used to create composition maps for the entire region, to which the remaining facilities with unknown compositions were geographically linked. The derived data were used to compute a range of solution gas composition profiles and greenhouse gas emission factors, providing new insight into flaring and venting in the region and enabling informed analysis of future management and mitigation strategies. Accurate and transparent determination of environmental impacts of flaring and venting of gas associated with oil production, and potential benefits of mitigation, is severely hampered by the lack of publicly available gas composition data. In jurisdictions within the Western Canadian Sedimentary Basin, frameworks exist for regulating and trading carbon offset credits but current potential for mitigation is limited by a lack of standardized methods for calculating CO2 equivalent emissions. The composition and emission factor data derived in this paper

  5. Sedimentary facies in an extensional and deep-lacustrine depositional system: the Pliocene Tiberino Basin, Central Italy

    NASA Astrophysics Data System (ADS)

    Basilici, Giorgio

    1997-03-01

    The Tiberino Basin was formed during Plio-Pleistocene extensional tectonic activity in Central Italy. The Pliocene sediments that fill this structure consist predominately of fine-grained clastic lithofacies deposited in a lacustrine system; four facies associations have been distinguished. Facies association A was deposited in a deep-offshore lacustrine environment and consists of massive, laminated, bluish-gray marly clays that lack benthonic fauna but have preserved organic matter (leaves, wood). This facies association is the main lacustrine deposit, whereas the other three represent marginal facies. Facies association B is interpreted as a delta system deposit; it has Gilbert-type sandy gravel bodies with foresets up to 50 m high and prodelta bodies consisting of laminated to massive marly clays that alternate with sandy and gravelly mud strata. Association C corresponds to a coastal environment, where two sub-environments are recognized: (1) a wave-dominated coastline characterized by interbedded muddy and sandy strata with sedimentary structures attributed to hummocky cross-stratification; and (2) clayey silts and lignites interpreted as a coastal wetland; a spectacular fossil forest is preserved in situ within this unit. Association D, formed on the distal part of a muddy alluvial fan, consists of sheet-flood clayey sandy silts, that alternate with incipient paleosols; rare, ribbon-channel fills are also present. Paleoenvironmental reconstruction indicates that the Tiberino Basin was occupied by a narrow, deep meromictic lake during the Pliocene. The size, shape, depth and sub-environment distribution of this lake were controlled by tectonic phenomena, such as the high subsidence rate, which caused the lake to be large and deep. Only in the few coastal areas that had high sedimentary input were wetland or alluvial fan deposits formed.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  7. Hydraulic characteristics of the Maastrichtian sedimentary rocks of the southeastern Bida Basin, central Nigeria

    NASA Astrophysics Data System (ADS)

    Vrbka, Petr; Ojo, Olusola Johnson; Gebhardt, Holler

    1999-12-01

    A set of outcrop samples from the Lokoja and Patti Formations of the southern Bida Basin (Nigeria) was examined for grain size distribution, sedimentary and hydraulic characteristics. Most of the samples are well-sorted with an uniformity coefficient (U) ranging between 1.3 and 6.3. The mean effective grain diameter (d 10) is in the order of 0.11 mm, the mean value of d 90 was determined as 0.66 mm (both geometric mean) and the median grain size (d 50) as 0.23 mm. Based on these values, the sedimentary sequence can be described as 'fine to medium sized sand', having minor amounts of either silt, or coarse sand and some gravel. The total porosity of the samples was determined by laboratory methods to be in the range of 9-29%. The hydraulic conductivity (K) was determined according to Hazen.and Beyer, and by Shepherd's formula, the last resulting in a geometric mean of 3.3 m d -1 or 3.3 darcy. The results are used to estimate local groundwater potential. The entire pore space (potential groundwater reservoir) for the area under study is estimated to be in the order of 290-430 km 3. Because of higher hydraulic conductivities, it is recommended that the Lokoja Formation is concentrated on as a target for groundwater exploration.

  8. A sedimentary paleomagnetic record of the upper Jaramillo transition from the Lantian Basin in China

    NASA Astrophysics Data System (ADS)

    Wu, Yi; Ouyang, Tingping; Qiu, Shifan; Rao, Zhiguo; Zhu, Zhaoyu

    2015-10-01

    The termination of the Jaramillo (normal to reverse) subchron is a key chronostratigraphic marker for dating global Pleistocene sedimentary sequences. However, the stratigraphic position of the geomagnetic polarity reversal varies greatly across the Chinese Loess Plateau (CLP), from near the bottom of paleosol unit S9 to the middle-upper part of S10. Here, we present paleomagnetic and rock magnetic results from high-resolution sampling of the Yushan loess section of the Lantian Basin located within the southern CLP. Our combined analyses determine that the polarity reversal is located in the middle-lower part of the paleosol unit S10. This stratigraphic position is lower than most of other studies conducted throughout the CLP. We attribute the difference in the location of the reversal to a deeper lock-in depth of remanence acquisition, which may have occurred from postdepositional processes under favorable hydrothermal conditions along the southern margin of CLP. It is important to note that age determinations through magnetic stratigraphy on sedimentary sections, particularly in discontinuous and/or imperfect sequences, should be treated with caution; there are significant differences with respect to the location of the polarity reversal throughout the CLP.

  9. South China connected to north India in Gondwana: sedimentary basin and detrital provenance analyses

    NASA Astrophysics Data System (ADS)

    Yao, W.; Li, Z. X.; Li, W. X.; Li, X. H.; Yang, J. H.

    2015-12-01

    The paleoposition of South China during the Ediacaran-Silurian is important for understanding the assembly of Gondwana. We report here the tectonostratigraphic evolution of the Ediacaran-Silurian Nanhua foreland basin in South China, and discuss South China's connection with Gondwana and potential tectonic triggers for both the Wuyi-Yunkai orogeny in South China and the Bhimphedian orogeny in north India. The Nanhua basin was involved in a three-stage evolution, which are: Stage 1 (the Ediacaran-Cambrian) recording the start of tectonic subsidence with turbiditic marine clastic deposition, fed by exotic orogens outboard South China; Stage 2 (the Ordovician to earliest-Silurian) featured by migrating depocentres with dominant shallow marine to deltaic clastic deposition, fed by the local Wuyi-Yunkai orogen; and Stage 3 (the Silurian) showing the arrival of depocentre in the Yangtze Block during the waning stage of the Wuyi-Yunkai orogeny with deltaic deposition in the remanent foreland basin. Detrital zircon analyses of the Ediacaran-Silurian sandstones across the Nanhua basin reveal a prominent age population of 1100-900 Ma (with a peak age at ~980 Ma) and moderate populations of Archean-Paleozoic ages, grossly matching that of crystalline and sedimentary rocks in northern India. Zircon isotopes of the Stage 1 samples suggest three Precambrian episodes of juvenile crustal growth at 3.0 Ga, 2.5 Ga and 1.0 Ga, and a major crustal reworking at 580-500 Ma for the source areas, which are constraint to be northwestern India and its surrounding orogens. Together with other evidence, we propose that South China likely collided with northwestern India during the Gondwana assembly, generated the Bhimphedian orogeny in north India and formed two foreland basins on both the north India and South China sides. Far-field stress of the collision triggered the Ordovician-Silurian Wuyi-Yunkai orogeny in South China. The Stage 2-3 samples in the Nanhua basin of South China were shed

  10. Estimation of Sedimentary Thickness in Kachchh Basin, Gujarat Using SP Converted Phase

    NASA Astrophysics Data System (ADS)

    Chopra, Sumer; Rao, K. M.; Rastogi, B. K.

    2010-10-01

    An inexpensive method using natural earthquake data is utilized for determining the sedimentary thickness in Kachchh. The Institute of Seismological Research (ISR) is operating a network of broadband seismographs and strong motion accelerographs in Gujarat. We used data from 13 broadband seismographs and two strong motion accelerographs in the study. The stations are within 5 to 80 km from the epicenters. In this study the S-to-P converted phase, SP, is used. This phase is generated due to large impedance contrast between sediments and basement. This phase is clear in the vertical component. The difference in the travel times of S and SP phases and velocities of P and S waves is used for determining the sedimentary layer thickness. The thickness of sediments beneath each of these 15 stations was determined covering an area of 23,500 sq km.

  11. Distributed model of hydrological and sediment transport processes in large river basins in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Zuliziana, S.; Tanuma, K.; Yoshimura, C.; Saavedra, O. C.

    2015-07-01

    Soil erosion and sediment transport have been modeled at several spatial and temporal scales, yet few models have been reported for large river basins (e.g., drainage areas > 100 000 km2). In this study, we propose a process-based distributed model for assessment of sediment transport at a large basin scale. A distributed hydrological model was coupled with a process-based distributed sediment transport model describing soil erosion and sedimentary processes at hillslope units and channels. The model was tested on two large river basins: the Chao Phraya River Basin (drainage area: 160 000 km2) and the Mekong River Basin (795 000 km2). The simulation over 10 years showed good agreement with the observed suspended sediment load in both basins. The average Nash-Sutcliffe efficiency (NSE) and average correlation coefficient (r) between the simulated and observed suspended sediment loads were 0.62 and 0.61, respectively, in the Chao Phraya River Basin except the lowland section. In the Mekong River Basin, the overall average NSE and r were 0.60 and 0.78, respectively. Sensitivity analysis indicated that suspended sediment load is sensitive to detachability by raindrop (k) in the Chao Phraya River Basin and to soil detachability over land (Kf) in the Mekong River Basin. Overall, the results suggest that the present model can be used to understand and simulate erosion and sediment transport in large river basins.

  12. Origin and Evolution of Sedimentary Basins and Their Energy and Mineral Resources

    NASA Astrophysics Data System (ADS)

    Price, Raymond A.

    The International Lithosphere Program was launched in 1981 as a ten-year project of interdisciplinary research in the solid earth sciences. It is a natural outgrowth of the Geodynamics Program of the 1970's, and of its predecessor, the Upper Mantle Project. The Program — "Dynamics and Evolution of the Lithosphere: The Hazards"—is concerned primarily with the current state, origin and development of the lithosphere, with special attention to the continents and their margins. One special goal of the program is the strengthening of interactions between basic research and the applications of geology, geophysics, geochemistry and geodesy to mineral and energy resource exploration and development, to the mitigation of geological hazards, and to protection of the environment; another special goal is the strengthening of the earth sciences and their effective application in developing countries. The origin and evolution of sedimentary basins is an obvious focus of the International Lithosphere Program because it is fundamentally a problem in the dynamics and evolution of the lithosphere, and moreover, it provides special opportunities for strengthening the interactions between basic research and the applications of geology, geophysics, geochemistry and geodesy to mineral and energy exploration and development. Accordingly, at both the XXVIIth International Geological Congress in Moscow, in 1984, and at the XIXth General Assembly of the International Union of Geodesy and Geophysics in Vancouver, in 1987, the International Lithosphere Program convened special symposia on the subject of the origin and evolution of sedimentary basins and their mineral and energy resources. This special volume presents some of the principal results of those symposia.

  13. Magnetostratigraphy of the middle-upper Jurassic sedimentary sequences at Yanshiping, Qiangtang Basin, China

    NASA Astrophysics Data System (ADS)

    Song, Chunhui; Zeng, Yongyao; Yan, Maodu; Wu, Song; Fang, Xiaomin; Bao, Jing; Zan, Jinbo; Liu, Xifang

    2016-09-01

    A series of important geological events occurred in the Tibetan Plateau area during the Jurassic, such as the collision of the Lhasa and Qiangtang Terranes, the closure of the Meso-Tethyan Ocean, the opening of the Neo-Tethyan Ocean and the cessation of the mega-monsoon. The ˜3000 m thick Jurassic sedimentary sequence in the Qiangtang Basin on the central Tibetan Plateau, which is called the Yanshiping (YSP) Group, recorded these geological events. However, the chronology of the sequence is surprisingly poorly constrained. Here, we perform a detailed palaeomagnetic analysis on the ˜1060 m thick middle and upper portions of the YSP Group (the Xiali and Suowa Formations) in the YSP section of the eastern Qiangtang Basin. Three bivalve zones at stratigraphic intervals of ˜40-140, 640-800 and 940-1040 m are identified, which yield a Bathonian-Callovian age for the Lower Xiali Fm., a Callovian-Oxfordian age for the Lower Suowa Fm. and an Oxfordian-Kimmeridgian age for the Upper Suowa Fm. A total of 544 oriented palaeomagnetic samples were collected from the section. By combining thermal and alternating field demagnetizations, clear characteristic remanent magnetization (ChRM) directions are isolated for most of the samples. The robust ChRM directions pass fold and reversals tests, which support the primary nature of the ChRMs and yield a palaeopole at 76.8°N/297.2°E (dp = 2.2°, dm = 3.7°). A total of 27 normal and 26 reversed polarity zones were successfully recorded in the section. Combined with fossil age constraints, results suggest that the section is plausibly composed of a Callovian-Early Kimmeridgian age sedimentary sequence.

  14. Sedimentology and Sedimentary Dynamics of the Desmoinesian Cherokee Group, Deep Anadarko Basin, Texas Panhandle

    NASA Astrophysics Data System (ADS)

    Hu, N.; Loucks, R.; Frebourg, G.

    2015-12-01

    Understanding the spatial variability of deep-water facies is critical to deep-water research because of its revealing information about the relationship between desity flow processes and their resultant sedimentary sequences. The Cherokee Group in the Anadarko Basin, northeastern Texas Panhandle, provides an opportunity to investigate an icehouse-greenhouse Pennsylvanian hybrid system that well demonstrates the intricacies of vertical and lateral facies relationships in an unconfined fan-delta fed deep-water slope to basinal setting. The stratigraphic section ranges in thickness from 150 to 460 m. The cyclic sedimentation and foreland basin tectonics resulted in a complex stratal architecture that was sourced by multiple areas of sediment input. This investigation consists of wireline-log and core data. Five-thousand wireline logs were correlated in an area of over 9500 sq km to map out six depositional sequences that are separated by major flooding events. These events are correlative over the whole area of study. Six cores, that sample nearly the complete section, were described for lithofacies. Lithofacies are recognized based on depositional features and mineralogy:(1) Subarkose, (2) Lithicarkoses, (3) Sandy siliciclastic conglomerate, (4) Muddy calcareous conglomerate, (5) Crinoidal packstone, (6) Oodic grainstone, (7)Pelodic grainstone, (8) Ripple laminated mudrock, (9) faint laminated mudrock. The integration of isopachs of depositional sequences with the lithofacies has allowed the delineation of the spatial and temporal evolution of the slope to basin-floor system. Thin-to-thick bedded turbidites, hyperconcentrated density flow deposits (slurry beds), and debris and mud flow deposits were observed and can be used to better predicte lithofacies distributions in areas that have less data control. These mixed siliciclastic and carbonate deposits can be carrier beds for the hydrocarbons generated from the enclosing organic-rich (TOC ranges from 0.55 to 6.77wt

  15. Distinguishing between water column and sedimentary denitrification in the Santa Barbara Basin using the stable isotopes of nitrate

    NASA Astrophysics Data System (ADS)

    Sigman, D. M.; Robinson, R.; Knapp, A. N.; van Geen, A.; McCorkle, D. C.; Brandes, J. A.; Thunell, R. C.

    2003-05-01

    Below its sill depth, the Santa Barbara Basin (SBB) is commonly suboxic ([O2] ˜ 3 μM), with only brief periods of ventilation. Associated with development of suboxia, the concentration of nitrate decreases with depth into the basin without an associated decrease in phosphate, indicating that a substantial fraction of the nitrate supplied to the basin is removed by denitrification. Coincident with the decrease in nitrate concentration across the "redoxcline" (the interface between oxic and suboxic waters) within the SBB, there is an increase in the 15N/14N of that nitrate, as would be anticipated from the isotopic fractionation associated with denitrification. However, the increase in 15N/14N of nitrate is much smaller than occurs in the open eastern tropical North Pacific (ETNP) for a comparable amount of nitrate loss. Both the concentrations of N species within the basin and measurements of nitrate 18O/16O suggest that the lower-than-expected 15N enrichment in the suboxic SBB involves denitrification, rather than being due to some unknown source of low-15N/14N N to the deep SBB. Calculations with a range of models of nitrate supply and consumption indicate that the degree of nitrate consumption in the basin is too small for differences in water circulation to explain the isotopic differences between the Santa Barbara Basin and the open ETNP. Previous studies indicate that the isotope effect of sedimentary denitrification is negligible due to nitrate diffusion in sediment pore waters. Thus we infer that the small magnitude of the isotopic enrichment of SBB water column nitrate is due to the importance of sedimentary denitrification within the basin. Assuming that water column and sedimentary denitrification have isotope effects of 25 and 1.5 per mil, respectively, our results suggest that sedimentary denitrification accounts for more than 75% of the nitrate loss within the suboxic SBB.

  16. A study of uranium favorability of Cenozoic sedimentary rocks, Basin and Range Province, Arizona: Part I, General geology and chronology of pre-late Miocene Cenozoic sedimentary rocks

    USGS Publications Warehouse

    Scarborough, Robert Bryan; Wilt, Jan Carol

    1979-01-01

    This study focuses attention on Cenozoic sedimentary rocks in the Basin and Range Province of Arizona. The known occurrences of uranium and anomalous radioactivity in these rocks are associated with sediments that accumulated in a low energy environment characterized by fine-grained clastics, including important tuffaceous materials, and carbonate rocks. Most uranium occurrences, in these rocks appear to be stratabound. Emphasis was placed on those sedimentary materials that pre-date the late Cenozoic Basin and Range disturbance. They are deformed and crop out on pedimented range blocks and along the province interface with the Transition Zone. Three tentative age groups are recognized: Group I - Oligocene, pre-22 m.y., Group II - early Miocene - 22 m.y. - 16 m.y., and Group III - middle Miocene - 16 m.y. to 13--10 m.y. Regionally, these three groups contain both coarse to fine-grained red clastics and low energy lighter colored 'lacustrine' phases. Each of the three groups has been the object of uranium exploration. Group II, the early Miocene strata, embraces the Anderson Mine - Artillery region host rocks and also the New River - Cave Creek early Miocene beds-along the boundary with the Transition Zone. These three groups of rocks have been tectonically deformed to the extent that original basins of deposition cannot yet be reconstructed. However, they were considerably more extensive in size than the late Cenozoic basins the origin of which deformed the former. Group II rocks are judged to be of prime interest because of: (1) the development and preservation of organic matter in varying lithologies, (2) apparent contemporaneity with silicic volcanic centers, (3) influence of Precambrian crystalline rocks, and (4) relative outcrop continuity near the stable Transition Zone. The Transition Zone, especially along its boundary with the Basin and Range Province, needs additional geologic investigation, especially as regards the depositional continuity of Group II

  17. Norian-Rhaetian sedimentary evolution of the Slovenian Basin (eastern Southern Alps)

    NASA Astrophysics Data System (ADS)

    Gale, L.; Šmuc, A.; Kolar-Jurkovšek, T.; Skaberne, D.; Celarc, B.; Čar, J.; Rožič, B.

    2012-04-01

    The Slovenian Basin represents a Mesozoic deep water sedimentary environment, during the Triassic situated on the southern passive continental margin of the Neotethys (Meliata) Ocean (cf. Schmid et al., 2008). The Norian-Rhaetian sedimentary evolution of the Slovenian Basin is reconstructed on the basis of five sections located in different parts of the Tolmin Nappe (Eastern Southern Alps, western Slovenia). The correlation of sections is based on conodont data and facies analysis. The Norian-Rhaetian interval is in the basin represented by the "Bača dolomite" (bedded dolostone with chert) and the Slatnik Formation (hemipelagic and allodapic limestones), while the bordering reef-rimmed carbonate platforms in inner areas record peritidal deposition (Main Dolomite, Dachstein Limestone). The transition from claystone and marly limestone dominated "Amphiclina beds" to the bedded "Bača dolomite" took place at the Carnian-Norian boundary. The change in facies can be attributed to the eustatic rise of sea-level and the subsequent retreat of terrigenous input. Intensive basin-wide slumping took place during the Early Norian and marks a short period of tectonic activity. Slump breccias are followed by bedded dolostones. An increase in terrigenous input in pyrite-enriched thin-bedded dolostones indicates a relative sea-level fall (cf. Haas, 2002) at the Early-Middle Norian boundary. The Middle-Late Norian sedimentation is dominated by bedded dolostones. The microfacies analysis of scarce non-dolomitized horizons indicates hemipelagic deposition and sedimentation from distal turbidites, with material derived from adjacent platform. An interval of slump breccias suggests that another tectonic pulse took place during the Middle Norian. The Late Norian in the northern part of the Tolmin Nappe already belongs to the Slatnik Formation, which spans the rest of the Triassic, while in other parts of the Basin the "Bača dolomite" continues up to the Triassic-Jurassic boundary. The

  18. Fluid migration in sedimentary basins - a case study from the Central European Basin

    NASA Astrophysics Data System (ADS)

    Duschl, Florian; van den Kerkhof, Alfons; Leiss, Bernd; Sosa, Graciela; Wiegand, Bettina; Vollbrecht, Axel; Sauter, Martin

    2014-05-01

    Core samples from the cap rock of an Upper Permian dolomitic limestone from the Zechstein formation (Stassfurt carbonate sequence, Ca2) in the Central European Basin were studied for a better understanding of the tectonic control on fluid migration during the burial and uplift of CO2-rich gas reservoirs. Petrographical investigations were carried out by means of optical transmission and cathodoluminescence microscopy. A heating-freezing stage was applied for fluid inclusion analysis; gas compositions were measured by Laser-Raman spectroscopy. The study focuses on the quantification of paleo pressures, temperatures and compositions of diagenetic fluids trapped as inclusions in dolomite, anhydrite, calcite, and fluorite, as well as in postdiagenetic fluorite in mineralized fractures. Limestone matrix mainly consists of early diagenetic, euhedral dolomite with few hydrocarbon-bearing inclusions. Offset veins originating from fine-grained inclusion-free anhydrite nodules consist of coarse-grained recrystallized anhydrite containing primary aqueous CaCl2-rich inclusions. Late calcite cement fills remnant pores between the dolomite rhombs and contains H2O-NaCl-CaCl2 fluid inclusions. Subsequently, the dolomitic limestones were affected by pressure solution due to burial, followed by basin inversion (uplift) starting in Upper Cretaceous. Pressure solution generated carbonate rich fluids, which resulted in dolomite and calcite veinlets. Simultaneously, a first clearly zoned and brown coloured generation of fluorite (I) accumulated in nodules together with sulfides and organic matter. This fluorite (I) contains mostly H2O-NaCl-CaCl2 fluid inclusions with relatively high salinity (17.8 wt% NaCl, 8.9 wt% CaCl2). Colourless fluorite (II) is the latest observable (post-) diagenetic mineral phase filling veinlets in dolomitic limestone that crosscut pressure solution features. Fluorite (II) replaces fluorite (I) within the nodules as well. Carbonic inclusions together with CH4

  19. Analysis for preliminary evaluation of discrete fracture flow and large-scale permeability in sedimentary rocks

    SciTech Connect

    Kanehiro, B.Y.; Lai, C.H.; Stow, S.H.

    1987-05-01

    Conceptual models for sedimentary rock settings that could be used in future evaluation and suitability studies are being examined through the DOE Repository Technology Program. One area of concern for the hydrologic aspects of these models is discrete fracture flow analysis as related to the estimation of the size of the representative elementary volume, evaluation of the appropriateness of continuum assumptions and estimation of the large-scale permeabilities of sedimentary rocks. A basis for preliminary analysis of flow in fracture systems of the types that might be expected to occur in low permeability sedimentary rocks is presented. The approach used involves numerical modeling of discrete fracture flow for the configuration of a large-scale hydrologic field test directed at estimation of the size of the representative elementary volume and large-scale permeability. Analysis of fracture data on the basis of this configuration is expected to provide a preliminary indication of the scale at which continuum assumptions can be made.

  20. Large slope failures in the La Paz basin, Bolivian Andes

    NASA Astrophysics Data System (ADS)

    Roberts, N. J.; Hermanns, R. L.; Rabus, B.; Guzmán, M. A.; Minaya, E.; Clague, J. J.

    2014-12-01

    The La Paz basin in the eastern Bolivian Andes has been a hotspot for large-scale, deep-seated gravitational slope deformation during the Holocene. In less than 2 Ma, a network of steep-sided valleys up to 800 m deep formed in sediments of the Altiplano Plateau and underlying basement rocks. We characterize the distribution, extent, mechanisms, and modern activity of large-scale failures within this landscape using optical image interpretation, existing geologic maps, synthetic RADAR interferometry (InSAR), and field investigation. Deposits of nearly 20 landslides larger than 100 Mm3 occur within the basin. Most failures have occurred in weakly lithified Late Miocene to Pliocene sedimentary rocks and include earth flows, translational and rotational landslides, and plug flows. Failures in underlying tectonized Paleozoic sedimentary rocks include bedding-parallel rockslides. The largest failure is the 3 km3 Achcocalla earth flow (ca. 11 ka BP), which ran out ~20 km. Other dated events span the period from the early Holocene to nearly the Colonial historic period. InSAR results show that many large slope failures, including the Achocalla earth flow, are currently moving at rates of a few centimeters to a few decimeters per year. Rapid deposition, shallow burial, and rapid incision of the basin fills produced steep slopes in weak geologic materials that, coupled with groundwater discharge from the valley walls, are the primary controls on instability. In contrast, the Altiplano surface has changed little in 2 Ma and the adjacent slopes of the Cordilleran Real, although steep, are relatively stable. Of the over 100 landslides that have occurred in the city of La Paz since the early twentieth century, most are at the margins of large, deep-seated prehistoric failures, and two of the most damaging historic landslides (Hanko-Hanko, 1582; Pampahasi, 2011) were large-scale reactivations of previously failed slopes. Improved understanding of large, deep-seated landslides in

  1. Engineering Sedimentary Geothermal Resources for Large-Scale Dispatchable Renewable Electricity

    NASA Astrophysics Data System (ADS)

    Bielicki, Jeffrey; Buscheck, Thomas; Chen, Mingjie; Sun, Yunwei; Hao, Yue; Saar, Martin; Randolph, Jimmy

    2014-05-01

    Mitigating climate change requires substantial penetration of renewable energy and economically viable options for CO2 capture and storage (CCS). We present an approach using CO2 and N2 in sedimentary basin geothermal resources that (1) generates baseload and dispatchable power, (2) efficiently stores large amounts of energy, and (3) enables seasonal storage of solar energy, all which (5) increase the value of CO2 and render CCS commercially viable. Unlike the variability of solar and wind resources, geothermal heat is a constant source of renewable energy. Using CO2 as a supplemental geothermal working fluid, in addition to brine, reduces the parasitic load necessary to recirculate fluids. Adding N2 is beneficial because it is cheaper, will not react with materials and subsurface formations, and enables bulk energy storage. The high coefficients of thermal expansion of CO2 and N2 (a) augment reservoir pressure, (b) generate artesian flow at the production wells, and (c) produce self-convecting thermosiphons that directly convert reservoir heat to mechanical energy for fluid recirculation. Stored pressure drives fluid production and responds faster than conventional brine-based geothermal systems. Our design uses concentric rings of horizontal wells to create a hydraulic divide that stores supplemental fluids and pressure. Production and injection wells are controlled to schedule power delivery and time-shift the parasitic power necessary to separate N2 from air and compress it for injection. The parasitic load can be scheduled during minimum power demand or when there is excess electricity from wind or solar. Net power output can nearly equal gross power output during peak demand, and energy storage is almost 100% efficient because it is achieved by the time-shift. Further, per-well production rates can take advantage of the large productivity of horizontal wells, with greater leveraging of well costs, which often constitute a major portion of capital costs for

  2. Fluvial-aeolian interactions in sediment routing and sedimentary signal buffering: an example from the Indus Basin and Thar Desert

    USGS Publications Warehouse

    East, Amy E.; Clift, Peter D.; Carter, Andrew; Alizai, Anwar; VanLaningham, Sam

    2015-01-01

    Sediment production and its subsequent preservation in the marine stratigraphic record offshore of large rivers are linked by complex sediment-transfer systems. To interpret the stratigraphic record it is critical to understand how environmental signals transfer from sedimentary source regions to depositional sinks, and in particular to understand the role of buffering in obscuring climatic or tectonic signals. In dryland regions, signal buffering can include sediment cycling through linked fluvial and eolian systems. We investigate sediment-routing connectivity between the Indus River and the Thar Desert, where fluvial and eolian systems exchanged sediment over large spatial scales (hundreds of kilometers). Summer monsoon winds recycle sediment from the lower Indus River and delta northeastward, i.e., downwind and upstream, into the desert. Far-field eolian recycling of Indus sediment is important enough to control sediment provenance at the downwind end of the desert substantially, although the proportion of Indus sediment of various ages varies regionally within the desert; dune sands in the northwestern Thar Desert resemble the Late Holocene–Recent Indus delta, requiring short transport and reworking times. On smaller spatial scales (1–10 m) along fluvial channels in the northern Thar Desert, there is also stratigraphic evidence of fluvial and eolian sediment reworking from local rivers. In terms of sediment volume, we estimate that the Thar Desert could be a more substantial sedimentary store than all other known buffer regions in the Indus basin combined. Thus, since the mid-Holocene, when the desert expanded as the summer monsoon rainfall decreased, fluvial-eolian recycling has been an important but little recognized process buffering sediment flux to the ocean. Similar fluvial-eolian connectivity likely also affects sediment routing and signal transfer in other dryland regions globally.

  3. Tectonic and sedimentary evolution from the Late Sinian to Early Cambrian and their control on hydrocarbon source rocks in Tarim Basin, Western China

    NASA Astrophysics Data System (ADS)

    Wu, Lin

    2017-04-01

    The lower Cambrian black shale is widely distributed all over the world, but due to the deep buried depth of Cambrian in the Tarim Basin, the black shale, as high-quality source rocks, has never been found in the interior of the basin. Through further survey on outcrops in the periphery of the Tarim Basin, a set of hydrocarbon source rocks with high-quality was found developed at the bottom of the lower Cambrian Yuertusi formation in Tarim basin. Lithology of the source rock is black shale. Its organic carbon (TOC) mainly ranges 2-10%, organic carbon of black shale layer reaches 17%, and the thickness of outcrop is 10-15m in Aksu area. This discovery of hydrocarbon source rocks draws much attention to the oil and gas exploration in Cambrian. The author, integrating with seismic, drilling and geological data, analyzes the tectonic sedimentary evolution in late Sinian-early Cambrian in the basin and its control on formation and distribution of hydrocarbon source rocks in Early Cambrian in this paper. The Nanhua - early Sinian clastic rocks rift basin formed on the basement on Tarim under the control of Rodinia supercontinent tectonic movement. Post-rifting marine carbonate siliceous shale deposited from the late Sinian to Early Cambrian rifting. Wide transgression in Tarim in the late Sinian departed Tarim into two patterns in North and South with the central land as a boundary with structural features: higher topography in middle and lower topography in two sides. There was no change in the pattern of basin during the late Sinian tectonic movement, and the Cambrian sediments deposited and filled the basin in this period. The central ancient land with structural high topography formed angular unconformity, while the basin with low topography formed parallel unconformity. Therefore, the Early Cambrian sedimentary filling in the late Sinian basin overlapped from low topography to high topography. Their distribution patterns were similar, both of which were of great

  4. Drainage architecture and sediment routing in erosive catchments within the Ebro Eiver sedimentary basin (NE Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Castelltort, Xavier; Colombo, Ferran; Carles Balasch Solanes, Josep

    2016-04-01

    The Ebro Basin (EB) is the result of filling a foreland basin located between active mountain ranges during the Paleogene compressive phases, and later affected by phases of distension in the Neogene. The arrangement of filler material is monocline in the eastern margin and in the contact with the Catalan Coastal Range (CCR). This has repercussions on the model of emptying the erosive basins and in the drainage that took place in the margins of the original sedimentary basin. One can speak of a drainage architecture and sediment routing associated to a monocline erosive basin model. The monocline topography in the original margin of EB encouraged the formation of a string of erosive basins around the contact with CCR, which are the result of headward erosion towards the center of the EB of the rivers draining the CCR towards the Valencia Trough. At the time, the transition from the EB in its initial condition of endorheic to exorheic was through one of these monocline erosive basins. The erosive basins emptied by means of two vectors. On the one hand, growth in surface of the basin by deepening anaclinal streams through resistant beds of monocline stratigraphic succession that empty and link small depressions that increase laterally on the less resistant lithologic member. Moreover, the new drainage system entrenches as the exit point of the basin does, thanks to gradients created by distensional movements of the Neogene Valencia Trough. Growth and entrenchment model of river basins, as well as, sedimentary deposits and landforms generated by these processes are described and analyzed.

  5. 1-D/3-D geologic model of the Western Canada Sedimentary Basin

    USGS Publications Warehouse

    Higley, D.K.; Henry, M.; Roberts, L.N.R.; Steinshouer, D.W.

    2005-01-01

    The 3-D geologic model of the Western Canada Sedimentary Basin comprises 18 stacked intervals from the base of the Devonian Woodbend Group and age equivalent formations to ground surface; it includes an estimated thickness of eroded sediments based on 1-D burial history reconstructions for 33 wells across the study area. Each interval for the construction of the 3-D model was chosen on the basis of whether it is primarily composed of petroleum system elements of reservoir, hydrocarbon source, seal, overburden, or underburden strata, as well as the quality and areal distribution of well and other data. Preliminary results of the modeling support the following interpretations. Long-distance migration of hydrocarbons east of the Rocky Mountains is indicated by oil and gas accumulations in areas within which source rocks are thermally immature for oil and (or) gas. Petroleum systems in the basin are segmented by the northeast-trending Sweetgrass Arch; hydrocarbons west of the arch were from source rocks lying near or beneath the Rocky Mountains, whereas oil and gas east of the arch were sourced from the Williston Basin. Hydrocarbon generation and migration are primarily due to increased burial associated with the Laramide Orogeny. Hydrocarbon sources and migration were also influenced by the Lower Cretaceous sub-Mannville unconformity. In the Peace River Arch area of northern Alberta, Jurassic and older formations exhibit high-angle truncations against the unconformity. Potential Paleozoic though Mesozoic hydrocarbon source rocks are in contact with overlying Mannville Group reservoir facies. In contrast, in Saskatchewan and southern Alberta the contacts are parallel to sub-parallel, with the result that hydrocarbon source rocks are separated from the Mannville Group by seal-forming strata within the Jurassic. Vertical and lateral movement of hydrocarbons along the faults in the Rocky Mountains deformed belt probably also resulted in mixing of oil and gas from numerous

  6. Cenozoic uplift on the West Greenland margin: active sedimentary basins in quiet Archean terranes.

    NASA Astrophysics Data System (ADS)

    Jess, Scott; Stephenson, Randell; Brown, Roderick

    2016-04-01

    The North Atlantic is believed by some authors to have experienced tectonically induced uplift within the Cenozoic. Examination of evidence, onshore and offshore, has been interpreted to imply the presence of kilometre scale uplift across the margins of the Barents Sea, North Sea, Baffin Bay and Greenland Sea. Development of topography on the West Greenland margin (Baffin Bay), in particular, has been subject to much discussion and dispute. A series of low temperature thermochronological (AFT and AHe) studies onshore and interpretation of seismic architecture offshore have suggested uplift of the entire margin totalling ~3km. However, challenges to this work and recent analysis on the opposing margin (Baffin Island) have raised questions about the validity of this interpretation. The present work reviews and remodels the thermochronological data from onshore West Greenland with the aim of re-evaluating our understanding of the margin's history. New concepts within the discipline, such as effect of radiation damage on Helium diffusivity, contemporary modelling approaches and denudational mapping are all utilised to investigate alternative interpretations to this margins complex post rift evolution. In contrast to earlier studies our new approach indicates slow protracted cooling across much of the region; however, reworked sedimentary samples taken from the Cretaceous Nuussuaq Basin display periods of rapid reheating and cooling. These new models suggest the Nuussuaq Basin experienced a tectonically active Cenozoic, while the surrounding Archean basement remained quiet. Faults located within the basin appear to have been reactivated during the Palaeocene and Eocene, a period of well-documented inversion events throughout the North Atlantic, and may have resulted in subaerial kilometre scale uplift. This interpretation of the margin's evolution has wider implications for the treatment of low temperature thermochronological data and the geological history of the North

  7. Framework for the assessment of interaction between CO2 geological storage and other sedimentary basin resources.

    PubMed

    Michael, K; Whittaker, S; Varma, S; Bekele, E; Langhi, L; Hodgkinson, J; Harris, B

    2016-02-01

    Sedimentary basins around the world considered suitable for carbon storage usually contain other natural resources such as petroleum, coal, geothermal energy and groundwater. Storing carbon dioxide in geological formations in the basins adds to the competition for access to the subsurface and the use of pore space where other resource-based industries also operate. Managing potential impacts that industrial-scale injection of carbon dioxide may have on other resource development must be focused to prevent potential conflicts and enhance synergies where possible. Such a sustainable coexistence of various resource developments can be accomplished by implementing a Framework for Basin Resource Management strategy (FBRM). The FBRM strategy utilizes the concept of an Area of Review (AOR) for guiding development and regulation of CO2 geological storage projects and for assessing their potential impact on other resources. The AOR is determined by the expected physical distribution of the CO2 plume in the subsurface and the modelled extent of reservoir pressure increase resulting from the injection of the CO2. This information is used to define the region to be characterised and monitored for a CO2 injection project. The geological characterisation and risk- and performance-based monitoring will be most comprehensive within the region of the reservoir containing the carbon dioxide plume and should consider geological features and wells continuously above the plume through to its surface projection; this region defines where increases in reservoir pressure will be greatest and where potential for unplanned migration of carbon dioxide is highest. Beyond the expanse of the carbon dioxide plume, geological characterisation and monitoring should focus only on identified features that could be a potential migration conduit for either formation water or carbon dioxide.

  8. Tectonic and Sedimentary Response of the Huangshan Basin to Paleo-Pacific Subduction undernearth Southeast China

    NASA Astrophysics Data System (ADS)

    Xu, X.; Tang, S.; Lin, S.

    2015-12-01

    The subduction of the Paleo-Pacific Plate predominated the Late Mesozoic tectonic evolution of southeast China. This process is well documented by Jurassic-Cretaceous deposition and structural deformation. Zircon U-Pb ages of volcano-sedimentary rocks and fault-slip data of brittle faults were investigated in the Huangshan Basin. Detrital zircon U-Pb ages show that the provenances of the Huangshan Basin changed during Late Jurassic to Early Cretaceous. The source region of Early and Middle Jurassic sediments is mainly the Wuyishan domain to the southeast. But the Early Cretaceous clastic rocks are derived from the Jiangnan domain to the north. The inversions of fault-slip data show that paleostress fields also changed during Late Jurassic to Early Cretaceous. The strike-slip regime with nearly E-W compression and N-S extension predominated in the late Middle Jurassic whereas intense NW-SE-striking extensional one during Early Cretaceous. Moreover, geochemistry and zircon U-Pb ages of Late Jurassic (156~152 Ma) and Early Cretaceous (~130 Ma) felsic volcanic rocks in the Huangshan Basin also argue for a tectonic event occurred during Late Jurassic to Early Cretaceous. Above results imply that the tectonic background of southeast China changed from the initial subduction of the Paleo-Pacific plate during the Early and Middle Jurassic into subsequence back-arc extension in the Early Cretaceous. The paleostress field then changed into the strike-slip regime with N-S compression and E-W extension during late Early Cretaceous, which is caused by the collision between the Philippine and South China blocks. And after that, a weak and short-lived N-S extension was replaced by the strike-slip regime with NW-SE compression and NE-SW extension. Meanwhile, the South China continental margin also changed from an Andean-type to a Western Pacific-type plate boundary in early Late Cretaceous.

  9. Anisotropic mechanical behaviour of sedimentary basins inferred by advanced radar interferometry above gas storage fields

    NASA Astrophysics Data System (ADS)

    Teatini, P.; Gambolati, G.; Ferretti, A.

    2010-12-01

    Natural gas is commonly stored underground in depleted oil and gas fields to provide safe storage capacity and deliverability to market areas where production is limited, or to take advantage of seasonal price swings. In response to summer gas injection and winter gas withdrawal the reservoir expands and contracts with the overlying land that moves accordingly. Depending on the field burial depth, a few kilometres of the upper lithosphere are subject to local three-dimensional deformations with the related cyclic motion of the ground surface being both vertical and horizontal. Advanced Persistent Scatterer Interferometry (PSI) data, obtained by combining ascending and descending RADARSAT-1 images acquired from 2003 to 2008 above gas storage fields located in the sedimentary basin of the Po river plain, Italy, provide reliable measurement of these seasonal vertical ups and downs as well as horizontal displacements to and from the injection/withdrawal wells. Combination of the land surface movements together with an accurate reconstruction of the subsurface geology made available by three-dimensional seismic surveys and long-time records of fluid pore pressure within the 1000-1500 m deep reservoirs has allowed for the development of an accurate 3D poro-mechanical finite-element model of the gas injection/removal occurrence. Model calibration based on the observed cyclic motions, which are on the range of 10-15 mm and 5-10 mm in the vertical and horizontal west-east directions, respectively, helps characterize the nonlinear hysteretic geomechanical properties of the basin. First, using a basin-scale relationship between the oedometric rock compressibility cM in virgin loading conditions versus the effective intergranular stress derived from previous experimental studies, the modeling results show that the ratio s between loading and unloading-reloading cM is about 4, consistent with in-situ expansions measured by the radioactive marker technique in similar reservoirs

  10. Magnetostratigraphic and paleoenvironmental records for a Late Cenozoic sedimentary sequence drilled from Lop Nor in the eastern Tarim Basin

    NASA Astrophysics Data System (ADS)

    Chang, Hong; An, Zhisheng; Liu, Weiguo; Qiang, Xiaoke; Song, Yougui; Ao, Hong

    2012-01-01

    The Tarim Basin, one of the largest inland basins in the world, is situated in the northwestern China and to the north of the Tibetan Plateau. Continuous Cenozoic deposits have accumulated in this basin, which are crucial for investigating the growth of the Tibetan Plateau and the paleoclimatic evolution in Asian interior. Here we report the magnetostratigraphic and paleoenvironmental records for a Late Cenozoic sedimentary sequence drilled from Lop Nor in the eastern Tarim Basin. Magnetostratigraphic results show that this core has recorded a magnetic polarity sequence from C3Bn to C1n, covering an age range from ca. 7 Ma to the present. Decreased magnetic susceptibility occurred after ca. 5.6-5.1 Ma, which was interpreted to indicate an enhancement of aridity in the Tarim Basin since this period. We attribute this aridification to the combined effect of global climate cooling and the uplift of the Northern Tibetan Plateau since the late Miocene.

  11. Natural radionuclides in major aquifer systems of the Paraná sedimentary basin, Brazil.

    PubMed

    Bonotto, Daniel Marcos

    2011-10-01

    This paper describes the natural radioactivity of groundwater occurring in sedimentary (Bauru and Guarani) and fractured rock (Serra Geral) aquifer systems in the Paraná sedimentary basin, South America that is extensively used for drinking purposes, among others. The measurements of gross alpha and gross beta radioactivity as well the activity concentration of the natural dissolved radionuclides ⁴⁰K, ²³⁸U, ²³⁴U, ²²⁶Ra, ²²²Rn, ²¹⁰Po and ²¹⁰Pb were held in 80 tubular wells drilled in 21 municipalities located at São Paulo State and its border with Mato Grosso do Sul State in Brazil. Most of the gross alpha radioactivity data were below 1 mBq/L, whereas values exceeding the gross beta radioactivity detection limit of 30 mBq/L were found. The radioelement solubility in the studied systems varied according to the sequence radon>radium>other radionuclides and the higher porosity of sandstones relatively to basalts and diabases could justify the enhanced presence of dissolved radon in the porous aquifer. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed. The population-weighted average activity concentration for these radionuclides was compared to the guideline value of 0.1 mSv/yr for the total effective dose and discussed in terms of the choice of the dose conversion factors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Late Paleozoic paleofjord in the southernmost Parana Basin (Brazil): Geomorphology and sedimentary fill

    NASA Astrophysics Data System (ADS)

    Tedesco, Julia; Cagliari, Joice; Coitinho, Julia dos Reis; da Cunha Lopes, Ricardo; Lavina, Ernesto Luiz Correa

    2016-09-01

    In the southernmost part of the Parana Basin, records of the late Paleozoic glaciation occur in a discontinuous form preserved in paleovalley systems excavated in the crystalline basement. This paper addresses one of these paleovalleys, the Mariana Pimentel, which extends over 60 km with NW-SE valley direction and a constant width of 2.5 km. With the objective of demonstrating that the paleovalley worked as a fjord during the glaciation period, its origin as well as sedimentary fill and morphology were analyzed. The paleovalley morphology was obtained through electrical resistivity (electrical sounding and lateral mapping) and mathematical modeling in four transverse sections. The morphology of the paleovalley documented by the U-shape, steady width, and high depth reaching up to 400 m are typical features of modern glacial valleys. The sedimentary facies that fill the base of the paleovalley, such as rhythmites and dropstones with thickness up to 70 m and diamictites with faceted pebbles (up to 5 m thick) are signs of its glacial origin. During the glaciation period, the paleovalley had a connection to the epicontinental sea located to the northwest, extended toward Namibia, and was excavated by glaciers from the highlands of this region. Thus, the evidence attests that the Mariana Pimentel paleovalley was a fjord during the late Paleozoic glaciation. The duration of the late Paleozoic glaciation (which is longer than the Quaternary glaciation), the apatite fission track that suggests erosion up to 4 km thick in the study area, and the lack of preserved hanging valleys in the Mariana Pimentel indicate that the paleovalley once featured a higher dimension. Furthermore, the existence of paleofjords excavated in the border of the basement corroborates the idea of small ice centers controlled by topography during the late Paleozoic glaciation.

  13. Assessing zircon fission track analysis as a paleotemperature tool for sedimentary basins

    SciTech Connect

    Green, P.F.; Hegarty, K.A.; Duddy, I.R. ); Foland, S.A. )

    1996-01-01

    Apatite Fission Track Analysis (AFTA) is well established for investigating thermal histories in sedimentary basins, in the time-temperature realm relevant to generation of oil and gas. An advantage of AFTA is the ability to provide direct determination of the timing, as well as the magnitude of maximum paleotemperatures. This timing information often cannot be obtained from other methods. Zircon is also suitable for fission track analysis, being a common uranium-bearing detrital mineral, and fission track ages can readily be determined. However for many years, the precise thermal stability of fission tracks in zircon has been uncertain. Estimates of the temperature required to remove or [open quote]anneal[close quote] tracks over timescales of the order of 1 Ma vary from 175[degrees]C or less, to 250[degrees]C or above. We have investigated the thermal stability of fission tracks in zircon in geological conditions by comparing ZFTA data with Vitrinite Reflectance (VR) data from sedimentary sequences which have been subjected to profound geological heating. Onset of significant fission track age reduction occurs at VR values of [approximately]6%, while total annealing is equivalent to [approximately]8% R[sub o]max. These results are consistent with extrapolation of recently published laboratory-based kinetic models which suggest that tracks in zircon should be stable to temperatures in excess of 300[degrees]C for 1 to 10 Me. Such paleotemperatures are outside the range normally encountered in hydrocarbon exploration provinces, although ZFTA has found practical application in a number of areas where improved knowledge of the thermal stability has provided new insights.

  14. The first deep heat flow determination in crystalline basement rocks beneath the Western Canadian Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Majorowicz, Jacek; Chan, Judith; Crowell, James; Gosnold, Will; Heaman, Larry M.; Kück, Jochem; Nieuwenhuis, Greg; Schmitt, Douglas R.; Unsworth, Martyn; Walsh, Nathaniel; Weides, Simon

    2014-05-01

    Heat flow (Q) determined from bottom-hole temperatures measured in oil and gas wells in Alberta show a large scatter with values ranging from 40 to 90 mW m-2. Only two precise measurements of heat flow were previously reported in Alberta, and were made more than half a century ago. These were made in wells located near Edmonton, Alberta, and penetrated the upper kilometre of clastic sedimentary rocks yielding heat flows values of 61 and 67 mW m-2 (Garland & Lennox). Here, we report a new precise heat flow determination from a 2363-m deep well drilled into basement granite rocks just west of Fort McMurray, Alberta (the Hunt Well). Temperature logs acquired in 2010-2011 show a significant increase in the thermal gradient in the granite due to palaeoclimatic effects. In the case of the Hunt Well, heat flow at depths >2200 m is beyond the influence of the glacial-interglacial surface temperatures. Thermal conductivity and temperature measurements in the Hunt Well have shown that the heat flow below 2.2 km is 51 mW m-2 (±3 mW m-2), thermal conductivity measured by the divided bar method under bottom of the well in situ like condition is 2.5 W m-1 K-1, and 2.7 W m-1 K-1 in ambient conditions), and the geothermal gradient was measured as 20.4 mK m-1. The palaeoclimatic effect causes an underestimate of heat flow derived from measurements collected at depths shallower than 2200 m, meaning other heat flow estimates calculated from basin measurements have likely been underestimated. Heat production (A) was calculated from spectral gamma recorded in the Hunt Well granites to a depth of 1880 m and give an average A of 3.4 and 2.9 μW m-3 for the whole depth range of granites down to 2263 m, based on both gamma and spectral logs. This high A explains the relatively high heat flow measured within the Precambrian basement intersected by the Hunt Well; the Taltson Magmatic Zone. Heat flow and related heat generation from the Hunt Well fits the heat flow-heat generation

  15. Late paleozoic tectonic amalgamation of northwestern China. Sedimentary record of the northern Tarim, northwestern Turpan, and southern Junggar basins

    SciTech Connect

    Carroll, A.R.; Graham, S.A.; Hendrix, M.S.; Ying, D.; Zhou, D.

    1995-05-01

    This study focuses on areas adjacent to the Tian Shan (shan is Chinese for mountains) in Xinjiang Uygur Autonomous Region, northwestern China, and provides new field data on Carboniferous and Permian outcrop exposures of sedimentary rocks of the southern Junggar, northwestern Turpan, and northern Tarim basins that bear directly on the history of late Paleozoic tectonic amalgamation. We present here a multifaceted sedimentary basin analysis, including sedimentary facies, paleocurrent, and sandstone provenance analyses, and reconstructions of late Paleozoic basin subsidence. These data provide a unique record not only of the basins themselves, but also of the evolution of the adjacent orogenic belts. This study is based on fieldwork during the summers of 1987, 1988, 1991, and 1992 by workers from Stanford University, the Chinese Academy of Geological Sciences, and the Xinjiang Bureau of Geology and Mineral Resources. Although reconnaissance in nature, the data presented here provide a basis for evaluating alternative hypotheses for the evolution of northwestern China and provide a starting point for more comprehensive future studies. 72 refs., 18 figs., 1 tab.

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Anatomy of mass transport deposits in the Dead Sea: sedimentary processes in an active tectonic hypersaline basin

    NASA Astrophysics Data System (ADS)

    Waldmann, Nicolas; Hadzhiivanova, Elitsa; Neugebauer, Ina; Brauer, Achim; Schwab, Markus; Frank, Ute; Dulski, Peter

    2014-05-01

    Continental archives such as interplate endorheic lacustrine sedimentary basins provide an excellent source of data for studying regional climate, seismicity and environmental changes through time. Such is the case for the sediments that were deposited in the Dead Sea basin, a tectonically active pull-apart structure along the Dead Sea fault (DSF). This elongated basin is characterized by steep slopes and a deep and flat basin-floor, which are constantly shaped by seismicity and climate. In this study, we present initial results on the sedimentology and internal structure of mass transport deposits in the Pleistocene Dead Sea. The database used for this study consists of a long core retrieved at ~300 m water depth in the deepest part of the Dead Sea as part of an international scientific effort under the auspice of the ICDP. Micro-facies analysis coupled by elemental scanning (µXRF), granulometry and petrophysical measurements (magnetic susceptibility) have been carried out on selected intervals in order to decipher and identify the source-to-sink processes and controlling mechanisms behind the formation of mass transport deposits. The findings of this study allowed defining and characterizing the mass transport deposits into separate sedimentary facies according to the lake level and limnological conditions. Investigating sediments from the deep Dead Sea basin allowed better understanding and deciphering the depositional processes in relation with the tectonic forces shaping this basin.

  18. Origin and time-space distribution of hydrothermal systems in east-central Australian sedimentary basins: Constraints from illite geochronology and isotope geochemistry.

    NASA Astrophysics Data System (ADS)

    Uysal, I. Tonguç

    2016-04-01

    Some well-known precious mineral deposits and hydrocarbon resources occur extensively in east-central Australian sedimentary Basins. The metal occurrences are abundant in northwestern and eastern part of Queensland, whereas no significant deposits are known in large areas further south, which may, however, be hidden beneath the Jurassic-Cretaceous sedimentary basins. Important hydrocarbon resources exist within the Jurassic-Cretaceous sedimentary rocks at relatively shallow depths, of which the distribution represent zones of high paleo-geothermal gradients. This study examines the time-space distribution in relation to the regional tectonic history of concealed metal deposits and areas of high paleo-geothermal gradient leading to hydrocarbon maturation. To this end, authigenic illitic clay minerals representing various locations and stratigraphic depths in east-central Australia were investigated, of which the Rb-Sr and Ar-Ar geochronology and stable isotope geochemistry assist in delineating zones of hydrothermal systems responsible for hydro-carbon maturation/migration and potentially ore deposition. The Late Carboniferous - Early Permian crustal extension that affected large areas of eastern Australia and led to the epithermal mineralisations (e.g., the Drummond Basin) is also recorded in northern South Australia and southwest Queensland. A Late Triassic - Early Jurassic tectonic event being responsible for coal maturation and gas generation in the Bowen Basin and the epithermal mineralisation in the North Arm goldfield in SE Queensland likewise affected the areas much further west in Queensland. Some illites from the basement in outback Queensland and fault gouges from the Demon Fault in NE New South Wales yield younger Rb-Sr and Ar-Ar ages indicating the effect of hydrothermal processes as a result of a Middle-Upper Jurassic tectonic event. The majority of illite samples from the crystalline basement rocks, Permian Cooper Basin, and Jurassic

  19. Development and hydrocarbon potential of Mesozoic sedimentary basins around margins of North Atlantic

    SciTech Connect

    Masson, D.G.; Miles, P.R.

    1986-06-01

    The Late Triassic-Early Jurassic rift basins of Iberia, offshore eastern Canada, and the continental shelf of western Europe are fragments of a formerly coherent northeast-trending rift system that probably formed as a result of tensional stress between Europe, Africa, and North America. The separation of Europe, North America, and Iberia was preceded by a Late Jurassic-Early Cretaceous rifting phase that is clearly distinct from the earlier Mesozoic rifting episode and was little influenced by it. The two periods of rifting are separated by a Middle Jurassic relatively tectonically quiet period. The distribution of hydrocarbon finds within the rift basin suggests that the best prospects are in areas where the two rifting episodes are superimposed. Lack of mature source rocks in the later Mesozoic rift basins and an unfavorable temporal relationship between hydrocarbon generation and tectonic activity in the early Mesozoic basins are proposed as explanations for the apparently poor hydrocarbon prospectivity of large areas of the Mesozoic basins.

  20. Integrated workflow for characterizing and modeling a mixed sedimentary system: The Ilerdian Alveolina Limestone Formation (Graus-Tremp Basin, Spain)

    NASA Astrophysics Data System (ADS)

    Hamon, Youri; Deschamps, Remy; Joseph, Philippe; Doligez, Brigitte; Schmitz, Julien; Lerat, Olivier

    2016-09-01

    This paper proposes an advanced stochastic workflow to jointly model sedimentary facies and diagenesis. The formation of interest is the Early Eocene Alveolina Limestone Formation, which outcrops in the Serraduy area (Graus-Tremp Basin, NE Spain). Ten sedimentary lithotypes representing facies or facies associations of a mixed siliciclastic-carbonate ramp system were identified within the succession. A 3D model describing the depositional architecture is also proposed. The results from the diagenetic study evidenced the occurrence of several successive calcite cements, which were grouped into five diagenetic imprints for modeling. These imprints were then quantified to ease their integration into numerical models. The following step consisted in building a 3D gridded model with seven different modeling units. They were populated using a bi-plurigaussian simulation approach that reproduced both the sedimentary organization and the observed diagenetic imprint distributions. Last, the simulation results were validated referring to paleogeographic and diagenetic conceptual maps.

  1. Large Sanjiang basin groups outside of the Songliao Basin Meso-Senozoic Tectonic-sediment evolution and hydrocarbon accumulation

    NASA Astrophysics Data System (ADS)

    Zheng, M.; Wu, X.

    2015-12-01

    The basis geological problem is still the bottleneck of the exploration work of the lager Sanjiang basin groups. In general terms, the problems are including the prototype basins and basin forming mechanism of two aspects. In this paper, using the field geological survey and investigation, logging data analysis, seismic data interpretation technical means large Sanjiang basin groups and basin forming mechanism of the prototype are discussed. Main draw the following conclusions: 1. Sanjiang region group-level formation can be completely contrasted. 2. Tension faults, compressive faults, shear structure composition and structure combination of four kinds of compound fracture are mainly developed In the study area. The direction of their distribution can be divided into SN, EW, NNE, NEE, NNW, NWW to other groups of fracture. 3. Large Sanjiang basin has the SN and the EW two main directions of tectonic evolution. Cenozoic basins in Sanjiang region in group formation located the two tectonic domains of ancient Paleo-Asian Ocean and the Pacific Interchange. 4. Large Sanjiang basin has experienced in the late Mesozoic tectonic evolution of two-stage and nine times. The first stage, developmental stage basement, they are ① Since the Mesozoic era and before the Jurassic; ② Early Jurassic period; The second stage, cap stage of development, they are ③ Late Jurassic depression developmental stages of compression; ④ Early Cretaceous rifting stage; ⑤ depression in mid-Early Cretaceous period; ⑥ tensile Early Cretaceous rifting stage; ⑦ inversion of Late Cretaceous tectonic compression stage; ⑧ Paleogene - Neogene; ⑨ After recently Ji Baoquan Sedimentary Ridge. 5. Large Sanjiang basin group is actually a residual basin structure, and Can be divided into left - superimposed (Founder, Tangyuan depression, Hulin Basin), residual - inherited type (Sanjiang basin), residual - reformed (Jixi, Boli, Hegang basin). there are two developed depression and the mechanism

  2. Microbial methane formation in deep aquifers of a coal-bearing sedimentary basin, Germany

    PubMed Central

    Gründger, Friederike; Jiménez, Núria; Thielemann, Thomas; Straaten, Nontje; Lüders, Tillmann; Richnow, Hans-Hermann; Krüger, Martin

    2015-01-01

    Coal-bearing sediments are major reservoirs of organic matter potentially available for methanogenic subsurface microbial communities. In this study the specific microbial community inside lignite-bearing sedimentary basin in Germany and its contribution to methanogenic hydrocarbon degradation processes was investigated. The stable isotope signature of methane measured in groundwater and coal-rich sediment samples indicated methanogenic activity. Analysis of 16S rRNA gene sequences showed the presence of methanogenic Archaea, predominantly belonging to the orders Methanosarcinales and Methanomicrobiales, capable of acetoclastic or hydrogenotrophic methanogenesis. Furthermore, we identified fermenting, sulfate-, nitrate-, and metal-reducing, or acetogenic Bacteria clustering within the phyla Proteobacteria, complemented by members of the classes Actinobacteria, and Clostridia. The indigenous microbial communities found in the groundwater as well as in the coal-rich sediments are able to degrade coal-derived organic components and to produce methane as the final product. Lignite-bearing sediments may be an important nutrient and energy source influencing larger compartments via groundwater transport. PMID:25852663

  3. Anisotropic P-wave velocity analysis and seismic imaging in onshore Kutch sedimentary basin of India

    NASA Astrophysics Data System (ADS)

    Behera, Laxmidhar; Khare, Prakash; Sarkar, Dipankar

    2011-08-01

    The long-offset P-wave seismic reflection data has observable non-hyperbolic moveout, which depend on two parameters such as normal moveout velocity ( Vnmo) and the anisotropy parameter( η). Anisotropy (e.g., directional dependence of velocity at a fixed spatial location in a medium) plays an important role in seismic imaging. It is difficult to know the presence of anisotropy in the subsurface geological formations only from P-wave seismic data and special analysis is required for this. The presence of anisotropy causes two major distortions of moveout in P-wave seismic reflection data. First, in contrast to isotropic media, normal-moveout (NMO) velocity differs from the vertical velocity; and the second is substantial increase of deviations in hyperbolic moveout in an anisotropic layer. Hence, with the help of conventional velocity analysis based on short-spread moveout (stacking) velocities do not provide enough information to determine the true vertical velocity in a transversely isotropic media with vertical symmetry axis (VTI media). Therefore, it is essential to estimate the single anisotropic parameter ( η) from the long-offset P-wave seismic data. It has been demonstrated here as a case study with long-offset P-wave seismic data acquired in onshore Kutch sedimentary basin of western India that suitable velocity analysis using Vnmo and η can improve the stacking image obtained from conventional velocity analysis.

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

    NASA Astrophysics Data System (ADS)

    Sobrinho, R. L.; Bernardes, M. C.; Abril, G.; Kim, J.-H.; Zell, C. I.; Mortillaro, J.-M.; Meziane, T.; Moreira-Turcq, P.; Sinninghe Damsté, J. S.

    2016-01-01

    In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochemical tracers such as the C : N ratio and the stable isotopic composition of organic carbon (δ13Corg). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indicator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derived OM contribution was observed along the gradient of increasing open waters - i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.

  5. A reaction kinetic approach to the temperature-time history of sedimentary basins

    NASA Astrophysics Data System (ADS)

    Sajgó, Cs.; Lefler, J.

    Three biological marker reactions have been studied in order to determine the temperature — time history of a sedimentary sequence. Two of these reactions are configurational isomerization reactions, at C-20 in a C29-sterane and at C-22 in C31 and C32 hopane hydrocarbons. In the third reaction two C29 C-ring monoaromatic steroid hydrocarbons convert to a C28 triaromatic one. The progress of these reactions is different because of their different rate constants. Based on temperature and age data obtained from field measurements and on concentration measurements of reactants and products in core samples of a Pannonian borehole, we calculated the rate parameters: pre-exponential factors, enthalpies and entropies of activation. It is obvious, that at least two different reactions are necessary to characterize the maturity of any system. The aromatization seems to be a rather complicated reaction, and we believe its use to be premature. Fortunately, two isomerizations work well and are suitable for elucidation of thermal history in different basins if the rate constants are universally valid.

  6. Microbial methane formation in deep aquifers of a coal-bearing sedimentary basin, Germany.

    PubMed

    Gründger, Friederike; Jiménez, Núria; Thielemann, Thomas; Straaten, Nontje; Lüders, Tillmann; Richnow, Hans-Hermann; Krüger, Martin

    2015-01-01

    Coal-bearing sediments are major reservoirs of organic matter potentially available for methanogenic subsurface microbial communities. In this study the specific microbial community inside lignite-bearing sedimentary basin in Germany and its contribution to methanogenic hydrocarbon degradation processes was investigated. The stable isotope signature of methane measured in groundwater and coal-rich sediment samples indicated methanogenic activity. Analysis of 16S rRNA gene sequences showed the presence of methanogenic Archaea, predominantly belonging to the orders Methanosarcinales and Methanomicrobiales, capable of acetoclastic or hydrogenotrophic methanogenesis. Furthermore, we identified fermenting, sulfate-, nitrate-, and metal-reducing, or acetogenic Bacteria clustering within the phyla Proteobacteria, complemented by members of the classes Actinobacteria, and Clostridia. The indigenous microbial communities found in the groundwater as well as in the coal-rich sediments are able to degrade coal-derived organic components and to produce methane as the final product. Lignite-bearing sediments may be an important nutrient and energy source influencing larger compartments via groundwater transport.

  7. Stagnant lid convection and the thermal subsidence of sedimentary basins with reference to Michigan

    NASA Astrophysics Data System (ADS)

    Sleep, Norman H.

    2009-12-01

    The thermal subsidence of basins formed above thick continental lithosphere differs from that of young passive margin basins and of young oceanic crust in that stagnant lid convection supplies significant heat flow from the asthenosphere. The lithosphere eventually approaches thermal equilibrium where the convective heat added to its base balances the heat lost by conduction to the surface. This paper presents a simple parameterization that quantifies these effects for modeling basin subsidence. The convective heat flow scales with the current lithosphere thickness squared while the conductive heat flow scales inversely to current lithospheric thickness. The predicted thermal subsidence rate scales to the difference between the conductive and convective heat flows and wanes gradually over hundreds of millions of years. The formalism can be modified to represent thermal subsidence where plume material has ponded within a catchment of locally thinned lithosphere. The base of the plume material forms a stable stratification that suppresses convective heat flow from below while heat continues to conduct to the surface by conduction. The predicted initial thermal subsidence rate scales with the large difference between conductive and zero convective heat flow. It is thus much greater than beneath lithosphere underlain by ordinary asthenosphere for a given amount of total eventual thermal subsidence. The paper compares thermal subsidence predictions from the models with and without plumes with sedimentation data from the Michigan basin. Observed initial Late Cambrian through Lower Devonian sedimentation in the Michigan basin is rapid as expected from the plume model, but the Ordovician sedimentation rate is slower than before and after. It is conceivable that this irregularity in the sedimentation curve is associated with low eustatic sea level and sediment-starved conditions at the basin center in the Ordovician and Early Silurian periods, as opposed to irregular

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  9. Sedimentary model for Eocene exotic blocks of carbonates and turbiditic carbonate deposits in the South Sistan Basin, SE Iran

    NASA Astrophysics Data System (ADS)

    Mohammadi, Ali; Burg, Jean-Pierre; Bernoulli, Daniel

    2016-04-01

    The N-S-trending Sistan Suture Zone in east Iran results from collision of the Lut Block to the west with the Afghan Block to the east. Extensive Eocene turbiditic sequences with numerous exotic carbonate olistholiths and carbonate debris flows in the southern part of the Sistan Basin (so-called Neh Accretionary Wedge) were deposited in a deep-marine environment. Litho-biostratigraphy of the exotic carbonate blocks and carbonate debris flows with surrounding sandstones aims to develop a paleoenvironmental model for the South Sistan sedimentary basin. The olistholiths, of Early to Middle Eocene age, are derived from one or more carbonate platforms including inner shelf (protected platform), shelf margin (coral reefs, skeletal sand bars) and upper slope deposits. In addition, the terrigenous turbidites that form the background sediments of the basinal deposits are interlayered with carbonate mass-flow deposits, lime turbidites and scarcer pelagic limestones with planktonic foraminifera of Eocene age showing that the mass-flow events contemporaneous with platform evolution. The absence of terrigenous detritus and of volcanic material in the platform limestones and related mass-flow deposits suggests that the carbonate platform was presumably located on the Kuh-e-Birk passive margin, to the southwest of the Sistan Basin. Key words: South Sistan Basin, sedimentary model, Eocene, olistostrome, carbonate platform

  10. Accretionary prism-forearc interactions as reflected in the sedimentary fill of southern Thrace Basin (Lemnos Island, NE Greece)

    NASA Astrophysics Data System (ADS)

    Maravelis, A. G.; Pantopoulos, G.; Tserolas, P.; Zelilidis, A.

    2015-06-01

    Architecture of the well-exposed ancient forearc basin successions of northeast Aegean Sea, Greece, provides useful insights into the interplay between arc magmatism, accretionary prism exhumation, and sedimentary deposition in forearc basins. The upper Eocene-lower Oligocene basin fill of the southern Thrace forearc basin reflects the active influence of the uplifted accretionary prism. Deep-marine sediments predominate the basin fill that eventually shoals upwards into shallow-marine sediments. This trend is related to tectonically driven uplift and compression. Field, stratigraphic, sedimentological, petrographic, geochemical, and provenance data on the lower Oligocene shallow-marine deposits revealed the accretionary prism (i.e. Pindic Cordillera or Biga Peninsula) as the major contributor of sediments into the forearc region. Field investigations in these shallow-marine deposits revealed the occurrence of conglomerates with: (1) mafic and ultramafic igneous rock clasts, (2) low-grade metamorphic rock fragments, and (3) sedimentary rocks. The absence of felsic volcanic fragments rules out influence of a felsic source rock. Geochemical analysis indicates that the studied rocks were accumulated in an active tectonic setting with a sediment source of mainly mafic composition, and palaeodispersal analysis revealed a NE-NNE palaeocurrent trend, towards the Rhodopian magmatic arc. Thus, these combined provenance results make the accretionary prism the most suitable candidate for the detritus forming these shallow-marine deposits.

  11. Sedimentary geochemistry depicts 2700 years of regional climate and land use change in the Rieti Basin, Central Italy

    NASA Astrophysics Data System (ADS)

    Archer, C.; Noble, P. J.; Mensing, S. A.; Tunno, I.; Sagnotti, L.; Florindo, F.; Cifnani, G.; Zimmerman, S. R. H.; Piovesan, G.

    2014-12-01

    A 14.4 m thick sedimentary sequence was recovered in multiple cores from Lago Lungo in the Rieti Basin, an intrapenninic extensional basin ~80 km north of Rome, Italy. This sequence provides a high-resolution record of environmental change related to climatic influence and anthropogenic landscape alteration. Pollen analyses, corroborated with historical records of land-use change, define the major shifts in forest composition and their historical context. An age model of the sequence was built using ties to regional cultigen datums and archaeomagnetic reference curves. Here we focus on sedimentologic and geochemical data (scanning XRF) from the Roman Period through the Little Ice Age (LIA). The base of the sequence (ca. 680 BCE- 1 CE) is marked by a steady increase in fine-grained detrital elements Ti, Rb, and K, and corresponding decrease in Ca, representing a transition from the unaltered system after the Romans constructed a channel that the basin. The Medieval Period (MP; 900-1350 CE) is lithologically distinct, composed of varicolored bands of alternating silt, clay, and calcareous concretions. Low counts of Ca, high detrital elements and frequent abrupt peaks in levels of the redox elements Fe and Mn indicate episodic clastic influx. Pollen data indicate that the greatest degree of deforestation and erosion occurred during the MP, supported by mean sedimentation rates of ca. 1cm/year, over twice the rate of the underlying interval. The Medieval climate was warmer and more stable, population increased, and elevations >1000 m were exploited for agriculture. The influence of the Velino River on the lake appears to increase during the MP through channel migration, increased flooding, or increased overland flow. The next transition (1350 CE) marks the start of the LIA and is coincident with the Black Plague. Historical records document a large earthquake in 1349 that severely struck Central Italy, with possible effects on the lake's depositional and hydrochemical

  12. Seismic stratigraphy of sedimentary cover in the southern Amerasia Basin between 140E and 170W

    NASA Astrophysics Data System (ADS)

    Poselov, V.; Butsenko, V.; Kaminskiy, V.; Kireev, A.; Grikurov, G.

    2013-12-01

    Seismic reflection data (MCS) acquired by Russian expeditions in 2007, 2009, 2011 and 2012 are correlated with earlier Polarstern (AWI-91090) and US (78AR_808) lines calibrated by drilling on the Lomonosov Ridge (LR) and in the Chukchi Sea (ACEX hole and POPCORN well, respectively). In the absence of direct intersections between those and Russian lines, the correlation is based on analysis of wave fields. Main seismic horizons and their intervening units are traced throughout the entire study area. The uppermost unconformity in both holes is related to pre-Miocene depositional hiatus at the base of essentially hemipelagic unit. Specific wave characteristics of both the unconformity and overlying sediments are persistently recorded on seismic lines. Hemipelagic drape is typically relatively thin (few hundred meters) but may thicken to ~1,500-2,000 m in some deepwater basins. Another major depositional hiatus spanning ~20 Ma is interpreted in the ACEX hole between the lowermost drilled Campanian and Upper Paleocene units. On seismic records it is recognized as post-Campanian unconformity (pCU) traced along the length of the near-Siberia segment of LR and in deep shelf/margin sedimentary basins of the East Siberian and western Chukchi Seas. Farther east pCU correlates with Mid-Brookian unconformity (MBU) separating the Lower and Upper Brookian terrigenous sequences. In Popcorn well the Upper Brookian is about 1,300 m thick; on the Russian margin a comparable thickness of equivalent Upper Paleocene-Eocene units sandwiched between pCU and pre-Miocene unconformity is observed only in structural lows. Older cover units on the Russian East Arctic margin are not sampled by drilling. Among them only one displays particular wave field features clearly comparable to those observed in the carbonate-dominated Carboniferous-Permian Lisburne Group (LG) of the US Chukchi Sea. This marker sequence is confidently recognized on seismic sections in the North Chukchi Trough (NCT) and

  13. Current channelling and three-dimensional effects detected from magnetotelluric data from a sedimentary basin in Sierras Pampeanas, Argentina

    NASA Astrophysics Data System (ADS)

    Pomposiello, C.; Osella, A.; Favetto, A.; Sainato, C.; Martinelli, P.; Aprea, C.

    1998-11-01

    Aquifer-bearing intermontane sedimentary basins of the Sierras Pampeanas in the northwest of Argentina are in general very deep and narrow and contain economically important deposits of Tertiary sediments. This paper presents the results of a study to characterize the sedimentary basin bounded to the west by Sierra de Famatina and to the east by Sierra de Velasco, where an electromagnetic sensing technique, the magnetotelluric (MT) method, was applied. 12 MT sites were deployed along a 30 km E-W transect. Some of the data collected were used to derive a 2-D resistivity model of the basin. The model shows a subsurface trough with a thick (approximately 8 km) sedimentary sequence above it. Anomalous behaviour of the E-W electric-field component (Ey) was detected in the period range 1-100 s, where the amplitude of this component was below the instrumental noise level. The cause of this anomaly is not known, but it might be due to the presence of an embedded conducting body between 8 and 10 km, which would give rise to N-S current channelling.

  14. Syn-tectonic sedimentary evolution of the Miocene Çatallar Basin, southwestern Turkey

    NASA Astrophysics Data System (ADS)

    Kosun, Erdal; Poisson, André; Çiner, Attila; Wernli, Roland; Monod, Olivier

    2009-03-01

    The Çatallar Basin is one of the Miocene basins located in the southern part of the Bey Dağları Massif (SW Turkey). This basin has been reinvestigated and new stratigraphic and sedimentological data are now presented. The Çatallar Basin lies in paraconformity on the Bey Dağları carbonate platform of Late Cretaceous to Palaeogene age. It consists of an impersistent, shallow-marine carbonate base (Karabayır formation, Late Oligocene to Early Burdigalian) followed by an onlapping detrital sequence including the Akçay and Bağbeleni formations (Langhian to Serravallian). The Akçay formation mainly contains turbidites in which several debris-flows and olistostromes are intercalated. The lowest debris flows derive from the local carbonate platforms of Cretaceous and Palaeogene age. Higher, the debris flows and olistostromes contain large carbonate blocks deriving from nearby sources (Bey Dağları platform carbonates), whereas the accompanying pebbles originate from the allochthonous ophiolitic units located farther to the north (Lycian Nappes) or to the east (Antalya Nappes). The origin of these ophiolitic detritus is a matter of debate. The new data obtained in this study favour a northern origin.

  15. Verification of the Adjoint-tomography Inversion of the Small-scale Surface Sedimentary Structure: The Case of the Mygdonian Basin, Greece

    NASA Astrophysics Data System (ADS)

    Kubina, Filip; Moczo, Peter; Kristek, Jozef

    2015-04-01

    We apply the full-waveform inversion using the adjoint method to the Mygdonian basin, Greece, a local surface sedimentary basin. A canonical perturbation of the 2D EUROSEISTEST model is considered as a true (target) model and numerically simulated seismograms for the model as recorded seismograms. The 2D EUROSEISTEST model itself is taken as a starting model for inversion. The point DC sources are located relatively deeply beneath the basin and receivers are at the free surface. Due to the configuration and relatively strong velocity gradient in sediments, direct waves propagate almost vertically and almost in the same way for all sources. As a consequence, the coverage of the basin by the source-receiver configuration cannot be considered favourable. Resolution of kernels based on direct arrivals in the vertical direction is therefore very weak. It is necessary to use the entire seismograms. The complete wavefield in the basin is complicated and seismic motion considerably prolonged due to multiple reflections resulting in generation and propagation of local surface waves. Consequently, the corresponding kernel is very complicated. Large velocity contrasts and configuration of receivers imply kernel concentration in low-velocity layers near receivers. The spatial complexity of a kernel strongly depends on a seismogram section used for evaluating misfit and can be simplified by smoothing and spatially dependent normalization. Without simplification the inversion may be not converging properly. On the other hand, the simplification reduces the resolution of the inversion. We investigate a balance between a reasonable level of kernel simplification and inversion resolution in order to find practical criteria for the inversion of the local surface sedimentary structures.

  16. Seismic inversion for incoming sedimentary sequence in the Nankai Trough margin off Kumano Basin, southwest Japan

    NASA Astrophysics Data System (ADS)

    Naito, K.; Park, J.

    2012-12-01

    The Nankai Trough off southwest Japan is one of the best subduction-zone to study megathrust earthquake mechanism. Huge earthquakes have been repeated in the cycle of 100-150 years in the area, and in these days the next emergence of the earthquake becomes one of the most serious issue in Japan. Therefore, detailed descriptions of geological structure are urgently needed there. IODP (Integrated Ocean Drilling Program) have investigated this area in the NanTroSEIZE science plan. Seismic reflection, core sampling and borehole logging surveys have been executed during the NanTroSEIZE expeditions. Core-log-seismic data integration (CLSI) is useful for understanding the Nankai seismogenic zone. We use the seismic inversion method to do the CLSI. The seismic inversion (acoustic impedance inversion, A.I. inversion) is a method to estimate rock physical properties using seismic reflection and logging data. Acoustic impedance volume is inverted for seismic data with density and P-wave velocity of several boreholes with the technique. We use high-resolution 3D multi-channel seismic (MCS) reflection data obtained during KR06-02 cruise in 2006, and measured core sample properties by IODP Expeditions 322 and 333. P-wave velocities missing for some core sample are interpolated by the relationship between acoustic impedance and P-wave velocity. We used Hampson-Russell software for the seismic inversion. 3D porosity model is derived from the 3D acoustic impedance model to figure out rock physical properties of the incoming sedimentary sequence in the Nankai Trough off Kumano Basin. The result of our inversion analysis clearly shows heterogeneity of sediments; relatively high porosity sediments on the shallow layer of Kashinosaki Knoll, and distribution of many physical anomaly bands on volcanic and turbidite sediment layers around the 3D MCS survey area. In this talk, we will show 3D MCS, acoustic impedance, and porosity data for the incoming sedimentary sequence and discuss its

  17. A review of stratigraphy and sedimentary environments of the Karoo Basin of South Africa

    NASA Astrophysics Data System (ADS)

    Smith, R. M. H.

    The Karoo Supergroup covers almost two thirds of the present land surface of southern Africa. Its strata record an almost continuous sequence of continental sedimentation that began in the Permo-Carboniferous (280 Ma) and terminated in the early Jurassic 100 million years later. The glacio-marine to terrestrial sequence accumulated in a variety of tectonically controlled depositories under progressively more arid climatic conditions. Numerous vertebrate fossils are preserved in these rocks, including fish, amphibians, primitive aquatic reptiles, primitive land reptiles, more advanced mammal-like reptiles, dinosaurs and even the earliest mammals. Palaeoenvironmental analysis of the major stratigraphic units of the Karoo sequence demonstrates the effects of more localised tectonic basins in influencing depositional style. These are superimposed on a basinwide trend of progressive aridification attributed to the gradual northward migration of southwestern Gondwanaland out of polar climes and accentuated by the meteoric drying effect of the surrounding land masses. Combined with progressive climatic drying was a gradual shrinking of the basin brought about by the northward migration of the subducting palaeo-Pacific margin to the south. Following deposition of the Cape Supergroup in the pre-Karoo basin there was a period of uplift and erosion. At the same time the southern part of Gondwana migrated over the South Pole resulting in a major ice-sheet over the early Karoo basin and surrounding highlands. Glacial sedimentation in both upland valley and shelf depositories resulted in the basal Karoo Dwyka Formation. After glaciation, an extensive shallow sea remained over the gently subsiding shelf fed by large volumes of meltwater. Black clays and muds accumulated under relatively cool climatic conditions (Lower Ecca) with perhaps a warmer "interglacial" during which the distinctive Mesosaurus-bearing, carbonaceous shales of the Whitehill Formation were deposited

  18. Seismic stratigraphy of sedimentary cover in Amerasian Basin based on the results of Russian High Arctic expeditions

    NASA Astrophysics Data System (ADS)

    Poselov, Viktor; Kireev, Artem; Smirnov, Oleg; Butsenko, Viktor; Zholondz, Sergey; Savin, Vasily

    2016-04-01

    Massive amount of multichannel seismic (MCS) data were obtained by Russian High Arct ic expeditions "Arctica-2011", "Acrtica-2012" and "Arctica-2014". More than 40 MCS lines are located in the Amerasian basin and help to substantiate the seismic stratigraphy model of its sedimentary cover. The proposed seismic stratigraphy model was successively determined for the Cenozoic and pre-Cenozoic parts of the sedimentary section and was based on correlation of the Russian MCS data and seismic data documented by boreholes. Cenozoic part of the sedimentary cover is based on correlation of the Russian MCS data and AWI91090 section calibrated by ACEX-2004 boreholes on the Lomonosov Ridge. Two major unconformities are traced. The upper regional unconformity (RU) is associated with a major pre-Miocene hiatus. Another major hiatus is recorded in the borehole section between the Campanian and the Upper Paleocene units. It is recognized as the post-Campanian unconformity (pCU) in the seismic sections. Formation of the regional unconformities is associated with a fundamental change in depositional environment. Formation of RU was initiated by opening of the Fram Strait gateway at the Paleogene/Neogene boundary. Post-Campanian unconformity is linked with the initial stage of the Eurasian Basin opening between the Cretaceous and the Paleogene. Cenozoic sedimentary units are continuously traced from the East-Siberian and Chukchi sea shelves across the transit zone to the Amerasian basin. Paleogene unit (between pCU and RU) is formed under the neritic depositional environment and it is characterized by an extremely small thickness on the Lomonosov Ridge (less than 200 m), on the Mendeleev Rise and in the Podvodnikov Basin (not more than 300-400 m). Neogene unit (above RU) consists of hemipelagic deposits and occupies the essential part of thickness of the Cenozoic section in Podvodnikov and Makarov Basins. Interval velocities in the Paleogene unit vary within 2.8-3.2 km/s, in the

  19. Sedimentary facies and gas accumulation model of Lower Shihezi Formation in Shenguhao area, northern Ordos basin, China

    NASA Astrophysics Data System (ADS)

    Lin, Weibing; Chen, Lin; Lu, Yongchao; Zhao, Shuai

    2017-04-01

    The Lower Shihezi formation of lower Permian series in Shenguhao develops the highest gas abundance of upper Paleozoic in China, which has already commercially produced on a large scale. The structural location of Shenguhao belongs to the transition zone of Yimeng uplift and Yishan slope of northern Ordos basin, China. Based on the data of core, well logging and seismic, the sedimentary facies and gas accumulation model have been studied in this paper. Sedimentary facies analysis shows that the braided delta is the major facies type developed in this area during the period of Lower Shihezi formation. The braided delta can be further divided into two microfacies, distributary channel and flood plain. The distributary channel sandbody develops the characteristics of scour surface, trough cross beddings and normal grading sequences. Its seismic reflection structure is with the shape of flat top and concave bottom. Its gamma-ray logging curve is mainly in a box or bell shape. The flood plain is mainly composed of thick mudstones. Its seismic reflection structure is with the shape of parallel or sub-parallel sheet. Its gamma-ray logging curve is mainly in a linear tooth shape. On the whole, the distribution of sandbody is characterized by large thickness, wide area and good continuity. Based on the analysis of the sea level change and the restoration of the ancient landform in the period of Lower Shihezi formation, the sea level relative change and morphology of ancient landform have been considered as the main controlling factors for the development and distribution of sedimentary facies. The topography was with big topographic relief, and the sea level was relatively low in the early stage of Low Shihezi formation. The sandbody distributed chiefly along the landform depressions. The sandbody mainly developed in the pattern of multiple vertical superpositions with thick layer. In the later stage, landform gradually converted to be flat, and strata tended to be gentle

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

    NASA Astrophysics Data System (ADS)

    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

  1. Discerning Between Water Column and Sedimentary Denitrification in the Santa Barbara Basin Using the Nitrogen Isotopes of Nitrate

    NASA Astrophysics Data System (ADS)

    Knapp, A. N.; Sigman, D. M.; van Geen, L.; McCorkle, D. C.; Brandes, J. A.; Thunell, R. C.

    2001-05-01

    Below its sill depth, the Santa Barbara Basin (SBB) is seasonally anoxic, making the basin suitable for denitrification in both the water column and the sediments. Deviations of nitrate and phosphate concentrations from Redfield ratios provide quantitative estimates of the nitrate consumed by denitrification in the SBB. However, there are no integrative constraints on whether denitrification occurs predominantly in the water column or in the sediments. Associated with a sharp increase in the nitrate deficit across the oxic/anoxic interface within the SBB, there is an increase in the d15N of water column nitrate, as would be expected from denitrification. However, given the size of the nitrate deficit, the increase of d15N of nitrate is much smaller than would be expected from the accepted intrinsic isotope effect of denitrification of 20-30 per mil, assuming a Rayleigh model for uptake. In situations where both transport and removal are important, the Rayleigh model provides only an approximation of the actual fractionation. However, model calculations suggest that transport within the water column cannot explain the observed d15N discrepancy in the SBB. Benthic lander studies of Puget Sound sediments have demonstrated that the isotope effect of sedimentary denitrification is negligible, due to the effects of substrate diffusion in sediment porewaters (Brandes and Devol, 1997). We present new porewater measurements from the Carolina slope in the North Atlantic that confirm this conclusion for other sedimentary environments. Thus, we infer that the small magnitude of the isotopic enrichment of SBB water column nitrate is due to the importance of denitrification in the sediments relative to the water column. Assuming that water column and sedimentary denitrification have isotope effects of 25 and 0 per mil, respectively, model calculations indicate that sedimentary denitrification accounts for more than 75% of the nitrate loss within the anoxic Santa Barbara Basin.

  2. Sedimentary Rocks and Dunes

    NASA Technical Reports Server (NTRS)

    2004-01-01

    25 November 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows buttes composed of light-toned, sedimentary rock exposed by erosion within a crater occurring immediately west of Schiaparelli Basin near 4.0oS, 347.9oW. Surrounding these buttes is a field of dark sand dunes and lighter-toned, very large windblown ripples. The sedimentary rocks might indicate that the crater interior was once the site of a lake. The image covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  3. Geochemical and detrital mode evidence for two sources of Early Proterozoic sedimentary rocks from the Tonto Basin Supergroup, central Arizona

    NASA Astrophysics Data System (ADS)

    Condie, Kent C.; Noll, Phillip D.; Conway, Clay M.

    1992-04-01

    The Tonto Basin Supergroup includes up to 6.5 km of Early Proterozoic sedimentary and volcanic rocks that were deposited in a relatively short period of time at about 1.7 Ga in central Arizona. Moderate correlations of rare earth elements (REE) and Ti with Al 2O 3 and REE distributions in detrital sediments of this supergroup suggest that these elements are contained chiefly in clay-mica and/or zircon fractions. REE distributions, including negative Eu anomalies in most Tonto Basin sediments, are similar to those in Phanerozoic shales. Weak to moderate correlations of Fe, Sc, Ni, and Co to Al 2O 3 also suggest a clay-mica control of these elements. Detrital modes and geochemical characteristics of sediments indicate two dominant sources for sedimentary rocks of the Tonto Basin Supergroup: a granitoid source and a volcanic source. The granitoid source was important during deposition of the upper part of the succession (the Mazatzal Group) as shown by increases in K 2O, Al 2O 3, and Th in pelites with stratigraphic height, and increases in Zr and Hf and decreases in Eu/Eu ∗, Cr, and Ni in in pelites of the Maverick Shale. Sediment provenance characteristics and paleocurrent indicators are consistent with deposition of the supergroup in a continental-margin back-arc basin. The granitoid sediment source appears to have been the North American craton on the north, and the volcanic source a more local source from an arc on the south.

  4. Geochemical and detrital mode evidence for two sources of Early Proterozoic sedimentary rocks from the Tonto Basin Supergroup, central Arizona

    USGS Publications Warehouse

    Condie, K.C.; Noll, P.D.; Conway, C.M.

    1992-01-01

    The Tonto Basin Supergroup includes up to 6.5 km of Early Proterozoic sedimentary and volcanic rocks that were deposited in a relatively short period of time at about 1.7 Ga in central Arizona. Moderate correlations of rare earth elements (REE) and Ti with Al2O3 and REE distributions in detrital sediments of this supergroup suggest that these elements are contained chiefly in clay-mica and/or zircon fractions. REE distributions, including negative Eu anomalies in most Tonto Basin sediments, are similar to those in Phanerozoic shales. Weak to moderate correlations of Fe, Sc, Ni, and Co to Al2O3 also suggest a clay-mica control of these elements. Detrital modes and geochemical characteristics of sediments indicate two dominant sources for sedimentary rocks of the Tonto Basin Supergroup: a granitoid source and a volcanic source. The granitoid source was important during deposition of the upper part of the succession (the Mazatzal Group) as shown by increases in K2O, Al2O3, and Th in pelites with stratigraphic height, and increases in Zr and Hf and decreases in Eu/Eu*, Cr, and Ni in in pelites of the Maverick Shale. Sediment provenance characteristics and paleocurrent indicators are consistent with deposition of the supergroup in a continental-margin back-arc basin. The granitoid sediment source appears to have been the North American craton on the north, and the volcanic source a more local source from an arc on the south. ?? 1992.

  5. Petroleum system modeling of the western Canada sedimentary basin - isopach grid files

    USGS Publications Warehouse

    Higley, Debra K.; Henry, Mitchell E.; Roberts, Laura N.R.

    2005-01-01

    This publication contains zmap-format grid files of isopach intervals that represent strata associated with Devonian to Holocene petroleum systems of the Western Canada Sedimentary Basin (WCSB) of Alberta, British Columbia, and Saskatchewan, Canada. Also included is one grid file that represents elevations relative to sea level of the top of the Lower Cretaceous Mannville Group. Vertical and lateral scales are in meters. The age range represented by the stratigraphic intervals comprising the grid files is 373 million years ago (Ma) to present day. File names, age ranges, formation intervals, and primary petroleum system elements are listed in table 1. Metadata associated with this publication includes information on the study area and the zmap-format files. The digital files listed in table 1 were compiled as part of the Petroleum Processes Research Project being conducted by the Central Energy Resources Team of the U.S. Geological Survey, which focuses on modeling petroleum generation, 3 migration, and accumulation through time for petroleum systems of the WCSB. Primary purposes of the WCSB study are to Construct the 1-D/2-D/3-D petroleum system models of the WCSB. Actual boundaries of the study area are documented within the metadata; excluded are northern Alberta and eastern Saskatchewan, but fringing areas of the United States are included.Publish results of the research and the grid files generated for use in the 3-D model of the WCSB.Evaluate the use of petroleum system modeling in assessing undiscovered oil and gas resources for geologic provinces across the World.

  6. Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

    NASA Astrophysics Data System (ADS)

    Lenhardt, Nils; Götz, Annette E.

    2015-04-01

    The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

  7. A Framework to Estimate CO2 Leakage associated with Geological Storage in Mature Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    Celia, M. A.; Bachu, S.; Gasda, S.

    2002-12-01

    Geological storage of carbon dioxide requires careful risk analysis to avoid unintended consequences associated with the subsurface injection. Most negative consequences of subsurface injection are associated with leakage of the injected CO2 out of the geological formation into which it is injected. Such leakage may occur through natural geological features, including fractures and faults, or it may occur through human-created pathways such as existing wells. Possible leakage of CO2 through existing wells appears to be especially important in mature sedimentary basins that have been explored intensively and exploited for hydrocarbon production. In the Alberta Basin of western Canada, more than 300,000 oil and gas wells have been drilled, while in the state of Texas in the United States, more than 1,500,000 wells have been drilled. Many of these wells have been abandoned, and the information available to describe their current state is highly variable and sometimes nonexistent. Because these wells represent possible direct conduits from the injection zone to the land surface, a comprehensive assessment of leakage potential associated with these wells needs to be pursued. Analysis of leakage potential associated with existing wells must combine a data mining component with a multi-level modeling effort to assess leakage potential in a probabilistic framework. Information available for existing wells must be categorized and analyzed, and general leakage characteristics associated with wells of varying properties must be quantified. One example of a realistic target formation is the Viking Formation in Alberta, which is overlain by a thick shale layer and contains hydrocarbon in some locations. The existence of hydrocarbon in the formation indicates that the overlying shale layer is an effective barrier to flow, and therefore this is a good candidate formation for CO2 storage. However, the formation and its cap rock are punctured by approximately 180,000 wells, with

  8. Provenance change from the Middle to Late Triassic of the southwestern Sichuan basin, Southwest China: Constraints from the sedimentary record and its tectonic significance

    NASA Astrophysics Data System (ADS)

    Zhu, Min; Chen, Hanlin; Zhou, Jing; Yang, Shufeng

    2017-03-01

    The formation of the Sanjiang and Qinling orogens caused by closure of Paleo-Tethys Ocean along the western and northern margins of the Yangtze block during the early Mesozoic created a unique basin-mountain system. Petrology, geochemistry, geochronology, sedimentary facies and paleocurrent data are integrated in order to investigate the changing provenance of Middle-Late Triassic successions from the southwestern Sichuan region, SW China. The detrital compositions from the Middle Triassic successions indicate low mature sediments of mafic and intermediate rocks origin, which derivation mainly from recycled orogenic and secondarily from the Emeishan Large Igneous Province (ELIP). The detrital zircon U-Pb age distribution pattern of the Middle Triassic sandstone samples exhibits four major age Groups at 257 Ma, 650-500 Ma, 880-710 Ma, and 1000-900 Ma. Combined with the geochemical characteristics, an interior Yangtze block source including the Khamdian uplift and ELIP is suggested. The Late Triassic sedimentary rocks yield seven U-Pb age Groups at 245-210 Ma, 290-260 Ma, 460-410 Ma, 650 Ma, 880-710 Ma, 1900-1600 Ma, and 2600-2400 Ma, which are consistent with the data reported from the Sichuan basin, Songpan Ganzi basin and the southern Yidun terrane, and are partly similar to those of the south Qinling orogen, Jiangnan Xuefeng thrust belt. In contrast to the Middle Triassic successions, the sandstone composition modals and whole-rock geochemistry of the Late Triassic samples denote mature deposits and of intermediate and acid rocks origin. Therefore, during the Late Triassic, the southwestern Sichuan basin received materials from the Songpan Ganzi folded belt and Yidun arc complex dominantly, and from the Qinling orogen and Jiangnan Xuefeng thrust belt subsidiarily. The Sanjiang orogen and the Songpan Ganzi folded belt should have controlled the formation of the southwestern Sichuan basin, while the development of the Qinling orogen and the western Jiangnan

  9. Extensional deformation of the Guadalquivir Basin: rate of WSW-ward tectonic displacement from Upper Tortonian sedimentary rocks

    NASA Astrophysics Data System (ADS)

    Roldán, Francisco J.; Azañón, Jose Miguel; Rodríguez-Fernández, Jose; María Mateos, Rosa

    2016-04-01

    The Guadalquivir Basin (Upper Tortonian-Quaternary sedimentary infilling) has been considered the foreland basin of the Betic Orogen built up during its collision with the Sudiberian margin. The basin is currently restricted to its westernmost sector, in the Cadiz Gulf, because the Neogene-Quaternary uplift of the Betic Cordillera has produced the emersion of their central and eastern parts. The upper Tortonian chronostratigraphic unit is the oldest one and it was indistinctly deposited on the South Iberian paleomargin and the External units from the Betic Cordillera. However, these rocks are undeformed on the Sudiberian paleomargin while they are deeply affected by brittle deformation on the External Betic Zone. Outcrops of Upper Tortonian sedimentary rocks on External Betic Zone are severely fragmented showing allocthonous characters with regard to those located on the Sudiberian paleomargin. This post- Upper Tortonian deformation is not well known in the External Zones of the Cordillera where the most prominent feature is the ubiquity of a highly deformed tecto-sedimentary unit outcropping at the basement of the Guadalquivir sedimentary infilling. This tecto-sedimentary unit belongs to the Mass Wasting Extensional Complex (Rodríguez-Fernández, 2014) formed during the collision and westward migration of the Internal Zone of the Betic Cordillera (15-8,5 Ma). In the present work, we show an ensemble of tectonic, geophysical and cartographic data in order to characterize the post-Upper Tortonian deformation. For this, seismic reflection profiles have been interpreted with the help of hidrocarbon boreholes to define the thickness of the Upper Tortonian sedimentary sequence. All these data provide an estimation of the geometrical and kinematic characteristics of the extensional faults, direction of movement and rate of displacement of these rocks during Messinian/Pliocene times. References Rodríguez-Fernández, J., Roldan, F. J., J.M. Azañón y Garcia-Cortes, A

  10. Application of particle swarm optimization for gravity inversion of 2.5-D sedimentary basins using variable density contrast

    NASA Astrophysics Data System (ADS)

    Kishore Singh, Kunal; Singh, Upendra Kumar

    2017-04-01

    Particle swarm optimization (PSO) is a global optimization technique that works similarly to swarms of birds searching for food. A MATLAB code in the PSO algorithm has been developed to estimate the depth to the bottom of a 2.5-D sedimentary basin and coefficients of regional background from observed gravity anomalies. The density contrast within the source is assumed to vary parabolically with depth. Initially, the PSO algorithm is applied on synthetic data with and without some Gaussian noise, and its validity is tested by calculating the depth of the Gediz Graben, western Anatolia, and the Godavari sub-basin, India. The Gediz Graben consists of Neogen sediments, and the metamorphic complex forms the basement of the graben. A thick uninterrupted sequence of Permian-Triassic and partly Jurassic and Cretaceous sediments forms the Godavari sub-basin. The PSO results are better correlated with results obtained by the Marquardt method and borehole information.

  11. [Mass and energy transport in the earth`s crust: Hydrodynamics of sedimentary basins]. Annual report, 1994

    SciTech Connect

    1994-12-31

    The objective of this study is to investigate the cause(s) of abnormally high pore fluid pressures in the Uinta Basin, Utah. The Altamont-Bluebell oil-field, in the deepest part of the Uinta Basin, has pore pressure that in some places exceeds 0.8 of lithostatic. There are two prevailing explanations for the high pore pressure: (1) sedimentary loading and (2) the volume expansion and collapse of porosity associated with the conversion of solid kerogen to liquid oil. The purpose of this research is to test these hypotheses of pressure generation using three-dimensional, multiphase numerical simulation. These simulations will allow the authors to further investigate the migration of oil within the Uinta Basin.

  12. Tectonic and sedimentary evolution of the Ili Basin (northern Tien Shan, Kazakhstan)

    NASA Astrophysics Data System (ADS)

    Kley, J.; Voigt, T.; Seib, N.; Kober, M.

    2010-12-01

    The Tien Shan active intraplate orogen of Central Asia exhibits strong along-strike variations in structure. Its northern front in southeastern Kazakhstan is characterized by a fragmented array of anticlinal basement highs whose wavelengths range from c. 5 to 30 km. Range-bounding faults are mostly E- to ENE-trending thrust or reverse faults and SE-trending dextral strike-slip faults. Faults of large displacement (more than several tens of meters) are conspicuously absent. The synclinal lows between the basement highs preserve Cenozoic strata of Oligocene to Quaternary age, probably deposited in a once continuous basin (the Ili Basin) and recording the entire history of Tien Shan uplift. Very gentle, long-wavelength folds affect the Cenozoic strata. As far as visible, the basement is always folded conformably. The basin fill starts in the middle Oligocene (mammal fossils; Indricotherium horizon). The facies of these oldest deposits is characterized by fluvial deposits of a large river system and varying flood-plain deposits with intense soil formation (calcretes and gypsisols). Transport directions and quartz content of the sediments suggest they were not sourced from the nearby mountain ranges present today. The fluvial succession is followed by late Oligocene to early Miocene lake deposits which reflect the transition from an evaporitic lake/playa system to freshwater lacustrine conditions. The Oligocene to Early Miocene deposits are limited to a small area in the core of the Aktau anticline and show no relationship to the sediment succession overlying the basement in the uplifts surrounding the Aktau mountains in the north and west. There, alluvial and fluvial deposits of middle Miocene(?) age rest on deeply weathered paleosurfaces. Transport is mainly to the south. Changes in colour, grain size and ratio of channel to interchannel deposits probably reflect climatic changes. Rapid facies and thickness-changes allow the reconstruction of several alluvial fans

  13. Tectonics vs. Climate efficiency in triggering detrital input in sedimentary basins: the Po Plain-Venetian-Adriatic Foreland Basin (Northern Italy)

    NASA Astrophysics Data System (ADS)

    Amadori, Chiara; Di Giulio, Andrea; Toscani, Giovanni; Lombardi, Stefano; Milanesi, Riccardo; Panara, Yuri; Fantoni, Roberto

    2017-04-01

    The relative efficiency of tectonics respect to climate in triggering erosion of mountain belts is a classical but still open debate in geosciences. The fact that data both from tectonically active and inactive mountain regions in different latitudes, record a worldwide increase of sediment input to sedimentary basins during the last million years concomitantly with the cooling of global climate and its evolution toward the modern high amplitude oscillating conditions pushed some authors to conclude that Pliocene-Pleistocene climate has been more efficient than tectonics in triggering mountain erosion. Po Plain-Venetian-Adriatic Foreland System, made by the relatively independent Po Plain-Northern Adriatic Basin and Venetian-Friulian Basin, provides an ideal case of study to test this hypothesis and possibly quantify the difference between the efficiency of the two. In fact it is a relatively closed basin (i.e. without significant sediment escape) with a fairly continuous sedimentation (i.e. with a quite continuous sedimentary record) completely surrounded by collisional belts (Alps, Northern Apennines and Dinarides) that experienced only very weak tectonic activity since Calabrian time, i.e. when climate cooling and cyclicity increased the most. We present a quantitative reconstruction of the sediment flow delivered from the surrounding mountain belts to the different part of the basin during Pliocene-Pleistocene time. This flow was obtained through the 3D reconstruction of the Venetian-Friulian and Po Plain Northern Adriatic Basins architecture, performed by means of the seismic-based interpretation and time-to-depth conversion of six chronologically constrained surfaces (seismic and well log data from courtesy of ENI); moreover, a 3D decompaction of the sediment volume bounded by each couple of surfaces has been included in the workflow, in order to avoid compaction-related bias. The obtained results show in both Basins a rapid four-folds increase of the

  14. Tectono-sedimentary evolution of an extensional basin revealed by a combined photo-geological and field-mapping approach. The Montefalco Basin (Northern Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Bucci, Francesco; Mirabella, Francesco; Santangelo, Michele; Cardinali, Mauro; Guzzetti, Fausto

    2016-04-01

    Active extensional basins are important since their sedimentary infills and bounding tectonic structures provide: i) sinks with preservation potential for sedimentary and fossil records of past changes in climate and sediment/water supply, ii) information on the growth, activity, decay and death of normal faults, iii) vast economic reserves of hydrocarbons, water and minerals. Unfortunately, quaternary extensional basins, especially if located in humid and temperate climate environments, are often characterized by extensively cultivated areas, homogeneous terrains and quite flat morphologies. Furthermore, they commonly host human settlements, together with roads, economic and industrial infrastructures, with a consequent limited availability of good outcrops. Such a limitation can (often severely) hamper an adequate mapping of the sedimentary infill. Therefore alternative methodological approaches (such as aerial photographs interpretation, API) are needed to integrate heterogeneous and incomplete datasets. This contribution presents an updated photo-geological map of a Quaternary extensional basin in Central Italy, the Montefalco Basin. This basin developed in a continental environment characterized by clayey-sandy lacustrine and fluvial sequences (late Pliocene - early Pleistocene) underlying more recent coarse grained deposits related to alluvial fan environment (early-to-late Pleistocene) and younger palustrine deposits (late Pleistocene). Since the late Pleistocene, regional uplift and local tectonics led to the end of deposition in the Montefalco basin, which experienced a diffuse incision and the modification of the drainage network, in response to the W-to-E migration of active faulting and tectonic subsidence. The new photo-geological map represents an important improvement compared to the existing data, since it provides unprecedented and spatially distributed information on the geometry of the continental deposits and on the tectonic structures affecting

  15. A regional view of urban sedimentary basins in Northern California based on oil industry compressional-wave velocity and density logs

    USGS Publications Warehouse

    Brocher, T.M.

    2005-01-01

    Compressional-wave (sonic) and density logs from 119 oil test wells provide knowledge of the physical properties and impedance contrasts within urban sedimentary basins in northern California, which is needed to better understand basin amplification. These wire-line logs provide estimates of sonic velocities and densities for primarily Upper Cretaceous to Pliocene clastic rocks between 0.1 - and 5.6-km depth to an average depth of 1.8 km. Regional differences in the sonic velocities and densities in these basins largely 1reflect variations in the lithology, depth of burial, porosity, and grain size of the strata, but not necessarily formation age. For example, Miocene basin filling strata west of the Calaveras Fault exhibit higher sonic velocities and densities than older but finer-grained and/or higher-porosity rocks of the Upper Cretaceous Great Valley Sequence. As another example, hard Eocene sandstones west of the San Andreas Fault have much higher impedances than Eocene strata, mainly higher-porosity sandstones and shales, located to the east of this fault, and approach those expected for Franciscan Complex basement rocks. Basement penetrations define large impedence contrasts at the sediment/basement contact along the margins of several basins, where Quaternary, Pliocene, and even Miocene deposits directly overlie Franciscan or Salinian basement rocks at depths as much as 1.7 km. In contrast, in the deepest, geographic centers of the basins, such logs exhibit only a modest impedance contrast at the sediment/basement contact at depths exceeding 2 km. Prominent (up to 1 km/sec) and thick (up to several hundred meters) velocity and density reversals in the logs refute the common assumption that velocities and densities increase monotonically with depth.

  16. Thickness detection of sedimentary basin by P-to-S-phases of earthquake recordings at Ibaraki-ken, Japan

    NASA Astrophysics Data System (ADS)

    Hao, K.; Fujiwara, H.

    2007-12-01

    The Kanto sedimentary basin has very complicated geological formations with various sedimentary layers. The thickness of sedimentary basins varies irregularly from zeros to over several thousand meters down to the pre- Neogene bedrock. Therefore, the understanding the thickness is the fundamental in order to study the seismic ground motions. The vertical seismic profile (VSP) method may give a high-resolution seismic image at a borehole in both of P and S wave information. However, VSP is only limited to a few areas since it is too costly to be widely used. A dozen of deep-wells down to 2000 meters with VSP in the Kanto area have been drilled over past 15 years by NIED. In order to extend the high-quality VSP results farthest, we utilize these VSP data to obtain regression functions for sedimentary depth against the travel time difference of direct P and the direct S waves. On the other hands, the travel time difference between the direct P and the converted PS waves may be detected from P-to-S converted phases by means of all-pass function deconvolved from Receiver Functions (APRF) (Izumi et.al., 1990, Satoh, 2005, Hao, et.al., 2005, 2006). Comparing the classic receiver function for detection of interfaces with abrupt velocity changes in the earth crust, this APRF method can identify P-to-S phase in the near- surface interfaces much clearly, even for a high frequency of 10Hz. We use APRF with the VSP regression functions to estimate the thickness of sedimentary basin beneath each ground motion station. The objective area in this paper is whole of Prefecture Ibaraki-ken, which is located at north-east part of Kanto basin. The northern and northwestern of Ibaraki-ken are mountain areas, and Mt. Tsukuba and Lake kasumigaura are located in the center. A total of 112 strong motion stations, in which 84 stations from Sk-net, 19 K-net, and 14 KiK-net, have been targeted to study the underground structure beneath each station. Over 3000x3 records have been visually

  17. Schiaparelli's Sedimentary Rocks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    9 October 2004 Schiaparelli Basin is a large, 470 kilometer (292 miles) impact crater located east of Sinus Meridiani. The basin might once have been the site of a large lake--that is, if the sedimentary rocks exposed on its northwestern floor were deposited in water. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a 1.5 meter per pixel (5 ft per pixel) view of some of the light-toned, finely-bedded sedimentary rocks in northwestern Schiaparelli. The image is located near 1.0oS, 346.0oW, and covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the left.

  18. EGS in sedimentary basins: sensitivity of early-flowback tracer signals to induced-fracture parameters

    NASA Astrophysics Data System (ADS)

    Karmakar, Shyamal; Ghergut, Julia; Sauter, Martin

    2015-04-01

    -effective aperture, in a water fracture (WF), or - fracture thickness and porosity, for a gel-proppant fracture (GPF). We find that parameter determination from SW early signals can significantly be improved by concomitantly using a number of solute tracers with different transport and retardation behaviour. We considered tracers of different sorptivity to proppant coatings, and to matrix rock surfaces, for GPF, as well as contrasting-diffusivity or -sorptivity tracers, for WF. An advantage of this SW approach is that it requires only small chaser volumes (few times the fracture volume), not relying on advective penetration into the rock matrix. Thus, selected tracer species are to be injected during the very last stage of the fracturing process, when fracture sizes and thus target parameters are supposed to attain more or less stable values. We illustrate the application of these tracer test design principles using hydro- and lithostratigraphy data from the Geothermal Research Platform at Groß Schönebeck [4], targeting a multi-layer reservoir (sedimentary and crystalline formations in 4-5 km depth) in the NE-German Sedimentary Basin. Acknowledgments: This work benefited from long-term support from Baker Hughes (Celle) and from the Lower-Saxonian Science and Culture Ministry (MWK Niedersachsen) within the applied research project gebo (Geothermal Energy and High-Performance Drilling, 2009-2014). The first author gratefully acknowledges continued financial support from the DAAD (German Academic Exchange Service) to pursuing Ph. D. work. References: [1] http://www.sciencedirect.com/science/article/pii/S1876610214017391 [2] http://www.geothermal-energy.org/cpdb/record_detail.php?id=7215 [3] http://www.geothermal-energy.org/cpdb/record_detail.php?id=19034 [4] http://www.gfz-potsdam.de/en/scientific-services/laboratories/gross-schoenebeck/

  19. Constraints on the history and topography of the Northeastern Sierra Nevada from a Neogene sedimentary basin in the Reno-Verdi area, Western Nevada

    USGS Publications Warehouse

    Trexler, James; Cashman, Patricia; Cosca, Michael

    2012-01-01

    Neogene (Miocene–Pliocene) sedimentary rocks of the northeastern Sierra Nevada were deposited in small basins that formed in response to volcanic and tectonic activity along the eastern margin of the Sierra. These strata record an early phase (ca. 11–10 Ma) of extension and rapid sedimentation of boulder conglomerates and debrites deposited on alluvial fans, followed by fluvio-lacustrine sedimentation and nearby volcanic arc activity but tectonic quiescence, until ~ 2.6 Ma. The fossil record in these rocks documents a warmer, wetter climate featuring large mammals and lacking the Sierran orographic rain shadow that dominates climate today on the eastern edge of the Sierra. This record of a general lack of paleo-relief across the eastern margin of the Sierra Nevada is consistent with evidence presented elsewhere that there was not a significant topographic barrier between the Pacific Ocean and the interior of the continent east of the Sierra before ~ 2.6 Ma. However, these sediments do not record an integrated drainage system either to the east into the Great Basin like the modern Truckee River, or to the west across the Sierra like the ancestral Feather and Yuba rivers. The Neogene Reno-Verdi basin was one of several, scattered endorheic (i.e., internally drained) basins occupying this part of the Cascade intra-arc and back-arc area.

  20. Sedimentary budgets of the Tanzania coastal basin and implications for uplift history of the East African rift system

    NASA Astrophysics Data System (ADS)

    Said, Aymen; Moder, Christoph; Clark, Stuart; Abdelmalak, Mohamed Mansour

    2015-11-01

    Data from 23 wells were used to quantify the sedimentary budgets in the Tanzania coastal basin in order to unravel the uplift chronology of the sourcing area located in the East African Rift System. We quantified the siliciclastic sedimentary volumes preserved in the Tanzania coastal basin corrected for compaction and in situ (e.g., carbonates) production. We found that the drainage areas, which supplied sediments to this basin, were eroded in four episodes: (1) during the middle Jurassic, (2) during the Campanian-Palaeocene, (3) during the middle Eocene and (4) during the Miocene. Three of these high erosion and sedimentation periods are more likely related to uplift events in the East African Rift System and earlier rift shoulders and plume uplifts. Indeed, rapid cooling in the rift system and high denudation rates in the sediment source area are coeval with these recorded pulses. However, the middle Eocene pulse was synchronous with a fall in the sea level, a climatic change and slow cooling of the rift flanks and thus seems more likely due to climatic and eustatic variations. We show that the rift shoulders of the East African rift system have inherited their present relief from at least three epeirogenic uplift pulses of middle Jurassic, Campanian-Palaeocene, and Miocene ages.

  1. Dating the Barremian-Aptian shallow platform deposits at the eastern part of the Kopet Dagh sedimentary basin, NE Iran

    NASA Astrophysics Data System (ADS)

    Chenarani, Atefeh; Hosseini, Seyedabolfazl; Vahidi Nia, Mohammad

    2016-04-01

    The Kopet Dagh sedimentary basin covers the northeastern part of Iran, most parts of Turkmenistan and north of Afghanistan which contains several giant gas fields. The extension of this basin in the Iranian part is around 55km2(Afshar Harb, 1994). The Kopet Dagh basin is marked by having very thick sedimentary rocks and lack of volcanic activity. During the Lower Cretaceous, the Tirgan Formation was deposited in a shallow platform setting and lithologically includes in thick-bedded orbitolinid limestones. This study focuses on the biostratigraphy and age determination of these shallow-water deposits using benthic foraminifera and calcareous green algae. In the studied outcrop, the Tirgan Formation has a thickness of 180 m and includes in limestone beds with some marly intervals. It is overlain by the Sarcheshmeh Formation and rests on the Shurijeh Formation. Both contacts are believed to be transitional and lack of discontinuity. A total of 56 thin-sections were used in this study. This study led to determine 28 genera and 14 species of benthic foraminifera along with 13 genera and 5 species of calcareous green algae. Based on the obtained biostratigraphy data, a late Barremian-early Aptian age is suggested for these deposits. We also defined the precise boundary between the Barremian and Aptian which is reported for the first time from this area. Keywords: Barremian-Aptian, Shallow platform, Kopet Dagh, Iran. Reference: Afshar Harb, A., 1994. Geology of Iran: Geology of the Kopet Dagh. Geological survey of Iran, Report No. 11, 275 pp.

  2. On the formation of ultra-thick sedimentary basins on rifted margins: a comparison of the Scotian and Labrador margins

    NASA Astrophysics Data System (ADS)

    Louden, K.; Funck, T.

    2003-12-01

    Sedimentary basins that form on rifted continental margins exhibit a great variety of shapes and sizes. In particular, the total sediment thickness can vary significantly and in certain sub-basins can approach 15-20 km. The deeper structure of these ultra-thick basins is typically not well resolved by seismic reflection profiles due to poor penetration within the thickest parts of the basin. Wide-angle seismic reflection/refraction profiles can help resolve these deeper features. We compare two such sub-basins that occur on the eastern Canadian margins, where reflection and refraction profiles are able to define the complete sedimentary and crustal structures: the Sable sub-basin on the northeast Nova Scotian margin and the Hopedale sub-basin on the central Labrador margin. We compare the development of these basins by converting the sediment refraction velocities to density and back-stripping assuming local isostasy. Although these basins formed during completely different episodes of rifting on different types of continental crust, we find a surprising similarity in the characteristics of crustal thinning across each margin, especially for the lower crust. Initial thinning of the crust by 50-60% occurs within 50 km followed by more gradual thinning over the subsequent 100 km. This leaves a tongue of lower continental crust extending 150 km seaward of the unstretched continental crust. This outer region becomes the location of the thickest initial sediment deposition, followed by up-building and out-building of the shelf. The local form of this deposition differs between the two margins: with much larger syn- and immediately post-rift sediments on the Scotian margin and thicker recent deposition on the Labrador margin, probably controlled by the local availability of sediment fill. Comparison with previous models of rifting based on borehole observations for the Scotia margin compare well with the overall width of the rifting (150 km), but our results suggest more

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Application of Response Surface based Calibration and Sensitivity Analysis methods for Regional Hydrogeological Modelling in the Western Canada Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Singh, A.; Palombi, D.; Huff, G. F.

    2014-12-01

    A regional scale study of groundwater flow dynamics was undertaken in the Western Canada Sedimentary Basin (WCSB), comprising parts of Alberta, Saskatchewan and British Columbia. The objective of the study is to investigate basin-scale hydrogeology in WCSB and to establish boundary conditions for future local-scale groundwater management models. Earlier work in the Alberta basin has acknowledged the fact that in addition to topography controlled conditions, a substantial part of the basin exhibits sub-hydrostatic regimes. The basin-scale model (approx. 420,000 km2) includes Upper Cretaceous aquifers to Recent age sediments which collectively attain maximum thicknesses of >2600 m. Regional aquifer units considered for the numerical model are Quaternary sediments, and the sedimentary rocks of the Paskapoo, Scollard, Horseshoe Canyon formations and the Belly River Group. Regional aquitards delineated include the Battle and Bear Paw formations. The study area is bound to the west by the Brazeau-Waptiti thrust belt and to the south by the Canada-USA international border. The boundary to the north and east is delineated by the maximum extent of the Wapiti and Belly River groups and Judith River Formation. USGS MODFLOW was implemented for numerical simulation. The steady state numerical model was calibrated using a Response Surface based (Radial Basis Functions) optimization method. The calibration targets (~2000) were comprised of drill stem tests for deeper units and static water levels for shallower units. Petrophysical analyses of cores averaged K values from analyses of aquifer test results,and literature values were used to provide initial values and calibration ranges for hydraulic properties. Results indicate predominance of topography driven, local- to intermediate-scale flow systems in all hydrostratigraphic units with recharge of these units occurring in the foothills of the Rocky Mountains. The Battle aquitard, where present, acts to retard regional flow

  5. Multivariate indications between environment and ground water recharge in a sedimentary drainage basin in northwestern China

    NASA Astrophysics Data System (ADS)

    Zhu, Bingqi; Wang, Xunming; Rioual, Patrick

    2017-06-01

    A paucity of studies on the interaction between environment and ground water recharge severely restricts the ability of people to assess future water resources under changing environment. In this study, an effort to explore the relationship between the arid environment and ground water recharge was carried out using multivariate statistical techniques in a sedimentary drainage basin (the Jungar) in northwestern China. Hierarchical cluster analysis (HCA) and principal components analysis (PCA) were performed based on hydrogeochemical data to assess the ground water recharge and its governing factors. Observation of the HCA and PCA analytical results revealed a division of seven clusters (C1 to C7) and three principal components (PC1 to PC3), which explained 59.6%, 16.6% and 10.9% of the variance, respectively, and thus, accounted for the majority of the total variance in the original dataset. Based on these Q-mode HCA clusters and R-mode PAC scores, dominant environmental processes influencing recharge regimes were identified, i.e., geogenic, geomorphoclimatic, and anthropogenic, which separated the recharge regimes into four zones (Zone I to Zone IV). Zones I and II (C4 + C1) were associated to ;elevated hydroclimate degree; coupled to ;low salinity;. Zone III (C2 + C3) was associated to ;moderately elevated salinity; and evidently ;elevated contamination; but coupled to ;low hydroclimate degree;. Zone IV (C5 + C6 + C7) was associated mainly to ;elevated salinity; coupled to ;low or inverse hydroclimate degree;. It revealed that the geogenic processes are more significant (60%) than the geomorphoclimatic (17%) and anthropogenic (11%) processes. As a result, the overall recharge process is rather heterogeneous and is strongly environment dominated in the Jungar drainage system. Compared with other watersheds in arid environment, a distinctive feature of the Jungar waters is that they are affected by a combination of natural and non-natural events, rather than

  6. Diffusive anisotropy in low-permeability Ordovician sedimentary rocks from the Michigan Basin in southwest Ontario.

    PubMed

    Xiang, Y; Al, T; Scott, L; Loomer, D

    2013-12-01

    Diffusive anisotropy was investigated using samples from Upper Ordovician shale and argillaceous limestone from the Michigan Basin of southwest Ontario, Canada. Effective diffusion coefficients (De) were determined for iodide (I(-)) and tritiated water (HTO) tracers on paired cm-scale subsamples oriented normal (NB) and parallel to bedding (PB) prepared from preserved drill cores within one year from the date of drilling. For samples with porosity >3%, an X-ray radiography method was used with I(-) tracer for determination of De and porosity accessible to I(-) ions. A through-diffusion method with I(-) and HTO tracers was used for most siltstone and limestone samples with low-porosity (<3%). The De values range from 7.0×10(-13) to 7.7×10(-12) m(2)·s(-1) for shale, 2.1×10(-13) to 1.3×10(-12) m(2)·s(-1) for limestone, and 5.3×10(-14) to 5.6×10(-13) m(2)·s(-1) for siltstone and limestone interbeds within the Georgian Bay Formation shale. The sample-scale anisotropy ratios (De-PB:De-NB) for De values obtained using the I(-) tracer are 0.9 to 4.9, and the anisotropy ratios for the HTO tracer are in the range of 1.1 to 7.0. The influence of porosity distribution on diffusive anisotropy has been investigated using one-dimensional spatially-resolved profiles of I(-)-accessible porosity (shale only) and the use of AgNO3 for fixation of I(-) tracer in the pores, allowing for SEM visualization of I(-)-accessible pore networks. The porosity profiles at the sample scale display greatest variability in the direction normal to bedding which likely reflects sedimentary depositional processes. The SEM imaging suggests that diffusion pathways are preferentially oriented parallel to bedding in the shale and that diffusion occurs dominantly within the argillaceous component of the limestone. However, the fine clay-filled intergranular voids in the dolomitic domains of the limestone are also accessible for diffusive transport. © 2013. Published by Elsevier B.V. All rights

  7. Seepage carbonate mounds in Cenozoic sedimentary sequences from the Las Minas Basin, SE Spain

    NASA Astrophysics Data System (ADS)

    Pozo, M.; Calvo, J. P.; Scopelliti, G.; González-Acebrón, L.

    2016-04-01

    A number of carbonate mounds composed of indurate, strongly folded and/or brecciated calcite and dolomite beds occur interstratified in Cenozoic sedimentary sequences from the Las Minas Basin. Part of the fabric of the rock forming the carbonate mounds is composed of laminated to banded dolostone similar to the host rock but showing contrasted lithification. Moreover, the carbonate deposits of the mounds display aggrading neomorphism of dolomite, partial replacement of dolomite by calcite, calcite cementation, and extensive silicification, locally resulting in box-work fabric. Eight main lithofacies were distinguished in the carbonate mound deposits. In some lithofacies, chert is present as both microcrystalline to fibro-radial quartz and opal, the latter occurring mainly as cement whereas the former replace the carbonate and infill voids. Yet one of the carbonate mounds shows distinctive petrography and geochemical features thus suggesting a distinctive growth pattern. The carbon isotope compositions of calcite from the mound samples range from - 11.56 to - 5.15 δ‰ whilst dolomite is depleted in 13C, with values of - 12.38 to 3.02 δ‰. Oxygen isotopic compositions vary from - 9.42 to - 4.64 δ‰ for calcite and between - 6.68 and 8.19 δ‰ for dolomite. Carbonate in the mounds shows significant enrichment in Co, Cr, Ni and Pb content, especially in the strongly deformed (F-2-2 lithofacies) and brecciated carbonate (F-4). The carbonate deposits show depletion in REE and Y in contrast to that determined in lutite. The formation of the carbonate mounds was related to local artesian seepage thermal water flows of moderate to relative high temperatures. Pressure differences between the low permeability host rock and the circulating fluids accounted for dilational fracturing and brecciation of the host sediment packages, which combined with precipitation of new carbonate and silica mineral phases. Locally, some carbonate mounds developed where groundwater

  8. Sedimentary response to orogenic exhumation in the northern rocky mountain basin and range province, flint creek basin, west-central Montana

    USGS Publications Warehouse

    Portner, R.A.; Hendrix, M.S.; Stalker, J.C.; Miggins, D.P.; Sheriff, S.D.

    2011-01-01

    Middle Eocene through Upper Miocene sedimentary and volcanic rocks of the Flint Creek basin in western Montana accumulated during a period of significant paleoclimatic change and extension across the northern Rocky Mountain Basin and Range province. Gravity modelling, borehole data, and geologic mapping from the Flint Creek basin indicate that subsidence was focused along an extensionally reactivated Sevier thrust fault, which accommodated up to 800 m of basin fill while relaying stress between the dextral transtensional Lewis and Clark lineament to the north and the Anaconda core complex to the south. Northwesterly paleocurrent indicators, foliated metamorphic lithics, 64 Ma (40Ar/39Ar) muscovite grains, and 76 Ma (U-Pb) zircons in a ca. 27 Ma arkosic sandstone are consistent with Oligocene exhumation and erosion of the Anaconda core complex. The core complex and volcanic and magmatic rocks in its hangingwall created an important drainage divide during the Paleogene shedding detritus to the NNW and ESE. Following a major period of Early Miocene tectonism and erosion, regional drainage networks were reorganized such that paleoflow in the Flint Creek basin flowed east into an internally drained saline lake system. Renewed tectonism during Middle to Late Miocene time reestablished a west-directed drainage that is recorded by fluvial strata within a Late Miocene paleovalley. These tectonic reorganizations and associated drainage divide explain observed discrepancies in provenance studies across the province. Regional correlation of unconformities and lithofacies mapping in the Flint Creek basin suggest that localized tectonism and relative base level fluctuations controlled lithostratigraphic architecture.

  9. Constraining the Geological Time Scale for the Upper Cretaceous in the Edmonton Group: Western Canadian Sedimentary Basin

    NASA Astrophysics Data System (ADS)

    Heredia, B.; Gaylor, J. R.; Hilgen, F.; Kuiper, K.; Mezger, K.; Wijbrans, J. R.; Quidelleur, X.; Huesing, S.

    2011-12-01

    The Cretaceous period records evidence of sea-level changes, remarkably cyclic sedimentation, major perturbations in carbon cycles during anoxic events, and large scale igneous activity. Astronomically-tuned time scales are only partially consistent with recalculated Ar-Ar constraints for the Cretaceous-Paleogene (K-Pg) boundary, but differ in number and tuning of 405-kyr eccentricity related cycles. The exposures of Upper Cretaceous strata along the Red Deer River (Western Canadian Sedimentary Basin) offer a unique opportunity to examine aspects of marine, tectonic, and climatic influenced sediments. The uppermost part of the Knudsen Farm section is a well-preserved continuous section, mainly composed by climatically controlled alternations of silt and organic rich horizons, in which altered volcanic ash layers have been deposited. In this section, the K-Pg boundary has been placed at the base of a prominent coal layer (Nevis coal), approx. 24 m from the base of the c29r. We present a compilation of paleomagnetic data, chemical, colour and magnetic susceptibility proxies, and Ar-Ar, K-Ar and U-Pb (CA-TIMS) for the uppermost part of the Maastrichtian, including the base of the c29r to the K-Pg boundary and up to the lowermost Danian. High-resolution radioisotopic ages and the multi-proxy lithological and geochemical datasets are used to develop a cyclostratigraphic reconstruction of this interval, thus permitting the synchronisation of rock clocks close to the K-Pg boundary. This research is funded by the European Community's Seventh Framework Program (FP7/2007-2013) under grant agreement no [215458].

  10. Basin-Scale nd Isotope Gradients in South Atlantic Marine Sedimentary Records

    NASA Astrophysics Data System (ADS)

    Ran, W.; Abouchami, W.; Zahn, R.; Masque, P.

    2012-12-01

    radiogenic ɛNd values, whereas variable Holocene Pa/Th are combined to less radiogenic ɛNd values. The radiogenic seawater Nd isotope signature is entirely consistent with a predominance at the site during the LGM of a water body different from present-day NADW (ɛNd=-13). Together with existing Nd isotope records [3, 4, 5] this demonstrates the existence of a basin scale North-South Nd isotope gradient consistent with the contention, previously drawn from meridional 231Pa/230Th offsets [1], of a more prominent northward advection of southern component water. The combined 231Pa/230Th - Nd isotope systematics of existing marine sedimentary records has important implication for the significance and interpretation of these proxies as tracers of the dynamics of the Atlantic MOC which will be discussed in view of existing models. [1] Negre et al., Nature, 2010, 468, 84-88. [2] Galer et al., Mineral. Mag., 2011, 75, 883. [3] Rutberg et al., Nature, 2000, 405, 935-938. [4] Piotrowski et al., 2005, Science, 307: 1933-1938. [5] Roberts et al., 2010, Science, 327: 75-77.

  11. Capability of ERTS-1 imagery to investigate geological and structural features in a sedimentary basin (Bassin Parisien, France)

    NASA Technical Reports Server (NTRS)

    Cavelier, C.; Scanvic, J. Y.; Weecksteen, G.; Zizerman, A.

    1973-01-01

    A preliminary study of the MSS imagery of a sedimentary basin whose structure is regular is reported. Crops and natural vegetation are distributed all over the site located under temperate climate. Ground data available concern plant species geology and tectonic and are correlated with results from ERTS 1 imagery. This comparison shows a good correlation. The main geological units are detected or enhanced by way of agricultural land use and/or natural vegetation. Alluvial deposits are outlined by vegetation grass land and poplar trees. Some spatial relationship of geostructures, suspected until now, are identified or extended in associating results from different spectral bands.

  12. Numerical simulations of complex temperature, burial, and erosion histories for sedimentary basins and their calibration: Examples from western Germany

    SciTech Connect

    Buker, C.; Littke, R.; Welte, D.H.

    1995-08-01

    The detailed and reliable reconstruction of the geological and thermal evolution of sedimentary basins forms the indispensable basis of any simulation of generation, migration and accumulation of hydrocarbons. For this purpose - although often not taken into account - analysing and quantifying the uplift and erosion history is as important as the subsidence and temperature history. The reconstruction of the timing of hydrocarbon generation, petroleum expulsion and migration and the changing reservoir characteristics is only possible based on such an integrated approach. Applying this technique on the Carboniferous Ruhr Basin and the Lower Saxony Basin (western Germany) by utilising 1-D and 2-D forward modeling approaches resulted in important and new quantitative information on their temperature, subsidence and erosion histories which are of fundamental geological interest. The basin evolution models were calibrated using vitrinite reflectance data, fluid inclusion temperatures, and apatite and zircon fission track data. The detailed knowledge of the geological and thermal basin evolution then allowed in combination with a new kinetic model for gas generation from coals the modeling of generation, migration and accumulation of methane from Carboniferous coal seams.

  13. Sedimentary environments and preservation biases limit sulfur isotope fractionation observed in pyrite, despite large microbial fractionations

    NASA Astrophysics Data System (ADS)

    Halevy, I.; Wing, B. A.; Wenk, C.; Guimond, C.

    2015-12-01

    Microbial S isotope fractionations close to the thermodynamic fractionation between sulfate and sulfide (~70‰) are encountered only at the slowest rates of sulfate reduction in laboratory cultures. In turn, the slowest laboratory reduction rates overlap with only the highest values of cell-specific sulfate reduction rates measured in marine sediments. This chain-of-logic implies that sulfate-reducing microbes in the marine sedimentary biosphere fractionate S isotopes at magnitudes close to the thermodynamic limit. Recent observations from sulfate-poor environments indicate that fractionations are large even at micromolar sulfate concentrations, in agreement with model predictions of near-thermodynamic S isotope fractionation at these sulfate concentrations as long as cell-specific sulfate reduction rates are low. Despite the expectation of large microbial fractionations, pyrite in both modern marine sediments and Phanerozoic sedimentary rocks records apparent fractionations ranging from 0 to more than 70‰. We suggest that the observed range of modern marine and geologic apparent fractionations recorded in pyrite does not reflect variability in intrinsic microbial behavior, but an early diagenetic modulation of large microbial fractionations, which are pinned to the thermodynamic limit by the low natural rates of sulfate reduction. With a diagenetic model developed in this study, we show that the entire range of apparent fractionations is possible with microbial fractionations at the thermodynamic limit. Apparent fractionations depend on a variety of physical parameters of the sedimentary environment like sedimentation rate, porosity, and organic matter content, most of which correlate with water depth. These findings, in combination with knowledge about the preservation potential of sediments deposited at different depths, make predictions for the observed geologic range of apparent fractionations, and ways in which it differs from the range in modern marine

  14. Sedimentary facies and sequence stratigraphy of the Asmari Formation at Chaman-Bolbol, Zagros Basin, Iran

    NASA Astrophysics Data System (ADS)

    Amirshahkarami, Mahnaz; Vaziri-Moghaddam, Hossein; Taheri, Azizolah

    2007-03-01

    The Oligocene-Miocene Asmari Formation of the Zagros Basin is a thick sequence of shallow water carbonate. In the study area, it is subdivided into 14 microfacies that are distinguished on the basis of their depositional textures, petrographic analysis and fauna. Based on the paleoecology and lithology, four distinct depositional settings can be recognized: tidal flat, lagoon, barrier, and open marine. The Asmari Formation represents sedimentation on a carbonate ramp. In the inner ramp, the most abundant lithofacies are medium grained wackestone-packstone with imperforated foraminifera. The middle ramp is represented by packstone-grainstone to floatstone with a diverse assemblage of larger foraminifera with perforate wall, red algae, bryozoa, and echinoids. The outer ramp is dominated by argillaceous wackestone characterized by planktonic foraminifera and large and flat nummulitidae and lepidocyclinidae. Three third-order depositional sequences are recognized from deepening and shallowing trends in the depositional facies, changes in cycle stacking patterns, and sequence boundary features.

  15. Modeling of Wave Propagation in the Osaka Sedimentary Basin during the 2013 Awaji Island Earthquake (Mw5.8)

    NASA Astrophysics Data System (ADS)

    Asano, K.; Sekiguchi, H.; Iwata, T.; Yoshimi, M.; Hayashida, T.; Saomoto, H.; Horikawa, H.

    2013-12-01

    The three-dimensional velocity structure model for the Osaka sedimentary basin, southwest Japan is developed and improved based on many kinds of geophysical explorations for decades (e.g., Kagawa et al., 1993; Horikawa et al., 2003; Iwata et al., 2008). Recently, our project (Sekiguchi et al., 2013) developed a new three-dimensional velocity model for strong motion prediction of the Uemachi fault earthquake in the Osaka basin considering both geophysical and geological information by adding newly obtained exploration data such as reflection surveys, microtremor surveys, and receiver function analysis (hereafter we call UMC2013 model) . On April 13, 2013, an inland earthquake of Mw5.8 occurred in Awaji Island, which is close to the southwestern boundary of the aftershock area of the 1995 Kobe earthquake. The strong ground motions are densely observed at more than 100 stations in the basin. The ground motion lasted longer than four minutes in the Osaka urban area where its bedrock depth is about 1-2 km. This long-duration ground motions are mainly due to the surface waves excited in this sedimentary basin whereas the magnitude of this earthquake is moderate and the rupture duration is expected to be less than 5 s. In this study, we modeled long-period (more than 2s) ground motions during this earthquake to check the performance of the present UMC2013 model and to obtain a better constraint on the attenuation factor of sedimentary part of the basin. The seismic wave propagation in the region including the source and the Osaka basin is modeled by the finite difference method using the staggered grid solving the elasto-dynamic equations. The domain of 90km×85km×25.5km is modeled and discretized with a grid spacing of 50 m. Since the minimum S-wave velocity of the UMC2013 model is about 250 m/s, this calculation is valid up to the period of about 1 s. The effect of attenuation is included in the form of Q(f)=Q0(T0/T) proposed by Graves (1996). A PML is implemented in

  16. Geochemistry of Neogene sedimentary rocks from Borneo Basin, Malaysia: implications on paleo-weathering, provenance and tectonic setting

    NASA Astrophysics Data System (ADS)

    Ramasmay, N.; Roy, P.; MP, J.; Rufino, L.; Franz, L. K.; Viswanathan, P. M.

    2013-05-01

    Multi-element geochemistry and mineralogy are used to characterize the chemical composition, degree of paleo-weathering, provenance and tectonic settingsof the Neogene sedimentary rocks of Borneo Basin from east Malaysia. The sedimentary rocks are classified as extremely weathered sandstones (i.e. wacke, arkose, litharenite, Fe-sandstone and quartz arenite). Higher values of both weathering indices of alteration (i.e. CIA>83 and PIA>89) suggest that the sandstones have undergone extreme chemical weathering. Absence of any feldspar in the mineralogical analysis indicates its degradation during the weathering. Except for the quartz arenite, all other sandstones are characterized by post-depositional K-metasomatism and zircon enrichment through sediment recycling. The geochemical characteristics suggest a mixed-nature provenance for the sandstones with contribution coming from both felsic and mafic igneous rocks. Enriched Cr in quartz arenite and Fe-sandstone are related to contribution from ophiolite or fractionation of Cr-bearing minerals. The inferred tectonic settings are variable and suggest a complex nature of tectonic environment in the basin.

  17. The evolution of the Danube gateway between Central and Eastern Paratethys (SE Europe): Insight from numerical modelling of the causes and effects of connectivity between basins and its expression in the sedimentary record

    NASA Astrophysics Data System (ADS)

    Leever, K. A.; Matenco, L.; Garcia-Castellanos, D.; Cloetingh, S. A. P. L.

    2011-04-01

    The Pannonian and Dacic Basins in SE Europe are presently connected by the Danube River across the South Carpathians, to which they are in a back-arc and foreland position respectively. Part of the Paratethys realm during the Neogene, open water communication between the basins was interrupted by the Late Miocene uplift of the Carpathians. Different mechanisms have been proposed for the formation of the Danube gateway: capture of the upstream lake or an upstream river or incision of an antecedent river. Estimates on its age range from Late Miocene to Quaternary. A related issue is the effect of the large Mediterranean sea level fall related to the Messinian Salinity Crisis on the Paratethys subbasins, specifically the "isolated" Pannonian Basin. In a synthetic numerical modelling study, using a pseudo-3D code integrating tectonics, surface processes and isostasy, we addressed the causes and effects of changes in connectivity between two large sedimentary basins separated by an elevated barrier. Specifically, we aimed to find the expression of connectivity events in the sedimentary record in general and the consequences for the evolution of the Pannonian-Dacic area in particular. We studied a range of parameters including the geometry and uplift rate of the barrier, downstream sea level change and lithosphere rigidity. We found that changes in connectivity are expressed in the sedimentary record through their effect on base level in the upstream basin and supply in the downstream basin. The most important factors controlling the response are the elevation difference between the basins and the upstream accommodation space at the time of reconnection. The most pronounced effect of reconnection through lake capture is predicted for a large elevation difference and limited upstream accommodation space. Downstream increase in sediment supply is dependent on the latter rather than the reconnection event itself. Of the parameters we tested, the rigidity of the lithosphere

  18. Geochemistry and origin of formation waters in the western Canada sedimentary basin-I. Stable isotopes of hydrogen and oxygen

    USGS Publications Warehouse

    Hitchon, B.; Friedman, I.

    1969-01-01

    Stable isotopes of hydrogen and oxygen, together with chemical analyses, were determined for 20 surface waters, 8 shallow potable formation waters, and 79 formation waters from oil fields and gas fields. The observed isotope ratios can be explained by mixing of surface water and diagenetically modified sea water, accompanied by a process which enriches the heavy oxygen isotope. Mass balances for deuterium and total dissolved solids in the western Canada sedimentary basin demonstrate that the present distribution of deuterium in formation waters of the basin can be derived through mixing of the diagenetically modified sea water with not more than 2.9 times as much fresh water at the same latitude, and that the movement of fresh water through the basin has redistributed the dissolved solids of the modified sea water into the observed salinity variations. Statistical analysis of the isotope data indicates that although exchange of deuterium between water and hydrogen sulphide takes place within the basin, the effect is minimized because of an insignificant mass of hydrogen sulphide compared to the mass of formation water. Conversely, exchange of oxygen isotopes between water and carbonate minerals causes a major oxygen-18 enrichment of formation waters, depending on the relative masses of water and carbonate. Qualitative evidence confirms the isotopic fractionation of deuterium on passage of water through micropores in shales. ?? 1969.

  19. Aspects of sedimentary basin evolution assessed through tectonic subsidence analysis. Example: northern Gulf of Thailand

    NASA Astrophysics Data System (ADS)

    Pigott, John D.; Sattayarak, Nares

    Tectonic subsidence and subsidence rate analyses were conducted using a forward burial technique for the Cenozoic sediments of the northern Gulf of Thailand, a region presently bounded and intersected by major strike-slip fault systems. Basins represented by the seven wells studied are the Thon Buri, Hua Hin, Chumphon, Kra, and Pattani basins. The total observed subsidence was stratigraphically calibrated using well biostratigraphy and/or regional seismic stratigraphy. Tectonic subsidence was subsequently determined assuming local Airy isostasy by correcting decompacted sediments for sediment loading and variations in paleowater depths. Statistical comparison of the observed tectonic subsidence profile versus the theoretical thermal subsidence profile reveals zero-intercept times of incipient thermal-rifting and furthermore helps differentiate times of thermal subsidence from episodes of fault-controlled mechanical subsidence. Differences in tectonic subsidence, tectonic subsidence rates, and in the zero-intercept times of thermal rifting imply the Paleogene thermal associated rifting of the northern Gulf of Thailand was neither restricted spatially nor universally synchronous among the basins, but instead both spatially and time transgressive. Although coupled thermal-mechanical subsidence played a major role in the evolution for most of these basins, in some basins, e.g. the Thon Buri and northern Kra basins, subsidence was not thermally initiated. Instead, these basins experienced relatively slow-paced sediment loaded subsidence until a sudden fault-associated acceleration commenced in the Pliocene. Additional evidence for temporal and spatial changes in local strain is demonstrated by observed asynchronous episodes of "see-saw" subsidence-uplift of the basin floors. For example, while the northern Hua Hin Basin experienced Miocene-Pliocene alternations of subsidence and uplift, portions of the Pattani Basin to the southeast underwent periods of subsidence and

  20. Short-scale variations of shear-wave splitting across the Dead Sea basin: Evidence for the effects of sedimentary fill

    NASA Astrophysics Data System (ADS)

    Kaviani, Ayoub; Rümpker, Georg; Weber, Michael; Asch, Günter

    2011-02-01

    We examine shear-wave splitting of SKS waveforms collected by a temporary array of 68 stations in the region of the Dead Sea basin. The observed splitting parameters exhibit systematic variations along a dense, EW-trending 60 km profile across the basin. The delay times vary significantly between 1.0 and 2.8 seconds with smaller values in the very center of the profile. The fast polarizations are oriented more-or-less parallel to the strike of the Dead Sea transform fault and vary between -10 and 20 degrees with respect to North. Finite-frequency waveform modeling reveals that the source-region of the small-scale lateral variations is likely located within the crust. The modeling further shows that purely isotropic velocity variations affect shear-wave splitting: To a large degree, the observed variations of splitting parameters can be explained by the sedimentary fill of the basin and its low isotropic seismic velocities, whereas the mantle is uniformly anisotropic. Our study indicates that precaution must be taken when interpreting short-scale lateral variations of shear wave splitting in terms of anisotropic structures in the crust or upper mantle.

  1. Seismic Hazard Maps for Seattle, Washington, Incorporating 3D Sedimentary Basin Effects, Nonlinear Site Response, and Rupture Directivity

    USGS Publications Warehouse

    Frankel, Arthur D.; Stephenson, William J.; Carver, David L.; Williams, Robert A.; Odum, Jack K.; Rhea, Susan

    2007-01-01

    This report presents probabilistic seismic hazard maps for Seattle, Washington, based on over 500 3D simulations of ground motions from scenario earthquakes. These maps include 3D sedimentary basin effects and rupture directivity. Nonlinear site response for soft-soil sites of fill and alluvium was also applied in the maps. The report describes the methodology for incorporating source and site dependent amplification factors into a probabilistic seismic hazard calculation. 3D simulations were conducted for the various earthquake sources that can affect Seattle: Seattle fault zone, Cascadia subduction zone, South Whidbey Island fault, and background shallow and deep earthquakes. The maps presented in this document used essentially the same set of faults and distributed-earthquake sources as in the 2002 national seismic hazard maps. The 3D velocity model utilized in the simulations was validated by modeling the amplitudes and waveforms of observed seismograms from five earthquakes in the region, including the 2001 M6.8 Nisqually earthquake. The probabilistic seismic hazard maps presented here depict 1 Hz response spectral accelerations with 10%, 5%, and 2% probabilities of exceedance in 50 years. The maps are based on determinations of seismic hazard for 7236 sites with a spacing of 280 m. The maps show that the most hazardous locations for this frequency band (around 1 Hz) are soft-soil sites (fill and alluvium) within the Seattle basin and along the inferred trace of the frontal fault of the Seattle fault zone. The next highest hazard is typically found for soft-soil sites in the Duwamish Valley south of the Seattle basin. In general, stiff-soil sites in the Seattle basin exhibit higher hazard than stiff-soil sites outside the basin. Sites with shallow bedrock outside the Seattle basin have the lowest estimated hazard for this frequency band.

  2. Assessment of the Fundamental Resonance Frequency of the Sedimentary Cover in the Eskisehir Basin (Turkey) Using Noise Measuremeets

    NASA Astrophysics Data System (ADS)

    Tün, Muammer; Karabulut, Savaş; Avdan, Uǧur; Özel, Oǧuz; Güney, Yücel

    2014-05-01

    Geological observations indicate that the Eskisehir graben is related with Eskisehir Fault Zone (EFZ), one of the major active structures within the Anatolian plate. The fault zone has a considerable seismic risk for the urban area of Eskişehir. Local site conditions substantially affect the characteristics of seismic waves and generally have a direct effect on the potential of the earthquake damage. Site effects are very complex factors. The importance of site response is well known, and few would question the assertion that the motion on soil is usually greater than on rock, when all other things were being held equal. In general, site response estimation can be obtained from instrumental recordings. The purpose of this study was to estimate if there would be a relationship between the structural geology in the Eskisehir Basin and the fundamental resonance frequency. Extensive ambient noise measurements were performed in the basin of Eskisehir from June 2010 to spring 2012. In this work, we conduct microtremor surveys to investigate the 3-D basin structure of Eskisehir Basin and determine the fundamental resonance frequency of the sedimentary cover in the Eskisehir Valley area. The measurements of single-station microtremor were carried out at 318 sites in the Eskişehir Basin. We use data recorded by a broadband seismometer and digitizer CMG-6TD, Guralp seismometer. Some of the measurement locations, the CMG-6TD sensor was located into 30 cm-deep holes in the ground to avoid strongly wind-generated, long-period noise. Finally, a map showing the fundamental resonance frequency distribution in the studied area was drawn using the results obtained from applying the HVSR technique. A fundamental resonance frequency map of the Eskisehir Basin was produced from main peak in the horizontal-to-vertical component (H/V) spectral ratio.

  3. Geodynamics of flat-slab subduction, sedimentary basin development, and hydrocarbon systems along the southern Alaska convergent plate margin

    NASA Astrophysics Data System (ADS)

    Finzel, Emily S.

    Combining field-based geologic studies and numerical modeling provides a robust tool for evaluating the geodynamics of convergent margins. Southern Alaska is arguably the most tectonically active part of the convergent margin of western North America. This conceptual approach has been used to interpret the modern basin dynamics, as well as key stages in the Cenozoic development of this region, including spreading-ridge and flat-slab subduction. New macrofossil, palynological, and lithostratigraphic data for the Bear Lake Formation in the Bristol Bay retroarc basin allow us to construct the first chronostratigraphic framework for this formation, and indicate deposition during Middle and Late Miocene time in a regional transgressive estuarine depositional system. In the Cook Inlet forearc basin, new detrital zircon U-Pb geochronology, rare earth element geochemistry, and clast compositional data from middle Eocene-Pliocene strata demonstrate the importance of sediment sources located in the retroarc region and along strike within the basin. The Yakutat microplate has recently been reinterpreted to represent buoyant crust that is presently subducting at a shallow angle beneath southern Alaska. Integration of stratigraphic, geochronologic, and thermochronologic data indicate that in the flat-slab region, exhumation initiated ca. 43 Ma and migrated inboard, magmatism ceased at ca. 32 Ma, and deposition in sedimentary basins ended by ca. 23 Ma. Sedimentary basins positioned along the western and northern perimeter of the flat-slab region record enhanced subsidence and sediment delivery from the flat-slab region beginning in late Oligocene and middle Miocene time respectively. The discrete contributions of unique driving forces for lithospheric deformation in western Canada and Alaska have not been quantified in detail, so their relative role in influencing deformation has remained unresolved. Using finite element models, we calculate a continuous strain rate and velocity

  4. Effect of surrounding fault on distributed fault of blind reverse fault in sedimentary basin - Uemachi Faults, Osaka Basin, Southwest Japan -

    NASA Astrophysics Data System (ADS)

    Inoue, N.

    2012-12-01

    Several large cities and metropolitan areas, such as Osaka and Kobe are located in the Osaka basin, which has been filled by the Pleistocene Osaka group and the later sediments. The basin is surrounded by E-W trending strike slip faults and N-S trending reverse faults. The N-S trending 42-km-long Uemachi faults traverse in the central part of the Osaka city. The various geological, geophysical surveys, such as seismic reflection, micro tremor, gravity surveys and deep boreholes, revealed the complex basement configuration along the Uemachi faults. The depth of the basement is shallow in the central part of the Osaka plain. The Uemachi faults are locates on the western side of the basement upland. In the central part of the Uemachi faults, the displacement decreases. The fault model of the Uemachi faults consists of the two parts, the north and south parts. The NE-SW trending branch faults, Suminoe and Sakuragawa flexures, are also recognized based on various surveys around the central part. Kusumoto et al. (2001) reported that surrounding faults enable to form the basement configuration without the Uemachi faults model based on a dislocation model. Inoue et al. (2011) performed various parameter studies for dislocation model and gravity changes based on simplified faults model, which were designed based on the distribution of the real faults. The model was consisted of 7 faults including the Uemachi faults. In this study, the Osaka-wan fault was considered for the dislocation model. The results show the basement configuration including NE-SW branch faults. The basement configuration differs from the subsurface structure derived from the investigation of abundance geotechnical borehole data around the central part of the Uemachi faults. The tectonic developing process including the erosion and sea level change are require to understanding the structure from the basement to the surface of the Uemachi Fault Zone. This research is partly funded by the Comprehensive

  5. Basement configuration of the West Bengal sedimentary basin, India as revealed by seismic refraction tomography: its tectonic implications

    NASA Astrophysics Data System (ADS)

    Damodara, N.; Rao, V. Vijaya; Sain, Kalachand; Prasad, Asssrs; Murty, Asn

    2017-01-01

    SUMMARYUnderstanding the <span class="hlt">sedimentary</span> thickness, structure and tectonics of the West Bengal <span class="hlt">basin</span> is attempted using pseudo 3-D configuration derived from the first arrival seismic refraction data. Velocity images of the West Bengal <span class="hlt">basin</span> are derived using traveltime tomography along four profiles. The models are assessed for their reliability through chi-squares estimates, rms residual, traveltime fit, rays traced through the models, and resolution by checkerboard tests. Tomographic images depict smooth velocity variations of Recent, Quaternary and Tertiary sediments of velocity 1.8-4.3 km/s deposited over the Rajmahal trap of 4.8 km/s velocity and the basement (5.9 km/s) down to a maximum depth of 16 km. The present study indicates a south-easterly dip of <span class="hlt">basin</span> as evidenced from the pseudo 3-D configuration. The basement depth along the seismic profiles varies from 1 km to 16 km depending on its location in the <span class="hlt">basin</span>. It is shallow in the north & west and deep in the east & south. The depth of the basement on the stable shelf of the <span class="hlt">basin</span> in the west gently increases to about 8 km and dips to a maximum depth of 16 km in the deep <span class="hlt">basin</span> part within a short distance in the east. The study identifies a regional feature, known as the Shelf break or the Hinge zone, where stable Indian shield ends and a sharp increase in sediment thickness occurs. The Hinge zone may represent the relict of continental and proto-oceanic crustal boundary formed during the rifting of India from Antarctica. The regional gravity map of the Bengal <span class="hlt">basin</span> prepared in this study clearly brings out the Hinge zone with a linear gravity high that is compatible with seismic data. Presence of Shelf break / Hinge zone and Rajmahal volcanism in the <span class="hlt">basin</span> suggests the influence of rifting of India from the combined Antarctica-Australia at ˜130 Ma due to mantle plume activity on the structure and tectonics of the West Bengal <span class="hlt">basin</span>. These features along with the elevated rift shoulder are in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoJI.208.1490D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoJI.208.1490D"><span>Basement configuration of the West Bengal <span class="hlt">sedimentary</span> <span class="hlt">basin</span>, India as revealed by seismic refraction tomography: its tectonic implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Damodara, N.; Rao, V. Vijaya; Sain, Kalachand; Prasad, A. S. S. S. R. S.; Murty, A. S. N.</p> <p>2017-03-01</p> <p>Understanding the <span class="hlt">sedimentary</span> thickness, structure and tectonics of the West Bengal <span class="hlt">basin</span> is attempted using pseudo 3-D configuration derived from the first arrival seismic refraction data. Velocity images of the West Bengal <span class="hlt">basin</span> are derived using traveltime tomography along four profiles. The models are assessed for their reliability through chi-squares estimates, rms residual, traveltime fit, rays traced through the models and resolution by checkerboard tests. Tomographic images depict smooth velocity variations of Recent, Quaternary and Tertiary sediments of velocity 1.8-4.3 km s-1 deposited over the Rajmahal trap of 4.8 km s-1 velocity and the basement (5.9 km s-1) down to a maximum depth of 16 km. The present study indicates a south-easterly dip of <span class="hlt">basin</span> as evidenced from the pseudo 3-D configuration. The basement depth along the seismic profiles varies from 1 to 16 km depending on its location in the <span class="hlt">basin</span>. It is shallow in the north & west and deep in the east & south. The depth of the basement on the stable shelf of the <span class="hlt">basin</span> in the west gently increases to about 8 km and dips to a maximum depth of 16 km in the deep <span class="hlt">basin</span> part within a short distance in the east. The study identifies a regional feature, known as the Shelf break or the Hinge zone, where stable Indian shield ends and a sharp increase in sediment thickness occurs. The Hinge zone may represent the relict of continental and proto-oceanic crustal boundary formed during the rifting of India from Antarctica. The regional gravity map of the Bengal <span class="hlt">basin</span> prepared in this study clearly brings out the Hinge zone with a linear gravity high that is compatible with seismic data. Presence of Shelf break/Hinge zone and Rajmahal volcanism in the <span class="hlt">basin</span> suggests the influence of rifting of India from the combined Antarctica-Australia at ∼130 Ma due to mantle plume activity on the structure and tectonics of the West Bengal <span class="hlt">basin</span>. These features along with the elevated rift shoulder are in agreement with the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.6222V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.6222V"><span>Reliability of poroelastic equation in determination of minimum horizontal stress in <span class="hlt">sedimentary</span> <span class="hlt">basins</span>: implication of tectonic strain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vo, Uy; Chang, Chandong</p> <p>2017-04-01</p> <p>Minimum horizontal stress (Shmin) magnitude, normally one of the three principal stresses, provides vital information in various stages of petroleum development such as hydraulic fracture design, wellbore stability analysis, and sand production prediction. Mini-frac or leak-off tests (LOT) are considered to be the technique used to measure Shmin magnitudes directly in the formation. Still, other than being time-consuming and costly, LOT does not give a continuous Shminprofile. A conventional alternative is to use a linear poroelasticity equation derived based on the assumption of uniaxially strained <span class="hlt">basins</span>, which provides minimum horizontal stress magnitude (Shmin) as a function of vertical stress, pore pressure and Poisson's ratio (ν). In this study, we inspect the reliability of poroelastic equation-based calculation by comparing measured data of Shmin, pore pressure with log-based minimum horizontal stress magnitude in 6 major <span class="hlt">sedimentary</span> <span class="hlt">basins</span> worldwide. For calculation of Shmin via the equation, we assume ν of 0.25 and Biot's constant of unity. The comparison shows that the predicted Shmin values generally underestimate the measured values by a range between 4% and as high as 29% depending on the regions. The wide variation of horizontal stress may imply unpredictable complications in the stress states in the <span class="hlt">sedimentary</span> <span class="hlt">basins</span>. Besides, we also collect the data of maximum horizontal stress magnitudes and Young's modulus to estimate local tectonic strains, which are responsible for additional stresses over the induced horizontal stresses. The result reveals that the tectonic strain magnitudes are not consistent with the difference between measured and calculated values in minimum horizontal stress. Our results suggest that rock mechanical property such as Young's modulus is a more dominant factor that controls tectonic stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H23E1439B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H23E1439B"><span>Reactive transport modeling of dissolved oxygen migration and consumption in a <span class="hlt">sedimentary</span> <span class="hlt">basins</span> affected by a deglaciation event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bea, S. A.; Mayer, K. U.; MacQuarrie, K. T.</p> <p>2012-12-01</p> <p>In intracratonic <span class="hlt">sedimentary</span> <span class="hlt">basins</span>, geochemical conditions are currently reducing at depth. Deep groundwater flow systems are driven primarily by salinity differences, topographic gradients and recharge derived from precipitation; these systems are also influenced by the hydrostratigraphy of the <span class="hlt">basin</span>. However, during periods of glacial melt water production (i.e., deglaciation events), the melting of ice sheets may alter the patterns of freshwater infiltration, potentially resulting in enhanced recharge of glacial melt water containing relatively high concentrations of dissolved oxygen. Reactive transport modeling can be used to understand the evolution of geochemical conditions and redox-buffering capacity of these formations. Dissolved oxygen will interact with reduced mineral phases that are present in the <span class="hlt">sedimentary</span> units (e.g., chlorite) or with solid organic matter causing oxygen consumption. Processes included in the model are density-driven flow and transport, vertical mechanical deformation, as well as chemical reactions (aqueous complexation, mineral dissolution and precipitation including evaporites, sulfates and carbonates, cation-exchange, redox processes involving the decomposition of organic matter, dissolution of Fe-bearing minerals, biotite and chlorite, and the oxidation of ferrous iron and sulfide). Transient boundary conditions are imposed in the upper part of the model to mimic ice sheet advance and retreat. Simulation results indicate that the presence of dense brines at depth results in low groundwater velocities during glacial meltwater infiltration, restricting the ingress of oxygenated waters in the <span class="hlt">basin</span>. In addition, due to the abundance of reduced mineral phases and solid organic matter in these formations, geochemical processes causing oxygen consumption are restricted to shallow aquifers, further limiting the ingress of oxygenated waters to the first 100 m in the main aquifers (i.e., sandstones) and 50 m in the carbonates aquifers</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeCoA.186..120R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeCoA.186..120R"><span><span class="hlt">Sedimentary</span> pyrite δ34S differs from porewater sulfide in Santa Barbara <span class="hlt">Basin</span>: Proposed role of organic sulfur</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raven, Morgan Reed; Sessions, Alex L.; Fischer, Woodward W.; Adkins, Jess F.</p> <p>2016-08-01</p> <p>Santa Barbara <span class="hlt">Basin</span> sediments host a complex network of abiotic and metabolic chemical reactions that knit together the carbon, sulfur, and iron cycles. From a 2.1-m sediment core collected in the center of the <span class="hlt">basin</span>, we present high-resolution profiles of the concentrations and isotopic compositions of all the major species in this system: sulfate, sulfide (∑H2S), elemental sulfur (S0), pyrite, extractable organic sulfur (OS), proto-kerogen S, total organic and dissolved inorganic carbon, and total and reducible iron. Below 10 cm depth, the core is characterized by low apparent sulfate reduction rates (<0.01 mM/yr) except near the sulfate-methane transition zone. Surprisingly, pyrite forming in shallow sediments is ∼30‰ more 34S-depleted than coexisting ∑H2S in porewater. S0 has the same strongly 34S-depleted composition as pyrite where it forms near the sediment-water interface, though not at depth. This pattern is not easily explained by conventional hypotheses in which <span class="hlt">sedimentary</span> pyrite derives from abiotic reactions with porewater ∑H2S or from the products of S0 disproportionation. Instead, we propose that pyrite formation in this environment occurs within sulfate reducing microbial aggregates or biofilms, where it reflects the isotopic composition of the immediate products of bacterial sulfate reduction. Porewater ∑H2S in Santa Barbara <span class="hlt">Basin</span> may be more 34S-enriched than pyrite due to equilibration with relatively 34S-enriched OS. The difference between OS and pyrite δ34S values would then reflect the balance between microbial sulfide formation and the abundance of exchangeable OS. Both OS and pyrite δ34S records thus have the potential to provide valuable information about biogeochemical cycles and redox structure in <span class="hlt">sedimentary</span> paleoenvironments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035612','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035612"><span>Middle Jurassic Topawa group, Baboquivari Mountains, south-central Arizona: Volcanic and <span class="hlt">sedimentary</span> record of deep <span class="hlt">basins</span> within the Jurassic magmatic arc</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Haxel, G.B.; Wright, J.E.; Riggs, N.R.; Tosdal, R.M.; May, D.J.</p> <p>2005-01-01</p> <p>Among supracrustal sequences of the Jurassic magmatic arc of the southwestern Cordillera, the Middle Jurassic Topawa Group, Baboquivari Mountains, south-central Arizona, is remarkable for its lithologic diversity and substantial stratigraphic thickness, ???8 km. The Topawa Group comprises four units (in order of decreasing age): (1) Ali Molina Formation-<span class="hlt">largely</span> pyroclastic rhyolite with interlayered eolian and fluvial arenite, and overlying conglomerate and sandstone; (2) Pitoikam Formation-conglomerate, <span class="hlt">sedimentary</span> breccia, and sandstone overlain by interbedded silt- stone and sandstone; (3) Mulberry Wash Formation-rhyolite lava flows, flow breccias, and mass-flow breccias, with intercalated intraformational conglomerate, <span class="hlt">sedimentary</span> breccia, and sandstone, plus sparse within-plate alkali basalt and comendite in the upper part; and (4) Tinaja Spring Porphyry-intrusive rhyolite. The Mulberry Wash alkali basalt and comendite are genetically unrelated to the dominant calcalkaline rhyolite. U-Pb isotopic analyses of zircon from volcanic and intrusive rocks indicate the Topawa Group, despite its considerable thickness, represents only several million years of Middle Jurassic time, between approximately 170 and 165 Ma. <span class="hlt">Sedimentary</span> rocks of the Topawa Group record mixing of detritus from a minimum of three sources: a dominant local source of porphyritic silicic volcanic and subvolcanic rocks, identical or similar to those of the Topawa Group itself; Meso- proterozoic or Cambrian conglomerates in central or southeast Arizona, which contributed well-rounded, highly durable, polycyclic quartzite pebbles; and eolian sand fields, related to Middle Jurassic ergs that lay to the north of the magmatic arc and are now preserved on the Colorado Plateau. As the Topawa Group evidently represents only a relatively short interval of time, it does not record long-term evolution of the Jurassic magmatic arc, but rather represents a Middle Jurassic "stratigraphic snapshot" of the arc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.8247K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.8247K"><span>Organic-geochemical characterization of <span class="hlt">sedimentary</span> organic matter deposited during the Valanginian carbon isotope excursion (Vocontian <span class="hlt">Basin</span>, SE France)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kujau, Ariane; Heimhofer, Ulrich; Ostertag-Henning, Christian; Mutterlose, Jörg; Gréselle, Benjamin</p> <p>2010-05-01</p> <p>Terrestrial and marine <span class="hlt">sedimentary</span> archives covering the Valanginian interval (136.8-133.9 Ma, Ogg et al., 2004) display a distinct positive delta13C-isotope excursion (CIE) of ~2.5 permil (Lini et al., 1992; Gröcke et al., 2005). The carbon isotope shift spans ~2.0 Ma and has been interpreted to reflect severe perturbations of the Early Cretaceous carbon cycle and paleoenvironmental conditions. According to different authors, the Valanginian CIE was accompanied by enhanced volcanic activity of the Paranà-Etendeka <span class="hlt">large</span> igneous flood basalts, enhanced pCO2 (Lini et al., 1992; Weissert et al., 1998), widespread biocalcification crisis (Erba et al., 2004) and a distinct climatic cooling as evidenced by ice-rafted debris and glendonites from high-latitude sites. In addition, the positive CIE was assigned to be the result of an anoxic event, named the Weissert OAE (Erba et al., 2004). In this study, we investigate the composition and distribution of <span class="hlt">sedimentary</span> organic matter (OM) deposited in a hemipelagic setting before, during, and after the Valanginian CIE. The aim of this study is to provide a detailed view on possible changes in OM deposition during a time of major paleoenvironmental and climatic stress. The chosen approach combines sedimentological and chemostratigraphical information (delta13Ccarb) with geochemical analysis of the bulk OM (incl. TOC, C/N, delta13Corg, Rock-Eval) and biomarker data. For this study, hemipelagic deposits located in the <span class="hlt">basinal</span> part of the Vocontian Trough (SE France) covering the late Valanginian to early Hauterivian (Campylotoxus Zone to Radiatus Zone) (Gréselle 2007) have been sampled on a high resolution (sampling spacing of ~2/m). A total of three sections has been logged (La Charce, Vergol, Morenas), which consist of hemipelagic marl-limestone alternations and which allow for the construction of a composite succession. The delta13Ccarb values range between ~0.1 and 2.7 permil and show a characteristic stratigraphic trend</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910543B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910543B"><span>Indentation of the Pamirs with respect to the northern margin of Tibet: Constraints from the Tarim <span class="hlt">basin</span> <span class="hlt">sedimentary</span> record</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blayney, Tamsin; Najman, Yani; Dupont-Nivet, Guillaume; Carter, Andy; Millar, Ian; Garzanti, Eduardo; Sobel, Ed; Rittner, Martin; Ando, Sergio; Gao, Zhaojie; Vezzoli, Giovanni</p> <p>2017-04-01</p> <p>The Pamirs represent the indented westward continuation of the northern margin of the Tibetan Plateau, dividing the Tarim and Tajik <span class="hlt">basins</span>. Their evolution may be a key factor influencing aridification of the Asian interior, yet the tectonics of the Pamir Salient are poorly understood. We present a provenance study of the Aertashi section, a Paleogene to late Neogene clastic succession deposited in the Tarim <span class="hlt">basin</span> to the north of the NW margin of Tibet (the West Kunlun) and to the east of the Pamirs. Our detrital zircon U-Pb ages coupled with zircon fission track, bulk rock Sm-Nd, and petrography data document changes in contributing source terranes during the Oligocene to Miocene, which can be correlated to regional tectonics. We propose a model for the evolution of the Pamir and West Kunlun (WKL), in which the WKL formed topography since at least 200 Ma. By 25 Ma, movement along the Pamir-bounding faults such as the Kashgar-Yecheng Transfer System had commenced, marking the onset of Pamir indentation into the Tarim-Tajik <span class="hlt">basin</span>. This is coincident with basinward expansion of the northern WKL margin, which changed the palaeodrainage pattern within the Kunlun, progressively cutting off the more southerly WKL sources from the Tarim <span class="hlt">basin</span>. An abrupt change in the provenance and facies of sediments at Aertashi has a maximum age of 14 Ma; this change records when the Pamir indenter had propagated sufficiently far north that the North Pamir was now located proximal to the Aertashi region. Reference: Blayney, T., et al. (2016), Indentation of the Pamirs with respect to the northern margin of Tibet: Constraints from the Tarim <span class="hlt">basin</span> <span class="hlt">sedimentary</span> record, Tectonics, 35, doi:10.1002/ 2016TC004222.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.204.1678A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.204.1678A"><span>Modelling of wave propagation and attenuation in the Osaka <span class="hlt">sedimentary</span> <span class="hlt">basin</span>, western Japan, during the 2013 Awaji Island earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asano, Kimiyuki; Sekiguchi, Haruko; Iwata, Tomotaka; Yoshimi, Masayuki; Hayashida, Takumi; Saomoto, Hidetaka; Horikawa, Haruo</p> <p>2016-03-01</p> <p>On 2013 April 13, an inland earthquake of Mw 5.8 occurred in Awaji Island, which forms the western boundary of the Osaka <span class="hlt">sedimentary</span> <span class="hlt">basin</span> in western Japan. The strong ground motion data were collected from more than 100 stations within the <span class="hlt">basin</span> and it was found that in the Osaka Plain, the pseudo velocity response spectra at a period of around 6.5 s were significantly larger than at other stations of similar epicentral distance outside the <span class="hlt">basin</span>. The ground motion lasted longer than 3 min in the Osaka Plain where its bedrock depth spatially varies from approximately 1 to 2 km. We modelled long-period (higher than 2 s) ground motions excited by this earthquake, using the finite difference method assuming a point source, to validate the present velocity structure model and to obtain better constraint of the attenuation factor of the <span class="hlt">sedimentary</span> part of the <span class="hlt">basin</span>. The effect of attenuation in the simulation was included in the form of Q(f) = Q0(f/f0), where Q0 at a reference frequency f0 was given by a function of the S-wave velocity, Q0 = αVS. We searched for appropriate Q0 values by changing α for a fixed value of f0 = 0.2 Hz. It was found that values of α from 0.2 to 0.5 fitted the observations reasonably well, but that the value of α = 0.3 performed best. Good agreement between the observed and simulated velocity waveforms was obtained for most stations within the Osaka <span class="hlt">Basin</span> in terms of both amplitude and ground motion duration. However, underestimation of the pseudo velocity response spectra in the period range of 5-7 s was recognized in the central part of the Osaka Plain, which was caused by the inadequate modelling of later phases or wave packets in this period range observed approximately 2 min after the direct S-wave arrival. We analysed this observed later phase and concluded that it was a Love wave originating from the direction of the east coast of Awaji Island.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4476F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4476F"><span>New approaches in the indirect quantification of thermal rock properties in <span class="hlt">sedimentary</span> <span class="hlt">basins</span>: the well-log perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuchs, Sven; Balling, Niels; Förster, Andrea</p> <p>2016-04-01</p> <p>Numerical temperature models generated for geodynamic studies as well as for geothermal energy solutions heavily depend on rock thermal properties. Best practice for the determination of those parameters is the measurement of rock samples in the laboratory. Given the necessity to enlarge databases of subsurface rock parameters beyond drill core measurements an approach for the indirect determination of these parameters is developed, for rocks as well a for geological formations. We present new and universally applicable prediction equations for thermal conductivity, thermal diffusivity and specific heat capacity in <span class="hlt">sedimentary</span> rocks derived from data provided by standard geophysical well logs. The approach is based on a data set of synthetic <span class="hlt">sedimentary</span> rocks (clastic rocks, carbonates and evaporates) composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities varying between 0 and 30%. Petrophysical properties are assigned to both the rock-forming minerals and the pore-filling fluids. Using multivariate statistics, relationships then were explored between each thermal property and well-logged petrophysical parameters (density, sonic interval transit time, hydrogen index, volume fraction of shale and photoelectric absorption index) on a regression sub set of data (70% of data) (Fuchs et al., 2015). Prediction quality was quantified on the remaining test sub set (30% of data). The combination of three to five well-log parameters results in predictions on the order of <15% for thermal conductivity and thermal diffusivity, and of <10% for specific heat capacity. Comparison of predicted and benchmark laboratory thermal conductivity from deep boreholes of the Norwegian-Danish <span class="hlt">Basin</span>, the North German <span class="hlt">Basin</span>, and the Molasse <span class="hlt">Basin</span> results in 3 to 5% larger uncertainties with regard to the test data set. With regard to temperature models, the use of calculated TC borehole profiles approximate measured temperature logs with an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1413197M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1413197M"><span>Effects of <span class="hlt">large</span> sea-level variations in connected <span class="hlt">basins</span>: the Dacian - Black Sea system of the Eastern Paratethys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Munteanu, I.; Matenco, L.; Dinu, C.; Cloetingh, S.</p> <p>2012-04-01</p> <p>Sea-level changes provide an important control on the interplay between accommodation space and sediment supply, in particular for shallow-water <span class="hlt">basins</span> where the available space is limited. Sediment exchange between connected <span class="hlt">basins</span> separated by a subaqueous sill (bathymetric threshold) is still not well understood. When sea-level falls below the bathymetric level of this separating sill, the shallow-water <span class="hlt">basin</span> evolution is controlled by its erosion and rapid fill. Once this marginal <span class="hlt">basin</span> is filled, the <span class="hlt">sedimentary</span> depocenter shifts to the open marine <span class="hlt">basin</span> (outward shift). With new accommodation space created during the subsequent sea-level rise, sediment depocenter shifts backwards to the marginal <span class="hlt">basin</span> (inward shift). This new conceptual model is tested here in the context of Late Miocene to Quaternary evolution of the open connection between Dacian and Black Sea <span class="hlt">basins</span>. By the means of seismic sequence stratigraphic analysis of the Miocene-Pliocene evolution of this Eastern Paratethys domain, this case study demonstrates these shifts in <span class="hlt">sedimentary</span> depocenter between <span class="hlt">basins</span>. An outward shift occurs with a delay that corresponds to the time required to fill the remaining accommodation space in the Dacian <span class="hlt">Basin</span> below the sill that separates it from the Black Sea. This study provides novel insight on the amplitude and <span class="hlt">sedimentary</span> geometry of the Messinian Salinity Crisis (MSC) event in the Black Sea. A <span class="hlt">large</span> (1.3 - 1.7km) sea-level drop is demonstrated by quantifying coeval sedimentation patterns that change to mass-flows and turbiditic deposits in the deep-sea part of this main sink. The post-MSC sediment routing continued into the present-day pattern of Black Sea rivers discharge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRB..121.2235W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRB..121.2235W"><span>The Cenozoic growth of the Qilian Shan in the northeastern Tibetan Plateau: A <span class="hlt">sedimentary</span> archive from the Jiuxi <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Weitao; Zhang, Peizhen; Pang, Jianzhang; Garzione, Carmala; Zhang, Huiping; Liu, Caicai; Zheng, Dewen; Zheng, Wenjun; Yu, Jingxing</p> <p>2016-04-01</p> <p><span class="hlt">Sedimentary</span> deposits in Tibetan <span class="hlt">Basins</span> archive the spatial-temporal patterns of the deformation and surface uplift processes that created the area's high topography during the Cenozoic India-Asia collision. In this study, new stratigraphic investigation of the Caogou section from the Jiuxi <span class="hlt">Basin</span> in the northeasternmost part of Tibetan Plateau provides chronologic constraints on the deformation and northward growth of the plateau. Magnetostratigraphic analysis results suggest that the age of the studied ~1000 m thick section spans from ~24.2 Ma to 2.8 Ma. Detailed sedimentology and apatite fission track (AFT) analyses reveal that variations in the clast provenance, lithofacies, sediment accumulation rates, and AFT lag times occurred at ~13.5-10.5 Ma. We interpret these changes as in response to the initial uplift of the North Qilian Shan. In addition, paleomagnetic declination results from the section indicate a clockwise rotation of the Jiuxi <span class="hlt">Basin</span> before ~13.5 Ma, which was followed by a subsequent counterclockwise rotation during 13.5-9 Ma. This reversal in rotation direction may be directly related to left-lateral strike-slip activity along the easternmost segment of the Altyn Tagh Fault. Combined with previous studies, we suggest that movement on the western part of the Altyn Tagh Fault was probably initiated during the Oligocene (>30 Ma) and that fault propagation to its eastern tip occurred during the middle-late Miocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSAES..65...79R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSAES..65...79R"><span>Deformation within the Pisco <span class="hlt">Basin</span> <span class="hlt">sedimentary</span> record (southern Peru): Stratabound orthogonal vein sets and their impact on fault development</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rustichelli, Andrea; Di Celma, Claudio; Tondi, Emanuele; Bianucci, Giovanni</p> <p>2016-01-01</p> <p>This outcrop-based study reports diffuse joints and veins, normal to strike-slip fault zones and minor folds that developed, from Miocene to Quaternary, within the clastic to siliceous <span class="hlt">sedimentary</span> record of the forearc Pisco <span class="hlt">Basin</span> of southern Peru. Patterns, orientations, dimensional parameters and other outcrop-scale characteristics of the various deformation features are illustrated and their genetic mechanisms and timing of development are inferred. These new structural data and interpretations allow a better constraint of the structural style and evolution of the Pisco <span class="hlt">Basin</span>, and can represent useful guidelines for characterizing the outcrop-scale deformation affecting similar forearc <span class="hlt">basins</span> along the Peruvian coast. Major results of this study are that the development of the documented deformation features, their patterns, dimensional parameters and kinematics seem influenced by local perturbations of the paleostress field by mechanic processes partly independent of plate tectonics forces. These processes include strain localization on both pre-existing and progressively forming new structural discontinuities, and cyclic switches of the horizontal, principal stress axes σ2 and σ3. In particular, we discuss how different normal fault patterns, from sub-parallel to multidirectional/polygonal, could form in a same deformation phase in response of the local σ2/σ3 magnitude ratio, as an evolution of stratabound, mutually orthogonal vein sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/675978','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/675978"><span>Petroleum resource potential of <span class="hlt">sedimentary</span> <span class="hlt">basins</span> on the Pacific Margin of Canada. Open File Number 3629</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hannigan, P.K.</p> <p>1998-11-01</p> <p>The objective of this report is to provide an overview of the petroleum geology of Canada`s west coast <span class="hlt">basins</span> and to present quantitative estimates of the oil and gas resources contained in those <span class="hlt">basins</span>. Based on geographic and tectonic considerations, the <span class="hlt">basins</span> and sub-<span class="hlt">basins</span> were grouped into three general assessment regions: Queen Charlotte, Georgia, and Tofino. The oil and gas potential is calculated using a subjective assessment technique termed conceptual play analysis, which assumes that the individual sizes of pools in a properly defined play form a natural geological population and that the distribution of pool sizes within that population is log-normal. The pool size distribution is then combined with an additional distribution describing the number of prospects and the marginal probabilities of risk factors to calculate an estimate of both play potential and individual undiscovered pool sizes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10128315','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10128315"><span>[Mechano-chemical self-organization and nonlinear dynamics in <span class="hlt">sedimentary</span> <span class="hlt">basins</span>]. Technical progress report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1993-03-01</p> <p>The central theme of this project is that the reaction, transport and mechanical (RTM) processes affect each other so strongly that <span class="hlt">basin</span> diagenesis takes on a qualitatively different behavior than what would be predicted by the analysis of the individual processes separately. In Figs. 1 and 2 we see schematic <span class="hlt">basin</span> cross-sections that emphasize a few of the diagenetic phenomena arising from the strong coupling of RTM processes. <span class="hlt">Basin</span> diagenesis allows for a great richness of phenomena (Fig. 1) including the genesis of a (formation localized) basal seal, dynamic transbasinal top seal, fault related side seals, episodic fluid release and smaller scale compartmentation within and adjacent to the <span class="hlt">basin</span>-scale overpressured compartment and also (Fig. 2) fingered reaction fronts and upwardly migrating petroleum and auto-localized petroleum (through petroleum-induced porosity preservation). The phenomena of Figs. 1 and 2 arise through feedback loops in the RTM process network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7018941','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7018941"><span>[Mechano-chemical self-organization and nonlinear dynamics in <span class="hlt">sedimentary</span> <span class="hlt">basins</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1993-01-01</p> <p>The central theme of this project is that the reaction, transport and mechanical (RTM) processes affect each other so strongly that <span class="hlt">basin</span> diagenesis takes on a qualitatively different behavior than what would be predicted by the analysis of the individual processes separately. In Figs. 1 and 2 we see schematic <span class="hlt">basin</span> cross-sections that emphasize a few of the diagenetic phenomena arising from the strong coupling of RTM processes. <span class="hlt">Basin</span> diagenesis allows for a great richness of phenomena (Fig. 1) including the genesis of a (formation localized) basal seal, dynamic transbasinal top seal, fault related side seals, episodic fluid release and smaller scale compartmentation within and adjacent to the <span class="hlt">basin</span>-scale overpressured compartment and also (Fig. 2) fingered reaction fronts and upwardly migrating petroleum and auto-localized petroleum (through petroleum-induced porosity preservation). The phenomena of Figs. 1 and 2 arise through feedback loops in the RTM process network.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70034748','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70034748"><span><span class="hlt">Sedimentary</span> <span class="hlt">basin</span> effects in Seattle, Washington: Ground-motion observations and 3D simulations</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Frankel, Arthur; Stephenson, William; Carver, David</p> <p>2009-01-01</p> <p>Seismograms of local earthquakes recorded in Seattle exhibit surface waves in the Seattle <span class="hlt">basin</span> and <span class="hlt">basin</span>-edge focusing of S waves. Spectral ratios of Swaves and later arrivals at 1 Hz for stiff-soil sites in the Seattle <span class="hlt">basin</span> show a dependence on the direction to the earthquake, with earthquakes to the south and southwest producing higher average amplification. Earthquakes to the southwest typically produce larger <span class="hlt">basin</span> surface waves relative to S waves than earthquakes to the north and northwest, probably because of the velocity contrast across the Seattle fault along the southern margin of the Seattle <span class="hlt">basin</span>. S to P conversions are observed for some events and are likely converted at the bottom of the Seattle <span class="hlt">basin</span>. We model five earthquakes, including the M 6.8 Nisqually earthquake, using 3D finite-difference simulations accurate up to 1 Hz. The simulations reproduce the observed dependence of amplification on the direction to the earthquake. The simulations generally match the timing and character of <span class="hlt">basin</span> surface waves observed for many events. The 3D simulation for the Nisqually earth-quake produces focusing of S waves along the southern margin of the Seattle <span class="hlt">basin</span> near the area in west Seattle that experienced increased chimney damage from the earthquake, similar to the results of the higher-frequency 2D simulation reported by Stephenson et al. (2006). Waveforms from the 3D simulations show reasonable agreement with the data at low frequencies (0.2-0.4 Hz) for the Nisqually earthquake and an M 4.8 deep earthquake west of Seattle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.5967P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.5967P"><span>Geodynamical and Geochemical Features of Oil Generation in <span class="hlt">Sedimentary</span> <span class="hlt">Basin</span> of Volga-Ural Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Plotnikova, I.</p> <p>2009-04-01</p> <p>Oil and gas prospects of Paleozoic <span class="hlt">sedimentary</span> rocks of Volga-Ural Anticline (VUA) various researchers evaluate in different ways. More than 150 oil fields in Paleozoic formations were discovered in the eastern half of Republic of Tatarstan of the East European Platform. There were not found any significant fields in the western areas of investigation region. According to many investigators, the western part of the Tatarstan has unfavourable geological structure from oil and gas potential view. Solution of problem concerning revealing HC source for the fields of Volga-Ural oil and gas province certainly would alow to discuss about further prospects of this territory. Data available evidence that during Paleozoic time, an area of the present-day South-Tatarian Arch (STA) and North-Tatarian Arch was a passive continental margin along which a sediments rocks up to 2 km thick was accumulated. Generation potential of organic matter containing in increased concentrations in domanikoid deposits was obtained. It has been discovered that the cumulative production in some oil areas of the Romashkino oil field substantially exceeds formerly proven, recoverable, reserves. Moreover, the volume of oil produced has already significantly exceeded the amount of oil that the Domanik strata could have generated as supposed source rocks of the South Tatarstan arch and the adjacent areas. Cumulative oil production in Tatarstan has already reached 3.0B tons, thus substantially exceeding 709M tons, calculated geochemically on the basis of the Paleozoic source rock potentials of all <span class="hlt">sedimentary</span> strata. This discrepancy obviously shows the impossibility for the commercial amounts of hydrocarbons of being generated from the available material of the <span class="hlt">sedimentary</span> cover. Some experts explain this phenomenon by the errors made in the reserve estimates. But another consider this as the inflow or replenishment by the hydrocarbon flow from the crystalline basement along the faults. Who is right</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4230H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4230H"><span>Tectono-<span class="hlt">sedimentary</span> evolution of the Neuquén <span class="hlt">basin</span> (Argentina) between 39°S and 41°S during the Neogene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huyghe, D.; Bonnel, C.; Nivière, B.; Messager, G.; Dhont, D.; Fasentieux, B.; Hervouët, Y.; Xavier, J.-P.</p> <p>2012-04-01</p> <p><span class="hlt">Sedimentary</span> rocks deposited in foreland <span class="hlt">basins</span> are of primary interest, because they record the interactions between the growth of the orogenic wedge, the isostatic readjustment of the lithosphere, the variations of base-level and earth surface process. The Neuquén <span class="hlt">basin</span> (32°S - 41°S) is a triangular shape foreland <span class="hlt">basin</span> located on the eastern flank of the Andes. Its filling began during the late Triassic, first as back arc <span class="hlt">basin</span> context and as compressive foreland <span class="hlt">basin</span> since the upper Cretaceous. The structural inheritance is thus important and old basement structures, like the Huincul Ridge, generate significant variations of both deformation and shortening. Its Mesozoic history is well constrained due to its hydrocarbon potential. In comparison, its Cenozoic history remains poorly documented. The modern configuration of this <span class="hlt">basin</span> results from several successive compressive tectonic phases. The last one is dated from the Miocene (Quechua phase) and has conditioned the segmentation of the foreland <span class="hlt">basin</span> in several intra-mountainous sub-<span class="hlt">basins</span>, whose <span class="hlt">sedimentary</span> filling could reach several hundred meters. In this work, we document the relative chronology of the geological events and the <span class="hlt">sedimentary</span> processes that have governed the Cenozoic history of the southern part of the Neuquen <span class="hlt">basin</span>, to discriminate the relative rules of climatic and structural controlling factors on the evolution of the depocentres. Several NNW-SSE oriented intra-mountainous <span class="hlt">basins</span> exist in this part of the Andes (Collon Cura <span class="hlt">basin</span> and Catan Lil <span class="hlt">basin</span>). On the contrary the associated foreland <span class="hlt">basin</span> (Picun Leufu <span class="hlt">basin</span>) is relatively underformed and is bounded to the North by the Huincul ridge and the North Patagonian massif to the South. Fifteen <span class="hlt">sedimentary</span> sections have been studied along the Rio Limay River in the southern border of the <span class="hlt">basin</span>, from the range to the external part of the foreland. The sedimentation is discontinuous in time and important retrogradations of the depocentres</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUSMMA11A..03N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUSMMA11A..03N"><span>Finite element modeling of hydrothermal fluid flow in Peace River Arch of Western Canada <span class="hlt">Sedimentary</span> <span class="hlt">Basin</span>: implications for dolomitization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niu, Y.; Yang, J.</p> <p>2009-05-01</p> <p>A finite element computer modeling approach, integrated with existing geological, geochemical and geophysical data, was used to address the diagenetic process of dolomitization in Western Canada <span class="hlt">Sedimentary</span> <span class="hlt">Basin</span> (WCSB). A 2-D conceptualized model was developed to simulate hydrothermal flow in particular for the packland play type dolomitization in Peace River Arch of WCSB. Our numerical results indicate that faults serve as important pathways for the ascending hydrothermal fluids driven by buoyancy force due to temporal and spatial changes in temperature. Both steady state and transient computations were conducted to reveal suitable hydraulic conditions under which the modeled temperature within the aquifer system is consistent with observed values in the targeted study area. A series of numerical case studies were carried out to investigate key factors controlling hydrothermal fluid flow, including fault penetration depth, width and permeability, and its connectivity with the host rock units.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJEaS.tmp..107H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJEaS.tmp..107H"><span>Porous media of the Red River Formation, Williston <span class="hlt">Basin</span>, North Dakota: a possible <span class="hlt">Sedimentary</span> Enhanced Geothermal System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hartig, Caitlin M.</p> <p>2016-09-01</p> <p>Fracture-stimulated enhanced geothermal systems (EGS) can be developed in both crystalline rocks and <span class="hlt">sedimentary</span> <span class="hlt">basins</span>. The Red River Formation (Ordovician) is a viable site for development of a <span class="hlt">sedimentary</span> EGS (SEGS) because the formation temperatures exceed 140 °C and the permeability is 0.1-38 mD; fracture stimulation can be utilized to improve permeability. The spatial variations of the properties of the Red River Formation were analyzed across the study area in order to understand the distribution of subsurface formation temperatures. Maps of the properties of the Red River Formation-including depth to the top of the formation, depth to the bottom of the formation, porosity, geothermal gradient, heat flow, and temperature-were produced by the Kriging interpolation method in ArcGIS. In the future, these results may be utilized to create a reservoir simulation model of an SEGS in the Red River Formation; the purpose of this model would be to ascertain the thermal response of the reservoir to fracture stimulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.5078T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.5078T"><span>Rock Magnetic and Grain Size Variation Along A 50m Cretaceous <span class="hlt">Sedimentary</span> Section of The Marilia Formation (bauru <span class="hlt">Basin</span>), Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamrat, E.; Ernesto, M.; Watanabe, J.; Saad, A. R.; Fulfaro, V. J.</p> <p></p> <p>We present a detailed rock magnetic investigation of a <span class="hlt">sedimentary</span> section from the Marilia Formation of the Bauru <span class="hlt">Basin</span> (22.22S, 49.96W), Brasil. Sampling was con- ducted over 0.5m interval of a 50m Late Cretaceous <span class="hlt">sedimentary</span> deposit. The deposits are consists of coarse to conglomeratic sandstones with abundant calciferous cement and nodules. A total of 81 samples from 67 sites have carried out using hysteresis loop and thermomagnetic curves in order to identify the magnetic mineral and distribution of their grain-size. Trends in rock magnetic parameters with remanent saturation be- low 300mT and moderate coercivity of remanence are consistent with a contribution of Pseudo-single domain to small Multi-domain magnetite. High temperature exper- iments of the magnetic susceptibility up to 700C indicate abundant magnetite with minor contribution of titanomaghemite. Changes in hysteresis parameters are consis- tent with changes in the relative amounts of the different magnetite size fractions. On the basis of rock magnetic investigation, a sample of the Marilia Formation appears to be a reliable recorder of the geomagnetic field during sediment deposition. Their straightforward mineralogy and minimal changes in magnetic concentration consti- tute an opportunity to examine not only rock magnetic and grain size variation, but directional changes and magnetostratigraphy data as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC53C1222B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC53C1222B"><span>The Efficacy and Potential of Renewable Energy from Carbon Dioxide that is Sequestered in <span class="hlt">Sedimentary</span> <span class="hlt">Basin</span> Geothermal Resources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bielicki, J. M.; Adams, B. M.; Choi, H.; Saar, M. O.; Taff, S. J.; Jamiyansuren, B.; Buscheck, T. A.; Ogland-Hand, J.</p> <p>2015-12-01</p> <p>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 <span class="hlt">sedimentary</span> <span class="hlt">basins</span>. 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 <span class="hlt">sedimentary</span> <span class="hlt">basins</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009917','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009917"><span>Distribution, Statistics, and Resurfacing of <span class="hlt">Large</span> Impact <span class="hlt">Basins</span> on Mercury</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fassett, Caleb I.; Head, James W.; Baker, David M. H.; Chapman, Clark R.; Murchie, Scott L.; Neumann, Gregory A.; Oberst, Juergen; Prockter, Louise M.; Smith, David E.; Solomon, Sean C.; Strom, Robert G.; Xiao, Zhiyong; Zuber, Maria T.</p> <p>2012-01-01</p> <p>The distribution and geological history of <span class="hlt">large</span> impact <span class="hlt">basins</span> (diameter D greater than or equal to 300 km) on Mercury is important to understanding the planet's stratigraphy and surface evolution. It is also informative to compare the density of impact <span class="hlt">basins</span> on Mercury with that of the Moon to understand similarities and differences in their impact crater and <span class="hlt">basin</span> populations [1, 2]. A variety of impact <span class="hlt">basins</span> were proposed on the basis of geological mapping with Mariner 10 data [e.g. 3]. This <span class="hlt">basin</span> population can now be re-assessed and extended to the full planet, using data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. Note that small-to- medium-sized peak-ring <span class="hlt">basins</span> on Mercury are being examined separately [4, 5]; only the three largest peak-ring <span class="hlt">basins</span> on Mercury overlap with the size range we consider here. In this study, we (1) re-examine the <span class="hlt">large</span> <span class="hlt">basins</span> suggested on the basis of Mariner 10 data, (2) suggest additional <span class="hlt">basins</span> from MESSENGER's global coverage of Mercury, (3) assess the size-frequency distribution of mercurian <span class="hlt">basins</span> on the basis of these global observations and compare it to the Moon, and (4) analyze the implications of these observations for the modification history of <span class="hlt">basins</span> on Mercury.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAESc.114..611L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAESc.114..611L"><span>Late Jurassic to Early Cretaceous <span class="hlt">sedimentary</span>-tectonic development in the Chengde <span class="hlt">Basin</span>, Yanshan fold-thrust belt, North China Craton</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Jian; Zhao, Yue; Liu, Ankun; Ye, Hao</p> <p>2015-12-01</p> <p>The Chengde <span class="hlt">Basin</span> is located in the central part of the Yanshan fold-thrust belt in the northern North China Craton. The sediments in the Upper Jurassic to Lower Cretaceous Tuchengzi Formation in the Chengde <span class="hlt">Basin</span> provide a detrital record of <span class="hlt">basin</span> dynamics and uplift of the <span class="hlt">basin</span> margins during that time. We analyzed the <span class="hlt">sedimentary</span> facies, paleocurrents, and provenance of the Tuchengzi Formation in the Chengde <span class="hlt">Basin</span> for the period of the Late Jurassic and Early Cretaceous shortening in the Yanshan fold-thrust belt. Four <span class="hlt">sedimentary</span> facies associations have been identified in the Tuchengzi Formation, corresponding to proximal fan, mid-fan, distal alluvial fan, and fluvial facies. The transport and distribution of the Upper Jurassic to Lower Cretaceous sediments in the Chengde <span class="hlt">Basin</span> was controlled by the faults bounding the <span class="hlt">basin</span>. Paleocurrent indicators and provenance data of conglomerate clasts reveal that the sediments of the Tuchengzi Formation in the northern part of the Chengde <span class="hlt">Basin</span> were delivered from source regions to the north of the <span class="hlt">basin</span>. The early sediments of the Tuchengzi Formation in the southern part of the <span class="hlt">basin</span> comprise a suite of fluvial deposits, similar to the fluvial sediments in the northern part of the <span class="hlt">basin</span>, and their paleocurrent data and the compositions of conglomerate clasts also suggest a northern source. However, the subsequent sedimentation in the Tuchengzi Formation in the southern part of the <span class="hlt">basin</span> changed markedly to proximal fan facies, with sediments being derived from the south of the <span class="hlt">basin</span>, according to the paleocurrent data and conglomerate clast lithology. The Sandaohe sheet, which is located in the southeast limb of the Chengde syncline, is not a klippe formed as a result of long-distance northward thrusting, but an autochthonous pop-up tectonic wedge generated by N-S shortening during the Early Cretaceous sedimentation of the Tuchengzi Formation. The sedimentation ended before the onset of the Early Cretaceous volcanic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.2066R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.2066R"><span>Synthesis of Late Cretaceous-Quaternary tectonic, <span class="hlt">sedimentary</span> and magmatic processes and <span class="hlt">basin</span> formation related to episodic subduction-collision in the easternmost Mediterranean region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robertson, Alastair; Kinnaird, Timothy; McCay, Gillian; Palamakumbura, Romesh; Taslı, Kemal</p> <p>2015-04-01</p> <p>Mesozoic oceanic crust of the easternmost Mediterranean has experienced northwards subduction during Late Cretaceous-Cenozoic, either continuously or discontinuously based on kinematic evidence. Much of the existing information on sedimentation within the easternmost Mediterranean oceanic <span class="hlt">basin</span> comes from the non-emplaced continental margins of the Levant and North Africa. In addition, <span class="hlt">sedimentary</span> <span class="hlt">basins</span> related to plate convergence are recorded along the northern margin of the Southern Neotethyan ocean, mainly in the Kyrenia Range of northern Cyprus and its extension into the Misis Mountains of southern Turkey, coupled with the adjacent submerged areas. In a setting of only incipient continental collision such as the easternmost Mediterranean the <span class="hlt">sedimentary</span> <span class="hlt">basins</span> would be expected to remain entirely submarine. In contrast, the Kyrenia Range has been strongly uplifted and subaerially exposed during Late Pliocene-Quaternary time. This allows the recognition of a number of discrete phases of <span class="hlt">sedimentary</span> <span class="hlt">basin</span> formation: 1. Late Cretaceous (Campanian-Maastrichtian): silicic volcanism to create a subaqueous volcaniclastic apron; 2. Maastrichtian-Paleocene: pelagic carbonate deposition interspersed with proximal gravity flows and within-plate type alkaline volcanics; 3. Early Eocene: <span class="hlt">large</span>-scale <span class="hlt">sedimentary</span> melange (olistostrome) emplacement; 4. Late Eocene-Late Miocene: terrigenous gravity-flow deposition in a deep-water fault dissected 'fore arc' setting. Initial, Late Eocene non-marine coarse clastic alluvial fan deposition was succeeded by Oligocene-Miocene deep-marine siliciclastic gravity flow deposits, fining and shallowing upwards during the Late Miocene; 5. Messinian: localised precipitation of evaporites in small fault-controlled <span class="hlt">basins</span>; 6. Pliocene: shallow-marine siliciclastic-carbonate deposition in a shelf-depth, overall regressive setting; 7. Latest Pliocene to mid-Pleistocene: gravitational accumulation of coarse talus along a strongly uplifting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EP%26S...69..108A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EP%26S...69..108A"><span>Surface wave group velocity in the Osaka <span class="hlt">sedimentary</span> <span class="hlt">basin</span>, Japan, estimated using ambient noise cross-correlation functions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asano, Kimiyuki; Iwata, Tomotaka; Sekiguchi, Haruko; Somei, Kazuhiro; Miyakoshi, Ken; Aoi, Shin; Kunugi, Takashi</p> <p>2017-08-01</p> <p>Inter-station cross-correlation functions estimated using continuous ambient noise or microtremor records were used to extract the seismic wave propagation characteristics of the Osaka <span class="hlt">sedimentary</span> <span class="hlt">basin</span>, Japan. Temporary continuous observations were conducted at 15 sites in the Osaka <span class="hlt">basin</span> between 2011 and 2013. The data were analyzed using seismic interferometry. The target period range was 2-8 s. Cross-correlations between all of the possible station pairs were calculated and stacked to produce a year-long data set, and Rayleigh wave signals in the vertical and radial components and Love wave signals in the transverse component were identified from the results. Simulation of inter-station Green's functions using the finite difference method was conducted to check the performance of the current three-dimensional velocity structure model. The measured time lag between the observed and theoretical Green's functions was less than 2 s for most station pairs, which is less than the wave period of interest in the target frequency range. Group velocity tomography was applied to group delay times estimated by means of multiple filter analysis. The estimated group velocities for longer periods of 5-8 s exhibited spatial variation within the <span class="hlt">basin</span>, which is consistent with the bedrock depth distribution; however, the group velocities for shorter periods of 2-3 s were almost constant over the studied area. The waveform and group velocity information obtained by seismic interferometry analysis can be useful for future reconstruction of a three-dimensional velocity structure model in the Osaka <span class="hlt">basin</span>.[Figure not available: see fulltext.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611152P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611152P"><span>Geological and geochemical characteristics of <span class="hlt">sedimentary</span> rocks in Kremna, <span class="hlt">basin</span> (Serbia)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perunović, Tamara; Jovančićević, Branimir; Brčeski, Ilija; Šajnović, Aleksandra; Stojanović, Ksenija; Simić, Vlada; Kašanin-Grubin, Milica</p> <p>2014-05-01</p> <p>Studying lacustrine sediments is important because of their potential economic value since they often bear coal, oil shales and non-metallic mineral raw materials. Besides this, lacustrine sediments offer valuable information on the climate conditions which existed during the sedimentation. In Serbia there are 14 lacustrine <span class="hlt">basins</span> spanning in age from Oligocene to Lower Pliocene. The aim of this study was to examine Lower Miocene Kremna <span class="hlt">basin</span>, located in southwest Serbia. Kremna <span class="hlt">basin</span> is a small <span class="hlt">basin</span>, covering 15km2, but sedimentologically very interesting. For the purpose of this study, 43 sediment samples were taken from a borehole at different depths, from surface to 343 m depth of the <span class="hlt">basin</span>. The borehole ended in weathered serpentinite. Mineralogical composition of sediments was determined using thin-sections and X-ray diffraction analysis, contents of macro-and microelements and rare-earth elements were determined by ICP-ES and ICP-MS techniques. Also, elemental analysis was applied to determine the contents of carbon, sulphur and nitrogen and n-alkanes, isoprenoide aliphatic alkanes and bitumen were also determined using GC-MS technique. Mineralogical analyses proved presents of several lithological types in Kremna <span class="hlt">basin</span>: clastic sediments, tuffs, tuffaceous sediments, marlstones, dolomites, magnezites, and coal of non-economic value. Occurrence of sirlezite and sepiolite was also determined. Furthermore, according to all obtained results two faciae were determined: alluvial-marginal lacustrine and intrabasinal. Alluvial-marginal facies originated from predominantly ultramafic rocks which underlie the <span class="hlt">basin</span>. Magnezites and Mg-marls and Mg-dolomites are dominant sediments in this facies. These sediments formed under arid, slightly saline conditions. Intrabasinal facies is represented mostly with marls, Mg-marls and dolomitic limestones. These sediments were deposited under a more humid climate with increase in paleoproductivity. The uppermost sediments of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6998353','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6998353"><span>The application of fossil resin biomarkers to oil-source correlation in some Australian <span class="hlt">sedimentary</span> <span class="hlt">basins</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Alexander, R.; Larcher, A.V.; Kagi, R.I. ); Price, P.L. )</p> <p>1989-03-01</p> <p>Suites of aromatic and saturated compounds which are indicative of plant resins from Araucariaceae have been identified in widely distributed sediments of Jurassic age from the Eromanga <span class="hlt">Basin</span>. Similar biomarker assemblages have been shown not to be present in sediments of Permian age from the Cooper <span class="hlt">Basin</span>. Some crude oils contained in reservoirs of Jurassic to Cretaceous age have been shown to contain the biomarker assemblage characteristic of the sediments of Jurassic age and, therefore, appear to have been derived from sediments within the Eromanga <span class="hlt">Basin</span>. Other crude oils in reservoirs of this age, together with all crude oils from reservoirs of Permian age do not contain the biomarker signature of the sediments of Jurassic age, and are therefore presumed to have been derived from the Permian sediments within the Eromanga <span class="hlt">Basin</span>. Other crude oils in reservoirs of this age, together with all crude oils from reservoirs of Permian age do not contain the biomarker signature of the sediments of Jurassic age, and are therefore presumed to have been derived from the Permian sediments of the Cooper <span class="hlt">Basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914205D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914205D"><span>Pervasive faulting revealed by acoustic blanking: a potential explanation for <span class="hlt">large</span> thermal anomalies in the Anglo-Paris <span class="hlt">Basin</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dentzer, Jacques; Bruel, Dominique; Delescluse, Matthias; Chamot-Rooke, Nicolas; Beccaletto, Laurent; Lopez, Simon; Courrioux, Gabriel; Violette, Sophie</p> <p>2017-04-01</p> <p>Based on new seismic interpretations, this work explores different scenarios to explain major temperature variations in the Anglo-Paris <span class="hlt">Basin</span>. The work considers both the horizontal and vertical dimensions of these thermal heterogeneities by coupling measurements from geothermal wells with temperature profiles. In addition to detailed geological structures (anticline and faults), reprocessing and interpretation of seismic data have revealed the presence of vertically extending zones with characteristic low-energy seismic facies affecting a <span class="hlt">large</span> part of the <span class="hlt">sedimentary</span> pile. Such observations are known in other <span class="hlt">sedimentary</span> contexts and are interpreted as fractured lithology. We consider their potential role regarding fluid flows in continental domain geothermal modelling for an intracratonic <span class="hlt">sedimentary</span> <span class="hlt">basin</span>. Different fault and fracture scenarios clearly show their contribution to the heterogeneity observed in the <span class="hlt">basin</span>'s temperature field, which cannot be explained either by conductive phenomena with heterogeneous radiogenic production nor by flows without vertical leakage via the faults or fractured zones affecting the <span class="hlt">sedimentary</span> pile. An important consequence of this work would then be to research these zones to localize them systematically and understand their origin, and to then confirm their hydrodynamic properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JVGR..308..158K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JVGR..308..158K"><span>Volcano-<span class="hlt">sedimentary</span> characteristics in the Abu Treifiya <span class="hlt">Basin</span>, Cairo-Suez District, Egypt: Example of dynamics and fluidization over <span class="hlt">sedimentary</span> and volcaniclastic beds by emplacement of syn-volcanic basaltic rocks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khalaf, E. A.; Abdel Motelib, A.; Hammed, M. S.; El Manawi, A. H.</p> <p>2015-12-01</p> <p>This paper describes the Neogene lava-sediment mingling from the Abu Treifiya <span class="hlt">Basin</span>, Cairo-Suez district, Egypt. The lava-sediment interactions as peperites have been identified for the first time at the study area and can be used as paleoenvironmental indicators. The identification of peperite reflects contemporaneous time relationship between volcanism and sedimentation and this finding is of primary importance to address the evolutional reconstruction of the Abu Treifiya <span class="hlt">Basin</span>. Characterization of the facies architecture and textural framework of peperites was carried out through detailed description and interpretation of their outcrops. The peperites and <span class="hlt">sedimentary</span> rocks are up to 350 m thick and form a distinct stratigraphic framework of diverse lithology that is widespread over several kilometers at the study area. Lateral and vertical facies of the peperites vary from sediment intercalated with the extrusive/intrusive basaltic rocks forming peperitic breccias to lava-sediment contacts at a <span class="hlt">large</span> to small scales, respectively. Peperites encompass five main facies types ascribed to: (i) carbonate sediments-hosted fluidal and blocky peperites, (ii) lava flow-hosted blocky peperites, (iii) volcaniclastics-hosted fluidal and blocky peperites, (iv) sandstone/siltstone rocks-hosted blocky peperites, and (iv) debris-flows-hosted blocky peperites. Soft sediment deformation structures, vesiculated sediments, sediments filled-vesicles, and fractures in lava flows indicate that lava flows mingled with unconsolidated wet sediments. All the peperites in this study could be described as blocky or fluidal, but mixtures of different clast shapes occur regardless of the host sediment. The presence of fluidal and blocky juvenile clasts elucidates different eruptive styles, reflecting a ductile and brittle fragmentation. The gradual variation from fluidal to blocky peperite texture, producing the vertical grading is affected by influencing factors, e.g., the viscosity, magma</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUSM.U24A..01G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUSM.U24A..01G"><span>The Role of Groundwater Flow and Faulting on Hydrothermal Ore Formation in <span class="hlt">Sedimentary</span> <span class="hlt">Basins</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garven, G.</p> <p>2006-05-01</p> <p>Sediment-hosted ore formation is thought to occur as a normal outcome of <span class="hlt">basin</span> evolution, due to deep groundwater flow, heat transport, and reactive mass transport ---all of which are intimately coupled. This paper reviews recent attempts to understand the hydrologic and geochemical processes forming some of the world's largest sediment-hosted ores. Several questions still dominate the literature (driving forces for flows, source and controls on metal acquisition, concentrations of ore-forming components, timing and duration, role of faults, effects of transient flows). This paper touches upon all of these questions. Coupled reactive transport models have been applied for understanding the genesis of sandstone-hosted uranium ores of North America and Australia, red-bed copper ores of North America and northern Europe, carbonate-hosted MVT lead-zinc ores of the U.S. Midcontinent and northwestern Canada, and the carbonate- hosted lead-zinc ores of Ireland and southeast France. Good progress has been made in using these computational methods for comparing and contrasting both carbonate hosted (MVT and Irish types) and shale- hosted (SEDEX type) Pb-Zn deposits. The former are mostly associated with undeformed carbonate platforms associated with distal orogenic belts and the later are mostly associated with extensional <span class="hlt">basins</span> and failed rifts that are heavily faulted. Two giant ore provinces in extensional <span class="hlt">basins</span> provide good examples of structural control on reactive mass transport: shale-hosted Pb-Zn ores of the Proterozoic McArthur <span class="hlt">basin</span>, Australia, and shale-hosted Pb-Zn-Ba ores of the Paleozoic Kuna <span class="hlt">basin</span>, Alaska. For the McArthur <span class="hlt">basin</span>, hydrogeologic simulations of thermally-driven free convection suggest a strong structural control on fluid flow created by the north-trending fault systems that dominate this Proterozoic extensional <span class="hlt">basin</span>. Brines appear to have descended to depths of a few kilometers along the western side of the <span class="hlt">basin</span>, migrated laterally to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940030921','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940030921"><span>Effects due to overlapping <span class="hlt">large</span> impact <span class="hlt">basins</span> on Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frey, Herbert; Reidy, Anne Marie; Roark, James H.; Stockman, Stephanie</p> <p>1994-01-01</p> <p>Many ancient, highly degraded <span class="hlt">large</span> impact <span class="hlt">basins</span> exist on Mars. In many cases these <span class="hlt">basins</span> overlap or are overlapped by more easily observed, presumably younger, impact <span class="hlt">basins</span>. While impact <span class="hlt">basin</span> overlap is becoming more recognized, the effects of such overlap have only occassionally been described. Such effects will depend on a variety of factors including the absolute and relative size of the <span class="hlt">basins</span>, the degree of overlap, the state of the lithosphere and its thermal gradient at the time of impact, and the time between impacts. There now exists enough evidence for overlapping <span class="hlt">basins</span> of different sizes that some of these can be discussed. This paper highlights some examples of the obvious effects of <span class="hlt">basin</span> overlap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Tectp.635....6B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Tectp.635....6B"><span>Late Cretaceous to Late Eocene Hekimhan <span class="hlt">Basin</span> (Central Eastern Turkey) as a supra-ophiolite <span class="hlt">sedimentary</span>/magmatic <span class="hlt">basin</span> related to the later stages of closure of Neotethys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Booth, Matthew G.; Robertson, Alastair H. F.; Tasli, Kemal; İnan, Nurdan</p> <p>2014-11-01</p> <p>The Hekimhan <span class="hlt">Basin</span> is here put forward as a type example of a globally important class of <span class="hlt">basin</span>, known as a supra-ophiolite <span class="hlt">basin</span>. Such <span class="hlt">basins</span> form after the emplacement of ophiolitic (i.e. oceanic) rocks onto a passive continental margin, but long prior to continental collision. The Hekimhan <span class="hlt">Basin</span> developed as part of the northern margin of the Tauride microcontinent during the collision and suturing of two Neotethyan oceans to the north, namely the Inner Tauride Ocean and the İzmir-Ankara-Erzincan ocean. The <span class="hlt">basin</span> records two main stages of tectonic development, during latest Cretaceous to Late Eocene time. The first phase of <span class="hlt">basin</span> development during the Late Cretaceous (Maastrichtian) began with the erosion of emplaced ophiolitic rocks, resulting in non-marine clastic sedimentation. Subsequently, the <span class="hlt">basin</span> rapidly subsided, in response to inferred regional crustal extension, resulting in the deposition of hemipelagic marls and local sapropelic mudstones. The axial parts of the <span class="hlt">basin</span> experienced alkaline, within-plate-type, basaltic volcanism. The Late Maastrichtian culminated in deposition of shallow-marine carbonates. Overlying Paleocene sediments are restricted to thin, localised, marine evaporates, associated with a low-angle unconformity. The second stage of <span class="hlt">basin</span> development began during the Early Eocene with deposition of shallow-marine carbonates, coupled with localised basaltic volcanism, again of extensional type. The <span class="hlt">basin</span> emerged during the Mid-Late Eocene in a late-stage collisional to post-collisional setting. Compressional deformation <span class="hlt">largely</span> reflects post-suture tightening. A short-lived marine transgression occurred during the Mid-Miocene. The <span class="hlt">basin</span> was later deformed by both left-lateral and right-lateral strike-slip. Several different tectonic models are considered, notably extension related to the northward pull of a still-subducting oceanic slab, and back-arc extension related to northward subduction of Neotethys (to the south). The first</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11179715','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11179715"><span>Permian, Jurassic and Early Cretaceous palynofloral assemblages from subsurface <span class="hlt">sedimentary</span> rocks in Chuperbhita Coalfield, Rajmahal <span class="hlt">Basin</span>, India.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tripathi, A</p> <p>2001-04-01</p> <p>The results of a palynological analysis of the <span class="hlt">sedimentary</span> sequence of Borehole RCH-151, Chuperbhita Coalfield, Rajmahal <span class="hlt">Basin</span>, Bihar are presented here. The borehole penetrated the Rajmahal Formation (comprising two traps sandwiching an intertrappean bed), the thinly represented Dubrajpur Formation and in its lower part, the Coal Measures. The coal-bearing interval is associated with Scheuringipollenites barakarensis, Faunipollenites varius, Densipollenites indicus, Gondisporites raniganjensis and Densipollenites magnicorpus Assemblage Zones. The presence of these biostratigraphic units indicates correlation with the Barakar Formation (Early Permian) and the Barren Measures and Raniganj Formations (both Late Permian). This is the first record, in the Chuperbhita Coalfield, of Late Permian strata, which appear to represent a condensed sequence. Prior to the present study, the Permian succession was thought to have been associated entirely with the Barakar Formation. The overlying Dubrajpur Formation yielded a distinct spore-pollen assemblage (in association with the first report of dinoflagellate, Phallocysta), which is assigned to the newly identified Callialasporites turbatus palynozone of latest Early to early Middle Jurassic age. The diverse spore-pollen flora of the intertrappean bed (Rajmahal Formation) incorporates several age marker taxa, viz. Undulatisporites, Leptolepidites, Klukisporites, Ruffordiaspora, and Coptospora. The assemblages from intertrappean beds are correlated with the Ruffordiaspora australiensis palynozone of Australia. Thus the palynodating indicates Permian, latest Early to early Mid-Jurassic and Early Cretaceous age for the strata studied. This is the first record of definite Jurassic microfossils from the non-marine sequence of Rajmahal <span class="hlt">Basin</span>, India.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JHyd..519.3541X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JHyd..519.3541X"><span>Impact of <span class="hlt">sedimentary</span> provenance and weathering on arsenic distribution in aquifers of the Datong <span class="hlt">basin</span>, China: Constraints from elemental geochemistry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Xianjun; Wang, Yanxin; Ellis, Andre; Liu, Chongxuan; Duan, Mengyu; Li, Junxia</p> <p>2014-11-01</p> <p>Arsenic (As)-contaminated aquifer sediments from Datong <span class="hlt">basin</span>, China have been analyzed to infer the provenance and depositional environment related to As distribution in the aquifer sediments. The As content in the sediments ranged from 2.45 to 27.38 mg/kg with an average value of 9.54 mg/kg, which is comparable to the average value in modern unconsolidated sediments. However, minor variation in As concentration with depth has been observed in the core. There was a significant correlation between Fe, and Al and As, which was attributed to the adsorption or co-precipitation of As onto/with Fe oxides/hydroxides and/or Fe-coated clay minerals. Post-Archean Australian Shale (PAAS)-normalized REEs patterns of sediment samples along the borehole were constant, and the sediments had a notably restricted range of LaN/YbN ratios from 0.7 to 1.0. These results suggested that the provenance of the Datong <span class="hlt">basin</span> remained similar throughout the whole depositional period. The analysis of major geochemical compositions confirmed that all core sediments were from the same <span class="hlt">sedimentary</span> source and experienced significant <span class="hlt">sedimentary</span> recycling. The co-variation of As, V/Al, Ni/Al and chemical index of alteration (CIA) values in the sediments along the borehole suggested that As distribution in the sediments was primarily controlled by weathering processes. The calculated CIA values of the sediments along the borehole indicate that a relative strong chemical weathering occurred during the deposition of sediments at depths of ∼35 to 88 m, which was corresponding to the depth at which high As groundwater was observed at the site. Strong chemical weathering favored the deposition of Fe-bearing minerals including poorly crystalline and crystalline Fe oxide mineral phases and concomitant co-precipitation of As with these minerals in the sediments. Subsequent reductive dissolution of As-bearing poorly crystalline and crystalline Fe oxides would result in the enrichment of As in groundwater</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1188944','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1188944"><span>Impact of <span class="hlt">sedimentary</span> provenance and weathering on arsenic distribution in aquifers of the Datong <span class="hlt">basin</span>, China: Constraints from elemental geochemistry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xie, Xianjun; Wang, Yanxin; Ellis, Andre; Liu, Chongxuan; Duan, Mengyu; Li, Junxia</p> <p>2014-11-01</p> <p>Arsenic (As)-contaminated aquifer sediments from Datong <span class="hlt">basin</span>, China have been analyzed to infer the provenance and depositional environment related to As distribution in the aquifer sediments. The As content in the sediments ranged from 2.45 to 27.38 mg/kg with an average value of 9.54 mg/kg, which is comparable to the average value in modern unconsolidated sediments. However, minor variation in As concentration with depth has been observed in the core. There was a significant correlation between Fe, and Al and As, which was attributed to the adsorption or co-precipitation of As onto/with Fe oxides/hydroxides and/or Fe-coated clay minerals. Post-Archean Australian Shale (PAAS)-normalized REEs patterns of sediment samples along the borehole were constant, and the sediments had a notably restricted range of La-N/Yb-N ratios from 0.7 to 1.0. These results suggested that the provenance of the Datong <span class="hlt">basin</span> remained similar throughout the whole depositional period. The analysis of major geochemical compositions confirmed that all core sediments were from the same <span class="hlt">sedimentary</span> source and experienced significant <span class="hlt">sedimentary</span> recycling. The co-variation of As, V/Al, Ni/Al and chemical index of alteration (CIA) values in the sediments along the borehole suggested that As distribution in the sediments was primarily controlled by weathering processes. The calculated CIA values of the sediments along the borehole indicate that a relative strong chemical weathering occurred during the deposition of sediments at depths of similar to 35 to 88 m, which was corresponding to the depth at which high As groundwater was observed at the site. Strong chemical weathering favored the deposition of Fe-bearing minerals including poorly crystalline and crystalline Fe oxide mineral phases and concomitant co-precipitation of As with these minerals in the sediments. Subsequent reductive dissolution of As-bearing poorly crystalline and crystalline Fe oxides would result in the enrichment of As in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612665F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612665F"><span>Geothermal potential of Caledonian granites underlying Upper Palaeozoic <span class="hlt">sedimentary</span> <span class="hlt">basins</span> astride the Iapetus Suture Zone in Ireland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fritschle, Tobias; Daly, J. Stephen; Whitehouse, Martin J.; McConnell, Brian; Buhre, Stephan</p> <p>2014-05-01</p> <p>Upper Palaeozoic <span class="hlt">sedimentary</span> <span class="hlt">basins</span> in Ireland overlie crystalline rocks within the Caledonian Iapetus Suture Zone. Beneath these <span class="hlt">basins</span>, Lower Palaeozoic rocks, formed and deformed during the Caledonian orogenic cycle, were intruded by c. 420-390 Ma late-tectonic granites at various tectonic levels. These include the subsurface Kentstown and Glenamaddy granites discovered by mineral exploration drilling. While these granites comprise actual targets for Enhanced Geothermal System (EGS) exploration, several others likely exist based on geophysical considerations. In order to test the regional geothermal potential, the buried granites as well as analogue exposed rocks are being investigated geochemically. The geothermal potential of the intrusives depends on their heat production rate (HPR), which is calculated using rock density and concentrations of the heat producing elements (HPE) uranium, thorium and potassium. In spite of their close spacing and similar ages, the whole-rock geochemistry of the granites varies significantly, but with no obvious geographical control (Fritschle et al., 2013; 2014). The granite HPR values range from 1.4 μW/m3 for the Dhoon Granite (Isle of Man) to 4.9 μW/m3 for the Drogheda Granite (Ireland). This compares with the average HPR for a 'typical' granite of 2.7 μW/m3 (Goldstein et al., 2009). It is demonstrated that an elevated HPR of a granite can be related to enrichment in one of the HPE alone (e.g., uranium-enrichment in the Foxdale Granite (Isle of Man), or thorium-enrichment in the Drogheda Granite). Enrichment in HPE in a granite may occur due to different reasons including hydrothermal (re-) distribution of uranium, or the assimilation of thorium-rich wall-rocks. Hence, the distribution of the HPE in particular minerals, veins and source lithologies, along with the petrophysical characteristics of the <span class="hlt">sedimentary</span> <span class="hlt">basins</span> and the granites' petrogenesis, are currently being investigated as possible mechanisms controlling their</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/769000','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/769000"><span>Canyon drainage induced mixing over a <span class="hlt">large</span> <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stalker, J.</p> <p>2000-05-01</p> <p>Complex terrain surrounding urbanized <span class="hlt">basins</span> around the world has long been recognized to strongly affect the characteristics of vertical transport and mixing of pollutants. The Department of Energy's Vertical Transport and Mixing (VTMX) program will investigate mixing processes within night-time boundary layers over <span class="hlt">large</span> urban <span class="hlt">basins</span>. The program will launch several field experiments within the Salt Lake City <span class="hlt">basin</span> in the coming years. This modeling study, like many other studies being undertaken by the participants of the VTMX programs, is intended to complement the proposed field experiments by numerically examining some of the flow interactions known to occur in <span class="hlt">large</span> <span class="hlt">basins</span>. Using idealized simulations, we particularly investigate drainage flows from deep canyons similar to those along the Wasatch Front into the Salt Lake City <span class="hlt">basin</span>. Literature shows that under favorable conditions, drainage flows can generate bore waves that may propagate ahead of the density current (e.g., Simpson 1969; Simpson 1982; Crook and Miller 1985). Existence and frequency of such bore waves can profoundly influence the spatial and temporal variability of vertical transport and mixing within <span class="hlt">large</span> <span class="hlt">basins</span>. If bore waves do occur on a regular basis within the Salt Lake City <span class="hlt">basin</span> (a task for the upcoming experiments to determine), then understanding the <span class="hlt">basin</span>-scale conditions under which these waves are produced and how they may propagate and interact with the city's buildings will be of great importance in characterizing transport and mixing processes within the <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5289981','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5289981"><span>[sup 40]Ar/[sup 39]Ar ages of Challis volcanic rocks and the initiation of Tertiary <span class="hlt">sedimentary</span> <span class="hlt">basins</span> in southwestern Montana</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>M'Gonigle, J.W. ); Dalrymple, G.B. )</p> <p>1993-10-01</p> <p>[sup 40]Ar/[sup 39]Ar ages on single sanidine crystals from rhyolitic tuffs and ash flow tuffs within the uppermost and lowermost parts of the volcanic sequence of the Horse Prairie and Medicine Lodge topographic <span class="hlt">basins</span>, southwestern Montana, show that these volcanic rocks were emplaced between about 48.8[+-]0.2 Ma and 45.9[+-]0.2 Ma, and are correlative with the Eocene Challis Volcanic Group of central Idaho. Sanidine ages on tuffs at the base of the Tertiary lacustrine, paludal, and fluvial <span class="hlt">sedimentary</span> sequence, which unconformably overlies the volcanic sequence, suggest that sedimentation within an ancestral <span class="hlt">sedimentary</span> <span class="hlt">basin</span> that predated the development of the modern Horse Prairie and Medicine Lodge <span class="hlt">basins</span> began in the middle Eocene. 22 refs., 3 figs., 2 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP51D3556B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP51D3556B"><span>Andean <span class="hlt">Basins</span> Morphometry: Assesing South American <span class="hlt">Large</span> Rivers' Source Areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bean, R. A.; Latrubesse, E. M.</p> <p>2014-12-01</p> <p>Presently there are no regional-scale morphometric analyses of Andean fluvial <span class="hlt">basins</span>. Therefore, we created a continental-scale database of these <span class="hlt">basins</span>. Our data covers over an area 1,000,000 km2 of the Andes, from Venezuela to Argentina. These <span class="hlt">basins</span> are the source of some of the largest rivers in the world including the Amazon, Orinoco, Parana, and Magdalena. Morphometric parameters including shape factor, relief ratio, longitudinal profiles and different indices of <span class="hlt">basin</span> elevation were calculated based on the CGIAR SRTM 4.1 DEM (~90 m resolution). FAO Hydrosheds were used to segment the DEM by major catchment and then manually cut at the Andean zone. In the North and Central Andes, this produced over 500,000 subcatchments, which we reduced to 619 by setting minimum catchment area to 100 km2. We then integrate lithologic data from DNPM geologic data. Our results indicate that <span class="hlt">sedimentary</span> lithologies dominate Central Andean catchments (n=268,k=4), which cover an area 767,00 km2, while the Northern Andean catchments (covering 350,000 km2) are more varied, dominated by volcanics in the Pacific (n=78), a <span class="hlt">sedimentary</span> (48%) dominant mix in the Caribbean (n=138) and 60% <span class="hlt">sedimentary</span> in the Amazon-Orinoco subregion catchments (n=138). Elevation averages are smallest in the north Andes and average maximum elevations (6,026 m) in the Argentinian catchments (n=65) of the Central Andes are the highest. Shape factors range from 0.49 to 0.58 in the North and 0.52 to 0.58 in the Central Andes. There are clear differences in all categories between region and subregion, but that difference does not hinge on a single morphometric or geologic parameter. Morphometric parameters at a watershed scale (listed in Table) are analyzed and hydrologic data from gauging stations throughout the Andes (n=100) are used to compare morphometric parameters with lithology and characteristics from the <span class="hlt">basin</span> hydrograph (peak discharge timing, minimum and maximum discharge, and runoff).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992SedG...78..155D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992SedG...78..155D"><span>Oxygen-isotope evidence for upward, cross-formational porewater flow in a <span class="hlt">sedimentary</span> <span class="hlt">basin</span> near maximum burial</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Caritat, Patrice; Baker, Julian C.</p> <p>1992-07-01</p> <p>Authigenic ankerite in the gas-bearing mid-Permian Aldebaran Sandstone (Denison Trough, Queensland, Australia) has an anomalously light oxygen-isotopic composition ( δ 18O SMOW range: +7.6 to +14.4‰ ) and exhibits a trend of 18O-enrichment from the base to the top of the unit. Textural relationships, together with burial and thermal modelling, indicate that this carbonate precipitated at temperatures of about 100 to 140°C, when the sequence approached maximum burial during the Late Triassic. This implies that ankerite precipitated from porewater very depleted in 18O with respect to marine water ( δ 18O SMOW = -9 to -5‰ ). The formation of this deep, relatively high-temperature ankerite is difficult to reconcile with downward percolation of meteoric water at that time since the <span class="hlt">basin</span> was then undergoing its first burial/compactional cycle. We interpret the ankerite to have precipitated from porewater expelled upward from the earliest Permian Reids Dome beds. This thick unit, consisting mainly of high-latitude continental sandstones, mudrocks and coals, was initially saturated with very 18O-depleted meteoric water ( δ 18O SMOW ≈ -17‰ ) partly derived from melted snow and ice, and is likely to have undergone overpressuring during rapid burial (at rates up to 1 km/Ma). Tectonically induced expulsion of "connate meteoric" porewater out of the Reids Dome beds took place as the sequence approached maximum burial prior to Late Triassic <span class="hlt">basin</span> uplift. This water was flushed upward through the overlying units, retaining a (modified) meteoric isotopic signature, which was recorded by the precipitating ankerite. Computer modelling of heat transport, isotopic mass balance and water mixing quantitatively shows that this interpretation is viable, lending support to the suggested mechanism of upward, cross-formational porewater flow deep in a <span class="hlt">sedimentary</span> <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSM.T43B..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSM.T43B..08S"><span>Processes in Environmental Depositional Systems and Deformation in <span class="hlt">Sedimentary</span> <span class="hlt">Basins</span>: Goals for Exoloration in Mexico</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandoval-Ochoa, J.</p> <p>2005-05-01</p> <p>Among the recent needs to establish new goals in the mexican energy industry to increase the petroleum reserves, has been necessary to recapitulate on some academic an operative concepts and definitions applied to the Petroliferous <span class="hlt">Basins</span> Exploration; first of all, in order to understand the Petroleum System in given tectonophysical framework. The tectonophysical environment experienced by the petroliferous <span class="hlt">basin</span> in the southwestern Gulf of Mexico, merely in the Campeche Sound and adjacent terrestrial regions (Figure 1); has been the result of interaction among the tectonic plates, the Coco's Plate with impingement and subduction beneath the Northamerican Plate and the Yucatán Microplate and even in very deep connection with the oceanic crust of southwesternmost portion of the Gulf of Mexico and the one of the Caribbean sea beneath the gulf of Belize-Honduras. The tectonosedimentary effects in the Campeche Bay starting with the skeleton formed for the Cenozoic Era, kept simultaneous conditions in depositions and deformations because of strain, stress and collapse fields, acted through this Era up to the present day, as observed in the surface Aguayo et al, 1999 and Sandoval, 2000. The involved portions of the crust and its boundaries have also been performing the relative sinking of the mere southwestern centre of the Gulf of Mexico, and the rising of the southeastern lands of Mexico. In the middle contiguity are found the productive Tertiary <span class="hlt">basins</span> of: Comalcalco, Macuspana, Salina del Itsmo, Campeche-Champoton and other in deep waters; all of them, in an arrangement of <span class="hlt">basins</span> among distensive faulted blocks in echelon, falling down to the deep centre of the Gulf Sandoval, op cit. With this scenario and that ones of other <span class="hlt">basins</span>, a recapitulation on concepts and definitions, has been made on the regional natural processes of the environmental depositional systems and on the <span class="hlt">basins</span> analysis in the tectonophysical framework, in order to reflect on the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860021656','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860021656"><span>Potassium metasomatism of volcanic and <span class="hlt">sedimentary</span> rocks in rift <span class="hlt">basins</span>, calderas and detachment terranes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chapin, C. E.; drographic basins.</p> <p>1985-01-01</p> <p>The chemical, mineralogical, and oxygen-isotopic changes accompanying K-metasomatism are described. The similarities with diagenetic reactions in both deep marine and alkaline, saline-lake environments are noted. The common occurrence of K-metasomatism in upper-plate rocks of detachment terranes indicates that the early stage of severe regional extension causes crustal downwarping and, in arid to semi-arid regions, development of closed hydrographic <span class="hlt">basins</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......148C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......148C"><span>Evaluating <span class="hlt">sedimentary</span> <span class="hlt">basins</span> for geothermal power production potential and bottom-hole temperature corrections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crowell, Anna M.</p> <p></p> <p>At present, the risks and costs associated with geothermal energy wildcat exploration are prohibitive. With improved technology, the future may be brighter, and a play fairway analysis, for geothermal exploration can guide development. Comparing geophysical data with geothermal gradient allows identification of potentially economic areas of interest. The play fairway analysis is a common tool used by the petroleum industry to identify areas for potential exploration. The analysis identifies areas in the Denver, Illinois, Michigan, and Williston <span class="hlt">Basins</span> with the highest development potential. A great deal of data have potential for a play fairway analysis, but data quality is problematic due to systematic errors in bottom-hole temperatures (BHTs). Corrections to bottom-hole temperatures are necessary due to the perturbation of temperature caused by the drilling mud, and can range from 5 to 30 °C. Correction schemes for bottom-hole temperatures can be applied to both the energy-in-place estimates and play fairway analyses. The Harrison equation is the most accurate for <span class="hlt">basins</span> less than 4.5 km deep. The Kehle correction is the most accurate for <span class="hlt">basins</span> deeper than 4.5 km. Chapter II explains why BHTs grouped by depth are more statistically robust than those grouped by geochronological unit. Chapter III demonstrates why the Harrison Equation is the best correction method to use for BHTs. Chapters IV and V give the volumetric energy-in-place for the Denver, Illinois, and Michigan <span class="hlt">Basins</span> for discrete temperature ranges, and Chapter 6 provides the final Play Fairway Favorability maps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T11B2063T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T11B2063T"><span>Hidden Rift Structure Beneath a Thick <span class="hlt">Sedimentary</span> <span class="hlt">Basin</span> in the Niigata Region, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takeda, T.; Enescu, B.; Asano, Y.; Obara, K.; Sekiguchi, S.</p> <p>2010-12-01</p> <p>Niigata region is located in a high-strain-rate zone, along the easternmost margin of the back-arc <span class="hlt">basin</span> of the Sea of Japan (Sagiya et al., 2000, Okamura et al., 1995). In this region, two M6.8 inland earthquakes with reverse fault type focal mechanism, having NW-SE compression, occurred in 2004 and 2007. The reverse fault system may indicate present reactivation of the rift structure formed as a result of normal faulting when the Sea of Japan opened in the Miocene (Sato, 1994). Therefore, imaging the spatial extent of the rift structure is important to reveal the seismotectonics and occurrence mechanism of inland earthquakes. To resolve the fine structure beneath the Niigata region, we have installed a dense temporary network of 300 seismic stations and performed a regional tomography analysis. The temporary seismic network was designed with a multi-scale station spacing of 3 to 5 km in and around the aftershock areas of the two <span class="hlt">large</span> earthquakes, and of ~10 km for the surrounding region. The 3D velocity tomography analysis and relocation of earthquakes were performed using the tomoDD software (Zhang and Thurber, 2003). We used 777 events that occurred after the installation of the temporary network and 703 events that were recorded only by the permanent seismic network (Hi-net) before the temporary network deployment. The initial 3D velocity model was constructed by using the 3D shallow velocity structure provided by the “Japan Seismic Hazard Information Station” (J-SHIS; Fujiwara et al., 2009) of NIED. The horizontal and vertical grid spacing were of 5 ~ 10 km and 2 ~ 4 km, respectively. The tomography analysis enabled us to delineate the fine subsurface structure. The high and low velocity pattern corresponds well to the Bouguer gravity anomalies mapped in the region. The velocity model shows a wide and relatively low velocity (< 5 km/sec for the P-wave velocity) band extending in a NE-SW direction. The band widens and narrows along its extent. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRE..121.2239S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRE..121.2239S"><span>A <span class="hlt">sedimentary</span> origin for intercrater plains north of the Hellas <span class="hlt">basin</span>: Implications for climate conditions and erosion rates on early Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salese, Francesco; Ansan, Veronique; Mangold, Nicolas; Carter, John; Ody, Anouck; Poulet, Francois; Ori, Gian Gabriele</p> <p>2016-11-01</p> <p>Understanding the origin (volcanic or <span class="hlt">sedimentary</span>) and timing of intercrater plains is crucial for deciphering the geological evolution of Mars. We have produced a detailed geological map of the intercrater plains north of the Hellas <span class="hlt">basin</span>, based on images from the Mars Express High-Resolution Stereo Camera, the Mars Reconnaissance High-Resolution Imaging Science Experiment, and Context. Erosional windows and fresh impact craters provide a way of studying the lithology of intercrater plain units. They are composed predominantly of light-toned <span class="hlt">sedimentary</span> rocks with subhorizontal bedding over a broad extent (greater than tens of kilometers), showing cross-bedding stratifications locally. The broad extent, geometry, and flat topography of these sediments favor a formation by aqueous processes (alluvial and lacustrine) rather than airfall (eolian and volcaniclastic). The Late Noachian ( 3.7 Ga) <span class="hlt">sedimentary</span> plains are locally covered by dark-toned, rough-textured lava flows of Late Hesperian age ( 3.3 Ga). Fe/Mg phyllosilicates were detected within <span class="hlt">sedimentary</span> rocks, whereas volcanic rocks contain pyroxene and lack signatures of alteration, in agreement with interpretations made from texture and morphology. In erosional windows, the superimposition of <span class="hlt">sedimentary</span> rocks by younger volcanic flows enables the estimation of an erosion rate of 1000 nm yr-1 during the Hesperian period (3.3-3.7 Ga). Thus, our study shows that an intense <span class="hlt">sedimentary</span> cycle occurred on the northern rim of the Hellas <span class="hlt">basin</span> before and during the Late Noachian, leading to the formation of widespread <span class="hlt">sedimentary</span> plains, which were then eroded, in agreement with a gradual change in the climatic conditions in this period, and later covered by volcanic flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1917782G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917782G"><span>Analyses on Origin of positive gravity anomalies of <span class="hlt">sedimentary</span> <span class="hlt">basins</span> of the Ross Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Jinyao; Yang, Chunguo; Ji, Fei; Wang, Wei; Shen, Zhongyan</p> <p>2017-04-01</p> <p>We have adopted gridded products describing surface elevation, ice-thickness and the sea floor and subglacial bed elevation south of 60◦ S from Bedmap2 and north of 60◦ S from JGP95E to calculate Bouguer and isostatic gravity anomaly of the Ross Sea region based on the DTU10 free-air gravity anomaly.Taking a view of the free-air, Bouguer and isostatic gravity anomalies, it is unusual that high values overlay the Victoria Land <span class="hlt">Basin</span>, Central Trough, Northern <span class="hlt">Basin</span> and Northern Central Trough while basement highs are associated with low value. A number of studies have attributed the high gravity anomalies across the depocenters to high-density volcanics deep within the <span class="hlt">basins</span> or magmatic intrusions within the region of the thinned crust or upper mantle (e. g., Edwards et al., 1987). According to the conclusion from Karner et al. (2005), the anticorrelation of gravity anomalies with sediment basement can be reproduced if the flexural strength of the lithosphere during the late Cretaceous rifting is significantly lower than the flexural strength of the lithosphere at the Oligocene and Neogene time of sedimentation. We note that the isostatic gravity anomalies are higher than the free-air gravity anomalies adjacent to the Transantarctic Mountains, and vice versa away from the Transantarctic Mountains. We may ignore the constraints offered by the tranditional isostasy in the local gravity studies of the Ross Sea <span class="hlt">basins</span>, especially advancing the concept of high density material in the lower crust or upper mantle. In particular, the modeled gravity does not laterally integrate to zero, due to the existence of unbalanced forces induced by mantle. Along the outer shelf uplift zone surrouding Antarctica, the positive gravity belt has higher values in free-air gravity anomalies than those in isostatic gravity anomalies. Meanwhile, the positive gravity belt of isostatic gravity anomalies almost disappears in the background anomalies of 20 mGal to 10 mGal facing the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950024444','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950024444"><span>Laboratory simulated hydrothermal alteration of <span class="hlt">sedimentary</span> organic matter from Guaymas <span class="hlt">Basin</span>, Gulf of California. Ph.D. Thesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Leif, Roald N.</p> <p>1993-01-01</p> <p>High temperature alteration of <span class="hlt">sedimentary</span> organic matter associated with marine hydrothermal systems involves complex physical and chemical processes that are not easily measured in most natural systems. Many of these processes can be evaluated indirectly by examining the geochemistry of the hydrothermal system in the laboratory. In this investigation, an experimental organic geochemical approach to studying pyrolysis of <span class="hlt">sedimentary</span> organic matter is applied to the hydrothermal system in the Guaymas <span class="hlt">Basin</span>, Gulf of California. A general survey of hydrothermal oils and extractable organic matter (bitumen) in hydrothermally altered sediments identified several homologous series of alkanones associated with a high temperature hydrothermal origin. The alkanones range in carbon number from C11 to C30 with no carbon number preference. Alkan-2-ones are in highest concentrations, with lower amounts of 3-, 4-, 5- (and higher) homologs. The alkanones appear to be pyrolysis products synthesized under extreme hydrothermal conditions. Hydrous pyrolysis and confinement pyrolysis experiments were performed to simulate thermally enhanced diagenetic and catagenetic changes in the immature <span class="hlt">sedimentary</span> organic matter. The extent of alteration was measured by monitoring the n-alkanes, acyclic isoprenoids, steroid and triterpenoid biomarkers, polycyclic aromatic hydrocarbons and alkanones. The results were compared to bitumen extracts from sediments which have been naturally altered by a sill intrusion and accompanied hydrothermal fluid flow. These pyrolysis experiments duplicated many of the organic matter transformations observed in the natural system. Full hopane and sterane maturation occurred after 48 hr in experiments at 330 deg C with low water/rock mass ratios (0.29). A variety of radical and ionic reactions are responsible for the organic compound conversions which occur under extreme hydrothermal conditions. Short duration pyrolysis experiments revealed that a portion of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.H14A..01K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.H14A..01K"><span>Potential Environmental Impacts of CO2 Storage in <span class="hlt">Sedimentary</span> <span class="hlt">Basins</span>: Results From the Frio Brine Test, Texas, USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kharaka, Y. K.; Cole, D. R.; Hovorka, S. D.; Phelps, T. J.; Nance, S.</p> <p>2006-12-01</p> <p>Deep saline aquifers in <span class="hlt">sedimentary</span> <span class="hlt">basins</span>, including depleted petroleum reservoirs, provide advantageous locations close to major anthropogenic sources of CO2 and potential capacity for the storage of huge volumes of this greenhouse gas. To investigate the potential for the long-term storage of CO2 in such aquifers, 1600 t of CO2 were injected at 1500 m depth into a 24-m-thick "C" sandstone section of the Frio Formation, a regional saline aquifer in the U.S. Gulf Coast. Fluid samples obtained before CO2 injection from the injection well and an observation well 30 m updip showed a Na-Ca-Cl type brine with 93,000 mg/L TDS at near saturation with CH4 at reservoir conditions; gas analyses show CH4 comprised ~95% of dissolved gas, but CO2 was low at 0.3%. Following CO2 breakthrough, 51 h after injection, samples showed sharp drops in pH (6.5 to 5.7), pronounced increases in alkalinity (100 to 3000 mg/L as HCO3) and in Fe (30 to 1100 mg/L), and significant shifts in the isotopic compositions of H2O, Sr, DIC, and CH4. These data coupled with geochemical modeling indicate rapid dissolution of minerals, especially calcite and iron oxyhydroxides caused by lowered pH (~3.0 initially) of the brine in contact with the injected supercritical CO2. These geochemical parameters, together with perfluorocarbon tracer gases (PFTs) proved effective in mapping the distribution and interactions of the injected CO2 in the Frio "C". They are being used to track the migration of the injected CO2 into the local shallow groundwater and into the overlying Frio "B", comprised of a 4-m-thick sandstone bed and separated from the "C" by ~15 m of shale, muddy sandstone and siltstone beds. Results obtained to date from the four monitoring groundwater wells perforated (26-29 m) in the Beaumont aquifer show some temporal chemical changes. These changes, however, are tentatively attributed to natural variations and recharge events caused by the construction of a mud pit at the site, and not to leakage</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H51C1482T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H51C1482T"><span>Parametric Analysis of the feasibility of low-temperature geothermal heat recovery in <span class="hlt">sedimentary</span> <span class="hlt">basins</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tomac, I.; Caulk, R.</p> <p>2016-12-01</p> <p>The current study explored the feasibility of heat recovery through the installation of heat exchangers in abandoned oil and gas wells. Finite Element Methods (FEM) were employed to determine the effects of various site specific parameters on production fluid temperature. Specifically, the study parameterized depth of well, subsurface temperature gradient, <span class="hlt">sedimentary</span> rock conductivity, and flow rate. Results show that greater well depth is associated with greater heat flow, with the greatest returns occurring between depths of 1.5 km and 7 km. Beyond 7 km, the rate of return decreases due to a non-linear increase of heat flow combined with a continued linear increase of pumping cost. One cause for the drop of heat flow was the loss of heat as the fluid travels from depth to the surface. Further analyses demonstrated the benefit of an alternative heat exchanger configuration characterized by thermally insulated sections of the upward heat exchanger. These simulations predict production fluid temperature gains between 5 - 10 oC, which may be suitable for geothermal heat pump applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4255P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4255P"><span>Modal analysis of 2-D <span class="hlt">sedimentary</span> <span class="hlt">basin</span> from frequency domain decomposition of ambient vibration array recordings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poggi, Valerio; Ermert, Laura; Michel, Clotaire; Fäh, Donat</p> <p>2014-05-01</p> <p>The frequency domain decomposition is a well-established spectral technique used in civil engineering to analyze and monitor the modal response of buildings and structures. The method is based on singular value decomposition of the cross-power spectral density matrix from simultaneous array recordings of ambient vibration. This method is advantageous to retrieve not only the resonance frequencies of the investigated structure, but also the corresponding modal shapes without using an absolute reference. This is an important piece of information, which can be used to identify areas of minimum and maximum ground motion on the structure. We apply this approach to evaluate the SH and P-SV resonance characteristics of 2D Alpine <span class="hlt">sedimentary</span> valleys through decomposition of ambient vibration recordings from linear seismic arrays deployed perpendicularly to the valley axis. Results are presented for a set of synthetic models, initially used to validate the method, and for a real acquisition survey performed in the Rhone valley (Switzerland). For the real case, up to six separate resonant frequencies, together with their corresponding modal shapes, were retrieved for the SH case using the frequency domain decomposition method. We then compare these mode shapes with results from classical site-to-reference spectral ratios and solutions from analytical and numerical modal analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoJI.200..615P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoJI.200..615P"><span>Modal analysis of 2-D <span class="hlt">sedimentary</span> <span class="hlt">basin</span> from frequency domain decomposition of ambient vibration array recordings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poggi, Valerio; Ermert, Laura; Burjanek, Jan; Michel, Clotaire; Fäh, Donat</p> <p>2015-01-01</p> <p>Frequency domain decomposition (FDD) is a well-established spectral technique used in civil engineering to analyse and monitor the modal response of buildings and structures. The method is based on singular value decomposition of the cross-power spectral density matrix from simultaneous array recordings of ambient vibrations. This method is advantageous to retrieve not only the resonance frequencies of the investigated structure, but also the corresponding modal shapes without the need for an absolute reference. This is an important piece of information, which can be used to validate the consistency of numerical models and analytical solutions. We apply this approach using advanced signal processing to evaluate the resonance characteristics of 2-D Alpine <span class="hlt">sedimentary</span> valleys. In this study, we present the results obtained at Martigny, in the Rhône valley (Switzerland). For the analysis, we use 2 hr of ambient vibration recordings from a linear seismic array deployed perpendicularly to the valley axis. Only the horizontal-axial direction (SH) of the ground motion is considered. Using the FDD method, six separate resonant frequencies are retrieved together with their corresponding modal shapes. We compare the mode shapes with results from classical standard spectral ratios and numerical simulations of ambient vibration recordings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.3600M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.3600M"><span>About the Relation Between Geodynamics of the <span class="hlt">Sedimentary</span> <span class="hlt">Basin</span> and the Properties of Crude Oil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Muslimov, R.; Plotnikova, I.</p> <p>2012-04-01</p> <p>Earlier, we wrote and reported about the modern geodynamic activity of the territory of South-Tatar arch, where the Romashkino oil field. We identified a periodic change in flow rates of oil and oil density at Romashkino and other oil fields of the South Tatar arch. Now we have studied the composition of oils and bitumoids from uneven (in terms of age) deposites of the <span class="hlt">sedimentary</span> cover and basement rocks in the zones of possible hydrocarbon seepage in the central squares of Romashkinskoye field. The results of the comparative studies allowed us to come to the conclusion that the formation of oil-bearing deposits of Romashkinskoye field owes to the income and mixing of hydrocarbons (HC) fluids from different sources. The analysis of geological and production data (GPD) that was held during the many years of exploitation of the development wells of Romashkinskoye field by TatNIPIneft under the direction of I.F. Glumov suggests contemporary inflow of hydrocarbons in the industrial oil reservoir of the Pashi horizon of Romashkinskoye field and the existence of localized areas of inflow of new portions of HC. A number of criteria was worked out in the analysis of the GPD; that allowed us to identify among the total number of wells those, in which the process of hydrocarbon seepage was recorded with the greatest probability. Such wells were called anomalous. One of the directions of this research was to study the geochemical characteristics of oil from anomalous wells and to determine the degree of similarity and difference between this oil and the oil from both normal wells (in which the signs of deep seepage is not recorded), and bituminoid from the crystalline basement and <span class="hlt">sedimentary</span> cover. If the hypothesis of a recurrent (also in modern times) influx of deep hydrocarbon is correct, then the oil from the anomalous wells should have specific features in comparison with the wells located outside the areas of the expected inflow. The results of geochemical studies of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H33C1337N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H33C1337N"><span>Wetland river flow interaction in a <span class="hlt">sedimentary</span> formation of the white Volta <span class="hlt">basin</span>, Ghana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nyarko, B. K.; Diekkruger, B.; Van De Giesen, N.; Barry, B.</p> <p>2011-12-01</p> <p>Groundwater resources in the floodplain wetlands of the White Volta River <span class="hlt">basin</span> of Ghana is a major source of water for irrigation activities of communities living around and baseflow to sustain the flow of the river. Hydrology of the floodplain wetlands in the <span class="hlt">basin</span> are complex, characterized by temporally variable storage volumes with erratic contribution to streamflow. For the continual usage of groundwater resources in the floodplains there is a need to study the form of interaction between the main river and floodplain wetlands. The study, adopted the PM-WIN (MODFLOW) model for simulating the interaction between the wetland and stream. Additionally, the lower boundary discharge output from the HYDRUS-1D model is the estimated recharge. This input quantifies the temporal and spatial variations in sub-surfaces discharges in the floodplain wetland. The simulation of the sub-surface hydraulic head of the wetland indicates a systematic variation relative to the White Volta River response to changes in the rainfall pattern. The interaction conditions vary from season to season with March, April, and May showing the least leakage (estimated values of 0.03mm/day, 0.06mm/day, and 0.15 mm/day, respectively) from the river into the floodplain wetland. Notably, the interaction between the wetland and the river as simulated is bidirectional. With most of the flow coming out from the river into the floodplain wetland, this condition persists in the months of August and September.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012HydJ...20...61O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012HydJ...20...61O"><span>Groundwater recharge to a <span class="hlt">sedimentary</span> aquifer in the topographically closed Uley South <span class="hlt">Basin</span>, South Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ordens, Carlos M.; Werner, Adrian D.; Post, Vincent E. A.; Hutson, John L.; Simmons, Craig T.; Irvine, Benjamin M.</p> <p>2012-02-01</p> <p>The chloride mass balance (CMB) and water-table fluctuation (WTF) analysis methods were used to estimate recharge rates in the Uley South <span class="hlt">Basin</span>, South Australia. Groundwater hydrochemistry and isotope data were used to infer the nature of recharge pathways and evapotranspiration processes. These data indicate that some combination of two plausible processes is occurring: (1) complete evaporation of rainfall occurs, and the precipitated salts are washed down and redissolved when recharge occurs, and (2) transpiration dominates over evaporation. It is surmised that sinkholes predominantly serve to by-pass the shallow soil zone and redistribute infiltration into the deeper unsaturated zone, rather than transferring rainfall directly to the water table. Chlorofluorocarbon measurements were used in approximating recharge origins to account for coastal proximity effects in the CMB method and pumping seasonality was accounted for in the WTF-based recharge estimates. Best estimates of spatially and temporally averaged recharge rates for the <span class="hlt">basin</span> are 52-63 and 47-129 mm/year from the CMB and WTF analyses, respectively. Adaptations of both the CMB and WTF analyses to account for nuances of the system were necessary, demonstrating the need for careful application of these methods.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994GeoRu..83..787G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994GeoRu..83..787G"><span>Mineral deposit formation in Phanerozoic <span class="hlt">sedimentary</span> <span class="hlt">basins</span> of north-east Africa: the contribution of weathering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Germann, Klaus; Schwarz, Torsten; Wipki, Mario</p> <p>1994-12-01</p> <p>The intra- and epicontinental <span class="hlt">basins</span> in north-east Africa (Egypt, Sudan) bear ample evidence of weathering processes repeatedly having contributed to the formation of mineral deposits throughout the Phanerozoic. The relict primary weathering mantle of Pan-African basement rocks consists of kaolinitic saprolite, laterite (in places bauxitic) and iron oxide crust. On the continent, the reaccumulation of eroded weathering-derived clay minerals (mainly kaolinite) occurred predominantly in fluvio-lacustrine environments, and floodplain and coastal plain deposits. Iron oxides, delivered from ferricretes, accumulated as oolitic ironstones in continental and marine sediments. Elements leached from weathering profiles accumulated in continental <span class="hlt">basins</span> forming silcrete and alunite or in the marine environment contributing to the formation of attapulgite/saprolite and phosphorites. The Early Paleozoic Tawiga bauxitic laterite of northern Sudan gives a unique testimony of high latitude lateritic weathering under global greenhouse conditions. It formed in close spatial and temporal vicinity to the Late Ordovician glaciation in north Africa. The record of weathering products is essentially complete for the Late Cretaceous/Early Tertiary. From the continental sources in the south to the marine sinks in the north, an almost complete line of lateritic and laterite-derived deposits of bauxitic kaolin, kaolin, iron oxides and phosphates is well documented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.9513L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.9513L"><span>The tectono-<span class="hlt">sedimentary</span> evolution of North Helvetic Flysch <span class="hlt">basin</span> in Central Alps as revealed by detrital zircon U-Pb age dating and Hf isotope geochemistry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Gang; Winkler, Wilfried; Willett, Sean; Rahn, Meinert</p> <p>2017-04-01</p> <p>Palaeogene syn-tectonic volcanic products sparsely occur in the North Helvetic Flysch, which mainly deposited in the Northern Alpine Foreland <span class="hlt">Basin</span>. However, the volcaniclastic provenance of the North Helvetic Flysch and its counterparts in Central Alps is still a matter of debate. We investigate the Early Oligocene (Rupelian) turibidite deposits to evaluate their temporal and genetic relationship with the hypothetical magmatic provinces and basement. Detrital zircons from several representative localities (Haute-Savoie, Alpe de Taveyannaz, Glarus and Trento area) have been dated by LA-ICP-MS analysis methods. The obtained age patterns are compared with trace element analysis and 176Hf/177Hf isotope of detrital zircons, which indicate the magmatic environment of zircons crystallization. The ages of detrital zircons show two major populations: a <span class="hlt">large</span> dominance (92%) of pre-Alpine zircons (Cadomian, Caledonian, Variscan and post-Variscan, ca. > 252 Ma) as commonly observed in other Alpine Flysch formations, which derive from the basement and <span class="hlt">sedimentary</span> cover of the South Alpine and Austroalpine units. Few Neo-Alpine ones (8%) in the range from Late Eocene to Early Oligocene ( 39.8±0.7-29.7±0.8 Ma) occur, which match the geochronologic data of the Adamello ( 42-33Ma), Biella ( 34-31Ma) and Bergell ( 32-29 Ma) intrusions. With regard to the REE and Hf isotope signatures, it appears that the volcanic fragments were derived from related dykes and surficial extrusions. In addition, the discovery of the minor Neo-Alpine zircons may be due to low zircon production in the volcanic belt along the Palaeo-Insubric line. However, a long distance transport of the syn-<span class="hlt">sedimentary</span> volcanic material and mixing with various Alpine basement and cover sources is also suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V53D3150H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V53D3150H"><span>Investigating Controls on Sedimentation Through Interpretation of the Syntectonic Cretaceous-Paleogene <span class="hlt">Sedimentary</span> Record in the San Juan <span class="hlt">Basin</span> (New Mexico, U.S.A.)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hobbs, K.; Weissmann, G. S.; Fawcett, P. J.</p> <p>2015-12-01</p> <p>The Cretaceous/Paleogene boundary in the southwestern San Juan <span class="hlt">Basin</span> is bracketed by the mudstone-dominated Cretaceous Kirtland Formation, the sandstone-dominated Paleocene Ojo Alamo Sandstone, and the mudstone-dominated Paleocene lower Nacimiento Formation. Geochemical trends of fluvial mudstones from these units indicate changing <span class="hlt">sedimentary</span> source areas through time. While the Kirtland and Nacimiento Formations represent periods of high accommodation within the San Juan <span class="hlt">Basin</span>, the Ojo Alamo Sandstone represents a period of low accommodation and general reworking and transport by southeast-flowing paleorivers. The Kirtland and Nacimiento Formations thin and fine away from their interpreted source area whereas the Ojo Alamo Sandstone thickens and fines away from the source area. Here we investigate the enigmatic <span class="hlt">sedimentary</span> architecture of the Ojo Alamo Sandstone, geochemical evidence for a changing source area through this time period, and the complex relationships between sedimentation, source area, accommodation, and <span class="hlt">basin</span> tectonic evolution. Incorporating new measured sections, petrographic analyses, geochemical trends, and stratigraphic relationships, we propose that the Ojo Alamo Sandstone represents an anomalous short period of low accommodation in the San Juan <span class="hlt">Basin</span> during the early Laramide Orogeny and explore possible intra- and extra-<span class="hlt">basinal</span> tectonic, climatic, and sedimentologic explanations as well as implications for understanding the evolution of the <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916651H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916651H"><span>Grain size indicators of <span class="hlt">sedimentary</span> coupling between hillslopes and channels in a dryland <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hollings, Rory; Michealides, Katerina; Bliss Singer, Michael</p> <p>2017-04-01</p> <p>In dryland landscapes, heterogeneous and short-lived rainstorms generate runoff on slopes and streamflow in channels, which drive sediment movement from hillslope surfaces to channels and the transport of bed material sediment within channels. Long-term topographic evolution of drainage <span class="hlt">basins</span> is partly determined by the relative balance of hillslope sediment supply to channels and the evacuation of channel sediment. However, it is not clear whether supply or evacuation is dominant over longer timescales (>>100 y) within dryland <span class="hlt">basins</span>. One important indicator of local cumulative sediment transport is grain size (GS). On dryland hillslopes, grain size is governed over long timescales by weathering, but on short time scales (events to decades), is controlled by event-driven transport of the debris mantle. In the channel, GS reflects the input of hillslope sediment and the selective transport of particles along the bed. It is currently unknown how these two processes are expressed systematically within GS distributions on slopes and in channels within drylands, but this information could be useful to explain the history of the relative balance between hillslope sediment supply to channels and net sediment transport in the channel. We investigate this problem by combining field measurements of surface sediment grain size distributions in channels and on hillslopes with 1m LiDAR topography, >60 years of rainfall and channel discharge data from the Walnut Gulch Experimental Watershed (WGEW) in Arizona, and simple calculations of grain-sized based local stress distributions for various rainfall and discharge events. Hydrological scenarios of overland flow on hillslopes and channel flow conditions were derived from distributions of historic data at WGEW and were selected to reflect the wide range of storm intensities and durations, and channel discharges. 1) We used three quartiles of the entire distribution of measured discharge values for 80 locations throughout the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6209755','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6209755"><span><span class="hlt">Sedimentary</span> facies, organic facies, and hydrocarbon generation in evaporite sediments of the Mulhouse <span class="hlt">Basin</span>, France</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hofmann, P.M.</p> <p>1992-01-01</p> <p>The sediments of the S unit (lower Oligocene) of the Mulhouse <span class="hlt">Basin</span>, France, display lithofacies characteristic for the deposition in a perennial evaporitic lake that received frequent marine influx. The sediments consist of marls, anhydrites, and halite. The organic content of these sediments stems from algal and most likely bacterial sources. Terrigenous, plant-derived organic matter comprises on average less than 10% of the total organic matter. The mass of the organic matter is concentrated in the marl lithofacies, which display a varve-like lamination. The 2 organic racies correlate with distinct lithofacies. It therefore appears that the deposition of sediments and their organic content was governed by the physical conditions of the lake. The accumulation of organic matter-rich sediments in the S unit of the Mulhouse <span class="hlt">Basin</span> is thought to have been favored by a high paleoproductivity and good to excellent preservation conditions. Low sedimentation rates in conjunction with elevated salinities led to the accumulation of marls rich in organic matter. The kerogens of the S unit can be classified as type II. The organic matter from the sites Amelie II and Berrwiller is immature and corresponds to a maturity level of 0.35 and 0.45% vitrinite reflectance. Petroleum formation resulted in significantly higher amounts of bitumen as expected from shale source rocks of this maturity level. The bitumens are dominated by asphaltenes and NSO-compounds and contain less than 50% hydrocarbons. In the maturity interval from 0.35-0.45% R[sub o], hydrocarbon generation took place in all lithofacies. Hydrocarbons formed via kerogen conversion in the marl-dominated sediments and via asphaltene/NSO-compound conversion in anhydrite-dominated lithofacies. The massive anhydrites of the S unit have already expelled hydrocarbons. The naphthalene patterns of this lithofacies show fractionation effects that resulted from water washing during the phase transition from gypsum to anhydrite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GCarp..67..525S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GCarp..67..525S"><span>Late Miocene <span class="hlt">sedimentary</span> record of the Danube/Kisalföld <span class="hlt">Basin</span>: interregional correlation of depositional systems, stratigraphy and structural evolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sztanó, Orsolya; Kováč, Michal; Magyar, Imre; Šujan, Michal; Fodor, László; Uhrin, András; Rybár, Samuel; Csillag, Gábor; Tőkés, Lilla</p> <p>2016-12-01</p> <p>The Danube / Kisalföld <span class="hlt">Basin</span> is the north-western sub-<span class="hlt">basin</span> of the Pannonian <span class="hlt">Basin</span> System. The lithostratigraphic subdivision of the several-km-thick Upper Miocene to Pliocene <span class="hlt">sedimentary</span> succession related to Lake Pannon has been developed independently in Slovakia and Hungary. A study of the <span class="hlt">sedimentary</span> formations across the entire <span class="hlt">basin</span> led us to claim that these formations are identical or similar between the two <span class="hlt">basin</span> parts to such an extent that their correlation is indeed a matter of nomenclature only. Nemčiňany corresponds to the Kálla Formation, representing locally derived coarse clastics along the <span class="hlt">basin</span> margins (11- 9.5 Ma). The deep lacustrine sediments are collectively designated the Ivanka Formation in Slovakia, while in Hungary they are subdivided into Szák (fine-grained transgressive deposits above basement highs, 10.5 - 8.9 Ma), Endrőd (deep lacustrine marls, 11.6 -10 Ma), Szolnok (turbidites, 10.5 - 9.2 Ma) and Algyő Formations (fine-grained slope deposits, 10 - 9 Ma). The Beladice Formation represents shallow lacustrine deltaic deposits, fully corresponding to Újfalu (10.5 - 8.7 Ma). The overlying fluvial deposits are the Volkovce and Zagyva Formations (10 - 6 Ma). The synoptic description and characterization of these sediments offer a <span class="hlt">basin</span>-wide insight into the development of the <span class="hlt">basin</span> during the Late Miocene. The turbidite systems, the slope, the overlying deltaic and fluvial systems are all genetically related and are coeval at any time slice after the regression of Lake Pannon initiated about 10 Ma ago. All these formations get younger towards the S, SE as the progradation of the shelf-slope went on. The <span class="hlt">basin</span> got filled up to lake level by 8.7 Ma, since then fluvial deposition dominated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008CG.....34..427M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008CG.....34..427M"><span>Two equations of state assembled for basic analysis of multiphase CO 2 flow and in deep <span class="hlt">sedimentary</span> <span class="hlt">basin</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McPherson, Brian J. O. L.; Han, Weon Shik; Cole, Barret S.</p> <p>2008-05-01</p> <p>The purpose of the study presented in this manuscript is to describe and make available two equation-of-state (EOS) algorithms assembled for multiphase flow and transport of carbon dioxide (CO2). The algorithms presented here calculate solubility, compressibility factor, density, viscosity, fugacity, and enthalpy of CO2 in gaseous and supercritical phases, and mixtures or solutions of CO2 in water, as functions of pressure and temperature. Several features distinguish the two algorithms, but the primary distinction concerns treatment of supercritical/gas-phase CO2: one EOS we assembled is based on Redlich and Kwong's original algorithm developed in 1949, and the other is based on an algorithm developed by Span and Wagner in 1996. Both were modified for application to <span class="hlt">sedimentary</span> <span class="hlt">basin</span> studies of multiphase CO2 flow processes, including carbon sequestration applications. We present a brief comparison of these two EOS algorithms. Source codes for both algorithms are provided, including "stand-alone" Matlab © scripts for the interactive calculation of fluid properties at specified P-T conditions and FORTRAN subroutines for inclusion in existing FORTRAN multiphase fluid simulation packages. These routines are intended for fundamental analyses of CO2 sequestration and the like; more advanced studies, such as brine processes and reactive transport, require more advanced EOS algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAESc.147..322W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAESc.147..322W"><span>Palaeogene growth of the northeastern Tibetan Plateau: Detrital fission track and <span class="hlt">sedimentary</span> analysis of the Lanzhou <span class="hlt">basin</span>, NW China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Xiuxi; Deng, Lizheng; Zattin, Massimiliano; Ji, Minxiao; Li, Jijun</p> <p>2017-10-01</p> <p>The Palaeogene evolution of the northeastern Tibetan Plateau remains elusive, because of the paucity of well-dated long-lasting and continuous <span class="hlt">sedimentary</span> records. In this work, we present a detailed detrital apatite fission track thermochronology and stratigraphic study in the Lanzhou <span class="hlt">basin</span>, located on the eastern-most margin of northeastern Tibet, where Eocene to middle Miocene sediments are well preserved. Combining the analysis of sedimentology records and synsedimentary tectonic structures, four regional tectonic phases are deciphered (52-47 Ma, 40-32 Ma, 23-20 Ma and <16 Ma, respectively). These episodes were spaced out by three periods of tectonic stability or quiescence linked to regional relief-reduction. Our apatite fission-track data suggest that far-field stress due to the India-Asia collision had been propagated to this region since early Eocene, and the modern northeastern portion of the Tibetan Plateau has been buildup since then. Thereafter, the growth of the northeastern Tibetan Plateau was dominated by a tectonic activity/inactivity cycle until late Miocene. Thus, the regional growth history appears to have been episodic in nature during the Cenozoic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.205..744E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.205..744E"><span>Measurement of intrinsic and scattering attenuation of shear waves in two <span class="hlt">sedimentary</span> <span class="hlt">basins</span> and comparison to crystalline sites in Germany</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eulenfeld, Tom; Wegler, Ulrich</p> <p>2016-05-01</p> <p>We developed an improved method for the separation of intrinsic and scattering attenuation of seismic shear waves by envelope inversion called Qopen. The method optimizes the fit between Green's functions for the acoustic, isotropic radiative transfer theory and observed energy densities of earthquakes. The inversion allows the determination of scattering and intrinsic attenuation, site corrections and spectral source energies for the investigated frequency bands. Source displacement spectrum and the seismic moment of the analysed events can be estimated from the obtained spectral source energies. We report intrinsic and scattering attenuation coefficients of shear waves near three geothermal reservoirs in Germany for frequencies between 1 and 70 Hz. The geothermal reservoirs are located in Insheim, Landau (both Upper Rhine Graben) and Unterhaching (Molasse <span class="hlt">basin</span>). We compare these three <span class="hlt">sedimentary</span> sites to two sites located in crystalline rock with respect to scattering and intrinsic attenuation. The inverse quality factor for intrinsic attenuation is constant in sediments for frequencies smaller than 10 Hz and decreasing for higher frequencies. For crystalline rock, it is on a lower level and strictly monotonic decreasing with frequency. Intrinsic attenuation dominates scattering except for the Upper Rhine Graben, where scattering is dominant for frequencies below 10 Hz. Observed source displacement spectra show a high-frequency fall-off greater than or equal to 3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70015679','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70015679"><span>Geochemistry and diagenesis of Miocene lacustrine siliceous <span class="hlt">sedimentary</span> and pyroclastic rocks, Mytilinii <span class="hlt">basin</span>, Samos Island, Greece</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stamatakis, M.G.; Hein, J.R.; Magganas, A.C.</p> <p>1989-01-01</p> <p>A Late Miocene non-marine stratigraphic sequence composed of limestone, opal-CT-bearing limestone, porcelanite, marlstone, diatomaceous marlstone, dolomite, and tuffite crops out on eastern Samos Island. This lacustrine sequence is subdivided into the Hora Beds and the underlying Pythagorion Formation. The Hora Beds is overlain by the clastic Mytilinii series which contains Turolian (Late Miocene) mammalian fossils. The lacustrine sequence contains volcanic glass and the silica polymorphs opal-A, opal-CT, and quartz. Volcanic glass predominantly occurs in tuffaceous rocks from the lower and upper parts of the lacustrine sequence. Opal-A (diatom frustules) is confined to layers in the upper part of the Hora Beds. Beds rich in opal-CT underlie those containing opal-A. The occurrence of opal-CT is extensive, encompassing the lower Hora Beds and the <span class="hlt">sedimentary</span> rocks and tuffs of the Pythagorion Formation. A transition zone between the opal-A and opal-CT zones is identified by X-ray diffraction patterns that are intermediate between those of opal-CT and opal-A, perhaps due to a mixture of the two polymorphs. Diagenesis was not advanced enough for opal-CT to transform to quartz or for volcanic glass to transform to opal-C. Based on geochemical and mineralogical data, we suggest that the rate of diagenetic transformation of opal-A to opal-CT was mainly controlled by the chemistry of pore fluids. Pore fluids were characterized by high salinity, moderately high alkalinity, and high magnesium ion activity. These pore fluid characteristics are indicated by the presence of evaporitic salts (halite, sylvite, niter), high boron content in biogenic silica, and by dolomite in both the opal-A and opal-CT-bearing beds. The absence of authigenic K-feldspar, borosilicates, and zeolites also support these pore fluid characteristics. Additional factors that influenced the rate of silica diagenesis were host rock lithology and the relatively high heat flow in the Aegean region from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.U62A..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.U62A..08C"><span>Flow-Through, Low Retention Hydrocarbon Generation in Active <span class="hlt">Sedimentary</span> <span class="hlt">Basins</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cathles, L. M.</p> <p>2002-12-01</p> <p>Hydrocarbons are typically generated when thin (<100 m), organic-rich strata are buried. Oil is generated first, then gas. Detailed investigation of the chemistry of hydrocarbons in a 100 (E-W) x 200 (N-S) km study area in the offshore Louisiana Gulf of Mexico <span class="hlt">Basin</span> shows that the early-generated oils there have been extensively altered by interaction with late-generated gas, producing a remarkably regular pattern in which over 90 wt% of the n-alkanes have been removed by gas washing in the north while none have been so removed in the south. Straight-forward (Turcottian) physical-chemical modeling suggests this pattern can be produced only if the retention of hydrocarbons between source and seafloor is very low (0.1% of the pore space). This low retention means that about 80% or 120 billion tones (Bt) of the ~149 Bt of hydrocarbons that have been generated and expelled from the source strata in the study area have been vented into the ocean. This mass of vented hydrocarbons is 100 times the mass of hydrocarbon in known reservoirs in the area (1.4 Bt or 11 billon barrels of oil and gas equivalent). The reservoired hydrocarbons are about 5% of the hydrocarbons retained in the models between the source and seafloor. To be properly washed, the reservoired hydrocarbons must also have been very recently introduced. The hydrocarbon system in the study area is thus one of massive venting with minor, constantly replenished (flow through) retention. The predicted current rates of venting are confirmed by independent estimates of the rate of hydrate accumulation in the southern part of the study area. The massive venting of over 900 billion barrels (equivalent) of hydrocarbons, an amount about equal to the total world consumption of oil to date, from a 100 x 200 km portion of one <span class="hlt">basin</span> in a relatively short timespan (about 20 Ma) provides an interesting geologic context for human production and consumption. The rapid venting also has potentially important implications for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJWC.14012009G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJWC.14012009G"><span>Are polygonal faults the keystone for better understanding the timing of fluid migration in <span class="hlt">sedimentary</span> <span class="hlt">basins</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gay, Aurélien</p> <p>2017-06-01</p> <p>The initial sediment lithification starts with complex interactions involving minerals, surface water, decomposing organic matter and living organisms. This is the eogenesis domain (0 to 2 km below the seafloor) in which the sediments are subject to physical, chemical and mechanical transformations defining the early fabric of rocks. This interval is intensively prospected for its energy/mining resources (hydrocarbons, metal deposits, geothermal energy). In most <span class="hlt">basins</span> worldwide it is composed of very fine-grained sediments and it is supposed to play the role of a seal for fluids migration. However, it is affected by polygonal faulting due to a volume loss during burial by contraction of clay sediments with a high smectite content. This process is of high interest for fractured reservoirs and/or cover integrity but it is not well constrained giving an uncertainty as this interval can either promote the migration of deeper fluids and the mineralized fluids intensifies diagenesis in the fracture planes, rendering this interval all the more impermeable. The next challenge will be to define where, when and how does this polygonal fault interval occur and this can only be done by understanding the behavior of clay grains and fluids during early burial.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6130082','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6130082"><span>Cementation and compaction history of synorogenic foreland <span class="hlt">basin</span> <span class="hlt">sedimentary</span> rocks from Huaco, Argentina</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Damanti, J.F.; Jordan, T.E.</p> <p>1989-07-01</p> <p>The Sierra de Huaco exposes the western flank of the Bermejo foreland <span class="hlt">basin</span> of central western Argentina. The exposed 5400-m section is well dated (14-2.3 Ma) and consists of synorogenic continental strata. Petrographic data combined with decompaction techniques provide first-order estimates of the absolute age of cementation of the sandstones. This information can be used to interpret petroleum migration paths and reservoir potential. Three diagenetic zones have been recognized, each characterized by a dominant cementing material within a distinct framework texture. These textures reflect varying degrees of compaction and framework-grain replacement prior to cementation. The diagenetic histories of the three zones were genetically linked to thrusting in the adjacent Precordillera, changes in depositional environment, and subsurface fluid flow. The depth at which cementation occurred in each zone is constrained by comparison of observed intergrain volume to predicted volumes (for uncemented sands) at any given burial depth. First-order estimates of the absolute age of cementation in each zone were made possible by comparing these relationships with a curve of accumulation history of the decompacted strata. The lowest zone compacted with little interstitial cement for as long as 11 m.y. after deposition. The middle zone was cemented within 3 m.y. after deposition. The upper zone experienced framework-grain replacement by calcite at very shallow depths within 2 m.y. and experienced little compaction. 14 figures, 1 table.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.P44B..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.P44B..03S"><span><span class="hlt">Large</span> Impact <span class="hlt">Basin</span> Morphologies on Vesta in Solar System Context</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schenk, P.; O'Brien, D. P.; Marchi, S.; Sykes, M. V.; Williams, D. A.; Gaskell, R. W.; Jaumann, R.; McCord, T. B.; Russell, C. T.</p> <p>2012-12-01</p> <p>Dawn global imaging and topographic mapping (@ 20-70 m scales) reveals that the 505-km-wide impact <span class="hlt">basin</span> Rheasilvia has a <span class="hlt">large</span> central complex, steep rim scarp and bowl-shaped floor, elements similar to <span class="hlt">large</span> impact <span class="hlt">basins</span> on midsize icy satellites of Saturn. Impact melt and debris volumes are generally lower on Vesta and on icy satellites than on lunar <span class="hlt">basins</span>. These similarities suggest that the Rheasilvia morphology may be a consequence of <span class="hlt">large</span> impacts into lower gravity objects. Lower impact velocities and planetary curvature may also be important. Low melt volumes are consistent with predictions based on lower impact velocities on Vesta. Rheasilvia ejecta deposits extend over 100-150 km from the rim, and generally appear to scale similarly on Vesta and the Moon. Rheasiliva ejecta covers at least all of the southern hemisphere and may be more than 5 km thick near the rim. Oddly, the compositional feature associated with Rheasilvia is offset from its center by more than 100 km. A number of pre-Rheasilvia impact <span class="hlt">basins</span> are mapped, including several <span class="hlt">large</span> structures near the north pole. Most are degraded and original morphologies may be difficult to determine. Rheasilvia partially obliterated the older 400-km-wide 10-km-deep Veneneia <span class="hlt">basin</span>, the interior of which is highly disrupted. The next largest <span class="hlt">basin</span>, ~250-km-across is also old and heavily cratered. If it ever possessed a central peak, it has since been obliterated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAfES.129..260M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAfES.129..260M"><span>Sedimentology and paleoenvironments of a new fossiliferous late Miocene-Pliocene <span class="hlt">sedimentary</span> succession in the Rukwa Rift <span class="hlt">Basin</span>, Tanzania</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mtelela, Cassy; Roberts, Eric M.; Hilbert-Wolf, Hannah L.; Downie, Robert; Hendrix, Marc S.; O'Connor, Patrick M.; Stevens, Nancy J.</p> <p>2017-05-01</p> <p>This paper presents a detailed sedimentologic investigation of a newly identified, fossiliferous Late Neogene <span class="hlt">sedimentary</span> succession in the Rukwa Rift <span class="hlt">Basin</span>, southwestern Tanzania. This synrift deposit is a rare and significant new example of a fossiliferous succession of this age in the Western Branch of East Africa Rift System. The unit, informally termed the lower Lake Beds succession, is late Miocene to Pliocene in age based on cross-cutting relationships, preliminary biostratigraphy, and U-Pb geochronology. An angular unconformity separates the lower Lake Beds from underlying Cretaceous and Oligocene strata. Deposition was controlled by rapid generation of accommodation space and increased sediment supply associated with late Cenozoic tectonic reactivation of the Rukwa Rift and synchronous initiation of the Rungwe Volcanic Centre. The lower Lake Beds, which have thus far only been identified in three localities throughout the Rukwa Rift <span class="hlt">Basin</span>, are characterized by two discrete lithologic members (herein A and B). The lower Member A is a volcanic-rich succession composed mostly of devitrified volcanic tuffs, and volcaniclastic mudstones and sandstones with minor conglomerates. The upper Member B is a siliciclastic-dominated succession of conglomerates, sandstones, mudstones and minor volcanic tuffs. Detailed facies analysis of the lower Lake Beds reveals various distinctive depositional environments that can be grouped into three categories: 1) alluvial fan; 2) fluvial channel; and 3) flood <span class="hlt">basin</span> environments, characterized by volcanoclastic-filled lakes and ponds, abandoned channel-fills and pedogenically modified floodplains. Member A represents a shallow lacustrine setting filled by tuffaceous sediments, which grade up into a system of alluvial fans and high-energy, proximal gravel-bed braided rivers. An unconformity marks the contact between the two members. Member B shows an upward transition from a high-energy, gravel-bed braided river system to a sandy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1111859B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1111859B"><span>Ejected <span class="hlt">Sedimentary</span> Rocks of Mud Volcanoes as Indicators of Depositional Environments and of Hydrocarbon Generation within the South Caspian <span class="hlt">Basin</span>, Azerbaijan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berner, U.; Scheeder, G.; Kus, J.; Köthe, A.; Movsumova, U.</p> <p>2009-04-01</p> <p>Mud volcanoes are prominent geological features of the South Caspian <span class="hlt">Basin</span> of Azerbaijan, one of the oldest oil producing regions worldwide. The <span class="hlt">basin</span> is characterized by extreme sedimentation rates, which lead to the accumulation of <span class="hlt">large</span> volumes of Mesozoic and Cenozoic sediments. These mostly unconsolidated strata reach thicknesses of up to 20 km and overlay a continental basement in the onshore part. Tectonic forces control the occurrences of mud volcanoes in regions with over-pressured subsurface sediments as mud volcanoes are closely linked to fault systems. The mud volcanoes of Azerbaijan are a surface expression of vertical hydrocarbon migration and offer the chance to investigate the subsurface by means of ejected rocks transported to the surface. These rocks of Mesozoic and Cenozoic <span class="hlt">sedimentary</span> sequences are potential indicators of the regional hydrocarbon generation. The mud of nineteen volcano cones contained numerous ejected rock fragments, which we use to identify environmental and depositional parameters of the sediments of the Caspian <span class="hlt">Basin</span>. We also intended to estimate the depth range from which the mud was transported to the surface using organic geochemical parameters. Mircopalaeontological investigations (calcareous nannoplankton) have been performed on selected samples. These analyses suggest that the investigated sediments are of Late Cretaceous to Palaeogene ages and relate to the stratigraphic interval during which the main hydrocarbon source rocks of Azerbaijan have been deposited. Organic geochemical, organic petrographical and mircopalaeontological investigations have been performed on selected samples of nineteen mud volcanoes. Analyses total organic carbon and total sulphur were performed on an elemental analyzer. These analyses suggest that the sediments can be classified as anoxic marine deposits whereas only few are sediments of a lacustrine environment. Bulk source rock information were obtained from RockEval pyrolysis. Resulting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.T41E2983Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.T41E2983Z"><span>Modeling the <span class="hlt">Sedimentary</span> Infill of Lakes in the East African Rift: A Case Study of Multiple versus Single Rift <span class="hlt">Basin</span> Segments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, C.; Scholz, C. A.</p> <p>2016-12-01</p> <p>The <span class="hlt">sedimentary</span> <span class="hlt">basins</span> in the East African Rift are considered excellent modern examples for investigating <span class="hlt">sedimentary</span> infilling and evolution of extensional systems. Some lakes in the western branch of the rift have formed within single-segment systems, and include Lake Albert and Lake Edward. The largest and oldest lakes developed within multi-segment systems, and these include Lake Tanganyika and Lake Malawi. This research aims to explore processes of erosion and <span class="hlt">sedimentary</span> infilling of the catchment area in single-segment rift (SSR) and multi-segment rift (MSR) systems. We consider different conditions of regional precipitation and evaporation, and assess the resulting facies architecture through forward modeling, using state-of-the-art commercial <span class="hlt">basin</span> modeling software. Dionisos is a three-dimensional numerical stratigraphic forward modeling software program, which simulates <span class="hlt">basin</span>-scale sediment transport based on empirical water- and gravity-driven diffusion equations. It was classically used to quantify the <span class="hlt">sedimentary</span> architecture and <span class="hlt">basin</span> infilling of both marine siliciclastic and carbonate environments. However, we apply this approach to continental rift <span class="hlt">basin</span> environments. In this research, two scenarios are developed, one for a MSR and the other for a SSR. The modeled systems simulate the ratio of drainage area and lake surface area observed in modern Lake Tanganyika and Lake Albert, which are examples of MSRs and SSRs, respectively. The main parameters, such as maximum subsidence rate, water- and gravity-driven diffusion coefficients, rainfall, and evaporation, are approximated using these real-world examples. The results of 5 million year model runs with 50,000 year time steps show that MSRs are characterized by a deep water lake with relatively modest sediment accumulation, while the SSRs are characterized by a nearly overfilled lake with shallow water depths and thick sediment accumulation. The preliminary modeling results conform to the features</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeCoA.192...49S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeCoA.192...49S"><span>Impact of cable bacteria on <span class="hlt">sedimentary</span> iron and manganese dynamics in a seasonally-hypoxic marine <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sulu-Gambari, Fatimah; Seitaj, Dorina; Behrends, Thilo; Banerjee, Dipanjan; Meysman, Filip J. R.; Slomp, Caroline P.</p> <p>2016-11-01</p> <p>Cable bacteria have recently been identified in various <span class="hlt">sedimentary</span> marine settings worldwide. These filamentous microbes mediate electrogenic sulphur oxidation (e-SOx) over centimetre-scale distances, leading to a distinct separation of oxygen- and sulphide-bearing sediment zones. Here we present results of a year-long monthly assessment of the impact of cable bacteria on <span class="hlt">sedimentary</span> Fe and Mn dynamics at three sites located along a water depth gradient in a seasonally-hypoxic coastal marine lake (Grevelingen, The Netherlands). Fluorescence In Situ Hybridisation (FISH) shows the presence of cable bacteria at two sites in spring. Micro-sensor profiling (O2, pH, H2S) and pore water profiles of dissolved Mn, Fe2+, Ca2+ and SO42- reveal the geochemical signature of e-SOx at these sites, i.e. the development of a broad suboxic zone, characterised by a low pH and acidic dissolution of Ca/Mn carbonates and Fe sulphides. Cable bacteria activity, as reflected by dissolution of FeS in spring, was highest at the deepest and most hypoxic site. In spring, dissolved Mn and Fe2+ released at depth due to e-SOx diffused upwards and was sequestered as Mn- and Fe-(oxyhydr)oxides near the sediment surface, with Mn oxides acting as an oxidant for part of the upward diffusing Fe2+. Strikingly, the thickness of the Fe-(oxyhydr)oxide-bearing surface layer of the sediment was greatest at the most hypoxic site, emphasising the key role of cable bacteria in creating oxidised surface sediments. X-ray absorption fine structure analyses confirm the seasonality in Fe-(oxyhydr)oxide formation and reveal that the sediment Mn oxides were of biogenic (birnessite) and abiotic (hausmannite) origin. Upon the onset of hypoxia in early summer, the sediment Fe-(oxyhydr)oxides were mostly converted to Fe-sulphides but the Mn oxides dissolved and the Mn was lost to the overlying water. After summer hypoxia, Beggiatoaceae mats colonised the sediment with little further change in sediment geochemistry. Our</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H11J..06T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H11J..06T"><span>A Hydraulic Tomography Experiment in Fractured <span class="hlt">Sedimentary</span> Rocks, Newark <span class="hlt">Basin</span>, New Jersey, USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tiedeman, C. R.; Barrash, W.; Thrash, C. J.; Johnson, C. D.</p> <p>2015-12-01</p> <p>Hydraulic tomography was performed in July 2015 in contaminated fractured mudstone beds at the former Naval Air Warfare Center (NAWC) in the Newark <span class="hlt">Basin</span> near Trenton, NJ using seven existing wells. The spatial arrangement of wells (in a circle of 9 m radius with one central well), the use of packers to divide the wells into multiple monitoring intervals, and the deployment of fiber optic pressure transducers enabled collection of a hydraulic tomography dataset comprising high-resolution drawdown observations at an unprecedented level of spatial detail for fractured rocks. The experiment involved 45-minute cross-hole aquifer tests, conducted by pumping from a given packer-isolated well interval and continuously monitoring drawdowns in all other well intervals. The collective set of drawdown data from all tests and intervals displays a wide range of behavior suggestive of highly heterogeneous hydraulic conductivity (K) within the tested volume, such as: drawdown curves for different well intervals crossing one another on drawdown-time plots; variable drawdown curve shapes, including linear segments on log-log plots; variable order and magnitude of time-lag and/or drawdown for intervals of a given well in response to pumping from similar fractures or stratigraphic units in different wells; and variable groupings of wells and intervals showing similar responses for different pumping tests. The observed behavior is consistent with previous testing at the NAWC indicating that K within and across individual mudstone beds can vary by orders of magnitude over scales of meters. Preliminary assessment of the drawdown data together with a rich set of geophysical logs suggests an initial conceptual model that includes densely distributed fractures of moderate K at the shallowest depths of the tested volume, connected high-K bedding-plane-parting fractures at intermediate depths, and sparse low-K fractures in the deeper rocks. Future work will involve tomographic inversion of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007EM%26P..101..153B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007EM%26P..101..153B"><span>A <span class="hlt">Large</span> <span class="hlt">Basin</span> on the Near Side of the Moon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Byrne, Charles Joseph</p> <p>2007-12-01</p> <p>The differences between the surface structure of the near side and the far side of the Moon have been topics of interest ever since photographs of the far side have been available. One recurrent hypothesis is that a <span class="hlt">large</span> impact on the near side has deposited ejecta on the far side, resulting in thicker crust there. Specific proposals were made by P.H. Cadogan for the Gargantuan <span class="hlt">Basin</span> and by E.A. Whitaker for the Procellarum <span class="hlt">Basin</span>. Despite considerable effort, no consensus has been reached on the existence of these <span class="hlt">basins</span>. The problem of searching for such a <span class="hlt">basin</span> is one of finding its signature in a somewhat chaotic field of <span class="hlt">basin</span> and crater impacts. The search requires a model of the topographic shape of an impact <span class="hlt">basin</span> and its ejecta field. Such a model is described, based on elevation data of lunar <span class="hlt">basins</span> collected by the Lidar instrument of the Clementine mission and crustal thickness data derived from tracking Clementine and other spacecraft. The parameters of the model are scaled according to the principles of dimensional analysis and isostatic compensation in the early Moon. The orbital dynamics of the ejecta and the curvature of the Moon are also taken into account. Using such a scaled model, a search for the best fit for a <span class="hlt">large</span> <span class="hlt">basin</span> led to identification of a <span class="hlt">basin</span> whose cavity covers more than half the Moon, including the area of all of the impact <span class="hlt">basins</span> visible on the near side. The center of this <span class="hlt">basin</span> is at 22 degrees east longitude and 8.5 degrees north latitude and its average radius is approximately 3,160 km. It is a megabasin, a <span class="hlt">basin</span> that contains other <span class="hlt">basins</span> (the far side South Pole-Aitken <span class="hlt">Basin</span> also qualifies for that designation). It has been called the Near Side Megabasin. Much of the material ejected from the <span class="hlt">basin</span> escaped the Moon, but the remainder formed an ejecta blanket that covered all of the far side beyond the <span class="hlt">basin</span> rim to a depth of from 6 to 30 km. Isostatic compensation reduced the depth relative to the mean surface to a range</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/543079','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/543079"><span><span class="hlt">Sedimentary</span> record and climatic implications of recurrent deformation in the Tian Shan: Evidence from Mesozoic strata of the north Tarim, south Junggar, and Turpan <span class="hlt">basins</span>, northwest China</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hendrix, M.S.; Graham, S.A.; Sobel, E.R.</p> <p>1992-01-01</p> <p>Detailed stratigraphic, sedimentologic, paleocurrent, and subsidence analyses were conducted on Mesozoic nonmarine <span class="hlt">sedimentary</span> sections of the south Junggar, north Tarim, and Turpan <span class="hlt">basins</span>, Xinjang Uygur Autonomous Region, northwest China. These three <span class="hlt">basins</span> have been foreland <span class="hlt">basins</span> throughout the Mesozoic and Cenozoic eras, as demonstrated by asymmetrically distributed basinwide sediment accumulations, foreland-style subsidence profiles, and a variety of outcrop and subsurface facies data. Mesozoic paleocurrent indicators measured in the south Junggar and north Tarim <span class="hlt">basins</span>, as well as Mesozoic sandstone compositions from both <span class="hlt">basins</span>, indicate that the intervening Tian Shan has existed as a positive physiographic feature partitioning the two <span class="hlt">basins</span> throughout Mesozoic and Cenozoic time. Paleocurrent, facies, and subsurface isopach data suggest that the Turpan <span class="hlt">basin</span> was established as a discrete feature by the Early Jurassic period. The timing and style of depositional systems within the north Tarim Mesozoic depocenter, the south Junggar Mesozoic depocenter, and the central Turpan <span class="hlt">basin</span> are remarkably similar. Upper Triassic strata of each <span class="hlt">basin</span> consist of alluvial conglomerate and associated braided-fluvial sandstone and siltstone which fine upward into lower through Middle Jurassic, locally organic-rich, meandering-fluvial, and lacustrine strata. Upper Jurassic braided-fluvial red beds in each <span class="hlt">basin</span> are overlain by a distinct pulse of uppermost Jurassic alluvial conglomerate. Lower Cretaceous exposures consist of fine-grained red beds in north Tarim and Turpan and interbedded red and gray shale with local silty carbonates in south Junggar. Upper Cretaceous strata of the north Tarim and south Junggar <span class="hlt">basins</span> are composed of alluvial conglomerate with associated braided-fluvial sandstone and siltstone. 94 refs., 17 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC23A1125L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC23A1125L"><span><span class="hlt">Large</span>-scale Modeling of Inundation in the Amazon <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, X.; Li, H. Y.; Getirana, A.; Leung, L. R.; Tesfa, T. K.</p> <p>2015-12-01</p> <p>Flood events have impacts on the exchange of energy, water and trace gases between land and atmosphere, hence potentially affecting the climate. The Amazon River <span class="hlt">basin</span> is the world's largest river <span class="hlt">basin</span>. Seasonal floods occur in the Amazon <span class="hlt">Basin</span> each year. The <span class="hlt">basin</span> being characterized by flat gradients, backwater effects are evident in the river dynamics. This factor, together with <span class="hlt">large</span> uncertainties in river hydraulic geometry, surface topography and other datasets, contribute to difficulties in simulating flooding processes over this <span class="hlt">basin</span>. We have developed a <span class="hlt">large</span>-scale inundation scheme in the framework of the Model for Scale Adaptive River Transport (MOSART) river routing model. Both the kinematic wave and the diffusion wave routing methods are implemented in the model. A new process-based algorithm is designed to represent river channel - floodplain interactions. Uncertainties in the input datasets are partly addressed through model calibration. We will present the comparison of simulated results against satellite and in situ observations and analysis to understand factors that influence inundation processes in the Amazon <span class="hlt">Basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SedG..197..127Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SedG..197..127Y"><span>Geochemistry of the <span class="hlt">sedimentary</span> rocks from the Nanxiong <span class="hlt">Basin</span>, South China and implications for provenance, paleoenvironment and paleoclimate at the K/T boundary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, Yi; Xia, Bin; Lin, Ge; Cui, Xuejun; Hu, Xiaoqiong; Yan, Pin; Zhang, Faqiang</p> <p>2007-04-01</p> <p>Cretaceous and Tertiary clastic <span class="hlt">sedimentary</span> rocks from the Nanxiong <span class="hlt">Basin</span>, South China have been analyzed to constrain their provenance, depositional climate and environment. Evidence from discrimination diagrams for <span class="hlt">sedimentary</span> provenance and tectonic setting show that the Nanxiong <span class="hlt">Basin</span> sediments were derived from typical continental sources. Geochemical signatures (e.g. Eu/Eu *, Th/Ti, La/Ti, Ta/Ti, Yb/Ti and Y/Ti ratios of the claystone) are nearly constant, suggesting the provenance of the Nanxiong <span class="hlt">Basin</span> remained similar throughout the Late Cretaceous to Early Paleocene (83-56 Ma). In contrast Rb/Ti, Cs/Ti ratios and TOC and CaCO 3 concentrations require an obvious change in climate across the Late Cretaceous and Early Paleocene boundary. Singularly higher CaCO 3 contents and lower TOC values and Rb/Ti, Cs/Ti ratios in the Late Cretaceous indicate that a long period extreme dry climate occurred at that time in South China. Rb/Ti, Cs/Ti ratios and TOC values escalated and CaCO 3 contents decreased in the Early Paleocene suggesting that the climate became relatively wet, which resulted in greater vegetation cover. The lasting extreme dry climate in the Late Cretaceous may provide a clue to the extinction of the dinosaurs in the Nanxiong <span class="hlt">Basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PEPI..169..131L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PEPI..169..131L"><span>Morphology of the Iceland <span class="hlt">Basin</span> Excursion from a spherical harmonics analysis and an iterative Bayesian inversion procedure of <span class="hlt">sedimentary</span> records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lanci, Luca; Kissel, Catherine; Leonhardt, Roman; Laj, Carlo</p> <p>2008-08-01</p> <p>Based on 5 published marine high-resolution <span class="hlt">sedimentary</span> records of the Iceland <span class="hlt">Basin</span> Excursion [IBE; Channell, J.E.T., Hodell, D.A., Lehman, B., 1997. Relative geomagnetic paleointensity and ∂ 18O at ODP Site 983/Gardar Drift, North Atlantic since 350 ka. Earth Planet. Sci. Lett. 153, 103-118; Laj, C., Kissel, C., Roberts, A., 2006. Geomagnetic field behavior during the Iceland <span class="hlt">Basin</span> and Laschamp geomagnetic excursions: a simple transitional field geometry? Geochem. Geophys. Geosystems. 7, Q03004, doi:10.1029/2005GC001122] dated around 186-190 kyr, we present models of the excursional geomagnetic field at the Earth's surface using two different approaches. First a spherical harmonics analysis is performed after synchronization of the records using their paleointensity profiles. Second, we have used an iterative Bayesian inversion procedure, calibrated using the single volcanic data available so far. Both modeling approaches suffer from imperfections of the paleomagnetic signals and mostly from the still poor geographical distribution of detailed records, presently available only from the North Atlantic and the West Pacific. For these reasons, our modeling results should only be regarded as preliminary models of the geomagnetic field during the IBE, susceptible to improvements when including results from future paleomagnetic studies. Nevertheless, both approaches show distinct similarities and are stable against moderate variations of modeling parameters. The general picture is that of a dipole field undergoing a strong reduction, but remaining higher than the non-dipole field all through the excursional process, except for a very short interval of time corresponding to the dipole minimum at the center of the excursion. On the other hand, some differences exist between the results of the two models with each other and with the real data when the virtual geomagnetic pole (VGP) paths are considered. The non-dipole field does not appear to undergo very significant</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993JAfES..16..143S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993JAfES..16..143S"><span>A review of the stratigraphy and <span class="hlt">sedimentary</span> environments of the Karoo-aged <span class="hlt">basins</span> of Southern Africa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, R. M. H.; Eriksson, P. G.; Botha, W. J.</p> <p>1993-02-01</p> <p>The Karoo <span class="hlt">Basin</span> of South Africa was one of several contemporaneous intracratonic <span class="hlt">basins</span> in southwestern Gondwana that became active in the Permo-Carboniferous (280 Ma) and continued to accumulate sediments until the earliest Jurassic, 100 million years later. At their maximum areal extent, during the early Permian, these <span class="hlt">basins</span> covered some 4.5 million km 2. The present outcrop area of Karoo rocks in southern Africa is about 300 000 km 2 with a maximum thickness of some 8000 m. The economic importance of these sediments lies in the vast reserves of coal within the Ecca Group rocks of northern and eastern Transvaal and Natal, South Africa. <span class="hlt">Large</span> reserves of sandstone-hosted uranium and molybdenum have been proven within the Beaufort Group rocks of the southern Karoo trough, although they are not mineable in the present market conditions. Palaeoenvironmental analysis of the major stratigraphic units of the Karoo succession in South Africa demonstrates the changes in depositional style caused by regional and localized tectonism within the <span class="hlt">basin</span>. These depocentres were influenced by a progressive aridification of climate which was primarily caused by the northward drift of southwestern Gondwana out of a polar climate and accentuated by the meteoric drying effect of the surrounding land masses. Changing palaeoenvironments clearly influenced the rate and direction of vertebrate evolution in southern Gondwana as evidenced by the numerous reptile fossils, including dinosaurs, which are found in the Karoo strata of South Africa, Lesotho, Namibia and Zimbabwe. During the Late Carboniferous the southern part of Gondwana migrated over the South Pole resulting in a major ice sheet over the early Karoo <span class="hlt">basin</span> and surrounding highlands. Glacial sedimentation in upland valleys and on the lowland shelf resulted in the Dwyka Formation at the base of the Karoo Sequence. After glaciation, an extensive shallow sea covered the gently subsiding shelf, fed by <span class="hlt">large</span> volumes of meltwater</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Icar..264..331B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Icar..264..331B"><span>A global survey of martian central mounds: Central mounds as remnants of previously more extensive <span class="hlt">large</span>-scale <span class="hlt">sedimentary</span> deposits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bennett, Kristen A.; Bell, James F.</p> <p>2016-01-01</p> <p>We conducted a survey of central mounds within <span class="hlt">large</span> (>25 km diameter) impact craters on Mars. We use mound locations, mound offsets within their host craters, and relative mound heights to address and extend various mound formation hypotheses. The results of this survey support the hypothesis that mound sediments once filled their host craters and were later eroded into the features we observe today. The majority of mounds are located near the boundaries of previously identified <span class="hlt">large</span>-scale <span class="hlt">sedimentary</span> deposits. We discuss the implications of the hypothesis that central mounds are part of previously more extensive <span class="hlt">sedimentary</span> units that filled and overtopped underlying impact craters. In this scenario, as erosion of the <span class="hlt">sedimentary</span> unit occurred, the sediment within impact craters was preserved slightly longer than the overlying sediment because it was sheltered by the crater walls. Our study also reveals that most mounds are offset from the center of their host crater in the same direction as the present regional winds (e.g., the mounds in Arabia Terra are offset towards the western portion of their craters). We propose that this implies that wind has been the dominant agent causing the erosion of central mounds. Mound offset (r) is normalized to each crater's radius. The Mound offset (θ) is such that 0 is north and 270 is west.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JSAES..28..180B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JSAES..28..180B"><span>Paleoenvironments and origin of the <span class="hlt">sedimentary</span> phosphorites of the Napo Formation (Late Cretaceous, Oriente <span class="hlt">Basin</span>, Ecuador)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brookfield, M. E.; Hemmings, D. P.; Van Straaten, P.</p> <p>2009-08-01</p> <p>The Napo phosphorites were deposited at the edge of a stable marine shelf during the Upper Cretaceous (Coniacian) oceanic anoxic event (OAE 3) at the transition from bioclastic limestone to organic-rich shale facies. Phosphogenesis was triggered in the shelf margin environment by a number of factors including strong upwelling currents, high biological activity, plankton blooms, and <span class="hlt">large</span> amounts of organic matter production and subsequent accumulation. Dissolved phosphate levels increased in the sediment from a combination of anoxic conditions and microbial activity. Once dissolved phosphate concentrations were high enough, apatite began to form around nucleic sites including mineral grains, shells, wood fragments, and foraminifera tests forming peloidal fluorine rich carbonate fluoroapatite (francolite). As the peloids formed, sedimentation continued and dissolved phosphate concentrations diminished. A period of minor winnowing ensued, and as dissolved phosphate concentrations remained low, shale layers were deposited separating the various phosphate layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H23D1221M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H23D1221M"><span><span class="hlt">Large</span> <span class="hlt">sedimentary</span> aquifer system and sustainable management: investigations of hydrogeological and geochemical variations in Eocene sand aquifer, south western France</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malcuit, E.; Negrel, P. J.; Petelet-Giraud, E.; Durst, P.</p> <p>2010-12-01</p> <p>In the <span class="hlt">sedimentary</span> Aquitaine <span class="hlt">Basin</span>, the Eocene Sand Aquifer system, mostly confined, represents strategic resources for drinking water, irrigation, gas storage and geothermal resources. Therefore, its quantity and quality issues are essential for the sustainable management in this <span class="hlt">large</span> region that extends over 116,000 km2 (i.e. one-fifth of the French territory). The Eocene Sand Aquifer system comprises at least five aquifers: Paleocene, Eocene infra-molassic sands, early Eocene, middle Eocene, and late Eocene. The extension and thickness of Eocene aquifer layers and negative confined layers vary throughout the <span class="hlt">basin</span>, from several tens of metres to a hundred metres. The deposit sequences characterizing the Eocene Aquifer System are progradational westward from detrital deposits to carbonates. Eocene sands and Eocene limestones are hydraulically connected and covered by an aquiclude of up to several hundred metres thick of molassic sediments. The groundwater recharge is assumed to occur through the Eocene outcrops located in the north and north-east, and in the south east in contact with the Montagne Noire as well as by vertical leakage from the upper and lower aquifers. Another recharge is suspected in the south near the Petites Pyrenees. According to isotopic data, both present-day recharge and old recharge (16-35 ky) can be evidenced. The north and south evolutions of the piezometric surface are different. In the north, because of years of pumping, a trough in the potentiometric surface has been formed. The piezometric decline is roughly one meter per year in the depression centre. In the south, the decline of the water table is roughly half a meter per year. Furthermore, in the south part, around two sites of gas storage, significant fluctuations of the potentiometric surface are superimposed to the variations resulting from water abstraction, due to the injection and abstraction of gas. However, a major difficulty for the sustainable management is the lack of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T31C1826B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T31C1826B"><span>Structural Evolution of a <span class="hlt">Large</span> Extensional <span class="hlt">Basin</span> Near Charleston, SC, Illuminated By Seismic-Reflection Profiling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beale, J. N.; Chapman, M. C.</p> <p>2009-12-01</p> <p>A comprehensive re-examination and reprocessing of 1980s-vintage seismic-reflection data collected near Charleston, South Carolina, which lies within the South Georgia Rift, has revealed evidence of significant crustal extension and coeval magmatic activity, as well as apparent <span class="hlt">basin</span> inversion and a late-stage episode of mafic volcanism. The South Georgia Rift is comprised of several <span class="hlt">large</span> extensional <span class="hlt">basins</span> separated by intervening structural highs, and is a failed Triassic-Jurassic rift separating the Appalachian Piedmont terrane to the north from the Suwannee terrane to the south. Gravity and magnetic modeling indicate that a significant amount of mafic rock lies within the upper crust near Charleston. Seismic profiles show bright reflections within the early-Mesozoic basement rock beneath the Atlantic Coastal Plain sediments that probably represent the interface between clastic sediments and basalt layers. These basalt layers have been sparsely sampled by deep drilling within the South Georgia Rift. The seismic data from Charleston, together with crustal scale, seismic-reflection data from Georgia, show the evolution of the rifting process from the extensional phase which produced the <span class="hlt">large</span> <span class="hlt">basins</span> and high rates of sedimentation, through the compressional phase which produced uplift and erosion leading to an inverted <span class="hlt">basin</span> geometry. Additionally, in the Charleston area, the seismic data show a basalt layer that forms the post-rift unconformity over most of the area. This basalt layer is not present on most of the profiles in Georgia, where the base of the coastal plain sediments is rift-related <span class="hlt">sedimentary</span> rock. Significantly, near Charleston this basalt layer lacks the <span class="hlt">large</span> amount of deformation that is characteristic of all of the imaged basalt layers beneath it. This suggests that there is a significant separation in time between the syn-rift basalt layers and the apparently post-rift basalt layer at the top of the rift sequence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997Tectp.271..191E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997Tectp.271..191E"><span>Structure and tectonic evolution of the Tornquist Zone and adjacent <span class="hlt">sedimentary</span> <span class="hlt">basins</span> in Scania and the southern Baltic Sea area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Erlström, M.; Thomas, S. A.; Deeks, N.; Sivhed, U.</p> <p>1997-04-01</p> <p>Southernmost Sweden, Bornholm and the surrounding Baltic Sea region are located on a <span class="hlt">large</span>-scale releasing bend in the dextral strike-slip system of the Tornquist Zone, with its resulting pull-apart <span class="hlt">basins</span>. The well constrained geology of Scania and Bornholm has been combined with detailed on- and offshore borehole data and three proprietary marine seismic surveys. This in conjunction with supplementary BABEL deep seismic reflection findings allows a combined 3D interpretation of sediment/structure interactions. As a result, a regional interpretation has emerged which gives a new understanding of the interplay between structural movement on a complex strike-slip fault system (Tornquist Zone) and its intrazonal depressions (Vomb Trough and Colonus Shale Trough) as well as the sedimentation history of associated areas of sediment accumulation (Rønne and Arnager Grabens, Höllviken Halfgraben, Hanö Bay <span class="hlt">Basin</span> and Skurup Platform). Detailed sequential litho- and seismo-stratigraphic descriptions have been possible by combination of the various data sets. This resulted in the clarification or recognition of previously unknown structural limits to sub-<span class="hlt">basins</span> and highs in the study area. A 3D chronological (4D) model for the development of the region is proposed. This model takes into account the long-lived structural history combining elements of strike-slip, extension and inversion tectonics. The deep-seated faulting controlling these structures is integrated with the deep structure as revealed by the BABEL line in this area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SedG..241...22S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SedG..241...22S"><span>Chronology and tectono-<span class="hlt">sedimentary</span> evolution of the Upper Pliocene to Quaternary deposits of the lower Guadalquivir foreland <span class="hlt">basin</span>, SW Spain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salvany, Josep Maria; Larrasoaña, Juan Cruz; Mediavilla, Carlos; Rebollo, Ana</p> <p>2011-11-01</p> <p>This paper presents new litho, chrono and magnetostratigraphic data from cores of 23 exploratory boreholes drilled in the Abalario and marshlands areas of the lower Guadalquivir <span class="hlt">basin</span> (the western sector of the Guadalquivir foreland <span class="hlt">basin</span>, SW of Spain). The lithologic logs of these boreholes identify four main <span class="hlt">sedimentary</span> formations, namely: Almonte Sand and Gravel, Lebrija Clay and Gravel, Marismas Clay and Abalario Sand, respectively interpreted as proximal-alluvial, distal-alluvial, alluvial-estuarine and aeolian. From radiocarbon and magnetostratigraphic data, these formations were dated as Upper Pliocene to Holocene. In the marshlands area, three main <span class="hlt">sedimentary</span> sequences are present: an Upper Pliocene to Lower Pleistocene sequence of the Almonte and Lebrija (lower unit) formations, a Pleistocene sequence of the Lebrija (upper unit) and the lower Marismas formations, and a latest Pleistocene to present-day sequence of the upper Marismas Formation. The three sequences began as a rapid alluvial progradation on a previously eroded surface, and a subsequent alluvial retrogradation. In the third sequence, estuarine and marsh sediments accumulated on top of the alluvial sediments. The aeolian sands of the Abalario topographic high developed coeval to alluvial and estuarine sedimentation after the first alluvial progradation, and continuously until the present. Correlation with the surrounding areas show that the sequences are the result of the forebulge uplift of the northern margin of the <span class="hlt">basin</span> (Sierra Morena) and the adjacent Neogene oldest sediments of their northern fringe, both form the main source area of the study formations. This uplift occurred simultaneous to the flexural subsidence (SSE tilting) of the southern part of the <span class="hlt">basin</span>, where <span class="hlt">sedimentary</span> aggradation dominated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5698862','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5698862"><span><span class="hlt">Sedimentary</span> architecture of marginal and shallow marine depositional systems tracts in upper Cretaceous series of San Juan <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nummedal, D. )</p> <p>1989-09-01</p> <p>The Upper Cretaceous series of the San Juan <span class="hlt">basin</span> consists of five (or more ) depositional sequences bounded partially by subaerial unconformities and partially by correlative, basinward conformities. Three depositional systems tracts account for nearly all the preserved strata: highstand, lowstand, and transgressive. At relative sea level highstand, sediments are accommodated at the most landward sites within the <span class="hlt">basin</span> (e.g., early Gallup Sandstone tongues). This systems tract is characterized by prograding bay-head deltas and successive open-marine deltas. During the ensuing sea level fall, much of the highstand system is removed by subaerial erosion. At relative sea level lowstand, sediments accumulate at the most <span class="hlt">basinal</span> sites in the form of prograding strand plains, associated shelf sand sheets and plumes, and a minor amount of fluvial channel and overbank deposits. During transgression the coastal plain is aggrading and hence traps most terrigenous clastics before they reach the open coast. The attendant erosional retreat of the shoreface, however, releases coarse sediment (sand) to the shelf, where it accumulates in <span class="hlt">large</span>-scale shelf sand ridges. These ridges are the principal petroleum reservoirs in the Cretaceous rocks of the <span class="hlt">basin</span> (Tocito Sandstone Lentil, parts of the Twowells Tongue of the Dakota Sandstone, etc.). During the transgression a carbonate-dominated condensed section encroaches landward, stratigraphically above the transgressive depositional systems. This surface attains its maximum landward extent some time between peak rate of sea level rise and highstand. The three principal surfaces of the depositional sequence - the sequence boundary, the transgressive ravinement surface, and the condensed section - all have clearly defined sedimentological characteristics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6849926','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6849926"><span>Mature area of new frontier Northeast British Columbia reveals new high potential in the structurally complex region of the western Canada <span class="hlt">sedimentary</span> <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hutton, A.N.; Varsek, J.L. )</p> <p>1993-09-01</p> <p>Northeast British Columbia has been extensively explored since the early fifties. Evaluated as a part of the Western Canada <span class="hlt">sedimentary</span> <span class="hlt">basin</span>, with a passive undeformed basement and only Laramide deformation, the <span class="hlt">basin</span> must be considered mature. Recent work involving detailed stratigraphic analysis, extensive field observations, potential field data analysis, and deep crustal reflection seismic work lead to an exciting new view of this portion of the Western Canada <span class="hlt">basin</span>. Situated over the middle Proterozoic continental margin, a complexly deformed and deeply truncated foreland forms a ramp against highly magnetic crystalline rocks. Dipping features within the Proterozoic intersect the Phanerozoic, producing local structure and uplift which has had a profound influence on Devonian reef paleogeography. A major contractional episode created previously unrecognized Devonian to Carboniferous folds and this discovery has led to a complete reinterpretation of the structural style and deformational history of the area. The structural complexity of the <span class="hlt">basin</span> is increased by right lateral strike-slip faulting. This system is highlighted in the subsurface by a series of faults fanning out across the <span class="hlt">basin</span> with displacements of up to 20 km in the Proterozoic foreland and accommodation continuing until the Cretaceous. Strike-slip deformation has generated an embayment in the Proterozoic continental margin and within the Phanerozoic shelf, indicating the occurrence of several previously unrecognized prospective shelf to <span class="hlt">basin</span> transitions. The complex interplay of structure and paleogeography results in a series of play opportunities that could result in new giant discoveries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9949T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9949T"><span>Integrated stratigraphy of the Smirra Coring: a new reference <span class="hlt">sedimentary</span> record for the early Paleogene from the Umbria-Marche <span class="hlt">Basin</span> (Northern Apennines, Italy)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turtù, Antonio; Lauretano, Vittoria; Catanzariti, Rita; Galeotti, Simone; Lanci, Luca; Moretti, Matteo; Lourens, Lucas J.</p> <p>2016-04-01</p> <p>The early Paleogene represents a critical time interval in Earth's history characterized by prolonged greenhouse conditions, culminating in a series of extreme global warming events (i.e. hyperthermals), as well as <span class="hlt">large</span> uncertainties in the Geological Time Scale. Therefore new, high-resolution, geological records are crucial in providing novel constraints on these topics. The Paleogene Umbria-Marche sections of the Northern Apennines (Italy) have shown to be suitable for integrated stratigraphy allowing regional-to-global correlations and environmental reconstructions across this time interval. Among several well-known sections, a new <span class="hlt">sedimentary</span> record is provided by the Smirra Coring, which recovered an undisturbed sequence of rocks (~120 m from 4 overlapping holes) spanning the upper Scaglia Fms. (early Paleocene - middle Eocene) of the Umbria-Marche pelagic succession. Here we present a new, high-resolution, integrated stratigraphic framework (magnetostratigraphy, calcareous nannofossil biostratigraphy, physical properties, calibrated XRF core scanning and cyclostratigraphy) of the ~93 m composite section drilled in Smirra Holes 1 and 2. The succession extends almost continuously, with modest tectonic disturbance affecting its lowermost part with minor faulting. The resulting magnetic stratigraphy defines a succession of normal and reversed polarity magnetozones. The correlation of the paleomagnetic polarity sequence with the latest Geomagnetic Polarity Timescales (GPTSs; e.g. CK95, GTS 2004 and 2012), also constrained through nannofossil biostratigraphy, shows that the section spans the late Paleocene - middle Eocene from chrons C21n (~46 Ma) to C26r (~60 Ma). The overall sedimentation rates computed at Smirra are fully comparable with those from coeval sections from the Umbria-Marche <span class="hlt">Basin</span>, ranging from ~10 m/Ma, between chrons C21n and C22n, to ~6 m/Ma, between chrons C22r and the base of the section. However, the sedimentation rates vary considerably</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ECSS..183..392L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ECSS..183..392L"><span><span class="hlt">Sedimentary</span> BSi and TOC quantifies the degradation of the Changjiang Estuary, China, from river <span class="hlt">basin</span> alteration and warming SST</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Maotian; Wang, Hong; Li, Yimiao; Ai, Wei; Hou, Lijun; Chen, Zhongyuan</p> <p>2016-12-01</p> <p>Environmental degradation in the Changjiang Estuary has recently become a global topic, given its proximity to Shanghai with a population >23 million. Intensification of human activities affecting the river <span class="hlt">basin</span> is responsible for this degradation. Dam construction has cut off ca. 2/3 of the sediment flux to the sea, ca. 60% of the dissolved silicate load (DSi) has been retained in the reservoirs, while total phosphorous (TP) and total nitrogen (TN) transport to the sea are many times more than they were a few decades ago. Under such circumstances, details of the estuarine degradation remain poorly understood. This study uses <span class="hlt">sedimentary</span> biological silicate (BSi) and total organic carbon (TOC) as environmental proxies to reveal the process-response of such degradation since the 1950s. Our results demonstrate the spatial differences of such degradation. The inner zone of the estuary used to be highly turbid, but presently has increasing diatom (BSi) and primary production (TOC), due to lower suspended sediment concentration (SSC) in relation to dam construction. In contrast, increasing riverine dissolved inorganic nitrate (DIN) and dissolved inorganic phosphorous (DIP) input (up to 2-5 times) and decreasing DSi provide a unique setting, with an excess in N and P, which catalyzes non-diatom algae in the less-turbid middle zone of the estuary. These are reflected by decreasing BSi and BSi/TOC since the 1950s, together with an increase of TOC of 20-40%. In the outer zone of the estuary, increasing DIN, DIP, and sea surface temperatures (SSTs), have resulted in the increase of diatom biomass by 15-20% and the growth of primary production by 30-60% since the 1950s. But the drastic decrease in DSi, Si/N, and Si/P depresses the ability of diatoms to develop, resulting in a reduction of 5-10% diatom proportion (BSi/TOC) since the 1930s. This study improves the understanding of the changing estuarine ecosystem in response to global change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....6144T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....6144T"><span>Analysing diagenetic effects of flood basalts on <span class="hlt">sedimentary</span> <span class="hlt">basins</span> during Gondwanan break-up: case studies from NW Namibia.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thompson, G. A.; Jerram, D. A.; Harris, C.; Pearson, D. G.</p> <p>2003-04-01</p> <p>ABSTRACT The eruption of <span class="hlt">large</span> volumes of lava associated with the break-up and dispersal of the Gondwana Supercontinent is a phenomenon that has been well documented in literature. The Etendeka Flood Basalt Province of NW Namibia is correlated with the Paraná Flood Basalt Province of South America and was extruded between 139Ma for the earliest flows and 130Ma for the most recent. The passive, inflated pahoehoe lava flows have preserved bedforms within sand dunes found in the Huab <span class="hlt">Basin</span> without significant deformation. This allows the internal structures of the palaeo-dunes to be analysed with great accuracy; a phenomenon rarely seen within the geological record. The sediments directly beneath, and interbedded with, the Etendeka Flood Basalt are lithostratigraphically similar to those in the Kudu Gas Province, offshore Namibia, where gas-bearing aeolian sands are interspersed with lava flows. Research by the authors is focussed on the diagenetic effects, both direct and indirect, of the emplacement of the lava, and the associated sills and dykes, on the aeolian sands. Specific interests include: the compartmentalisation of the <span class="hlt">basin</span> by sills/dykes/lava: how does this affect fluid flow paths? Diagenesis along hot contacts: is the dramatic reduction in porosity/permeability along such contacts the result of the igneous bodies alone or do they need ground water present? Can <span class="hlt">large</span> igneous events trigger the movement of hot fluids through the <span class="hlt">basin</span> and to what extent does this cause alteration to sediments? To address these issues we have identified a number of outcrop case studies within the Huab <span class="hlt">Basin</span> in NW Namibia. Here, excellent 3 dimensional outcrop coupled with almost 100 percent exposure allows detailed sampling strategies to be employed on locations of interest. In some cases igneous dykes have acted as flow barriers to pore fluids and have therefore altered the type and degree of cementation either side of the dyke. Geochemical analysis of the cement can</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H12C..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H12C..02B"><span>A Hypothetical Scenario for Full-Scale Deployment of Geological Carbon Sequestration: Investigating the Interaction Between Multiple CO2 Storage Sites in a <span class="hlt">Sedimentary</span> <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Birkholzer, J.; Zhou, Q.; Jordan, P.; Tsang, C.; Leetaru, H.; Mehnert, E.; Frailey, S.; Finley, R.</p> <p>2008-12-01</p> <p>Most ongoing projects of geological carbon sequestration (GCS) are relatively small in size, with annual injection rates from a few thousand to less than a million tonnes. These projects help build the GCS technology with respect to modeling, monitoring, risk assessment, and mitigation, and have been successful so far in terms of CO2 containment and caprock geomechanical integrity. In the future, GCS will be implemented at full-scale, multiple industrial-size CO2 storage sites in <span class="hlt">large</span> <span class="hlt">sedimentary</span> <span class="hlt">basins</span> to make full use of the potential storage capacity. Simultaneous injection into multiple not-too-distant storage sites will lead to interference between the individual regions of pressure build-up and possible interference between the individual CO2 plumes. The Illinois <span class="hlt">Basin</span> is used to model the future impact of multiple injection sites in the thick, extensive Mount Simon Formation. The <span class="hlt">basin</span>-scale model domain of 241,000 km2 covers a core injection area of 24,000 km2, a larger near-field area where significant pressure buildup is expected, and an even larger far-field area for investigating environmental impacts on groundwater resources. The model assumes that there are twenty sequestration sites (spaced 30 km apart) within the core injection area. Three injection scenarios are considered, featuring annual injection rates of 5, 10, and 15 million tonnes of CO2 at each site, respectively. These scenarios correspond to 33%, 67% and 100% of the current single-point <span class="hlt">large</span> CO2 sources in the relevant states (Illinois, Indiana and Kentucky). The model adequately captures the characteristics of the Mount Simon Formation in the core injection area, which include (1) an overall thickness of 300 to 680 m, (2) an upper unit of sandstone and shale tidally influenced and deposited, (3) a thick middle unit of clean sandstone of relatively high permeability, and (4) a lower arkosic unit of higher permeability (one Darcy) with an average thickness of 90 m. At each site, CO2 is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JAESc..67..171S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JAESc..67..171S"><span>Sequence stratigraphic significance of <span class="hlt">sedimentary</span> cycles and shell concentrations in the Aitamir Formation (Albian-Cenomanian), Kopet-Dagh <span class="hlt">Basin</span>, northeastern Iran</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharafi, M.; Mahboubi, A.; Moussavi-Harami, R.; Ashuri, M.; Rahimi, B.</p> <p>2013-05-01</p> <p>Albian-Cenomanian siliciclastic shallow marine sediments of the Aitamir Formation, Kopet-Dagh <span class="hlt">Basin</span>, northeastern Iran, form strongly asymmetric fining-coarsening-upward cycles, which are interpreted as recording changes in relative sea level (deepening-shallowing cycles). These cycles correspond to depositional sequences, in which deposits of the lowstand systems tract are not present, the sequence boundary coinciding with the transgressive surface. Shell concentrations are found in distinct positions within the depositional sequence: as transgressive lags at the base of the transgressive systems tract (TST), in the maximum flooding zone (MFZ), and at or close to the top of the highstand systems tract (HST). They are dominated by bivalves (mainly oysters) and/or ammonites and differ from each other in a number of stratigraphic, sedimentologic, palaeoecological and taphonomic features, such as species diversity, preservation quality, orientation, percentage of disarticulation, and degree of biogenic alteration. Characteristic features of concentrations at the base of the TSTs are moderate time-averaging, distinct basal erosional surface, sorting, a chaotic to preferred convex-up orientation, and nearly total disarticulation of shells. They are suggestive of an environment in which reworking and local transport was frequent events. Similar features are shown by concentrations near the tops of the HSTs, except that the shells were <span class="hlt">largely</span> concentrated in lenses rather than in beds as in the transgressive lags. Associated <span class="hlt">sedimentary</span> structures indicate deposition above fair weather wave base in a high-energy environment. Concentrations occurring in the MFZ, in contrast, are autochthonous and highly time-averaged, having accumulated during times of low rates of sedimentation below storm wave base. This is supported by their high preservation quality (comparatively high percentage of articulated shells, shells of infaunal organisms commonly preserved in life position</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21902029','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21902029"><span>Poyang Lake <span class="hlt">basin</span>: a successful, <span class="hlt">large</span>-scale integrated <span class="hlt">basin</span> management model for developing countries.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Meiqiu; Wei, Xiaohua; Huang, Hongsheng; Lü, Tiangui</p> <p>2011-01-01</p> <p>Protection of water environment while developing socio-economy is a challenging task for lake regions of many developing countries. Poyang Lake is the largest fresh water lake in China, with its total drainage area of 160,000 km2. In spite of rapid development of socio-economy in Poyang Lake region in the past several decades, water in Poyang Lake is of good quality and is known as the "last pot of clear water" of the Yangtze River <span class="hlt">Basin</span> in China. In this paper, the reasons of "last pot of clear water" of Poyang Lake were analysed to demonstrate how economic development and environmental protection can be coordinated. There are three main reasons for contributing to this coordinated development: 1) the unique geomorphologic features of Poyang Lake and the short water residence time; 2) the matching of the <span class="hlt">basin</span> physical boundary with the administrative boundary; and 3) the implementation of "Mountain-River-Lake Program" (MRL), with the ecosystem concept of "mountain as source, river as connection flow, and lake as storage". In addition, a series of actions have been taken to coordinate development, utilisation, management and protection in the Poyang Lake <span class="hlt">basin</span>. Our key experiences are: considering all <span class="hlt">basin</span> components when focusing on lake environment protection is a guiding principle; raising the living standard of people through implementation of various eco-economic projects or models in the <span class="hlt">basin</span> is the most important strategy; preventing soil and water erosion is critical for protecting water sources; and establishing an effective governance mechanism for <span class="hlt">basin</span> management is essential. This successful, <span class="hlt">large</span>-scale <span class="hlt">basin</span> management model can be extended to any <span class="hlt">basin</span> or lake regions of developing countries where both environmental protection and economic development are needed and coordinated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510879C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510879C"><span>Mantle-derived helium in <span class="hlt">sedimentary</span> <span class="hlt">basins</span> of Central Mediterranean: Geologic and tectonic constrains on fluids accumulation and migration.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caracausi, Antonio; Grassa, Fausto; Pennino, Valentina; Rizzo, Andrea; Sulli, Attilio</p> <p>2013-04-01</p> <p>The geodynamics of the central Mediterranean is characterized by the interaction between the European plate and the African one. In this setting Sicily is a sector of the Appenine-Maghrebide accretionary prism, which is located between two areas affected by extensional tectonics (Sicily Channel to the south and the Thyrrenian back arc <span class="hlt">basin</span> to the north). In the present study we present the first dataset of helium isotopic composition measured in fluids released from the central-western Sicily. With the aim to constrain the transfer system of fluids in this area we relate the results of geochemical investigations with the stratigraphy and structural setting, derived from field geology, deep boreholes and new seismic reflection, gravimetry and magnetometry data. Significant mantle-derived helium (0.4<R/Ra<2.8; R=3He/4He in the sample, Ra in atmosphere) is found in the CH4 and N2-CO2 rich fluids released in central western Sicily. CH4-dominated gases are released from mud volcanoes and feed everlasting fires mainly located in the central region, where upper Oligocene-Miocene terrigenous cover Mesozoic carbonatic units. The abundance of CH4, usually linked to the presence of hydrocarbons- and/or organic matter-rich layers, is almost exclusively linked to the Messinian evaporitic and pre-evaporitic levels (containing diatomites). On the other hand, CO2 is mainly associated to the thermal groundwaters circulating mainly in Mesozoic limestone and dolomite, which here constitute the bulk of the deformed wedge of the Sicilian chain (up to 15 km thick). In thermal waters, we found a positive correlation between water temperature, ranging between 22.1°C and 59°C, and helium isotopic ratio. Taking into consideration that helium rises from the mantle coupled to CO2 and others components, we discussed CO2 and CH4 coupled to helium. Our samples did no show any correlation between C/3He vs. R/Ra and only samples of the Sciacca thermal <span class="hlt">basin</span> show C/3He in the typical ranges of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914360M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914360M"><span>A Late-Glacial <span class="hlt">sedimentary</span> sequence at KIlkeel, Northern Ireland: implications for the glaciation of the Irish Sea <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Merritt, Jon; Roberson, Sam; Cooper, Mark</p> <p>2017-04-01</p> <p>This paper re-evaluates the nature and timing of a Late-Glacial ice sheet re-advance in the north western sector of the Irish Sea <span class="hlt">basin</span>. The <span class="hlt">sedimentary</span> archive in the region records the collapse of the Irish Sea Ice Stream, a major outlet glacier of the British-Irish Ice Sheet. The region documents the interplay between southerly flowing Scottish ice, ice flowing southeast from Lough Neagh and locally sourced Mournes ice. We present the results of sedimentological analysis of a glacigenic sequence exposed in a modern cliff section 3 km long between Derryoge and Kilkeel, Co. Down, Northern Ireland. The interaction between an advancing ice-sheet outlet lobe and rapidly changing sea levels are examined using facies analysis and micromorphology. The section is composed of four lithofacies associations (LAs). These are, from the base, a laminated, fossiliferous and deformed silt (LA1) at least 4.5 m thick that contains lenses of diamicton and discontinuous rafts of sandy gravel. Marine shells form the axis of a fold hinge, part of a lightly tectonised channel fill within the raft. LA1 is overlain by a sandy diamict (LA2) up to 14 m thick containing mainly local clasts with some of northern provenance. Within LA2 are wide channel structures infilled by laminated clayey silts (LA2b). These form deposits up to 14 m thick and contain small-scale folds, discrete shear zones and ball-and-pillow structures. LA2b forms a lithofacies association with LA2, consisting of a lower subfacies of sheared and deformed silts, overlain by sandy diamicton, capped by a striated boulder pavement. These are interpreted to represent retreat/advance cycles of a marine terminating ice margin. Up to five such cycles are identified. LA2 is widely punctuated by fissures and conduits infilled by loose sands and gravels. These are inferred to be emplaced by subglacial meltwater during the final stages of ice sheet advance. Covering both LA2 and LA2b, LA3 is a unit of glaciofluvial outwash, composed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H23D1219P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H23D1219P"><span><span class="hlt">Large</span> <span class="hlt">sedimentary</span> aquifer systems functioning. Constraints by classical isotopic and chemical tools, and REE in the Eocene sand aquifer, SW France</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petelet-Giraud, E.; Negrel, P. J.; Millot, R.; Guerrot, C.; Brenot, A.; Malcuit, E.</p> <p>2010-12-01</p> <p><span class="hlt">Large</span> <span class="hlt">sedimentary</span> aquifer systems often constitute strategic water resources for drinking water supply, agriculture irrigation and industry, but can also represent an energetic resource for geothermal power. <span class="hlt">Large</span> water abstractions can induce complete modification of the natural functioning of such aquifer systems, e.g. with seepage between aquifer layers that can lead to water quality degradation. These <span class="hlt">large</span> aquifer systems thus require rational water management at the <span class="hlt">sedimentary</span> <span class="hlt">basin</span> scale in order to preserve both water quantity and quality. In addition to hydrogeological modelling mainly dealing with water quantity, chemical and isotopic methods were applied to evidence the spatial variability of water characteristics and to turn this into better understanding of hydrosystems functioning. The <span class="hlt">large</span> Eocene Sand aquifer system of the Adour-Garonne <span class="hlt">sedimentary</span> <span class="hlt">basin</span> was studied through various hydrological, chemical and isotopic tools. This system extends over 116,000 km2 (one-fifth of the French territory, located in the South west part). The aquifer being artesian in the west of the district and confined with piezometric levels around 250-m depth in the east. The ‘Eocene Sands’, composed of sandy Tertiary sediments alternating with carbonate deposits, is a multi-layer system with high permeability and a thickness of several tens of metres to a hundred metres..The Eocene Sand aquifer system comprises at least five aquifers: Paleocene, Eocene infra-molassic sands (IMS), early Eocene, middle Eocene, and late Eocene. According to δ18O and δ2H values and estimated 14C ages, both present-day recharge (mainly located in the north of the area) and old recharge (16-35 ky) can be evidenced. High spatial variability was evidenced within a same aquifer layer, with temporal variability over one hydrological cycle limited to a few points located in the recharge areas. These results and especially the very old waters recharged under colder climate combined with the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080031650','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080031650"><span>Previously Unrecognized <span class="hlt">Large</span> Lunar Impact <span class="hlt">Basins</span> Revealed by Topographic Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frey, Herbert V.</p> <p>2008-01-01</p> <p>The discovery of a <span class="hlt">large</span> population of apparently buried impact craters on Mars, revealed as Quasi- Circular Depressions (QCDs) in Mars Orbiting Laser Altimeter (MOLA) data [1,2,3] and as Circular Thin Areas (CTAs) [4] in crustal thickness model data [5] leads to the obvious question: are there unrecognized impact features on the Moon and other bodies in the solar system? Early analysis of Clementine topography revealed several <span class="hlt">large</span> impact <span class="hlt">basins</span> not previously known [6,7], so the answer certainly is "Yes." How <span class="hlt">large</span> a population of previously undetected impact <span class="hlt">basins</span>, their size frequency distribution, and how much these added craters and <span class="hlt">basins</span> will change ideas about the early cratering history and Late Heavy Bombardment on the Moon remains to be determined. Lunar Orbiter Laser Altimeter (LOLA) data [8] will be able to address these issues. As a prelude, we searched the state-of-the-art global topographic grid for the Moon, the Unified Lunar Control Net (ULCN) [9] for evidence of <span class="hlt">large</span> impact features not previously recognized by photogeologic mapping, as summarized by Wilhelms [lo].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMGP21C0788H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMGP21C0788H"><span>Magnetic Anomalies Antipodal to <span class="hlt">Large</span> Impact <span class="hlt">Basins</span> on the Moon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hemant, K.; Purucker, M. E.</p> <p>2008-12-01</p> <p>The high resolution lunar-wide magnetic anomaly map derived from Lunar Prospector (LP) vector magnetometer data has revealed weak anomalies over the nearside <span class="hlt">large</span> impact <span class="hlt">basins</span> flooded by mare basalts. Strong anomaly features are observed over most of the Nectarian and Pre-Nectarian aged lunar highlands. In particular, regions antipodal to some of the largest <span class="hlt">basin</span>-forming impact craters show strong magnetic anomaly concentrations. Of the 43 <span class="hlt">basins</span> investigated here, antipodal regions of 11 <span class="hlt">basins</span> show these anomalous features with strengths in excess of 5-25 nT at LP's mapping altitude (30 km). These distinct anomalous concentrations were previously known to occur only at the antipodes of Imbrium, Orientale, Serenitatis and Crisium <span class="hlt">basins</span>. The mean magnetic anomaly strength within each antipodal region when plotted against increasing age of the antipodes shows two age groupings with similar magnetic behavior. The first age grouping - (Imbrium, Orientale, Serenitatis and Crisium) is of Imbrium to Late Nectarian in age. This grouping is correlative with the peak magnetic field enhancement between 3.6 and 3.9 Gyr, inferred from paleomagnetic data from the returned Apollo samples. The second age grouping ( Lorentz, Coulomb-Sarton, Tranquillitatis, Cognitum and Insularum) is of Mid to Early Pre-Nectarian age. This grouping has not been correlated to any known global magnetic field enhancement event, and needs further investigation to ascertain the origin of the anomalies. The present work supports the antipodal hypothesis as one of the possible mechanisms to explain the observed anomalies at the antipode of the impact <span class="hlt">basin</span>. The absence of appreciable anomalies at the 32 other antipodes, however, indicates the importance of other processes, and superposition effects, that have operated on the Moon during its history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.H72C0870M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.H72C0870M"><span>Comparing Groundwater Contamination Vulnerability in <span class="hlt">Large</span>, Urbanized <span class="hlt">Basins</span> of California</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moran, J. E.; Hudson, G. B.; Leif, R.; Eaton, G. F.</p> <p>2002-12-01</p> <p>We have sampled over 700 public drinking water wells as part of a study to assess relative contamination susceptibility of the major groundwater <span class="hlt">basins</span> in California. The parameters used to rank wells according to vulnerability are groundwater age dates (using the tritium-3helium method), stable isotopes of the water molecule (for water source determination), and occurrence of low level Volatile Organic Compounds (VOCs). Long-screened production wells supply clean, high quality samples, and sample the resource that is being used. However, the groundwater age distribution from production wells may be quite broad, and comparisons to the predicted initial tritium value for the measured mean age, along with analysis of radiogenic 4Helium are used to de-convolute the mixed age. Results from the Los Angeles and Orange County <span class="hlt">Basins</span>, and Santa Clara Valley, will be presented. A <span class="hlt">large</span> volume of both imported and locally captured water is artificially recharged in these intensively managed <span class="hlt">basins</span>. An effective confining unit in the Santa Clara Valley <span class="hlt">basin</span> prevents widespread vertical transport of contaminants down to drinking water wells. In the southern California <span class="hlt">basins</span>, groundwater age and the frequency of occurrence of low-level VOCs are spatially correlated, with more recently recharged water likely to have VOC detections. 'Pre-modern' water is nearly always free of VOCs, except when a suspected 'short circuit', (e.g., loss of integrity in well casing) allows near surface contamination to reach 'old' water. Methyl-tertiary-Butyl Ether (MTBE) can be a useful time marker in groundwater <span class="hlt">basins</span>, with water recharged after the 1980's showing traces of MTBE. Water resource managers can use these vulnerability assessments to focus monitoring efforts, site new wells, plan land use, and evaluate remediation activities. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SedG..359....1C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SedG..359....1C"><span>The transgressive-regressive cycle of the Romualdo Formation (Araripe <span class="hlt">Basin</span>): <span class="hlt">Sedimentary</span> archive of the Early Cretaceous marine ingression in the interior of Northeast Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Custódio, Michele Andriolli; Quaglio, Fernanda; Warren, Lucas Veríssimo; Simões, Marcello Guimarães; Fürsich, Franz Theodor; Perinotto, José Alexandre J.; Assine, Mario Luis</p> <p>2017-08-01</p> <p>Geologic events related to the opening of the South Atlantic Ocean deeply influenced the <span class="hlt">sedimentary</span> record of the Araripe <span class="hlt">Basin</span>. As consequence, upper stratigraphic units of the <span class="hlt">basin</span> record a marine ingression in northeastern Brazil during the late Aptian. The timing and stratigraphic architecture of these units are crucial to understand the paleogeography of Gondwana and how the proto-Atlantic Ocean reached interior NE Brazil during the early Cretaceous. This marine ingression is recorded in the Araripe <span class="hlt">Basin</span> as the Romualdo Formation, characterized by a transgressive-regressive cycle bounded by two regional unconformities. In the eastern part of the <span class="hlt">basin</span>, the Romualdo depositional sequence comprises coastal alluvial and tide-dominated deposits followed by marine transgressive facies characterized by two fossil-rich intervals: a lower interval of black shales with fossil-rich carbonate concretions (Konservat-Lagerstätten) and an upper level with mollusk-dominated shell beds and shelly limestones. Following the marine ingression, an incomplete regressive succession of marginal-marine facies records the return of continental environments to the <span class="hlt">basin</span>. The stratigraphic framework based on the correlation of several sections defines a transgressive-regressive cycle with depositional dip towards southeast, decreasing in thickness towards northwest, and with source areas located at the northern side of the <span class="hlt">basin</span>. The facies-cycle wedge-geometry, together with paleocurrent data, indicates a coastal onlap towards NNW. Therefore, contrary to several paleogeographic scenarios previously proposed, the marine ingression would have reached the western parts of the Araripe <span class="hlt">Basin</span> from the SSE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9314M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9314M"><span>Cosmogenic Nuclides 10Be-21Ne Burial Dating of Middle Miocene <span class="hlt">Sedimentary</span> Formation of the Hongliu Valley in Southern Ningxia <span class="hlt">Basin</span>: A Case of Isotopic Geochronology Study for the Cenozoic <span class="hlt">Sedimentary</span> Strata</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Yan; Zhang, Huiping; Wang, Weitao; Pang, Jianzhang; Zheng, Dewen</p> <p>2016-04-01</p> <p>Chronology studies for the Cenozoic <span class="hlt">sedimentary</span> strata based on the magnetostratigraphy cannot afford the unique chronological sequences in the absence of absolute ages from biostratigraphy or volcanic ash chronology. In situ-produced cosmogenic nuclides provide a powerful tool for the sediment dating based on the time-dependent concentration ratio of two nuclides, which are produced in the same mineral but with different half-lives. Thereinto,10Be-26Al is the most widely used nuclide pairs, of which the available dating range spans the Plio-Pleistocene. But the coupling of 10Be with the stable nuclide 21Ne would significantly improve the burial dating range up to the middle Miocene, which is promising in revolutionizing the chronology study for the Late Cenozoic terrestrial <span class="hlt">sedimentary</span> sequences. We have applied 10Be-21Ne pair for dating the middle Miocene sediments of the Hongliu Valley in southern Ningxia <span class="hlt">basin</span>. Two major features of the sediments are involved in our study: (1) sediments originated from the steady erosion of the source area, and (2) the burial depth of our sample after deposition is time dependent due to the gradual accumulation of sediments into <span class="hlt">basin</span>. The post-burial nuclide production is estimated to be less than 3%, including the contribution by muon interactions, of the total nuclide concentrations measured in our sample. Our 10Be-21Ne analysis demonstrates the age of the burial sample is 12.4(+0.6/-0.4) Ma, and the erosion rate at the source area is 0.26±0.01 cm ka-1. The sample's burial age is consistent with the age constraint set by the Hongliugou Formation (16.7-5.4 Ma) which we collected the sample in. Vertebrate fossils of Platybelodon tongxinensis with an age between 12 and 15 Ma exhumated along with our sample further verifies the reliability of our dating results for the middle Miocene sediments.This study has shown the improved age range of cosmogenic-nuclide burial dating method by incorporating the stable nuclide 21Ne, and has</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.4788C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4788C"><span>Supercritical bedforms and <span class="hlt">sedimentary</span> structures from field and core studies, Middle Eocene deep-marine base-of-slope environment, Ainsa <span class="hlt">Basin</span>, Spanish Pyrenees</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cornard, Pauline; Pickering, Kevin</p> <p>2017-04-01</p> <p>In recent years, many researchers have focussed on supercritical- and subcritical-flow deposits using flume-tank experiments (e.g., Cartigny el al., 2011; Postma et al., 2014; Postma and Cartigny, 2014), or from direct observations on presently active deep-water systems (e.g., Hughes et al., 2012). Using outcrop and core examples from a base-of-slope environment in the Middle Eocene Ainsa <span class="hlt">Basin</span>, Spanish Pyrenees, and with published experimental work, a range of deposits are interpreted as upper-flow regime <span class="hlt">sedimentary</span> structures. This contribution focusses on the interpretation of several supercritical bedforms (antidunes and chutes-and-pools) observed on the field and upper-flow regime <span class="hlt">sedimentary</span> structures recognized in cores. The spatial distribution of supercritical-flow deposits obtained from an analysis of field outcrops and core <span class="hlt">sedimentary</span> logs are evaluated in relation to the depositional environment (channel axis, off-axis, margin and interfan). The frequency distributions of the bed thicknesses are also analysed in relation to supercritical versus subcritical bed-thickness distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.432..187P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.432..187P"><span><span class="hlt">Large</span> Carbonate Associated Sulfate isotopic variability between brachiopods, micrite, and other <span class="hlt">sedimentary</span> components in Late Ordovician strata</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Present, Theodore M.; Paris, Guillaume; Burke, Andrea; Fischer, Woodward W.; Adkins, Jess F.</p> <p>2015-12-01</p> <p>Carbonate Associated Sulfate (CAS) is trace sulfate incorporated into carbonate minerals during their precipitation. Its sulfur isotopic composition is often assumed to track that of seawater sulfate and inform global carbon and oxygen budgets through Earth's history. However, many CAS sulfur isotope records based on bulk-rock samples are noisy. To determine the source of bulk-rock CAS variability, we extracted CAS from different internal <span class="hlt">sedimentary</span> components micro-drilled from well-preserved Late Ordovician and early Silurian-age limestones from Anticosti Island, Quebec, Canada. Mixtures of these components, whose sulfur isotopic compositions vary by nearly 25‰, can explain the bulk-rock CAS range. <span class="hlt">Large</span> isotopic variability of <span class="hlt">sedimentary</span> micrite CAS (34S-depleted from seawater by up to 15‰) is consistent with pore fluid sulfide oxidation during early diagenesis. Specimens recrystallized during burial diagenesis have CAS 34S-enriched by up to 9‰ from Hirnantian seawater, consistent with microbial sulfate reduction in a confined aquifer. In contrast to the other variable components, brachiopods with well-preserved secondary-layer fibrous calcite-a phase independently known to be the best-preserved <span class="hlt">sedimentary</span> component in these strata-have a more homogeneous isotopic composition. These specimens indicate that seawater sulfate remained close to about 25‰ (V-CDT) through Hirnantian (end-Ordovician) events, including glaciation, mass extinction, carbon isotope excursion, and pyrite-sulfur isotope excursion. The textural relationships between our samples and their CAS isotope ratios highlight the role of diagenetic biogeochemical processes in setting the isotopic composition of CAS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAfES.131..272A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAfES.131..272A"><span>Estimation of groundwater recharge in <span class="hlt">sedimentary</span> rock aquifer systems in the Oti <span class="hlt">basin</span> of Gushiegu District, Northern Ghana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Afrifa, George Yamoah; Sakyi, Patrick Asamoah; Chegbeleh, Larry Pax</p> <p>2017-07-01</p> <p>Sustainable development and the management of groundwater resources for optimal socio-economic development constitutes one of the most effective strategies for mitigating the effects of climate change in rural areas where poverty is a critical cause of environmental damage. This research assessed groundwater recharge and its spatial and temporal variations in Gushiegu District in the Northern Region of Ghana, where groundwater is the main source of water supply for most uses. Isotopic data of precipitation and groundwater were used to infer the origin of groundwater and the possible relationship between groundwater and surface water in the partially metamorphosed <span class="hlt">sedimentary</span> aquifer system in the study area. Though the data do not significantly establish strong relation between groundwater and surface water, the study suggests that groundwater in the area is of meteoric origin. However, the data also indicate significant enrichment of the heavy isotopes (18O and 2H) in groundwater relative to rainwater in the area. The Chloride Mass Balance (CMB) and Water Table Fluctuations (WTF) techniques were used to quantitatively estimate the groundwater recharge in the area. The results suggest groundwater recharge in a range of 13.9 mm/y - 218 mm/y, with an average of 89 mm/yr, representing about 1.4%-21.8% (average 8.9%) of the annual precipitation in the area. There is no clearly defined trend in the temporal variations of groundwater recharge in the area, but the spatial variations are discussed in relation to the underlying lithologies. The results suggest that the fraction of precipitation that reaches the saturated zone as groundwater recharge is <span class="hlt">largely</span> controlled by the vertical hydraulic conductivities of the material of the unsaturated zone. The vertical hydraulic conductivity coupled with humidity variations in the area modulates the vertical infiltration and percolation of precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6532908','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6532908"><span>San Juan <span class="hlt">Basin</span> contains <span class="hlt">large</span> reserves of nonassociated gas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rice, D.D.; Threlkeld, C.N.</p> <p>1983-03-07</p> <p>Approximately 23 trillion CF of nonassociated gas occurs in the underpressured, low-permeability reservoirs in the essentially structureless low part of the central San Juan <span class="hlt">basin</span> in northwestern New Mexico and southwestern Colorado. Characteristics and distribution of natural gas and associated hydrocarbons (oil and condensate) for all producing units indicate an increased level of maturation to the northeast: (1) Pennsylvania production is limited mostly to the Four Corners platform, where oil production changes in a northeasterly direction to isotopically heavy dry gas with H/sub 2/S and CO/sub 2/, (2) hydrocarbon production from the Dakota sandstone displays a northeast change from oil to wet gas and condensate to dry gas, (3) the Tocito sandstone Lentil of Mancos shale is a major producer of oil and associated gas in the <span class="hlt">basin</span>, (4) the Mesaverde contains <span class="hlt">large</span> quantities of nonassociated gas generated mainly from nonmarine source rocks, and (5) Pictured Cliffs gases (probably derived from associated coalbeds) are isotopically heavier and chemically drier than gases from the underlying Mesaverde group and produced very little condensate. Significant reserves of nonassociated gas remain in the San Juan <span class="hlt">basin</span> - the primary targets for future exploration will be the coalbeds in the Fruitland formation, channel sandstones and coalbeds in the Menefee formation, and low-permeability sandstones in all units at the north end of the <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGP41A0985C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGP41A0985C"><span>Detecting Light Hydrocarbon Microseepages and related Intra-<span class="hlt">sedimentary</span> Structures at the São Francisco <span class="hlt">Basin</span>, Brazil, using Airborne Geophysical Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curto, J. B.; Pires, A. C.; Silva, A.; Crosta, A. P.</p> <p>2011-12-01</p> <p>The use of indirect techniques for the detection of light hydrocarbons occurrences on the surface, named as microseepages, has been used to augment hydrocarbon exploration. Surveys developed for this type of application are normally targeted at mapping the effects that microseepages cause on the environment. In Brazil, most available airborne geophysical surveys were not appropriately designed for this type of application and, thus far they have been mostly used to define the main <span class="hlt">basin</span> structural features. Existing microseepages are known in Remanso do Fogo area (Minas Gerais State, Brazil), located in São Francisco <span class="hlt">Basin</span>, where the Quaternary <span class="hlt">sedimentary</span> cover made the identification of new occurrences and associated controlling structures quite difficult. This study investigates the spatial distribution of hydrocarbon related structures in shallower to intra-<span class="hlt">sedimentary</span> depths in the Remanso do Fogo area, using airborne magnetic and gamma-ray spectrometry data. These data were managed by the ANP (Brazilian Petroleum National Agency) and conducted by Lasa Engineering & Surveys in 2006. In the study area, data were acquired along north-south flight lines spaced 500 m apart and along orthogonal tie lines flown 4 Km apart at a terrain clearance of 100 m. The geophysical data were processed using techniques developed to suppress the influence of regional geological signatures. For the magnetic data, this study focuses on the enhancement of intra-<span class="hlt">sedimentary</span> structures and possible near surface accumulations of diagenetic magnetic minerals, provided by hydrocarbon related chemical reactions. The amplitude of the analytic signal, calculated with second order derivatives, combined with the total horizontal gradient of the subtraction between the 1200 and 400 meter upward continuations, illuminated the NW and EW magnetic lineaments, which are partially related to the microseepages and the drainage of the area. The distinction of near-surface and deeper signatures also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987GML.....7...59D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987GML.....7...59D"><span>Anomalously <span class="hlt">large</span> marine <span class="hlt">sedimentary</span> units deposited in a single mass wasting event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doyle, Larry J.</p> <p>1987-06-01</p> <p>This note serves to introduce a group of papers centered around the theme of massive submarine gravity deposits, “megaturbidites,” presented in a 1986 AAPG/SEPM Symposium organized by Larry J. Doyle and Robert Bourrouilh. Although “megaturbidite” may be an unfortunate term, massive gravity deposits are significant as marker beds, time lines, and potential hydrocarbon reservoirs, as well as being manifestations of important geological phenomena. The papers which follow begin to explore the inter-relationships among the four principal variables: time, <span class="hlt">basin</span> size and shape, tectonic setting, and sediment accumulation in the provenance areas, which govern the formation of these extraordinary units.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRE..122..701U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRE..122..701U"><span>Protracted volcanism after <span class="hlt">large</span> impacts: Evidence from the Sudbury impact <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ubide, Teresa; Guyett, Paul C.; Kenny, Gavin G.; O'Sullivan, Edel M.; Ames, Doreen E.; Petrus, Joseph A.; Riggs, Nancy; Kamber, Balz S.</p> <p>2017-04-01</p> <p>Morphological studies of <span class="hlt">large</span> impact structures on Mercury, Venus, Mars, and the Moon suggest that volcanism within impact craters may not be confined to the shock melting of target rocks. This possibility prompted reinvestigation of the 1.85 Ga subaqueous Sudbury impact structure, specifically its 1.5 km thick immediate <span class="hlt">basin</span> fill (Onaping Formation). Historically, breccias of this formation were debated in the context of an endogenic versus an impact-fallback origin. New field, petrographic, and in situ geochemical data document an array of igneous features, including vitric shards, bombs, sheet-like intrusions, and peperites, preserved in exquisite textural detail. The geochemistry of vitric materials is affected by alteration, as expected for subaqueous magmatic products. Earlier studies proposed an overall andesitic chemistry for all magmatic products, sourced from the underlying impact melt sheet. The new data, however, suggest progressive involvement of an additional, more magnesian, and volatile-rich magma source with time. We propose a new working model in which only the lower part of the Onaping Formation was derived by explosive "melt-fuel-coolant interaction" when seawater flooded onto the impact melt sheet in the <span class="hlt">basin</span> floor. By contrast, we suggest that the upper 1000 m were deposited during protracted submarine volcanism and <span class="hlt">sedimentary</span> reworking. Magma was initially sourced from the impact melt sheet and up stratigraphy, from reservoirs at greater depth. It follows that volcanic deposits in <span class="hlt">large</span> impact <span class="hlt">basins</span> may be related to magmatism caused by the impact but not directly associated with the impact-generated melt sheet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1818535T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1818535T"><span>Quantitative characterisation of <span class="hlt">sedimentary</span> grains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tunwal, Mohit; Mulchrone, Kieran F.; Meere, Patrick A.</p> <p>2016-04-01</p> <p>Analysis of <span class="hlt">sedimentary</span> texture helps in determining the formation, transportation and deposition processes of <span class="hlt">sedimentary</span> rocks. Grain size analysis is traditionally quantitative, whereas grain shape analysis is <span class="hlt">largely</span> qualitative. A semi-automated approach to quantitatively analyse shape and size of sand sized <span class="hlt">sedimentary</span> grains is presented. Grain boundaries are manually traced from thin section microphotographs in the case of lithified samples and are automatically identified in the case of loose sediments. Shape and size paramters can then be estimated using a software package written on the Mathematica platform. While automated methodology already exists for loose sediment analysis, the available techniques for the case of lithified samples are limited to cases of high definition thin section microphotographs showing clear contrast between framework grains and matrix. Along with the size of grain, shape parameters such as roundness, angularity, circularity, irregularity and fractal dimension are measured. A new grain shape parameter developed using Fourier descriptors has also been developed. To test this new approach theoretical examples were analysed and produce high quality results supporting the accuracy of the algorithm. Furthermore sandstone samples from known aeolian and fluvial environments from the Dingle <span class="hlt">Basin</span>, County Kerry, Ireland were collected and analysed. Modern loose sediments from glacial till from County Cork, Ireland and aeolian sediments from Rajasthan, India have also been collected and analysed. A graphical summary of the data is presented and allows for quantitative distinction between samples extracted from different <span class="hlt">sedimentary</span> environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAESc.115...97D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAESc.115...97D"><span>Spreading dynamics and <span class="hlt">sedimentary</span> process of the Southwest Sub-<span class="hlt">basin</span>, South China Sea: Constraints from multi-channel seismic data and IODP Expedition 349</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Weiwei; Li, Jiabiao; Clift, Peter D.</p> <p>2016-01-01</p> <p>Neotectonic and <span class="hlt">sedimentary</span> processes in the South China Sea abyssal <span class="hlt">basin</span> are still debated because of the lack of drilling evidence to test competing models. In this study, we interpreted four multi-channel seismic profiles across the Southwest Sub-<span class="hlt">basin</span> (SWSB) and achieved stratigraphic correlation with new drilling data from Integrated Ocean Discovery Program (IODP) Expedition 349. Neogene sediments are divided into four stratigraphic units, each with distinctive seismic character. Sedimentation rate and lithology variations suggest climate-controlled sedimentation. In the late Miocene winter monsoon strength and increased aridity in the limited accumulation rates in the SWSB. Since the Pliocene summer monsoons and a variable glacial-interglacial climate since have enhanced accumulation rates. Terrigeneous sediments in the SWSB are most likely derived from the southwest. Three basement domains are classified with different <span class="hlt">sedimentary</span> architectures and basement structures, including hyper-stretched crust, exhumed subcontinental mantle, and steady state oceanic crust. The SWSB has an asymmetric geometry and experienced detachment faulting in the final stage of continental rifting and exhumation of continental mantle lithosphere. Mantle lithospheric breakup post-dates crustal separation, delaying the establishment of oceanic spreading and steady state crust production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1740D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1740D"><span>Spreading Dynamics and <span class="hlt">Sedimentary</span> Process of the Southwest Sub-<span class="hlt">basin</span>, South China Sea: Constraints from multi-channel seismic data and IODP Expedition 349</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Weiwei; Li, Jiabiao; Clift, Peter</p> <p>2016-04-01</p> <p>Neotectonic and <span class="hlt">sedimentary</span> processes in the South China Sea abyssal <span class="hlt">basin</span> are still debated because of the lack of drilling evidence to test competing models. In this study, we interpreted four multi-channel seismic profiles across the Southwest Sub-<span class="hlt">basin</span> (SWSB) and achieved stratigraphic correlation with new drilling data from Integrated Ocean Discovery Program (IODP) Expedition 349. Neogene sediments are divided into four stratigraphic units, each with distinctive seismic character. Sedimentation rate and lithology variations suggest climate-controlled sedimentation. In the late Miocene winter monsoon strength and increased aridity in the limited accumulation rates in the SWSB. Since the Pliocene summer monsoons and a variable glacial-interglacial climate since have enhanced accumulation rates. Terrigeneous sediments in the SWSB are most likely derived from the southwest. Three basement domains are classified with different <span class="hlt">sedimentary</span> architectures and basement structures, including hyper-stretched crust, exhumed subcontinental mantle, and steady state oceanic crust. The SWSB has an asymmetric geometry and experienced detachment faulting in the final stage of continental rifting and exhumation of continental mantle lithosphere. Mantle lithospheric breakup post-dates crustal separation, delaying the establishment of oceanic spreading and steady state crust production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20062587','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20062587"><span>Structure of the lithosphere and Mesozoic <span class="hlt">sedimentary</span> <span class="hlt">basins</span> in western Liaoning, northern Liaoning, and Songliao, northeast China</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xu, M.; Middleton, M.F.; Xue, L.F.; Wang, D.P.</p> <p>2000-03-01</p> <p>The western Liaoning, northern Liaoning, and Songliao areas represent three different tectonic units with different lithosphere thermal-mechanical properties in terms of composition, thickness of the thermal lithosphere, effective elastic thickness, depth of the detachment surface, and strength of the lithosphere. Western Liaoning is characterized by a thick lithosphere with high rigidity and str