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Sample records for hypothetical sedimentary rock

  1. Polygon/Cracked Sedimentary Rock

    Science.gov (United States)

    2004-01-01

    4 December 2004 Exposures of sedimentary rock are quite common on the surface of Mars. Less common, but found in many craters in the regions north and northwest of the giant basin, Hellas, are sedimentary rocks with distinct polygonal cracks in them. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example from the floor of an unnamed crater near 21.0oS, 311.9oW. Such cracks might have formed by desiccation as an ancient lake dried up, or they might be related to ground ice freeze/thaw cycles or some other stresses placed on the original sediment or the rock after it became lithified. The 300 meter scale bar is about 328 yards long. The scene is illuminated by sunlight from the upper left.

  2. Copper Deposits in Sedimentary and Volcanogenic Rocks

    Science.gov (United States)

    Tourtelot, Elizabeth B.; Vine, James David

    1976-01-01

    Copper deposits occur in sedimentary and volcanogenic rocks within a wide variety of geologic environments where there may be little or no evidence of hydrothermal alteration. Some deposits may be hypogene and have a deep-seated source for the ore fluids, but because of rapid cooling and dilution during syngenetic deposition on the ocean floor, the resulting deposits are not associated with hydrothermal alteration. Many of these deposits are formed at or near major tectonic features on the Earth's crust, including plate boundaries, rift valleys, and island arcs. The resulting ore bodies may be stratabound and either massive or disseminated. Other deposits form in rocks deposited in shallow-marine, deltaic, and nonmarine environments by the movement and reaction of interstratal brines whose metal content is derived from buried sedimentary and volcanic rocks. Some of the world's largest copper deposits were probably formed in this manner. This process we regard as diagenetic, but some would regard it as syngenetic, if the ore metals are derived from disseminated metal in the host-rock sequence, and others would regard the process as epigenetic, if there is demonstrable evidence of ore cutting across bedding. Because the oxidation associated with diagenetic red beds releases copper to ground-water solutions, red rocks and copper deposits are commonly associated. However, the ultimate size, shape, and mineral zoning of a deposit result from local conditions at the site of deposition - a logjam in fluvial channel sandstone may result in an irregular tabular body of limited size; a petroleum-water interface in an oil pool may result in a copper deposit limited by the size and shape of the petroleum reservoir; a persistent thin bed of black shale may result in a copper deposit the size and shape of that single bed. The process of supergene enrichment has been largely overlooked in descriptions of copper deposits in sedimentary rocks. However, supergene processes may be

  3. Dynamic Deformation Characteristics of Sedimentary Soft Rock

    Science.gov (United States)

    Fukumoto, Shun'ichi; Yoshida, Nozomu; Sahara, Mamoru

    Soil under the engineering seismic base layer is treated as elastic material in the engineering practice, however, evidence that its nonlinear behavior affects surface response begins to appear. Test data on dynamic deformation characteristics and tri-axial compression test on sedimentary soft rock are collected and compiled to consider its nonlinearity. In addition, nonlinear characteristics of soft rock and note on practical use are described. Static tri-axial compression test of the sample taken by means of diamond core drill is first carried out by using a LDT (Local deformation transducer), and shear modulus is found to keep nearly constant up to strain of about 10-3 for the undisturbed sample, whereas that decreases significantly even at strain of 10-5. Secondly, dynamic deformation test data on Pleistocene and Tertiary soft rock with SPT-N value greater than 30 or shear wave velocity greater than 300 m/s is collected and compiled. It is found that there exist data that shows similar behavior of static test described in the preceding. These samples is supposed be undisturbed, which means there exists many disturbed samples even if they are retrieved by, so called, undisturbed sampling method. Shear modulus at shear strain of 10-3, which is used as index of nonlinearity, is independent from effective confining stress, but it has positive correlation with plastic index. Finally, dynamic deformation characteristics of undisturbed samples are shown to be modeled by Ramberg-Osgood model well.

  4. Excess europium content in Precambrian sedimentary rocks and continental evolution

    Science.gov (United States)

    Jakes, P.; Taylor, S. R.

    1974-01-01

    It is proposed that the europium excess in Precambrian sedimentary rocks, relative to those of younger age, is derived from volcanic rocks of ancient island arcs, which were the source materials for the sediments. Precambrian sedimentary rocks and present-day volcanic rocks of island arcs have similar REE patterns, total REE abundances, and excess Eu, relative to the North American shale composite. The present upper crustal REE pattern, as exemplified by that of sediments, is depleted in Eu, relative to chondrites. This depletion is considered to be a consequence of development of a granodioritic upper crust by partial melting in the lower crust, which selectively retains europium.

  5. Favorability for uranium in tertiary sedimentary rocks, southwestern Montana

    Energy Technology Data Exchange (ETDEWEB)

    Wopat, M A; Curry, W E; Robins, J W; Marjaniemi, D K

    1977-10-01

    Tertiary sedimentary rocks in the basins of southwestern Montana were studied to determine their favorability for potential uranium resources. Uranium in the Tertiary sedimentary rocks was probably derived from the Boulder batholith and from silicic volcanic material. The batholith contains numerous uranium occurrences and is the most favorable plutonic source for uranium in the study area. Subjective favorability categories of good, moderate, and poor, based on the number and type of favorable criteria present, were used to classify the rock sequences studied. Rocks judged to have good favorability for uranium deposits are (1) Eocene and Oligocene strata and undifferentiated Tertiary rocks in the western Three Forks basin and (2) Oligocene rocks in the Helena basin. Rocks having moderate favorability consist of (1) Eocene and Oligocene strata in the Jefferson River, Beaverhead River, and lower Ruby River basins, (2) Oligocene rocks in the Townsend and Clarkston basins, (3) Miocene and Pliocene rocks in the Upper Ruby River basin, and (4) all Tertiary sedimentary formations in the eastern Three Forks basin, and in the Grasshopper Creek, Horse Prairie, Medicine Lodge Creek, Big Sheep Creek, Deer Lodge, Big Hole River, and Bull Creek basins. The following have poor favorability: (1) the Beaverhead Conglomerate in the Red Rock and Centennial basins, (2) Eocene and Oligocene rocks in the Upper Ruby River basin, (3) Miocene and Pliocene rocks in the Townsend, Clarkston, Smith River, and Divide Creek basins, (4) Miocene through Pleistocene rocks in the Jefferson River, Beaverhead River, and Lower Ruby River basins, and (5) all Tertiary sedimentary rocks in the Boulder River, Sage Creek, Muddy Creek, Madison River, Flint Creek, Gold Creek, and Bitterroot basins.

  6. Peculiarities of geodeformation measurements of near surface sedimentary rocks

    Directory of Open Access Journals (Sweden)

    Larionov Igor

    2016-01-01

    Full Text Available The results of investigations of the deformation process in the near surface sedimentary rocks are presented. These investigations have been carried out in a seismically active region of Kamchatka peninsula since 2007. The peculiarity of the experiments is the application of a laser strainmeter-interferometer constructed according to the Michelson interferometer scheme.

  7. FEATURES OF GEODEFORMATION CHANGES OF NEAR SURFACE SEDIMENTARY ROCKS

    Directory of Open Access Journals (Sweden)

    I. A. Larionov

    2016-11-01

    Full Text Available The results of investigations of the deformation process in the near surface sedimentary rocks, which has been carried out in a seismically active region of Kamchatka peninsular since 2007,are presented. The peculiarity of the experiments on the registration of geodeformations is the application of a laser deformograph-interferometer constructed according to the Michelson interferometer scheme.

  8. Determination of petrophysical properties of sedimentary rocks by optical methods

    Science.gov (United States)

    Korte, D.; Kaukler, D.; Fanetti, M.; Cabrera, H.; Daubront, E.; Franko, M.

    2017-04-01

    Petrophysical properties of rocks (thermal diffusivity and conductivity, porosity and density) as well as the correlation between them are of great importance for many geoscientific applications. The porosity of the reservoir rocks and their permeability are the most fundamental physical properties with respect to the storage and transmission of fluids, mainly oil characterization. Accurate knowledge of these parameters for any hydrocarbon reservoir is required for efficient development, management, and prediction of future performance of the oilfield. Thus, the porosity and permeability, as well as the chemical composition must be quantified as precisely as possible. This should be done along with the thermal properties, density, conductivity, diffusivity and effusivity that are intimately related with them. For this reason, photothermal Beam Deflection Spectrometry (BDS) technique for determination of materials' thermal properties together with other methods such as Energy Dispersive X-ray Scanning Electron Microscopy (SEM-EDX) for determining the chemical composition and sample structure, as well as optical microscopy to determine the particles size, were applied for characterization of sedimentary rocks. The rocks were obtained from the Andes south flank in the Venezuela's western basin. The validation of BDS applicability for determination of petrophysical properties of three sedimentary rocks of different texture and composition (all from Late Cretaceous associated with the Luna, Capacho and Colón-Mito Juan geological formations) was performed. The rocks' thermal properties were correlated to the microstructures and chemical composition of the examined samples.

  9. Permeability-porosity relationships in sedimentary rocks

    Science.gov (United States)

    Nelson, Philip H.

    1994-01-01

    In many consolidated sandstone and carbonate formations, plots of core data show that the logarithm of permeability (k) is often linearly proportional to porosity (??). The slope, intercept, and degree of scatter of these log(k)-?? trends vary from formation to formation, and these variations are attributed to differences in initial grain size and sorting, diagenetic history, and compaction history. In unconsolidated sands, better sorting systematically increases both permeability and porosity. In sands and sandstones, an increase in gravel and coarse grain size content causes k to increase even while decreasing ??. Diagenetic minerals in the pore space of sandstones, such as cement and some clay types, tend to decrease log(k) proportionately as ?? decreases. Models to predict permeability from porosity and other measurable rock parameters fall into three classes based on either grain, surface area, or pore dimension considerations. (Models that directly incorporate well log measurements but have no particular theoretical underpinnings from a fourth class.) Grain-based models show permeability proportional to the square of grain size times porosity raised to (roughly) the fifth power, with grain sorting as an additional parameter. Surface-area models show permeability proportional to the inverse square of pore surface area times porosity raised to (roughly) the fourth power; measures of surface area include irreducible water saturation and nuclear magnetic resonance. Pore-dimension models show permeability proportional to the square of a pore dimension times porosity raised to a power of (roughly) two and produce curves of constant pore size that transgress the linear data trends on a log(k)-?? plot. The pore dimension is obtained from mercury injection measurements and is interpreted as the pore opening size of some interconnected fraction of the pore system. The linear log(k)-?? data trends cut the curves of constant pore size from the pore-dimension models

  10. Chlorine isotope behavior during prograde metamorphism of sedimentary rocks

    Science.gov (United States)

    Selverstone, Jane; Sharp, Zachary D.

    2015-05-01

    Chlorine stable isotope compositions of two sedimentary sequences and their metamorphic equivalents were measured in order to study fractionation effects during prograde metamorphism and devolatilization. Protoliths (n = 25) were collected from a 50 m section of Triassic fluvial and playa-lake strata and Jurassic (Liassic) marine black shales in a well-characterized quarry. Low greenschist to middle amphibolite facies equivalents (n > 80) were collected from the Glarus Alps, Urseren Zone, and Lucomagno region. Bulk δ37Cl values are constant within individual sedimentary layers, but vary from -2.0 to + 2.4 ‰ in Triassic rocks and from -3.0 to 0‰ in the black shales. Dolomitic and gypsiferous samples have positive δ37Cl values, but marls and shales are isotopically negative. Bulk Cl contents show only small declines during the earliest stages of metamorphism. Metamorphic equivalents of the Triassic and Liassic protoliths record the same overall ranges in δ37Cl as their protoliths. Samples with highly correlated bulk compositions but different metamorphic grade show no statistically significant difference in δ37Cl. These data lead to the following conclusions: (1) Terrestrial and marine sedimentary rocks display large primary heterogeneities in chlorine isotope composition. As a result, an unambiguous "sedimentary signature" does not exist in the chlorine stable isotope system. (2) No isotopic fractionation is discernable during metamorphic devolatilization, even at low temperatures. Alpine-style metamorphism thus has little to no effect on bulk chlorine isotopic compositions, despite significant devolatilization. (3) Cl is largely retained in the rocks during devolatilization, contrary to the normally assumed hydrophilic behavior of chlorine. Continuous release of mixed-volatile C-O-H fluids likely affected Cl partitioning between fluid and minerals and allowed chlorine to remain in the rocks. (4) There is no evidence for fluid communication across (meta)sedimentary

  11. Predicting the transport properties of sedimentary rocks from microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, Erika M. [Univ. of California, Berkeley, CA (United States)

    1995-01-01

    Understanding transport properties of sedimentary rocks, including permeability, relative permeability, and electrical conductivity, is of great importance for petroleum engineering, waste isolation, environmental restoration, and other applications. These transport properties axe controlled to a great extent by the pore structure. How pore geometry, topology, and the physics and chemistry of mineral-fluid and fluid-fluid interactions affect the flow of fluids through consolidated/partially consolidated porous media are investigated analytically and experimentally. Hydraulic and electrical conductivity of sedimentary rocks are predicted from the microscopic geometry of the pore space. Cross-sectional areas and perimeters of individual pores are estimated from two-dimensional scanning electron microscope (SEM) photomicrographs of rock sections. Results, using Berea, Boise, Massilon, and Saint-Gilles sandstones show close agreement between the predicted and measured permeabilities. Good to fair agreement is found in the case of electrical conductivity. In particular, good agreement is found for a poorly cemented rock such as Saint-Gilles sandstone, whereas the agreement is not very good for well-cemented rocks. The possible reasons for this are investigated. The surface conductance contribution of clay minerals to the overall electrical conductivity is assessed. The effect of partial hydrocarbon saturation on overall rock conductivity, and on the Archie saturation exponent, is discussed. The region of validity of the well-known Kozeny-Carman permeability formulae for consolidated porous media and their relationship to the microscopic spatial variations of channel dimensions are established. It is found that the permeabilities predicted by the Kozeny-Carman equations are valid within a factor of three of the observed values methods.

  12. Formation of Ocean Sedimentary Rocks as Active Planets and Life-Like Systems

    Science.gov (United States)

    Miura, Y.

    2017-10-01

    Wet shocked rocks are discarded globally and enriched elements in ocean-sedimentary rocks, which is strong indicator of ocean water of other planets. Ocean-sedimentary rocks are strong indicator of water planets and possible exo-life on planet Mars.

  13. The shapes of cold, high mountains in sedimentary rocks

    Science.gov (United States)

    Cruden, D. M.

    2003-09-01

    Terzaghi (Geotechnique 12 (1962) 251) and Young (Young, A., 1972. Slopes. Oliver and Boyd, Edinburgh, 288 pp.) described the stable forms of slopes in sedimentary rock masses, assuming penetrative discontinuities, which are parallel to bedding and joints which are perpendicular to bedding. The only movements considered were slides along bedding. Experience in the Canadian Rockies indicates that the cohesionless rock masses that exist at or above tree line may also move by toppling, buckling and sliding along joints. These processes also act to limit the inclinations of stable slopes. Rock strength is a factor in the critical height of a slope that buckles. The processes can be represented as fields on a process diagram, a plot of slope inclination against bedding dip, using the basic friction angles of the rocks present. The process diagram also separates five common mountain peak shapes, which form on homoclinal sequences of beds. Castellate and Matterhorn mountains occur in sub-horizontal beds, cuestas develop in gently to moderately dipping beds. Hogbacks formed in moderately to steeply dipping beds have similar slope angles on both cataclinal and anaclinal slopes. Dogtooth mountains occur in steeply dipping sub-vertical beds.

  14. Consumption and diffusion of dissolved oxygen in sedimentary rocks.

    Science.gov (United States)

    Manaka, M; Takeda, M

    2016-10-01

    Fe(II)-bearing minerals (e.g., biotite, chlorite, and pyrite) are a promising reducing agent for the consumption of atmospheric oxygen in repositories for the geological disposal of high-level radioactive waste. To estimate effective diffusion coefficients (D e , in m 2 s -1 ) for dissolved oxygen (DO) and the reaction rates for the oxidation of Fe(II)-bearing minerals in a repository environment, we conducted diffusion-chemical reaction experiments using intact rock samples of Mizunami sedimentary rock. In addition, we conducted batch experiments on the oxidation of crushed sedimentary rock by DO in a closed system. From the results of the diffusion-chemical reaction experiments, we estimated the values of D e for DO to lie within the range 2.69×10 -11 rock is limited to the sites that originally existed with accessible porosity for O 2(aq) . This difference arises because the batch experiments used powdered samples, meaning that new sites which formed during milling were added to the original reaction sites. On the basis of these observations and interpretations, diffusion-chemical reaction experiments make it possible to determine the values of the kinetic parameter and diffusivity for an intact rock sample simultaneously. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Thermal conductivity of sedimentary rocks as function of Biot’s coefficient

    DEFF Research Database (Denmark)

    Orlander, Tobias; Pasquinelli, Lisa; Asmussen, J.J.

    2017-01-01

    A theoretical model for prediction of effective thermal conductivity with application to sedimentary rocks is presented. Effective thermal conductivity of sedimentary rocks can be estimated from empirical relations or theoretically modelled. Empirical relations are limited to the empirical...... conductivity of solids is typically orders of magnitude larger than that of fluids, grain contacts constituting the solid connectivity governs the heat transfer of sedi-mentary rocks and hence should be the basis for modelling effective thermal con-ductivity. By introducing Biot’s coefficient, α, we propose (1...... – α) as a measure of the solid connectivity and show how effective thermal conductivity of water saturated and dry sandstones can be modelled....

  16. Evaluation of Aquifer Characteristics of Voltaian Sedimentary Rocks ...

    African Journals Online (AJOL)

    Ground-water potential of the sedimentary aquifer system could be classified as high to intermediate to yield substantial groundwater resource for domestic and industrial water supply. To secure sub-stantial quantity of water for sustainable water supply in areas underlain by this sedimentary aqui-fer system in Ghana, ...

  17. Classification scheme for sedimentary and igneous rocks in Gale crater, Mars

    Science.gov (United States)

    Mangold, N.; Schmidt, M. E.; Fisk, M. R.; Forni, O.; McLennan, S. M.; Ming, D. W.; Sautter, V.; Sumner, D.; Williams, A. J.; Clegg, S. M.; Cousin, A.; Gasnault, O.; Gellert, R.; Grotzinger, J. P.; Wiens, R. C.

    2017-03-01

    Rocks analyzed by the Curiosity rover in Gale crater include a variety of clastic sedimentary rocks and igneous float rocks transported by fluvial and impact processes. To facilitate the discussion of the range of lithologies, we present in this article a petrological classification framework adapting terrestrial classification schemes to Mars compositions (such as Fe abundances typically higher than for comparable lithologies on Earth), to specific Curiosity observations (such as common alkali-rich rocks), and to the capabilities of the rover instruments. Mineralogy was acquired only locally for a few drilled rocks, and so it does not suffice as a systematic classification tool, in contrast to classical terrestrial rock classification. The core of this classification involves (1) the characterization of rock texture as sedimentary, igneous or undefined according to grain/crystal sizes and shapes using imaging from the ChemCam Remote Micro-Imager (RMI), Mars Hand Lens Imager (MAHLI) and Mastcam instruments, and (2) the assignment of geochemical modifiers based on the abundances of Fe, Si, alkali, and S determined by the Alpha Particle X-ray Spectrometer (APXS) and ChemCam instruments. The aims are to help understand Gale crater geology by highlighting the various categories of rocks analyzed by the rover. Several implications are proposed from the cross-comparisons of rocks of various texture and composition, for instance between in place outcrops and float rocks. All outcrops analyzed by the rover are sedimentary; no igneous outcrops have been observed. However, some igneous rocks are clasts in conglomerates, suggesting that part of them are derived from the crater rim. The compositions of in-place sedimentary rocks contrast significantly with the compositions of igneous float rocks. While some of the differences between sedimentary rocks and igneous floats may be related to physical sorting and diagenesis of the sediments, some of the sedimentary rocks (e

  18. Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale crater, Mars.

    Science.gov (United States)

    McLennan, S M; Anderson, R B; Bell, J F; Bridges, J C; Calef, F; Campbell, J L; Clark, B C; Clegg, S; Conrad, P; Cousin, A; Des Marais, D J; Dromart, G; Dyar, M D; Edgar, L A; Ehlmann, B L; Fabre, C; Forni, O; Gasnault, O; Gellert, R; Gordon, S; Grant, J A; Grotzinger, J P; Gupta, S; Herkenhoff, K E; Hurowitz, J A; King, P L; Le Mouélic, S; Leshin, L A; Léveillé, R; Lewis, K W; Mangold, N; Maurice, S; Ming, D W; Morris, R V; Nachon, M; Newsom, H E; Ollila, A M; Perrett, G M; Rice, M S; Schmidt, M E; Schwenzer, S P; Stack, K; Stolper, E M; Sumner, D Y; Treiman, A H; VanBommel, S; Vaniman, D T; Vasavada, A; Wiens, R C; Yingst, R A

    2014-01-24

    Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron- and halogen-rich components, magnesium-iron-chlorine-rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.

  19. Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

    Energy Technology Data Exchange (ETDEWEB)

    Croff, A.G.; Lomenick, T.F.; Lowrie, R.S.; Stow, S.H.

    2003-11-15

    The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host rocks. Shale was determined to be the most preferred of the five rock types, with sandstone a distant second, the carbonate rocks and anhydrock a more distant third, and chalk a relatively close fourth.

  20. Geoengineering Research for a Deep Underground Science and Engineering Laboratory in Sedimentary Rock

    Science.gov (United States)

    Mauldon, M.

    2004-12-01

    A process to identify world-class research for a Deep Underground Science and Engineering Laboratory (DUSEL) in the USA has been initiated by NSF. While allowing physicists to study, inter alia, dark matter and dark energy, this laboratory will create unprecedented opportunities for biologists to study deep life, geoscientists to study crustal processes and geoengineers to study the behavior of rock, fluids and underground cavities at depth, on time scales of decades. A substantial portion of the nation's future infrastructure is likely to be sited underground because of energy costs, urban crowding and vulnerability of critical surface facilities. Economic and safe development of subsurface space will require an improved ability to engineer the geologic environment. Because of the prevalence of sedimentary rock in the upper continental crust, much of this subterranean infrastructure will be hosted in sedimentary rock. Sedimentary rocks are fundamentally anisotropic due to lithology and bedding, and to discontinuities ranging from microcracks to faults. Fractures, faults and bedding planes create structural defects and hydraulic pathways over a wide range of scales. Through experimentation, observation and monitoring in a sedimentary rock DUSEL, in conjunction with high performance computational models and visualization tools, we will explore the mechanical and hydraulic characteristics of layered rock. DUSEL will permit long-term experiments on 100 m blocks of rock in situ, accessed via peripheral tunnels. Rock volumes will be loaded to failure and monitored for post-peak behavior. The response of large rock bodies to stress relief-driven, time-dependent strain will be monitored over decades. Large block experiments will be aimed at measurement of fluid flow and particle/colloid transport, in situ mining (incl. mining with microbes), remediation technologies, fracture enhancement for resource extraction and large scale long-term rock mass response to induced

  1. The potassic sedimentary rocks in Gale Crater, Mars, as seen by ChemCam Onboard Curiosity

    Science.gov (United States)

    Le Deit, Laetitia; Mangold, Nicolas; Forni, Olivier; Cousin, Agnes; Lasue, Jeremie; Schröder, Susanne; Wiens, Roger C.; Sumner, Dawn Y.; Fabre, Cecile; Stack, Katherine M.; Anderson, Ryan; Blaney, Diana L.; Clegg, Samuel M.; Dromart, Gilles; Fisk, Martin; Gasnault, Olivier; Grotzinger, John P.; Gupta, Sanjeev; Lanza, Nina; Le Mouélic, Stephane; Maurice, Sylvestre; McLennan, Scott M.; Meslin, Pierre-Yves; Nachon, Marion; Newsom, Horton E.; Payre, Valerie; Rapin, William; Rice, Melissa; Sautter, Violaine; Treiman, Alan H.

    2016-01-01

    The Mars Science Laboratory rover Curiosity encountered potassium-rich clastic sedimentary rocks at two sites in Gale Crater, the waypoints Cooperstown and Kimberley. These rocks include several distinct meters thick sedimentary outcrops ranging from fine sandstone to conglomerate, interpreted to record an ancient fluvial or fluvio-deltaic depositional system. From ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) chemical analyses, this suite of sedimentary rocks has an overall mean K2O abundance that is more than 5 times higher than that of the average Martian crust. The combined analysis of ChemCam data with stratigraphic and geographic locations reveals that the mean K2O abundance increases upward through the stratigraphic section. Chemical analyses across each unit can be represented as mixtures of several distinct chemical components, i.e., mineral phases, including K-bearing minerals, mafic silicates, Fe-oxides, and Fe-hydroxide/oxyhydroxides. Possible K-bearing minerals include alkali feldspar (including anorthoclase and sanidine) and K-bearing phyllosilicate such as illite. Mixtures of different source rocks, including a potassium-rich rock located on the rim and walls of Gale Crater, are the likely origin of observed chemical variations within each unit. Physical sorting may have also played a role in the enrichment in K in the Kimberley formation. The occurrence of these potassic sedimentary rocks provides additional evidence for the chemical diversity of the crust exposed at Gale Crater.

  2. Integrated geophysical and geological investigations applied to sedimentary rock mass characterization

    Directory of Open Access Journals (Sweden)

    S. Negri

    2008-06-01

    Full Text Available The Salento Peninsula (south-eastern Italy is characterized by sedimentary rocks. The carbonatic nature of the rocks means they are affected by karst phenomena, forming such features as sinkholes, collapsed dolines and caverns, as a result of chemical leaching of carbonates by percolating water. The instability of these phenomena often produces land subsidence problems. The importance of these events is increasing due to growing urbanization, numerous quarries affecting both the subsoil and the surface, and an important coastline characterized by cliffs. This paper focuses on geological and geophysical methods for the characterization of soft sedimentary rock, and presents the results of a study carried out in an urban area of Salento. Taking the Q system derived by Barton (2002 as the starting point for the rock mass classification, a new approach and a modification of the Barton method are proposed. The new equation proposed for the classification of sedimentary rock mass (Qsrm takes account of the permeability of the rock masses, the geometry of the exposed rock face and their types (for example, quarry face, coastal cliff or cavity, the nature of the lithotypes that constitute the exposed sequence, and their structure and texture. This study revises the correlation between Vp and Q derived by Barton (2002, deriving a new empirical equation correlating P-wave velocities and Qsrm values in soft sedimentary rock. We also present a case history in which stratigraphical surveys, Electrical Resistivity Tomography (ERT, and seismic surveys were applied to in situ investigations of subsidence phenomena in an urban area to estimate rock mass quality. Our work shows that in the analysis of ground safety it is important to establish the rock mass quality of the subsurface structures; geophysical exploration can thus play a key role in the assessment of subsidence risk.

  3. Prediction of thermal conductivity of sedimentary rocks from well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea

    2014-01-01

    The calculation of heat-flow density in boreholes requires reliable values for the change of temperature and rock thermal conductivity with depth. As rock samples for laboratory measurements of thermal conductivity (TC) are usually rare geophysical well logs are used alternatively to determine TC...... combinations of standard geophysical well-logs. In combination with a feasible mixing-model (i.e. geometric mean model) bulk TC is computed along borehole profiles. The underlying approach was proposed by Fuchs & Förster (2014) and rests upon the detailed analysis of the interrelations between major physical...

  4. Potential Cement Phases in Sedimentary Rocks Drilled by Curiosity at Gale Crater, Mars

    Science.gov (United States)

    Rampe, E. B.; Morris, R. V.; Bish, D. L.; Chipera, S. J.; Ming, D. W.; Blake, D. F.; Vaniman, D. T.; Bristow, T. F.; Cavanagh, P.; Farmer, J. D.; hide

    2015-01-01

    The Mars Science Laboratory rover Curiosity has encountered a variety of sedimentary rocks in Gale crater with different grain sizes, diagenetic features, sedimentary structures, and varying degrees of resistance to erosion. Curiosity has drilled three rocks to date and has analyzed the mineralogy, chemical composition, and textures of the samples with the science payload. The drilled rocks are the Sheepbed mudstone at Yellowknife Bay on the plains of Gale crater (John Klein and Cumberland targets), the Dillinger sandstone at the Kimberley on the plains of Gale crater (Windjana target), and a sedimentary unit in the Pahrump Hills in the lowermost rocks at the base of Mt. Sharp (Confidence Hills target). CheMin is the Xray diffractometer on Curiosity, and its data are used to identify and determine the abundance of mineral phases. Secondary phases can tell us about aqueous alteration processes and, thus, can help to elucidate past aqueous environments. Here, we present the secondary mineralogy of the rocks drilled to date as seen by CheMin and discuss past aqueous environments in Gale crater, the potential cementing agents in each rock, and how amorphous materials may play a role in cementing the sediments.

  5. Discrete Fracture Networks Groundwater Modelling at Bedding Control Fractured Sedimentary Rock mass

    Science.gov (United States)

    Pin, Yeh; Yuan-Chieh, Wu

    2017-04-01

    Groundwater flow modelling in fractured rock mass is an important challenging work in predicting the transport of contamination. So far as we know about the numerical analysis method was consider for crystalline rock, which means discontinuous are treated as stochastic distribution in homogeneous rock mass. Based on the understanding of geology in Taiwan in past few decades, we know that the hydraulic conductivities of Quaternary and Tertiary system rock mass are strongly controlled by development of sedimentary structures (bedding plane). The main purpose of this study is to understand how Discrete Fracture Networks (DFN) affects numerical results in terms of hydraulic behavior using different DFN generation methods. Base on surface geology investigation and core drilling work (3 boreholes with a total length of 120m), small scale fracture properties with in Cho-lan formation (muddy sandstone) are defined, including gently dip of bedding and 2 sub-vertical joint sets. Two FracMan/MAFIC numerical modellings are conducted, using ECPM approach (Equivalent Continuum Porous Media); case A considered all fracture were Power law distribution with Poisson fracture center; case B considered all bedding plans penetrate into modelling region, and remove the bedding count to recalculate joint fracture parameters. Modelling results show that Case B gives stronger groundwater pathways than Case A and have impact on flow field. This preliminary modelling result implicates the groundwater flow modelling work in some fractured sedimentary rock mass, might be considerate to rock sedimentary structure development itself, discontinuous maybe not follow the same stochastic DFN parameter.

  6. Highly Shocked Low Density Sedimentary Rocks from the Haughton Impact Structure, Devon Island, Nunavut, Canada

    Science.gov (United States)

    Osinski, G. R.; Spray, J. G.

    2001-01-01

    We present the preliminary results of a detailed investigation of the shock effects in highly shocked, low density sedimentary rocks from the Haughton impact structure. We suggest that some textural features can be explained by carbonate-silicate immiscibility. Additional information is contained in the original extended abstract.

  7. A CONTRIBUTION TO THE RESEARCH ON RARE EARTH ELEMENTS IN SEDIMENTARY ROCKS

    Directory of Open Access Journals (Sweden)

    Josip Crnički

    1989-12-01

    Full Text Available The main features of the geochemistry of rare earth elements (REE, REE mineralogy and the REE i contents and distributions in sedimentary rocks are presented. A new classification of REE minerals as well as a new systematic order of the REE behaviour in sedimentology is introduced and explained.

  8. Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale crater, Mars

    NARCIS (Netherlands)

    McLennan, S.M.; Anderson, R.B.; Bell III, J.F.; Bridges, J.C.; Calef III, F.; Campbell, J.L.; Clark, B.C.; Clegg, S.; Conrad, P.; Cousin, A.; Des Marais, D.J.; Dromart, G.; Dyar, M.D.; Edgar, L.A.; Ehlmann, B.L.; Fabre, C.; Forni, O.; Gasnault, O.; Gellert, R.; Gordon, S.; Grant, J.A.; Grotzinger, J.P.; Gupta, S.; Herkenhoff, K.E.; Hurowitz, J.A.; King, P.L.; Mouélic, S.L.; Leshin, L.A.; Léveillé, R.; Lewis, K.W.; Mangold, N.; Maurice, S.; Ming, D.W.; Morris, R.V.; Nachon, M.; Newsom, H.E.; Ollila, A.M.; Perrett, G.M.; Rice, M.S.; Schmidt, M.E.; Schwenzer, S.P.; Stack, K.; Stolper, E.M.; Sumner, D.Y.; Treiman, A.H.; VanBommel, S.; Vaniman, D.T.; Vasavada, A.; Wiens, R.C.; Yingst, R.A.; ten Kate, Inge Loes|info:eu-repo/dai/nl/292012217

    2014-01-01

    Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold,

  9. Classification Scheme for Diverse Sedimentary and Igneous Rocks Encountered by MSL in Gale Crater

    Science.gov (United States)

    Schmidt, M. E.; Mangold, N.; Fisk, M.; Forni, O.; McLennan, S.; Ming, D. W.; Sumner, D.; Sautter, V.; Williams, A. J.; Gellert, R.

    2015-01-01

    The Curiosity Rover landed in a lithologically and geochemically diverse region of Mars. We present a recommended rock classification framework based on terrestrial schemes, and adapted for the imaging and analytical capabilities of MSL as well as for rock types distinctive to Mars (e.g., high Fe sediments). After interpreting rock origin from textures, i.e., sedimentary (clastic, bedded), igneous (porphyritic, glassy), or unknown, the overall classification procedure (Fig 1) involves: (1) the characterization of rock type according to grain size and texture; (2) the assignment of geochemical modifiers according to Figs 3 and 4; and if applicable, in depth study of (3) mineralogy and (4) geologic/stratigraphic context. Sedimentary rock types are assigned by measuring grains in the best available resolution image (Table 1) and classifying according to the coarsest resolvable grains as conglomerate/breccia, (coarse, medium, or fine) sandstone, silt-stone, or mudstone. If grains are not resolvable in MAHLI images, grains in the rock are assumed to be silt sized or smaller than surface dust particles. Rocks with low color contrast contrast between grains (e.g., Dismal Lakes, sol 304) are classified according to minimum size of apparent grains from surface roughness or shadows outlining apparent grains. Igneous rocks are described as intrusive or extrusive depending on crystal size and fabric. Igneous textures may be described as granular, porphyritic, phaneritic, aphyric, or glassy depending on crystal size. Further descriptors may include terms such as vesicular or cumulate textures.

  10. Pre-lithification tectonic foliation development in a clastic sedimentary rock sequence from SW Ireland

    Science.gov (United States)

    Meere, Patrick; Mulchrone, Kieran; McCarthy, David

    2017-04-01

    The current orthodoxy regarding the development of regionally developed penetrative tectonic cleavage fabrics in sedimentary rocks is that it postdates lithification of those rocks. It is well established that fabric development under these circumstances is achieved by a combination of grain rigid body rotation, crystal-plastic deformation and pressure solution. The latter is believed to be the primary mechanism responsible for the domainal nature of cleavage development commonly observed in low grade metamorphic rocks. While there have been advocates for the development of tectonic cleavages before host rock lithification these are currently viewed as essentially local aberrations without regional significance. In this study we combine new field observations with strain analysis, element mapping and modelling to characterise Acadian (>50%) crustal shortening in a Devonian clastic sedimentary sequence from the Dingle Peninsula of south west Ireland. Fabrics in these rocks reflect significant levels of tectonic shortening are a product of grain translation, rigid body rotation and repacking of intra- and extra-formational clasts during deformation of an unconsolidated clastic sedimentary sequence. There is an absence of the expected domainal cleavage structure and intra-clast deformation expected with conventional cleavage formation. This study requires geologists to consider the possibility such a mechanism contributing to tectonic strain in a wide range of geological settings and to look again at field evidence that indicates early sediment mobility during deformation.

  11. Sedimentary basin geochemistry and fluid/rock interactions workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  12. Effect of Water Saturation on the Fracture and Mechanical Properties of Sedimentary Rocks

    Science.gov (United States)

    Guha Roy, Debanjan; Singh, T. N.; Kodikara, J.; Das, Ratan

    2017-10-01

    Fracture and mechanical properties of the water saturated sedimentary rocks have been experimentally investigated in the present paper. Three types of sandstones and one type of shale were saturated in water for different periods of time. They were then tested for their index geomechanical properties such as Brazilian tensile strength (BTS), Young's modulus (YM), P-wave velocity and all pure and mixed-mode fracture toughness (FT). FT was measured using semicircular bend specimens in a three-point bend set-up. All the geomechanical and fracture properties of the saturated rocks were compared together to investigate their interrelations. Further, statistical methods were employed to measure the statistical significance of such relationships. Next, three types of fracture criteria were compared with the present experimental results. Results show that degree of saturation has significant effect on both the strength and fracture properties of sedimentary rock. A general decrease in the mechanical and fracture toughness was noticed with increasing saturation levels. But, t-test confirmed that FT, BTS, P-wave velocity and YM are strongly dependent on each other and linear relationships exist across all the saturation values. Calculation of the `degradation degree' (DD) appeared to be a difficult task for all types of sedimentary rocks. While in sandstone, both the BTS and mode-I FT overestimated the DD calculated by YM method, in shale BTS was found to give a closure value.

  13. Hydro-mechanical modelling of a shaft seal in crystalline and sedimentary host rock media using COMSOL

    Energy Technology Data Exchange (ETDEWEB)

    Priyanto, D.G. [Atomic Energy of Canada Limited, Pinawa, MB (Canada)

    2011-07-01

    Shaft seals are components of the engineered barriers system considered for closure of a Deep Geological Repository (DGR). These seals would be installed in strategic locations of the shafts, where significant fracture zones (FZ) are located and would serve to limit upward flow of groundwater from the repository level towards the surface. This paper presents the results of hydro-mechanical (HM) numerical modelling exercises to evaluate the performance of a shaft seal using a finite element computer code, COMSOL. This study considered a variety of host geological media as part of generic assessments of system evolution in a variety of environments including five hypothetical sedimentary and crystalline host rock conditions. Four simulations of a shaft seal in different sedimentary rocks were completed, including: shale with isotropic permeability; shale with anisotropic permeability; limestone with isotropic permeability; and limestone with anisotropic permeability. The other simulation was a shaft seal in crystalline rock with isotropic permeability. Two different stages were considered in these HM simulations. Stages 1 and 2 simulated the groundwater flow into an open shaft and after installation of shaft sealing components, respectively. As expected, the models were able to simulate that installation of the shaft seal limits groundwater flow through the shaft. Based on the conditions and assumptions defined for the host media and fracture features examined in this study, the following conclusions can be drawn from the results of the numerical modelling exercises. A shaft that remained open for a longer time was beneficial with respect to delaying of seal saturation because it could reduce the groundwater flow rate around the fracture zone. Delaying saturation time indicates slower movement of the groundwater or other substances that may be transported with the groundwater. The core of the shaft seal (i.e., the bentonite-sand mixture (BSM)) became fully saturated

  14. Acoustic Emission Characteristics of Sedimentary Rocks Under High-Velocity Waterjet Impingement

    Science.gov (United States)

    Tian, Shouceng; Sheng, Mao; Li, Zhaokun; Ge, Hongkui; Li, Gensheng

    2017-10-01

    The success of waterjet drilling technology requires further insight into the rock failure mechanisms under waterjet impingement. By combining acoustic emission (AE) sensing and underwater sound recording techniques, an online system for monitoring submerged waterjet drilling has been developed. For four types of sedimentary rocks, their AE characteristics and correlations to the drilling performance have been obtained through time-frequency spectrum analysis. The area under the power spectrum density curve has been used as the indicator of AE energy. The results show that AE signals from the fluid dynamics and the rock failure are in different ranges of signal frequency. The main frequencies of the rock failure are within the higher range of 100-200 kHz, while the frequencies of the fluid dynamics are below 50 kHz. Further, there is a linear relationship between the AE energy and the drilling depth irrespective of rock type. The slope of the linear relationship is proportional to the rock strength and debris size. Furthermore, the AE-specific energy is a good indicator of the critical depth drilled by the waterjet. In conclusion, the AE characteristics on the power density and dominant frequency are capable of identifying the waterjet drilling performance on the rock materials and are correlated with the rock properties, i.e., rock strength and cutting size.

  15. Rupture Cascades in a Discrete Element Model of a Porous Sedimentary Rock

    OpenAIRE

    Kun Ferenc (1966-) (fizikus); Varga Imre; Lennartz-Sassinek, Sabine; Main, Ian G.

    2014-01-01

    We investigate the scaling properties of the sources of crackling noise in a fully-dynamic numerical model of sedimentary rocks subject to uniaxial compression. The model is initiated by filling a cylindrical container with randomly-sized spherical particles which are then connected by breakable beams. Loading at a constant strain rate the cohesive elements fail and the resulting stress transfer produces sudden bursts of correlated failures, directly analogous to the sources of acoustic emiss...

  16. Sorting out compositional trends in sedimentary rocks of the Bradbury group (Aeolis Palus), Gale crater, Mars

    Science.gov (United States)

    Siebach, K. L.; Baker, M. B.; Grotzinger, J. P.; McLennan, S. M.; Gellert, R.; Thompson, L. M.; Hurowitz, J. A.

    2017-02-01

    Sedimentary rocks are composed of detrital grains derived from source rocks, which are altered by chemical weathering, sorted during transport, and cemented during diagenesis. Fluvio-lacustrine sedimentary rocks of the Bradbury group, observed on the floor of Gale crater by the Curiosity rover during its first 860 Martian solar days, show trends in bulk chemistry that are consistent with sorting of mineral grains during transport. The Bradbury group rocks are uniquely suited for sedimentary provenance analysis because they appear to have experienced negligible cation loss (i.e., open-system chemical weathering) at the scale of the Alpha Particle X-ray Spectrometer bulk chemistry analyses based on low Chemical Index of Alteration values and successful modeling of >90% of the (volatile-free) targets as mixtures of primary igneous minerals. Significant compositional variability between targets is instead correlated to grain-size and textural characteristics of the rocks; the coarsest-grained targets are enriched in Al2O3, SiO2, and Na2O, whereas the finer-grained targets are enriched in mafic components. This is consistent with geochemical and mineralogical modeling of the segregation of coarse-grained plagioclase from finer-grained mafic minerals (e.g., olivine and pyroxenes), which would be expected from hydrodynamic sorting of the detritus from mechanical breakdown of subalkaline plagioclase-phyric basalts. While the presence of a distinctive K2O-rich stratigraphic interval shows that input from at least one distinctive alkali-feldspar-rich protolith contributed to basin fill, the dominant compositional trends in the Bradbury group are consistent with sorting of detrital minerals during transport from relatively homogeneous plagioclase-phyric basalts.

  17. Integrated techniques to evaluate the features of sedimentary rocks of archaeological areas of Sicily

    Directory of Open Access Journals (Sweden)

    Maria Brai

    2004-02-01

    Full Text Available Sicily includes a great variety of lithologies, giving a high complexity to the geologic landscape. Their prevalent lithology is sedimentary. It is well known that rocks of sedimentary origin, compared with metamorphic and volcanic deposits, can be relatively soft and hence fairly easy to model. Nevertheless, this workability advantage is a drawback for Cultural Heritage applications. In fact, these materials show a high porosity, with pore-size distributions that lead to deterioration through absorption of water. In this paper, several sedimentary rocks used in historical Cultural Heritage items of Sicily, from "Magna Graecia" to nowadays, are classified for mineralogical features, chemical composition, and for porosity. Particularly, some samples collected in quarries relevant to the archaeological sites of 41 Agrigento, Segesta and Selinunte will be considered and characterized using integrated techniques (XRD, XRF, NMR and CT. Data on samples obtained in laboratory will be compared with the relevant values measured in situ on monuments of historical-cultural interest of the quoted archaeological places.

  18. Geophysical anatomy of counter-slope scarps in sedimentary flysch rocks (Outer Western Carpathians)

    Science.gov (United States)

    Tábořík, P.; Lenart, J.; Blecha, V.; Vilhelm, J.; Turský, O.

    2017-01-01

    A multidisciplinary geophysical survey, consisting of electrical resistivity tomography (ERT), ground penetrating radar (GPR), shallow seismic refraction (SSR) and gravity survey (GS), was used to investigate the counter-slope scarps, one of the typical manifestations of the relaxed zones of rock massifs, and the possible initial stages of deep-seated landslides (DSLs). Two upper parts of the extensive DSLs within the Moravskoslezské Beskydy Mountains (Outer Western Carpathians - OWC) built by the sedimentary flysch rock were chosen as the testing sites. A combined geophysical survey on the flysch rocks was performed on both localities to enhance our present findings. The survey revealed that the ERT is able to reliably detect underground discontinuities, which are manifested at the ground surface by one of the typical landforms (tension cracks, trenches, pseudokarst sinkholes, double-crested ridges and counter-slope scarps). Previous studies suggested that bedrock discontinuities should be depicted by high-resistivity features within ERT surveying. According to SSR and GS, expected zones of weakened rock massif were not confirmed directly underneath the superficial landforms, but they were shifted. Based on the SSR and GS measurements, the depicted high-contrast transitions between high- and low-resistivity domains within the ERT profiles were newly identified as possible manifestation of bedrock discontinuities. The results of GPR measurements give only limited information on the sedimentary flysch rocks, due to shallow penetrating depth and locally strong signal attenuation. The combined results of multidisciplinary geophysical surveying confirmed an importance of employing more than one geophysical technique for integrated interpretations of measured data. Integrated interpretations of the measured geophysical data provided a new insight into massif disintegration and the geomorphic origin of the landforms related to the DSL.

  19. Dolomitization and sedimentary cyclicity of the Ordovician, Silurian, and Devonian rocks in South Estonia

    Directory of Open Access Journals (Sweden)

    Kallaste, Toivo

    2006-03-01

    Full Text Available The distribution and composition of dolomitized rocks and stoichiometry of dolomite in southern Estonia in the Ordovician, Silurian, and Devonian were studied on the background of the facies, sedimentary cyclicity (nine shallowing-up cycles, and evolution of the palaeobasins. The composition of rocks and lattice parameters of dolomite were investigated using the X-ray diffraction, X-ray fluorescence, titration and gravimetric analyses, and porosity measurements. The formation of dolostones is directly determined by the cyclic evolution of palaeobasins. Dolomitized rocks belong to the shallow-water inner shelf or tidal/lagoonal facies belt of regressive phases of sedimentary cycles. Sediments of the deep shelf/transitional environment and transgressive phases are not dolomitized. The most stoichiometric is secondary replacive dolomite of Silurian and upper Ordovician dolostones, formed during the early diagenesis of normal-marine (saline shallow-shelf calcitic sediments. The content of insoluble residue does not affect the stoichiometry. The changes in lattice parameters are induced by the Ca/Mg ratio in the dolomite lattice. The dolomite of the dolostones contacting limestone or containing calcite has an expanded lattice. The primary (syngenetic dolostone of the lagoonal or tidal flat belt has also an expanded lattice. No dolomitizing effect of the waters of the Devonian palaeobasin on the underlying rocks was revealed. The whole data set of the studied dolostones is consistent with the marine water environment in the palaeobasin at the corresponding time and shows no sign of the inflow of external fluids. It suggests that the microbial model of dolomite formation may characterize the Ordovician, Silurian, and Devonian in southern Estonia. The occurrence of dolostones between undolomitized rocks limits the time of dolomitization to the early diagenetic stage.

  20. An Aquatic Journey toward Aeolis Mons (Mount Sharp): Sedimentary Rock Evidence observed by Mars Science Laboratory

    Science.gov (United States)

    Gupta, Sanjeev; Edgar, Lauren; Williams, Rebecca; Rubin, David; Yingst, Aileen; Lewis, Kevin; Kocurek, Gary; Anderson, Ryan; Dromart, Gilles; Edgett, Ken; Hardgrove, Craig; Kah, Linda; Mangold, Nicolas; Milliken, Ralph; Minitti, Michelle; Palucis, Marisa; Rice, Melissa; Stack, Katie; Sumner, Dawn; Williford, Ken

    2014-05-01

    Since leaving Yellowknife Bay (summer 2013), Mars Science Laboratory Curiosity has investigated a number of key outcrops as it traverses along the Rapid Transit Route toward the entry point to begin its investigations of the extensive rock outcrops at the base of Mount Sharp. Rover observations are characterizing the variability of lithologies and sedimentary facies along the traverse and establishing stratigraphic relationships with the aim of reconstructing depositional processes and palaeoenvironments. Here, we report on sedimentological and stratigraphic observations based on images from the Mastcam and MAHLI instruments at Shaler and the Darwin waypoint. The informally named Shaler outcrop, which forms part of the Glenelg member of the Yellowknife Bay formation [1] is remarkable for the preservation of a rich suite of sedimentary structures and architecture, and was investigated on sols 120-121 and 309-324. The outcrop forms a pebbly sandstone body that is ~0.7 m thick and extends for up to 20 m. Shaler is largely characterized by pebbly sandstone facies showing well-developed decimeter-scale trough cross-stratification. Bedding geometries indicate sub-critical angles of climb, resulting in preservation of only the lee slope deposits. The grain size, and the presence and scale of cross-stratification imply sediment transport and deposition by unidirectional currents in a fluvial sedimentary environment. Curiosity investigated the informally named Darwin waypoint between sols 390 and 401, making detailed Mastcam and MAHLI observations at two separate locations. The Darwin outcrop comprises light-toned sandstone beds separated by darker pebbly sandstones. MAHLI observations permit differentiation of distinct sedimentary facies. The Altar Mountain facies is a poorly sorted pebbly sandstone that is rich in fine pebbles. Pebbles are sub-angular to sub-rounded in shape and show no preferred orientation or fabric. Pebbles and sand grains show clast-to-clast contacts

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

    Science.gov (United States)

    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

  2. Variety and complexity in the mound of sedimentary rock in Gale Crater, Mars

    Science.gov (United States)

    Edgett, K. S.; Malin, M. C.

    2011-12-01

    NASA's Mars Science Laboratory rover, Curiosity, will be used to explore a portion of the lower stratigraphic record of the northwest side of a mound of layered rock ˜5 km thick in the 155 km-diameter Gale Crater. The rock materials are of a sedimentary origin, though the proportions of clastic sediment, tephra, and chemical precipitates are presently unknown. The mound is usually described as having lower and upper units separated by an erosional unconformity. However, some investigators recognize that it is considerably more complex. The stratigraphy displays vertical and lateral complexity; multiple erosional unconformities; filled, buried, interbedded, and exhumed or partly exhumed impact craters; evidence for deposition along the base of the mound followed by retreat of less-resistant rocks and abandonment of erosion-resistant materials shed from the mound; lithified sediments deposited at the mouths of streams that cut mound rock; inversion of intra-canyon stream channel sediment; and widening of canyons. On the northeast side of the mound there are landslide deposits, shed from the mound, that contain large blocks (10s to 100s of m) of layered rock in various orientations. The mound's highest feature does not exhibit layering and has been interpreted by some as being Gale's impact-generated central peak. However, its highest elevation exceeds that of most of the crater rim, an observation inconsistent with central peaks (where they occur at all) in martian craters of diameters similar to Gale. The layered materials that occur highest in the mound are also at elevations that exceed most of the crater rim; these exhibit repeated stratal packages that drape previously-eroded mound topography; they produce boulders as they erode, attesting to their lithified nature and requiring that a lithification process occurred in materials located ≥ 5 km above the deepest part of Gale. The lower mound strata, including the Curiosity field site, are diverse materials

  3. Comparison of methods for measuring vertical hydraulic properties in a sedimentary rock aquifer

    Science.gov (United States)

    Novakowski, Kent; Worley, Jessica

    2013-04-01

    The characterization of groundwater flow in fractured bedrock aquifers is presently based on a variety of hydraulic testing methods. Pumping tests are often employed, the interpretation of which are based on models derived for porous media environments that do not fully represent the complexities of fractured rock settings. In this paper, we measure aquifer properties using a variety of testing methods in order to evaluate which methods are best capable of producing reliable parameter estimates. The study was performed in a fractured sedimentary rock aquifer using four different field methods: constant head tests conducted using a straddle-packer system, pulse interference tests conducted under open-hole conditions, 12-hour isolated interval pumping tests and 48-hour open-hole pumping tests. Using the results of the constant head tests as the most reliable method for estimation of hydraulic conductivity and specific yield, the results obtained using the other three methods were compared with particular emphasis on the estimation of vertical hydraulic parameters in this setting. The effects of test measurement scale on hydraulic parameter estimates were also investigated. Evaluation of the open-hole pumping test data was performed using an analytical model that accommodates multiple horizontal fractures and a connection to a free surface boundary. The comparison shows that estimates of horizontal hydraulic conductivity were not dependent on test method with all methods providing equivalent results. Open-well pumping tests, however, were found not to reliably estimate values of vertical hydraulic conductivity and specific yield for this setting. Alternatively, pulse interference tests conducted under open-hole conditions may offer a less time-intensive option to constant head injection tests for determining vertical hydraulic parameters in a sedimentary rock setting.

  4. Seawater as the source of minor elements in black shales, phosphorites and other sedimentary rocks

    Science.gov (United States)

    Piper, D.Z.

    1994-01-01

    Many of the minor elements in seawater today have a concentration-depth profile similar to that of the biologically essential nutrients, NO-3 and PO3-4. They show a relative depletion in the photic zone and enrichment in the deep ocean. The difference between their surface- and deep-ocean values, normalized to the change in PO3-4, approaches the average of measured minor-element: P ratios in marine plankton, although individual analyses of the latter show extreme scatter for a variety of reasons. Despite this scatter in the minor-element analyses of plankton, agreement between the two sets of data shows unequivocally that an important marine flux of many minor elements through the ocean is in the form of biogenic matter, with a composition approaching that of plankton. This interpretation is further supported by sediment studies, particularly of sediments which accumulate in shelf-slope environments where biological productivity in the photic zone is exceptionally high and organic carbon contents of the underlying sediment elevated. The interelement relations observed for some of these sediments approach the average values of plankton. These same interelement relations are observed in many marine sedimentary rocks such as metalliferous black shales and phosphorites, rocks which have a high content of marine fractions (e.g., organic matter, apatite, biogenic silica and carbonates). Many previous studies of the geochemistry of these rocks have concluded that local hydrothermal activity, and/or seawater with an elemental content different from that of the modern ocean, was required to account for their minor-element contents. However, the similarity in several of the minor-element ratios in many of these formations to minor-element ratios in modern plankton demonstrates that these sedimentary rocks accumulated in environments whose marine chemistry was virtually identical to that seen on continental shelf-slopes, or in marginal seas, of the ocean today. The

  5. Clay, Water, and Salt: Controls on the Permeability of Fine-Grained Sedimentary Rocks.

    Science.gov (United States)

    Bourg, Ian C; Ajo-Franklin, Jonathan B

    2017-09-19

    The ability to predict the permeability of fine-grained soils, sediments, and sedimentary rocks is a fundamental challenge in the geosciences with potentially transformative implications in subsurface hydrology. In particular, fine-grained sedimentary rocks (shale, mudstone) constitute about two-thirds of the sedimentary rock mass and play important roles in three energy technologies: petroleum geology, geologic carbon sequestration, and radioactive waste management. The problem is a challenging one that requires understanding the properties of complex natural porous media on several length scales. One inherent length scale, referred to hereafter as the mesoscale, is associated with the assemblages of large grains of quartz, feldspar, and carbonates over distances of tens of micrometers. Its importance is highlighted by the existence of a threshold in the core scale mechanical properties and regional scale energy uses of shale formations at a clay content X clay ≈ 1/3, as predicted by an ideal packing model where a fine-grained clay matrix fills the gaps between the larger grains. A second important length scale, referred to hereafter as the nanoscale, is associated with the aggregation and swelling of clay particles (in particular, smectite clay minerals) over distances of tens of nanometers. Mesoscale phenomena that influence permeability are primarily mechanical and include, for example, the ability of contacts between large grains to prevent the compaction of the clay matrix. Nanoscale phenomena that influence permeability tend to be chemomechanical in nature, because they involve strong impacts of aqueous chemistry on clay swelling. The second length scale remains much less well characterized than the first, because of the inherent challenges associated with the study of strongly coupled nanoscale phenomena. Advanced models of the nanoscale properties of fine-grained media rely predominantly on the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, a mean field

  6. Numerical model of halite precipitation in porous sedimentary rocks adjacent to salt diapirs

    Science.gov (United States)

    Li, Shiyuan; Reuning, Lars; Marquart, Gabriele; Wang, Yan; Zhao, Pengyun

    2017-10-01

    Salt diapirs are commonly seen in the North Sea. Below the Zechstein Group exist possibly overpressured salt-anhydrite formations. One explanation as to the salt precipitation in areas with salt diapirs is that salt cementation is thermally driven and occurs strongly in places adjacent to salt diapirs. This paper assumes that the sealing effect of the cap rock above the salt formations is compromised and overpressured fluids, carrying dissolved minerals such as anhydrite (CaSO4) and salt mineral components (NaCl of halite), flow into the porous sedimentary layers above the salt formations. Additionally, a salt-diapir-like structure is assumed to be at one side of the model. The numerical flow and heat transport simulator SHEMAT-Suite was developed and applied to calculating the concentrations of species, and dissolution and precipitation amounts. Results show that the overpressured salt-anhydrite formations have higher pressure heads and the species elements sodium and chlorite are transported into porous sediment rocks through water influx (saturated brine). Halite can precipitate as brine with sodium and chlorite ions flows to the cooler environment. Salt cementation of reservoir rocks leads to decreasing porosity and permeability near salt domes, and cementation of reservoir formations decreases with growing distance to the salt diapir. The proposed approach in this paper can also be used to evaluate precipitation relevant to scaling problems in geothermal engineering.

  7. Metal accumulation in soils derived from volcano-sedimentary rocks, Rio Itapicuru Greenstone Belt, northeastern Brazil.

    Science.gov (United States)

    Dos Santos, Laíse Milena Ribeiro; Gloaguen, Thomas Vincent; Fadigas, Francisco de Souza; Chaves, Joselisa Maria; Martins, Tamires Moraes Oliveira

    2017-12-01

    Many countries and some Brazilian regions have defined the guideline values for metals in soils. However, the local geological features may be so heterogeneous that global or even regional guideline values cannot be applied. The Greenstone Belts are worldwide geological formations of vast extension, containing mineralization of various metals (e.g., Au, Cr, Ni, and Ag). Natural concentrations of soils must be known to correctly assess the impact of mining. We studied the soils of the Rio Itapicuru Greenstone Belt (RIGB), of Paleoproterozoic age, sampling at 24 sites (0-0.20m) in the areas not or minimally human impacted, equally distributed in the three units of the RIGB: Volcanic Mafic Unit (VMU), Volcanic Felsic Unit (VFU), and Volcano-clastic Sedimentary Unit (SU). The natural pseudo-total concentrations of Cr, Ni, Cu, Zn, Pb, Fe, and Mn were obtained by acid digestion (EPA3050b) both in the soil and the particle-size fractions (sand and clay+silt). The concentrations of metals in RIGB soils, especially Cr and Ni, are generally higher than those reported for other regions of Brazil or other countries. Even the sedimentary soils have relatively high metal values, naturally contaminated by the VMU of the RIGB; a potential impact on Mesozoic and Cenozoic sedimentary rocks located near the study region is highly expected. Metals are concentrated (80%) in the fine particle-size fraction, implying an easy availability through surface transport (wind and runoff). We introduced a new index, called the Fe-independent accumulation factor - AF -Fe , which reveals that 90-98% of the dynamics of the trace metals is associated with the iron geochemical cycle. We primarily conclude that determining the guideline values for different soil classes in variable geological/geochemical environment and under semiarid climate is meaningless: the concentration of metals in soils is clearly more related to the source material than to the pedogenesis processes. Copyright © 2017 Elsevier

  8. Provenance and palaeogeographic implications of Eocene-Oligocene sedimentary rocks in the northwestern Basin and Range

    Science.gov (United States)

    Egger, A.E.; Colgan, J.P.; York, C.

    2009-01-01

    A thick sequence of uppermost Eocene to lower Oligocene volcaniclastic and sedimentary rocks is exposed at the base of the Warner Range in northeastern California. This isolated exposure provides insight into the palaeogeographic setting of the northwestern Basin and Range during this time period. Significant thinning of the unit over 35km of lateral exposure and predominantly volcanic clast compositions suggest that the sequence was deposited in an alluvial plain adjacent to a volcanic arc. Palaeocurrent indicators in the conglomerates define a NNE transport direction. Detrital zircon analysis on coarse sandstones and dating of individual granite cobbles show a range of ages consistent with a local, volcanic source area primarily from the SSW with some far-travelled input from northern Nevada; the far-travelled component increases in influence as the unit thins to the north. Comparison with other sedimentary sequences of Eocene age and integration with palaeofloral and geophysical data help to define drainage divides, and suggest that this sequence accumulated in a relatively isolated, intra-arc basin. This localized accumulation differs markedly from contemporaneous drainages to the south that transported material westwards from central Nevada to the palaeoshoreline, and suggests that ongoing volcanism had a strong influence on palaeogeography in this region during the Eocene and Oligocene.

  9. Thermal conductivity of sedimentary rocks - selected methodological, mineralogical and textural studies

    Energy Technology Data Exchange (ETDEWEB)

    Midttoemme, Kirsti

    1997-12-31

    The thermal conductivity of sedimentary rocks is an important parameter in basin modelling as the main parameter controlling the temperature within a sedimentary basin. This thesis presents measured thermal conductivities, mainly on clay- and mudstone. The measured values are compared with values obtained by using thermal conductivity models. Some new thermal conductivity models are developed based on the measured values. The values obtained are less than most previously published values. In a study of unconsolidated sediments a constant deviation was found between thermal conductivities measured with a needle probe and a divided bas apparatus. Accepted thermal conductivity models based on the geometric mean model fail to predict the thermal conductivity of clay- and mudstone. Despite this, models based on the geometric mean model, where the effect of porosity is taken account of by the geometric mean equation, seem to be the best. Existing models underestimate the textural influence on the thermal conductivity of clay- and mudstone. The grain size was found to influence the thermal conductivity of artificial quartz samples. The clay mineral content seems to be a point of uncertainty in both measuring and modelling thermal conductivity. A good universal thermal conductivity model must include many mineralogical and textural factors. Since this is difficult, different models restricted to specific sediment types and textures are suggested to be the best solution to obtain realistic estimates applicable in basin modelling. 243 refs., 64 figs., 31 tabs.

  10. Geoconservation evaluation of the sites of Miocene sedimentary rocks in the quarries of north-eastern Slovenia

    Directory of Open Access Journals (Sweden)

    Mojca Planjšek

    2002-12-01

    Full Text Available The article deals with the sites of Miocene sedimentary rocks in north-eastern Slovenia. Due to dense vegetation cover and consequently rare rock outcrops mostly abandoned quarries were elaborated. According to evaluation criteria defined by Nature Conservation Act and Decree on the categories of valuable natural features, out of 28 examined locations 6 were selected as important from the nature conservation point of view. These sites contain mainly the fossilferous lithothamnian limestone and they are proposed to be listed as valuable geological natural features. The quarries Osek – oolite limestone and sandstone site and Zgornji Duplek 1 –lithothamnian limestone siteare proposed as geological natural values of national importance. The lithothamnian rocks used to be importantbuilding stone. Nowadays we find it in some of important cultural monuments like castles, churches and other cultural monuments. In this respect some of the sites of Miocene sedimentary rocks have significant cultural value as well.

  11. Factors controlling enrichment of vanadium and nickel in the bitumen of organic sedimentary rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lewan, M.D. (Amoco Production Co., Tulsa, OK); Maynard, J.B.

    1982-12-01

    Enriched concentrations of vanadium and nickel have been noted in a variety of naturally occurring organic substances including crude oils, asphalts, and organic matter in some sedimentary rocks. Vanadium and nickel concentrations in bitumens extracted from a variety of organic sedimentary rock types of different geological ages and geographical areas range from less than 0.2 to 4760 ppm and less than 7 to 1240 ppm, respectively. Vanadium concentrations showed a polymodal frequency distribution. The concentrations of these two metals showed no significant correlations with bitumen content, organic carbon content, or proportionality between bitumen and organic carbon contents. Enriched vanadium and nickel concentrations greater than 100 ppm are only observed in bitumens that are associated with Type II and Type I kerogens. Conversely, bitumens associated with Type III kerogens contained vanadium and nickel concentrations less than 100 ppm. The high stability of vanadium and nickel in crude oils, asphalts, and bitumens suggest that they occur in tetrapyrrole complexes. The complexes may occur as free molecules or assimulated subunits in macromolecules within the bitumen. Vanadium and nickel are preferentially concentrated in tetrapyrrole complexes because of their availability in anaerobic systems, small atomic radii, and favorable electron configurations. The potential for an organic sediment to be enriched in these two metals depends upon the amount of tetrapyrroles preserved in its organic matter. Tetrapyrrole preservation preferentially decreases in organic matter as exposure time to aerobic conditions increases. The potential for vanadium and nickel enrichment is therefore the highest in organic matter derived from algae that encountered anaerobic conditions early in their depositional history.

  12. New approaches in the indirect quantification of thermal rock properties in sedimentary basins: the well-log perspective

    Science.gov (United States)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2016-04-01

    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 sedimentary rocks derived from data provided by standard geophysical well logs. The approach is based on a data set of synthetic sedimentary 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 10.1093/gji/ggv403

  13. Deformation properties of sedimentary rocks in the process of underground coal gasification

    Directory of Open Access Journals (Sweden)

    Mirosława Bukowska

    2015-01-01

    Full Text Available The article presents results of research into changes in deformation properties of rocks, under influence of temperature, during the process of underground coal gasification. Samples of carboniferous sedimentary rocks (claystones and sandstones, collected in different areas of Upper Silesian Coal Basin (GZW, were heated at the temperature of between 100 and 1000–1200 °C, and then subjected to uniaxial compression tests to obtain a full stress-strain curves of the samples and determine values of residual strain and Poisson's ratio. To compare the obtained values of deformation parameters of rocks, tested in dry-air state and after heating in a given range of temperature, normalised values of residual strain and Poisson's ratio were determined. Based on them, coefficient of influence of temperature on tested deformation parameters was determined. The obtained values of the coefficient can be applied in mining practice to forecast deformability of gangue during underground coal gasification, when in the direct surrounding of a georeactor there are claystones or sandstones. The obtained results were analysed based on classification of uniaxial compression strength of GZW gangue, which formed the basis for dividing claystones and sandstones into very low, low, medium and high uniaxial compression strength rocks. Based on the conducted tests it was concluded that the influence of uniaxial compression strength on the value of residual strain, unlike the influence of grain size of sandstones, is unambiguous within the range of changes in the parameter. Among claystones changes in the value of Poisson's ratio depending on their initial strength were observed. Sandstones of different grain size either increased or decreased the value of Poisson's ratio in comparison with the value determined at room temperature in dry-air conditions.

  14. Discrimination between Sedimentary Rocks from Close-Range Visible and Very-Near-Infrared Images.

    Directory of Open Access Journals (Sweden)

    Susana Del Pozo

    Full Text Available Variation in the mineral composition of rocks results in a change of their spectral response capable of being studied by imaging spectroscopy. This paper proposes the use of a low-cost handy sensor, a calibrated visible-very near infrared (VIS-VNIR multispectral camera for the recognition of different geological formations. The spectral data was recorded by a Tetracam Mini-MCA-6 camera mounted on a field-based platform covering six bands in the spectral range of 0.530-0.801 µm. Twelve sedimentary formations were selected in the Rhône-Alpes region (France to analyse the discrimination potential of this camera for rock types and close-range mapping applications. After proper corrections and data processing, a supervised classification of the multispectral data was performed trying to distinguish four classes: limestones, marlstones, vegetation and shadows. After a maximum-likelihood classification, results confirmed that this camera can be efficiently exploited to map limestone-marlstone alternations in geological formations with this mineral composition.

  15. Veneers, rinds, and fracture fills: Relatively late alteration of sedimentary rocks at Meridiani Planum, Mars

    Science.gov (United States)

    Knoll, A.H.; Jolliff, B.L.; Farrand, W. H.; Bell, J.F.; Clark, B. C.; Gellert, Ralf; Golombek, M.P.; Grotzinger, J.P.; Herkenhoff, K. E.; Johson, J.R.; McLennam, S.M.; Morris, Robert; Squyres, S. W.; Sullivan, R.; Tosca, N.J.; Yen, A.; Learner, Z.

    2008-01-01

    Veneers and thicker rinds that coat outcrop surfaces and partially cemented fracture fills formed perpendicular to bedding document relatively late stage alteration of ancient sedimentary rocks at Meridiani Planum, Mars. The chemistry of submillimeter thick, buff-colored veneers reflects multiple processes at work since the establishment of the current plains surface. Veneer composition is dominated by the mixing of silicate-rich dust and sulfate-rich outcrop surface, but it has also been influenced by mineral precipitation, including NaCl, and possibly by limited physical or chemical weathering of sulfate minerals. Competing processes of chemical alteration (perhaps mediated by thin films of water or water vapor beneath blanketing soils) and sandblasting of exposed outcrop surfaces determine the current distribution of veneers. Dark-toned rinds several millimeters thick reflect more extensive surface alteration but also indicate combined dust admixture, halite precipitation, and possible minor sulfate removal. Cemented fracture fills that are differentially resistant to erosion occur along the margins of linear fracture systems possibly related to impact. These appear to reflect limited groundwater activity along the margins of fractures, cementing mechanically introduced fill derived principally from outcrop rocks. The limited thickness and spatial distribution of these three features suggest that aqueous activity has been rare and transient or has operated at exceedingly low rates during the protracted interval since outcropping Meridiani strata were exposed on the plains surface. Copyright 2008 by the American Geophysical Union.

  16. Discrimination between Sedimentary Rocks from Close-Range Visible and Very-Near-Infrared Images.

    Science.gov (United States)

    Del Pozo, Susana; Lindenbergh, Roderik; Rodríguez-Gonzálvez, Pablo; Kees Blom, Jan; González-Aguilera, Diego

    2015-01-01

    Variation in the mineral composition of rocks results in a change of their spectral response capable of being studied by imaging spectroscopy. This paper proposes the use of a low-cost handy sensor, a calibrated visible-very near infrared (VIS-VNIR) multispectral camera for the recognition of different geological formations. The spectral data was recorded by a Tetracam Mini-MCA-6 camera mounted on a field-based platform covering six bands in the spectral range of 0.530-0.801 µm. Twelve sedimentary formations were selected in the Rhône-Alpes region (France) to analyse the discrimination potential of this camera for rock types and close-range mapping applications. After proper corrections and data processing, a supervised classification of the multispectral data was performed trying to distinguish four classes: limestones, marlstones, vegetation and shadows. After a maximum-likelihood classification, results confirmed that this camera can be efficiently exploited to map limestone-marlstone alternations in geological formations with this mineral composition.

  17. Paleomagnetic Evidence for 'Oroclinal' Rotation in the Central Japan Arc from Early Miocene Sedimentary Rocks

    Science.gov (United States)

    Hoshi, H.; Sako, K.; Namikawa, T.; Ando, Y.

    2013-12-01

    In this study we focus on the general curvilinear trend of geologic zones (mainly accretionary complexes) in the central Japan arc. This feature is best represented by the Median Tectonic Line (MTL), a major boundary fault between the Sanbagawa high-P/T and Ryoke low-P/T metamorphic belts. Previous paleomagnetic data imply that the curvature is of 'oroclinal' origin, that is, the curved system was originally straight and formed after the accretionary processes and metamorphism. In order to quantitatively assess this possibility, we have carried out a paleomagnetic study for Early Miocene sedimentary rocks from two areas (Morozaki in Aichi Prefecture and Tomikusa in Nagano Prefecture) in central Japan. In Morozaki, oriented cores were collected at 22 sites from felsic tuff and siltstone beds of the Himaka Formation, which is the lowermost formation of the sedimentary sequence in this area. In Tomikusa, cores were taken at 24 sites from various lithologies of the Tomikusa Group. Rock specimens were subjected to stepwise alternating-field or thermal demagnetization in order to extract characteristic remanent magnetization (ChRM) components. Rock magnetic experiments suggest that ChRMs are carried primarily by magnetite. The Himaka Formation sites have reverse-polarity ChRM directions, and we consider this formation to be correlative to Chronozone C5Dr (18.056-17.533 Ma). The Tomikusa Group indicates both normal and reverse polarities and can be correlated to Chronozone C5D (18.056-17.235 Ma). Mean paleomagnetic directions for the two areas were determined and, together with existing paleomagnetic data from other areas, they were used for a paleomagnetic orocline test with a declination-strike diagram. Our result strongly suggests that the geologic zones and boundary faults (including the MTL) in the central Japan arc was straight before 18 Ma. We suggest that the oroclinal rotation results from a combination of the clockwise rotation of the southwestern Japan arc and

  18. Chemistry and texture of the rocks at Rocknest, Gale Crater: Evidence for sedimentary origin and diagenetic alteration

    Science.gov (United States)

    Blaney, Diana L.; Wiens, R.C.; Maurice, S.; Clegg, S.M.; Anderson, Ryan; Kah, L.C.; Le Mouélic, S.; Ollila, A.; Bridges, N.; Tokar, R.; Berger, G.; Bridges, J.C.; Cousin, A.; Clark, B.; Dyar, M.D.; King, P.L.; Lanza, N.; Mangold, N.; Meslin, P.-Y.; Newsom, H.; Schroder, S.; Rowland, S.; Johnson, J.; Edgar, L.; Gasnault, O.; Forni, O.; Schmidt, M.; Goetz, W.; Stack, K.; Sumner, D.; Fisk, M.; Madsen, M.B.

    2014-01-01

    A suite of eight rocks analyzed by the Curiosity Rover while it was stopped at the Rocknest sand ripple shows the greatest chemical divergence of any potentially sedimentary rocks analyzed in the early part of the mission. Relative to average Martian soil and to the stratigraphically lower units encountered as part of the Yellowknife Bay formation, these rocks are significantly depleted in MgO, with a mean of 1.3 wt %, and high in Fe, averaging over 20 wt % FeOT, with values between 15 and 26 wt % FeOT. The variable iron and low magnesium and rock texture make it unlikely that these are igneous rocks. Rock surface textures range from rough to smooth, can be pitted or grooved, and show various degrees of wind erosion. Some rocks display poorly defined layering while others seem to show possible fractures. Narrow vertical voids are present in Rocknest 3, one of the rocks showing the strongest layering. Rocks in the vicinity of Rocknest may have undergone some diagenesis similar to other rocks in the Yellowknife Bay Formation as indicated by the presence of soluble calcium phases. The most reasonable scenario is that fine-grained sediments, potentially a mixture of feldspar-rich rocks from Bradbury Rise and normal Martian soil, were lithified together by an iron-rich cement.

  19. The geological and microbiological controls on the enrichment of Se and Te in sedimentary rocks

    Science.gov (United States)

    Bullock, Liam; Parnell, John; Armstrong, Joseph; Boyce, Adrian; Perez, Magali

    2017-04-01

    sequestered out of seawater into pyritic shales at a higher rate than into crusts. Se enrichment in roll-fronts relates to the initial mobilisation of trace elements in oxidised conditions, and later precipitation downgradient in reduced conditions. Results highlight the potential for sedimentary types of Se- and Te-bearing deposits. The enrichment of elements of high value for future technologies in sedimentary rocks deserve careful assessment for potential future resources, and should be monitored during exploration and mobilisation due to the potential contamination effects. This work forms part of the NERC-funded 'Security of Supply of Mineral Resources' project, which aims to detail the science needed to sustain the security of supply of strategic minerals in a changing environment.

  20. Coercivity Distributions of Soft-Magnetic Components and Their Occurrence in Sediments ANS Sedimentary Rocks

    Science.gov (United States)

    Egli, R.; Spassov, S.; Heller, F.

    2003-12-01

    The analysis of magnetization curves with model functions is a valuable tool for identifying magnetic mineral sources in sediments and sedimentary rocks. The method is limited by two main factors: the ability of the model function in reproducing appropriately the magnetic properties of an individual component, and its extreme sensitivity to measurement errors. Both factors influence the number of components, which are needed to fit a magnetization curve within the measurement error. Recent investigations on the shape of coercivity distributions (Heslop, 2003; Egli 2003) support the use of model functions introduced by Egli (2003). Extremely detailed measurements of alternating field (AF) demagnetisation curves of isothermal (IRM) and anhysteretic (ARM) remanent magnetizations have been performed on a wide variety of sediments and sedimentary rocks including sediments from rivers, lakes and oceans, recent soils, paleosols, loesses, red clays, limestones and also on atmospheric dusts, urban pollution and magnetotactic bacteria. The component analysis allowed the identification of several magnetic components with specific properties, which reflect different magnetic mineral sources: extracellular, bacterial and pedogenic magnetite, lithogenic minerals transported by water or in air, and magnetic minerals associated to anthropogenic pollution sources. Each magnetic component is described by nine parameters: four for the shape of the IRM, four for the shape of the ARM coercivity distribution, and one for the ratio of the ARM to the IRM. By comparing similar components occurring in different samples, empirical relations can be established between different parameters, which reflect fundamental physical processes that control the shape of coercivity distributions. As a consequence, only four parameters, so-called magnetic fingerprints, are necessary to characterise a magnetic component. The effect of environmental changes on the magnetic properties of specific magnetic

  1. Sedimentary Environment and Geochemical Characteristics of Source Rocks from Later Carboniferous and Middle Permian in Santanghu Basin, NW China

    Science.gov (United States)

    Nan, Yun; Liu, Yiqun; Li, Zhexuan; Zhang, Qiao

    2018-01-01

    There is a long-term controversy on sedimentary environment of Late Carboniferous-Permian in Santanghu Basin. In this paper, we study on the geochemical characteristics of source rocks from Harjiawu Formation of Upper Carboniferous and Lucaogou Formation of Middle Permian in Santanghu Basin. The results show that the abundance and maturity of organic matter of source rocks in Harjiawu Formation are both high, which shows excellent source rocks. In contrast, the abundance of organic matter from source rocks in Lucaogou Formation is relatively low and the maturity of organic matter is between immature and mature, which suggests good-excellent source rocks. The organic geochemical characteristics indicate the freshwater lacustrine environment of Late Carboniferous, while Lucaogou Formation is the high salinity lacustrine environment. In addition, magmatic-hydrothermal activity may result in the water salinization of Permian.

  2. Using Resin-Based 3D Printing to Build Geometrically Accurate Proxies of Porous Sedimentary Rocks.

    Science.gov (United States)

    Ishutov, Sergey; Hasiuk, Franciszek J; Jobe, Dawn; Agar, Susan

    2017-09-28

    Three-dimensional (3D) printing is capable of transforming intricate digital models into tangible objects, allowing geoscientists to replicate the geometry of 3D pore networks of sedimentary rocks. We provide a refined method for building scalable pore-network models ("proxies") using stereolithography 3D printing that can be used in repeated flow experiments (e.g., core flooding, permeametry, porosimetry). Typically, this workflow involves two steps, model design and 3D printing. In this study, we explore how the addition of post-processing and validation can reduce uncertainty in the 3D-printed proxy accuracy (difference of proxy geometry from the digital model). Post-processing is a multi-step cleaning of porous proxies involving pressurized ethanol flushing and oven drying. Proxies are validated by: (1) helium porosimetry and (2) digital measurements of porosity from thin-section images of 3D-printed proxies. 3D printer resolution was determined by measuring the smallest open channel in 3D-printed "gap test" wafers. This resolution (400 µm) was insufficient to build porosity of Fontainebleau sandstone (∼13%) from computed tomography data at the sample's natural scale, so proxies were printed at 15-, 23-, and 30-fold magnifications to validate the workflow. Helium porosities of the 3D-printed proxies differed from digital calculations by up to 7% points. Results improved after pressurized flushing with ethanol (e.g., porosity difference reduced to ∼1% point), though uncertainties remain regarding the nature of sub-micron "artifact" pores imparted by the 3D printing process. This study shows the benefits of including post-processing and validation in any workflow to produce porous rock proxies. © 2017, National Ground Water Association.

  3. Diffusive separation of noble gases and noble gas abundance patterns in sedimentary rocks

    Energy Technology Data Exchange (ETDEWEB)

    Torgersen, T.; Kennedy, B.M.; van Soest, M.C.

    2004-06-14

    The mechanisms responsible for noble gas concentrations, abundance patterns, and strong retentivity in sedimentary lithologies remain poorly explained. Diffusion-controlled fractionation of noble gases is modeled and examined as an explanation for the absolute and relative abundances of noble gases observed in sediments. Since the physical properties of the noble gases are strong functions of atomic mass, the individual diffusion coefficients, adsorption coefficients and atomic radii combine to impede heavy noble gas (Xe) diffusion relative to light noble gas (Ne) diffusion. Filling of lithic grains/half-spaces by diffusive processes thus produces Ne enrichments in the early and middle stages of the filling process with F(Ne) values similar to that observed in volcanic glasses. Emptying lithic grains/half-spaces produces a Xe-enriched residual in the late (but not final) stages of the process producing F(Xe) values similar to that observed in shales. 'Exotic but unexceptional' shales that exhibit both F(Ne) and F(Xe) enrichments can be produced by incomplete emptying followed by incomplete filling. This mechanism is consistent with literature reported noble gas abundance patterns but may still require a separate mechanism for strong retention. A system of labyrinths-with-constrictions and/or C-, Si-nanotubes when combined with simple adsorption can result in stronger diffusive separation and non-steady-state enrichments that persist for longer times. Enhanced adsorption to multiple C atoms inside C-nanotubes as well as dangling functional groups closing the ends of nanotubes can provide potential mechanisms for 'strong retention'. We need new methods of examining noble gases in rocks to determine the role and function of angstrom-scale structures in both the diffusive enrichment process and the 'strong retention' process for noble gas abundances in terrestrial rocks.

  4. Depositional Environment of Fine-Grained Sedimentary Rocks of the Sinamar Formation, Muara Bungo, Jambi

    Directory of Open Access Journals (Sweden)

    M. Heri Hermiyanto Zajuli

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i1.153The research area is situated in the northwestern side of South Sumatra Basin, which is a part of Muara Bungo Regency, Jambi Province. The Oligocene Sinamar Formation consists of shale, claystone, mudstone, sandstone, conglomeratic sandstone, and coal-seam intercalations. This research was focused on fine sedimentary rock of Sinamar Formation, such as shale, claystone, and mudstone. Primary data were collected from SNM boreholes which have depths varying from 75 m up to 200 m, and outcrops that were analyzed by organic petrographic method, gas chromatography-mass spectrometry (GC-MS of normal alkanes including isoprenoids, and sterane. The dominant maceral group is exinite, composed of alginite (3.4 - 18%, and resinite (1.6 - 5.6%, while vitrinite maceral consists of tellocolinite 0.4 - 0.6%, desmocollinite 0.4%, and vitrodetrinite 8.4 - 16.6%. Organic petrography and biomarker analyses show that organic materials of shales were derived from high plants and algae especially Botrycoccus species. Botrycoccus and fresh water fish fossil, found in the shale indicate a lacustrine environment.

  5. Sedimentary petrology of oil well rock cores; Petrologia sedimentaria de nucleos de rocas de pozos petroleros

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo M, Georgina; Paredes S, Adriana [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    At the request of PEMEX Exploration and Production (PEP), in the area of Geology of the Gerencia de Geotermia, the necessary methodology has been integrated to carry out the geologic characterization of cores obtained during the oil well drilling. The integrated studies have been of utility for PEMEX, because they provide detailed information on the processes, conditions of deposition and diagenesis that occur in sedimentary rocks. On the other hand, this geologic information contributes to the update of the geologic model of the field in study. [Spanish] A solicitud de PEMEX Exploracion y Produccion (PEP), en el area de Geologia de la Gerencia de Geotermia, se ha integrado la metodologia necesaria para llevar a cabo la caracterizacion geologica de nucleos obtenidos durante la perforacion de pozos petroleros. Los estudios integrados han sido de utilidad para PEMEX, pues proporcionan informacion detallada sobre los procesos, condiciones de depositacion y diagenesis que ocurren en rocas sedimentarias. Por otro lado, esta informacion geologica contribuye a la actualizacion del modelo geologico del campo en estudio.

  6. Paleo-kinematics of ancient sedimentary sucessions: reading the rock record to disentangle autogenic and allogenic processes (Invited)

    Science.gov (United States)

    Gupta, S.; Paola, C.; Jordan, O.; Sixsmith, P.; Swenson, J. B.; Hampson, G.; Johnson, H.

    2009-12-01

    The sedimentary rock record is a mosaic of depositional units and surfaces that record migration and preservation of depositional and erosional geomorphic elements at geologic timescales. Interrogation of this archive of Earth surface dynamics has largely focussed on deriving the influence of allogenic forcing, with autogenic processes receiving little attention. Whilst much progress has recently been made in examining such interactions from experimental and numerical modelling studies, it has proved difficult to distinguish between such processes from field-based studies of stratigraphic successions. We submit that part of the problem lies in a lack of a rigorous framework with which to describe sedimentary architecture without recourse to model-driven descriptive toolkits. Sedimentary successions represent a record (though likely highly partial) of movements of geomorphic elements in space and time - thus stratigraphy really records the kinematics of net depositional landscapes at long timescales. We propose that depositional units and bounding surfaces can be interpreted as kinematic indicators - indicators of local change in the sedimentary system. Thus a coarsening-up shoreface facies succession is a kinematic indicator of shallowing (local) bathymetry. When such kinematic indicators are spatially and temporally interrogated we can begin to reconstruct the large-scale paleo-kinematics of a sedimentary system, and begin to address issues of allogenic and autogenic processes. In this talk, we describe some examples of reconstructing such paleo-kinematics using outstanding exposures of Cretaceous fluvial to shallow marine rock successions in New Mexico. We illustrate the types of depositional units and surfaces that can be used as paleo-kinematic indicators, and discuss their spatial scaling. We discuss the type of metrics that might usefully inform our understanding of autogenic and allogenic processes from the rock record.

  7. Zinc and germanium in the sedimentary rocks of Gale Crater on Mars indicate hydrothermal enrichment followed by diagenetic fractionation

    Science.gov (United States)

    Berger, Jeff A.; Schmidt, Mariek E.; Gellert, Ralf; Boyd, Nicholas I.; Desouza, Elstan D.; Flemming, Roberta L.; Izawa, Matthew R. M.; Ming, Douglas W.; Perrett, Glynis M.; Rampe, Elizabeth B.; Thompson, Lucy M.; VanBommel, Scott J. V.; Yen, Albert S.

    2017-08-01

    Zinc and germanium enrichments have been discovered in sedimentary rocks in Gale Crater, Mars, by the Alpha Particle X-ray Spectrometer on the rover Curiosity. Concentrations of Zn (910 ± 840 ppm) and Ge (65 ± 58 ppm) are tens to hundreds of times greater than in Martian meteorites and estimates for average silicate Mars. Enrichments occur in diverse rocks including minimally to extensively altered basaltic and alkalic sedimentary rocks. The magnitude of the enrichments indicates hydrothermal fluids, but Curiosity has not discovered unambiguous hydrothermal mineral assemblages. We propose that Zn- and Ge-rich hydrothermal deposits in the source region were dispersed in siliciclastic sediments during transport into the crater. Subsequent diagenetic mobilization and fractionation of Zn and Ge is evident in a Zn-rich sandstone (Windjana; Zn 4000 ppm, Ge 85 ppm) and associated Cl-rich vein (Stephen; Zn 8000 ppm, Ge 60 ppm), in Ge-rich veins (Garden City; Zn 2200 ppm, Ge 650 ppm), and in silica-rich alteration haloes leached of Zn (30-200 ppm). In moderately to highly altered silica-rich rocks, Ge remained immobile relative to leached elements (Fe, Mn, Mg, and Ca), consistent with fluid interaction at pH ≪ 7. In contrast, crosscutting Ge-rich veins at Garden City suggest aqueous mobilization as Ge-F complexes at pH Gale sediments and can aid in unraveling fluid histories as Curiosity's traverse continues.

  8. Paleomagnetics and Tectonic Significance of Cretaceous Sedimentary Rocks in the Mitchell Inlier, Blue Mountains, Oregon

    Science.gov (United States)

    Housen, B. A.; Dorsey, R. J.

    2001-12-01

    Recent mapping and synthesis of existing data from the western Idaho, western Nevada, and the Sierra Nevadas in California point to the existence of a large transpressional strike-slip fault zone along which outboard terranes were moved 100s of km in a dextral sense during Cretaceous time (Wyld and Wright, 2001). The Blue Mountains of eastern Oregon is a collage of terranes that lie immediately west of this proposed fault system, and contain Cretaceous strata that can be used to evaluate possible terrane translation. Albian to Cenomanian marine clastic sedimentary rocks of the Mitchell Inlier were derived from adjacent highlands during deformation and erosion of the composite Blue Mountains "superterrane". Recent structural and stratigraphic analysis of the Albian Hudspeth Formation in the Mitchell Inlier provides evidence for syn-depositional folding due to N-S contraction, which is attributed to transpression in a restraining bend along this strike-slip system (Lenegan and Dorsey, submitted ms.). To evaluate possible translation and rotation of the Blue Mountains, we conducted a paleomagnetic study of the Gable Creek Formation, a submarine-fan turbidite sequence that overlies the more complexly-deformed Main Mudstone Member of the Hudspeth Formation. A total of 120 samples from 18 sites in the Gable Creek Formation were thermally demagnetized. All samples displayed two components of remanence; the first-removed component unblocked between 80 and 300 C, while the second-removed component unblocked between 250 and 580 C. The age of the second-removed component is constrained to be mid-Cretaceous by: 1) a positive baked-contact test with an andesite dike of the Eocene Clarno Volcanics, 2) a positive conglomerate test in the Gable Creek Formation, and 3) a positive fold test. Using only site means with a95 North America Craton during mid-Cretaceous time, indicating a post-Albian clockwise rotation of 37.5 +/- 9.6 degrees and a poleward displacement of 1600 +/- 800 km

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

    Science.gov (United States)

    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.

  10. Chemostratigraphy of Late Cretaceous deltaic and marine sedimentary rocks from high northern palaeolatitudes in the Nuussuaq Basin, West Greenland

    DEFF Research Database (Denmark)

    Lenniger, Marc; Pedersen, Gunver Krarup; Bjerrum, Christian J.

    in the Late Cretaceous–Early Paleocene prior to the continental break-up and the beginning of sea-floor spreading in the Early Paleocene. The Nuussuaq Group comprises a more than 6 km thick succession of Cretaceous–Paleocene sedimentary rocks and includes the Atane Formation and the Itilli Formation, which...... consist of Late Cretaceous deposits from a major delta system and slope environment. The ongoing work will establish the chemostratigraphy in different depositional environments in the Nuussuaq Basin and investigate the palaeoceanography that prevailed during the Cenomanian–Turonian oceanic anoxic event...

  11. Chemical variations in Yellowknife Bay formation sedimentary rocks analyzed by ChemCam on board the Curiosity rover on Mars

    Science.gov (United States)

    Mangold, Nicolas; Forni, Olivier; Dromart, G.; Stack, K.M.; Wiens, Roger C.; Gasnault, Olivier; Sumner, Dawn Y.; Nachon, Marion; Meslin, Pierre-Yves; Anderson, Ryan B.; Barraclough, Bruce; Bell, J.F.; Berger, G.; Blaney, D.L.; Bridges, J.C.; Calef, F.; Clark, Brian R.; Clegg, Samuel M.; Cousin, Agnes; Edgar, L.; Edgett, Kenneth S.; Ehlmann, B.L.; Fabre, Cecile; Fisk, M.; Grotzinger, John P.; Gupta, S.C.; Herkenhoff, Kenneth E.; Hurowitz, J.A.; Johnson, J. R.; Kah, Linda C.; Lanza, Nina L.; Lasue, Jeremie; Le Mouélic, S.; Lewin, Eric; Malin, Michael; McLennan, Scott M.; Maurice, S.; Melikechi, Noureddine; Mezzacappa, Alissa; Milliken, Ralph E.; Newsome, H.L.; Ollila, A.; Rowland, Scott K.; Sautter, Violaine; Schmidt, M.E.; Schroder, S.; D'Uston, C.; Vaniman, Dave; Williams, R.A.

    2015-01-01

    The Yellowknife Bay formation represents a ~5 m thick stratigraphic section of lithified fluvial and lacustrine sediments analyzed by the Curiosity rover in Gale crater, Mars. Previous works have mainly focused on the mudstones that were drilled by the rover at two locations. The present study focuses on the sedimentary rocks stratigraphically above the mudstones by studying their chemical variations in parallel with rock textures. Results show that differences in composition correlate with textures and both manifest subtle but significant variations through the stratigraphic column. Though the chemistry of the sediments does not vary much in the lower part of the stratigraphy, the variations in alkali elements indicate variations in the source material and/or physical sorting, as shown by the identification of alkali feldspars. The sandstones contain similar relative proportions of hydrogen to the mudstones below, suggesting the presence of hydrous minerals that may have contributed to their cementation. Slight variations in magnesium correlate with changes in textures suggesting that diagenesis through cementation and dissolution modified the initial rock composition and texture simultaneously. The upper part of the stratigraphy (~1 m thick) displays rocks with different compositions suggesting a strong change in the depositional system. The presence of float rocks with similar compositions found along the rover traverse suggests that some of these outcrops extend further away in the nearby hummocky plains.

  12. Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2015-01-01

    In this study, equations are developed that predict for synthetic sedimentary rocks (clastics, carbonates and evapourates) thermal properties comprising thermal conductivity, specific heat capacity and thermal diffusivity. The rock groups are composed of mineral assemblages with variable contents...... of each property vary depending on the selected well-log combination. Best prediction is in the range of 2–8 per cent for the specific heat capacity, of 5–10 per cent for the thermal conductivity, and of 8–15 for the thermal diffusivity, respectively. Well-log derived thermal conductivity is validated...... by laboratory data measured on cores from deep boreholes of the Danish Basin, the North German Basin, and the Molasse Basin. Additional validation of thermal conductivity was performed by comparing predicted and measured temperature logs. The maximum deviation between these logs is conductivity...

  13. Modeling of laboratory experiments determining the chemico-osmotic, hydraulic and diffusion properties of sedimentary rocks

    Science.gov (United States)

    Takeda, M.; Hiratsuka, T.; Ito, K.

    2008-12-01

    -osmotic properties of clay-rich materials have been demonstrated in laboratory experiments. However, it remains inconclusive whether chemical osmosis can retain the pressure disequilibrium and so influence groundwater flow in a geologic time scale. Therefore, systematic research involving field-scale investigations of pressure and salinity distributions and experimental estimations of the chemico-osmotic, hydraulic and diffusive properties of formation media is required. This study focuses on the development of a laboratory experimental system and the analytical solutions to estimate the chemico-osmotic, hydraulic and diffusive properties of formation media. The experimental system consists of a flexible-wall permeameter cell that loads confining pressures, along with a closed fluid circuit to perform osmotic, hydraulic and diffusion experiments under background fluid pressures. This experimental design enables simulating underground conditions at the depths required for safety assessments of geological waste disposal. The effectiveness of the experimental system and the analytical solutions are demonstrated with a set of osmotic, hydraulic and diffusion experiments performed using sedimentary rocks.

  14. Subduction and accretion of sedimentary rocks in the Yakutat collision zone, St. Elias orogen, Gulf of Alaska

    Science.gov (United States)

    Van Avendonk, Harm J. A.; Gulick, Sean P. S.; Christeson, Gail L.; Worthington, Lindsay L.; Pavlis, Terry L.; Ridgway, Kenneth D.

    2013-11-01

    The collision of the Yakutat Block with the continental margin of North America in the Gulf of Alaska has intensified exhumation and erosion in the Chugach-St. Elias orogen over the last few million years. The resultant sediment flux and deposition of the glaciomarine Yakataga Formation on the continental shelf has filled a deep sedimentary basin offshore, where the Pamplona fold-thrust belt first deforms these strata. It is presently unclear whether the older sedimentary rocks of the Poul Creek and Kulthieth Formations are also accreted in the Pamplona Zone, or whether they are underthrusting the margin. In this paper we use marine seismic and well logging data to show that in the offshore Yakataga strata, porosity loss and lateral compaction can account for half of the convergence between the Yakutat Block and North America over the last 2 Myr. A lateral seismic velocity gradient in these syn-orogenic strata suggests that this layer-parallel shortening starts approximately 100 km outboard of the deformation front. Beneath the fold-and-thrust belt, where the seismic velocity is as high as 4.7 km/s, we image a large low-velocity zone (2.0-2.5 km/s) at 5 km depth. The dramatic decrease in seismic velocity with depth coincides with the boundary between the Yakataga and Poul Creek Formations in well data. Fine-grained and organic-rich Poul Creek strata possibly accommodate slip, such that older sedimentary rocks are entrained with the subducting Yakutat Block. Alternatively, the imaged low-velocity zone may have formed by increased fluid pressures in the hanging wall. In that case the décollement would lie beneath this low-velocity zone, possibly within the coal-bearing layers of the older and deeper Kulthieth Formation.

  15. Depositional environment and source rock potential of Cenomanian and Turonian sedimentary rocks of the Tarfaya Basin, Southwest Morocco

    Energy Technology Data Exchange (ETDEWEB)

    Ghassal, B.I.; Littke, R.; Sachse, V.; Sindern, S.; Schwarzbauer, J.

    2016-07-01

    Detailed organic and inorganic geochemical analyses were used to assess the depositional environment and source rock potential of the Cenomanian and Turonian oil shale deposits in the Tarfaya Basin. This study is based on core samples from the Tarfaya Sondage-4 well that penetrated over 300m of Mid Cretaceous organic matter-rich deposits. A total of 242 samples were analyzed for total organic and inorganic carbon and selected samples for total sulfur and major elements as well as for organic petrology, Rock-Eval pyrolysis, Curie-Point-pyrolysis-gaschromatography-Mass-Spectrometry and molecular geochemistry of solvent extracts. Based on major elements the lower Cenomanian differs from the other intervals by higher silicate and lower carbonate contents. Moreover, the molecular geochemistry suggests anoxic bottom marine water conditions during the Cenomanian-Turonian Boundary Event (CTBE; Oceanic Anoxic Event 2: OAE2). As a proxy for the Sorg/Corg ratio, the ratio total thiophenes/total benzenes compounds was calculated from pyrolysate compositions. The results suggest that Sorg/ Corg is low in the lower Cenomanian, moderate in the upper Cenomanian, very high in the CTBE (CenomanianTuronian Boundary Event) and high in the Turonian samples. Rock-Eval data reveal that the lower Cenomanian is a moderately organic carbon-rich source rock with good potential to generate oil and gas upon thermal maturation. On the other hand, the samples from the upper Cenomanian to Turonian exhibit higher organic carbon content and can be classified as oil-prone source rocks. Based on Tmax data, all rocks are thermally immature. The microscopic investigations suggest dominance of submicroscopic organic matter in all samples and different contents of bituminite and alginite. The lower Cenomanian samples have little visible organic matter and no bituminite. The upper Cenomanian and CTBE samples are poor in bituminite and have rare visible organic matter, whereas the Turonian samples change

  16. Evaluating Re-Os systematics in organic-rich sedimentary rocks in response to petroleum generation using hydrous pyrolysis experiments

    Science.gov (United States)

    Rooney, A.D.; Selby, D.; Lewan, M.D.; Lillis, P.G.; Houzay, J.-P.

    2012-01-01

    Successful application of the 187Re–187Os geochronometer has enabled the determination of accurate and precise depositional ages for organic-rich sedimentary rocks (ORS) as well as establishing timing constraints of petroleum generation. However, we do not fully understand the systematics and transfer behaviour of Re and Os between ORS and petroleum products (e.g., bitumen and oil). To more fully understand the behaviour of Re–Os systematics in both source rocks and petroleum products we apply hydrous pyrolysis to two immature hydrocarbon source rocks: the Permian Phosphoria Formation (TOC = 17.4%; Type II-S kerogen) and the Jurassic Staffin Formation (TOC = 2.5%; Type III kerogen). The laboratory-based hydrous pyrolysis experiments were carried out for 72 h at 250, 300, 325 and 350 °C. These experiments provided us with whole rock, extracted rock and bitumen and in some cases expelled oil and asphaltene for evaluation of Re–Os isotopic and elemental abundance. The data from these experiments demonstrate that the majority (>95%) of Re and Os are housed within extracted rock and that thermal maturation does not result in significant transfer of Re or Os from the extracted rock into organic phases. Based on existing thermodynamic data our findings suggest that organic chelating sites have a greater affinity for the quadravalent states of Re and Os than sulphides. Across the temperature range of the hydrous pyrolysis experiments both whole rock and extracted rock 187Re/188Os ratios show small variations (3.3% and 4.7%, for Staffin, respectively and 6.3% and 4.9% for Phosphoria, respectively). Similarly, the 187Os/188Os ratios show only minor variations for the Staffin and Phosphoria whole rock and extracted rock samples (0.6% and 1.4% and 1.3% and 2.2%). These isotopic data strongly suggest that crude oil generation through hydrous pyrolysis experiments does not disturb the Re–Os systematics in ORS as supported by various studies on natural systems. The

  17. The mineralogy and petrology of I-type cosmic spherules: Implications for their sources, origins and identification in sedimentary rocks

    Science.gov (United States)

    Genge, Matthew J.; Davies, Bridie; Suttle, Martin D.; van Ginneken, Matthias; Tomkins, Andrew G.

    2017-12-01

    I-type cosmic spherules are micrometeorites that formed by melting during atmospheric entry and consist mainly of iron oxides and FeNi metal. I-types are important because they can readily be recovered from sedimentary rocks allowing study of solar system events over geological time. We report the results of a study of the mineralogy and petrology of 88 I-type cosmic spherules recovered from Antarctica in order to evaluate how they formed and evolved during atmospheric entry, to constrain the nature of their precursors and to establish rigorous criteria by which they may be conclusively identified within sediments and sedimentary rocks. Two textural types of I-type cosmic spherule are recognised: (1) metal bead-bearing (MET) spherules dominated by Ni-poor (oxidation in the atmosphere. Precursors are suggested to be mainly kamacite and rare taenite grains. Vesicle formation within metal beads and extrusion of metallic liquid into surrounding wüstite grain boundaries suggests an evaporated iron sulphide or carbide component within at least 23% of particles. The Ni/Co ratios of metal vary from 14 to >100 and suggest that metal from H-group ordinary, CM, CR and iron meteorites may form the majority of particles. Oxidation during entry heating increases in the series MET oxidation during sub-solidus flight. The separation of metal beads due to deceleration is proposed to have been minor with most OX spherules shown to have been in equilibrium with metal beads containing >80 wt% Ni comprising a particle mass fraction of oxidation and cooling rate respectively. Variations in magnetite and wüstite crystal sizes are also suggested to relate to cooling rate allowing relative entry angle of particles to be evaluated. The formation of secondary metal in the form of sub-micron Ni-rich or Pt-group nuggets and as symplectite with magnetite was also identified and suggested to occur largely due to the exsolution of metallic alloys during decomposition of non-stoichiometric w

  18. Early trace of life from 3.95 Ga sedimentary rocks in Labrador, Canada

    Science.gov (United States)

    Tashiro, Takayuki; Ishida, Akizumi; Hori, Masako; Igisu, Motoko; Koike, Mizuho; Méjean, Pauline; Takahata, Naoto; Sano, Yuji; Komiya, Tsuyoshi

    2017-09-01

    The vestiges of life in Eoarchean rocks have the potential to elucidate the origin of life. However, gathering evidence from many terrains is not always possible, and biogenic graphite has thus far been found only in the 3.7–3.8 Ga (gigayears ago) Isua supracrustal belt. Here we present the total organic carbon contents and carbon isotope values of graphite (δ13Corg) and carbonate (δ13Ccarb) in the oldest metasedimentary rocks from northern Labrador. Some pelitic rocks have low δ13Corg values of ‑28.2, comparable to the lowest value in younger rocks. The consistency between crystallization temperatures of the graphite and metamorphic temperature of the host rocks establishes that the graphite does not originate from later contamination. A clear correlation between the δ13Corg values and metamorphic grade indicates that variations in the δ13Corg values are due to metamorphism, and that the pre-metamorphic value was lower than the minimum value. We concluded that the large fractionation between the δ13Ccarb and δ13Corg values, up to 25‰, indicates the oldest evidence of organisms greater than 3.95 Ga. The discovery of the biogenic graphite enables geochemical study of the biogenic materials themselves, and will provide insight into early life not only on Earth but also on other planets.

  19. Early trace of life from 3.95 Ga sedimentary rocks in Labrador, Canada.

    Science.gov (United States)

    Tashiro, Takayuki; Ishida, Akizumi; Hori, Masako; Igisu, Motoko; Koike, Mizuho; Méjean, Pauline; Takahata, Naoto; Sano, Yuji; Komiya, Tsuyoshi

    2017-09-27

    The vestiges of life in Eoarchean rocks have the potential to elucidate the origin of life. However, gathering evidence from many terrains is not always possible, and biogenic graphite has thus far been found only in the 3.7-3.8 Ga (gigayears ago) Isua supracrustal belt. Here we present the total organic carbon contents and carbon isotope values of graphite (δ 13 C org ) and carbonate (δ 13 C carb ) in the oldest metasedimentary rocks from northern Labrador. Some pelitic rocks have low δ 13 C org values of -28.2, comparable to the lowest value in younger rocks. The consistency between crystallization temperatures of the graphite and metamorphic temperature of the host rocks establishes that the graphite does not originate from later contamination. A clear correlation between the δ 13 C org values and metamorphic grade indicates that variations in the δ 13 C org values are due to metamorphism, and that the pre-metamorphic value was lower than the minimum value. We concluded that the large fractionation between the δ 13 C carb and δ 13 C org values, up to 25‰, indicates the oldest evidence of organisms greater than 3.95 Ga. The discovery of the biogenic graphite enables geochemical study of the biogenic materials themselves, and will provide insight into early life not only on Earth but also on other planets.

  20. Geochemical evaluation of Niger Delta sedimentary organic rocks: a new insight

    Science.gov (United States)

    Akinlua, Akinsehinwa; Torto, Nelson

    2010-05-01

    A geochemical evaluation of Niger Delta organic matter was carried out using supercritical fluid extraction (SFE) sample preparation procedure. Comparison of geochemical significance of gas chromatographic data of rock extracts of SFE with those of Soxhlet extraction method from previous studies was made in order to establish the usefulness of SFE in geochemical exploration. The assessment of geochemical character of the rock samples from the comparison and interpretation of other geochemical parameters were used to give more insights into understanding the source rocks characteristics of onshore and shelf portions of the Niger Delta Basin. The results of the gas chromatographic (GC) analysis of the rock extracts across the lithostratigraphic units show that Pr/Ph, Pr/nC17, Pr/nC18, CPI and odd/even preference ranged from 0.07 to 12.39, 0.04 to 6.66, 0.05 to 13.80, 0.12 to 8.4 and 0.06 to 8.12, respectively. The Rock-Eval pyrolysis data and geochemical ratios and parameters calculated from the GC data showed that most of the samples are mature and have strong terrestrial provenance while a few samples have strong marine provenance. The few marine source rocks are located in the deeper depth horizon. Pr/Ph and standard geochemical plots indicate that most of samples were derived from organic matter deposited in less reducing conditions, i.e. more of oxidizing conditions while a few samples have predominantly influence of reducing conditions. The results of trace metal analysis of older samples from Agbada Formation also indicate marine and mixed organic matter input deposited in less reducing conditions. The results obtained in this study are comparable with those obtained from previous studies when Soxhlet extraction method was used and also indicated the presence of more than one petroleum systems in the Niger Delta.

  1. Frequency-Based Precursory Acoustic Emission Failure Sequences In Sedimentary And Igneous Rocks Under Uniaxial Compression

    Science.gov (United States)

    Colin, C.; Anderson, R. C.; Chasek, M. D.; Peters, G. H.; Carey, E. M.

    2016-12-01

    Identifiable precursors to rock failure have been a long pursued and infrequently encountered phenomena in rock mechanics and acoustic emission studies. Since acoustic emissions in compressed rocks were found to follow the Gutenberg-Richter law, failure-prediction strategies based on temporal changes in b-value have been recurrent. In this study, we extend on the results of Ohnaka and Mogi [Journal of Geophysical Research, Vol. 87, No. B5, p. 3873-3884, (1982)], where the bulk frequency characteristics of rocks under incremental uniaxial compression were observed in relation to changes in b-value before and after failure. Based on the proposition that the number of low-frequency acoustic emissions is proportional to the number of high-amplitude acoustic emissions in compressed rocks, Ohnaka and Mogi (1982) demonstrated that b-value changes in granite and andesite cores under incremental uniaxial compression could be expressed in terms of the percent abundance of low-frequency events. In this study, we attempt to demonstrate that the results of Ohnaka and Mogi (1982) hold true for different rock types (basalt, sandstone, and limestone) and different sample geometries (rectangular prisms). In order to do so, the design of the compression tests was kept similar to that of Ohnaka and Mogi (1982). Two high frequency piezoelectric transducers of 1 MHz and a 500 kHz coupled to the sides of the samples detected higher and lower frequency acoustic emission signals. However, rather than gathering parametric data from an analog signal using a counter as per Ohnaka and Mogi (1982), we used an oscilloscope as an analog to digital converter interfacing with LabVIEW 2015 to record the complete waveforms. The digitally stored waveforms were then processed, detecting acoustic emission events using a statistical method, and filtered using a 2nd order Butterworth filter. In addition to calculating the percent abundance of low-frequency events over time, the peak frequency of the

  2. Discrimination between sedimentary rocks from close-range visible and very-near-infrared images

    NARCIS (Netherlands)

    Pozo, Susana Del; Lindenbergh, R.C.; Rodríguez-Gonzálvez, Pablo; Blom, J.C.; González-Aguilera, Diego

    2015-01-01

    Variation in the mineral composition of rocks results in a change of their spectral response capable of being studied by imaging spectroscopy. This paper proposes the use of a low-cost handy sensor, a calibrated visible-very near infrared (VIS-VNIR) multispectral camera for the recognition of

  3. Upper Jurassic to Lower Cretaceous(?) synorogenic sedimentary rocks in the southern Spring Mountains, Nevada

    Science.gov (United States)

    Carr, Michael D.

    1980-08-01

    A newly recognized sequence of Upper Jurassic to Lower Cretaceous(?) terrigenous rocks in the Good-springs district, Nevada, was deposited during the emplacement of the Contact thrust plate. Two facies are recognized: (1) interbedded conglomerate and sandstone derived from Mesozoic igneous and terrigenous platform rocks and (2) interbedded carbonate and sandstone-clast conglomerate, quartz sandstone, and red shale. No igneous detritus occurs in the facies with carbonate-clast conglomerate. Carbonate clasts could only have been derived from the Paleozoic carbonate sequence, which was exposed in the area by latest Jurassic to earliest Cretaceous thrusting. The age of rocks from a volcanic unit within the synorogenic sequence was determined radiometrically to be 150 ± 10 m.y. (K-Ar on biotite). The sequence was deposited disconformably on deeply eroded rocks of the early Mesozoic platform and ultimately overridden from the west by the Contact thrust plate. Information from the sequence corroborates previously reported regional data regarding the timing and nature of the Contact-Red Springs thrust event. *Present address: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025

  4. Numerical analysis of nuclear magnetic resonance relaxation-diffusion responses of sedimentary rock

    Energy Technology Data Exchange (ETDEWEB)

    Arns, Christoph H; AlGhamdi, Tariq; Arns, Ji-Youn, E-mail: c.arns@unsw.edu.au [School of Petroleum Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2011-01-15

    The nuclear magnetic resonance (NMR) relaxation-diffusion response of porous reservoir rock is frequently used, e.g. in oil field applications, to extract characteristic length scales of pore space or information about saturating fluids. External gradients are typically applied to encode for diffusion. In reservoir rocks, field inhomogeneities due to internal gradients can even at low fields be strong enough to interfere with this encoding. Furthermore, the encoding for diffusion coefficients of fluids takes a finite amount of time, during which diffusing fluid molecules can experience restricted diffusion. Both effects can combine to make the interpretation of the diffusion dimension of a relaxation-diffusion measurement difficult. We use x-ray-CT images of porous rock samples to define the solid and fluid phases of reservoir rock and simulate the full experimental pulse sequence, taking into account the static applied field, external gradients and internal gradients as a function of susceptibility of each component, and surface and bulk relaxation properties of fluids and fluid-fluid and fluid-solid interfaces. We carry out simulations of NMR relaxation-diffusion measurements, while explicitly tracking the time-dependent diffusion coefficient in each fluid as well as associated local gradients. This allows us to quantify the influence of restricted diffusion and internal gradients for common choices of experimental parameters.

  5. Provenance analysis of Roman stone artefacts from sedimentary rocks from the archaeological site near Mošnje, NW Slovenia

    Directory of Open Access Journals (Sweden)

    Snježana Miletić

    2016-08-01

    Full Text Available This study deals with the macroscopic and microfacies characterisation of Roman stone artefacts excavated in 2006 from a Roman villa rustica near Mošnje (NW Slovenia with the aim of defiing their provenance. A total of 28 representative fids (querns, mortars, whetstones, tooled and rounded stones, a fragment of stone slab, mosaic tesserae and two architectural elements - one with a relief made of clastic and carbonate sedimentary rocks were examined. Comparison was made with rock samples taken from quarries and gravel bars close to the archaeological site, as well as from larger distance to the site. The majority of artefact sampled is composed of Upper Palaeozoic quartz sandstones, which are found as pebbles in gravel bars close to the archaeological site; while 2 samples were from Quaternary coarse grained clastic rocks which can be found in local glacio-flvial sediments. Other fids were made of four different Mesozoic shallow-water limestones which outcrop in different areas of Central and SW Slovenia. The nearest Lower Jurassic biopelmicritic limestones are found at the western periphery of Ljubljana in Podutik. Cretaceous miliolid limestones and biocalcarenitic limestones with rudists are common in the successions of the Dinaric Carbonate Platform in SW Slovenia (for example, on the Trieste-Komen Plateau, NE Italy and SW Croatia. This indicates that the limestones for architectural elements, stone mortars and tesserae were brought to Mošnje from distant locations. Smaller stone tools are likely to have been made at the location of the archaeological site from material gathered locally, mostly pebbles from clastic rocks, which were accessible and suitable for tooling.

  6. Testing corrections for paleomagnetic inclination error in sedimentary rocks: A comparative approach

    Science.gov (United States)

    Tauxe, Lisa; Kodama, Kenneth P.; Kent, Dennis V.

    2008-08-01

    Paleomagnetic inclinations in sedimentary formations are frequently suspected of being too shallow. Recognition and correction of shallow bias is therefore critical for paleogeographical reconstructions. This paper tests the reliability of the elongation/inclination ( E/ I) correction method in several ways. First we consider the E/ I trends predicted by various PSV models. We explored the role of sample size on the reliability of the E/ I estimates and found that for data sets smaller than ˜100-150, the results were less reliable. The Giant Gaussian Process-type paleosecular variation models were all constrained by paleomagnetic data from lava flows of the last five million years. Therefore, to test whether the method can be used in more ancient times, we compare model predictions of E/ I trends with observations from five Large Igneous Provinces since the early Cretaceous (Yemen, Kerguelen, Faroe Islands, Deccan and Paraná basalts). All data are consistent at the 95% level of confidence with the E/ I trends predicted by the paleosecular variation models. The Paraná data set also illustrated the effect of unrecognized tilting and combining data over a large latitudinal spread on the E/ I estimates underscoring the necessity of adhering to the two principle assumptions of the method. Then we discuss the geological implications of various applications of the E/ I method. In general the E/ I corrected data are more consistent with data from contemporaneous lavas, with predictions from the well constrained synthetic apparent polar wander paths, and other geological constraints. Finally, we compare the E/ I corrections with corrections from an entirely different method of inclination correction: the anisotropy of remanence method of Jackson et al. [Jackson, M.J., Banerjee, S.K., Marvin, J.A., Lu, R., Gruber, W., 1991. Detrital remanence, inclination errors and anhysteretic remanence anisotropy: quantitative model and experimental results. Geophys. J. Int. 104, 95

  7. Testing correction for paleomagnetic inclination error in sedimentary rocks: a comparative approach

    Science.gov (United States)

    Tauxe, L.; Kodama, K. P.; Kent, D. V.

    2008-05-01

    Paleomagnetic inclinations in sedimentary formations are frequently suspected of being too shallow. Recognition and correction of shallow bias is therefore critical for paleogeographical reconstructions. The elongation/inclination (E/I) correction method of Tauxe and Kent (2004) relies on the twin assumptions that inclination flattening follows the empirical sedimentary flattening formula and that the distribution of paleomagnetic directions can be predicted from a paleosecular variation (PSV) model. We will test the reliability of the E/I correction method in several ways. First we consider the E/I trends predicted by various PSV models. The Giant Gaussian Process-type paleosecular variation models were all constrained by paleomagnetic data from lava flows of the last five million years. Therefore, to test whether the method can be used in more ancient times, we will compare model predictions of E/I trends with observations from four Large Igneous Provinces since the Jurassic (Yemen, Kerguelen, Faroe Islands, and Deccan basalts). All data are consistent at the 95% level of confidence with the elongation/inclination trends predicted by the paleosecular variation models. Then we will then discuss the geological implications of various applications of the E/I method. In general the E/I corrected data are more consistent with data from contemporaneous lavas, with predictions from the well constrained synthetic apparent polar wander paths, and other geological constraints. Finally, we will compare the E/I corrections with corrections from an entirely different method of inclination correction: the anisotropy of remanence method of Jackson et al. (1991) which relies on measurement of remanence and particle anisotropies of the sediments. In the two cases where a direct comparison can be made, the two methods give corrections that are consistent within error. In summary, it appears that the elongation/inclination method for recognizing and corrected the effects of

  8. Estimation Of The Mining Damage Risk In The Hypothetical Impact Area Of The Concurrent Processes Of Rock Mass Disorders

    Science.gov (United States)

    Piwowarski, Wiesław; Isakow, Zbigniew; Juzwa, Jacek

    2015-12-01

    The aim of this work is the estimation of the risk of mining damage occurrence, based on uncertain information regarding the impact of the concurrent processes of deformation and vibration. This problem concerns the experimental and theoretical description of the so-called critical phenomena occurring during the reaction mining area ↔ building object. Post-mining deformations of the rock mass medium and paraseismic vibrations can appear at a considerable distance from the sub-area of the mining operation - hence, the determination of the measures of their impacts is usually somewhat subjective, while the estimation of the mining damage based on deterministic methods is often insufficient. It is difficult to show the correlation between the local maximum of the impact of the velocity vector amplitude and the damage to the building - especially if the measures of interaction are not additive. The parameters of these impacts, as registered by measurements, form finite sets with a highly random character. Formally, it is adequate to the mapping from the probability space to the power set. For the purposes of the present study, the Dempster - Shafer model was used, where space is characterised by subadditive and superadditive measures. Regarding the application layer, the conclusions from the expert evaluations are assumed to be the values of random variables. The model was defined, and the risk of damage occurrence was estimated.

  9. Raman spectroscopy of carbon and solid bitumens in sedimentary and metamorphic rocks

    Science.gov (United States)

    Jehlička, Jan; Urban, Ondřej; Pokorný, Jan

    2003-08-01

    Different types of carbonaceous matter from rocks display Raman spectral features which knowledge permits to obtain structural information of these materials. Application of Raman microspectroscopy to investigate kerogen, bitumen, fossils, highly carbonified amorphous carbon as well as graphite from different environments is reviewed. Differences in Raman spectra and structural differences between carbonaceous samples differing in their metamorphic history are discussed on the basis of new data.

  10. Potassium metasomatism of volcanic and sedimentary rocks in rift basins, calderas and detachment terranes

    Science.gov (United States)

    Chapin, C. E.; Lindley, J. I.

    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 basins.

  11. Geochemical characteristics of the Permian sedimentary rocks from Qiangtang Basin: Constraints for paleoenvironment and paleoclimate

    Directory of Open Access Journals (Sweden)

    Junjie Hu

    2017-01-01

    Full Text Available Qiangtang Basin is expected to become important strategic petroleum exploitation area in China. However, little research has been done on the Permian strata in this area. This paper presents Lower Permian Zhanjin Formation geochemical data from the Jiaomuri area, reconstructing the paleo-depositional environment and providing information for further petroleum exploration. The geochemical characteristics of 19 samples were investigated. These geochemical samples show a developed mud flat characteristic with light rich clay content. The geological data were used to constrain the paleoredox environment, which proved that these sediments were deposited mainly beneath a slightly oxic water column with relatively low paleoproductivity as evidenced by the P/Ti (mean of 0.07 and Ba/Al (mean of 20.5. Palaeoclimate indexes such as the C-value (0.24-1.75 and Sr/Cu (1.28-11.58 reveal a humid climatic condition during Zhanjin Formation sediment deposition. The ω(LaN/ω(YbN ratio values indicate a fast sedimentary rate during the deposition period.

  12. Disintegration of sedimentary rocks used as building material: evaluation and quantification in 4D

    Science.gov (United States)

    Dewanckele, J.; Boone, M. A.; de Kock, T.; Cnudde, V.; Boone, M. N.; de Witte, Y.; Pieters, K.; van Loo, D.; van Hoorebeke, L.; Jacobs, P.

    2009-04-01

    Many natural building stones are subject to weathering processes that may lead to their disintegration. When rocks are exposed to extreme exogenous factors such as a combination of water and freeze-thaw cycles, they can deteriorate and cause problems concerning the maintenance of the structure. Some rock types are more susceptible to weathering processes than others, in which fluctuating environmental factors as well as the position of the stone in the building and the endogenous or geological parameters of the stone itself play an important role. In order to determine the influencing geological parameters (pore structure and interconnectivity, mineralogy, cementation…) several techniques are available. One of the techniques mainly focused on in this study is X-ray computed tomography (CT). This rapid and easy-to-use method enables to visualize internal rock structures in a non-destructive way and without any sample preparation. The obtained and afterwards processed digital information enables a better understanding in the 3D geometric rock properties. To obtain a CT-scan of the stone, the sample rotates 360˚ while digital radiographs are taken. In this study 800 radiographs were reconstructed (using the Octopus software package) to create virtual cross-sections through the object. Although X-ray CT is a very valuable technique for 3D reconstruction, the single radiographs also contain a lot of information. They can e.g. be used to measure the contact angle of a drop of water and thus be compared to traditional optical contact angle measurement systems. As the sample stays fixed on the rotational stage of the CT-scanner, a drop of water is released onto the stone's surface. Capillary processes change the drop shape changes during time. After the subtraction of the initial dry state from the wet state, the contact angle of the water drop can be calculated. The advantage of this approach is that also the impregnation depth of the water inside the stone can

  13. Effect of confining pressure on diffusion coefficients in clay-rich, low-permeability sedimentary rocks.

    Science.gov (United States)

    Xiang, Y; Al, T; Mazurek, M

    2016-12-01

    The effect of confining pressure (CP) on the diffusion of tritiated-water (HTO) and iodide (I(-)) tracers through Ordovician rocks from the Michigan Basin, southwestern Ontario, Canada, and Opalinus Clay from Schlattingen, Switzerland was investigated in laboratory experiments. Four samples representing different formations and lithologies in the Michigan Basin were studied: Queenston Formation shale, Georgian Bay Formation shale, Cobourg Formation limestone and Cobourg Formation argillaceous limestone. Estimated in situ vertical stresses at the depths from which the samples were retrieved range from 12.0 to 17.4MPa (Michigan Basin) and from 21 to 23MPa (Opalinus Clay). Effective diffusion coefficients (De) were determined in through-diffusion experiments. With HTO tracer, applying CP resulted in decreases in De of 12.5% for the Queenston Formation shale (CPmax=12MPa), 30% for the Georgian Bay Formation shale (15MPa), 34% for the Cobourg Formation limestone (17.4MPa), 31% for the Cobourg Formation argillaceous limestone (17.4MPa) and 43-46% for the Opalinus Clay (15MPa). Decreases in De were larger for the I(-) tracer: 13.8% for the Queenston shale, 42% for the Georgian Bay shale, 50% for the Cobourg Formation limestone, 55% for the Cobourg Formation argillaceous limestone and 63-68% for the Opalinus Clay. The tracer-specific nature of the response is attributed to an increasing influence of anion exclusion as the pore size decreases at higher CP. Results from the shales (including Opalinus Clay) indicate that the pressure effect on De can be represented by a linear relationship between De and ln(CP), which provides valuable predictive capability. The nonlinearity results in a relatively small change in De at high CP, suggesting that it is not necessary to apply the exact in situ pressure conditions in order to obtain a good estimate of the in situ diffusion coefficient. Most importantly, the CP effect on shale is reversible (±12%) suggesting that, for

  14. New paleomagnetic data from late Paleozoic sedimentary rocks of Novaya Zemlya Archipelago: tectonic implications

    Science.gov (United States)

    Abashev, Victor V.; Metelkin, Dmitry V.; Mikhaltsov, Nikolay E.; Vernikovsky, Valery A.; Matushkin, Nikolay Yu.

    2017-04-01

    New paleomagnetic data for Novaya Zemlya archipelago were obtained by processing the samples collection gathered during the 2014 field season. The paleomagnetic directions and paleomagnetic poles were determined from the Paleozoic sedimentary complexes located on the Southern Island (Upper Permian) and the Northern Island (Lower and Upper Devonian, Upper Carboniferous) of the archipelago. Positive fold and reversal tests indicate that the isolated paleomagnetic directions correspond to the primary magnetization components. The corresponding paleomagnetic pole are in good agreement with poles obtained earlier in the 1980s by E.L. Gurevich and I.A. Pogarskaya. Considering the confidence ovals, the paleomagnetic poles obtained for the sites of the Northern Island are located close to the corresponding path segment of the APWP of Europe. This means that at least since the early Devonian, the northern part of Novaya Zemlya Archipelago had a position that was close to its current position relatively to the Arctic margin of Europe and has not undergone significant shifts or rotations. However, the upper Permian paleomagnetic pole for the Southern Island is very different from the corresponding part of the European APWP. We are considering this pole position within a model, involving significant intraplate movement between the structures of the European and Siberian tectonic provinces until the Late Cretaceous. The sinistral strike-slips inferred by the model could have caused or were accompanying the opening of the Mesozoic rift system in Western Siberia. This event has reached its maximum within the South Kara basin and resulted in the north-westward (in geographic coordinates) displacement of the southern part of the Novaya Zemlya Archipelago in relation to the Arctic margin of Europe and in the deformation of the Pay-Khoy-Novaya Zemlya margin, which caused its modern curved form. The study was supported by the Russian Science Foundation, grant No. 14-37-00030 and the

  15. Using geochemistry to establish the igneous provenances of the Neogene continental sedimentary rocks in the Central Depression and Altiplano, Central Andes

    Science.gov (United States)

    Pinto, Luisa; Hérail, Gérard; Moine, Bernard; Fontan, François; Charrier, Reynaldo; Dupré, Bernard

    2004-04-01

    Geochemical and mineralogical data from ancient sedimentary strata can be reliable indicators of the provenance of sediments. The heavy mineral assemblages and the major and trace element contents of sedimentary rocks from the Neogene continental successions of the Central Depression in Chile and the Mauri and Corque Basins in the Altiplano of Bolivia reflect volcanic source rocks with different degrees of magmatic differentiation and alkalinity. These results indicate that the source rocks of the Central Depression were less differentiated (andesite to rhyodacite) than those of the Altiplano basins (rhyodacite to rhyolite). The low concentration (cations per formula unit) of total Al (alkaline source rock. By contrast, the high concentration of total Al (>0.15 pfu) and [Ca+Na] (˜0.92 pfu), the variable Ti content (0.01-0.04 pfu) of the clinopyroxenes and the high [Nb/Y] (>0.7) in whole-rock analyses of sandstones from the Mauri Basin indicate erosion of alkaline rock sources. Locally, the low concentration of total Al (<0.15 pfu) in the detrital clinopyroxenes of sandstones from the Corque Basin indicates erosion of a subalkaline source rock. The chemical trends in the sandstones are similar to those in volcanic suites from the Western Cordillera and Eastern Cordillera of the Central Andes.

  16. Geochemical Characterization of Trace MVT Mineralization in Paleozoic Sedimentary Rocks of Northeastern Wisconsin, USA

    Directory of Open Access Journals (Sweden)

    John A. Luczaj

    2016-06-01

    Full Text Available Disseminated Mississippi Valley-type (MVT mineralization occurs throughout northeastern Wisconsin, USA, and is recognized as the source of regionally extensive natural groundwater contamination in the form of dissolved arsenic, nickel, and other related metals. Although considerable attention has been given to arsenic contamination of groundwater in the region, limited attention has been focused on characterizing the bedrock sources of these and other metals. A better understanding of the potential sources of groundwater contamination is needed, especially in areas where groundwater is the dominant source of drinking water. This article describes the regional, stratigraphic, and petrographic distribution of MVT mineralization in Paleozoic rocks of northeastern Wisconsin, with a focus on sulfide minerals. Whole-rock geochemical analysis performed on 310 samples of dolomite, sandstone, and shale show detectable levels of arsenic, nickel, cobalt, copper, lead, zinc, and other metals related to various sulfide mineral phases identified using scanning electron microscopy. MVT minerals include pyrite, marcasite, sphalerite, galena, chalcopyrite, fluorite, celestine, barite, and others. We describe the first nickel- and cobalt-bearing sulfide mineral phases known from Paleozoic strata in the region. Arsenic, nickel, and cobalt are sometimes present as isomorphous substitutions in pyrite and marcasite, but discrete mineral phases containing nickel and cobalt elements are also observed, including bravoite and vaesite. Locally abundant stratigraphic zones of sulfide minerals occur across the region, especially in the highly enriched Sulfide Cement Horizon at the top of the Ordovician St. Peter Sandstone. Abundant quantities of sulfides also appear near the contact between the Silurian Mayville Formation and the underlying Maquoketa and Neda formations in certain areas along and east of the Niagara escarpment. This article illustrates how a detailed

  17. Deformation of Sedimentary Rock Across the San Andreas Fault Zone: Mesoscale and Microscale Structures Displayed in Core From SAFOD

    Science.gov (United States)

    Chester, J. S.; Chester, F. M.; Kirschner, D. L.; Almeida, R.; Evans, J. P.; Guillemette, R. N.; Hickman, S.; Zoback, M.; Ellsworth, W.

    2007-12-01

    Sedimentary rocks captured in cores taken at the San Andreas Fault Observatory at Depth (SAFOD) provide an unparalleled sampling of deformation in the transition zone between creeping and locked segments of a major transform fault at 2.5-3.1 km vertical depth. These samples provide the unique opportunity to study deformation processes and the development of brittle structures within porous and granular rocks that have been subjected to variable loading rates and chemically reactive fluids while residing at the top of the seismogenic zone. The samples provide a transect from relatively undeformed host rock through highly fractured and sheared rock, and capture the two prominent zones of active, aseismic slip. Core recovery was almost complete. Wrap-around 1:1 map tracings of the outer surfaces of all cores characterize the lithology and mesoscale deformation. Cores from 3056-3067 m and 3141-3153 m measured depth (MD) sample moderately deformed rock at the western boundary of the fault zone. The cores display massive to finely laminated, pebbly arkosic sandstones with lesser amounts of fine-grained sandstone and siltstone. Numerous shear fractures and cm-thick cataclastic shear zones form a conjugate geometry indicating contraction at high angles to the San Andreas fault. Both intervals display minor faults that juxtapose different lithologies consistent with meters or greater of slip. Fracture density is variable but tends to increase with proximity to the minor faults. Cross-cutting relationships between shear fractures and cataclastic zones indicate a general progression from early faulting along thicker shear zones to later, more localized slip within shear zones and along fractures. Microstructures provide ample evidence for densification of the sandstones through grain-scale fracture and crushing, as well as fluid assisted processes of crack-sealing, dissolution-precipitation, and alteration-neocrystallization. Grain-scale features are consistent with these

  18. Analysis of hydromechanical well tests in fractured sedimentary rock at the NAWC site, New Jersey

    Science.gov (United States)

    Murdoch, L.C.; Hisz, D.B.; Ebenhack, J.F.; Fowler, D.E.; Tiedeman, C.R.; Germanovich, L.N.

    2009-01-01

    Hydromechanical well tests involve measuring and interpreting displacements along with hydraulic heads that result when a hydraulic stress is applied to a well. The motivation behind this type of test is that the displacement measurements provide information about the constitutive properties and structure of the aquifer that go beyond what can be derived from pressure signals alone. We used a borehole extensometer to measure transient displacements with a resolution of +/- 25 nm during well tests in fractured mudstone and sandstone at the former Naval Air Warfare Center in West Trenton, New Jersey. One well showed opening displacements on the order of 300nm during slug tests with maximum head changes of 7 m. Inversion of the transient signals suggest that a conductive fracture (aperture = 380 ??m, normal stiffness = 8??10 8 Pa/m) was largely responsible for the pressure signal, but the displacement signal appears to have resulted from both the fracture and deformation of the enveloping sandstone (E = 5 GPa, permeability = 0.6 md). At another well, an anomalous but repeatable signal was characterized by closing displacements during increasing pressure. This displacement signal can be explained by a hydraulically active fracture below the extensometer that became pressurized and compressed the overly sediments. Poroelastic theoretical analyses were inverted to estimate parameters and verify interpretations. Copyright 2009 ARMA, American Rock Mechanics Association.

  19. The sedimentary organic matter from a Lake Ichkeul core (far northern Tunisia): Rock-Eval and biomarker approach

    Science.gov (United States)

    Affouri, Hassène; Sahraoui, Olfa

    2017-05-01

    The vertical distributions of bulk and molecular biomarker composition in samples from a ca. 156 cm sediment core from Lake Ichkeul were determined. Bulk analysis (Rock-Eval pyrolysis, carbonate, lipid extraction) and molecular analysis of saturated fractions were used to characterize the nature, preservation conditions and input of sedimentary organic matter (OM) to this sub-wet lake environment. The sediments are represented mainly by gray-black silty-clay facies where the carbonate (CaCO3) content varies in a range of 10-30% dry sediment. Rock-Eval pyrolysis revealed a homogeneous total organic carbon (TOC) content of ca. 1% sediment, but with down core fluctuation, indicating different anoxic conditions at different depths and material source variation. The values show three periods of relative enrichment, exceeding ca. 1%, at 146-134 cm, 82 cm and 14-0 cm depth. The low Hydrogen Index (HI) values [<119 mg hydrocarbon (HC)/g TOC)] were characteristic of continental Type III OM. The Tmax values in the range 415-420 °C were characteristic of immature OM at an early diagenetic stage. The distributions of n-alkanes (C17 to C34), isoprenoid (iso) alkanes (pristane and phytane), terpanes and steranes showed that the OM is a mixture of marine algal and bacterial source and emergent and floating higher plant origin. In addition, the distributions, as well as several biomarker ratios (n-alkanes, iso-alkanes/n-alkanes), showed that the OM is a mixture of immature and mature. Significant downcore fluctuation was observed in the molecular composition. This indicates intense microbial activity below ca. 50 cm core depth under an anoxic and brackish environment.

  20. Mineralogical and geochemical characteristics of Miocene pelitic sedimentary rocks from the south-western part of the Pannonian Basin System (Croatia: Implications for provenance studies

    Directory of Open Access Journals (Sweden)

    Anita Grizelj

    2017-01-01

    Full Text Available Fifty-two samples of Miocene pelitic sedimentary rock from outcrops on Medvednica, Moslavačka Gora and Psunj Mts., and boreholes in the Sava Depression and the Požega Sub-depression were investigated. These sediments formed in different marine (with normal and reduced salinity, brackish, and freshwater environments, depending on the development stage of the Pannonian Basin System. Carbonate minerals, clay minerals and quartz are the main constituents of all pelitic sedimentary rocks, except in those from Moslavačka Gora Mt in which carbonate minerals are not present. Feldspars, pyrite, opal-CT, and hematite are present as minor constituents in some rocks. Besides calcite, dependent on the sedimentary environment and diagenetic changes, high-magnesium calcite, aragonite, dolomite and ankerite/Ca-dolomite are also present. Smectite or illite-smectite is the main clay minerals in the samples. Minor constituents, present in almost all samples, are detrital illite and kaolinite. In some samples chlorite is also present in a low amount. Major elements, trace elements and rare earth elements patterns used in provenance analysis show that all analysed samples have a composition similar to the values of the upper continental crust (UCC. The contents of major and trace elements as well as SiO2/Al2O3, K2O/Al2O3, Na2O/K2O, Eu/Eu*, La/Sc, Th/Sc, La/Co Th/Co, Th/Cr, Ce/Ce* and LREE/HREE ratios, show that the analysed pelitic sedimentary rocks were formed by weathering of different types of mostly acidic (silicic, i.e. felsic rocks.

  1. Effect of mineral constituents in the bioleaching of uranium from uraniferous sedimentary rock samples, Southwestern Sinai, Egypt.

    Science.gov (United States)

    Amin, Maisa M; Elaassy, Ibrahim E; El-Feky, Mohamed G; Sallam, Abdel Sattar M; Talaat, Mona S; Kawady, Nilly A

    2014-08-01

    Bioleaching, like Biotechnology uses microorganisms to extract metals from their ore materials, whereas microbial activity has an appreciable effect on the dissolution of toxic metals and radionuclides. Bioleaching of uranium was carried out with isolated fungi from uraniferous sedimentary rocks from Southwestern Sinai, Egypt. Eight fungal species were isolated from different grades of uraniferous samples. The bio-dissolution experiments showed that Aspergillus niger and Aspergillus terreus exhibited the highest leaching efficiencies of uranium from the studied samples. Through monitoring the bio-dissolution process, the uranium grade and mineralogic constituents of the ore material proved to play an important role in the bioleaching process. The tested samples asserted that the optimum conditions of uranium leaching are: 7 days incubation time, 3% pulp density, 30 °C incubation temperature and pH 3. Both fungi produced the organic acids, namely; oxalic, acetic, citric, formic, malonic, galic and ascorbic in the culture filtrate, indicating an important role in the bioleaching processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Geological and geochemical characteristics of sedimentary rocks in Kremna, basin (Serbia)

    Science.gov (United States)

    Perunović, Tamara; Jovančićević, Branimir; Brčeski, Ilija; Šajnović, Aleksandra; Stojanović, Ksenija; Simić, Vlada; Kašanin-Grubin, Milica

    2014-05-01

    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 basins spanning in age from Oligocene to Lower Pliocene. The aim of this study was to examine Lower Miocene Kremna basin, located in southwest Serbia. Kremna basin is a small basin, 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 basin. 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 basin: 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 basin. 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

  3. Natural Radioactivity of Intrusive-Metamorphic and Sedimentary Rocks of the Balkan Mountain Range (Serbia, Stara Planina

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    Sanna Masod Abdulqader

    2017-12-01

    Full Text Available Stara Planina (also known as the Balkan mountain range is known for numerous occurrences and deposits of uranium and associated radionuclides. It is also famous for its geodiversity. The geologic framework is highly complex. The mountain is situated between the latitudes of 43° and 44° N and the longitudes from 22°16′ to 23°00′ E. Uranium exploration and radioactivity testing on Stara Planina began back in 1948. Uranium has also been mined in the zone of Kalna, within the Janja granite intrusive. The naturally radioactive geologic units of Stara Planina are presented in detail in this paper. The main sources of radioactivity on Stara Planina can be classified as: 1. Granitic endogenous—syngenetic–epigenetic deposits and occurrences; 2. Metamorphogenic—syngenetic; and 3. Sedimentary, including occurrences of uranium deposition and fluctuation caused by water in different types of sedimentary rocks formed in a continental setting, which could be classified under epigenetic types. The area of Stara Planina with increased radioactivity (higher than 200 cps, measured by airborne gamma spectrometry, is about 380 square kilometers. The highest values of measured radioactivity and uranium grade were obtained from a sample taken from the Mezdreja uranium mine tailing dump, where 226Ra measures 2600 ± 100 Bq/kg and the uranium grade is from 76.54 to 77.65 ppm U. The highest uranium (and lead concentration, among all samples, is measured in graphitic schist with high concentrations of organic (graphitic material from the Inovska Series—99.47 ppm U and 107.69 ppm Pb. Thorium related radioactivity is the highest in granite samples from the Janja granite in the vicinity of the Mezdreja granite mine and the Gabrovnica granite mine tailing dump, and it is the same—250 ± 10 Bq/kg for 232Th, while the thorium grade varies from 30.82 to 60.27 ppm Th. In gray siltstones with a small amount of organic material, the highest radioactivity is

  4. Mars sedimentary rock erosion rates constrained using crater counts, with applications to organic-matter preservation and to the global dust cycle

    Science.gov (United States)

    Kite, Edwin S.; Mayer, David P.

    2017-04-01

    Small-crater counts on Mars light-toned sedimentary rock are often inconsistent with any isochron; these data are usually plotted then ignored. We show (using an 18-HiRISE-image, > 104-crater dataset) that these non-isochron crater counts are often well-fit by a model where crater production is balanced by crater obliteration via steady exhumation. For these regions, we fit erosion rates. We infer that Mars light-toned sedimentary rocks typically erode at ∼102 nm/yr, when averaged over 10 km2 scales and 107-108 yr timescales. Crater-based erosion-rate determination is consistent with independent techniques, but can be applied to nearly all light-toned sedimentary rocks on Mars. Erosion is swift enough that radiolysis cannot destroy complex organic matter at some locations (e.g. paleolake deposits at SW Melas), but radiolysis is a severe problem at other locations (e.g. Oxia Planum). The data suggest that the relief of the Valles Marineris mounds is currently being reduced by wind erosion, and that dust production on Mars < 3 Gya greatly exceeds the modern reservoir of mobile dust.

  5. Natural spatial and temporal variations in groundwater chemistry in fractured, sedimentary rocks: scale and implications for solute transport

    Energy Technology Data Exchange (ETDEWEB)

    Hoven, Stephen J. van der [Department of Geography-Geology, Illinois State University, Campus Box 4400, Normal, IL 61761 (United States)]. E-mail: vanderhoven@ilstu.edu; Kip Solomon, D. [Department of Geology and Geophyics, University of Utah, 135 S. 1460 E., Room 719, Salt Lake City, UT 84112 (United States); Moline, Gerilynn R. [10 Victorian Heights, Thackeray Road, London SW8 3TD (United Kingdom)

    2005-05-15

    Natural tracers (major ions, {delta} {sup 18}O, and O{sub 2}) were monitored to evaluate groundwater flow and transport to a depth of 20 m below the surface in fractured sedimentary (primarily shale and limestone) rocks. Large temporal variations in these tracers were noted in the soil zone and the saprolite, and are driven primarily by individual storm events. During nonstorm periods, an upward flow brings water with high TDS, constant {delta} {sup 18}O, and low dissolved O{sub 2} to the water table. During storm events, low TDS, variable {delta} {sup 18}O, and high dissolved O{sub 2} water recharges through the unsaturated zone. These oscillating signals are rapidly transmitted along fracture pathways in the saprolite, with changes occurring on spatial scales of several meters and on a time scale of hours. The variations decreased markedly below the boundary between the saprolite and less weathered bedrock. Variations in the bedrock units occurred on time scales of days and spatial scales of at least 20 m. The oscillations of chemical conditions in the shallow groundwater are hypothesized to have significant implications for solute transport. Solutes and colloids that adsorb onto aquifer solids can be released into solution by decreases in ionic strength and pH. The decreases in ionic strength also cause thermodynamic undersaturation of the groundwater with respect to some mineral species and may result in mineral dissolution. Redox conditions are also changing and may result in mineral dissolution/precipitation. The net result of these chemical variations is episodic transport of a wide range of dissolved solutes or suspended particles, a phenomenon rarely considered in contaminant transport studies.

  6. Advanced statistical analysis of laser-induced breakdown spectroscopy data to discriminate sedimentary rocks based on Czerny–Turner and Echelle spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaoqin; Xu, Tao; Lin, Qingyu [Research Center of Analytical Instrumentation, College of Chemistry, Sichuan University, Chengdu 610064 (China); Liang, Long [College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Niu, Guanghui; Lai, Hongjun; Xu, Mingjun; Wang, Xu [Research Center of Analytical Instrumentation, College of Chemistry, Sichuan University, Chengdu 610064 (China); Li, Hua [College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Duan, Yixiang, E-mail: yduan@scu.edu.cn [Research Center of Analytical Instrumentation, College of Chemistry, Sichuan University, Chengdu 610064 (China)

    2014-03-01

    The correct identification of rock types is critical for understanding the origins and history of any particular rock body. Laser-induced breakdown spectroscopy (LIBS) has developed into an excellent analytical tool for geological materials research because of its numerous technical advantages compared with traditional methods. The coupling of LIBS with advanced multivariate analysis has received increasing attention because it facilitates the rapid processing of spectral information to differentiate and classify samples. In this study, we collected LIBS datasets for 16 sedimentary rocks from Triassic strata in Sichuan Basin. We compared the performance of two types of spectrometers (Czerny–Turner and Echelle) for classification of rocks using two advanced multivariate statistical techniques, i.e., partial least squares discriminant analysis (PLS-DA) and support vector machines (SVMs). Comparable levels of performance were achievable when using the two systems in the best signal reception conditions. Our results also suggest that SVM outperformed PLS-DA in classification performance. Then, we compared the results obtained when using pre-selected wavelength variables and broadband LIBS spectra as variable inputs. They provided approximately equivalent levels of performance. In addition, the rock slab samples were also analyzed directly after being polished. This minimized the analysis time greatly and showed improvement of classification performance compared with the pressed pellets. - Highlights: • SVM and PLS-DA were compared using two spectrometers to classify sedimentary rocks. • SVM combined with LIBS improved the classification accuracy compared with PLS-DA. • Minimal difference using pre-selected and broadband spectra as variable inputs • Improved classification performance achievable using polished rock slab samples.

  7. Raman spectra of carbonaceous materials in a fault zone in the Longmenshan thrust belt, China; comparisons with those of sedimentary and metamorphic rocks

    Science.gov (United States)

    Kouketsu, Yui; Shimizu, Ichiko; Wang, Yu; Yao, Lu; Ma, Shengli; Shimamoto, Toshihiko

    2017-03-01

    We analyzed micro-Raman spectra of carbonaceous materials (CM) in natural and experimentally deformed fault rocks from Longmenshan fault zone that caused the 2008 Wenchuan earthquake, to characterize degree of disordering of CM in a fault zone. Raman spectral parameters for 12 samples from a fault zone in Shenxigou, Sichuan, China, all show low-grade structures with no graphite. Low crystallinity and δ13C values (-24‰ to -25‰) suggest that CM in fault zone originated from host rocks (Late Triassic Xujiahe Formation). Full width at half maximum values of main spectral bands (D1 and D2), and relative intensities of two subbands (D3 and D4) of CM were variable with sample locations. However, Raman parameters of measured fault rocks fall on established trends of graphitization in sedimentary and metamorphic rocks. An empirical geothermometer gives temperatures of 160-230 °C for fault rocks in Shenxigou, and these temperatures were lower for highly sheared gouge than those for less deformed fault breccia at inner parts of the fault zone. The lower temperature and less crystallinity of CM in gouge might have been caused by the mechanical destruction of CM by severe shearing deformation, or may be due to mixing of host rocks on the footwall. CM in gouge deformed in high-velocity experiments exhibits slight changes towards graphitization characterized by reduction of D3 and D4 intensities. Thus low crystallinity of CM in natural gouge cannot be explained by our experimental results. Graphite formation during seismic fault motion is extremely local or did not occur in the study area, and the CM crystallinity from shallow to deep fault zones may be predicted as a first approximation from the graphitization trend in sedimentary and metamorphic rocks. If that case, graphite may lower the friction of shear zones at temperatures above 300 °C, deeper than the lower part of seismogenic zone.

  8. Sedimentary conditions of Upper Permian volcano-clastic rocks of Ayan-Yrahskiy anticlinorium (Verhoyansk-Kolyma orogen)

    Science.gov (United States)

    Astakhova, Anna; Khardikov, Aleksandr

    2013-04-01

    Sedimentation conditions of upper Permian volcano-clastic rocks of Ayan-Yurakhsky anticlinorium are the reason of discussions between researchers. It is important to correctly solve this problem. Investigation allows us to conclude that upper Permian sediments was formed due to high rate deltaic sedimentation on shelf and continental slope of epicontinental sea basin. More than 45 outcrops of upper Permian sediments were described within Ayan-Yurakhsky anticlinorium. Termochemical and X-ray phase, lithological facies, stadial, paleogeographic and others were applied. Investigation allows to classify following types: tuffs, tuffites of andesites, andesi-dacites, sandstone tuffs, siltstone tuffs and claystone tuffs. Two facies were deliniated in the research area: 1) delta channel facies 2) epicontinental sea shelf edge and continental slope. Delta channel facies are located on the south-west part of Aian-Yrahskiy anticlinorium. It is composed of silty packsand and psammitic tuff-siltstone alternation and gravel-psammitic andesi-dacitic tuffute and tuff-breccia bands. Sediments have cross-bedding, through cross-bedding, curvilinear lamination structures. Facies occurred during high rate deltaic sedimentation on the shelf of epicontinental sea. Epicontinental sea shelf edge and continental slope facies are located on the south-west part. Sediments are represented by large thickness tuff-siltstone with tuff-sandstone, tuff-madstone, tuff, tuffite bands and lenses. Large number of submarine landslides sediments provide evidence that there was high angle sea floore environment. 30-50 m diametr eruption centers were described by authors during geological traverses. They are located in Kulu river basin. Their locations are limited by deep-seated pre-ore fault which extended along Ayan-Yurakhsky anticlinorium. U-Pb SHRIMP method showed that the average age of circons, taken from eruption centers, is Permian (256,3±3,7 ma). This fact confirms our emphasis that eruption

  9. Combining high resolution vertical gradients and sequence stratigraphy to delineate hydrogeologic units for a contaminated sedimentary rock aquifer system

    Science.gov (United States)

    Meyer, Jessica R.; Parker, Beth L.; Arnaud, Emmanuelle; Runkel, Anthony C.

    2016-03-01

    Hydrogeologic units (HGUs), representing subsurface contrasts in hydraulic conductivity, form the basis for all conceptual and numerical models of groundwater flow. However, conventionally, delineation of these units relies heavily on data sets indirect with respect to hydraulic properties. Here, we use the spatial and temporal characteristics of the vertical component of hydraulic gradient (i.e., vertical gradient) as the primary line of evidence for delineating HGUs for Cambrian-Ordovician sedimentary rocks at a site in Dane County, Wisconsin. The site includes a 16 km2 area encompassing a 3 km long mixed organic contaminants plume. The vertical gradients are derived from hydraulic head profiles obtained using high resolution Westbay multilevel systems installed at 7 locations along two, orthogonal 4 km long cross-sections and monitoring to depths between 90 and 146 m with an average of 3-4 monitoring zones per 10 m. These vertical gradient cross-sections reveal 11 laterally extensive HGUs with contrasting vertical hydraulic conductivity (Kv). The position and thickness of the Kv contrasts are consistently associated with sequence stratigraphic features (maximum flooding intervals and sequence boundaries) distinguished at the site using cores and borehole geophysical logs. The same sequence stratigraphic features are also traceable across much of the Cambrian-Ordovician aquifer system of the Midwest US. The vertical gradients and sequence stratigraphy were arrived at independently and when combined provide a hydraulically calibrated sequence stratigraphic framework for the site. This framework provides increased confidence in the precise delineation and description of the nature of HGU contacts in each borehole, reduced uncertainty in interpolation of the HGUs between boreholes, and some capability to predict HGU boundaries and thickness in offsite areas where high resolution hydraulic data sets are not available. Consequently, this HGU conceptual model will

  10. Detrital zircon U-Pb and Hf isotopic data for meta-sedimentary rocks from the Heilongjiang Complex, northeastern China and tectonic implications

    Science.gov (United States)

    Zhu, Chloe Yanlin; Zhao, Guochun; Sun, Min; Han, Yigui; Liu, Qian; Eizenhöfer, Paul R.; Zhang, Xiaoran; Hou, Wenzhu

    2017-06-01

    The Heilongjiang Complex is a blueschist facies metamorphic belt located within the Zhangguangcailing Orogen between the Jiamusi and Songliao blocks in Northeast China. This complex has been regarded as an accretionary belt related to the subduction of an intervening oceanic domain between the two blocks. However, the timing of ocean closure and final amalgamation has not been well constrained, with different models arguing for a period of 210-180 Ma or sometime after 140 Ma. This work reports in-situ detrital zircon U-Pb and Hf isotopic analyses of meta-sedimentary rocks from the Heilongjiang Complex. Detrital zircons from seven meta-sedimentary rocks samples yield U-Pb ages spanning from 1690 to 167 Ma, with main populations matching those of multi-phase magmatism in the Jiamusi and Songliao blocks. Several Precambrian age groups (600 Ma, 700 Ma, 900 Ma, 960 Ma, 1200 Ma, and 1300 Ma) are consistent with the inherited zircons from the mafic rocks in the Heilongjiang Complex. A comparison with compiled data of magmatic rocks suggests that the two blocks may have been connected to each other during Permian time. Detrital zircon dating of all siliciclastic rocks yielded the youngest age component of 170 Ma, suggesting that the latest deposition of the mica schists happened at some time after 170 Ma. We propose that the Jiamusi and Songliao blocks once existed as a single block around Late Permian, which underwent a rifting event in the Permian to form a rifting basin that was subsequently evolved into an oceanic domain (Heilongjiang Ocean). The closure of the Heilongjiang Ocean occurred after 170 Ma.

  11. Origins of chromite and magnetite in sedimentary rocks deposited in a shallow water environment in the 3.2 Ga Moodies Group, South Africa

    Science.gov (United States)

    Otake, T.; Sakamoto, Y.; Itoh, S.; Yurimoto, H.; Kakegawa, T.

    2012-12-01

    *Otake, T. totake@eng.hokudai.ac.jp Div. of Sustainable Resources Engineering, Hokkaido Univ., Sapporo, Japan Sakamoto, Y. yu.sakamoto12@gmail.com Dep. of Earth Science, Tohoku Univ., Sendai, Japan Itoh, S. sitoh@ep.sci.hokudai.ac.jp Dep. of Natural History Sciences, Hokkaido Univ., Sapporo, Japan Yurimoto. H. yuri@ep.sci.hokudai.ac.jp Dep. of Natural History Sciences, Hokkaido Univ., Sapporo, Japan Kakegawa, T. kakegawa@m.tohoku.ac.jp Dep. of Earth Science, Tohoku Univ., Sendai, Japan Geochemical data from ferruginous chemical sedimentary rocks (e.g., Banded Iron Formation: BIF) have been used to reconstruct the surface environments of early Earth. However, only a few studies have investigated the geochemical characteristics of BIFs deposited in a shallow water environment during the Archean, which may have differed from those deposited in a deep water environment. Therefore, we investigated geological, petrographic and geochemical characteristics of ferruginous rocks deposited in a shallow water environment in the Moodies group, in the Barberton Greenstone Belt, South Africa. We obtained ferruginous rock samples in the Moodies group from both an outcrop and underground gold mine, and compared the characteristics of these samples. The 70 sedimentary rock samples were divided into groups based on the dominant Fe minerals they contain: Hematite-rich jaspilite (HM group), Magnetite-rich iron formation/shale/sandstone (MT group), and Siderite-rich sandstone (SD group). Samples in the HM group are predominantly composed of fine-grained quartz (rocks of the Moodies Group. These results suggest that Cr and U were chemically mobile, possibly as oxidized species, in the Earth's surface environment at ~3.2 Ga.

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

    Science.gov (United States)

    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

  13. Evolving Yangtze River reconstructed by detrital zircon U-Pb dating and petrographic analysis of Miocene marginal Sea sedimentary rocks of the Western Foothills and Hengchun Peninsula, Taiwan

    Science.gov (United States)

    Zhang, Xinchang; Huang, Chiyue; Wang, Yuejun; Clift, Peter D.; Yan, Yi; Fu, Xiaowei; Chen, Duofu

    2017-04-01

    The timing of the establishment of the Yangtze River, whether prior to the early Miocene ( 24 Ma) or more recently ( 2 Ma), has been a point of much debate. Here we applied detrital zircon U-Pb dating to Miocene sedimentary rocks from Taiwan and to estuary sands from modern rivers in SE China to trace sediment provenance and to further constrain the evolution of the Yangtze River. Detrital zircon U-Pb ages from Miocene sandstones of the Western Foothills show similar age spectra to Miocene and modern sediments in the Yangtze River drainage and some similarity to the Minjiang River sediments. However, they differ significantly from ages in some sandstones from the Hengchun Peninsula accretionary prism and from the estuary sands of the Jiulongjiang River. This information, together with petrographic and sedimentary facies analysis, argues that the Jiulongjiang and Minjiang Rivers were major sources to some Hengchun Peninsula turbidites ( 12 Ma), while synchronous sedimentation in the Western Foothills was supplied from the Yangtze, Minjiang (or similar river), and possibly even the Yellow River. These sediments were transported southward/eastward via rivers or channels to the marginal sedimentary basins now inverted in the Western Foothills in Taiwan. The Yangtze River must have been established prior to the middle Miocene.

  14. Comparison of alternative representations of hydraulic-conductivity anisotropy in folded fractured-sedimentary rock: Modeling groundwater flow in the Shenandoah Valley (USA)

    Science.gov (United States)

    Yager, R.M.; Voss, C.I.; Southworth, S.

    2009-01-01

    A numerical representation that explicitly represents the generalized three-dimensional anisotropy of folded fractured-sedimentary rocks in a groundwater model best reproduces the salient features of the flow system in the Shenandoah Valley, USA. This conclusion results from a comparison of four alternative representations of anisotropy in which the hydraulic-conductivity tensor represents the bedrock structure as (model A) anisotropic with variable strikes and dips, (model B) horizontally anisotropic with a uniform strike, (model C) horizontally anisotropic with variable strikes, and (model D) isotropic. Simulations using the US Geological Survey groundwater flow and transport model SUTRA are based on a representation of hydraulic conductivity that conforms to bedding planes in a three-dimensional structural model of the valley that duplicates the pattern of folded sedimentary rocks. In the most general representation, (model A), the directions of maximum and medium hydraulic conductivity conform to the strike and dip of bedding, respectively, while the minimum hydraulic-conductivity direction is perpendicular to bedding. Model A produced a physically realistic flow system that reflects the underlying bedrock structure, with a flow field that is significantly different from those produced by the other three models. ?? Springer-Verlag 2009.

  15. Sedimentary connection between rock glaciers and torrential channels: definition, inventory and quantification from a test area in the south-western Swiss Alps

    Science.gov (United States)

    Kummert, Mario; Barboux, Chloé; Delaloye, Reynald

    2017-04-01

    Permafrsot creep is an important sediment transfer process in periglacial alpine hillslopes (Delaloye et al. 2010). Rock glaciers are the visible expression of mountain permafrost creep (Delaloye 2004). Large volumes of rock debris originating from headwalls, moraines and weathering deposits are slowly transported within rock glaciers from their rooting zone to their fronts. In the Alps, most rock glaciers can be considered as sediment traps, because the sediment output at their margin is usually limited (Gärtner-Roer 2012). However, cases of rock glacier supplying torrential channels with sediments have been documented (e.g. Lugon and Stoffel 2010, Delaloye et al. 2013) Such rock glaciers can act as a sediment source for the triggering of gravitational processes propagating further downstream. Moreover, in such configuration the amount of sediment available is not a finite volume but is gradually renewed or increased as the rock glacier advances. These cases are therefore very specific, especially in the perspective of natural hazards assessment and mitigation. However, in the Alps very little is known about such type of rock glaciers. In addition, the sediment transfer rates between the fronts of the rock glaciers and the torrents are often not known. In this context, our study aims at (i) defining better the configurations in which a sedimentary connection exists between rock glaciers and torrential channels, (ii) localizing the cases of active rock glaciers connected to the torrential network and (iii) estimating approximate sediment transfer rates between the fronts and the torrential gullies. For that purpose, an inventory method for the classification of torrential catchments based on the analysis of aerial images and the computation of connectivity indexes have been developped. In addition, sediment transfer rates were estimated taking into account the geometry of the frontal areas and the velocity rates of the rock glaciers derived from DInSAR data. In

  16. Formation of systems of incompact bands parallel to the compression axis in the unconsolidated sedimentary rocks: A model

    Science.gov (United States)

    Mukhamediev, Sh. A.; Ul'Kin, D. A.

    2011-10-01

    Uniaxial compression of poorly lithified rocks leads to the formation of thin incompact layers (or bands, in the two-dimensional case) parallel to the compression axis, which are characterized by increased porosity. The standard model of the formation of such bands, as well as deformation bands of other types, associates them with the narrow zones of localization of plastic deformations. In the case of decompaction, it is assumed that transverse tensile deformations are localized within the band, which cause the band to dilate. Here, the formation of a band of localized deformations is treated as a loss-of-stability phenomenon. Based on observations, we propose a fundamentally different model of incompact bands formation, according to which the microdefects in sediment packing (pores) rather than the deformations are localized in the narrow zones. The localization of pores, which are initially randomly distributed in the medium, occurs as a result of their migration through the geomaterial. The migration and subsequent localization of pores are driven by a common mechanism, namely, a trend of a system to lower its total energy (small variations in total energy are equal to the increment of free energy minus the work of external forces). Migration of a single pore in a granular sedimentary rock is caused by the force f driving the defect. This force was introduced by J. Eshelby (1951; 1970). An important feature of our model is that the formation of an incompact band here does not have a sense of a loss of stability. Quite the contrary, the formation of incompact bands is treated as a gradual process spread over time. In this context, the origination of incompact band systems directly follows from our model itself, without any a priori assumptions postulating the existence of such systems and without any special tuning of the model parameters. Moreover, based on the proposed model, we can predict the incompact bands to always occur in the form of systems rather than

  17. New approaches in the indirect quantification of thermal rock properties in sedimentary basins: the well-log perspective

    DEFF Research Database (Denmark)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    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...

  18. Geochemical constraints on the oldest arc rocks of the Arabian-Nubian Shield: The late Mesoproterozoic to late Neoproterozoic (?) Sa'al volcano-sedimentary complex, Sinai, Egypt

    Science.gov (United States)

    Ali-Bik, Mohamed W.; Abd El Rahim, Said H.; Wahab, Wael Abdel; Abayazeed, Salwa D.; Hassan, Safaa M.

    2017-07-01

    The Wadi Sa'al metamorphosed volcano-sedimentary complex represents the deepest exposed stratigraphic levels of the Arabian-Nubian Shield (ANS). Recent isotopic ages (1.12-0.95 Ga, Be'eri-Shlevin et al., 2012) assigned the Sa'al complex as the oldest arc rocks of the ANS (pre-Pan-African?). It encompasses a wide variety of non-consanguineous, late Mesoproterozoic to late Neoproterozoic (?) rock units that preserve a complicated and protracted record of orogenic and tectonic assembly. They experienced regional low-pressure greenschist up to amphibolite facies metamorphism. The tectono-stratigraphic rock units of the Wadi Sa'al complex can be distinguished into two superimposed metavolcanic formations (Agramiya and post-Ra'ayan), separated by the metasedimentary Ra'ayan Formation. Both the Agramiya and post-Ra'ayan metavolcanics comprise basalts, basaltic andesite and rhyolite. The Ra'ayan metasediments encompass metagreywacke, semi-metapelite and metapelite. Geochemical consanguinity, tectonic setting and petrogenesis of the different rock units of the Sa'al complex are addressed. The metavolcanics of the Sa'al complex imply calc-alkaline affinities with subordinate tholeiitic signature and probable island-arc setting. The Ra'ayan metasedimentary rocks were accumulated as fluvial sediments in basins adjacent to their uplifted volcanic protoliths (Agramiya Formation). The detritus was deposited in fresh-water environment. New geological mapping was undertaken for the area using remote sensing and GIS techniques. Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) band rationing-based images (b6/b4, b6/b7, and b4/b2) effectively discriminate the different basement rock units of the Wadi Sa'al area from each other.

  19. Catagenesis of terrigenous rocks in the neoproterozoic intracratonic sedimentary basins and its effect on the formation of unconformity-type uranium mineralization

    Science.gov (United States)

    Andreeva, O. V.

    2012-02-01

    Mineral transformation of host rocks and localization of orebodies at the unconformity-type uranium deposits are considered for the Karku deposit in the northern Ladoga region. It is shown that the great depth of uranium mineral formation and the peculiar composition of host rocks, along with temperature and chemistry of fluids, played a critical role in variation of lithostatic and fluid pressure, porosity, and permeability. The compaction of quartz sandstone and gravelstone, which are typical host rocks at unconformity-type deposits, the development of microstylolithic sutures, conformal structures, pressure solution and deposition of quartz in free pores gave rise to the closure or constraint of pore space and to increase in pore pressure of fluids in the deep part of the Riphean troughs with approaching lithostatic loading. A transitional zone between hydrostatic and lithostatic pressure controlled localization of orebodies and was decisive for uranium mineral formation. This zone coincided with the Riphean-Paleoproterozoic unconformity and sank somewhat into the crystalline basement. Below this transitional zone, the intergranular fluid was under a pressure that was close to the pressure on solid phases, i.e., P tot ≈ P fl. The reliability of this phenomenon is confirmed by cessation of pressure solution-redeposition of quartz and distinct deceleration of dehydration of hydrous minerals. As is shown for the Karku deposit, the highly hydrated clay minerals of the illite-smectite series are widespread in its subore portion and lacking at the supraore levels along with termination of quartz regeneration. It is suggested that a zone of superhigh fluid pressure in deep parts of sedimentary basins constrains localization of uranium orebodies by structural and stratigraphic unconformity between Riphean and Paleoproterozoic rocks. It is stated that altered wall rocks at the unconformity-type uranium deposits cannot be identified with products of hydrothermal phyllic

  20. Classes of organic molecules targeted by a methanogenic microbial consortium grown on sedimentary rocks of various maturities

    Directory of Open Access Journals (Sweden)

    Margaux eMesle

    2015-06-01

    Full Text Available Organic-rich shales are populated by methanogenic consortia that are able to degrade the fossilized organic matter into methane gas. To identify the organic fraction effectively degraded, we have sequentially depleted two types of organic-rich rocks, shales and coal, at two different maturities, by successive solvent extractions to remove the most soluble fractions (maltenes and asphaltenes and isolate kerogen. We show the ability of the consortia to produce methane from all rock samples, including those containing the most refractory organic matter, i.e. the kerogen. Shales yielded higher methane production than lignite and coal. Mature rocks yielded more methane than immature rocks. Surprisingly, the efficiency of the consortia was not influenced by the removal of the easily biodegradable fractions contained in the maltenes and asphaltenes. This suggests that one of the limitations of organic matter degradation in situ may be the accessibility of the carbon and energy source. Indeed, bitumen has a colloidal structure that may limit the accessibility to asphaltenes in the bulk rock. Solvent extractions might favor the access to asphaltenes and kerogen by modifying the spatial organization of the molecules in the rock matrix.

  1. Ground-water system, estimation of aquifer hydraulic properties, and effects of pumping on ground-water flow in Triassic sedimentary rocks in and near Lansdale, Pennsylvania

    Science.gov (United States)

    Senior, Lisa A.; Goode, Daniel J.

    1999-01-01

    Ground water in Triassic-age sedimentary fractured-rock aquifers in the area of Lansdale, Pa., is used as drinking water and for industrial supply. In 1979, ground water in the Lansdale area was found to be contaminated with trichloroethylene, tetrachloroethylene, and other man-made organic compounds, and in 1989, the area was placed on the U.S. Environmental Protection Agency's (USEPA) National Priority List as the North Penn Area 6 site. To assist the USEPA in the hydrogeological assessment of the site, the U.S. Geological Survey began a study in 1995 to describe the ground-water system and to determine the effects of changes in the well pumping patterns on the direction of ground-water flow in the Lansdale area. This determination is based on hydrologic and geophysical data collected from 1995-98 and on results of the simulation of the regional ground-water-flow system by use of a numerical model.Correlation of natural-gamma logs indicate that the sedimentary rock beds strike generally northeast and dip at angles less than 30 degrees to the northwest. The ground-water system is confined or semi-confined, even at shallow depths; depth to bedrock commonly is less than 20 feet (6 meters); and depth to water commonly is about 15 to 60 feet (5 to 18 meters) below land surface. Single-well, aquifer-interval-isolation (packer) tests indicate that vertical permeability of the sedimentary rocks is low. Multiple-well aquifer tests indicate that the system is heterogeneous and that flow appears primarily in discrete zones parallel to bedding. Preferred horizontal flow along strike was not observed in the aquifer tests for wells open to the pumped interval. Water levels in wells that are open to the pumped interval, as projected along the dipping stratigraphy, are drawn down more than water levels in wells that do not intersect the pumped interval. A regional potentiometric map based on measured water levels indicates that ground water flows from Lansdale towards discharge

  2. Average sedimentary rock rare Earth element patterns and crustal evolution: Some observations and implications from the 3800 Ma ISUA supracrustal belt, West Greenland

    Science.gov (United States)

    Dymek, R. F.; Boak, J. L.; Gromet, L. P.

    1983-01-01

    Rare earth element (REE) data is given on a set of clastic metasediments from the 3800 Ma Isua Supracrustal belt, West Greenland. Each of two units from the same sedimentary sequence has a distinctive REE pattern, but the average of these rocks bears a very strong resemblance to the REE pattern for the North American Shale Composite (NASC), and departs considerably from previous estimates of REE patterns in Archaean sediments. The possibility that the source area for the Isua sediments resembled that of the NASC is regarded as highly unlikely. However, REE patterns like that in the NASC may be produced by sedimentary recycling of material yielding patterns such as are found at Isua. The results lead to the following tentative conclusions: (1) The REE patterns for Isua Seq. B MBG indicate the existence of crustal materials with fractionated REE and negative Eu anomalies at 3800 Ma, (2) The average Seq. B REE pattern resembles that of the North American Shale Composite (NASC), (3) If the Seq. B average is truly representative of its crustal sources, then this early crust could have been extensively differentiated. In this regard, a proper understanding of the NASC pattern, and its relationship to post-Archaean crustal REE reservoirs, is essential, (4) The Isua results may represent a local effect.

  3. Argon broad ion beam tomography in a cryogenic scanning electron microscope: a novel tool for the investigation of representative microstructures in sedimentary rocks containing pore fluid.

    Science.gov (United States)

    Desbois, G; Urai, J L; Pérez-Willard, F; Radi, Z; Offern, S; Burkart, I; Kukla, P A; Wollenberg, U

    2013-03-01

    The contribution describes the implementation of a broad ion beam (BIB) polisher into a scanning electron microscope (SEM) functioning at cryogenic temperature (cryo). The whole system (BIB-cryo-SEM) provides a first generation of a novel multibeam electron microscope that combines broad ion beam with cryogenic facilities in a conventional SEM to produce large, high-quality cross-sections (up to 2 mm(2)) at cryogenic temperature to be imaged at the state-of-the-art SEM resolution. Cryogenic method allows detecting fluids in their natural environment and preserves samples against desiccation and dehydration, which may damage natural microstructures. The investigation of microstructures in the third dimension is enabled by serial cross-sectioning, providing broad ion beam tomography with slices down to 350 nm thick. The functionalities of the BIB-cryo-SEM are demonstrated by the investigation of rock salts (synthetic coarse-grained sodium chloride synthesized from halite-brine mush cold pressed at 150 MPa and 4.5 GPa, and natural rock salt mylonite from a salt glacier at Qom Kuh, central Iran). In addition, results from BIB-cryo-SEM on a gas shale and Boom Clay are also presented to show that the instrument is suitable for a large range of sedimentary rocks. For the first time, pore and grain fabrics of preserved host and reservoir rocks can be investigated at nm-scale range over a representative elementary area. In comparison with the complementary and overlapping performances of the BIB-SEM method with focused ion beam-SEM and X-ray tomography methods, the BIB cross-sectioning enables detailed insights about morphologies of pores at greater resolution than X-ray tomography and allows the production of large representative surfaces suitable for FIB-SEM investigations of a specific representative site within the BIB cross-section. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  4. A comparative study of discrete fracture network and equivalent continuum models for simulating flow and transport in the far field of a hypothetical nuclear waste repository in crystalline host rock

    Science.gov (United States)

    Hadgu, Teklu; Karra, Satish; Kalinina, Elena; Makedonska, Nataliia; Hyman, Jeffrey D.; Klise, Katherine; Viswanathan, Hari S.; Wang, Yifeng

    2017-10-01

    One of the major challenges of simulating flow and transport in the far field of a geologic repository in crystalline host rock is related to reproducing the properties of the fracture network over the large volume of rock with sparse fracture characterization data. Various approaches have been developed to simulate flow and transport through the fractured rock. The approaches can be broadly divided into Discrete Fracture Network (DFN) and Equivalent Continuum Model (ECM). The DFN explicitly represents individual fractures, while the ECM uses fracture properties to determine equivalent continuum parameters. We compare DFN and ECM in terms of upscaled observed transport properties through generic fracture networks. The major effort was directed on making the DFN and ECM approaches similar in their conceptual representations. This allows for separating differences related to the interpretation of the test conditions and parameters from the differences between the DFN and ECM approaches. The two models are compared using a benchmark test problem that is constructed to represent the far field (1 × 1 × 1 km3) of a hypothetical repository in fractured crystalline rock. The test problem setting uses generic fracture properties that can be expected in crystalline rocks. The models are compared in terms of the: 1) effective permeability of the domain, and 2) nonreactive solute breakthrough curves through the domain. The principal differences between the models are mesh size, network connectivity, matrix diffusion and anisotropy. We demonstrate how these differences affect the flow and transport. We identify the factors that should be taken in consideration when selecting an approach most suitable for the site-specific conditions.

  5. Geochemistry of Precambrian sedimentary rocks used to solve stratigraphical problems: An example from the Neoproterozoic Volta basin, Ghana

    DEFF Research Database (Denmark)

    Kalsbeek, F.; Frei, Robert

    2010-01-01

    units, in upward succession the Bombouaka, Oti and Obosum Groups, but poor exposure has resulted in major disagreements on stratigraphical correlations and on the areal extents of these units. Geochemical data (major and trace element concentrations as well as Rb–Sr, Pb and Sm–Nd isotope data......) on siltstones and mudstones, intercalated with the sandstones from the different units, were used in an attempt to solve some of these problems. Siltstones and mudstones from the Bombouaka Group can be unequivocally distinguished from similar rocks from the Oti and Obosum Groups by higher K2O and Rb, larger Eu...... of correlation between the concentrations of K and Rb, and Ca and Sr, indicate that mobility of these elements did not significantly change their concentrations during surface weathering. The clear geochemical distinction between mudstones and siltstones from the Bombouaka Group and similar rocks from the Oti...

  6. Determination of. gamma. -ray absorbed dose rates in air above igneous and sedimentary rocks on SW Dartmoor

    Energy Technology Data Exchange (ETDEWEB)

    Day, L.R.; Zumpe, H.H. (North East London Polytechnic (UK))

    1984-01-01

    Calculations have been made to determine the ..gamma..-ray absorbed dose rate in air above different types of rock using a single group radiation attenuation model. The results obtained are then compared with dose rates measured with a compensated environmental Geiger-Muller counter. The measurements were made above granite, slate, and dolerite and also on alluvium overlying granite. The comparison shows good agreement between measured and calculated dose rates taking into account the limitations inherent in both the calculations and measurements.

  7. Germanium Enrichments in Sedimentary Rocks in Gale Crater, Mars: Constraining the Timing of Alteration and Character of the Protolith

    Science.gov (United States)

    Berger, J. A.; Schmidt, M. E.; Gellert, R.; Campbell, J. L.; Boyd, N. I.; Elliott, B. E.; Fisk, M. R.; King, P. L.; Ming, D. W.; Perrett, G. M.; hide

    2015-01-01

    Rocks enriched in Ge have been discovered in Gale Crater, Mars, by the Alpha-particle X-ray spectrometer (APXS) on the Mars Science Lab (MSL) rover, Curiosity. The Ge concentrations in Gale Crater (commonly >50 ppm) are remarkably high in comparison to Earth, where Ge ranges from 0.5-4.0 ppm in igneous rocks and 0.2-3.3 ppm in siliciclastic sediment. Primary meteoritic input is not likely the source of high Ge because Ge/Ni in chondrites (approx.0.003) and irons (Gale rocks (0.08-0.2). Earth studies show Ge is a useful geochemical tracer because it is coherent with Si during magmatic processes and Ge/Si varies less than 20% in basalts. Ge and Si fractionate during soil/regolith weathering, with Ge preferentially sequestered in clays. Ge is also concentrated in Cu- and Zn-rich hydrothermal sulfide deposits and Fe- and Mnrich oxide deposits. Other fluid-mobile elements (K, Zn, Cl, Br, S) are also enriched at Gale and further constrain aqueous alteration processes. Here, we interpret the sediment alteration history and present a possible model for Ge enrichments at Gale involving fluid alteration of the protolith.

  8. Volcano-sedimentary characteristics in the Abu Treifiya Basin, Cairo-Suez District, Egypt: Example of dynamics and fluidization over sedimentary and volcaniclastic beds by emplacement of syn-volcanic basaltic rocks

    Science.gov (United States)

    Khalaf, E. A.; Abdel Motelib, A.; Hammed, M. S.; El Manawi, A. H.

    2015-12-01

    This paper describes the Neogene lava-sediment mingling from the Abu Treifiya Basin, 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 Basin. Characterization of the facies architecture and textural framework of peperites was carried out through detailed description and interpretation of their outcrops. The peperites and sedimentary 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 large 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

  9. Geochemistry of the metasedimentary rocks from the Male Karpaty Mts. (Western Carpathians): implications for protolith, provenance, sedimentary environment and tectonic setting

    Science.gov (United States)

    Meres, S.; Ivan, P.

    2003-04-01

    The Male Karpaty Mts. represent connecting link between the Western Carpathians and Eastern Alps. They are composed of (1) Early Paleozoic basement and (2) Mesozoic cover. Based on lithology and basalt geochemistry the Early Paleozoic basement is divided into two lithostratigraphic groups: (1) Pernek Group represented by incomplete dismembered ophiolite sequences Pre-Visean in age and (2) Pezinok Group supposed to be a fragment of the Devonian extensional rift basin. Both groups were intruded by granitoid batoliths 348±4 My old and underwent contact or periplutonic metamorphic alterations variable in intensity. Metasedimentary rocks of the Pernek Group are represented by small amount of black shales and metacherts associated with small lenses of stratiform pyrite ores. In the Pezinok Group metasedimentary rocks are highly dominated. Phyllites and gneisses sporadically with the organic matter admixture belong to most frequent rock types. Metamorphosed limestones associated with basaltic hyaloclastites occur sporadically only. The distribution of trace elements with the limited fractionation during weathering, transport and deposition processes and immobile in metamorphosis (REE, Th, Hf, Sc) have been mainly used for protolith, provenance and depositional environment studies. Chemical composition of the black shales from the Pernek Group indicate their mixed sedimentary protolith which was formed in oceanic environment and was composed of four components: (1) pelagic chert, (2) organic matter, (3) fine-grained terrigenous component and (4) weathered/hydrothermally altered basalt close to N-MORB. Negative Ce-anomaly, LaN/YbN<6 and Th/Yb<2 are typical. Protolith of metasedimentary rocks (including rocks with organic matter admixture) from the Pezinok Group seems to be close to the immature greywackes of the ensialic island arc provenance derived from an acidic/intermediate magmatic source. They display no Ce-anomaly, negative Eu-anomaly typical for greywackes (Eu

  10. Phosphate Stability in Diagenetic Fluids Constrains the Acidic Alteration Model for Lower Mt. Sharp Sedimentary Rocks in Gale Crater, Mars

    Science.gov (United States)

    Berger, J. A.; Schmidt, M. E.; Izawa, M. R. M.; Gellert, R.; Ming, D. W.; Rampe, E. B.; VanBommel, S. J.; McAdam, A. C.

    2016-01-01

    The Mars rover Curiosity has encountered silica-enriched bedrock (as strata and as veins and associated halos of alteration) in the largely basaltic Murray Fm. of Mt. Sharp in Gale Crater. Alpha Particle X-ray Spectrometer (APXS) investigations of the Murray Fm. revealed decreasing Mg, Ca, Mn, Fe, and Al, and higher S, as silica increased (Fig. 1). A positive correlation between SiO2 and TiO2 (up to 74.4 and 1.7 wt %, respectively) suggests that these two insoluble elements were retained while acidic fluids leached more soluble elements. Other evidence also supports a silica-retaining, acidic alteration model for the Murray Fm., including low trace element abundances consistent with leaching, and the presence of opaline silica and jarosite determined by CheMin. Phosphate stability is a key component of this model because PO4 3- is typically soluble in acidic water and is likely a mobile ion in diagenetic fluids (pH less than 5). However, the Murray rocks are not leached of P; they have variable P2O5 (Fig. 1) ranging from average Mars (0.9 wt%) up to the highest values in Gale Crater (2.5 wt%). Here we evaluate APXS measurements of Murray Fm. bedrock and veins with respect to phosphate stability in acidic fluids as a test of the acidic alteration model for the Lower Mt. Sharp rocks.

  11. Geochemistry of host rocks in the Howards Pass district, Yukon-Northwest Territories, Canada: implications for sedimentary environments of Zn-Pb and phosphate mineralization

    Science.gov (United States)

    Slack, John F.; Falck, Hendrik; Kelley, Karen D.; Xue, Gabriel G.

    2017-01-01

    Detailed lithogeochemical data are reported here on early Paleozoic sedimentary rocks that host the large Howards Pass stratiform Zn-Pb deposits in Yukon-Northwest Territories. Redox-sensitive trace elements (Mo, Re, V, U) and Ce anomalies in members of the Duo Lake Formation record significant environmental changes. During the deposition of lower footwall units (Pyritic siliceous and Calcareous mudstone members), bottom waters were anoxic and sulphidic, respectively; these members formed in a marginal basin that may have become increasingly restricted with time. Relative to lower members, a major environmental change is proposed for deposition of the overlying Lower cherty mudstone member, which contains phosphorite beds up to ∼0.8 m thick in the upper part, near the base of the Zn-Pb deposits. The presence of these beds, together with models for modern phosphorite formation, suggests P input from an upwelling system and phosphorite deposition in an upper slope or outer shelf setting. The overlying Active mudstone member contains stratabound to stratiform Zn-Pb deposits within black mudstone and gray calcareous mudstone. Data for unmineralized black mudstone in this member indicate deposition under diverse redox conditions from suboxic to sulphidic. Especially distinctive in this member are uniformly low ratios of light to heavy rare earth elements that are unique within the Duo Lake Formation, attributed here to the dissolution of sedimentary apatite by downward-percolating acidic metalliferous brines. Strata that overlie the Active member (Upper siliceous mudstone member) consist mainly of black mudstone with thin (0.5–1.5 cm) laminae of fine-grained apatite, recording continued deposition on an upper slope or outer shelf under predominantly suboxic bottom waters. Results of this study suggest that exploration for similar stratiform sediment-hosted Zn-Pb deposits should include the outer parts of ancient continental margins, especially at and near

  12. Estimation of groundwater recharge in sedimentary rock aquifer systems in the Oti basin of Gushiegu District, Northern Ghana

    Science.gov (United States)

    Afrifa, George Yamoah; Sakyi, Patrick Asamoah; Chegbeleh, Larry Pax

    2017-07-01

    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 sedimentary 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 largely 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.

  13. The use of surface-enhanced Raman scattering for detecting molecular evidence of life in rocks, sediments, and sedimentary deposits.

    Science.gov (United States)

    Bowden, Stephen A; Wilson, Rab; Cooper, Jonathan M; Parnell, John

    2010-01-01

    Raman spectroscopy is a versatile analytical technique capable of characterizing the composition of both inorganic and organic materials. Consequently, it is frequently suggested as a payload on many planetary landers. Only approximately 1 in every 10(6) photons are Raman scattered; therefore, the detection of trace quantities of an analyte dispersed in a sample matrix can be much harder to achieve. To overcome this, surface-enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS) both provide greatly enhanced signals (enhancements between 10(5) and 10(9)) through the analyte's interaction with the locally generated surface plasmons, which occur at a "roughened" or nanostructured metallic surface (e.g., Cu, Au, and Ag). Both SERS and SERRS may therefore provide a viable technique for trace analysis of samples. In this paper, we describe the development of SERS assays for analyzing trace amounts of compounds present in the solvent extracts of sedimentary deposits. These assays were used to detect biological pigments present in an Arctic microoasis (a small locale of elevated biological productivity) and its detrital regolith, characterize the pigmentation of microbial mats around hydrothermal springs, and detect fossil organic matter in hydrothermal deposits. These field study examples demonstrate that SERS technology is sufficiently mature to be applied to many astrobiological analog studies on Earth. Many current and proposed imaging systems intended for remote deployment already posses the instrumental components needed for SERS. The addition of wet chemistry sample processing facilities to these instruments could yield field-deployable analytical instruments with a broadened analytical window for detecting organic compounds with a biological or geological origin.

  14. Comparative geology and geochemistry of sedimentary-rock-hosted (Carlin Type) gold deposits in the People's Republic of China and in Nevada, USA

    Science.gov (United States)

    Li, Zhiping; Peters, Stephen G.

    1998-01-01

    Sedimentary-rock-hosted (Carlin-type) gold deposits have been considered economically significant and geologically distinct since the early 1960's. This report consists of a nine-part text and an interactive database. This small database is to help Western companies get more information about these gold deposits in China, and to help geologists who are interested in world Carlin-type deposits conduct research on them. Because of their economic significance and geological distinctiveness, these deposits have caught the interest of economic geologists all over the world since the early 1960's. Similar deposits have been discovered in China, Australia, Dominican Republic, Spain, and Russia besides Nevada. Perhaps most significant are the 165 Carlin-type gold deposits that were found in southwest China during the past 15 years. Of these, at least 19 deposits have proven to be of substantial tonnage, making China the second leading country to exploit such deposits. With the increasing interest in Chinese Carlin-type gold deposits, some western companies and geologists desire to get more information about these Chinese deposits. This seems to have been very difficult because the literature was in Chinese. It is estimated that several hundred scientific publications (including papers, books, and technical reports) have been published. This database of Chinese Carlin-type Gold deposits is built on the documentation published during the most recent 10 years and includes six subjects, which consist of 165 records and 30 fields. A new Proterozoic-age sedimentary-rock-hosted gold deposit in northeastern P.R. China also is described. Note that for the old version 1.1 on the CD-ROM, the latitude and longitude locations of the mineral occurrences have been estimated from sketch maps and journal articles and are not intended for digital analysis. One of the improvements in this version 1.2 is the accuracy of geographic data. Version 1.3 updates to the database and includes maps

  15. Paleomagnetic studies of volcanic rocks in Siberia and sedimentary rocks in Southern Alberta: From long-term geomagnetic field variations to age determinations

    Science.gov (United States)

    Blanco Acuna, Dunia

    Paleomagnetism is a fundamental tool to understand the ancient variations of Earth's magnetic field through time. Important applications to geochronology and paleography come from interpreting the variations of the planetary magnetic vector. This dissertation explores the different applications of paleomagnetism to uncover important characteristics of the paleointensity magnetic field during the Permo-Triassic boundary and the nature of the apparent polar wander path (APWP) of Siberia, and to create geochronological frameworks for kimberlites in the Siberian platform and for sediments at the Western Canada Sedimentary Basin. Detailed absolute paleointensity measurements from Permo-Triassic sills at the Siberian platform are studied to determine the existence of a low dipole field, which has been previously reported in the area. We found a mean virtual dipolar moment value of 6.01 +/- 1.45 x 1022 Am 2 which is over 50% higher than the results previously obtained by other authors. Diamondiferous kimberlite pipes are exposed across the north-central part of the Siberian platform. The age of the magmatic activity cannot be clearly determined from isotopic age data---this is the reason why new paleomagnetic poles from four kimberlite pipes are obtained to study their paleomagnetic age. On the basis of a comparison with the Siberian APWP, we estimate the age of the kimberlite magmatism. The acquired paleomagnetic ages span from the Early Silurian to the Middle Late Jurassic. Magnetostratigraphic analysis is used as a dating tool on three deep drilling cores that penetrate Santonian-Campanian strata in southern Alberta, Canada. Chrons 34n and 33r are clearly identified from the studied sections---providing a high-resolution age boundary that creates new age boundaries between adjacent stratigraphic units. In addition, normal polarity zones are observed within C33r, previously described as reverse polarity over its entire length. Siberian APWP contains long unresolved

  16. Late Ediacaran volcano-sedimentary successions of southern Sinai (Egypt): tracing the evolution from late- to post-collisional volcanism and its relation to A-type rocks

    Science.gov (United States)

    Azer, Mokhles; Asimow, Paul; Obeid, Mohamed; Price, Jason; Wang, Max

    2017-04-01

    The Late Ediacaran post-collisional volcano-sedimentary successions exposed in southern Sinai (Egypt) represent the last stage of magmatic activity associated with assembly of the northernmost segment of the Neoproterozoic Arabian-Nubian Shield. To clarify the age and tempo of post-collisional activity, three volcanic successions from southern Sinai were selected for the present study: the Sahiya, Iqna Shar'a and Meknas volcanics. They comprise a series of intermediate to silicic volcanic flows and their pyroclastic rocks. New zircon U-Pb dating by SIMS of the lava flows from the three successions yielded ages ranging between ca. 619 to 600 Ma. Combined with field evidence and the geochemical data, the obtained SIMS zircon ages enable us to recognize two phases of volcanic activity in southern Sinai at ca. 619-615 Ma and 606-600 Ma. Both age groups were found within the more northerly volcanic successions at Iqna Shar'a and Meknas and in both these sequences the younger phase uncomformably overlies the older phase. Only the older ages, ca. 615-619 Ma, were found in the Sahiya volcanics, exposed at the southern tip of Sinai. The ages of the youngest calc-alkaline volcanics in the study areas are similar to or slightly younger than the earliest phases of alkaline volcanism in southern Sinai, indicating coeval extrusion of calc-alkalic and alkalic A-type rocks. This observation corroborates similar observations documenting cogenetic calc-alkalic and alkalic plutons in the surrounding areas in southern Sinai. Geochemically, the volcanic rocks of the three successions display large silica variations and are mostly medium- to high-K calc-alkaline rocks. The first phase, from ca. 619-615 Ma, observed in all three volcanic suites, comprises basaltic andesite, andesite and dacite, whereas the second phase, from ca. 606-600 Ma and observed only in the northern volcanic suites (Iqna Shar'a and Meknas), comprises dacite, rhyodacite and rhyolite. In the Sahiya succession basal

  17. Review and reconnaissance of the hydrogeology of Tertiary sedimentary rocks in the vicinity of Frenchman Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Prothro, L.B.; Drellack, S.L. Jr.

    1997-09-01

    Work is currently underway within the Underground Test Area (UGTA) subproject of the US Department of Energy/Nevada Operations Office Environmental Restoration Program to develop corrective action plans in support of the overall corrective action strategy for the Nevada Test Site (NTS) as established in the Federal Facility Agreement and Consent Order (FFACO, 1996). A closure plan is currently being developed for Frenchman Flat, which has been identified in the FFACO as a Corrective Action Unit (CAU). Part of this effort requires that hydrogeologic data be compiled for inclusion in a CAU-specific hydrologic flow and transport model that will be used to predict contaminant boundaries. Hydrogeologic maps and cross sections are currently being prepared for use in the model to define the nature and extent of aquifers and confining units that might influence the flow of contaminated groundwater from underground nuclear tests conducted in Frenchman Flat. During this effort, it has been found that older Tertiary-age sediments might be hydrogeologically important in the Frenchman Flat model area. Although the character and extent of these units are poorly known, there is reason to believe that in some parts of Frenchman Flat they may lie between the regional Lower Carbonate Aquifer (LCA) and the younger Tertiary saturated alluvium and volcanic units in which several underground nuclear tests were conducted. It was not possible to quickly determine their extent, or ascertain whether or not these units might act as confining units or aquifers. The work described in this report was done to gain a better understanding of the hydrogeology of these rocks.

  18. An analysis of fracture trace patterns in areas of flat-lying sedimentary rocks for the detection of buried geologic structure. [Kansas and Texas

    Science.gov (United States)

    Podwysocki, M. H.

    1974-01-01

    Two study areas in a cratonic platform underlain by flat-lying sedimentary rocks were analyzed to determine if a quantitative relationship exists between fracture trace patterns and their frequency distributions and subsurface structural closures which might contain petroleum. Fracture trace lengths and frequency (number of fracture traces per unit area) were analyzed by trend surface analysis and length frequency distributions also were compared to a standard Gaussian distribution. Composite rose diagrams of fracture traces were analyzed using a multivariate analysis method which grouped or clustered the rose diagrams and their respective areas on the basis of the behavior of the rays of the rose diagram. Analysis indicates that the lengths of fracture traces are log-normally distributed according to the mapping technique used. Fracture trace frequency appeared higher on the flanks of active structures and lower around passive reef structures. Fracture trace log-mean lengths were shorter over several types of structures, perhaps due to increased fracturing and subsequent erosion. Analysis of rose diagrams using a multivariate technique indicated lithology as the primary control for the lower grouping levels. Groupings at higher levels indicated that areas overlying active structures may be isolated from their neighbors by this technique while passive structures showed no differences which could be isolated.

  19. 4D understanding of failures in soft sedimentary rocks using repetitive terrestrial stereo-photogrammetry: the case of the Rosselin deep-seated slope instability, Valais, Switzerland.

    Science.gov (United States)

    Travelletti, Julien; Monnet, Régis

    2014-05-01

    The objective of this study is (i) to highlight the potential of low-cost stereo-photogrammetry to monitor the 4D deformation of rock instabilities and (ii) to add to the 4D understanding of failure development in soft sedimentary rocks. The Rosselin instability is located in a landslides prone area in the municipality of Riddes, canton of Valais, Switzerland. This deep-seated slope instability has developed in Triassic dolomitic carbonates overlaid by highly fractured Cretaceous conglomerates and schists. Its estimated volume is of 300'000 m3. A catastrophic scenario can cause the obstruction of a river located 400 m beneath. The sudden failure of the landslide dam would then threaten the municipality of Riddes of major floods and debris flows. On May 14, 2013, precursor signs of activity (minor rockfalls, developments of tension cracks) in a part of the Rosselin instability were observed after a relatively wet period. Therefore, in complement to risk mitigation planning a monitoring strategy was set up. In addition to the installation of extensometers, repetitive terrestrial stereo-photogrammetry surveys were acquired at a distance of 100 m of the instability in order to build a four-dimensional understanding of the failure. Seventeen high-resolution photogrammetric acquisitions were realized between the 15th and the 17th of May the day the main failure occurred. The comparison of the states before and after the event of May 17 allowed to compute a mobilized volume of 30'000 m3 (1/10 of the total volume of the Rosselin instability). 3D displacements are derived from the photogrammetric acquisition and obtained with a cross-correlation technique. The kinematics analysis allowed the highlighting of (i) strong deformations during the pre-failure stage within the mass probably induced by progressive brittle fracture damages and of (ii) a control of pre-existing regional discontinuities in the failure stage leading to a general wedge sliding. It also shows that in the

  20. Gas-water-rock interactions in Frio Formation following CO2 injection: Implications for the storage of greenhouse gases in sedimentary basins

    Science.gov (United States)

    Kharaka, Yousif K.; Cole, David R.; Hovorka, Susan D.; Gunter, W.D.; Knauss, Kevin G.; Freifeild, Barry M.

    2006-01-01

    To investigate the potential for the geologic storage of CO2 in saline sedimentary aquifers, 1600 t of CO2 were injected at 1500 m depth into a 24-m-thick sandstone section of the Frio Formation, a regional brine and oil reservoir in the U.S. Gulf Coast. Fluid samples obtained from the injection and observation wells before CO2 injection showed a Na-Ca-Cl–type brine with 93,000 mg/L total dissolved solids (TDS) at near saturation with CH4 at reservoir conditions. Following CO2 breakthrough, samples showed sharp drops in pH (6.5–5.7), pronounced increases in alkalinity (100–3000 mg/L as HCO3) and Fe (30–1100 mg/L), and significant shifts in the isotopic compositions of H2O, dissolved inorganic carbon (DIC), and CH4. Geochemical modeling indicates that brine pH would have dropped lower but for the buffering by dissolution of carbonate and iron oxyhydroxides. This rapid dissolution of carbonate and other minerals could ultimately create pathways in the rock seals or well cements for CO2 and brine leakage. Dissolution of minerals, especially iron oxyhydroxides, could mobilize toxic trace metals and, where residual oil or suitable organics are present, the injected CO2 could also mobilize toxic organic compounds. Environmental impacts could be major if large brine volumes with mobilized toxic metals and organics migrated into potable groundwater. The δ18O values for brine and CO2 samples indicate that supercritical CO2 comprises ∼50% of pore-fluid volume ∼6 mo after the end of injection. Postinjection sampling, coupled with geochemical modeling, indicates that the brine gradually will return to its preinjection composition.

  1. NEW PALEOMAGNETIC DATA ON THE SILURIAN AND DEVONIAN SEDIMENTARY ROCKS FROM PODOLIA, SW UKRAINE, AND KINEMATICS OF THE EAST EUROPEAN PLATFORM IN THE MIDDLE PALEOZOIC

    Directory of Open Access Journals (Sweden)

    V. G. Bakhmutov

    2015-09-01

    Full Text Available Paleomagnetic data are the priority source of information for global paleotectonic reconstructions representing horizontal movements of the crustal blocks. Upon receipt of new paleomagnetic data, kinematic models of the East European platform in the Paleozoic are regularly revised and improved. The article presents results of the paleomagnetic study of sedimentary gray-colored and red beds of the Silurian and Lower Devonian sequences located in the Dniester river basin, Podolia region, SW Ukraine. The study covered 17 outcrops that are stratigraphically correlated with the Wenlock, Ludlow, Pridoli states of the Sillurian and the Lochkovian stage of the Devon. Over 400 samples of grey limestone, argillite, dolomite, red limestone and sandstone were analyzed, and two components of natural remnant magnetization (NRM were revealed. The first component with SSW declination and negative inclination is revealed in the majority of the samples during AF- and T-magnetic cleaning. Its pole positions, that are calculated separately for each series, are trending to the Permian segment of the apparent polar wander path (APWP published by Torsvik et al. [2012] for Baltica / Stable Europe. Considering its chemical origin, this NRM component is related to formation of authigenic minerals due to rock remagnetization. The second component is revealed only in some samples taken from the red beds (during thermal demagnetization in the range of unblocking temperatures from 590 to 690 °С and in few samples of grey limestone (in AF fields from 30 to 70 mT or in the range of unblocking temperatures from 300 to 460 °С. This component has SW declination and positive inclination, goes to the origin of coordinates of the diagrams, and has all the indicators of primary magnetization of sediments. Calculated positions of the poles (0 ºS and 329 ºE for grey limestone of the Tiverskaya series, 2.3 °S and 338.4 °E for red beds of the Dniestrovskaya series, etc. are well

  2. NEW PALEOMAGNETIC DATA ON THE SILURIAN AND DEVONIAN SEDIMENTARY ROCKS FROM PODOLIA, SW UKRAINE, AND KINEMATICS OF THE EAST EUROPEAN PLATFORM IN THE MIDDLE PALEOZOIC

    Directory of Open Access Journals (Sweden)

    V. G. Bakhmutov

    2014-01-01

    Full Text Available Paleomagnetic data are the priority source of information for global paleotectonic reconstructions representing horizontal movements of the crustal blocks. Upon receipt of new paleomagnetic data, kinematic models of the East European platform in the Paleozoic are regularly revised and improved. The article presents results of the paleomagnetic study of sedimentary gray-colored and red beds of the Silurian and Lower Devonian sequences located in the Dniester river basin, Podolia region, SW Ukraine. The study covered 17 outcrops that are stratigraphically correlated with the Wenlock, Ludlow, Pridoli states of the Sillurian and the Lochkovian stage of the Devon. Over 400 samples of grey limestone, argillite, dolomite, red limestone and sandstone were analyzed, and two components of natural remnant magnetization (NRM were revealed. The first component with SSW declination and negative inclination is revealed in the majority of the samples during AF- and T-magnetic cleaning. Its pole positions, that are calculated separately for each series, are trending to the Permian segment of the apparent polar wander path (APWP published by Torsvik et al. [2012] for Baltica / Stable Europe. Considering its chemical origin, this NRM component is related to formation of authigenic minerals due to rock remagnetization. The second component is revealed only in some samples taken from the red beds (during thermal demagnetization in the range of unblocking temperatures from 590 to 690 °С and in few samples of grey limestone (in AF fields from 30 to 70 mT or in the range of unblocking temperatures from 300 to 460 °С. This component has SW declination and positive inclination, goes to the origin of coordinates of the diagrams, and has all the indicators of primary magnetization of sediments. Calculated positions of the poles (0 ºS and 329 ºE for grey limestone of the Tiverskaya series, 2.3 °S and 338.4 °E for red beds of the Dniestrovskaya series, etc. are well

  3. High-Temperature, Perhaps Silicic, Volcanism on Mars Evidenced by Tridymite Detection in High-SiO2 Sedimentary Rock at Gale Crater, Mars

    Science.gov (United States)

    Morris, R. V.; Vaniman, D. T.; Blake, D. F.; Gellert, R.; Chipera, S. J.; Rampe, E. B.; Ming, D. W.; Morrison, S. M.; Downs, R. T.; Treiman, A. H.; hide

    2016-01-01

    The Mars Science Laboratory (MSL) rover, Curiosity, has been exploring sedimentary rocks within Gale crater since landing in August, 2012. On the lower slopes of Aeolis Mons (a.k.a. Mount Sharp), drill powder was collected from a high-silica (74 wt% SiO2) outcrop named Buckskin (BK). It was a surprise to find that the Buckskin sample contained significant amounts of the relatively rare silica polymorph tridymite. We describe the setting of the Buckskin sample, the detection of tridymite by the MSL Chemistry and Mineralogy (CheMin) X-ray diffraction instrument, and detection implications. Geologic setting: The Buckskin outcrop is part of the Murray formation exposed in the Marias Pass area. The formation was previously studied by CheMin in the Pahrump Hills member [1] where three samples of drill fines were analyzed (Confidence Hills (CH), Mojave2 (MJ) and Telegraph Peak (TP) [2]). Assuming approximately horizontal bedding, the Buckskin outcrop is approx.15 m stratigraphically above the bottom of the Pahrump Hills member. Mudstone, generally characterized by fine lamination, is the dominant depositional facies [1]. Buckskin Mineralogical and Chemical Composition: The CheMin instrument and XRD pattern analysis procedures have been previously discussed [3-6]. The diffraction pattern used for quantitative XRD analysis (Fig. 1) is the sum of the first 4 of 45 diffraction images. The remaining images are all characterized by both on-ring and off-ring diffraction spots that we attributed to poor grain motion and particle clumping. Coincident with particle clumping was a significant decrease in the intensity of the tridymite diffraction peaks (Fig. 2a). The derived mineralogical composition of the crystalline component (derived from the first 4 diffraction images) is given in Table 1. The tridymite is well-crystalline and its pattern is refined as monoclinic tridymite (Fig 1). Mineral chemical compositions were derived from XRD unit cell parameters or obtained from

  4. Comment on "Depth-discrete specific storage in fractured sedimentary rock using steady-state and transient single-hole hydraulic tests" by Patryk M. Quinn, John A. Cherry, Beth L. Parker, J. Hydrol. 542 (2016) 756-771

    Science.gov (United States)

    Çimen, Mesut

    2017-03-01

    Quinn et al. (2016) presented a method to estimate storativity (S) of fractured sedimentary rock from straddle packer tests after transmissivity (T) of aquifer was determined from low-flow constant-head (CH) step tests. Constant-rate pumping tests were carried out to determine S by using the Cooper and Jacob (1946) approximation. Estimating the aquifer parameters depends on a matching of observation data to theoretical response which is mathematically obtained from a physical model. The results of both constant rate injection and withdrawal tests in the borehole C6zone17 cannot show this simulation. This comment proposes a reasonable procedure to estimate storativity.

  5. Rock Slope Design Criteria

    Science.gov (United States)

    2010-06-01

    Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary : rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, : and siltstones ...

  6. Using detrital zircons from late Permian to Triassic sedimentary rocks in the south-eastern Central Asian Orogenic Belt (NE China) to constrain the timing of the final closure of the Paleo-Asian Ocean

    Science.gov (United States)

    Zhou, Zhong-Biao; Pei, Fu-Ping; Wang, Zhi-Wei; Cao, Hua-Hua; Xu, Wen-Liang; Wang, Zi-Jin; Zhang, Ying

    2017-08-01

    We present new detrital zircon U-Pb-Hf isotope data for seven samples from late Permian to Triassic sedimentary units in Jilin Province, Northeast (NE) China, and use these data to constrain the timing of final closure of the Paleo-Asian Ocean and the late Permian to Triassic tectonic evolution of the Changchun-Yanji suture belt. The late Permian to Early Triassic sedimentary rocks contain material derived from both the northern margin of the North China Craton and the eastern segment of the Central Asian Orogenic Belt, suggesting that final closure of the Paleo-Asian Ocean occurred during the late Permian at latest. Metamorphic zircons within two metasedimentary units record amphibolite-facies retrograde metamorphism and metamorphic recrystallization events at ∼233 Ma, postdating the peak of the collisional event in this area and providing an upper limit for the termination of orogenesis. In comparison, metamorphic zircons with younger ages of ∼223 and ∼210 Ma from Middle-Late Triassic sandstones in eastern Jilin Province provide evidence of later hydrothermal events. These results, combined with the presence of voluminous middle Late Triassic terrestrial sedimentary rocks with bidirectional provenances in this area and coeval A-type granites and rhyolites in adjacent areas, suggest that this region underwent post-orogenic extension after the final closure of the Paleo-Asian Ocean. In brief, we suggest that the final closure of the Paleo-Asian Ocean along the Changchun-Yanji belt occurred during the late Permian at latest and that the associated collisional orogeny terminated at ∼233 Ma (i.e. early Late Triassic). This belt was subsequently dominated by post-collisional extensional setting during the middle Late Triassic.

  7. Geochemistry and geochronology from Cretaceous magmatic and sedimentary rocks at 6°35‧ N, western flank of the Central cordillera (Colombian Andes): Magmatic record of arc growth and collision

    Science.gov (United States)

    Jaramillo, J. S.; Cardona, A.; León, S.; Valencia, V.; Vinasco, C.

    2017-07-01

    The spatio-temporal, compositional and deformational record of magmatic arcs are sensible markers of the long-term evolution of convergent margins including collisional events. In this contribution, field relations, U-Pb LA-ICP-MS zircon geochronology from magmatic and sedimentary rocks, and whole-rock geochemistry from volcanic and plutonic rocks are used to reconstruct the Cretaceous arc growth and collision in the awakening of the Northern Andean orogeny in northwestern Colombia. The Quebradagrande Complex that includes a sequence of volcanic rocks intercalated with quartz-rich sediments is a tholeiitic arc characterized by an enrichment in LREE and Nb-Ti anomalies that document crustal thickening in an arc system that was already active by ca. 93 Ma. This arc was built associated with thin continental and newly formed oceanic crust, as suggested by the presence of Triassic and older detrital zircons in the associated sandstones. This fringing arc subsequently experienced deformation and a major switch to and enriched calc-alkaline high-k plutonism between 70 and 73 Ma. The deformation record and changes in composition are related to an opposite double-vergence Molucca-sea type arc-arc collision that ended with the accretion to the continental margin of an allochthonous island arc built on an oceanic plateau associated with the Caribbean plate. The new time-framework suggest that the Late Cretaceous to Paleocene collisional tectonics include various stages before the switching to a subduction-dominated regime in most of the Cenozoic.

  8. Frictional processes during flank motion at Mount Etna (Italy): experimental characterisation of slip on similar and dissimilar volcanic and sedimentary rocks.

    Science.gov (United States)

    Rozanski, Wojciech; Lavallee, Yan; Kendrick, Jackie; Castagna, Angela; Mitchell, Thomas; Heap, Michael; Vinciguerra, Sergio; Hirose, Takehiro; Dingwell, Donald

    2015-04-01

    The edifice of Mount Etna (Italy) is structurally unstable, exhibiting a near continuous ESE seaward sliding along a set of faults due to interplay between regional tectonics, gravity instability and magma intrusion. Continuous seismic and ground deformation monitoring reveals the resulting large-scale flank motion at variable rates. The mechanisms controlling this faulting kinetic remains, however, poorly constrained. Examination of the fault zones reveals a range of rock types along the different fault segments: fresh and altered basalt, clay and limestone. As lithological contrasts can jeopardise the structural stability of an edifice, we experimentally investigate the frictional properties of these rocks using low- to high-velocity-rotary shear tests on similar and dissimilar rocks to better understand episodes of slow flank motion as well as rapid and catastrophic sector collapse events. The first set of experiments was performed at velocities up to 1.2 m/s and at normal stresses of 1.5 MPa, commensurate with depths of the contacts seen in the Etna edifice. Friction experiments on clay gouge shows the strong rate-weakening dependence of slip in this material as well as the release of carbon dioxide. Friction experiments on solid rocks show a wider range of mechanical behaviour. At high velocity (>0.6 m/s) volcanic rocks tend to melt whereas the clay and limestone do not; rather they decarbonate, which prevents the rock from achieving the temperature required for melting. Experiments on dissimilar rocks clearly show that composition of host rocks affects the composition and viscosity of the resultant frictional melt, which can have a dramatic effect on shear stress leading to fault weakening or strengthening depending on the combination of host rock samples. A series of low- to moderate-slip velocity experiments is now being conducted to complement our dataset and provide a more complete rock friction model applicable to Mount Etna.

  9. Identification of remagnetization processes in Paleozoic sedimentary rocks of the northeast Rhenish Massif in Germany by K-Ar dating and REE tracing of authigenic illite and Fe oxides

    Science.gov (United States)

    Zwing, A.; Clauer, N.; Liewig, N.; Bachtadse, V.

    2009-06-01

    This study combines mineralogical, chemical (rare earth elemental (REE)) and isotopic (K-Ar) data of clay minerals as well as chemical compositions (major and REE) of Fe oxide leachates from remagnetized Palaeozoic sedimentary rocks from NE Rhenish Massif in Germany, for which the causes of remagnetization are not yet clear. The dominant carrier of the syntectonic, pervasive Carboniferous magnetization is magnetite. The Middle Devonian clastic rocks record an illitization event at 348 ± 7 Ma probably connected to a major magmatic event in the Mid-German Crystalline Rise, whereas a second illitization episode at 324 ± 3 Ma is coeval to the northward migrating deformation through the Rhenish Massif, being only detected in Upper Devonian and Lower Carboniferous rocks. The age of that younger illitization is not significantly different from that of the remagnetization, which, however, is not restricted to the upper part of the orogenic belt, but affects also the Middle Devonian strata. The REE patterns of the Fe-enriched leachates support two mineralization episodes with varied oxidation-reduction conditions outlined by varied Eu and Ce anomalies. This is not compatible with a unique, pervasive migration of orogenic fluids on a regional scale to explain the remagnetization in the studied region. While clay diagenesis and remagnetization are time-equivalent in Upper Devonian and Lower Carboniferous rocks, they are not so in Middle Devonian rocks. Transformation of smectite into illite cannot, therefore, account for the growth of associated authigenic magnetite, which must have been triggered by a different process. Since remagnetization and deformation ages are similar, the mechanism could relate to local physical conditions such as pressure solution and changing pore fluid pressure due to tectonic stress as well as to chemical conditions such as changing composition of the pore fluids.

  10. Addition of sedimentary rock to kaolinitic clays: influence on sintering process Adição de rocha sedimentar às argilas cauliníticas: influência no processo de sinterização

    Directory of Open Access Journals (Sweden)

    A. E. Souza

    2013-03-01

    Full Text Available The physical and mechanical properties of clay-based ceramic probes with sedimentary rock added as the non-plastic component were evaluated. Samples were prepared with 0, 20, 40, 60 and 80 wt.% of rock added to the clay material. Pressed (7 ton probes were sintered at 500, 800, 900, 1000, 1100 and 1200 °C and submitted to X-ray diffraction analysis and technological characterization. The X-ray diffraction results showed that the sedimentary rock had micaceous clay minerals, while the clay material had kaolinite as the main phases. Thermal analysis and X-ray diffraction showed reactions that indicated transformation (inversion of quartz, decomposition (loss of hydroxides and phase formation (mullite during heat treatment of the samples. The technological tests showed that the addition of sedimentary rock improved some properties of the sintered material, aided by the presence of fluxes. However, the presence of quartz in the rock hampered the formation of the mullite phase. The formation of new phases and transformations occurring during the heating and cooling of the samples helped explain the technological properties of ceramic materials.Foram avaliadas, durante o processo de sinterização, as propriedades mecânicas de peças cerâmicas a base de argila com adição de rocha sedimentar. Foram preparados corpos de prova com 0, 20, 40, 60 e 80% em peso de rocha adicionada ao material argiloso. As peças foram sinterizadas nas temperaturas de 500, 800, 900, 1000, 1100 e 1200 °C e, posteriormente, submetidas à análise de difração de raios X e a ensaios tecnológicos Os resultados de difração de raios X mostram que a rocha sedimentar apresenta argilominerais micáceos enquanto o material argiloso possui a caulinita como fase principal. Técnicas de análises térmicas e difração de raios X das diferentes misturas mostram reações que indicam transformação (inversão do quartzo, decomposição (perda de hidróxidos e formação de fase

  11. Teaching the Rock Cycle with Ease.

    Science.gov (United States)

    Bereki, Debra

    2000-01-01

    Describes a hands-on lesson for teaching high school students the concept of the rock cycle using sedimentary, metamorphic, and igneous rocks. Students use a rock cycle diagram to identify pairs of rocks. From the rock cycle, students explain on paper how their first rock became the second rock and vice versa. (PVD)

  12. Neoproterozoic diamictite-bearing sedimentary rocks in the northern Yili Block and their constraints on the Precambrian evolution of microcontinents in the Western Central Asian Orogenic Belt

    Science.gov (United States)

    He, Jingwen; Zhu, Wenbin; Zheng, Bihai; Wu, Hailin; Cui, Xiang; Lu, Yuanzhi

    2015-12-01

    The origin and tectonic setting of Precambrian sequences in the Central Asian Orogenic Belt (CAOB) have been debated due to a lack of high resolution geochronological data. Answering this question is essential for the understanding of the tectonic framework and Precambrian evolution of the blocks within the CAOB. Here we reported LA-ICP-MS detrital zircon U-Pb ages and in-situ Hf isotopic data for Neoproterozoic sedimentary cover in the northern Yili Block, an important component of the CAOB, in order to provide information on possible provenance and regional tectonic evolution. A total of 271 concordant U-Pb zircon ages from Neoproterozoic sedimentary cover in the northern Yili Block define three major age populations of 1900-1400 Ma, 1300-1150 Ma and 700-580 Ma, which are quite different from cratons and microcontinents involved in the CAOB. Although it is not completely consistent with the local basement ages, an autochthonous provenance interpretation is more suitable. Some zircon grains show significant old Hf model ages (TDMC; 3.9-2.4 Ga) and reveal continental crust as old as Paleoarchean probably existed. Continuous Mesoproterozoic zircon age populations exhibit large variations in the εHf(t) ratios, suggesting the long-time involvement of both reworked ancient crust and juvenile material. Similar Mesoproterozoic evolution pattern is identified in many continental terranes involved in the CAOB that surround the Tarim Craton. Based on our analysis and published research, we postulate that the northern Yili Block, together with Chinese Central Tianshan, Kyrgyz North Tianshan and some other microcontinents surrounding the Tarim Craton, once constituted the continental margin of the Tarim Craton in the Mesoproterozoic, formed by long-lived accretionary processes. Most of the late Neoproterozoic zircons exhibit significant positive εHf(t) ratios, suggesting the addition of juvenile crust. It is consistent with the tectonic event related to the East Africa

  13. Lead in the Getchell-Turquoise ridge Carlin-type gold deposits from the perspective of potential igneous and sedimentary rock sources in Northern Nevada: Implications for fluid and metal sources

    Science.gov (United States)

    Tosdal, R.M.; Cline, J.S.; Fanning, C.M.; Wooden, J.L.

    2003-01-01

    Lead isotope compositions of bulk mineral samples (fluorite, orpiment, and realgar) determined using conventional techniques and of ore-stage arsenian pyrite using the Sensitive High Resolution Ion-Microprobe (SHRIMP) in the Getchell and Turquoise Ridge Carlin-type gold deposits (Osgood Mountains) require contribution from two different Pb sources. One Pb source dominates the ore stage. It has a limited Pb isotope range characterized by 208Pb/206Pb values of 2.000 to 2.005 and 207Pb/206Pb values of 0.8031 to 0.8075, as recorded by 10-??m-diameter spot SHRIMP analyses of ore-stage arsenian pyrite. These values approximately correspond to 206Pb/204Pb of 19.3 to 19.6, 207Pb/204Pb of 15.65 to 15.75, and 208Pb/204Pb of 39.2 to 39.5. This Pb source is isotopically similar to that in average Neoproterozoic and Cambrian elastic rocks but not to any potential magmatic sources. Whether those clastic rocks provided Pb to the ore fluid cannot be unequivocally proven because their Pb isotope compositions over the same range as in ore-stage arsenian pyrite are similar to those of Ordovician to Devonian siliciclastic and calcareous rocks. The Pb source in the calcareous rocks most likely is largely detrital minerals, since that detritus was derived from the same sources as the detritus in the Neoproterozoic and Cambrian clastic rocks. The second Pb source is characterized by a large range of 206Pb/204Pb values (18-34) with a limited range of 208Pb/204Pb values (38.1-39.5), indicating low but variable Th/U and high and variable U/Pb values. The second Pb source dominates late and postore-stage minerals but is also found in preore sulfide minerals. These Pb isotope characteristics typify Ordovician to Devonian siliciclastic and calcareous rocks around the Carlin trend in northeast Nevada. Petrologically similar rocks host the Getchell and Turquoise Ridge deposits. Lead from the second source was either contributed from the host sedimentary rock sequences or brought into the

  14. Nd isotopic and geochemical constraints on the provenance and tectonic setting of the low-grade meta-sedimentary rocks from the Trans-North China Orogen, North China Craton

    Science.gov (United States)

    Liu, Chaohui; Zhao, Guochun; Liu, Fulai; Han, Yigui

    2014-11-01

    In the Trans-North China Orogen (TNCO) of the North China Craton, low-grade supracrustal successions extensively occur in the Wutai, Lüliang, Zanhuang, Zhongtiao and Dengfeng Complexes from north to south. Meta-sedimentary samples from the Wutai and Zhongtiao Complexes were collected for geochemical and Nd isotopic studies and several samples from the Zanhuang and Dengfeng Complexes were also analyzed for Nd isotopic studies for comparative purpose. Most of the meta-siltstones and meta-sandstones from the Wutai and Zhongtiao Complexes are characterized by depletions in mobile elements like CaO, Sr and Na2O, high Chemical Index of Weathering (CIW) values and strong positive correlation between Al2O3 and TiO2, indicating intense weathering conditions. Significant post-depositional K-metasomatism is indicated in the A-CN-K diagrams for most of the analyzed samples and the relatively high pre-metasomatized Chemical Index of Alteration (CIA) values (43-87) also imply a high degree of source weathering. Depleted transitional trace elements (Ni, Cr, Co and Sc), fractionated light rare earth elements patterns, mild negative Eu anomalies in the majority of these meta-sedimentary samples point toward felsic source rocks, including the ∼2.5 Ga granitics, TTG gneisses and the Paleoproterozoic granitics in the TNCO. Minor contribution from mafic rocks is evidenced from relative high contents of MgO, Fe2O3T, Sc and lower La/YbN ratios in some older sequence-set samples from the Zhongtiao Complex. Our geochemical and Nd isotopic data, combined with previous studies in the lithostratigraphic sequence, provenance and depositional age, suggest that the older and younger sequence-sets of the low-grade supracrustal successions in the TNCO were deposited in the different depositional environments. The older sequence-set was deposited in a back-arc basin between the “Andean-type” continental margin arc and the Eastern Block after ∼2.1 Ga, whereas the younger sequence-set formed

  15. Evolved gas analyses of sedimentary rocks and eolian sediment in Gale Crater, Mars: Results of the Curiosity rover's sample analysis at Mars instrument from Yellowknife Bay to the Namib Dune

    Science.gov (United States)

    Sutter, B.; McAdam, A. C.; Mahaffy, P. R.; Ming, D. W.; Edgett, K. S.; Rampe, E. B.; Eigenbrode, J. L.; Franz, H. B.; Freissinet, C.; Grotzinger, J. P.; Steele, A.; House, C. H.; Archer, P. D.; Malespin, C. A.; Navarro-González, R.; Stern, J. C.; Bell, J. F.; Calef, F. J.; Gellert, R.; Glavin, D. P.; Thompson, L. M.; Yen, A. S.

    2017-12-01

    The sample analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, H2, SO2, H2S, NO, CO2, CO, O2, and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater, Mars. These evolved gas detections indicate nitrates, organics, oxychlorine phase, and sulfates are widespread with phyllosilicates and carbonates occurring in select Gale Crater materials. Coevolved CO2 (160 ± 248-2373 ± 820 μgC(CO2)/g) and CO (11 ± 3-320 ± 130 μgC(CO)/g) suggest that organic C is present in Gale Crater materials. Five samples evolved CO2 at temperatures consistent with carbonate (0.32 ± 0.05-0.70 ± 0.1 wt % CO3). Evolved NO amounts to 0.002 ± 0.007-0.06 ± 0.03 wt % NO3. Evolution of O2 suggests that oxychlorine phases (chlorate/perchlorate) (0.05 ± 0.025-1.05 ± 0.44 wt % ClO4) are present, while SO2 evolution indicates the presence of crystalline and/or poorly crystalline Fe and Mg sulfate and possibly sulfide. Evolved H2O (0.9 ± 0.3-2.5 ± 1.6 wt % H2O) is consistent with the presence of adsorbed water, hydrated salts, interlayer/structural water from phyllosilicates, and possible inclusion water in mineral/amorphous phases. Evolved H2 and H2S suggest that reduced phases occur despite the presence of oxidized phases (nitrate, oxychlorine, sulfate, and carbonate). SAM results coupled with CheMin mineralogical and Alpha-Particle X-ray Spectrometer elemental analyses indicate that Gale Crater sedimentary rocks have experienced a complex authigenetic/diagenetic history involving fluids with varying pH, redox, and salt composition. The inferred geochemical conditions were favorable for microbial habitability and if life ever existed, there was likely sufficient organic C to support a small microbial population.

  16. Apport des expériences de mécaniques des roches à la géologie structurale des bassins sédimentaires Contribution of Rock-Mechanics Experiments to the Stuctural Geology of Sedimentary Basins

    Directory of Open Access Journals (Sweden)

    Poulet M.

    2006-11-01

    specify the area where rock-mechanics experiments con be applied to structural geology, this article begins by defining the ordres of magnitude of the different factors in nature that control stress/strain relations i, e. the stresses involaed, rate of strain, temperature and anisotropy of rock. A review is then made of laborofory test results of the uniaxial type (surface conditions and then of the triaxial type (deep conditions, with the nature of the stresses involved being specified in each case, i.e. tension, compression and/or shear. Rock behavior during compression tests enables them to be classified in three categories : so-called elastic rocks (compact sedimentary, metamorphic and crystalline rocks, so-called elasto-plastic rocks with some porosity (sandstone, iimestone, so called plastic rocks (salt, gypsum. With each type thus defined, laboratory experiments are performed ta analyze the influence of the following parameters : confining pressure which increases with depth and makes for considérable permanent...

  17. Metallogeny of Mesoproterozoic Sedimentary Rocks in Idaho and Montana - Studies by the Mineral Resources Program, U.S. Geological Survey, 2004-2007

    Science.gov (United States)

    O'Neill, J. Michael

    2007-01-01

    Preface By J.Michael O'Neill The major emphasis of this project was to extend and refine the known Mesoproterozoic geologic and metallogenic framework of the region along and adjacent to the Idaho-Montana boundary north of the Snake River Plain. The Mesoproterozoic metasedimentary rocks in this part of east-central Idaho host important Cu-Co-Au stratabound mineral resources as well as younger, epigenetic hydrothermal, sulfide base-metal mineral deposits. Two tasks of this study were to more accurately understand and portray the character and origin of cobalt-copper-gold deposits that compose the Idaho cobalt belt and specifically to analyze ore mineralogy and metallogenesis within the Blackbird mining district in the central part of the belt. Inasmuch as the cobalt belt is confined to the Mesoproterozoic Lemhi Group strata of east-central Idaho, geologic investigations were also undertaken to determine the relationship between strata of the Lemhi Group and the more extensive, noncobalt-bearing, Belt-Purcell Supergroup strata to the north and northwest. Abrupt lateral differences in the character and thickness of stratigraphic units in the Mesoproterozoic Lemhi Basin may indicate differential sedimentation in contemporaneous fault-bounded subbasins. It is suggested that northeast-trending basement faults of the Great Falls tectonic zone controlled development of the subbasins. O'Neill and others (chapter A, this volume) document a second major basement fault in this area, the newly recognized northwest-striking Great Divide megashear, a zone 1-2 km wide of left-lateral strike-slip faults active during Mesoproterozoic sedimentation and bounding the Cu-Co belt on the northwest. The megashear is a crustal-scale tectonic feature that separates Lemhi Group strata from roughly coeval Belt-Purcell strata to the north and northwest in Montana and northern Idaho. The results of numerous geologic investigations of the Cu- and Co-bearing Mesoproterozoic rocks of east

  18. Hypothetical Insurance and Higher Education

    Science.gov (United States)

    Colburn, Ben; Lazenby, Hugh

    2016-01-01

    What level of government subsidy of higher education is justified, in what form, and for what reasons? We answer these questions by applying the hypothetical insurance approach, originally developed by Ronald Dworkin in his work on distributive justice. On this approach, when asking how to fund and deliver public services in a particular domain,…

  19. A sedimentary tetrahydrophenanthrene derivative of tetrahymano

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Koster, J.; Baas, M.; Ossebaar, J.; Dekker, M.; Pool, W.; Geenevasen, J.A.J.

    1999-01-01

    A novel tetrahydrophenanthrene derivative 1 (1,1,7,8-tetramethyl-1,2,3,4-tetrahydrophenanthrene), formed from the triterpenoid tetrahymanol 2a by dehydration, ring A and B degradation and aromatisation during sediment diagenesis, has been isolated from a 180 Ma old marine sedimentary rock and

  20. Rock Slope Design Criteria : Executive Summary Report

    Science.gov (United States)

    2010-06-01

    Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, and siltstones that...

  1. Uranium favorability of tertiary sedimentary rocks of the western Okanogan highlands and of the upper Columbia River valley, Washington. [Measurement and sampling of surface sections, collection of samples from isolated outcrops, and chemical and mineralogical analyses of samples; no known uranium deposits

    Energy Technology Data Exchange (ETDEWEB)

    Marjaniemi, D.K.; Robins, J.W.

    1975-08-01

    Tertiary sedimentary rocks in the northern portions of the western Okanogan highlands and in the upper Columbia River valley were investigated during a regional study to determine the favorability for potential uranium resources of the Tertiary sedimentary rocks of northeastern Washington. This project involved measurement and sampling of surface sections, collection of samples from isolated outcrops, and chemical and mineralogical analyses of samples. No portion of the project area of this report is rated of high or of medium favorability for potential uranium resources. Low favorability ratings are given to Oroville, Tonasket, and Pine Creek areas of the Okanogan River valley; to the Republic graben; and to the William Lakes, Colville, and Sheep Creek areas of the upper Columbia River valley. All these areas contain some fluvial, poorly sorted feldspathic or arkosic sandstones and conglomerates. These rocks are characterized by very low permeability and a consistently high siliceous matrix suggesting very low initial permeability. There are no known uranium deposits in any of these areas, and low level uranium anomalies are rare.

  2. Stochastic Representation of Sedimentary Geology

    Science.gov (United States)

    Elmouttie, M. K.; Krähenbühl, G.; Poropat, G. V.; Kelso, I.

    2014-03-01

    Discrete fracture network representations of discontinuities in rock masses have been shown to be useful in capturing heterogeneity in rock mass properties. Providing computational efficiency in the resulting simulations and analyses is attained, these fracture representations can be combined with structural modelling and sampling algorithms. Multiple fracture network realisations can be generated and the resulting rock mass properties interrogated. Statistical analyses based on fracture connectivity, block size distribution and slope stability can be performed and provide results defined in terms of confidence intervals. For sedimentary geology consisting of dense bedding, equivalent medium continuum methods have traditionally been used in preference to discrete fracture representations due to the large numbers of structures involved and resulting computational complexity. In this paper, it is shown that stochastic representation of these layers can be employed. An analytical solution to accommodate bedding given an assumed block size distribution has been derived. Using this formulation, polyhedral modelling has been used to investigate the influence of bedding on block formation and block size distributions using field data. It is shown that the analysis is both computationally efficient and can capture truncation of size distribution by such layers without numerical methods.

  3. Rockin' around the Rock Cycle

    Science.gov (United States)

    Frack, Susan; Blanchard, Scott Alan

    2005-01-01

    In this activity students will simulate how sedimentary rocks can be changed into metamorphic rocks by intense pressure. The materials needed are two small pieces of white bread, one piece of wheat bread, and one piece of a dark bread (such as pumpernickel or dark rye) per student, two pieces of waxed paper, scissors, a ruler, and heavy books.…

  4. Provenance of zircon of the lowermost sedimentary cover, Estonia, East-European Craton

    Directory of Open Access Journals (Sweden)

    Konsa, M.

    1999-12-01

    Full Text Available Bulk and accessory mineral composition of fresh and weathered crystalline rocks, and sedimentary deposits overlying the crystalline-sedimentary unconformity have been examined in core samples from 28 drill holes in Estonia. Before the Late Vendian to Early Cambrian regional subsidence and sedimentation, the region represented a flat plateau within the Svecofennian Domain. Palaeo-and Mesoproterozoic crystalline rocks, regardless their different initial mineral composition, subcrop under the Upper Vendian/Lower Cambrian sedimentary cover as usually intensely weathered rocks (saprolites composed of residual quartz, altered micas and prevailing clay minerals mainly of the kaolinite group. Thus, the bulk mineral composition of any basement crystalline rocks imparts no specific inherited rock-forming minerals into the covering sedimentary rocks. From the variety of accessory and opaque minerals of crystalline rocks, only zircon populations survived in saprolites. Crystalline rocks of different origin yield different zircons. Relationships between the zircon typology of the basement rocks having specific areas of distribution and the sedimentary rocks immediately overlying those crystalline rocks were the main subject of this study. The result is that siliciclastic sedimentary rocks covering weathered crystalline rocks only in places inherited zircons with typological features characteristic of specific basement areas. In northeastern Estonia, local lenses of the Oru Member (the earliest Upper Vendian sedimentary rocks in Estonia resembling the debris of weathered crystalline rocks yield accessory zircon which in a 1-2 m thick layer above the basement surface is similar to the zircons of the underlying weathering mantle of certain crystalline rocks. In the next unit, the Moldova Member, up to 43 m above the basement surface, a mixture of zircons resembling those of various local basement rocks has been found. Further upwards, in the Vendian and Lower

  5. NATURAL GAS RESOURCES IN DEEP SEDIMENTARY BASINS

    Energy Technology Data Exchange (ETDEWEB)

    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

  6. Sedimentary Petrology: from Sorby to the globalization of Sedimentary Geology; La Petrologia Sedimentaria: desde Sorby a la globalizacion de la Geologia Sedimentaria

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Zarza, A. M.

    2013-02-01

    We describe here the most important milestones and contributions to Sedimentary Petrology compared to other geological disciplines. We define the main aim of our study and the scientific and economic interests involved in Sedimentary Petrology. The body of the paper focuses upon the historical development of this discipline from Henry Sorby's initial work until the present day. The major milestones in its history include: 1) initial descriptive works; 2) experimental studies; 3) the establishment of the different classifications of sedimentary rocks; 4) studies into facies and sedimentary environments; 5) advances in the study of diagenetic processes and their role in hydrocarbon prospection; and 6) the development of Sedimentary Geochemistry. Relationships and coincidences with Sedimentology are discussed. We go on to look at the advances that have taken place over the last 30 years, in which the study of sedimentary rocks is necessarily included in the wider field of Sedimentary Geology as a logical result of the proposal of global models of a changing Earth in which Sedimentary Geology plays a significant part. Finally we mention the notable contributions of Spanish sedimentary petrologists to this whole field of science. (Author) 120 refs.

  7. Reducing hypothetical bias in choice experiments

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Olsen, Søren Bøye; Nielsen, Rasmus Christian Fejer

    eliminate some of the hypothetical bias. The present paper tests an addition to Cheap Talk, an Opt-Out Reminder. The Opt-Out Reminder is an objective short script presented prior to the choice sets, prompting the respondent to choose the opt-out alternative, if he/she finds the proposed policy generated...... alternatives in a choice set too expensive. The results suggest that adding an Opt-Out Reminder to Cheap Talk can in fact reduce hypothetical bias even further and reduces some of the ineffectiveness of CT in relation to the survey bid range and experienced respondents....

  8. White Rock

    Science.gov (United States)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can

  9. Layered Rocks in Ritchey

    Science.gov (United States)

    2004-01-01

    14 May 2004 This March 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light- and dark-toned layered rock outcrops on the floor of Ritchey Crater, located near 28.9oS, 50.8oW. Some or all of these rocks may be sedimentary in origin. Erosion has left a couple of buttes standing on a more erosion-resistant plain. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.

  10. Expression analysis and characteristics of hypothetical protein ...

    African Journals Online (AJOL)

    W Zhang, H Lan, T Wu, C Jiang, Z Lv, Z Nie, X Wu, Y Zhang. Abstract. We cloned a cDNA from silkworm pupal cDNA library and found that, it encodes LOC778500 protein (a “hypothetical protein” in the National Center for Biotechnology Information (NCBI) database). Thus, we named it BmLOC778500 (Bombyx mori ...

  11. South American sedimentary basins

    Energy Technology Data Exchange (ETDEWEB)

    Urien, C.M.

    1984-04-01

    More than 64 sedimentary basins have been identified on the South American continent. According to their regional structural character and tectonic setting, they are classified in 4 super groups. About 20 interior or intracratonic basins occur on South American cratons (Guayanas, Brazilian, and Patagonian). In most cases, their sedimentary fill is Paleozoic or early Mesozoic. Rift or transverse grabens resulting from incipient sea floor spreading extend towards the continental margin. Seventeen basins are located along the Atlantic stable margin, and consist primarily of half grabens with downfaulted seaward blocks. These rifts (or pull-apart basins) were separated as results of the migration of the African and American continental blocks. Therefore the sedimentation is chiefly Cretaceous and Tertiary. On the western edge of South American cratons, almost 20 basins of downwarped blocks extend from Orinoco down to the Malvinas plateau in a relatively uninterrupted chain of retroarc basins, bordered by the Andean orogen. They lie on a flexured Precambrian and Paleozoic basement, and are highly deformed in the west (Subandean belt) due to the action of compressional forces caused by the tectonic influence of the Mesozoic Andean batholith. Westward, the Pacific margin is bordered by 27 foreland and forearc basins, which alternate from north to south on an unstable or quasistable margin, fringed by a trench and slope complex where the ocean crust is subducted beneath the continental plate.

  12. Hydrogeology of sedimentary basins

    Science.gov (United States)

    Kreitler, Charles W.

    1989-03-01

    Hydrogeologic environments in sedimentary basins are as variable as are the different types of basins. Important hydrologic characteristics can be used to distinguish the different types of basin: (1) the topographic setting as determined by the geologic and structural history of the basin; (2) permeability distribution within the basin; and (3) potential energy distributions and flow mechanisms. These parameters control residence times of waters, rates and directions of saline groundwater flow and the origin and chemical composition of the saline waters. The Gulf Coast and Palo Duro Basins, Texas, exemplify two end member types of sedimentary basins. The Gulf Coast Basin is a relatively young, Tertiary-age basin which is presently compacting; fluid movement is from the overpressured, undercompacted sediments up the structural dip or up fault zones into the hydrostatic section, natural fluid pressures are either hydrostatic or overpressured. The Palo Duro is an older, Paleozoic-age basin that has been tectonically uplifted. Fluid flow is gravity driven from topographically high recharge areas to discharge in topographically low areas. Fluid pressures are subhydrostatic. Fluids discharge more easily than they are recharged. Not all flow is derived by a simple recharge discharge model. Brines may flow from other basins into the Palo Duro Basin and waters may discharge from the Palo Duro Basin into other basins. Areal differences in the chemical composition of the basin brines may be the result of different origins.

  13. Mid-Late Triassic metamorphic event for Changhai meta-sedimentary rocks from the SE Jiao-Liao-Ji Belt, North China Craton: Evidence from monazite U-Th-Pb and muscovite Ar-Ar dating

    Science.gov (United States)

    Liu, Fulai; Wang, Fang; Liou, J. G.; Meng, En; Liu, Jianhui; Yang, Hong; Xiao, Lingling; Cai, Jia; Shi, Jianrong

    2014-11-01

    The precise constraints on the timing of metamorphism of the Changhai metamorphic complex is of great importance considering the prolonged controversial issue of the north margin and the extension of the Sulu-Dabie HP-UHP Belt. While the monazite U-Th-Pb and muscovite 40Ar/39Ar techniques are widely accepted as two of the most powerful dating tools for revealing the thermal histories of medium-low grade metamorphic rocks and precisely constraining the timing of metamorphism. The Changhai metamorphic complex at the SE Jiao-Liao-Ji Belt, North China Craton consists of a variety of pelitic schist and Grt-Ky-bearing paragneiss, and minor quartzite and marble. Analyses of mineral inclusions and back-scattered electric (BSE) images of monazites, combined with LA-ICP-MS U-Th-Pb ages for monazites and 40Ar/39Ar ages for muscovites, provide evidence of the origin and metamorphic age of the Changhai metamorphic complex. Monazites separates from various Grt-Mus schists and Grt-Ky-St-Mus paragneisses exhibit homogeneous BSE images from cores to rims, and contain inclusion assemblages of Grt + Mus + Qtz ± Ctd ± Ky in schist, and Grt + Ky + St + Mus + Pl + Kfs + Qtz inclusions in paragneiss. These inclusion assemblages are very similar to matrix minerals of host rocks, indicating they are metamorphic rather than inherited or detrital in origin. LA-ICP-MS U-Th-Pb dating reveals that monazites of schist and paragneiss have consistent 206Pb/238U ages ranging from 228.1 ± 3.8 to 218.2 ± 3.7 Ma. In contrast, muscovites from various schists show slightly older 40Ar/39Ar plateau ages of 236.1 ± 1.5 to 230.2 ± 1.2 Ma. These geochronological and petrological data conclude that the pelitic sediments have experienced a metamorphic event at the Mid-Late Triassic (236.1-218.2 Ma) rather than the Paleoproterozoic (1950-1850 Ma), commonly regarded as the Precambrian basement for the Jiao-Liao-Ji Belt. Hence, the Changhai metamorphic complex should be considered as a discrete

  14. Sedimentary Geology Context and Challenges for Cyberinfrastructure Data Management

    Science.gov (United States)

    Chan, M. A.; Budd, D. A.

    2014-12-01

    A cyberinfrastructure data management system for sedimentary geology is crucial to multiple facets of interdisciplinary Earth science research, as sedimentary systems form the deep-time framework for many geoscience communities. The breadth and depth of the sedimentary field spans research on the processes that form, shape and affect the Earth's sedimentary crust and distribute resources such as hydrocarbons, coal, and water. The sedimentary record is used by Earth scientists to explore questions such as the continental crust evolution, dynamics of Earth's past climates and oceans, evolution of the biosphere, and the human interface with Earth surface processes. Major challenges to a data management system for sedimentary geology are the volume and diversity of field, analytical, and experimental data, along with many types of physical objects. Objects include rock samples, biological specimens, cores, and photographs. Field data runs the gamut from discrete location and spatial orientation to vertical records of bed thickness, textures, color, sedimentary structures, and grain types. Ex situ information can include geochemistry, mineralogy, petrophysics, chronologic, and paleobiologic data. All data types cover multiple order-of-magnitude scales, often requiring correlation of the multiple scales with varying degrees of resolution. The stratigraphic framework needs dimensional context with locality, time, space, and depth relationships. A significant challenge is that physical objects represent discrete values at specific points, but measured stratigraphic sections are continuous. In many cases, field data is not easily quantified, and determining uncertainty can be difficult. Despite many possible hurdles, the sedimentary community is anxious to embrace geoinformatic resources that can provide better tools to integrate the many data types, create better search capabilities, and equip our communities to conduct high-impact science at unprecedented levels.

  15. Observations sur les microfaciès des roches sédimentaires prélevées sur la marge armoricaine Observations on the Microfacies of Sedimentary Rock Samples from the Armorican Margin

    Directory of Open Access Journals (Sweden)

    Pastouret L.

    2006-11-01

    Full Text Available L'étude des dragages de roches et de sédiments effectués sur la marge armoricaine entre 47 et 48, de latitude Nord permet d'en préciser l'évolution paléogéographique et tectonique et de l'intégrer à celle du golfe de Gascogne. L'analyse de mi crofaciès des échantillons rocheux dont l'âge varie du Jurassique supérieur au Néogène met en évidence - d'une part, l'appartenance de la bordure nord de la marge armoricaine au domaine mésogéen au moins jusqu'au Crétacé moyen; - d'autre part, la permanence d'un régime de plate-forme carbonatée qui paraît fonctionner du Tithonique au Tertiaire inférieur, sur laquelle ont pu s'installer des édifices récifaux notamment au Crétacé moyen. Pendant toute cette période la sédimentation a compensé la subsidence; - enfin, l'accentuation de la subsidence à partir de l'Éocène (accompagnée d'une diminution de la production de calcium $ qui est vraisemblablement en relation avec les phénomènes tectoniques majeurs qui ont affecté à ce moment la bordure sud de la plaque européenne. A study of rock samples and sedimenis obtained by dredging from the Armorican Margin (47 ta 48° N brings new data on the paleogeographic and tectonic evolution of this ares in relation ta the formation of the Bay of Biscay. Microfacies ranging from the Upper Jurassic ta the Neogene show - the Armorican Margin until al least the Middle Cretaceous belongs to the Mesogean realm ; - carbonate platform regime prevails from the Tithonian to the Lower Tertiory with reef building occurring in the Middle Cretaceous. During this whole period in the area under consideration, sedimentation accounts for or even exceeds subsidence ; - the subsidence rate increases (and/or carbonate production decreases toward the end of the Eocene, and this may be related ta first order tectonic events offecting the southern part of the European plate.

  16. Petrology and geotechnic setting of the basement comple rocks ...

    African Journals Online (AJOL)

    Mineral constituents and major element oxide data indicate that the gneisses are meta-sedimentary rocks derived from the metamorphism of pelites, whereas the amphibolite are meta-igneous rocks derived from a basic rock of subalkaline affinity. The banded gneisses possess NNW-SSE foliation trends, which are typical of ...

  17. Communication: Hypothetical ultralow-density ice polymorphs

    Science.gov (United States)

    Matsui, Takahiro; Hirata, Masanori; Yagasaki, Takuma; Matsumoto, Masakazu; Tanaka, Hideki

    2017-09-01

    More than 300 kinds of porous ice structures derived from zeolite frameworks and space fullerenes are examined using classical molecular dynamics simulations. It is found that a hypothetical zeolitic ice phase is less dense and more stable than the sparse ice structures reported by Huang et al. [Chem. Phys. Lett. 671, 186 (2017)]. In association with the zeolitic ice structure, even less dense structures, "aeroices," are proposed. It is found that aeroices are the most stable solid phases of water near the absolute zero temperature under negative pressure.

  18. Signs of hypothetical fauna of Venus

    Directory of Open Access Journals (Sweden)

    Ksanfomality Leonid V.

    2014-04-01

    Full Text Available On March 1 and 5, 1982, experiments in television photography instrumented by the landers VENERA-13 and -14, yielded 37 panoramas (or their fragments of the Venus surface at the landing site. Over the past 31 years, no similar missions have been sent to Venus. Using a modern technique the VENERA panoramas were re-examined. A new analysis of Venusian surface panoramas’ details has been made. A few relatively large objects of hypothetical fauna of Venus were found with size ranging from a decimeter to half meter and with unusual morphology. Treated once again VENERA-14 panoramic images revealed ‘amisada’ object about 15 cm in size possessing apparent terramorphic features. The amisada’s body stands out with its lizard-like shape against the stone plates close by. The amisada can be included into the list of the most significant findings of the hypothetical Venusian fauna. The amisada’s body show slow movements, which is another evidence of the Venusian fauna’s very slow style of activity, which appears to be associated with its energy constraints or, and that is more likely, with the properties of its internal medium. The terramorphic features of the Venusian fauna, if they are confirmed, may point out at outstandingly important and yet undiscovered general laws of the animated nature on different planets.

  19. Remagnetization of carbonate rocks in southern Tibet : Perspectives from rock magnetic and petrographic investigations

    NARCIS (Netherlands)

    Huang, Wentao; Lippert, Peter C.; Zhang, Yang; Jackson, Michael J.; Dekkers, Mark J.; Li, Juan; Hu, Xiumian; Zhang, Bo; Guo, Zhaojie; van Hinsbergen, Douwe J.J.

    The latitudinal motion of the Tibetan Himalaya—the northernmost continental unit of the Indian plate—is a key component in testing paleogeographic reconstructions of the Indian plate before the India-Asia collision. Paleomagnetic studies of sedimentary rocks (mostly carbonate rocks) from the Tibetan

  20. Lexical exponents of hypothetical modality in Polish and Lithuanian

    OpenAIRE

    Roman Roszko

    2015-01-01

    Lexical exponents of hypothetical modality in Polish and Lithuanian The article focuses on the lexical exponents of hypothetical modality in Polish and Lithuanian. The purpose for comparing and contrasting the lexical exponents of hypothetical modality is not only to identify all the lexemes in both languages but also find the answer to the following question: whether the morphological exponents of hypothetical modality (so-called modus relativus) familiar to the Lithuanian language have/...

  1. In-situ Detection of Squalane in Sedimentary Organic Matter Using Monoclonal Antibodies

    Science.gov (United States)

    Bailey, J. V.; Corsetti, F. A.; Moldowan, J. M.; Fago, F.; Caron, D.

    2008-12-01

    Sedimentary geolipids can serve as powerful tools for reconstructing ancient ecosystems, but only if investigators can demonstrate that the hydrocarbons are indigenous to their host rocks. The association of molecules with primary sedimentary fabrics could indicate a syngenetic relationship. However, traditional biomarker analyses require extraction from large quantities of powdered rock, confounding detailed spatial correlations. Biological studies commonly use antibodies as extremely sensitive molecular probes. When coupled with fluorescent labels, antibodies allow for the visual localization of molecules. Here we show that monoclonal antibodies that bind specifically to geolipid compounds can be used for in situ detection and labeling of such compounds in mineral-bound organic macerals. Monoclonal antibodies to squalene, produced for human health studies, also react with the geolipid, squalane. We show that squalene antibodies do not react with other common sedimentary hydrocarbons. We also show that squalane antibodies bind specifically to isolated organic-rich lamina in Eocene-age, squalane-containing rocks. These results suggest that squalane is confined to discrete organo-sedimentary fabrics within those rocks, providing evidence for its syngeneity. The chemical similarity of squalane to other sedimentary hydrocarbons hints at the potential for developing monoclonal antibodies to a variety of biomarkers that could then be localized in rocks, sediments, and extant cells.

  2. Testing QCD with Hypothetical Tau Leptons

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.

    1998-10-21

    We construct new tests of perturbative QCD by considering a hypothetical {tau} lepton of arbitrary mass, which decays hadronically through the electromagnetic current. We can explicitly compute its hadronic width ratio directly as an integral over the e{sup +}e{sup -} annihilation cross section ratio, R{sub e{sup +}e{sup -}}. Furthermore, we can design a set of commensurate scale relations and perturbative QCD tests by varying the weight function away from the form associated with the V-A decay of the physical {tau}. This method allows the wide range of the R{sub e{sup +}e{sup -}} data to be used as a probe of perturbative QCD.

  3. Hypothetical conflict situations with friends and peers

    Directory of Open Access Journals (Sweden)

    Petrović Danijela S.

    2012-01-01

    Full Text Available This paper deals with age and sex differences in preferred strategies of conflict resolution in friendship and peer relationships. The study was conducted on the sample of 286 adolescents. Conflict resolution strategies have been investigated by the method of hypothetical conflict situations. For the purposes of this research, we have created an instrument consisting of 20 hypothetical situations, with the following subjects of conflict: breaking the agreement, non-compliance with opinion differences, provocations, dishonesty and stubbornness. Conflict resolution strategies we examined were giving in, withdrawal, competition and problem solving. The results have shown that problem solving is the dominant strategy of adolescents in conflict with friends, while in peer conflicts they more often opt for competition. Age differences are reflected in the fact that older adolescents are more likely to choose problem solving than younger, whereas younger adolescents are more likely to choose a retreat (withdrawal strategy than older. Girls are more prone to choosing problem solving than boys, who, on the other hand, tend to withdraw more than girls. Also, gender of the other person in the conflict is proved to be important - in conflict with male peers, adolescents choose competition to a greater extent and withdraw to a minor extent, compared to when they are in conflict with female peers. The results have practical implications as well. In programs for teaching constructive conflict resolution that are designed for younger adolescents there should be more emphasis on empowerment and training for assertive behaviour. In addition, when teaching about constructive conflict resolution strategies, it is important to consider the gender of adolescents as well as the gender of the person with whom they are in conflict.

  4. Continental growth seen through the sedimentary record

    Science.gov (United States)

    Dhuime, Bruno; Hawkesworth, Chris J.; Delavault, Hélène; Cawood, Peter A.

    2017-07-01

    Sedimentary rocks and detrital minerals sample large areas of the continental crust, and they are increasingly seen as a reliable archive for its global evolution. This study presents two approaches to model the growth of the continental crust through the sedimentary archive. The first builds on the variations in U-Pb, Hf and O isotopes in global databases of detrital zircons. We show that uncertainty in the Hf isotope composition of the mantle reservoir from which new crust separated, in the 176Lu/177Hf ratio of that new crust, and in the contribution in the databases of zircons that experienced ancient Pb loss(es), adds some uncertainty to the individual Hf model ages, but not to the overall shape of the calculated continental growth curves. The second approach is based on the variation of Nd isotopes in 645 worldwide fine-grained continental sedimentary rocks with different deposition ages, which requires a correction of the bias induced by preferential erosion of younger rocks through an erosion parameter referred to as K. This dimensionless parameter relates the proportions of younger to older source rocks in the sediment, to the proportions of younger to older source rocks present in the crust from which the sediment was derived. We suggest that a Hadean/Archaean value of K = 1 (i.e., no preferential erosion), and that post-Archaean values of K = 4-6, may be reasonable for the global Earth system. Models built on the detrital zircon and the fine-grained sediment records independently suggest that at least 65% of the present volume of continental crust was established by 3 Ga. The continental crust has been generated continuously, but with a marked decrease in the growth rate at 3 Ga. The period from > 4 Ga to 3 Ga is characterised by relatively high net rates of continental growth (2.9-3.4 km3 yr- 1 on average), which are similar to the rates at which new crust is generated (and destroyed) at the present time. Net growth rates are much lower since 3 Ga (0

  5. Sedimentary Geothermal Feasibility Study: October 2016

    Energy Technology Data Exchange (ETDEWEB)

    Augustine, Chad [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zerpa, Luis [Colorado School of Mines, Golden, CO (United States)

    2017-01-01

    The objective of this project is to analyze the feasibility of commercial geothermal projects using numerical reservoir simulation, considering a sedimentary reservoir with low permeability that requires productivity enhancement. A commercial thermal reservoir simulator (STARS, from Computer Modeling Group, CMG) is used in this work for numerical modeling. In the first stage of this project (FY14), a hypothetical numerical reservoir model was developed, and validated against an analytical solution. The following model parameters were considered to obtain an acceptable match between the numerical and analytical solutions: grid block size, time step and reservoir areal dimensions; the latter related to boundary effects on the numerical solution. Systematic model runs showed that insufficient grid sizing generates numerical dispersion that causes the numerical model to underestimate the thermal breakthrough time compared to the analytic model. As grid sizing is decreased, the model results converge on a solution. Likewise, insufficient reservoir model area introduces boundary effects in the numerical solution that cause the model results to differ from the analytical solution.

  6. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  7. Organics, Isotopes, and Volatiles in Gale Crater Sedimentary Rocks

    Science.gov (United States)

    Mahaffy, P. R.

    2016-12-01

    Solid samples analyzed by the Curiosity rover on the long traverse from the Gale crater floor to the flanks of Mt. Sharp spread a range of environments from fluvial to lacustrine to eolian, and span 100 m of stratigraphic thickness. The diverse chemical and isotopic composition of organic compounds and inorganic volatiles revealed in these samples analyzed over a period of more than 2 Mars years is described with an emphasis on the search for organics, the chemical environments and physical-chemical processes that respectively preserve or destroy organics, and unexpectedly large variations in H, S, and Cl isotopes. In addition to a set of aromatic and aliphatic chorine containing organic compounds thermally released from the Cumberland mudstone drilled early in the mission compounds [Freissinet et al., 2015], additional S-containing organics have been identified in the Mojave drill sample in the Pahrump Hills section that was characterized in detail over a 5 month period. This set of S and Cl containing compounds is definitively identified by gas chromatograph mass spectrometer (GCMS) analyses. In addition, fragments of other organic compounds are evident in the evolved gas analysis (EGA) experiments implemented by the Sample Analysis at Mars (SAM) instrument and utilization of SAM's derivatization agent has revealed the presence of high molecular weight compounds. Two factors complicate the search for organic compounds preserved from ancient Mars. First the nearly ubiquitous oxychlorine compounds such as perchlorates decompose on heating in the SAM ovens in the EGA experiments and there is evidence that the hot O2 released combusts organic compounds to produce CO2. Secondly, the cosmic radiation that penetrates through the thin Mars atmosphere meters into the surface transforms near surface organic compounds over time. Fortunately, the SAM mass spectrometer can measure spallogenic (3He and 21Ne) and neutron-capture (36Ar) noble gases to secure an estimate of the duration of radiation exposure. Measurement protocols developed to work around both of these limitations will be discussed. C. Freissinet et al, JGR (2015) 120(3), 495-514.

  8. The problem of genesis and systematic of sedimentary units of hydrocarbon reservoirs

    Science.gov (United States)

    Zhilina, E. N.; Chernova, O. S.

    2017-12-01

    The problem of identifying and ranking sedimentation, facies associations and their constituent parts - lithogenetic types of sedimentary rocks was considered. As a basis for paleo-sedimentary modelling, the author has developed a classification for terrigenous natural reservoirs,that for the first time links separate sedimentological units into a single hierarchical system. Hierarchy ranking levels are based on a compilation of global knowledge and experience in sediment geology, sedimentological study and systematization, and data from deep-well coresrepresentingJurassichydrocarbon-bearing formationsof the southeastern margin of the Western Siberian sedimentary basin.

  9. Magmatic versus sedimentary volcanism: similarities of two different geological phenomena

    Science.gov (United States)

    Mazzini, Adriano

    2015-04-01

    Sedimentary volcanoes (or more commonly called mud volcanoes) are geological phenomena that are present in sedimentary basins of passive and active margins. At these localities gas and water related to hydrocarbon diagenetic and catagenetic production generate overpressure facilitating the rise of mobile and ductily deformable materials that breach through the denser overlying rocks. The results are surface powerful manifestations of mud eruptions that strikingly resemble to those of magmatic volcanoes. Magmatic and sedimentary volcanoes share many other similarities. Initially both systems are essentially gas driven and the subsurface plumbing systems are characterized by intrusions and a complex system of fractures and conduits that bifurcate from a central feeder channel that manifest in the surface as numerous satellite seeps and vents. In both cases are inferred secondary shallower chambers where reactions take place. Comparable structural morphologies (e.g. conical, elongated, pie-shaped, multicrater, swap-like, caldera collapse, subsiding flanks, plateau-like) and/or alteration of the original shape are in both cases related to e.g. density and viscosity of the erupted solids, to the gas content, to the frequency of the eruptions, and to the action of meteoric factors (e.g. strong erosion by rain, wind, temperature changes etc. etc.). Like for magmatic volcanoes, the periodicity of the eruptive activity is related to the time required to charge the system and create new overpressure, as well as how the structure seals during periods of dormancy. Earthquakes are documented to be a powerful trigger capable to activate faults (often hosting magmatic and sedimentary volcanoes) and/or facilitating the breaching of the upper layers, and allowing the rise of deeper charged fluids. Finally, both systems significantly contribute as active source for CH4 (sedimentary) and CO2 (magmatic) resulting of great importance for global budget estimates of sensitive gasses. The

  10. NMR studies of sedimentary tetrapyrroles

    Energy Technology Data Exchange (ETDEWEB)

    Keely, B.J.; Maxwell, J.R. (Univ. of Bristol (England))

    Structural assignments of sedimentary biological markers rely mostly on the use of GC and GC-MS techniques, involving both chromatographic and mass spectral comparisons with synthetic standards in addition to de facto mass spectral interpretation. Difficulties experienced in the analysis of sedimentary porphyrins by GC-MS (which until very recently required derivatization), and the desire to understand the origins and geochemical transformations of these components and their precursors, have led to more extensive structural investigations than usually accorded to other classes of biological marker. This paper briefly reviews recent developments in {sup 1}H NMR studies of chlorins and porphyrins of sedimentary origin, with particular reference to correlated spectroscopy (COSY), which allows elucidation of spin-coupled systems.

  11. Gravimetric survey and modeling of the basement morphology in the sedimentary thickness characterization, NE portion of Paraná Sedimentary Basin - Brazil

    Directory of Open Access Journals (Sweden)

    Maximilian Fries

    2017-05-01

    Full Text Available ABSTRACT: The northeast portion of the Paraná Sedimentary Basin is distinguished by structural highs as the known Pitanga Dome, an uplifted structure identified in the last century. It represents a geological and evolutionary evidence of the Paraná Sedimentary Basin and has undergone inspired studies and intense exploration surveys. This study consists of a gravimetric survey in the Pitanga Dome area, State of São Paulo, Brazil. The Bouguer gravity anomalies have been identified and related to the structural high, sedimentary thickness, and the basement morphology. Processing and enhancement techniques were used for forward modeling based on previous studies. The three models from profiles sectioning the dome have a sedimentary thickness varying from 200 to 1.250 meters. The adopted methodology has provided important results determining that the Pitanga Dome can be understood through rational 3D visualization. The area can be interpreted as an undulating basement with thinning of sedimentary rocks related to deep features (structures in the crust/mantle limit (Moho uplift. This characteristic is confirmed by the sedimentary layer thickening present throughout the surrounding area. The results also offer important insights and support for further studies concerning the genesis and evolution of this and other uplifted structures of the Paraná Sedimentary Basin.

  12. DOE workshop: Sedimentary systems, aqueous and organic geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    A DOE workshop on sedimentary systems, aqueous and organic geochemistry was held July 15-16, 1993 at Lawrence Berkeley Laboratory. Papers were organized into several sections: Fundamental Properties, containing papers on the thermodynamics of brines, minerals and aqueous electrolyte solutions; Geochemical Transport, covering 3-D imaging of drill core samples, hydrothermal geochemistry, chemical interactions in hydrocarbon reservoirs, fluid flow model application, among others; Rock-Water Interactions, with presentations on stable isotope systematics of fluid/rock interaction, fluid flow and petotectonic evolution, grain boundary transport, sulfur incorporation, tracers in geologic reservoirs, geothermal controls on oil-reservoir evolution, and mineral hydrolysis kinetics; Organic Geochemistry covered new methods for constraining time of hydrocarbon migration, kinetic models of petroleum formation, mudstones in burial diagenesis, compound-specific carbon isotope analysis of petroleums, stability of natural gas, sulfur in sedimentary organic matter, organic geochemistry of deep ocean sediments, direct speciation of metal by optical spectroscopies; and lastly, Sedimentary Systems, covering sequence stratigraphy, seismic reflectors and diagenetic changes in carbonates, geochemistry and origin of regional dolomites, and evidence of large comet or asteroid impacts at extinction boundaries.

  13. Formaldehyde as hypothetical primer of biohomochirality

    Energy Technology Data Exchange (ETDEWEB)

    Goldanskii, V.I. [N. N. Semenov Institute of Chemical Physics of the Russian Academy of Sciences, Kosygin Street 4, Moscow, 117334 (Russia)

    1996-07-01

    One of the most intriguing and crucial problems of the prebiotic evolution and the origin of life is the explanation of the origin of biohomochirality. A scheme of conversions originated by formaldehyde (FA) as hypothetical primer of biohomochirality is proposed. The merit of FA as executor of this function is based -inter alia - on the distinguished role of FA as one of the earliest and simplest molecules in both warm, terrestrial and cold, extraterrestrial scenarios of the origin of life. The confirmation of the role of FA as primer of biohomochirality would support the option of an RNA world as an alternative to the protein world. The suggested hypothesis puts forward for the first time a concrete sequence of chemical reactions which can lead to biohomochirality. The spontaneous breaking of the mirror symmetry is secured by the application of the well-known Frank scheme (combination of autocatalysis and {open_quote}{open_quote}annihilation{close_quote}{close_quote} of L and D enantiomers) to the series of interactions of FA {open_quote}{open_quote}trimers{close_quote}{close_quote} (i.e. C{sub 3}H{sub 6}O{sub 3} compounds) of (aaa), (apa) and (app) types, where the monomeric groups (a) means {open_quote}{open_quote}achirons{close_quote}{close_quote} (a=CH{sub n}, n{ge}2 and C=M, M=C,O) and (p) mean {open_quote}{open_quote}prochirons{close_quote}{close_quote} (p=HC{asterisk}OM, M=H,C). {copyright} {ital 1996 American Institute of Physics.}

  14. Well-log based prediction of temperature models in the exploration of sedimentary settings

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea; Wonik, Thomas

    these measurements are not available or only measured to a certain depth so that a temperature model needs to developed. A prerequisite for such a model is the knowledge of the regional heat flow and the geological conditions translated into lithology and thermal rock properties. For the determination of continuous...... borehole temperature profiles we propose a two-step procedure: (1) the use of standard petrophysical well logs and (2) the inversion of predicted TC to temperature gradients by applying Fourier’s law of heat conduction. The prediction of TC is solved by using set of equations (Fuchs & Förster, 2014......) developed for matrix TC of sedimentary rocks. The equations resulted from a statistical analysis of an artificial set of mineral assemblages (consisting of 15 rock-forming minerals) typical for the different types of sedimentary rocks. The matrix TC was transformed into bulk TC by using a well-log derived...

  15. Analyse géochimique de la matiére organique extraite des roches sédimentaires. IV. Extraction des roches en faible quantités Geochemical Analysis of Organic Matter Extracted from Sedimentary Rocks Iv. Exraction from Small Amounts of Rock

    Directory of Open Access Journals (Sweden)

    Monin J. C.

    2006-11-01

    Full Text Available L'extraction en Soxhlet est inappllcable lorsque les échantillons de roche sont de trop petite taille. A l'occasion de la mise au point du protocole d'extraction correspondant, on examine l'influence d'un certain nombre de conditions opératoires sur le rendement d'extraction : température, durée nature et quantité du solvant, présence de lumière, présence d'air, procédé d'extraction. Pour les hydrocarbures, tant saturés qu'aromatiques, le facteur essentiel est l'agitation du milieu d'extraction ; la nature du solvant n'est pas critique, à condition de ne pas choisir un très mauvais solvant des hydrocarbures : l'extractibilité est en effet plus fonction du pouvoir désorbant vis-à-vis de la roche que du pouvoir solvant proprement dit. Pour les résines et asphalténes, l'interprétation des résultats est délicate, car la frontière n'est pas nette entre produits simplement dissous, produits de solvolyse et, produits de néoformation par interaction solvant-matière organique-matière minérale. II n'existe donc pas de protocole d'extraction recommandable dans l'absolu. Tout dépend des exigences analytiques et aussi pratiques du laboratoire; à l'Institut Français du Pétrole (IFP le protocole retenu est l'extraction en bécher avec agitation magnétique pendant 20 min dans le chroroforme à 50 °C (approximativement; on donne aussi le protocole d'évaporation du solvant et de récupération de l'extrait, qui doit être étudié soigneusement étant donné les faibles quantités mises en jeu. A Soxhlet extractor cannot be used with rock samples that are too small in size. With the development of on extraction procédure for such cases, this article examines the influence of various operating conditions on extraction yield, i. e. temperature, duration, nature and amount of solvent, presence of light, présence of air and extraction process. For both saturated and aromatic hydrocarbons, the essential factor is the stirring of the

  16. Geothermal gradient map of Brazilian sedimentary basins; Gradiente geotermico das bacias sedimentares brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Zembruscki, Sylvio G.; Chang, Hung K. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    1989-07-01

    Studies in 21 Brazilian sedimentary basins applying temperature data obtained from oil well logging and drill stem tests are presented. The results permitted an characterization of geothermal gradient according the rocks formation and could be used as geothermal energy sources. The three main basins (Middle Amazonas, Barreirinhas and Parnaiba) had more complete studies and permit an evaluation of the geothermal temperature variation in function of the rocks formation on different geological periods (Paleozoic, Mesozoic and Cenozoic basins). 10 figs., 1 tab., 34 refs

  17. In Silico screening for functional candidates amongst hypothetical proteins

    DEFF Research Database (Denmark)

    Desler, Claus; Suravajhala, Prashanth; Sanderhoff, May

    2009-01-01

    BACKGROUND: The definition of a hypothetical protein is a protein that is predicted to be expressed from an open reading frame, but for which there is no experimental evidence of translation. Hypothetical proteins constitute a substantial fraction of proteomes of human as well as of other...

  18. Predictive characterization of hypothetical proteins in Staphylococcus aureus NCTC 8325.

    Science.gov (United States)

    School, Kuana; Marklevitz, Jessica; K Schram, William; K Harris, Laura

    2016-01-01

    Staphylococcus aureus is one of the most common hospital acquired infections. It colonizes immunocompromised patients and with the number of antibiotic resistant strains increasing, medicine needs new treatment options. Understanding more about the proteins this organism uses would further this goal. Hypothetical proteins are sequences thought to encode a functional protein but for which little to no evidence of that function exists. About half of the genomic proteins in reference strain S. aureus NCTC 8325 are hypothetical. Since annotation of these proteins can lead to new therapeutic targets, a high demand to characterize hypothetical proteins is present. This work examines 35 hypothetical proteins from the chromosome of S. aureus NCTC 8325. Examination includes physiochemical characterization; sequence homology; structural homology; domain recognition; structure modeling; active site depiction; predicted protein-protein interactions; protein-chemical interactions; protein localization; protein stability; and protein solubility. The examination revealed some hypothetical proteins related to virulent domains and protein-protein interactions including superoxide dismutase, O-antigen, bacterial ferric iron reductase and siderophore synthesis. Yet other hypothetical proteins appear to be metabolic or transport proteins including ABC transporters, major facilitator superfamily, S-adenosylmethionine decarboxylase, and GTPases. Progress evaluating some hypothetical proteins, particularly the smaller ones, was incomplete due to limited homology and structural information in public repositories. These data characterizing hypothetical proteins will contribute to the scientific understanding of S. aureus by identifying potential drug targets and aiding in future drug discovery.

  19. Interpretation of magnetic fabrics in the Dalma volcanic rocks and ...

    Indian Academy of Sciences (India)

    70

    SE trending Dalma volcano-sedimentary range of the East Indian Shield, extending from. Belpahari (West Midnapore district, West Bengal) in the east up to Chandil (East Singhbhum district, Jharkhand) in the west (Figure 2). The rock units consist of thick sequences of mafic- ultramafic volcanic rocks, lenses of basaltic ...

  20. A study of radioactive elements of various rocks in Pattani Province with gamma ray spectrometer

    Directory of Open Access Journals (Sweden)

    Kaewtubtim, P.

    2002-01-01

    Full Text Available The radioactivity of the three elements, potassium, uranium and thorium, in rocks of various types in Pattani Province was investigated by using a gamma ray spectrometer. It was found that potassium contents in igneous rocks, sedimentary rocks and metamorphic rocks were 6.29 %, 2.21% and 1.54 % respectively. Uranium equivalent contents in igneous rock, sedimentary rocks and metamorphic rocks were found to be 22.51 ppm, 11.25 ppm and 14.13 ppm, while thorium contents in these rocks were 21.78 ppm, 18.88 ppm and 18.15 ppm respectively. The results obtained were similar to those reported by Pungtip Ranglek (1995 for igneous rock at Liwong Pluton site in Thepha, Na Thawi, Chana and Saba Yoi Districts, Songkhla Province, and were about six times higher than those reported by Kittichai Wattananikorn (1994 for igneous rock in the northern part of Thailand.

  1. In Silico screening for functional candidates amongst hypothetical proteins

    Directory of Open Access Journals (Sweden)

    Sanderhoff May

    2009-09-01

    Full Text Available Abstract Background The definition of a hypothetical protein is a protein that is predicted to be expressed from an open reading frame, but for which there is no experimental evidence of translation. Hypothetical proteins constitute a substantial fraction of proteomes of human as well as of other eukaryotes. With the general belief that the majority of hypothetical proteins are the product of pseudogenes, it is essential to have a tool with the ability of pinpointing the minority of hypothetical proteins with a high probability of being expressed. Results Here, we present an in silico selection strategy where eukaryotic hypothetical proteins are sorted according to two criteria that can be reliably identified in silico: the presence of subcellular targeting signals and presence of characterized protein domains. To validate the selection strategy we applied it on a database of human hypothetical proteins dating to 2006 and compared the proteins predicted to be expressed by our selecting strategy, with their status in 2008. For the comparison we focused on mitochondrial proteins, since considerable amounts of research have focused on this field in between 2006 and 2008. Therefore, many proteins, defined as hypothetical in 2006, have later been characterized as mitochondrial. Conclusion Among the total amount of human proteins hypothetical in 2006, 21% have later been experimentally characterized and 6% of those have been shown to have a role in a mitochondrial context. In contrast, among the selected hypothetical proteins from the 2006 dataset, predicted by our strategy to have a mitochondrial role, 53-62% have later been experimentally characterized, and 85% of these have actually been assigned a role in mitochondria by 2008. Therefore our in silico selection strategy can be used to select the most promising candidates for subsequent in vitro and in vivo analyses.

  2. In Silico screening for functional candidates amongst hypothetical proteins.

    Science.gov (United States)

    Desler, Claus; Suravajhala, Prashanth; Sanderhoff, May; Rasmussen, Merete; Rasmussen, Lene Juel

    2009-09-16

    The definition of a hypothetical protein is a protein that is predicted to be expressed from an open reading frame, but for which there is no experimental evidence of translation. Hypothetical proteins constitute a substantial fraction of proteomes of human as well as of other eukaryotes. With the general belief that the majority of hypothetical proteins are the product of pseudogenes, it is essential to have a tool with the ability of pinpointing the minority of hypothetical proteins with a high probability of being expressed. Here, we present an in silico selection strategy where eukaryotic hypothetical proteins are sorted according to two criteria that can be reliably identified in silico: the presence of subcellular targeting signals and presence of characterized protein domains. To validate the selection strategy we applied it on a database of human hypothetical proteins dating to 2006 and compared the proteins predicted to be expressed by our selecting strategy, with their status in 2008. For the comparison we focused on mitochondrial proteins, since considerable amounts of research have focused on this field in between 2006 and 2008. Therefore, many proteins, defined as hypothetical in 2006, have later been characterized as mitochondrial. Among the total amount of human proteins hypothetical in 2006, 21% have later been experimentally characterized and 6% of those have been shown to have a role in a mitochondrial context. In contrast, among the selected hypothetical proteins from the 2006 dataset, predicted by our strategy to have a mitochondrial role, 53-62% have later been experimentally characterized, and 85% of these have actually been assigned a role in mitochondria by 2008.Therefore our in silico selection strategy can be used to select the most promising candidates for subsequent in vitro and in vivo analyses.

  3. From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.

    Science.gov (United States)

    Philippines Univ., Quezon City. Science Education Center.

    This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete…

  4. Geochemistry of shale and sedimentary pyrite as a proxy for gold fertility in the Selwyn basin area, Yukon

    Science.gov (United States)

    Sack, Patrick J.; Large, Ross R.; Gregory, Daniel D.

    2018-01-01

    Selwyn basin area strata contain sedimentary pyrite with Au above background levels when analyzed by laser ablation-inductively coupled mass spectrometry. Hyland Group rocks contain framboidal pyrite contents of 670 ppb Au, 1223 ppm As, and 5.3 ppm Te; the mean of all types of sedimentary pyrite in the Hyland Group is 391 ppb Au, 1489 ppm As, and 3.8 ppm Te. These levels are similar to sedimentary pyrite in host lithologies from major orogenic gold districts in New Zealand and Australia. Comparison of whole rock and pyrite data show that rocks deposited in continental slope settings with significant terrigenous input contain pyrite that is consistently enriched in Au, As, Te, Co, and Cu. Although data are limited, whole rock samples of stratigraphic units containing Au-rich pyrite also contain high Au, indicating that most of the Au is within sedimentary pyrite. Based on geologic characteristics and comparison of pyrite chemistry data with whole rock chemistry, Selwyn basin area strata have the necessary ingredients to form orogenic gold deposits: Au-enriched source rocks, metamorphic conditions permissive of forming a metamorphic ore fluid, and abundant structural preparation for channeling fluids and depositing ore.

  5. Optimization of Well Configuration for a Sedimentary Enhanced Geothermal Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Mengnan; Cho, JaeKyoung; Zerpa, Luis E.; Augustine, Chad

    2017-05-01

    The extraction of geothermal energy in the form of hot water from sedimentary rock formations could expand the current geothermal energy resources toward new regions. From previous work, we observed that sedimentary geothermal reservoirs with relatively low permeability would require the application of enhancement techniques (e.g., well hydraulic stimulation) to achieve commercial production/injection rates. In this paper we extend our previous work to develop a methodology to determine the optimum well configuration that maximizes the hydraulic performance of the geothermal system. The geothermal systems considered consist of one vertical well doublet system with hydraulic fractures, and three horizontal well configurations with open-hole completion, longitudinal fractures and transverse fractures, respectively. A commercial thermal reservoir simulation is used to evaluate the geothermal reservoir performance using as design parameters the well spacing and the length of the horizontal wells. The results obtained from the numerical simulations are used to build a response surface model based on the multiple linear regression method. The optimum configuration of the sedimentary geothermal systems is obtained from the analysis of the response surface model. The proposed methodology is applied to a case study based on a reservoir model of the Lyons sandstone formation, located in the Wattenberg field, Denver-Julesburg basin, Colorado.

  6. Recreating Rocks

    DEFF Research Database (Denmark)

    Posth, Nicole R

    2008-01-01

    Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers.......Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers....

  7. Modeling of the Sedimentary Interbedded Basalt Stratigraphy for the Idaho National Laboratory Probabilistic Seismic Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Suzette Payne

    2007-08-01

    This report summarizes how the effects of the sedimentary interbedded basalt stratigraphy were modeled in the probabilistic seismic hazard analysis (PSHA) of the Idaho National Laboratory (INL). Drill holes indicate the bedrock beneath INL facilities is composed of about 1.1 km of alternating layers of basalt rock and loosely consolidated sediments. Alternating layers of hard rock and “soft” loose sediments tend to attenuate seismic energy greater than uniform rock due to scattering and damping. The INL PSHA incorporated the effects of the sedimentary interbedded basalt stratigraphy by developing site-specific shear (S) wave velocity profiles. The profiles were used in the PSHA to model the near-surface site response by developing site-specific stochastic attenuation relationships.

  8. Modeling of the Sedimentary Interbedded Basalt Stratigraphy for the Idaho National Laboratory Probabilistic Seismic Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Suzette Payne

    2006-04-01

    This report summarizes how the effects of the sedimentary interbedded basalt stratigraphy were modeled in the probabilistic seismic hazard analysis (PSHA) of the Idaho National Laboratory (INL). Drill holes indicate the bedrock beneath INL facilities is composed of about 1.1 km of alternating layers of basalt rock and loosely consolidated sediments. Alternating layers of hard rock and “soft” loose sediments tend to attenuate seismic energy greater than uniform rock due to scattering and damping. The INL PSHA incorporated the effects of the sedimentary interbedded basalt stratigraphy by developing site-specific shear (S) wave velocity profiles. The profiles were used in the PSHA to model the near-surface site response by developing site-specific stochastic attenuation relationships.

  9. Rock-magnetic studies on hematite, maghemite and combustion-metamorphic rocks

    NARCIS (Netherlands)

    de Boer, C.B.

    1999-01-01

    This thesis is structured in three parts. Part I and II comprise fundamental research of the magnetic properties of hematite and maghemite, respectively, essential to improve the quality of paleomagnetic interpretations of sedimentary rocks in particular. The main purpose is to develop diagnostic

  10. Igneous-sedimentary petroleum systems; Sistemas petroliferos igneo-sedimentares

    Energy Technology Data Exchange (ETDEWEB)

    Eiras, Jaime Fernandes [Para Univ., Belem, PA (Brazil)]. E-mail: eiras@ufpa.br; Wanderley Filho, Joaquim Ribeiro [PETROBRAS S.A., Manaus, AM (Brazil). Unidade de Negocios-BSOL]. E-mail: jwand@petrobras.com.br

    2003-07-01

    Igneous-sedimentary petroleum systems are mixed systems in which one or more essential elements or processes are related to magmatic events. Many examples worldwide are presented to show the importance of igneous rocks in the exploratory activities, as well as in the petroleum occurrence. Volcanic ash layers are of great importance in stratigraphic correlation and elucidation of structures, particularly when they occur in thick nonfossiliferous strata. They are also good indicators of turbidite deposition where turbidity currents are related to earthquakes generated by magmatic events. Unconventional reservoirs can be created by volcanic eruptions or intrusions, crystallization, reworking, and fracturing. Unaltered igneous rocks can seal vertically and laterally conventional reservoirs due to its excellent cap capacity. Abnormal thermal effect of igneous rocks can compensate the lack of overburden in shallow basins. Structural or combined traps can be formed due to intrusions, such as folded, faulted, and unconformity traps. Porosity can be either primary or secondary, or both. Primary porosity mainly consists of cavities produced by gas volatilization during eruption and cooling. Secondary porosity refers to those pores that result from hydrothermal alteration, recrystallization, and dissolution by groundwater, and tectonic stress. It includes intercrystalline pores formed by crystallization of various secondary minerals, dissolution pores, and tectonic fractures. New technologies of petroleum development and production are encouraging to search for oil and gas within igneous rocks, and new discoveries are expected. (author)

  11. Art Rocks with Rock Art!

    Science.gov (United States)

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  12. Rock Physics

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2017-01-01

    Rock physics is the discipline linking petrophysical properties as derived from borehole data to surface based geophysical exploration data. It can involve interpretation of both elastic wave propagation and electrical conductivity, but in this chapter focus is on elasticity. Rock physics is based...... on continuum mechanics, and the theory of elasticity developed for statics becomes the key to petrophysical interpretation of velocity of elastic waves. In practice, rock physics involves interpretation of well logs including vertical seismic profiling (VSP) and analysis of core samples. The results...

  13. Comparing hypothetical versus non-hypothetical methods for measuring willingness to pay in a food context

    Directory of Open Access Journals (Sweden)

    Laura Martínez-Carrasco

    2015-12-01

    Full Text Available Choosing a valid procedure to measure willingness to pay (WTP is crucial for designating optimum price policies or for evaluating the demand for new products. This study compares two methods for obtaining WTP in a food context: a random nth price auction and an open-ended contingent valuation (CV question. Participants were regular salad tomato buyers of Alicante and they were randomly assigned to one of the two treatments. The products about which they would show their WTP were traditional tomato varieties. Both treatments were divided into three stages: in the first stage the only available information was a reference price for the tomatoes. In stages 2 and 3 we revealed the local origin and the organic grown of the tomatoes respectively. Our results show that in the auction the percentage of participants willing to pay the same or more than the reference price was between 20 and 30%. In the CV method this percentage was between 40 and 65%. The mean WTP in the auction, considering the whole of the individuals, was situated between 1.90 and 2.13 €/kg. These same results obtained through the CV were situated between 2.54 and 3.21 €/kg. The results confirmed the findings of previous papers in which the hypothetical bias of CV was clarified because it yields higher values for WTP than the auction, especially when referring to the number of individuals willing to pay more. Additionally, hedonic price models were estimated for the prices obtained by both methods with the result that in all the models, WTP was directly related to the price paid for the latest purchase of tomatoes.

  14. Comparing hypothetical versus non-hypothetical methods for measuring willingness to pay in a food context

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Carrasco, L.; Brugarolas, M.; Martínez-Poveda, A.; Ruiz-Martínez, J.J.

    2015-07-01

    Choosing a valid procedure to measure willingness to pay (WTP) is crucial for designating optimum price policies or for evaluating the demand for new products. This study compares two methods for obtaining WTP in a food context: a random nth price auction and an open-ended contingent valuation (CV) question. Participants were regular salad tomato buyers of Alicante and they were randomly assigned to one of the two treatments. The products about which they would show their WTP were traditional tomato varieties. Both treatments were divided into three stages: in the first stage the only available information was a reference price for the tomatoes. In stages 2 and 3 we revealed the local origin and the organic grown of the tomatoes respectively. Our results show that in the auction the percentage of participants willing to pay the same or more than the reference price was between 20 and 30%. In the CV method this percentage was between 40 and 65%. The mean WTP in the auction, considering the whole of the individuals, was situated between 1.90 and 2.13 €/kg. These same results obtained through the CV were situated between 2.54 and 3.21 €/kg. The results confirmed the findings of previous papers in which the hypothetical bias of CV was clarified because it yields higher values for WTP than the auction, especially when referring to the number of individuals willing to pay more. Additionally, hedonic price models were estimated for the prices obtained by both methods with the result that in all the models, WTP was directly related to the price paid for the latest purchase of tomatoes. (Author)

  15. A modified failure criterion for transversely isotropic rocks

    Directory of Open Access Journals (Sweden)

    Omid Saeidi

    2014-03-01

    Full Text Available A modified failure criterion is proposed to determine the strength of transversely isotropic rocks. Mechanical properties of some metamorphic and sedimentary rocks including gneiss, slate, marble, schist, shale, sandstone and limestone, which show transversely isotropic behavior, were taken into consideration. Afterward, introduced triaxial rock strength criterion was modified for transversely isotropic rocks. Through modification process an index was obtained that can be considered as a strength reduction parameter due to rock strength anisotropy. Comparison of the parameter with previous anisotropy indexes in literature showed reasonable results for the studied rock samples. The modified criterion was compared to modified Hoek-Brown and Ramamurthy criteria for different transversely isotropic rocks. It can be concluded that the modified failure criterion proposed in this study can be used for predicting the strength of transversely isotropic rocks.

  16. Shifting college students' epistemological framing using hypothetical debate problems

    Science.gov (United States)

    Hu, Dehui; Rebello, N. Sanjay

    2014-06-01

    Developing expertise in physics problem solving requires the ability to use mathematics effectively in physical scenarios. Novices and experts often perceive the use of mathematics in physics differently. Students' perceptions and how they frame the use of mathematics in physics play an important role in their physics problem solving. In this study, we examined students' epistemological framing about using mathematics in physics in two types of problems: a conventional problem and a hypothetical debate problem. We found that when solving a conventional physics problem, students tended to frame problem solving in physics as rote equation chasing, i.e., plugging quantities into a memorized physics equation. In hypothetical debate problems, students were more likely to be involved in quantitative or qualitative sense making. We conclude that hypothetical debate problems might be used as an instructional tool for engaging students in sense making while using mathematics in physics. Thus, it might be potentially useful for developing more expertlike problem solving expertise.

  17. Shifting college students’ epistemological framing using hypothetical debate problems

    Directory of Open Access Journals (Sweden)

    Dehui Hu

    2014-05-01

    Full Text Available Developing expertise in physics problem solving requires the ability to use mathematics effectively in physical scenarios. Novices and experts often perceive the use of mathematics in physics differently. Students’ perceptions and how they frame the use of mathematics in physics play an important role in their physics problem solving. In this study, we examined students’ epistemological framing about using mathematics in physics in two types of problems: a conventional problem and a hypothetical debate problem. We found that when solving a conventional physics problem, students tended to frame problem solving in physics as rote equation chasing, i.e., plugging quantities into a memorized physics equation. In hypothetical debate problems, students were more likely to be involved in quantitative or qualitative sense making. We conclude that hypothetical debate problems might be used as an instructional tool for engaging students in sense making while using mathematics in physics. Thus, it might be potentially useful for developing more expertlike problem solving expertise.

  18. Lexical exponents of hypothetical modality in Polish and Lithuanian

    Directory of Open Access Journals (Sweden)

    Roman Roszko

    2015-11-01

    To analyse both the languages there is used the method of theoretical contrastive studies, which the most important features are: (1 orienting the studies from the content grounds to the formal grounds, (2 using a semantic interlanguage as tertium comparationis. First of all, the content of hypothetical modality and its definition and paraphrase is given here. Next, the gradational character of this category is discussed. There are distinguished six groups of lexemes expressing the corresponding degrees of hypothetical modality — from a shadow of uncertainty (minimal degree of probability to an almost complete certainty (maximum degree of probability. The experimental Polish-Lithuanian corpus is widely applied in the studies.

  19. College Student Reporting Responses to Hypothetical and Actual Safety Concerns

    Science.gov (United States)

    Hollister, Brandon A.; Scalora, Mario J.; Hoff, Sarah M.; Hodges, Heath J.; Marquez, Allissa

    2017-01-01

    Campus violence prevention often includes proactively reducing crime through noticing and resolving concerning situations. Within these efforts, interventions aimed at enhancing reporting have been considered necessary. The current study explored several reporting influences on college students' responses to hypothetical and actual campus safety…

  20. Towards a formalization of the Hypothetical Monopoly Test

    NARCIS (Netherlands)

    Hinloopen, J.

    2008-01-01

    We provide the first formalization ever of the HypotheticalMonopoly Test (HMT) to identify relevant markets. This reveals that the outcome of the test crucially depends on the intensity of competition. For two types of competition intensities, one related to market structure and one related to firm

  1. Scaffolding for Argumentation in Hypothetical and Theoretical Biology Concepts

    Science.gov (United States)

    Weng, Wan-Yun; Lin, Yu-Ren; She, Hsiao-Ching

    2017-01-01

    The present study investigated the effects of online argumentation scaffolding on students' argumentation involving hypothetical and theoretical biological concepts. Two types of scaffolding were developed in order to improve student argumentation: continuous scaffolding and withdraw scaffolding. A quasi-experimental design was used with four…

  2. A Hypothetical Learning Trajectory for Conceptualizing Matrices as Linear Transformations

    Science.gov (United States)

    Andrews-Larson, Christine; Wawro, Megan; Zandieh, Michelle

    2017-01-01

    In this paper, we present a hypothetical learning trajectory (HLT) aimed at supporting students in developing flexible ways of reasoning about matrices as linear transformations in the context of introductory linear algebra. In our HLT, we highlight the integral role of the instructor in this development. Our HLT is based on the "Italicizing…

  3. Hypothetical Markets: Educational Application of Ronald Dworkin's "Sovereign Virtue"

    Science.gov (United States)

    Gough, Stephen

    2006-01-01

    The purpose of this paper is to consider, in principle and at the most general level, a particular possible approach to educational policy-making. This approach involves an education-specific application of the notion of hypothetical markets first developed in Ronald Dworkin's book "Sovereign Virtue: The theory and practice of equality" (2000).…

  4. Source rock

    Directory of Open Access Journals (Sweden)

    Abubakr F. Makky

    2014-03-01

    Full Text Available West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro, and well log data of some Cretaceous sequences including Abu Roash (E, F and G members, Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone produced from (mixed type I/II kerogen. The generation potential of kerogen in Abu Roash (E and G members and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III kerogen. Eventually, kerogen (type III of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, Tmax and Production index (PI indicates that Abu Roash (F member exciting in the onset of oil generation, whereas Abu Roash (E and G members, Kharita and Betty formations entered the peak of oil generation.

  5. Scattering from Rock and Rock Outcrops

    Science.gov (United States)

    2015-09-30

    Scattering from Rock and Rock Outcrops Derek R. Olson The Pennsylvania State University Applied Research Laboratory, P.O. Box 30 State...In terms of target detection and classification, scattering from exposed rock on the seafloor, (i.e., individual rocks and rock outcrops) presents...levels, and other statistical measures of acoustic scattering from rocks and rock outcrops is therefore critical. Unfortunately (and curiously

  6. Hydrothermal-sedimentary mineralization in the carbon-silicon formation of the Kyzylkum

    Energy Technology Data Exchange (ETDEWEB)

    Shumlyanskiy, V.A.

    1981-01-01

    The ore-bearing carbon-silicon of the Riphean and early Paleozoic age is represented by carbonaceous mica-quartz shales (auminizinskiy suite) and by the interstratification of carbonaceous micro-quartzites, dolomite limestone, dolomites and phyllite-type mica-silicon shales (taskazganskiy suite). With these deposits, stratified bodies of metasomatically changed effusive and intrusive rock of a preferred basic composition are found. Sedimentary-metamorphic rock with a carbon silicon formation is syngenetically enriched with manganese, phosphorous, lead, molybdenum, vanadium, zinc, silver and barium. Barium varies in the strength of its content and is patterned with, and encountered in, the form of phenocrysts. In the barium layers, pyrite, sphalerite, and calcium are noted. It is suggested that barium in the zones with active underwater vulcanization is of hydrothermal-sedimentary orign.

  7. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  8. Compaction of porous rock by dissolution on discrete stylolites

    DEFF Research Database (Denmark)

    Angheluta, Luiza; Mathiesen, Joachim; Aharonov, Einat

    2012-01-01

    Compaction of sedimentary porous rock by dissolution and precipitation is a complex deformation mechanism, that is often localized on stylolites and pressure solution seams. We consider a one-dimensional model of compaction near a thin clay-rich stylolite embedded in a porous rock. Under the assu......Compaction of sedimentary porous rock by dissolution and precipitation is a complex deformation mechanism, that is often localized on stylolites and pressure solution seams. We consider a one-dimensional model of compaction near a thin clay-rich stylolite embedded in a porous rock. Under...... the assumption that the clay enhances solubility, the model predicts a reactive transport away from the clay layer followed by pore cementation. The evolution of the porosity, reactant transport, and compaction rate are studied as functions of model parameters and shown to reach a stationary state. We find good...

  9. Igneous Rocks

    Science.gov (United States)

    Doe, Bruce R.

    “Igneous Rocks was written for undergraduate geology majors who have had a year of college-level chemistry and a course in mineralogy … and for beginning graduate students. Geologists working in industry, government, or academia should find this text useful as a guide to the technical literature up to 1981 and as an overview of topics with which they have not worked but which may have unanticipated pertinence to their own projects.” So starts the preface to this textbook.As one who works part time in research on igneous rocks, especially as they relate to mineral deposits, I have been looking for such a book with this avowed purpose in a field that has a choking richness of evolving terminology and a bewildering volume of interdisciplinary literature. In addition to the standard topics of igneous petrology, the book contains a chapter on the role of igneous activity in the genesis of mineral deposits, its value to geothermal energy, and the potential of igneous rocks as an environment for nuclear waste disposal. These topics are presented rather apologetically in the preface, but the author is to be applauded for including this chapter. The apology shows just how new these interests are to petrology. Recognition is finally coming that, for example, mineral deposits are not “sports of nature,” a view held even by many economic geologists as recently as the early 1960's; instead they are perfectly ordinary geochemical features formed by perfectly ordinary geologic processes. In fact, the mineral deposits and their attendant alteration zones probably have as much to tell us about igneous rocks as the igneous rocks have to tell us about mineral deposits.

  10. Layer Formation in Sedimentary Fingering Convection

    CERN Document Server

    Reali, J F; Alsinan, A; Meiburg, E

    2016-01-01

    When particles settle through a stable temperature or salinity gradient they can drive an instability known as sedimentary fingering convection. This phenomenon is thought to occur beneath sediment-rich river plumes in lakes and oceans, in the context of marine snow where decaying organic materials serve as the suspended particles, or in the atmosphere in the presence of aerosols or volcanic ash. Laboratory experiments of Houk and Green (1973) and Green (1987) have shown sedimentary fingering convection to be similar to the more commonly known thermohaline fingering convection in many ways. Here, we study the phenomenon using 3D direct numerical simulations. We find evidence for layer formation in sedimentary fingering convection in regions of parameter space where it does not occur for non-sedimentary systems. This is due to two complementary effects. Sedimentation affects the turbulent fluxes and broadens the region of parameter space unstable to the $\\gamma$-instability (Radko 2003) to include systems at l...

  11. Diffusivity database (DDB) for major rocks. Database for the second progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Haruo

    1999-10-01

    A database for diffusivity for a data setting of effective diffusion coefficients in rock matrices in the second progress report, was developed. In this database, 3 kinds of diffusion coefficients: effective diffusion coefficient (De), apparent diffusion coefficient (Da) and free water diffusion coefficient (Do) were treated. The database, based on literatures published between 1980 and 1998, was developed considering the following points. (1) Since Japanese geological environment is focused in the second progress report, data for diffusion are collected focused on Japanese major rocks. (2) Although 22 elements are considered to be important in performance assessment for geological disposal, all elements and aquatic tracers are treated in this database development considering general purpose. (3) Since limestone, which belongs to sedimentary rock, can become one of the natural resources and is inappropriate as a host rock, it is omitted in this database development. Rock was categorized into 4 kinds of rocks; acid crystalline rock, alkaline crystalline rock, sedimentary rock (argillaceous/tuffaceous rock) and sedimentary rock (psammitic rock/sandy stone) from the viewpoint of geology and mass transport. In addition, rocks around neutrality among crystalline rock were categorized into the alkaline crystalline rock in this database. The database is composed of sub-databases for 4 kinds of rocks. Furthermore, the sub-databases for 4 kinds of the rocks are composed of databases to individual elements, in which totally, 24 items such as species, rock name, diffusion coefficients (De, Da, Do), obtained conditions (method, porewater, pH, Eh, temperature, atmosphere, etc.), etc. are input. As a result of literature survey, for De values for acid crystalline rock, totally, 207 data for 18 elements and one tracer (hydrocarbon) have been reported and all data were for granitic rocks such as granite, granodiorite and biotitic granite. For alkaline crystalline rock, totally, 32

  12. Genome-wide screens for expressed hypothetical proteins

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Durhuus, Jon Ambæk; Rasmussen, Lene Juel

    2012-01-01

    A hypothetical protein (HP) is defined as a protein that is predicted to be expressed from an open reading frame, but for which there is no experimental evidence of translation. HPs constitute a substantial fraction of proteomes of human as well as of other organisms. With the general belief that...... that the majority of HPs are the product of pseudogenes, it is essential to have a tool with the ability of pinpointing the minority of HPs with a high probability of being expressed....

  13. Structural and Functional Annotation of Hypothetical Proteins of O139

    Directory of Open Access Journals (Sweden)

    Md. Saiful Islam

    2015-06-01

    Full Text Available In developing countries threat of cholera is a significant health concern whenever water purification and sewage disposal systems are inadequate. Vibrio cholerae is one of the responsible bacteria involved in cholera disease. The complete genome sequence of V. cholerae deciphers the presence of various genes and hypothetical proteins whose function are not yet understood. Hence analyzing and annotating the structure and function of hypothetical proteins is important for understanding the V. cholerae. V. cholerae O139 is the most common and pathogenic bacterial strain among various V. cholerae strains. In this study sequence of six hypothetical proteins of V. cholerae O139 has been annotated from NCBI. Various computational tools and databases have been used to determine domain family, protein-protein interaction, solubility of protein, ligand binding sites etc. The three dimensional structure of two proteins were modeled and their ligand binding sites were identified. We have found domains and families of only one protein. The analysis revealed that these proteins might have antibiotic resistance activity, DNA breaking-rejoining activity, integrase enzyme activity, restriction endonuclease, etc. Structural prediction of these proteins and detection of binding sites from this study would indicate a potential target aiding docking studies for therapeutic designing against cholera.

  14. Lithofacies and paleo depositional environment of the rocks of ...

    African Journals Online (AJOL)

    IKENNA

    2013-09-20

    Sep 20, 2013 ... environment. The intact shells of bivalves suggest deposition in a low energy protected shoreline where wave action is limited. Sedimentary structures like fissility and laminations, also suggest deposition in low energy marine setting. Pyroclastic rocks mapped in the area have been interpreted as volcanic ...

  15. In situ gamma radiation measurements in the Neoproterozoic rocks ...

    Indian Academy of Sciences (India)

    Natural gamma ray measurements using a portable device were performed at 157 sites in the area around Sirohi town and Sindreth village in Rajasthan (NW India). This region comprises sedimentary rocks, metasediments, granites and gneisses that bear characteristic GR dose values and U/Th ratios corresponding with ...

  16. Diagenetic evolution of Cenozoic sandstones, Gulf of Mexico sedimentary basin

    Science.gov (United States)

    Land, Lynton S.; Milliken, Kitty Lou; McBride, Earle F.

    1987-03-01

    The Gulf of Mexico sedimentary basin is a natural laboratory for the study of on-going diagenetic and incipient metamorphic processes. Sediments and rocks of Eocene through Pleistocene age have been studied from the surface to depths in excess of 6 km. Sediments heated to temperatures above 100°C have been massively transformed by mechanical compaction, cementation, and extensive alteration of detrital components. Grain dissolution, albitization, and clay-mineral transformations have reduced an initially complex detrital assemblage to quartz, albite, illite and minor carbonate at temperatures above 100°C. Volumetrically significant diagenetic processes observed in the basin include cementation by quartz, carbonate and kaolinite, grain dissolution (affecting mainly potassium feldspar, heavy minerals, and plagioclase), albitization, and the transformation of smectite to illite. Excepting carbonate cementation which shows essentially no depth-related variation, these processes occur shallower in older units, most likely in response to variations in the geothermal gradient, which is higher in the older Cenozoic depocenters. The magnitudes of the principal diagenetic processes all support the view that basinal diagenesis operates as an open system on a very large scale. Strontium isotopic data for authigenic carbonates document vertical transport on the scale of kilometers. The extent to which metamorphic processes below 6 km have effected the course of diagenesis in shallower rocks is still unproven, but current data suggest that burial diagenesis must be studied in such a context.

  17. Sedimentary facies and lithologic characters as main factors controlling hydrocarbon accumulations and their critical conditions

    Directory of Open Access Journals (Sweden)

    Jun-Qing Chen

    2015-10-01

    Full Text Available Taking more than 1000 clastic hydrocarbon reservoirs of Bohai Bay Basin, Tarim Basin and Junggar Basin, China as examples, the paper has studied the main controlling factors of hydrocarbon reservoirs and their critical conditions to reveal the hydrocarbon distribution and to optimize the search for favorable targets. The results indicated that the various sedimentary facies and lithologic characters control the critical conditions of hydrocarbon accumulations, which shows that hydrocarbon is distributed mainly in sedimentary facies formed under conditions of a long-lived and relatively strong hydrodynamic environment; 95% of the hydrocarbon reservoirs and reserves in the three basins is distributed in siltstones, fine sandstones, lithified gravels and pebble-bearing sandstones; moreover, the probability of discovering conventional hydrocarbon reservoirs decreases with the grain size of the clastic rock. The main reason is that the low relative porosity and permeability of fine-grained reservoirs lead to small differences in capillary force compared with surrounding rocks small and insufficiency of dynamic force for hydrocarbon accumulation; the critical condition for hydrocarbon entering reservoir is that the interfacial potential in the surrounding rock (Φn must be more than twice of that in the reservoir (Φs; the probability of hydrocarbon reservoirs distribution decreases in cases where the hydrodynamic force is too high or too low and when the rocks have too coarse or too fine grains.

  18. Demand curves for hypothetical cocaine in cocaine-dependent individuals.

    Science.gov (United States)

    Bruner, Natalie R; Johnson, Matthew W

    2014-03-01

    Drug purchasing tasks have been successfully used to examine demand for hypothetical consumption of abused drugs including heroin, nicotine, and alcohol. In these tasks, drug users make hypothetical choices whether to buy drugs, and if so, at what quantity, at various potential prices. These tasks allow for behavioral economic assessment of that drug's intensity of demand (preferred level of consumption at extremely low prices) and demand elasticity (sensitivity of consumption to price), among other metrics. However, a purchasing task for cocaine in cocaine-dependent individuals has not been investigated. This study examined a novel Cocaine Purchasing Task and the relation between resulting demand metrics and self-reported cocaine use data. Participants completed a questionnaire assessing hypothetical purchases of cocaine units at prices ranging from $0.01 to $1,000. Demand curves were generated from responses on the Cocaine Purchasing Task. Correlations compared metrics from the demand curve to measures of real-world cocaine use. Group and individual data were well modeled by a demand curve function. The validity of the Cocaine Purchasing Task was supported by a significant correlation between the demand curve metrics of demand intensity and O max (determined from Cocaine Purchasing Task data) and self-reported measures of cocaine use. Partial correlations revealed that after controlling for demand intensity, demand elasticity and the related measure, P max, were significantly correlated with real-world cocaine use. Results indicate that the Cocaine Purchasing Task produces orderly demand curve data, and that these data relate to real-world measures of cocaine use.

  19. [Study on optimal model of hypothetical work injury insurance scheme].

    Science.gov (United States)

    Ye, Chi-yu; Dong, Heng-jin; Wu, Yuan; Duan, Sheng-nan; Liu, Xiao-fang; You, Hua; Hu, Hui-mei; Wang, Lin-hao; Zhang, Xing; Wang, Jing

    2013-12-01

    To explore an optimal model of hypothetical work injury insurance scheme, which is in line with the wishes of workers, based on the problems in the implementation of work injury insurance in China and to provide useful information for relevant policy makers. Multistage cluster sampling was used to select subjects: first, 9 small, medium, and large enterprises were selected from three cities (counties) in Zhejiang Province, China according to the economic development, transportation, and cooperation; then, 31 workshops were randomly selected from the 9 enterprises. Face-to-face interviews were conducted by trained interviewers using a pre-designed questionnaire among all workers in the 31 workshops. After optimization of hypothetical work injury insurance scheme, the willingness to participate in the scheme increased from 73.87%to 80.96%; the average willingness to pay for the scheme increased from 2.21% (51.77 yuan) to 2.38% of monthly wage (54.93 Yuan); the median willingness to pay for the scheme increased from 1% to 1.2% of monthly wage, but decreased from 35 yuan to 30 yuan. The optimal model of hypothetical work injury insurance scheme covers all national and provincial statutory occupational diseases and work accidents, as well as consultations about occupational diseases. The scheme is supposed to be implemented worldwide by the National Social Security Department, without regional differences. The premium is borne by the state, enterprises, and individuals, and an independent insurance fund is kept in the lifetime personal account for each of insured individuals. The premium is not refunded in any event. Compensation for occupational diseases or work accidents is unrelated to the enterprises of the insured workers but related to the length of insurance. The insurance becomes effective one year after enrollment, while it is put into effect immediately after the occupational disease or accident occurs. The optimal model of hypothetical work injury insurance

  20. Geochemical Analysis for Sedimentary Emerald Mineralization in Western Emerald belt, Colombia

    Science.gov (United States)

    Nino Vasquez, Gabriel Felipe; Song, Sheng-Rong

    2017-04-01

    1Gabriel Felipe Nino Vasquez and 1Sheng-Rong Song 1Department of Geosciences, National Taiwan University Colombia hosts a large quantity of mineral resources due to its complex tectonic arrangement, and emerald deposits are one of the most representatives for the country. Emeralds in Colombia occur mainly in black shale, and are located in eastern Andes Cordillera with two parallel belts separated by approximately 130 Km: the Western belt (WB) and the Eastern belt (EB). The geological, mineralogical and tectonic features from these belts are quite similar (Buenaventura 2002). Previous researchers concluded that emeralds in Colombia came from hydrothermal sedimentary processes without any magmatic influence, and suggested that the source of Cr, V and Be (which are important components of the beryl) was the host rock. According to their results, the process which allowed the shale to release these cations was the metasomatism (albitization and carbonization), which was resulted from the interaction between the rocks and the alkaline brines. Fractures and fault planes originated by these tectonic movements were fulfilled by enriched fluids, which they allowed emeralds and the other minerals precipitation with decreasing alkalinity and pressure (Giuliani et al. 1994). However, there were several pitfalls of conclusions drawn from previous researches. Firstly, Cr and V were widely distributed and come from mafic and ultramafic rocks, and Be was mostly found in pegmatites, finding these elements in sedimentary rocks suggest that probably the ultramafic rocks occurred not far from the deposits. Secondly, there was an inconsistency in the estimated temperatures of emeralds formation, i.e. temperature of hydrothermal sedimentary deposits was only 200° C, while laboratory analysis showed that the formation of emeralds was higher than 300° C. Therefore, there might still be an allocthonus influence on emerald formation that significantly increases the temperature. This

  1. Imaging a pore network in a clay-rock at the sub-nanometer scale

    OpenAIRE

    Gaboreau, Stéphane; Pret², D; Tournassat, Christophe

    2017-01-01

    International audience; Mini-Symposium Description (2.22) Clayey rocks properties are the focus of an ever-increasing interest from the geoscience community. These fine-grained sedimentary rocks (mudstone, argillite, shalesetc.) are recognized as key-components for energy-related technologies, for which they could serve as isolation material (in radioactive waste disposal), caprocks (in CO 2 capture and storage systems), or as reservoir rocks for hydrocarbons (gas and oil shales) (Bourg, 2015...

  2. Phosphate rock resources of the United States

    Science.gov (United States)

    Cathcart, James Bachelder; Sheldon, Richard Porter; Gulbrandsen, Robert A.

    1984-01-01

    Coastal Plain phosphate province, principally in Florida and North Carolina and offshore in the shallow Atlantic Ocean from North Carolina to southern Florida. This resource is considered to be hypothetical because it is based on geologic inference combined with sparse drilling data. Total resources of phosphate rock in the United States are sufficient to supply domestic demands for the foreseeable future, provided that drilling is done to confirm hypothetical resources and the chemistry of the deposits is determined. Mining and beneficiation techniques will have to be modified or improved, and new techniques will have to be developed so that these deposits can be profitably exploited.

  3. Sedimentary dykes in the Oskarshamn-Vaestervik area. A study of the mechanism of formation

    Energy Technology Data Exchange (ETDEWEB)

    Roeshoff, Kennert [BBK AB, Solna (Sweden); Cosgrove, John [Imperial College, London (United Kingdom). Dept. of Earth Sciences and Engineering

    2002-07-01

    This study of the sedimentary dykes from the Oskarshamn-Vaestervik area, near Aespoe and surrounding region, is aimed at understanding the mechanism of their formation. In particular it is important to establish whether or not they formed by the injection of high pressure fluidized sediments and if so what the likely effect of any future over pressured sediments will be on the stability of the fracture network in the basement rocks at Aespoe. This report is made up of a review of the literature on sedimentary dykes, a discussion of the various mechanical models for hydraulic fracturing and a description of the field and laboratory study carried out on the sedimentary dykes. The literature review indicates a remarkable consensus on the mode of formation of these structures based on their fabric (particularly layering generated in part by variation in clast size) and the composition of the infilling material. Two modes of origin have been recognised. These are the passive infilling of dykes where the dyke material has entered an open fracture under the influence of gravity, and active, i.e. forceful injection of a fluidized sediment under high pressure into a pre-existing fracture or into a fracture generated by the high pressure fluid. The discussion of the theory of fluid induced fracturing leads to the recognition of three systems which are the two end members and an intermediate form of a complete spectrum of materials ranging from unconsolidated and incohesive sediments, through cemented but porous rocks to crystalline rocks with no intrinsic porosity and whose only porosity relates to that imparted by the fracture network that the rock contains. The theory best suited to analyses this latter system is one based on fracture mechanics and is known as the theory of external hydraulic fracturing. From the point of view of the sedimentary dykes in the study area around the Aespoe Hard Rock Laboratory, where the dykes occur in the fractured granitic basement, this is

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

    Science.gov (United States)

    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

  5. Further tests of entreaties to avoid hypothetical bias in referendum contingent valuation

    Science.gov (United States)

    Thomas C. Brown; Icek Ajzen; Daniel Hrubes

    2003-01-01

    Over-estimation of willingness to pay in contingent markets has been attributed largely to hypothetical bias. One promising approach for avoiding hypothetical bias is to tell respondents enough about such bias that they self-correct for it. A script designed for this purpose by Cummings and Taylor was used in hypothetical referenda that differed in payment amount. In...

  6. 47 CFR 69.608 - Carrier Common Line hypothetical net balance.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Carrier Common Line hypothetical net balance... SERVICES (CONTINUED) ACCESS CHARGES Exchange Carrier Association § 69.608 Carrier Common Line hypothetical net balance. The hypothetical net balance shall be equal to a Carrier Common Line revenue requirement...

  7. Sedimentary association of alternated mudstones and tight sandstones in China's oil and gas bearing basins and its natural gas accumulation

    Science.gov (United States)

    Zhu, Guangyou; Gu, Lijing; Su, Jin; Dai, Jinxing; Ding, Wenlong; Zhang, Jinchuan; Song, Lichen

    2012-05-01

    Oil and gas resources are abundant in China's continental sedimentary basins, where the main task of exploration has been finding oil for many years. In recent years, however, new discoveries of large-scale natural gas have been successively obtained. The natural gas mainly exists in the sedimentary association of alternated mudstones and tight sandstones and is dominantly low-permeability tight sand gas. Through the in-depth study on gas reservoir analysis, diagenetic evolution, source rock distribution and hydrocarbon-generating behavior, natural gas generation and accumulation, it is concluded that, during the major subsiding stage of large scale lake basins, the multicyclic subsiding process of the lake surface controls the development of high quality source rocks, the wide distribution of sands, and the superimposition of the two types of rocks in the vertical direction. The lacustrine muddy source rocks are developed, including mud shale, carbonaceous mudstone and coal bed which are in the medium-high evolution stage and produce mainly gas and the gas generation intensity is high. Through the analysis of the subsidence evolution processes of the Carboniferous-Permian Systems (transitional marine-continental facies) in the Ordos Basin and the Triassic Xujiahe Formation (continental facies) in the Sichuan Basin, it is concluded that the widely distributed sandbodies of delta facies, although with tight properties, are interbedded with source rocks and easy to accumulate natural gases. The natural gas is migrated and accumulated within small distance, and is characterized by large-area accumulation. Because of the strong hydrocarbon generation capacity, big thickness and stable distribution of the underlying mud shale, the potential of gas resources should not be underestimated. The geocyclicity of China's continental sedimentary basins controls the sedimentary association of alternated mudstones and tight sandstones, resulting in superimposed accumulations of

  8. Mechanical and chemical compaction model for sedimentary basin simulators

    Science.gov (United States)

    Schneider, F.; Potdevin, J. L.; Wolf, S.; Faille, I.

    1996-10-01

    This article presents a sediment compaction model for sedimentary basin simulators. The concepts previously used in sedimentary basin models are generalized and described in our model based on the formalism specific to rock and soil mechanics. Sediment compaction is described on a geological time scale by an elastoplastic model in which the elastic modulus and the strain hardening modulus increase when deformation increases. The plastic limit is the maximum vertical effective stress reached by the sediment. The rheology of the sediment is defined by a relationship that couples the porosity (or volume) of the sediment with the vertical effective stress, assuming uniaxial deformation. The model also incorporates a viscoplastic term in the compaction equation. This component macroscopically considers viscous compaction phenomena such as pressure-solution. The viscosity coefficient is considered to be a function of the temperature. Some theoretical considerations allow us to conclude that the thermal dependency of the viscosity is given with an Arrhenius law in which the activation energy ranges from 20 kJ / mole to 50 kJ / mole. Using viscosity coefficients extrapolated from previous laboratory experiments, a sensitivity study shows significant effects of viscous deformation on the compaction of basins older than 1 Ma. In another study, the viscosity coefficient is determined by matching the results of numerical simulations with laboratory and borehole data obtained from literature. For chalk a constant viscosity coefficient of 2.5 GPa · Ma (8 × 10 22 Pa · s) has been determined. Assuming viscosity as a function of temperature with an activation energy of 40 kJ / mole, chalk viscosity at 15°C is calibrated around 25 GPa · Ma. Simulations with different thermal gradients show that porosity is a function of the temperature. Furthermore, simulations covering different lengths of time, show that porosity is also a function of time.

  9. Sedimentary Environments Offshore Norway - Palaeozoic to Recent

    Energy Technology Data Exchange (ETDEWEB)

    Martinsen, Ole J.; Dreyer, Tom [eds.

    1999-07-01

    The report includes the extended abstracts from the conference, 71 in number. The presentations discuss the sedimentary characteristics of the North Sea area and the the methods used in the research, a thorough knowledge of which is important for economic exploration of the oil and gas resources of the North Sea.

  10. Hydrochemical characteristics of groundwater in sedimentary ...

    African Journals Online (AJOL)

    Wells and springs are the dominant potable water sources in the area of study used by the population. Studies of the characteristics of aquifer types and the hydrochemistry of groundwater in sedimentary, metamorphic, and volcanic aquifers in the southern part of Ndian Division indicated the presence of the following three ...

  11. CERN Rocks

    CERN Multimedia

    2004-01-01

    The 15th CERN Hardronic Festival took place on 17 July on the terrace of Rest 3 (Prévessin). Over 1000 people, from CERN and other International Organizations, came to enjoy the warm summer night, and to watch the best of the World's High Energy music. Jazz, rock, pop, country, metal, blues, funk and punk blasted out from 9 bands from the CERN Musiclub and Jazz club, alternating on two stages in a non-stop show.  The night reached its hottest point when The Canettes Blues Band got everybody dancing to sixties R&B tunes (pictured). Meanwhile, the bars and food vans were working at full capacity, under the expert management of the CERN Softball club, who were at the same time running a Softball tournament in the adjacent "Higgs Field". The Hardronic Festival is the main yearly CERN music event, and it is organized with the support of the Staff Association and the CERN Administration.

  12. Search for underground openings for in situ test facilities in crystalline rock

    Energy Technology Data Exchange (ETDEWEB)

    Wollenberg, H.A.; Strisower, B.; Corrigan, D.J.; Graf, A.N.; O' Brien, M.T.; Pratt, H.; Board, M.; Hustrulid, W.

    1980-01-01

    With a few exceptions, crystalline rocks in this study were limited to plutonic rocks and medium to high-grade metamorphic rocks. Nearly 1700 underground mines, possibly occurring in crystalline rock, were initially identified. Application of criteria resulted in the identification of 60 potential sites. Within this number, 26 mines and 4 civil works were identified as having potential in that they fulfilled the criteria. Thirty other mines may have similar potential. Most of the mines identified are near the contact between a pluton and older sedimentary, volcanic and metamorphic rocks. However, some mines and the civil works are well within plutonic or metamorphic rock masses. Civil works, notably underground galleries associated with pumped storage hydroelectric facilities, are generally located in tectonically stable regions, in relatively homogeneous crystalline rock bodies. A program is recommended which would identify one or more sites where a concordance exists between geologic setting, company amenability, accessibility and facilities to conduct in situ tests in crystalline rock.

  13. Rock type discrimination techniques using Landsat and Seasat image data

    Science.gov (United States)

    Blom, R.; Abrams, M.; Conrad, C.

    1981-01-01

    Results of a sedimentary rock type discrimination project using Seasat radar and Landsat multispectral image data of the San Rafael Swell, in eastern Utah, are presented, which has the goal of determining the potential contribution of radar image data to Landsat image data for rock type discrimination, particularly when the images are coregistered. The procedure employs several images processing techniques using the Landsat and Seasat data independently, and then both data sets are coregistered. The images are evaluated according to the ease with which contacts can be located and rock units (not just stratigraphically adjacent ones) separated. Results show that of the Landsat images evaluated, the image using a supervised classification scheme is the best for sedimentary rock type discrimination. Of less value, in decreasing order, are color ratio composites, principal components, and the standard color composite. In addition, for rock type discrimination, the black and white Seasat image is less useful than any of the Landsat color images by itself. However, it is found that the incorporation of the surface textural measures made from the Seasat image provides a considerable and worthwhile improvement in rock type discrimination.

  14. Compaction and sedimentary basin analysis on Mars

    Science.gov (United States)

    Gabasova, Leila R.; Kite, Edwin S.

    2018-03-01

    Many of the sedimentary basins of Mars show patterns of faults and off-horizontal layers that, if correctly understood, could serve as a key to basin history. Sediment compaction is a possible cause of these patterns. We quantified the possible role of differential sediment compaction for two Martian sedimentary basins: the sediment fill of Gunjur crater (which shows concentric graben), and the sediment fill of Gale crater (which shows outward-dipping layers). We assume that basement topography for these craters is similar to the present-day topography of complex craters that lack sediment infill. For Gunjur, we find that differential compaction produces maximum strains consistent with the locations of observed graben. For Gale, we were able to approximately reproduce the observed layer orientations measured from orbiter image-based digital terrain models, but only with a >3 km-thick donut-shaped past overburden. It is not immediately obvious what geologic processes could produce this shape.

  15. Radiological Consequence Analyses Following a Hypothetical Severe Accident in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Juyub; Kim, Juyoul [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    In order to reflect the lessons learned from the Fukushima Daiichi nuclear power plant accident, a simulator which is named NANAS (Northeast Asia Nuclear Accident Simulator) for overseas nuclear accident has been developed. It is composed of three modules: source-term estimation, atmospheric dispersion prediction and dose assessment. For the source-term estimation module, the representative reactor types were selected as CPR1000, BWR5 and BWR6 for China, Japan and Taiwan, respectively. Considering the design characteristics of each reactor type, the source-term estimation module simulates the transient of design basis accident and severe accident. The atmospheric dispersion prediction module analyzes the transport and dispersion of radioactive materials and prints out the air and ground concentration. Using the concentration result, the dose assessment module calculates effective dose and thyroid dose in the Korean Peninsula region. In this study, a hypothetical severe accident in Japan was simulated to demonstrate the function of NANAS. As a result, the radiological consequence to Korea was estimated from the accident. PC-based nuclear accident simulator, NANAS, has been developed. NANAS contains three modules: source-term estimation, atmospheric dispersion prediction and dose assessment. The source-term estimation module simulates a nuclear accident for the representative reactor types in China, Japan and Taiwan. Since the maximum calculation speed is 16 times than real time, it is possible to estimate the source-term release swiftly in case of the emergency. The atmospheric dispersion prediction module analyzes the transport and dispersion of radioactive materials in wide range including the Northeast Asia. Final results of the dose assessment module are a map projection and time chart of effective dose and thyroid dose. A hypothetical accident in Japan was simulated by NANAS. The radioactive materials were released during the first 24 hours and the source

  16. 3-D velocity structure model for long-period ground motion simulation of the hypothetical Nankai Earthquake

    Science.gov (United States)

    Kagawa, T.; Petukhin, A.; Koketsu, K.; Miyake, H.; Murotani, S.; Tsurugi, M.

    2010-12-01

    Three dimensional velocity structure model of southwest Japan is provided to simulate long-period ground motions due to the hypothetical subduction earthquakes. The model is constructed from numerous physical explorations conducted in land and offshore areas and observational study of natural earthquakes. Any available information is involved to explain crustal structure and sedimentary structure. Figure 1 shows an example of cross section with P wave velocities. The model has been revised through numbers of simulations of small to middle earthquakes as to have good agreement with observed arrival times, amplitudes, and also waveforms including surface waves. Figure 2 shows a comparison between Observed (dash line) and simulated (solid line) waveforms. Low velocity layers have added on seismological basement to reproduce observed records. The thickness of the layer has been adjusted through iterative analysis. The final result is found to have good agreement with the results from other physical explorations; e.g. gravity anomaly. We are planning to make long-period (about 2 to 10 sec or longer) simulations of ground motion due to the hypothetical Nankai Earthquake with the 3-D velocity structure model. As the first step, we will simulate the observed ground motions of the latest event occurred in 1946 to check the source model and newly developed velocity structure model. This project is partly supported by Integrated Research Project for Long-Period Ground Motion Hazard Maps by Ministry of Education, Culture, Sports, Science and Technology (MEXT). The ground motion data used in this study were provided by National Research Institute for Earth Science and Disaster Prevention Disaster (NIED). Figure 1 An example of cross section with P wave velocities Figure 2 Observed (dash line) and simulated (solid line) waveforms due to a small earthquake

  17. A public domain model for 1D temperature and rheology construction in basement-sedimentary geothermal exploration: an application to the Spanish Central System and adjacent basins

    NARCIS (Netherlands)

    Limberger, J.; Bonte, D.; Vicente, G. de; Beekman, F.; Cloetingh, S.; Wees, J.D. van

    2017-01-01

    Brittle basement and sedimentary rocks, in particular if these are underlain by radiogenic crust, are considered a prime target for enhanced geothermal systems (EGS). They are marked by high geothermal gradients, caused by radiogenic heat production, and are well suited to be used for geothermal

  18. PREDICTED SEDIMENTARY SECTION OF SUBGLACIAL LAKE VOSTOK

    Directory of Open Access Journals (Sweden)

    G. I. Leychenkov

    2012-01-01

    Full Text Available In early February 2012, the drill hole at the Vostok Station encountered theLakeVostokwater. This step is important to study the lake composition including possible microbial life and to model subglacial environments however, the next ambitious target of the Vostok Drilling Project is sampling of bottom sediments, which contain the unique record of ice sheet evolution and environmental changes in centralAntarcticafor millions of years. In this connection, the forecast of sedimentary succession based on existing geophysical data, study of mineral inclusions in the accretion ice cores and tectonic models is important task. Interpretation of Airborne geophysical data suggests thatLakeVostokis the part of spacious rift system, which exists at least from Cretaceous. Reflection and refraction seismic experiments conducted in the southern part ofLakeVostokshow very thin (200–300 m stratified sedimentary cover overlying crystalline basement with velocity of 6.0–6.2 km/s. At present, deposition in southernLakeVostokis absent and similar conditions occurred likely at least last3 m.y. when ice sheet aboveLakeVostokchanged insignificantly. It can be also inferred that from the Late Miocene the rate of deposition inLakeVostokwas extremely low and so the most of sedimentary section is older being possibly of Oligocene to early to middle Miocene age when ice sheet oscillated and deposition was more vigorous. If so, the sampling of upper few meters of this condensed section is very informative in terms of history of Antarctic glaciation. Small thickness of sedimentary cover raises a question about existence of lake (rift depression during preglacial and early glacial times.

  19. Rock and Mineral Bingo: Applying and Assessing Student Rock and Mineral Knowledge and Identification Skills

    Science.gov (United States)

    Pound, K. S.

    2005-12-01

    A rock and mineral "Bingo" that is based on knowledge and identification skills (not luck) was developed to help teachers and introductory as well as more advanced-level students develop and improve rock and mineral identification skills. The game was initially designed to use a rock and mineral kit provided to all students in Lab Classes, but could be adapted for any suite of samples. The rock and mineral kits include 13 mineral samples (olivine, pyroxene, amphibole, biotite, muscovite, potassium feldspar, plagioclase, quartz, galena, gypsum, hematite, pyrite, calcite), 7 igneous rock samples (rhyolite, granite, andesite, diorite, basalt, gabbro, peridotite), 3 sedimentary rock samples (sandstone, shale, limestone), and 5 metamorphic rock samples (slate, mica schist, gneiss, marble, quartzite). The kit also includes a small magnifying glass, a streak plate and a tempered steel nail. The Bingo cards are composed of 9 squares ("questions") each. A total of 8 groups of questions have been developed to encompass introductory through more advanced levels. The question sets developed so far are: (a) General distinction between rocks and minerals; (b) Igneous, sedimentary and metamorphic rocks; (c) Mineral luster; (d) Mineral fracture and cleavage; (e) Mineral crystal form; (f) Mineral chemistry; (g) General mineralogy; (h) Geologic Context. Each square on the card is numbered (1-9). The same card is used for each group of questions. The questions are written on a separate set of small question cards that are color-coded (according to question set) and numbered. These cards are pulled out of the `bag' by the caller, and a copy of the question is posted for all to see. The players need to choose the sample from their collection that best fits the question or description given by the caller. The questions are set up so that some samples fit more than one answer, which requires the students to review their choices. The first person or group to win presents their board and

  20. Rollerjaw Rock Crusher

    Science.gov (United States)

    Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

    2009-01-01

    The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

  1. Estimation of vanadyl porphyrin concentration in sedimentary kerogens and asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Premovic, P.I.; Allard, T.; Nikolic, N.D.; Tonsa, I.R.; Pavlovic, M.S. [University of Nis, Nis (Yugoslavia). Dept. of Chemistry

    2000-05-01

    The authors describe a new, rapid method for determining the concentration of vanadyl prophyrins (VO{sup 2+}-P) associated with the kerogen of bituminous sedimentary rocks using electron spin resonance (ESR). The method is simple, straightforward and inexpensive. Several concentrations of a vanadyl (VO{sup 2+}) standard dissolved in glycerol-lignite-mixture were prepared. The VO{sup 2+} concentrations ranged from 100 to 1000 ppm. The anisotropic ESR spectra of both the standards and kerogen samples were recorded at room temperature and the integrated areas of the pre-selected ESR line (attributed to nuclear spin m{sub 1} = -5/2) were computed. The concentrations of VO{sup 2+} found in the kerogen samples were calculated using the relative ratio of the integrated areas for the standards and the kerogen samples. The VO{sup 2+}-P concentrations of the kerogen materials were then calculated using 450 as the mean molecular weight of these species. Quantitative determination of VO{sup 2+}-P in the kerogen fractions in the range of 800-8000 ppm and higher is feasible by the method reported. The method of analysis was also extended to the asphaltene samples (enriched with VO{sup 2+}-P) and a coal sample containing non-porphyrin VO{sup 2+} associated with its organic fraction. 20 refs., 5 figs., 1 tab.

  2. THE INFLUENCE OF SUBMERGED MACROPHYTES ON SEDIMENTARY DIATOM ASSEMBLAGES(1).

    Science.gov (United States)

    Vermaire, Jesse C; Prairie, Yves T; Gregory-Eaves, Irene

    2011-12-01

    Submerged macrophytes are a central component of lake ecosystems; however, little is known regarding their long-term response to environmental change. We have examined the potential of diatoms as indicators of past macrophyte biomass. We first sampled periphyton to determine whether habitat was a predictor of diatom assemblage. We then sampled 41 lakes in Quebec, Canada, to evaluate whether whole-lake submerged macrophyte biomass (BiomEpiV) influenced surface sediment diatom assemblages. A multivariate regression tree (MRT) was used to construct a semiquantitative model to reconstruct past macrophyte biomass. We determined that periphytic diatom assemblages on macrophytes were significantly different from those on wood and rocks (ANOSIM R = 0.63, P macrophyte, nutrient-limited lakes (BiomEpiV ≥525 μg · L(-1) ; total phosphorus [TP] macrophyte, nutrient-limited lakes (BiomEpiV eutrophic lakes (TP ≥35 μg · L(-1) ; six lakes). A semiquantitative model correctly predicted the MRT group of the lake 71% of the time (P macrophytes have a significant influence on diatom community structure and that sedimentary diatom assemblages can be used to infer past macrophyte abundance. © 2011 Phycological Society of America.

  3. Large-scale screening of hypothetical metal-organic frameworks

    Science.gov (United States)

    Wilmer, Christopher E.; Leaf, Michael; Lee, Chang Yeon; Farha, Omar K.; Hauser, Brad G.; Hupp, Joseph T.; Snurr, Randall Q.

    2012-02-01

    Metal-organic frameworks (MOFs) are porous materials constructed from modular molecular building blocks, typically metal clusters and organic linkers. These can, in principle, be assembled to form an almost unlimited number of MOFs, yet materials reported to date represent only a tiny fraction of the possible combinations. Here, we demonstrate a computational approach to generate all conceivable MOFs from a given chemical library of building blocks (based on the structures of known MOFs) and rapidly screen them to find the best candidates for a specific application. From a library of 102 building blocks we generated 137,953 hypothetical MOFs and for each one calculated the pore-size distribution, surface area and methane-storage capacity. We identified over 300 MOFs with a predicted methane-storage capacity better than that of any known material, and this approach also revealed structure-property relationships. Methyl-functionalized MOFs were frequently top performers, so we selected one such promising MOF and experimentally confirmed its predicted capacity.

  4. Errors affect hypothetical intertemporal food choice in women.

    Directory of Open Access Journals (Sweden)

    Manuela Sellitto

    Full Text Available Growing evidence suggests that the ability to control behavior is enhanced in contexts in which errors are more frequent. Here we investigated whether pairing desirable food with errors could decrease impulsive choice during hypothetical temporal decisions about food. To this end, healthy women performed a Stop-signal task in which one food cue predicted high-error rate, and another food cue predicted low-error rate. Afterwards, we measured participants' intertemporal preferences during decisions between smaller-immediate and larger-delayed amounts of food. We expected reduced sensitivity to smaller-immediate amounts of food associated with high-error rate. Moreover, taking into account that deprivational states affect sensitivity for food, we controlled for participants' hunger. Results showed that pairing food with high-error likelihood decreased temporal discounting. This effect was modulated by hunger, indicating that, the lower the hunger level, the more participants showed reduced impulsive preference for the food previously associated with a high number of errors as compared with the other food. These findings reveal that errors, which are motivationally salient events that recruit cognitive control and drive avoidance learning against error-prone behavior, are effective in reducing impulsive choice for edible outcomes.

  5. Disability and marginal utility of income: evidence from hypothetical choices.

    Science.gov (United States)

    Tengstam, Sven

    2014-03-01

    It is often assumed that disability reduces the marginal utility of income. In this article, individuals' marginal utility of income in two states-(i) paralyzed in both legs from birth and (ii) not mobility impaired at all-is measured through hypothetical choices between imagined lotteries behind a so-called veil of ignorance. The outcomes of the lotteries include both income and disability status. It is found that most people have higher marginal utility when paralyzed than when not mobility impaired at all. The two marginal utilities are evaluated at the same levels of income. Having personal experience of mobility impairment and supporting the Left Party, the Social Democratic Party, the Green Party, or the Liberal Party are associated with having a higher marginal utility when paralyzed. The results suggest that more than full insurance of income losses connected to being disabled is optimal. The results further suggest that, given a utilitarian social welfare function, resources should be transferred to rather than from disabled people. Finally, if the transfers are not large enough to smooth out the marginal utilities of the disabled and the nondisabled, distributional weights based on disability status should be used in cost-benefit analysis. Copyright © 2013 John Wiley & Sons, Ltd.

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

    Directory of Open Access Journals (Sweden)

    Anna Xu

    2016-11-01

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

  7. Sedimentary Cover of the Central Arctic

    Science.gov (United States)

    Kireev, Artem; Poselov, Viktor; Butsenko, Viktor; Smirnov, Oleg

    2017-04-01

    Partial revised Submission of the Russian Federation for establishment of the OLCS (outer limit of the continental shelf) in the Arctic Ocean is made to include in the extended continental shelf of the Russian Federation, in accordance with article 76 of the Convention, the seabed and its subsoil in the central Arctic Ocean which is natural prolongation of the Russian land territory. To submit partial revised Submission in 2016, in 2005 - 2014 the Russian organizations carried out a wide range of geophysical studies, so that today over 23000 km of MCS lines, over hundreds of wide-angle reflection/refraction seismic sonobuoy soundings and 4000 km of deep seismic sounding are accomplished. All of these MCS and seismic soundings data were used to establish the seismic stratigraphy model of the Arctic region. Stratigraphy model of the sedimentary cover was successively determined for the Cenozoic and pre-Cenozoic parts of the section and was based on correlation of the Russian MCS data and seismic data documented by existing boreholes. Interpretation of the Cenozoic part of the sedimentary cover was based on correlation of the Russian MCS data and AWI91090 section calibrated by ACEX-2004 boreholes on the Lomonosov Ridge for Amerasia basin and by correlation of onlap contacts onto oceanic crust with defined magnetic anomalies for Eurasia basin, while interpretation of the Pre-Cenozoic part of the sedimentary cover was based on correlation with MCS and boreholes data from Chukchi sea shelf. Six main unconformities were traced: regional unconformity (RU), Eocene unconformity (EoU) (for Eurasia basin only), post-Campanian unconformity (pCU), Brookian (BU - base of the Lower Brookian unit), Lower Cretaceous (LCU) and Jurassic (JU - top of the Upper Ellesmerian unit). The final step in our research was to estimate the total thickness of the sedimentary cover of the Arctic Ocean and adjacent Eurasian shelf using top of acoustic basement correlation data and bathymetry data

  8. Triassic rift-related sedimentary basins in northern Chile (24° 29°S)

    Science.gov (United States)

    Suarez, M.; Bell, C. M.

    1992-10-01

    Triassic rocks in northern Chile (latitude 24°-29°S) include marine and continental rift-related sedimentary deposits, associated with basaltic, andesitic, and silicic volcanic rocks. Five main successions include the deposits of two marine basins (Profeta and San Félix) separated by three continental basins (Cifuncho, La Ternera, and La Coipa). The marine strata include turbidites and debris flow deposits interpreted as coarse-grained fan-delta sediments. The continental sediments include lacustrine fan delta, open lake, braided river, alluvial fan, and sabkha deposits. The widespread fan-delta systems (both marine and lacustrine), together with abrupt lateral and vertical facies discontinuities and large-scale depositional cycles, are indicative of rift-controlled sedimentation. The associated magmatic activity indicates that this rifting was the product of subduction-related extension or strike-slip movement on the active plate margin. Triassic rifting was followed in Late Triassic to Early Jurassic times by widespread thermotectonic subsidence.

  9. Discussion of gas enrichment mechanism and natural gas origin in marine sedimentary basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, G.Y.; Zhao, W.Z.; Zhang, S.C.; Liang, Y.B.; Wang, Z.J.

    2007-11-15

    There are abundant natural gas resources in Chinese marine sedimentary basin. The exploration hot shots of natural gas are the Palaeozoic marine strata here in recent years, and several large scale gas fields have been discovered. Chinese Palaeozoic high-post matured and coal measure hydrocarbon source rocks are mainly prone to gas generation in the present. This research considered that gas source rocks and TSR are the key cause of gas enrichment of marine strata. High-quality argillaceous and coal measure hydrocarbon rocks are distributed widely in the Palaeozoic marine strata, which have been in highly matured phase in the present. The argillaceous source rock generally contains various sulfates that could accelerate crude oil cracking to gas for TSR occurrence, and coal measure source rock mainly generates gas, so Chinese marine basin gives priority to accumulating gas. Marine strata have not founded oil reservoirs in the Sichuan Basin and Ordos Basin, and they consist mainly of dry gas. Marine natural gases are the mixed gases of oil cracking gas and coal-formed gas in a general way, oil cracking gases contain usually some H{sub 2}S and CO{sub 2}. Hydrocarbon carbon isotopes are very complicated, and methane and ethane isotopic values bear apparent reversal caused by thermal evolution and mixing among different genetic types of natural gas. Coal-formed gases are the main component of Chinese marine natural gas. The Upper Permian of the Sichuan Basin and the Carboniferous-Permian of the Ordos Basin coal measure hydrocarbon source rock present large hydrocarbon generation potential, which are the prospecting highlight of marine natural gas hereafter. Oil cracking gas exploration will be paid much attention to in the Tarim Basin because of the lack of coal measure hydrocarbon source rock.

  10. Delay discounting of hypothetical monetary rewards with decoys.

    Science.gov (United States)

    Kowal, Benjamin P; Faulkner, Jennifer L

    2016-01-01

    The current research attempted to decrease individuals' rates of delay discounting by introducing decoys that are similar but inferior to delayed rewards. Two experiments in the current study compared patterns of delay discounting generated by repeated choices between two hypothetical monetary rewards in the absence or presence of a decoy. Binary questionnaires (i.e., decoy absent) included questions with two options: a smaller-sooner (SS) reward and a larger-later (LL) reward. Trinary questionnaires (i.e., decoy present) included questions with three options: an SS reward, an LL reward, and a decoy. If an option is at least as rewarding on every dimension of value as an alternative and the option is more rewarding than an alternative on at least one dimension, then the option is considered to dominate the alternative (Wedell, 1991). The first experiment assessed the influence of decoys dominated by LL rewards (LL(-) decoys), which were constructed to be similar (on the dimension of amount) but inferior (on the dimension of delay) to LL rewards. The second experiment examined the effects of counterbalancing the order of binary and trinary questionnaires. In the first experiment, participants discounted to a lesser degree when LL(-) decoys were present as compared to when they were absent. In the second experiment, participants only discounted to a lesser degree on trinary questionnaires with LL(-) decoys when they had not previously completed binary questionnaires. Patterns of discounting generated by binary questionnaires were similar to those generated by trinary questionnaires when decoys are present; however, the degree to which individuals discounted delayed rewards was affected by the number of and type of options that were available. The current results join previous evidence suggesting that rates of delay discounting are sensitive to a variety of contextual influences. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Uniaxial Compressive Strengths of Rocks Drilled at Gale Crater, Mars

    Science.gov (United States)

    Peters, G. H.; Carey, E. M.; Anderson, R. C.; Abbey, W. J.; Kinnett, R.; Watkins, J. A.; Schemel, M.; Lashore, M. O.; Chasek, M. D.; Green, W.; Beegle, L. W.; Vasavada, A. R.

    2018-01-01

    Measuring the physical properties of geological materials is important for understanding geologic history. Yet there has never been an instrument with the purpose of measuring mechanical properties of rocks sent to another planet. The Mars Science Laboratory (MSL) rover employs the Powder Acquisition Drill System (PADS), which provides direct mechanical interaction with Martian outcrops. While the objective of the drill system is not to make scientific measurements, the drill's performance is directly influenced by the mechanical properties of the rocks it drills into. We have developed a methodology that uses the drill to indicate the uniaxial compressive strengths of rocks through comparison with performance of an identically assembled drill system in terrestrial samples of comparable sedimentary class. During this investigation, we utilize engineering data collected on Mars to calculate the percussive energy needed to maintain a prescribed rate of penetration and correlate that to rock strength.

  12. Burial stress and elastic strain of carbonate rocks

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2014-01-01

    strain multiplied by the rock frame modulus. We cannot measure the strain directly in the subsurface, but from the data on bulk density and P‐wave velocity, we can estimate the rock frame modulus and Biot's coefficient and then calculate the “effective vertical stress” as the total vertical stress minus......Burial stress on a sediment or sedimentary rock is relevant for predicting compaction or failure caused by changes in, e.g., pore pressure in the subsurface. For this purpose, the stress is conventionally expressed in terms of its effect: “the effective stress” defined as the consequent elastic...... the product of pore pressure and Biot's coefficient. We can now calculate the elastic strain by dividing “effective stress” with the rock frame modulus. By this procedure, the degree of elastic deformation at a given time and depth can be directly expressed. This facilitates the discussion of the deformation...

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

    Science.gov (United States)

    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.

  14. Sedimentary particulate iron: the missing micronutrients ?

    Science.gov (United States)

    Beghoura, Houda; Gorgues, Thomas; Aumont, Olivier; Planquette, Hélène

    2017-04-01

    Iron is known to regulate the marine primary production and to impact the structure of ecosystems. Indeed, iron is the limiting nutrient for the phytoplankton growth over about 30% of the global ocean. However, the nature of the external sources of iron to the ocean and their quantification remain uncertain. Among these external sources, the sediment sources have been recently shown to be underestimated. Besides, since the operationally defined dissolved iron (which is the sum of truly dissolved and colloidal iron) was traditionally assumed to be the only form available to phytoplankton and bacteria, most studies have focused on the supply of dissolved iron to the ocean, the role of the particulate fraction of iron being largely ignored. This traditional view has been recently challenged, noticeably, by observational evidences. Indeed, in situ observations have shown that large amounts of particulate iron are being resuspended from continental margins to the open ocean thanks to fine grained particles' transport over long distances. A fraction of this particulate iron may dissolve and thereby fuel the phytoplankton growth. The magnitude of the sedimentary sources of particulate iron and the releasing processes affecting this iron phase are not yet well constrained or quantified. As a consequence, the role of sedimentary particulate iron in the biogeochemical cycles is still unclear despite its potentially major widespread importance. Here, we propose a modeling exercise to assess the first order impacts of this newly considered particulate sedimentary iron on global ocean biogeochemistry. We designed global experiments with a coupled dynamical-biogeochemical model (NEMO-PISCES). First, a control simulation that includes only a sediment source of iron in the dissolved phase has been run. Then, this control simulation is being compared with simulations, in which we include a sediment source of iron in both phases (dissolved as well as particulate). Those latter

  15. Prediction of hydrocarbons in sedimentary basins

    Science.gov (United States)

    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.

  16. Basement Fault Reactivation by Fluid Injection into Sedimentary Reservoirs

    Science.gov (United States)

    Peter, Eichhubl; Fan, Zhiqiang; Zhu, Cheng

    2017-04-01

    Many suspected injection-induced earthquakes occur in crystalline basement rather than in the overlying sedimentary injection reservoir. To address why earthquakes nucleate in the basement rather than the injection layer we investigate the relationship between pore pressure diffusion, rock matrix deformation, and induced fault reactivation through 3D fully coupled poroelastic finite element models. These models simulate the temporal and spatial perturbation of pore pressure and solid stresses within a basement fault that extends into overlying sedimentary layers and that is conductive for flow along the fault but a barrier for flow across. We compare the effects of direct pore pressure communication and indirect poroelastic stress transfer from the injection reservoir to the fault on increasing the Coulomb failure stress that could reactivate the basement fault for normal, reverse, and strike-slip faulting stress regimes. Our numerical results demonstrate that volumetric expansion of the reservoir causes a bending of the fault near the injector and induces shear tractions along the downdip direction of the fault in the basement. These induced shear tractions act to increase the Coulomb failure stress for a normal faulting stress regime, and decrease the Coulomb failure stress for a reverse faulting regime. For a strike-slip faulting stress regime, the induced shear tractions increase the Coulomb failure stress both in the reservoir and basement. The induced normal traction on the fault reduces the Coulomb failure stress in all three tectonic regimes, but is larger in the reservoir than in the basement due to the more pronounced poroelastic effect in the reservoir. As a result, strike-slip stress regimes favor fault reactivation in the basement. Whereas the magnitude of the direct pore pressure increase exceeds the magnitude of induced poroelastic stress change, the poroelastic stress change increases the Coulomb failure stress in the basement fault for the normal

  17. Electrical resistivity dynamics beneath a fractured sedimentary bedrock riverbed in response to temperature and groundwater-surface water exchange

    Science.gov (United States)

    Steelman, Colby M.; Kennedy, Celia S.; Capes, Donovan C.; Parker, Beth L.

    2017-06-01

    Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwater-surface water exchange. In this study, surface electrical methods were used as a non-invasive technique to assess the scale and temporal variability of riverbed temperature and groundwater-surface water interaction beneath a sedimentary bedrock riverbed. Conditions were monitored at a semi-daily to semi-weekly interval over a full annual period that included a seasonal freeze-thaw cycle. Surface electromagnetic induction (EMI) and electrical resistivity tomography (ERT) methods captured conditions beneath the riverbed along a pool-riffle sequence of the Eramosa River in Canada. Geophysical datasets were accompanied by continuous measurements of aqueous specific conductance, temperature, and river stage. Time-lapse vertical temperature trolling within a lined borehole adjacent to the river revealed active groundwater flow zones along fracture networks within the upper 10 m of rock. EMI measurements collected during cooler high-flow and warmer low-flow periods identified a spatiotemporal riverbed response that was largely dependent upon riverbed morphology and seasonal groundwater temperature. Time-lapse ERT profiles across the pool and riffle sequence identified seasonal transients within the upper 2 and 3 m of rock, respectively, with spatial variations controlled by riverbed morphology (pool versus riffle) and dominant surficial rock properties (competent versus weathered rock rubble surface). While the pool and riffle both exhibited a dynamic resistivity through seasonal cooling and warming cycles, conditions beneath the pool were more variable, largely due to the formation of river ice during the winter season

  18. Rocks Can Wow? Yes, Rocks Can Wow!

    Science.gov (United States)

    Hardman, Sally; Luke, Sue

    2016-01-01

    Rocks and fossils appear in the National Curriculum of England science programmes of study for children in year 3 (ages 7-8). A frequently asked question is "How do you make the classification of rocks engaging?" In response to this request from a school, a set of interactive activities was designed and organised by tutors and students…

  19. Thermal characterization of organic matter along a (hypothetical) coalification gradient

    Science.gov (United States)

    Cavallo, Ornella; Provenzano, Maria Rosaria; Zaccone, Claudio

    2017-04-01

    Geochemical transformations of organic carbon (C) in aquatic and terrestrial ecosystems are important starting points for genesis of peats, brown coals and other coal precursors. The humification process plays a key role in biogeochemical transformations of organic C and, as a result, in the first stages of coal precursors formation. Thermal analysis was used by Schnitzer and other scientists since 1950-1960s, in order to investigate the stability of several organic materials of industrial value including peat and coal. What soil scientists found was the general occurrence of two exothermic peaks (exotherm 1 and 2) due to decomposition and combustion reactions of organic compounds having different thermal stability and, consequently, different degree of humification. Thermogravimetric analysis (TG) was carried out on different samples reproducing a "hypothetical" coalification gradient as follows: peat (IHSS Pahokee peat standard), fulvic acid (FA), a peat humic acid (HA), leonardite (IHSS Gascoyne standard) and charcoal. An aliquot of about 20 mg of each sample was heated in a ceramic crucible from 50 to 850˚ C at 30˚ C min-1, at a gas flow rate of 30 mL min-1 using a PerkinElmer TGA4000 thermobalance. Samples were analysed both under nitrogen and under synthetic air. All analyses were carried out in triplicate and the average coefficient of variation was exothermic mass loss has occurred (TG-T50) was also calculated. Preliminary results obtained from TG analysis under air showed that WL2/WL1 ratio was lower for the FA sample and higher for leonardite and charcoal, following the order FA

  20. Monitoring the sedimentary carbon in an artificially disturbed deep-sea sedimentary environment

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Khadge, N.H.; Nabar, S.; Raghukumar, C.; Ingole, B.S.; Valsangkar, A.B.; Sharma, R.; Srinivas, K.

    tonnes of sedimentary organic carbon (C sub(org)) was resuspended into the water column during a 9-day experiment. The majority of the sediment cores from within the disturbed area and areas towards the south showed a approx. 30% increase in C sub...

  1. Application of the Scoping of Options and Analyzing Risk Model (SOAR) in the Modeling of Radionuclide Movement and Dose Calculation for a Hypothetical Deep Geological Repository for Nuclear Fuel Wastes

    Science.gov (United States)

    Lei, S.; Osborne, P.

    2016-12-01

    The Scoping of Options and Analyzing Risk (SOAR) model was developed by the U.S. Nuclear Regulatory Commission staff to assist in their evaluation of potential high-level radioactive waste disposal options. It is a 1-D contaminant transport code that contains a biosphere module to calculate mass fluxes and radiation dose to humans. As part of the Canadian Nuclear Safety Commission (CNSC)'s Coordinated Assessment Program to assist with the review of proposals for deep geological repositories (DGR's) for nuclear fuel wastes, CNSC conducted a research project to find out whether SOAR can be used by CNSC staff as an independent scoping tool to assist review of proponents' submissions related to safety assessment for DGRs. In the research, SOAR was applied to the post-closure safety assessment for a hypothetical DGR in sedimentary rock, as described in the 5th Case Study report by the Nuclear Waste Management Organization (NWMO) of Canada (2011). The report contains, among others, modeling of transport and releases of radionuclides at various locations within the geosphere and the radiation dose to humans over a period of one million years. One aspect covered was 1-D modeling of various scenarios and sensitivity cases with both deterministic and probabilistic approaches using SYVAC3-CC4, which stands for Systems Variability Analysis Code (generation 3, Canadian Concept generation 4), developed by Atomic Energy of Canada Limited (Kitson et al., 2000). Radionuclide fluxes and radiation dose to the humans calculated using SOAR were compared with that from NWMO's modeling. Overall, the results from the two models were similar, although SOAR gave lower mass fluxes and peak dose, mainly due to differences in modeling the waste package configurations. Sensitivity analyses indicate that both models are most sensitive to the diffusion coefficient of the geological media. The research leads to the conclusion that SOAR is a robust, user friendly, and flexible scoping tool that

  2. Explaining the discrepancy between intentions and actions: the case of hypothetical bias in contingent valuation

    Science.gov (United States)

    Icek Ajzen; Thomas C. Brown; Franklin Carvajal

    2004-01-01

    An experiment was designed to account for intention-behavior discrepancies by applying the theory of planned behavior to contingent valuation. College students (N = 160) voted in hypothetical and real payment referenda to contribute $8 to a scholarship fund. Overestimates of willingness to pay in the hypothetical referendum could not be attributed to moderately...

  3. Combining aptamers and in silico interaction studies to decipher the function of hypothetical proteins

    DEFF Research Database (Denmark)

    Suravajhala, Prashanth; Burri, Harsha Vardhan Reddy; Heiskanen, Arto

    2014-01-01

    We present the potential role of aptamers in elucidating the function of hypothetical proteins, as well as the possibilities provided by bioinformatics for establishing a benchmark for aptamer-protein prediction methods. With these future perspectives, the role of hypothetical proteins as target...

  4. Using respondent uncertainty to mitigate hypothetical bias in a stated choice experiment

    Science.gov (United States)

    Richard C. Ready; Patricia A. Champ; Jennifer L. Lawton

    2010-01-01

    In a choice experiment study, willingness to pay for a public good estimated from hypothetical choices was three times as large as willingness to pay estimated from choices requiring actual payment. This hypothetical bias was related to the stated level of certainty of respondents. We develop protocols to measure respondent certainty in the context of a choice...

  5. 47 CFR 69.609 - End User Common Line hypothetical net balances.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false End User Common Line hypothetical net balances... SERVICES (CONTINUED) ACCESS CHARGES Exchange Carrier Association § 69.609 End User Common Line hypothetical net balances. (a) If the company does not participate in the association tariff for such element, the...

  6. Adolescents' explicit and implicit evaluations of hypothetical and actual peers with different bullying participant roles.

    Science.gov (United States)

    Pouwels, J Loes; Lansu, Tessa A M; Cillessen, Antonius H N

    2017-07-01

    This study examined how adolescents evaluate bullying at three levels of specificity: (a) the general concept of bullying, (b) hypothetical peers in different bullying participant roles, and (c) actual peers in different bullying participant roles. Participants were 163 predominantly ethnic majority adolescents in The Netherlands (58% girls; M age =16.34years, SD=0.79). For the hypothetical peers, we examined adolescents' explicit evaluations as well as their implicit evaluations. Adolescents evaluated the general concept of bullying negatively. Adolescents' explicit evaluations of hypothetical and actual peers in the bullying roles depended on their own role, but adolescents' implicit evaluations of hypothetical peers did not. Adolescents' explicit evaluations of hypothetical peers and actual peers were different. Hypothetical bullies were evaluated negatively by all classmates, whereas hypothetical victims were evaluated relatively positively compared with the other roles. However, when adolescents evaluated their actual classmates, the differences between bullies and the other roles were smaller, whereas victims were evaluated the most negatively of all roles. Further research should take into account that adolescents' evaluations of hypothetical peers differ from their evaluations of actual peers. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Can a Repeated Opt-Out Reminder remove hypothetical bias in discrete choice experiments?

    DEFF Research Database (Denmark)

    Alemu, Mohammed Hussen; Olsen, Søren Bøye

    hypothetical bias in stated DCE. The data originates from a field experiment concerning consumer preferences for a novel food product made from cricket flour. Utilizing a between-subject design with three treatments, we find significantly higher marginal willingness to pay values in hypothetical than...

  8. Geothermal resources of California sedimentary basins

    Science.gov (United States)

    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 (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.

  9. Rock slope design guide.

    Science.gov (United States)

    2011-04-01

    This Manual is intended to provide guidance for the design of rock cut slopes, rockfall catchment, and : rockfall controls. Recommendations presented in this manual are based on research presented in Shakoor : and Admassu (2010) entitled Rock Slop...

  10. The Rock Cycle

    Science.gov (United States)

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  11. Discussions on the sedimentary-tectonic event and tectonic setting of the North Tarim Basin in Cryogenian-Cambrian

    Science.gov (United States)

    Zhou, X. B.; Li, J. H.; Li, W. S.

    2012-04-01

    Across the Tarim Basin, limited surface outcrops of Cryogenian to Cambrian sedimentary succession are completely exposed in the vicinity of Aksu area(Northwest Tarim), Kuruktag(Northeast Tarim)and Southwest Tarim, thus provides a unique, well preserved and accessible means by which to study the early development of the north Tarim Basin. Based on the field geological investigation in the northwestern and northeastern of Tarim Basin, with the referencing of paleomagnetism mapping and previous research, basin evolution process in Cryogenian-Cambrian is discussed according to sedimentary-tectonic event and other evidences. The major lithological types of Cryogenian-Cambrian system in Northeast Tarim are: tillite, clastic rocks(rich in organic matter) and carbonate ,with interbeds of volcanic rocks while in Northwest Tarim, the calstic rocks and carbonate are the common rock type, with tillite and volcanic interbeds in a small amount. The north margin of Tarim Block, which was a part of Rodinia supercontinent, neighboring the northwestern margin of Australia, was deeply rifted in Cryogenian-Ediacaran and developed into two rifts in the northwestern and northeastern margin, while formed a thick layer of the rift-passive margin deposits and the layer in the northwestern rift was not completely developed as the northeastern. The deepest rift-passive magin sediment which can be observed is Cryogenian-Middle Ordovician strata, and the period can be divided into Cryogenian faulted period (supercontinent rifting stage) and Ediacaran-Middle Ordovician subsidence period (plate drifting stage).

  12. A global database for the compilation and assessment of Holocene sedimentary palaeomagnetic records

    Science.gov (United States)

    Brown, M. C.; Donadini, F.; Korte, M.; Frank, U.; Nilsson, A.

    2012-04-01

    Global reconstructions of the Holocene palaeomagnetic field can provide powerful information about the geodynamo process and can constrain geomagnetic shielding, important for our understanding of the interaction between the geomagnetic field and cosmogenic nuclide production. Coherent structure is evident in these reconstructions and this has significant implications for controls on the geodynamo. However, the resolution and reliability of current models are limited by: 1) the restricted global coverage of sites, with data especially lacking in the southern hemisphere; 2) the low precision of some magnetic data and independent dates; and 3) an incomplete assessment of data quality. Improving these aspects for sedimentary records is particularly important as loosely constrained sedimentary data strongly influence the model output from spherical harmonic reconstructions of the Holocene geomagnetic field (e.g., differences between CALS3k.3 and CALS3k.4). In addition, the current SECRV00 database lacks data from the most recent sedimentary studies and a number of older studies. We present our current effort to improve the number of studies included in the CALSxk model series and our attempts to assess data quality. In addition, we show the design of a new database for global sedimentary data covering the last 10 ka, which we have implemented as an extension to the GEOMAGIA50 database. Our aim is two-fold: 1) to transparently catalogue all available sedimentary data for the Holocene, so the broader scientific community can access a range of information related to specific cores; and 2) to design a database with the functionally to select palaeomagnetic data based upon parameters that reflect the quality of the data. To make accurate assessments of data quality it is necessary to determine palaeomagnetic, rock magnetic, mineralogical, sedimentary, environmental and chronological parameters that may influence the fidelity of the record. We show these selected parameters

  13. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  14. Activation of diffuse discontinuities and folding of sedimentary layers

    Science.gov (United States)

    Guiton, Martin L. E.; Leroy, Yves M.; Sassi, William

    2003-04-01

    Folding of sedimentary layers is often accommodated by the opening or sliding of inherited and new discontinuities which are assumed here to be diffuse so that a continuum description applies at the fold scale. The rock rheology is then described with an elastoplasticity model for which the permanent deformation is of simple shear (sliding) or dilation (opening) with respect to specific orientations of the new or inherited diffuse discontinuities. To illustrate the relation between folding and activation of diffuse discontinuities, a three-dimensional layer under compression in the two horizontal directions and sustaining the overburden lithostatic pressure is studied. Cylindrical buckling occurs either before (elastic) or after the diffuse discontinuities have been activated. If buckling is elastic, inherited vertical discontinuities, striking obliquely to the fold geometrical axes, are activated in a sliding mode in the outer arc, leading to a rotation of the principal stress directions. Opening is then detected across new vertical planes striking obliquely to the fold axis. The activation of inherited or new vertical discontinuities can be suppressed if sliding takes place along weak bedding interfaces. Alternatively, early and homogeneous layer-parallel shortening, marked by a reverse fault mode, drastically reduces the critical buckling load compared to the Euler load and modifies the final geometry of buckling which is then more of a circular dome shape. The switching in buckling mode results in the fold limbs in a change from the early reverse fault to a strike-slip fault sliding and to opening across diffuse planes oriented consistently with the final circular structure.

  15. Influence of pressure gradients and fracturing in oil field rocks on ...

    African Journals Online (AJOL)

    Natural fractures formed as joint sets in shales and carbonate rocks are also good reservoirs for hydrocarbon accumulation. Fracturing at depth can also be effected artificially by creating pressure gradients by means of fluid. injection. Problems associated with drilling oil and gas wells in over-pressured sedimentary basins ...

  16. Deep sedimentary structure model beneath the Osaka plain; Osaka heiya ni okeru shinbu chika kozo no model ka

    Energy Technology Data Exchange (ETDEWEB)

    Miyakoshi, K.; Kagawa, T.; Echigo, T. [Osaka Soil Test, Osaka (Japan)

    1997-05-27

    Restructuring was carried out on a sedimentary basin structure model of the Osaka plain including Osaka Bay by using newly obtained underground structural data. After the Hygoken-nanbu Earthquake of 1995, a large number of underground structure investigations have been performed in Osaka Bay and urban areas of Kobe and Osaka. However, very few surveys have been done in areas peripheral to Osaka Prefecture, such as the Ikoma area. Therefore, an attempt has been made to increase the number of measuring points to acquire underground structural data of these areas. Estimation of basic rock depths has utilized the dominant cycles in H/V spectra obtained from micro vibration survey, and good correlation of the base rock depths derived by a refraction exploration and a deep-bed boring investigation. With regard to bed division and P- and S- wave velocities in sedimentary beds in the Osaka sedimentary basin, an underground structure model was prepared, which was divided into four beds according to the refraction exploration and the micro vibration investigation. Data obtained by using this model agreed well with depth data acquired from physical exploration and other types of investigations. However, no good agreement was recognized in the data for such areas where the basic depth changes abruptly as the Rokko fault and the Osaka bay fault. 6 refs., 8 figs., 2 tabs.

  17. Hawai'i and Gale Crater: A Mars Analogue Study of Igneous, Sedimentary, Weathering, and Alteration Trends in Geochemistry

    Science.gov (United States)

    Berger, J. A.; Flemming, R. L.; Schmidt, M. E.; Gellert, R.; Morris, R. V.; Ming, D. W.

    2017-01-01

    Sedimentary rocks in Gale Crater on Mars indicate a varied provenance with a range of alteration and weathering [1, 2]. Geochemical trends identified in basaltic and alkalic sedimentary rocks by the Alpha Particle X-ray Spectrometer (APXS) on the Mars rover Curiosity represent a complex interplay of igneous, sedimentary, weathering, and alteration processes. Assessing the relative importance of these processes is challenging with unknown compositions for parent sediment sources and with the constraints provided by Curiosity's instruments. We therefore look to Mars analogues on Earth where higher-resolution analyses and geologic context can constrain interpretations of Gale Crater geochemical observations. We selected Maunakea (AKA Mauna Kea) and Kohala volcanoes, Hawai'i, for an analogue study because they are capped by post-shield transitional basalts and alkalic lavas (hawaiites, mugearites) with compositions similar to Gale Crater [1, 3]. Our aim was to characterize Hawaiian geochemical trends associated with igneous processes, sediment transport, weathering, and alteration. Here, we present initial results and discuss implications for selected trends observed by APXS in Gale Crater.

  18. BOLD responses in reward regions to hypothetical and imaginary monetary rewards.

    Science.gov (United States)

    Miyapuram, Krishna P; Tobler, Philippe N; Gregorios-Pippas, Lucy; Schultz, Wolfram

    2012-01-16

    Monetary rewards are uniquely human. Because money is easy to quantify and present visually, it is the reward of choice for most fMRI studies, even though it cannot be handed over to participants inside the scanner. A typical fMRI study requires hundreds of trials and thus small amounts of monetary rewards per trial (e.g. 5p) if all trials are to be treated equally. However, small payoffs can have detrimental effects on performance due to their limited buying power. Hypothetical monetary rewards can overcome the limitations of smaller monetary rewards but it is less well known whether predictors of hypothetical rewards activate reward regions. In two experiments, visual stimuli were associated with hypothetical monetary rewards. In Experiment 1, we used stimuli predicting either visually presented or imagined hypothetical monetary rewards, together with non-rewarding control pictures. Activations to reward predictive stimuli occurred in reward regions, namely the medial orbitofrontal cortex and midbrain. In Experiment 2, we parametrically varied the amount of visually presented hypothetical monetary reward keeping constant the amount of actually received reward. Graded activation in midbrain was observed to stimuli predicting increasing hypothetical rewards. The results demonstrate the efficacy of using hypothetical monetary rewards in fMRI studies. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Measurement of unsaturated hydraulic properties and evaluation of property-transfer models for deep sedimentary interbeds, Idaho National Laboratory, Idaho

    Science.gov (United States)

    Perkins, Kimberlie; Johnson, Brittany D.; Mirus, Benjamin B.

    2014-01-01

    Operations at the Idaho National Laboratory (INL) have the potential to contaminate the underlying Eastern Snake River Plain (ESRP) aquifer. Methods to quantitatively characterize unsaturated flow and recharge to the ESRP aquifer are needed to inform water-resources management decisions at INL. In particular, hydraulic properties are needed to parameterize distributed hydrologic models of unsaturated flow and transport at INL, but these properties are often difficult and costly to obtain for large areas. The unsaturated zone overlying the ESRP aquifer consists of alternating sequences of thick fractured volcanic rocks that can rapidly transmit water flow and thinner sedimentary interbeds that transmit water much more slowly. Consequently, the sedimentary interbeds are of considerable interest because they primarily restrict the vertical movement of water through the unsaturated zone. Previous efforts by the U.S. Geological Survey (USGS) have included extensive laboratory characterization of the sedimentary interbeds and regression analyses to develop property-transfer models, which relate readily available physical properties of the sedimentary interbeds (bulk density, median particle diameter, and uniformity coefficient) to water retention and unsaturated hydraulic conductivity curves.

  20. Radiogenic heat production of crustal rocks: An assessment based on geochemical data

    Science.gov (United States)

    Wollenberg, H. A.; Smith, A. R.

    A survey of the geochemical literature and unpublished data has resulted in the classification of U, Th, and K concentrations by rock type. Over 2500 data entries have been compiled, permitting calculation of their radiogenic heat production. In the igneous rocks mean heat production ranges from highs of 12-20 heat production units (HPU: µWm-3) in some peralkaline intrusives, through ˜ 4 HPU in acidic, ˜ 2 in intermediate, and ˜ 1 in basic rocks, to a low of 0.3 HPU in ultramafic rocks. Siliceous clastic rocks generally have greater heat production (2 to 4 HPU) than do chemical sedimentary rocks, including the carbonates (0.4 to 2 HPU). The heat production of metamorphic rocks generally depends on the radioelement contents of their igneous and sedimentary predecessors, modified by metamorphic processes. Based on estimates of the proportion of the continental crust that specific rock types occupy, the weighted mean radiogenic heat production of the upper continental crust estimated from this data base is ˜ 3 HPU.

  1. Iron speciation in bleached rocks by hydrocarbon leaching in Dushanzi Mud Volcano, NW China

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, G D [Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000 (China); Fu, B H; Matsuo, M [Key Laboratory of Earth' s Deep Interior, Institute of Geology and Geography, Chinese Academy of Sciences, Beijing 100029 (China); Kuno, A, E-mail: gdzhuk@hotmail.co [Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902 (Japan)

    2010-03-01

    Mud volcano is a typical petroleum leaching system, which normally result in bleaching effect to surrounding rocks. The result of Moessbauer spectroscopy of rock samples collected from the Dushanzi mud volcano system revealed clear variations in iron species. Compared to the unbleached reddish sedimentary rocks, the bleached rocks are dominated by reducing iron species such as paramagnetic ferrous iron (para-Fe{sup 2+}), ferrous iron in siderite (sid-Fe{sup 2+}), sulphide and pyrite (pyr-Fe{sup 2+}) whereas the original reddish rock is enriched in ferric iron including iron in hematite (hem-Fe{sup 3+}) and paramagnetic ferric iron (para-Fe{sup 3+}). A reduction of ferric iron species and hydrolysis of iron along with oxidation of hydrocarbons should be one of the main processes along bleaching by hydrocarbons to rocks.

  2. [Science in the crosshairs of enlightenment. Significance of hypothetical thinking].

    Science.gov (United States)

    Wieland, Wolfgang

    2011-01-01

    To further the enlightenment primarily or even only by means of science was the hope of most representatives of the movement of the enlightenment which gave its name to a whole period of European cultural history. Only a few of its representatives, like Montesquieu and Rousseau, doubted for good reasons, whether and how the goals of the enlightenment can be reached at all by the means of science alone. In his Discours préliminaires to the Encyclopédie D'Alembert still wanted to limit science proper to the narrower field of those kinds of research which were strictly based on observations and calculations alone. In this way he remained committed to Descartes' ideal method of receiving authentic knowledge only by deduction from evident axioms or fundamental theorems. Pascal's casual discovery of the calculation of probabilities allowed to apply mathematics on the hidden laws of the apparent casualties of the human life world. Bacon's project of empirical science as a rational and methodological art of conducting experiments could replace the methodological ideal of science more geometrico. Lichtenberg's refined sensibility for the subjunctive linguistic forms of hypothetical thinking indicates a new understanding of inventing and testing hypotheses as the two most important methods of the experimental sciences when compared to the formal sciences of logic and mathematics. Whoever is studying the history of science of modern times in the cross wire of the enlightenment, will realize soon that science has always been in need of being illuminated about its own chances, risks and side effects. The project of enlightenment through science had to be complemented by the project of an enlightenment about science right from its beginning. Because of the implicit risks and side effects the project of enlightenment has to be enlightenment despite of science and because of science. On the one hand, as a special form of human practice the sciences are directed towards

  3. Sedimentary basins and petroleum occurrences, Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, M.C.; Page, M.M.; Penttila, W.C. (Exploration Associates International of Texas, Inc., Houston (United States))

    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.

  4. Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale Crater, Mars

    NARCIS (Netherlands)

    Ming, D.W.; Archer Jr., P.D.; Glavin, D.P.; Eigenbrode, J.L.; Franz, H.B.; Sutter, B.; Brunner, A.E.; Stern, J.C.; Freissinet, C.; McAdam, A.C.; Mahaffy, P.R.; Cabane, M.; Coll, P.; Campbell, J.L.; Atreya, S.K.; Niles, P.B.; Bell III, J.F.; Bish, D.L.; Brinckerhoff, W.B.; Buch, A.; Conrad, P.G.; Des Marais, D.J.; Ehlmann, B.L.; Fairén, A.G.; Farley, K.; Flesch, G.J.; Francois, P.; Gellert, R.; Grant, J.A.; Grotzinger, J.P.; Gupta, S.; Herkenhoff, K.E.; Hurowitz, J.A.; Leshin, L.A.; Lewis, K.W.; McLennan, S.M.; Miller, K.E.; Moersch, J.; Morris, R.V.; Navarro-González, R.; Pavlov, A.A.; Perrett, G.M.; Pradler, I.; Squyres, S.W.; Summons, R.E.; Steele, A.; Stolper, E.M.; Sumner, D.Y.; Szopa, C.; Teinturier, S.; Trainer, M.G.; Treiman, A.H.; Vaniman, D.T.; Vasavada, A.R.; Webster, C.R.; Wray, J.J.; Yingst, R.A.; MSL Science Team, the|info:eu-repo/dai/nl/292012217

    2014-01-01

    H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and

  5. An atlas of Mars sedimentary rocks as seen by HiRISE

    Science.gov (United States)

    Beyer, Ross; Stack, Kathryn M.; Griffes, Jennifer L.; Milliken, Ralph E.; Herkenhoff, Ken E.; Byrne, Shane; Holt, John W.; Grotzinger, John P.; Grotzinger, John P.; Milliken, Ralph E.

    2012-01-01

    Images of distant and unknown places have long stimulated the imaginations of both explorers and scientists. The atlas of photographs collected during the Hayden (1872) expedition to the Yellowstone region was essential to its successful advocacy and selection in 1872 as America's ӿrst national park. Photographer William Henry Jackson of the Hayden expedition captured the public's imagination and support, returning home with a treasure of images that conӿrmed the existence of western landmarks previously regarded as gloriӿed myths: the Grand Tetons, Old Faithful, and strange pools of boiling hot mud. Fifty years later, photographer Ansel Adams began his long legacy of providing the public with compilations of iconic images of natural wonders that many only see in prints.

  6. Origin of coffinite in sedimentary rocks by a sequential adsorption-reduction mechanism.

    Science.gov (United States)

    Goldhaber, M.B.; Hemingway, B.S.; Mohagheghi, A.; Reynolds, R.L.; Northrop, H.R.

    1987-01-01

    Coffinite is the dominant ore mineral in the V-U ores of the Tony-M mine in the Henry Mts mineral belt of the Colorado Plateau. This orebody was formed at a density-stratified solution interface between uranyl-ion-bearing meteoric water and a saline fluid which was locally reducing. The localization of U at this solution interface occurred by adsorption onto the surfaces of detrital minerals, this adsorption being related to the pH difference between the two fluids. Experimental evidence is presented showing that the adsorption facilitated the reduction of uranium to U(IV). This adsorbed, reduced uranium bonded with aqueous silica in the ore zone to form coffinite. The high concentration of silica (as a monomeric species) in the ore-forming solution stabilized coffinite in preference to uraninite.-R.A.H.

  7. From ooze to sedimentary rock, the first diagenetic processes affecting the chalk of eastern Denmark

    DEFF Research Database (Denmark)

    Moreau, Julien; Boussaha, Myriam; Nielsen, Lars

    processes operating in the chalk sediments at widely different scales into a single diagenetic model: At Stevns the chalk is affected by an extensive polygonal fault system which is expressed in onshore and offshore seismic profiles. Smaller scale contractional features like deformation bands (hairline...... strongly affect reservoir properties of the chalk both by establishing compartments and vertical connections. A better understanding of these reservoir modifications will be critical for improving the predictive capability of models describing the behaviour of drinking water and hydrocarbons hosted...

  8. Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars

    Science.gov (United States)

    Ming, D. W.; Archer, P.D.; Glavin, D.P.; Eigenbrode, J.L.; Franz, H.B.; Sutter, B.; Brunner, A.E.; Stern, J.C.; Freissinet, C.; McAdam, A.C.; Mahaffy, P.R.; Cabane, M.; Coll, P.; Campbell, J.L.; Atreya, S.K.; Niles, P.B.; Bell, J.F.; Bish, D.L.; Brinckerhoff, W.B.; Buch, A.; Conrad, P.G.; Des Marais, D.J.; Ehlmann, B.L.; Fairén, A.G.; Farley, K.; Flesch, G.J.; Francois, P.; Gellert, Ralf; Grant, J. A.; Grotzinger, J.P.; Gupta, S.; Herkenhoff, K. E.; Hurowitz, J.A.; Leshin, L.A.; Lewis, K.W.; McLennan, S.M.; Miller, Karl E.; Moersch, J.; Morris, R.V.; Navarro- González, R.; Pavlov, A.A.; Perrett, G.M.; Pradler, I.; Squyres, S. W.; Summons, Roger E.; Steele, A.; Stolper, E.M.; Sumner, D.Y.; Szopa, C.; Teinturier, S.; Trainer, M.G.; Treiman, A.H.; Vaniman, D.T.; Vasavada, A.R.; Webster, C.R.; Wray, J.J.; Yingst, R.A.

    2014-01-01

    H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.

  9. Thermodynamics and kinetics of reactions involving vanadium in natural systems: Accumulation of vanadium in sedimentary rocks

    Science.gov (United States)

    Wanty, R.B.; Goldhaber, M.B.

    1992-01-01

    A critical review of thermodynamic data for aqueous and solid V species is presented to evaluate dissolution, transport, and precipitation of V under natural conditions. Emphasis is given to results of experimental studies of V chemistry, especially those for which the experimental conditions are near those found in nature. Where possible, data are obtained for or corrected to the reference conditions of 298.15K, 1 atm (1.01325 bar) and zero ionic strength. Vanadium [IV] (VIV) and vanadium[V] (VV) are the most soluble forms of V in nature, and their complexes with fluoride, sulfate, and oxalate may act to increase V solubility under oxidizing conditions. Because redox behavior is of fundamental importance to understanding natural V chemistry, the kinetics of reduction of VIV to VIII H2S were studied. Although H2S is predicted from thermodynamic data to be capable of reducing VIV to VIII, this reaction has not been demonstrated experimentally. Experiments were carried out under conditions of temperature (45??C), pH (3.6-6.8), ionic strength (0.05-0.1 m), and V concentrations (9.8-240 ??molar) likely to be found in nature. Because the reaction is very slow, H2S concentrations in excess of natural conditions were used (8.1 ?? 10-4 to 0.41 atm). The results show that VIV is reduced to VIII under a variety of conditions. The rate increases with increasing pH, but is not appreciably affected by ionic strength (as represented by the concentration of KCl, which was used as the supporting electrolyte in all cases). Prior to initiation of the reaction, there is an induction period, the length of which increases with increasing KCl concentration or decreasing pH. Attempts to model the reaction mechanism by numerical methods have failed to produce a satisfying fit of the results, indicating partial reaction orders, a complex mechanism, or involvement of a variety of intermediate species. The results of the thermodynamic and kinetic studies were applied to understanding the genesis of V deposits such as those commonly found on the Colorado Plateau. Vanadium in these sandstone-hosted deposits is present mostly in the reduced oxidation state, VIII. Because of the insolubility of VIII oxyhydroxides, it is likely that a more oxidized form of V (either [IV] or [V]) was transported to the site of mineralization, and that the V was reduced in situ and subsequently precipitated. A probable reductant is hydrogen sulfide; the presence of pyrite cogenetic with the V minerals documents the presence of H2S during mineralization. The experiments described here show that H2S could have reduced VIV to V III, and thus led to the formation of these deposits. ?? 1992.

  10. Relationships between Lu-Hf and Sm-Nd isotopic systems in the global sedimentary system

    Science.gov (United States)

    Vervoort, Jeff D.; Patchett, P. Jonathan; Blichert-Toft, Janne; Albarède, Francis

    1999-04-01

    We report new Hf (and Nd) data for more than 100 sedimentary samples, recent to Archean in age, from a wide range of depositional environments. These data document the behavior of Lu-Hf and Sm-Nd isotopic systems in the global sedimentary system. In conjunction with existing data for mantle-derived rocks, we now have reasonable constraints on coupled Hf-Nd isotopic behavior in the crust and mantle. Lu/Hf and Hf isotopic compositions are strongly fractionated between muds and sands in passive margin sediments due to concentration of low Lu/Hf, low 176Hf/177Hf, Hf-rich zircons in mature sands. In active margin settings, Lu-Hf fractionation due to the `zircon effect' is minor due to the less weathered and more juvenile character of the sediments. Nd isotopic compositions are not highly fractionated by sedimentary sorting because heavy minerals, also rich in REEs, do not fractionate Sm-Nd efficiently. The lack of a large and systematic fractionation at active margins means that no significant Hf-Nd decoupling occurs here. This is important because sediments at active margins are the most likely to be recycled to the mantle. Hf-Nd isotopic data for all terrestrial samples fall along a single coherent trend (ɛHf=1.36ɛNd+2.95) which we call the `terrestrial array'. This array is composed of two complementary components: a mantle array (ɛHf=1.33ɛNd+3.19, defined by all oceanic basalts; and a crustal array (ɛHf=1.34ɛNd+2.82), defined by sediments, continental basalts, granitoids, and juvenile crustal rocks. The similarity of the crustal and mantle arrays indicates that no large-scale Hf-Nd decoupling occurs between the crust and mantle. The coherency of the terrestrial Hf-Nd array implies mixing within the mantle, due to stirring processes, and also within the crust, due to homogenization by collective sedimentary processes. In addition, tight Hf-Nd covariation may also imply that efficient crust to mantle recycling has modulated isotopic correlation in the silicate

  11. TECTONIC ZONING OF THE SEDIMENTARY COVER OF THE SEA OF OKHOTSK BASED ON LITHOPHYSICAL, STRUCTURAL AND STRUCTURAL-LITHOPHYSICAL INDICATORS

    Directory of Open Access Journals (Sweden)

    V. P. Semakin

    2014-01-01

    Full Text Available In terms of tectonics, the Sea of Okhotsk (Fig.1 is the epi-Mesozoic Okhotsk plate comprising the heterogeneous basement that is mainly pre-Cenozoic (the lower structural stage and the sedimentary cover that is mainly represented by the Paleogenic-Neogenic-Quaternary deposits with the Upper Cretaceous sedimentary rocks observed locally without a visible hiatus (the upper structural stage.Results of tectonic zoning of the sedimentary cover based on  lithophysical indicators (Fig. 2 are represented in the format of maps showing lithophysical complexes (LC within the limits of four regional seismo-stratigraphic complexes/structural layers (RSSC I-IV corresponding to the following time intervals: the pre-Oligocene К2-P1-2 (RSSC I, the Oligocene – Lower Miocene P3-N11 (RSSC II, the Lower-Mid Miocene N11-2 (RSSC III, and the Upper Miocene – Pliocene N13-N2 (RSSC IV. Diverse lithological-facies associations composing the RSSCs are grouped into the following lithophysical complexes (LC: 1 - coal-bearing silty-clayey-sandy terrigenous, 2 - sandy-silty-clayey terrigenous, 3 - silty-clayey-siliceous, and 4 - sandy-silty-clayey volcanic [Sergeyev, 2006].Tectonic zoning of the sedimentary cover based on structural indicators is carried out with reference to the sediment-thickness map [Sergeyev, 2006], including a significantly revised segment showing the area of the Deryugin basin [Semakin, Kochergin, 2013]. Results of such zoning are represented in the format of a structural-tectonic map (Fig. 3 showing orientations and morphology of the structural elements of the sedimentary cover, the thickness of the sedimentary cover, and amplitudes of relative uplifts and troughs.With reference to the structural-tectonic map (see Fig 3, the structural elements of different orders are grouped by their sizes, spatial positions and orientations and thus comprise tectonic sistems (Fig. 4, structural zones (Fig. 5 that unclude relative uplifts and troughs that are

  12. Positive anomalous concentrations of Pb in some gabbroic rocks of Afikpo basin southeastern Nigeria.

    Science.gov (United States)

    Onwualu-John, J N

    2016-08-01

    Gabbroic rocks have intruded the sedimentary sequence at Ameta in Afikpo basin southeastern Nigeria. Petrographic and geochemical features of the rocks were studied in order to evaluate their genetic and geotectonic history. The petrographic results show that the rocks contain plagioclase, olivine, pyroxene, biotite, iron oxide, and traces of quartz in three samples. Major element characteristics show that the rocks are subalkaline. In addition, the rocks have geochemical characteristics similar to basaltic andesites. The trace elements results show inconsistent concentrations of high field strength elements (Zr, Nb, Th, Ta), moderate enrichment of large-ion lithophile elements (Rb, Sr, Ba) and low concentrations of Ni and Cr. Rare earth element results show that the rocks are characterized by enrichment of light rare earth elements, middle rare earth elements enrichment, and depletion of heavy rare earth elements with slight positive europium anomalies. Zinc concentrations are within the normal range in basaltic rocks. There are extremely high concentrations of Pb in three of the rock samples. The high Pb concentrations in some of these rocks could be as a result of last episodes of magmatic crystallization. The rocks intruded the Asu River Group; organic components in the sedimentary sequence probably contain Pb which has been assimilated into the magma at the evolutionary stage of the magma. Weathering of some rocks that contain galena could lead to an increase in the concentration of lead in the gabbroic rocks, especially when the migration and crystallization of magma take place in an aqueous environment. Nevertheless, high concentration of lead is hazardous to health and environment.

  13. {sup 210}Pb dating of sediments from the central and the northern Adriatic Sea: The deposition and preservation of sedimentary organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, T.; Fowler, S.; Miquel, J.C.; La Rosa, J.

    1996-04-01

    A central goal of the ELNA project is to assess the carbon assimilation capacity of the Northern Adriatic Sea. This requires fundamental quantitative information on budgets and sinks of organic carbon. Any change in carbon production in the water column should be reflected in the underlying sediments. Moreover, the fraction of particulate organic carbon reaching the sea floor which is subsequently preserved in the sediment will be strongly coupled to sediment accumulation and mixing. In this study a series of box cores were collected in order to characterize a hypothetical eutrophication gradient extending from the Po River outflow region in the north down to the shallow meso-Adriatic depression (Jabuka Pit). The main tasks assigned to IAEA-MEL were to provide {sup 210}Pb derived sedimentation and dry-mass accumulation rates and to examine the possible correlations between sedimentary processes, the deposition and preservation of sedimentary organic carbon and pelagic primary productivity.

  14. Sulphate rocks as an arena for karst development

    Directory of Open Access Journals (Sweden)

    Andrejchuk V.

    1996-01-01

    Full Text Available The rocks in which karst systems develop are most commonly composed of carbonate sulphate and chloride minerals. The sulphate minerals are quite numerous, but only gypsum and anhydrite form extensive masses in sedimentary sequences. Other minerals, which represent sulphates of K, Mg and Na, normally occur as minor beds (0.1-5.0 m, or as inclusions associated with chloride rocks. However some minerals precipitated in salt-generating basins, such as mirabilite and glauberite (typically formed in the Kara-Bogaz-Gol Gulf, salt lakes of Siberia and in China, form sequences up to 5-10 m thick where karst may develop. Due to the very high solubility of Na -sulphates, karst processes and features occurring in these rocks resemble salt karst. Thus, the term sulphate karst, although not strictly correct, is used mainly to indicate karst developed in gypsum and anhydrite.

  15. MODFLOW-NWT model of a hypothetical stream-aquifer system to assess capture map bias

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A MODFLOW-NWT (version 1.0.9) model of a hypothetical stream-aquifer system is presented for the evaluation and characterization of capture map bias. The...

  16. Explaining the discrepancy between intentions and actions: the case of hypothetical bias in contingent valuation.

    Science.gov (United States)

    Ajzen, Icek; Brown, Thomas C; Carvajal, Franklin

    2004-09-01

    An experiment was designed to account for intention-behavior discrepancies by applying the theory of planned behavior to contingent valuation. College students (N = 160) voted in hypothetical and real payment referenda to contribute $8 to a scholarship fund. Overestimates of willingness to pay in the hypothetical referendum could not be attributed to moderately favorable latent dispositions. Instead, this hypothetical bias was explained by activation of more favorable beliefs and attitudes in the context of a hypothetical rather than a real referendum. A corrective entreaty was found to eliminate this bias by bringing beliefs, attitudes, and intentions in line with those in the real payment situation. As a result, the theory of planned behavior produced more accurate prediction of real payment when participants were exposed to the corrective entreaty.

  17. Mineralogical comparisons of experimental results investigating the biological impacts on rock transport processes.

    Science.gov (United States)

    Wagner, Doris; Milodowski, Antoni E; West, Julia M; Wragg, Joanna; Yoshikawa, Hideki

    2013-08-01

    This study investigates the influence of microbes on fluid transport in sedimentary and igneous host rock environments. It particularly focuses on granodiorite rock (Äspö; Sweden) and mudstone (Horonobe; Japan) that were utilised during laboratory-based column experiments. The results showed that biofilms form on both rock types in low nutrient conditions. Cryogenic scanning electron microscopy showed that the morphology of biofilaments varied from filamentous meshwork (in crushed granodiorite column experiments) to clusters of rod-like cells (fracture surfaces in mudstone). X-ray diffraction analysis of the fine fractions (containment and migration of contaminants.

  18. Provenance and paleo-weathering of Tertiary accretionary prism-forearc sedimentary deposits of the Andaman Archipelago, India

    Science.gov (United States)

    Awasthi, Neeraj

    2017-12-01

    In order to understand the provenance and tectono-sedimentary processes occurring in the Andaman Subduction Zone (ASZ), the Late Cretaceous to Oligocene sedimentary records from the Andaman Islands have been studied. These sedimentary records are considered to have preserved the history of the India-Asia collision, evolution of the Himalayas, climatic development and palaeo-drainage reorganizations on the Indian and Asian plates. About 47 sandstones and mudstones (shales and siltstones) samples were analyzed for whole rock major, trace, and rare earth element compositions. The geochemical results suggest mixing of sediments derived from the mafic igneous sources comprising local ophiolites and volcanic arc of the ASZ and an older Archean to Proterozoic age felsic cratonic source with compositions similar to average granodiorite or upper continental crustal sources. The compositions were dominated by sources of the mafic arc during deposition of the Mithakhari Group, whereas they were controlled by continental sources during deposition of the Andaman Flysch Group. The Hope Town Conglomerate unit of the Mithakhari Group was mainly derived from weathering and erosion of the subaerially exposed local ophiolite thrust sheets, whereas its Namunagarh unit contains significant detritus from volcanic arcs. The Andaman Flysch turbidites were deposited with a greater supply of sediments from first-cycle active continental margin sources probably located in the Tibetan and eastern Myanmar region and recycled quartzose sedimentary sources within the nascent Himalayas. The sediments supplied to both the Mithakhari and the Andaman Flysch Groups were characterized by varying values of CIA, PIA and W. These variable values were either due to non-steady state weathering conditions in the sources or the changing climatic conditions owing to the motion of Indian plate with reference to the equator. The uniformly high CIA and W values in the Andaman Flysch rocks can be related to high

  19. Use of laboratory simulated pyrolysis in tracing the history of sedimentary organic matter

    Science.gov (United States)

    Kaplan, I. R.; Tannenbaum, E.; Huizinga, B. E.

    1986-01-01

    Results from laboratory simulated pyrolyses experiments show that in addition to depth of burial, preservation of kerogen, and hence any morphologic structure in it, is also dependent on the mineral matrix with which it is associated. In the presence of clay minerals, and especially under dry conditions, extractable lipids released during kerogen decomposition are more rapidly destroyed than in the presence of calcite or chert matrices. The result is production of gas, polar bitumen and pyrobitumen and destruction of biomarkers. During such an early reorganization of the kerogen, the biomarker constituents can be destroyed, or unrecognizably altered. The above process of organic residues maturation appears to be inhibited in the presence of water and is significantly reduced where kerogen is hosted in limestones, dolomites or cherts. These minerals have been characteristically found to be the most reliable in yielding morphological fossils and small quantities of extractable bitumen in Archean and Proterozoic rocks. To understand the validity of chemical and morphological fossils, in the early geologic record, it will be necessary to understand the process of kerogen in sedimentary rocks. To test the role of various minerals on the preservation process, kerogen extracted from a variety of rocks has been heated together with montmorillonite, illite and calcite. The kinetics of the process has been monitored and the products quantitatively identified.

  20. Rare earth elements in the sedimentary cycle - A pilot study of the first leg

    Science.gov (United States)

    Basu, A.; Blanchard, D. P.; Brannon, J. C.

    1982-01-01

    The effects of source rock composition and climate on the natural abundances of rare elements (REE) in the first leg of the sedimentary cycle are evaluated using a study with Holocene fluvia sands. The medium grained sand fraction of samples collected from first order streams exclusively draining granitic plutons in Montana (semi-arid), Georgia (humid), and South Carolina (humid) are analyzed. It is found that the REE distribution patterns (but not the total absolute abundances) of the daughter sands are very similar, despite compositional differences between parent plutons. Averages of the three areas are determined to have a La/Lu ratio of about 103, showing a depletion of heavy REE with respect to an average granite (La/Lu = 79) or the composition of North American Shales (La/Lu = 55). However, the Eu/Sm ratio in sands from these areas is about 0.22, which is very close to this ratio in North American Shales (0.21), although the overall REE distribution of these sands is not similar to that of the North American Shales in any way. It is concluded that the major rock type, but neither its minor subdivisions nor the climate, controls the REE distribution patterns in first cycle daughter sands, although the total and the parent rock-normalized abundances of REE in sands from humid areas are much lower than those in sands from arid areas.

  1. Rocks Exposed on Slope in Aram Chaos

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-550, 20 November 2003This spectacular vista of sedimentary rocks outcropping on a slope in Aram Chaos was acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) on 14 November 2003. Dark piles of coarse talus have come down the slopes as these materials continue to erode over time. Note that there are no small meteor impact craters in this image, indicating that erosion of these outcrops has been recent, if not on-going. This area is located near 2.8oS, 20.5oW. The 200 meter scale bar is about 656 feet across. Sunlight illuminates the scene from the lower right.

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

    Directory of Open Access Journals (Sweden)

    Ziliang Liu

    Full Text Available 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

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

    Science.gov (United States)

    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.

  4. Supraglacial rock avalanches and their effect on glacial deposition

    Science.gov (United States)

    Reznichenko, N.; Davies, T. R. H.; Shulmeister, J.; Winkler, S.

    2012-04-01

    Although rock avalanches occur commonly in glaciated valleys, it is only recently that their effects on the regime and final deposits of debris-covered glaciers have been recognized. The supraglacially-emplaced rock avalanche deposits are distinct features on glacial surfaces due to their different sedimentology and greater depth than other debris covers. The metre-scale thickness and large areal extent of these deposits significantly impact the glacier mass balance by preventing ice-surface ablation (Reznichenko et al., 2011). These effects are often neglected in estimating the total change of glacial mass balance and its response to the catastrophic event. A supraglacial rock avalanche deposit can cause a glacier to form a moraine that will not reflect any current climate forcing. It is likely that only larger rock avalanche events (with respect to the size of the glacier) will result in a significant glacial response (e.g. advance or cessation of retreat). However, all supraglacially transported rock avalanche sediment will be recycled into moraines. The climatic signals extracted from the moraine chronologies of such glaciers may consequently have significant errors. The specific sedimentary characteristics of rock avalanche sediment such as agglomerates produced under high stress conditions (Reznichenko et al., in press) can be used to identify moraines that may have been formed from rock avalanche effect. Reznichenko, N.V., Davies, T.R.H. and Alexander, D.J., 2011. Effects of rock avalanches on glacier behaviour and moraine formation. Geomorphology, v. 132, is.3-4, p. 327-338 Reznichenko, N.V., Davies, T.R.H., Shulmeister, J. and Larsen S.H. Accepted. A new technique for identifying rock-avalanche-sourced sediment in moraines and some paleoclimatic implications. Geology.

  5. Probabilistic Rock Slope Engineering.

    Science.gov (United States)

    1984-06-01

    distances or may reflect errors or uncertainties in sample collection and evaluation. 58. Typical variograms for fracture set properties are illustrated... uncertainties in their measurement and estimation imply the probabilistic nature of parameters re- quired for rock slope engineering. Therefore, statistical...strengths of geologic discontinuities and also by the local stress field. Natural variabilities in these rock mass properties and uncertainties in their

  6. Rock Cycle Roulette.

    Science.gov (United States)

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

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

    Science.gov (United States)

    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

  8. Ophiolite Tectonics, Rock Magnetism and Palaeomagnetism, Cyprus

    Science.gov (United States)

    Borradaile, G. J.; Lagroix, F.; Hamilton, T. D.; Trebilcock, D.-A.

    2010-06-01

    Magnetic properties of minerals may be sensitive indicators of provenance. Remanence-bearing minerals (RBM) such as iron-titanium oxides, and matrix-forming minerals such as paramagnetic phyllosilicate or diamagnetic calcite yield different clues to provenance, strain history and tectonics, and are essential supplements for the full interpretation of palaeomagnetic data. Moreover, mineral magnetic properties provide magnetic-petrofabric indicators of tectonic strain, determine the suitability of sites for palaeomagnetism, and permit the restoration of palaeomagnetic vectors in some strained rocks. In the Cretaceous Troodos ophiolite (~88 Ma) magnetic properties are dictated by the relative importance of mafic silicates and largely primary, ophiolite-derived RBM. In its cover of deformed pelagic sedimentary rock, magnetic properties are dictated by the balance of clastic RBM versus matrix calcite and in some cases clay. The two larger Cretaceous ophiolite outcrops (Troodos & Akamas) share a common orientation of their plutonic flow fabrics, determined by magnetic methods. The dike complex shows fabrics indicating plume-like feeders spaced along and perpendicular to the spreading axis, with longevities >0.5 Ma. South of the ophiolite, its Cretaceous-Miocene limestone cover possesses ubiquitous tectonic petrofabrics inferred from anisotropy of magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent susceptibility (AARM). Its foliation and maximum extension dip and plunge gently northward, sub-parallel to a common but previously unreported North-dipping stylolitic cleavage. In well-known localized areas, there are S-vergent thrusts and overturned folds. The S-vergent deformation fabrics are due to Late Miocene (pre-Messinian ~8 Ma) deformation. The structures are geometrically consistent with overthrusting of the Cretaceous Troodos-Akamas ophiolite, and its sedimentary cover, onto the underlying Triassic Mamonia terrane. The northern limit of pre

  9. Testing Urey's carbonate-silicate cycle using the calcium isotopic composition of sedimentary carbonates

    Science.gov (United States)

    Blättler, Clara L.; Higgins, John A.

    2017-12-01

    Carbonate minerals constitute a major component of the sedimentary geological record and an archive of a fraction of the carbon and calcium cycled through the Earth's surface reservoirs for over three billion years. For calcium, carbonate minerals constitute the ultimate sink for almost all calcium liberated during continental and submarine weathering of silicate minerals. This study presents >500 stable isotope ratios of calcium in Precambrian carbonate sediments, both limestones and dolomites, in an attempt to characterize the isotope mass balance of the sedimentary carbonate reservoir through time. The mean of the dataset is indistinguishable from estimates of the calcium isotope ratio of bulk silicate Earth, consistent with the Urey cycle being the dominant mechanism exchanging calcium among surface reservoirs. The variability in bulk sediment calcium isotope ratios within each geological unit does not reflect changes in the global calcium cycle, but rather highlights the importance of local mineralogical and/or diagenetic effects in the carbonate record. This dataset demonstrates the potential for calcium isotope ratios to help assess these local effects, such as the former presence of aragonite, even in rocks with a history of neomorphism and recrystallization. Additionally, 29 calcium isotope measurements are presented from ODP (Ocean Drilling Program) Site 801 that contribute to the characterization of altered oceanic crust as an additional sink for calcium, and whose distinct isotopic signature places a limit on the importance of this subduction flux over Earth history.

  10. Shell Bed Identification of Kaliwangu Formation and its Sedimentary Cycle Significance, Sumedang, West Java

    Directory of Open Access Journals (Sweden)

    Aswan Aswan

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i1.151Kaliwangu Formation cropping out around Sumedang area contains mollusk fossils dominated by gastropods and bivalves. In terms of sequence stratigraphy, each sedimentary cycle generally consists of four shell bed types: Early Transgressive Systems Tract (Early TST deposited above an erosional surface or sequence boundary, that is characterized by shell disarticulation, trace fossils, gravelly content, no fossil orientation direction, and concretion at the bottom; Late Transgressive Systems Tract (Late TST identified by articulated (conjoined specimen in its life position, that shows a low level abration and fragmentation, adult specimen with complete shells, and variation of taxa; Early Highstand Systems Tract (Early HST characterized by adult taxa that was found locally in their life position with individual articulation, juvenile specimens frequently occured; Late Highstand Systems Tract (Late HST determined as multiple-event concentrations, disarticulated shell domination, and some carbon or amber intercalation indicating terrestrial influence. Shell bed identification done on this rock unit identified nineteen sedimentary cycles.

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

    Science.gov (United States)

    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

  12. Geologic Mapping of Volcanic and Sedimentary Terrains, Northeast Hellas, Mars

    Science.gov (United States)

    Mest, S. C.; Crown, D. A.; Michalski, J.; Chuang, F. C.; Price Blount, K.; Bleamaster, L. F.

    2017-06-01

    We are using image, topographic, and spectral data to map the geology along the northeast rim of Hellas basin, Mars. The region displays mantled highlands, explosive and effusive volcanic materials, eroded sedimentary plains, and Dao and Niger Valles.

  13. A tectonically-induced Eocene sedimentary mélange in the West Ligurian Alps, Italy

    Science.gov (United States)

    Perotti, E.; Bertok, C.; d'Atri, A.; Martire, L.; Piana, F.; Catanzariti, R.

    2012-09-01

    The southern Alpine Foreland basin succession (Late Eocene-Early Oligocene?) lies over the Mesozoic condensed carbonate succession of the Provençal Dauphinois Domain, ends with a chaotic complex, and is overthrust by more internal Alpine units (San Remo-Monte Saccarello Ligurian unit) emplaced in Late Oligocene-Early Miocene times. The chaotic complex consists of debris flow paraconglomerates, breccias, and megablocks, up to km-sized. Despite the post-Eocene Alpine tectonics overprint, particularly intense in its uppermost part, the sedimentary origin of the chaotic complex is proved by the interbedding of paraconglomerates and breccias with fine-grained turbidites. Megablocks consist both of formations buried below the chaotic deposits (Mesozoic Provençal Dauphinois succession, Eocene Alpine Foreland basin succession) both of exotic units (Ligurian Helminthoides Flysch). Paraconglomerate and breccia clasts were sourced by the penecontemporaneous turbidite sands and muds as well as the same lithologies as megablocks. All these features suggest the activity of early Alpine Eocene strike-slip or transtensive fault systems that juxtaposed and exhumed the Helminthoides Flysch unit and the Provençal Dauphinois succession. Submarine ridges were generated and favored rock fall phenomena that involved both small, mm- to dm-sized, clasts and huge slabs detached from the main rock masses. These morphostructural highs were flanked by oversteepened slopes affected by failures that gave rise to debris flows, involving hemipelagic muds and turbidite sands and lithified fragments of older formations, which resulted in strongly polygenic paraconglomerates. The studied mélange is thus fully due to sedimentary processes that were, however, completely controlled by early Alpine tectonics.

  14. Characterization of Rock Types at Meridiani Planum, Mars using MER 13-Filter Pancam Spectra

    Science.gov (United States)

    Nuding, D. L.; Cohen, B. A.

    2009-01-01

    The Mars Exploration Rover Opportunity has traversed more than 13 km across Meridiani Planum, finding evidence of ancient aqueous environments that, in the past, may have been suitable for life. Meridiani bedrock along the rover traverse is a mixture in composition and bulk mineralogy between a sulfate-rich sedimentary rock and hematite spherules ("blueberries"). On top of the bedrock, numerous loose rocks exist. These rocks consist of both local bedrock and "cobbles" of foreign origin. The cobbles provide a window into lithologic diversity and a chance to understand other types of martian rocks and meteorites. This study was also an attempt to establish a method to expand upon those of Mini-TES to remotely identify rocks of interest to make efficient use of the rover s current resources.

  15. Alteration of Sedimentary Clasts in Martian Meteorite Northwest Africa 7034

    Science.gov (United States)

    McCubbin, F. M.; Tartese, R.; Santos, A. R.; Domokos, G.; Muttik, N.; Szabo, T.; Vazquez, J.; Boyce, J. W.; Keller, L. P.; Jerolmack, D. J.; hide

    2014-01-01

    The martian meteorite Northwest Africa (NWA) 7034 and pairings represent the first brecciated hand sample available for study from the martian surface [1]. Detailed investigations of NWA 7034 have revealed substantial lithologic diversity among the clasts [2-3], making NWA 7034 a polymict breccia. NWA 7034 consists of igneous clasts, impact-melt clasts, and "sedimentary" clasts represented by prior generations of brecciated material. In the present study we conduct a detailed textural and geochemical analysis of the sedimentary clasts.

  16. Structure and functional annotation of hypothetical proteins having putative Rubisco activase function from Vitis vinifera.

    Science.gov (United States)

    Kumar, Suresh

    2015-01-01

    Rubisco is a very large, complex and one of the most abundant proteins in the world and comprises up to 50% of all soluble protein in plants. The activity of Rubisco, the enzyme that catalyzes CO2 assimilation in photosynthesis, is regulated by Rubisco activase (Rca). In the present study, we searched for hypothetical protein of Vitis vinifera which has putative Rubisco activase function. The Arabidopsis and tobacco Rubisco activase protein sequences were used as seed sequences to search against Vitis vinifera in UniprotKB database. The selected hypothetical proteins of Vitis vinifera were subjected to sequence, structural and functional annotation. Subcellular localization predictions suggested it to be cytoplasmic protein. Homology modelling was used to define the three-dimensional (3D) structure of selected hypothetical proteins of Vitis vinifera. Template search revealed that all the hypothetical proteins share more than 80% sequence identity with structure of green-type Rubisco activase from tobacco, indicating proteins are evolutionary conserved. The homology modelling was generated using SWISS-MODEL. Several quality assessment and validation parameters computed indicated that homology models are reliable. Further, functional annotation through PFAM, CATH, SUPERFAMILY, CDART suggested that selected hypothetical proteins of Vitis vinifera contain ATPase family associated with various cellular activities (AAA) and belong to the AAA+ super family of ring-shaped P-loop containing nucleoside triphosphate hydrolases. This study will lead to research in the optimization of the functionality of Rubisco which has large implication in the improvement of plant productivity and resource use efficiency.

  17. Expression profiling of hypothetical genes in Desulfovibrio vulgaris leads to improved functional annotation

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Dwayne A.; Mukhopadhyay, Aindrila; Joachimiak, Marcin P.; Drury, Elliott C.; Redding, Alyssa M.; Yen, Huei-Che B.; Fields, Matthew W.; Hazen, Terry C.; Arkin, Adam P.; Keasling, Jay D.; Wall, Judy D.

    2008-10-27

    Hypothetical and conserved hypothetical genes account for>30percent of sequenced bacterial genomes. For the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough, 347 of the 3634 genes were annotated as conserved hypothetical (9.5percent) along with 887 hypothetical genes (24.4percent). Given the large fraction of the genome, it is plausible that some of these genes serve critical cellular roles. The study goals were to determine which genes were expressed and provide a more functionally based annotation. To accomplish this, expression profiles of 1234 hypothetical and conserved genes were used from transcriptomic datasets of 11 environmental stresses, complemented with shotgun LC-MS/MS and AMT tag proteomic data. Genes were divided into putatively polycistronic operons and those predicted to be monocistronic, then classified by basal expression levels and grouped according to changes in expression for one or multiple stresses. 1212 of these genes were transcribed with 786 producing detectable proteins. There was no evidence for expression of 17 predicted genes. Except for the latter, monocistronic gene annotation was expanded using the above criteria along with matching Clusters of Orthologous Groups. Polycistronic genes were annotated in the same manner with inferences from their proximity to more confidently annotated genes. Two targeted deletion mutants were used as test cases to determine the relevance of the inferred functional annotations.

  18. Thermal conductivity of rocks associated with energy extraction from hot dry rock geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Sibbitt, W.L.; Dodson, J.G.; Tester, J.W.

    1978-01-01

    Results of thermal conductivity measurements are given for 14 drill core rock samples taken from two exploratory HDR geothermal wellbores (maximum depth of 2929 m (9608 ft) drilled into Precambrian granitic rock in the Jemez Mountains of northern New Mexico. These samples have been petrographically characterized and in general represent fresh competent Precambrian material of deep origin. Thermal conductivities, modal analyses, and densities are given for all core samples studied under dry and water-saturated conditions. Additional measurements are reported for several sedimentary rocks encountered in the upper 760 m (2500 ft) of that same region. A cut-bar thermal conductivity comparator and a transient needle probe were used for the determinations with fused quartz and Pyroceram 9606 as the standards. The maximum temperature range of the measurements was from the ice point to 250/sup 0/C. The measurements on wet, water-saturated rock were limited to the temperature range below room temperature. Conductivity values of the dense core rock samples were generally within the range from 2 to 2.9 W/mK at 200/sup 0/C. Excellent agreement was achieved between these laboratory measurements of thermal conductivity and those obtained by in situ measurements used in the HDR wellbores. By using samples of sufficient thickness to provide a statistically representative heat flow path, no difference between conductivity values and their temperature coefficients for orthogonal directions (heat flow parallel or perpendicular to core axis) was observed. This isotropic behavior was even found for highly foliated gneissic specimens. Estimates of thermal conductivity based on a composite dispersion analysis utilizing pure minerallic phase conductivities and detailed modal analyses usually agreed to within 9 percent of the experimental values.

  19. Apollo rocks, fines and soil cores

    Science.gov (United States)

    Allton, J.; Bevill, T.

    Apollo rocks and soils not only established basic lunar properties and ground truth for global remote sensing, they also provided important lessons for planetary protection (Adv. Space Res ., 1998, v. 22, no. 3 pp. 373-382). The six Apollo missions returned 2196 samples weighing 381.7 kg, comprised of rocks, fines, soil cores and 2 gas samples. By examining which samples were allocated for scientific investigations, information was obtained on usefulness of sampling strategy, sampling devices and containers, sample types and diversity, and on size of sample needed by various disciplines. Diversity was increased by using rakes to gather small rocks on the Moon and by removing fragments >1 mm from soils by sieving in the laboratory. Breccias and soil cores are diverse internally. Per unit weight these samples were more often allocated for research. Apollo investigators became adept at wringing information from very small sample sizes. By pushing the analytical limits, the main concern was adequate size for representative sampling. Typical allocations for trace element analyses were 750 mg for rocks, 300 mg for fines and 70 mg for core subsamples. Age-dating and isotope systematics allocations were typically 1 g for rocks and fines, but only 10% of that amount for core depth subsamples. Historically, allocations for organics and microbiology were 4 g (10% for cores). Modern allocations for biomarker detection are 100mg. Other disciplines supported have been cosmogenic nuclides, rock and soil petrology, sedimentary volatiles, reflectance, magnetics, and biohazard studies . Highly applicable to future sample return missions was the Apollo experience with organic contamination, estimated to be from 1 to 5 ng/g sample for Apollo 11 (Simonheit &Flory, 1970; Apollo 11, 12 &13 Organic contamination Monitoring History, U.C. Berkeley; Burlingame et al., 1970, Apollo 11 LSC , pp. 1779-1792). Eleven sources of contaminants, of which 7 are applicable to robotic missions, were

  20. Effects of Stress on Permeation and Diffusive Properties of Rocks

    Science.gov (United States)

    Zhang, M.

    2008-12-01

    Safety assessment of facilities associated with geological disposal of various kinds of hazardous wastes, including radioactive nuclear waste, is generally performed by means of mass transport simulations combined with uncertainty and sensitivity analyses. Transport of contaminants, such as radionuclides, through an engineered and natural barrier system is principally controlled by the processes of advection, dispersion, sorption, and chain decay. Among these mechanisms, chain decay can be determined from nuclear physics, sorption can be evaluated from chemical properties of both the nuclides and rock minerals, advection and dispersion are controlled by the permeation and diffusive properties of a rock. Compared to properties related to the former two mechanisms, properties related to the latter two mechanisms are very sensitive to stress conditions. Although the effects of stress conditions on permeation or hydraulic properties of rock specimens are relatively easier to be determined and/or assessed through laboratory permeability tests, diffusion tests on rock specimens under high confining and pore pressure conditions are technically impractical, and most of laboratory diffusion tests have been performed only under atmospheric conditions. In this study, an overview of the studies related to the effects of stress on permeation properties of different types of rock is performed. Some representative experimental results illustrating the effects of stress history on permeability of sedimentary and igneous rocks obtained by the author are also presented. An approach based on empirical equations between rock permeability and porosity, effective diffusion coefficient and porosity, porosity and ground pressure, and diffusive coefficient of an interested tracer in water is proposed to predict the effective diffusion coefficient at depths, i.e., the effects of stress on diffusive properties of rocks. The applicabilities of this newly proposed approach are discussed and

  1. Chemical, multispectral, and textural constraints on the composition and origin of rocks at the Mars Pathfinder landing site

    Science.gov (United States)

    McSween, H.Y.; Murchie, S.L.; Crisp, J.A.; Bridges, N.T.; Anderson, R.C.; Bell, J.F.; Britt, D.T.; Brückner, J.; Dreibus, G.; Economou, T.; Ghosh, A.; Golombek, M.P.; Greenwood, J.P.; Johnson, J. R.; Moore, H.J.; Morris, R.V.; Parker, T.J.; Rieder, R.; Singer, R.; Wänke, H.

    1999-01-01

    Rocks at the Mars Pathfinder site are probably locally derived. Textures on rock surfaces may indicate volcanic, sedimentary, or impact-generated rocks, but aeolian abration and dust coatings prevent unambiguous interpretation. Multispectral imaging has resolved four spectral classes of rocks: gray and red, which occur on different surfaces of the same rocks; pink, which is probably soil crusts; and maroon, which occurs as large boulders, mostly in the far field. Rocks are assigned to two spectral trends based on the position of peak reflectance: the primary spectral trend contains gray, red, and pink rocks; maroon rocks constitute the secondary spectral trend. The spatial pattern of spectral variations observed is oriented along the prevailing wind direction. The primary spectral trend arises from thin ferric coatings of aeolian dust on darker rocks. The secondary spectral trend is apparently due to coating by a different mineral, probably maghemite or ferrihydrite. A chronology based on rock spectra suggests that rounded maroon boulders constitute the oldest petrologic unit (a flood deposit), succeeded by smaller cobbles possibly deposited by impact, and followed by aeolian erosion and deposition. Nearly linear chemical trends in alpha proton X-ray spectrometer rock compositions are interpreted as mixing lines between rock and adhering dust, a conclusion supported by a correlation between sulfur abundance and red/blue spectral ratio. Extrapolations of regression lines to zero sulfur give the composition of a presumed igneous rock. The chemistry and normative mineralogy of the sulfur-free rock resemble common terrestrial volcanic rocks, and its classification corresponds to andesite. Igneous rocks of this composition may occur with clastic sedimentary rocks or impact melts and breccias. However, the spectral mottling expected on conglomerates or breccias is not observed in any APXS-analyzed rocks. Interpretation of the rocks as andesites is complicated by absence

  2. Identification of the conserved hypothetical protein BPSL0317 in Burkholderia pseudomallei K96243

    Science.gov (United States)

    Yusoff, Nur Syamimi; Damiri, Nadzirah; Firdaus-Raih, Mohd

    2014-09-01

    Burkholderia pseudomallei K96243 is the causative agent of melioidosis, a disease which is endemic in Northern Australia and Southeastern Asia. The genome encodes several essential proteins including those currently annotated as hypothetical proteins. We studied the conservation and the essentiality of expressed hypothetical proteins in normal and different stress conditions. Based on the comparative genomics, we identified a hypothetical protein, BPSL0317, a potential essential gene that is being expressed in all normal and stress conditions. BPSL0317 is also phylogenetically conserved in the Burkholderiales order suggesting that this protein is crucial for survival among the order's members. BPSL0317 therefore has a potential to be a candidate antimicrobial drug target for this group of bacteria.

  3. Scattering from Rock and Rock Outcrops

    Science.gov (United States)

    2018-01-23

    quantities correspond to values of 0.86 and 18 respectively. SCATTERING FROM ROCKS 3 Figure 2. ( color online) Rough interface results from a glacially abraded...surface in (a) the low-resolution mode, and (b) the high-resolution mode. The glaciers flowed in the negative y direction. The color bar corresponds...to height reference to the surface mean, and the brightness, or black/ white information communicates the surface slope. The dashed box in (a

  4. The Influence of Hypothetical Death Scenarios on Multidimensional End-of-Life Care Preferences.

    Science.gov (United States)

    Dassel, Kara B; Utz, Rebecca; Supiano, Katherine; McGee, Nancy; Latimer, Seth

    2018-01-01

    Differences in end-of-life (EOL) care preferences (eg, location of death, use of life-sustaining treatments, openness to hastening death, etc) based on hypothetical death scenarios and associated physical and/or cognitive losses have yet to be investigated within the palliative care literature. The purpose of this study was to explore the multidimensional EOL care preferences in relation to 3 different hypothetical death scenarios: pancreatic cancer (acute death), Alzheimer disease (gradual death), and congestive heart failure (intermittent death). General linear mixed-effects regression models estimated whether multidimensional EOL preferences differed under each of the hypothetical death scenarios; all models controlled for personal experience and familiarity with the disease, presence of an advance directive, religiosity, health-related quality of life, and relevant demographic characteristics. A national sample of healthy adults aged 50 years and older (N = 517) completed electronic surveys detailing their multidimensional preferences for EOL care for each hypothetical death scenario. The average age of the participants was 60.1 years (standard deviation = 7.6), 74.7% were female, and 66.1% had a college or postgraduate degree. Results revealed significant differences in multidimensional care preferences between hypothetical death scenarios related to preferences for location of death (ie, home vs medical facility) and preferences for life-prolonging treatment options. Significant covariates of participants' multidimensional EOL care preferences included age, sex, health-related quality of life, and religiosity. Our hypothesis that multidimensional EOL care preferences would differ based on hypothetical death scenarios was partially supported and suggests the need for disease-specific EOL care discussions.

  5. Recirculation System for Geothermal Energy Recovery in Sedimentary Formations: Laboratory Experiments and Numerical Simulations

    Science.gov (United States)

    Elkhoury, J. E.; Detwiler, R. L.; Serajian, V.; Bruno, M. S.

    2012-12-01

    Geothermal energy resources are more widespread than previously thought and have the potential for providing a significant amount of sustainable clean energy worldwide. In particular, hot permeable sedimentary formations provide many advantages over traditional geothermal recovery and enhanced geothermal systems in low permeability crystalline formations. These include: (1) eliminating the need for hydraulic fracturing, (2) significant reduction in risk for induced seismicity, (3) reducing the need for surface wastewater disposal, (4) contributing to decreases in greenhouse gases, and (5) potential use for CO2 sequestration. Advances in horizontal drilling, completion, and production technology from the oil and gas industry can now be applied to unlock these geothermal resources. Here, we present experimental results from a laboratory scale circulation system and numerical simulations aimed at quantifying the heat transfer capacity of sedimentary rocks. Our experiments consist of fluid flow through a saturated and pressurized sedimentary disc of 23-cm diameter and 3.8-cm thickness heated along its circumference at a constant temperature. Injection and production ports are 7.6-cm apart in the center of the disc. We used DI de-aired water and mineral oil as working fluids and explored temperatures from 20 to 150 oC and flow rates from 2 to 30 ml/min. We performed experiments on sandstone samples (Castlegate and Kirby) with different porosity, permeability and thermal conductivity to evaluate the effect of hydraulic and thermal properties on the heat transfer capacity of sediments. The producing fluid temperature followed an exponential form with time scale transients between 15 and 45 min. Steady state outflow temperatures varied between 60% and 95% of the set boundary temperature, higher percentages were observed for lower temperatures and flow rates. We used the flow and heat transport simulator TOUGH2 to develop a numerical model of our laboratory setting. Given

  6. A Global Database for the Compilation and Assessment of Holocene Sedimentary Paleomagnetic Records

    Science.gov (United States)

    Brown, M. C.; Donadini, F.; Korte, M. C.; Frank, U.; Nilsson, A.

    2011-12-01

    Global geomagnetic field reconstructions for the Holocene can provide powerful information about the geodynamo process and can constrain geomagnetic shielding, important for our understanding of the interaction between the geomagnetic field and cosmogenic nuclide production. Coherent structure is evident in these reconstructions and this has significant implications for controls on the geodynamo. However, the resolution and reliability of current models require improvements and are limited by: 1) the restricted global coverage of sites, especially in the southern hemisphere; 2) the low precision of some magnetic data and independent dates; 3) an incomplete assessment of data quality. Improving these aspects for sedimentary records is particularly important as loosely constrained sedimentary data have a large influence on model output from spherical harmonic reconstructions of the Holocene geomagnetic field (e.g., CALS7k.2, CALS3k.3, CALS10k.1b and SED3k.1). In addition, the current SECRV00 database lacks data from the most recent studies and a number of older studies. We present our current effort to assess data quality through the design of a new database for global sedimentary data covering the last 10 ka; implemented as part of the successful GEOMAGIA50 database, already constructed for paleomagnetic data from archaeological and volcanic materials. Our aim is two-fold: 1) to transparently catalogue all available sedimentary data for the Holocene, so the broader scientific community can access a range of information related to specific cores; 2) to design a database with the functionally to select paleomagnetic data based upon parameters that reflect the fidelity of the data. To make accurate assessments of data quality it is necessary to determine paleomagnetic, rock magnetic, mineralogical and chronological parameters that may influence the fidelity of the record. We show these selected parameters and how they are implemented in the database design. All

  7. Historical and Hypothetical Future Sedimentation and Water Storage in Kajakai Reservoir, Central Afghanistan

    Science.gov (United States)

    Vining, Kevin C.; Vecchia, Aldo V.

    2008-01-01

    SUMMARY Sedimentation has reduced water storage in Kajakai Reservoir. If current sedimentation rates continue, hypothetical future reservoir water volumes at the spillway elevation of 1,033.5 meters could be reduced about 22 percent from 2006 to 2057. Even if the spillway elevation is raised to 1,045 meters, a severe drought could result in large multiyear irrigation-supply deficits in which reservoir water levels remain below 1,022 meters for more than 4 years. Hypothetical climate change and sedimentation could result in greater water-supply deficits. The chance of having sufficient water supplies in Kajakai Reservoir during the worst month is about 47 percent.

  8. Assessment of morphological architecture of feet in rock-climbers

    Directory of Open Access Journals (Sweden)

    E Demczuk-Włodarczyk

    2008-03-01

    Full Text Available It was hypothetically assumed that rock-climbers have normal foot structure. The aim of this study was to assess the structure of all the foot segments. Materials and methods: This study embraced 43 rock-climbers, who had been training for 3 to 7 years. The research group included 17 women and 26 men, aged from 18 to 24 years (mean age – 24.3. The control group consisted of 31 students of the University of Wrocław, aged from 19 to 23 years (mean age – 22.7. Photometric method was used to examine the morphological structure of the feet Results Results of the examinations show that all the rock-climbers had normal structure of the longitudinal arch, while various types of the longitudinal arch structure were observed in the students. The analysis of the transversal arch structure showed that disorders were more frequent in the rock-climbers.Conclusions. 1 Rock-climbing has a beneficial influence on the structure of the longitudinal arch, yet it is the factor facilitating disturbances of the frontal foot segments. 2 Deformations of the transversal arch structure and the toes arrangement do not coexist with the longitudinal platypodia.

  9. Rock Equity Holdings, LLC

    Science.gov (United States)

    The EPA is providing notice of an Administrative Penalty Assessment in the form of an Expedited Storm Water Settlement Agreement against Rock Equity Holdings, LLC, for alleged violations at The Cove at Kettlestone/98th Street Reconstruction located at 3015

  10. Eclogite facies rocks

    National Research Council Canada - National Science Library

    Carswell, D. A

    1990-01-01

    ... of eclogite evolution and genesis. The authors present a thorough treatment of the stability relations and geochemistry of these rocks, their intimate association with continental plate collision zones and suture zones...

  11. Pop & rock / Berk Vaher

    Index Scriptorium Estoniae

    Vaher, Berk, 1975-

    2001-01-01

    Uute heliplaatide Redman "Malpractice", Brian Eno & Peter Schwalm "Popstars", Clawfinger "A Whole Lot of Nothing", Dario G "In Full Color", MLTR e. Michael Learns To Rock "Blue Night" lühitutvustused

  12. Rock kinoekraanil / Katrin Rajasaare

    Index Scriptorium Estoniae

    Rajasaare, Katrin

    2008-01-01

    7.-11. juulini kinos Sõprus toimuval filminädalal "Rock On Screen" ekraanile jõudvatest rockmuusikuid portreteerivatest filmidest "Lou Reed's Berlin", "The Future Is Unwritten: Joe Strummer", "Control: Joy Division", "Hurriganes", "Shlaager"

  13. Aromatic compounds in crude oils and source rocks and their application to oil-source rock correlations in the Tarim basin, NW China

    Science.gov (United States)

    Jinggui, Li; Philp, Paul; Zifang, Meng; Wenhui, Liu; Jianjing, Zheng; Guojun, Chen; Mei, Li; Zhaoyun, Wang

    2005-05-01

    Ten series of aromatic hydrocarbons (biphenyls; naphthalenes; phenanthrenes; anthracenes; retenes; chrysenes; benzoanthracenes; dibenzofurans; fluorenes; and dibenzothiophenes) isolated from Cambrian and Ordovician marine carbonate source rocks in Tabei and Tazhong areas of the Tarim Basin, and Triassic and Jurassic lacustrine mudstones and swamp coals in the Kuche depression have been characterized by GC-MS. The same series of aromatic compounds have been isolated and characterized from crude oils of the Tabei and Tazhong uplift. Results presented in this paper describe the distribution of these aromatic compounds in crude oils and source rocks from the three different kinds of sedimentary environments. Similarities in distributions of the fluorenes and the dibenzothiophenes in the aromatic fractions suggest the Tabei uplift oils are derived predominantly from the Lower Ordovician marine source rocks of Tabei Lunnan area (on the south of Luntai) and the oils from Tazhong uplift are mainly derived from Upper Cambrian, Lower Ordovician, and Middle-Upper Ordovician marine source rocks of Tazhong area.

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

    NARCIS (Netherlands)

    Muhammad, Nawaz|info:eu-repo/dai/nl/357286537

    2015-01-01

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

  15. Mapping rock forming minerals at Boundary Canyon, Death Valey National Park, California, using aerial SEBASS thermal infrared hyperspectral image data

    Science.gov (United States)

    Aslett, Zan; Taranik, James V.; Riley, Dean N.

    2018-02-01

    Aerial spatially enhanced broadband array spectrograph system (SEBASS) long-wave infrared (LWIR) hyperspectral image data were used to map the distribution of rock-forming minerals indicative of sedimentary and meta-sedimentary lithologies around Boundary Canyon, Death Valley, California, USA. Collection of data over the Boundary Canyon detachment fault (BCDF) facilitated measurement of numerous lithologies representing a contact between the relatively unmetamorphosed Grapevine Mountains allochthon and the metamorphosed core complex of the Funeral Mountains autochthon. These included quartz-rich sandstone, quartzite, conglomerate, and alluvium; muscovite-rich schist, siltstone, and slate; and carbonate-rich dolomite, limestone, and marble, ranging in age from late Precambrian to Quaternary. Hyperspectral data were reduced in dimensionality and processed to statistically identify and map unique emissivity spectra endmembers. Some minerals (e.g., quartz and muscovite) dominate multiple lithologies, resulting in a limited ability to differentiate them. Abrupt variations in image data emissivity amongst pelitic schists corresponded to amphibolite; these rocks represent gradation from greenschist- to amphibolite-metamorphic facies lithologies. Although the full potential of LWIR hyperspectral image data may not be fully utilized within this study area due to lack of measurable spectral distinction between rocks of similar bulk mineralogy, the high spectral resolution of the image data was useful in characterizing silicate- and carbonate-based sedimentary and meta-sedimentary rocks in proximity to fault contacts, as well as for interpreting some mineral mixtures.

  16. Stick-Slip of Lightly Loaded Rock. Part 1. Dilatancy and Shearing Behavior of Assemblages of Rods. Part 2

    Science.gov (United States)

    1975-02-04

    behavior of paired roughly ground surfaces of limestone, basalt, and quartzite. An alternating ,: bort -and-long slip with intermediate creep oc...34Sliding Friction Tests on Sedimentary Rock Specimens," Communication 8, Seventh Congress on Large Dams , Vol. 4, 1961, pp. 657-671. 65 Simkins, T. E., "The

  17. Rock erodibility and the interpretation of low-temperature thermochronologic data

    Science.gov (United States)

    Flowers, Rebecca M.; Ehlers, Todd A.

    2018-01-01

    Rocks vary significantly in strength and erodibility. Here we evaluate if rock erodibility variations should be considered when interpreting thermochronologic datasets. We do this by applying 1D thermo-kinematic numerical models that exhume two lithologies of contrasting erodibility. For thick layers (>2 km), soft over hard layering causes earlier cooling and therefore older thermochronologic dates than no layering, with the opposite true for hard over soft layering. In some circumstances, even 2-10x erodibility contrasts substantially influence the results, and a 10x erodibility contrast can be nearly as important as contrasts several orders of magnitude greater. Thinner alternating layers (rock erodibility variations should not substantially influence thermochronologic data from most continental sedimentary packages, which are dominated by lithologic layering rocks. For example, the abrupt cooling and erosion rate decrease recorded by thermochronologic data from Rocky Mountain basement uplifts of the western U.S. coincides with when erosion-resistant Precambrian basement was exposed after removal of softer sedimentary cover. These data may largely record a change in exposed rock type erodibility rather than a dramatic change in external erosional forcing. Our results suggest that in some cases, variations in rock erodibility should be considered when interpreting cooling and erosion histories from thermochronologic datasets.

  18. Mesozoic and Cenozoic rocks from Malta Escarpment (central Mediterranean)

    Energy Technology Data Exchange (ETDEWEB)

    Scandone, P. (Istituto di Geologia e Paleontologia, Pisa, Italy); Patacca, E.; Radoicic, R.; Ryan, W.B.F.; Cita, M.B.; Rawson, M.; Chezar, H.; Miller, E.; McKenzie, J.; Rossi, S.

    1981-07-01

    Sedimentary rocks of Triassic-Neogene age are present on the Malta Escarpment of the eastern Mediterranean. Upper Triassic dolomitic limestones of shallow-water origin, at depths between 2.5 and 3.5 km, are similar in lithofacies to coeval platform carbonates of the Siracusa (Syracuse) belt of southern Sicily. Jurassic rocks include lower-middle Liassic shallow-water limestones followed by condensed hemipelagic lime deposits indicative of sinking and starving of the former platform. Cretaceous materials are represented by both red marls rich in planktonic faunas and reworkd volcaniclastic breccias including shallow-water skeletal material. Paleogene rocks are both shallow-water limestones with corals, algae, and bivalves, and redeposited calcarenites of lithofacies similar to those from surface and subsurface of the Ragusa zone. Oligocene-lower Miocene rocks from the escarpment are also similar in lithology to the coeval Ragusa deposits. Tortonian is represented by hemipelagic marls indicating open-marine environment. Pervasive dolomitization on lime crusts and on initial-stage fissure fillings with strongly positive isotopic oxygen ratio is thought to be a product of Messinian evaporitic drawdown. Pliocene sediments belong to the Trubi facies and consist of pelagic foraminiferal chalk. An impressive vertical relief existed by Miocene times, as attested by Messinian crusts and veins on or in rocks as old as Late Triassic. Our data do not provide evidence that this morphologic feature necessarily coincides with a continent-ocean transition. The present escarpment was produced by faulting, erosion, and defacement. 14 figures, 1 table.

  19. Using Modeling Clay to Model the Rock Cycle

    Science.gov (United States)

    Cook, H. M.

    2016-12-01

    During this interactive exploration, students will be guided through the rock cycle using modeling clay as a medium. Each student will be given a ball of red clay and a ball of yellow clay. The instructor will introduce students to igneous rocks as they use their red clay to create a volcano. Students will then learn about weathering and erosion as they break their yellow ball of clay into smaller and smaller pieces that they will round into spheres. The "sand" created from the yellow clay gets accumulated and lithified (via gentle compression by the students) to form a sandstone. This sandstone then becomes covered by a lava flow, created by smashing the red clay volcanoes. The process of metamorphism is introduced as students gently cover their sandstone using the lava flow. This also serves a segue for a discussion about the various types of metamorphism beginning with contact metamorphism. Metamorphic grade is discussed as increased pressure further alters the sedimentary rock and lava flow. Ultimately a migmatite is formed by mixing the red and yellow clay together. Finally, they clays become so intermingled that a new larger orange ball is created, beginning the rock cycle anew with an igneous melt. This activity is engaging and effective with students of all ages. Intended as a fun, light-hearted approach to introducing rocks in an undergraduate earth science class, this can be effectively customized for use in an elementary, middle, or high school classroom.

  20. Rock and Soil Rheology

    Science.gov (United States)

    Cristescu, Nicolae; Ene, Horia I.

    The first part of the volume contains theoretical considerations of the physical properties of soils and rocks. Articles on the mechanical and kinematical behavior of rocks as well as mathematical models are the base for the understanding of the physical properties of natural systems. In the second part articles deal with experiments and applications regarding creep deformation of clay, underground cavities, tunnels and deformation of sand and lamistrine sediments.

  1. Electrical resistivity dynamics beneath a fractured sedimentary bedrock riverbed in response to temperature and groundwater–surface water exchange

    Directory of Open Access Journals (Sweden)

    C. M. Steelman

    2017-06-01

    Full Text Available Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwater–surface water exchange. In this study, surface electrical methods were used as a non-invasive technique to assess the scale and temporal variability of riverbed temperature and groundwater–surface water interaction beneath a sedimentary bedrock riverbed. Conditions were monitored at a semi-daily to semi-weekly interval over a full annual period that included a seasonal freeze–thaw cycle. Surface electromagnetic induction (EMI and electrical resistivity tomography (ERT methods captured conditions beneath the riverbed along a pool–riffle sequence of the Eramosa River in Canada. Geophysical datasets were accompanied by continuous measurements of aqueous specific conductance, temperature, and river stage. Time-lapse vertical temperature trolling within a lined borehole adjacent to the river revealed active groundwater flow zones along fracture networks within the upper 10 m of rock. EMI measurements collected during cooler high-flow and warmer low-flow periods identified a spatiotemporal riverbed response that was largely dependent upon riverbed morphology and seasonal groundwater temperature. Time-lapse ERT profiles across the pool and riffle sequence identified seasonal transients within the upper 2 and 3 m of rock, respectively, with spatial variations controlled by riverbed morphology (pool versus riffle and dominant surficial rock properties (competent versus weathered rock rubble surface. While the pool and riffle both exhibited a dynamic resistivity through seasonal cooling and warming cycles, conditions beneath the pool were more variable, largely due to the formation of river

  2. Influence of sedimentary layering on tsunami generation

    CERN Document Server

    Dutykh, Denys

    2008-01-01

    The present article is devoted to the influence of sediment layers on the process of tsunami generation. The main scope here is to demonstrate and especially quantify the effect of sedimentation on seabed vertical displacements due to an underwater earthquake. The fault is modelled as a Volterra-type dislocation in an elastic half-space. The elastodynamics equations are integrated with a finite element method. A comparison between two cases is performed. The first one corresponds to the classical situation of an elastic homogeneous and isotropic half-space, which is traditionally used for the generation of tsunamis. The second test case takes into account the presence of a sediment layer separating the oceanic column from the hard rock. Some important differences are revealed. The results of the present study may partially explain why the great Sumatra-Andaman earthquake of 26 December 2004 produced such a big tsunami. More precisely, we conjecture that the wave amplitude in the generation region may have bee...

  3. Remoção de Pb2+ e Cr3+ em solução por zeólitas naturais associadas a rochas eruptivas da formação serra geral, bacia sedimentar do Paraná Removal of Pb2+ and Cr3+ from aqueous solution by natural zeolites associated with eruptive rocks from the serra geral formation, Paraná sedimentary basin

    Directory of Open Access Journals (Sweden)

    Mirian Chieko Shinzato

    2009-01-01

    Full Text Available The capacity of natural zeolites and its host rock (dacite to remove Pb2+ and Cr3+ from aqueous solutions has been investigated. Results showed that both samples prefer to remove Pb2+ instead of Cr3+. Almost 100% of Pb2+ was removed from solutions with concentration until 50 mg L-1 and 100 mg L-1 of this metal, respectively by dacite and zeolite. The equilibrium of metals adsorption process was reached during the first 30 min by both materials. Na+ can be used to recover Pb2+, but not to remove Cr3+ from the treated samples. The Sips model showed a good fit for experimental data of this study.

  4. Structural Analysis of Hypothetical Proteins from Helicobacter pylori: An Approach to Estimate Functions of Unknown or Hypothetical Proteins

    Directory of Open Access Journals (Sweden)

    Bong-Jin Lee

    2012-06-01

    Full Text Available Helicobacter pylori (H. pylori have a unique ability to survive in extreme acidic environments and to colonize the gastric mucosa. It can cause diverse gastric diseases such as peptic ulcers, chronic gastritis, mucosa-associated lymphoid tissue (MALT lymphoma, gastric cancer, etc. Based on genomic research of H. pylori, over 1600 genes have been functionally identified so far. However, H. pylori possess some genes that are uncharacterized since: (i the gene sequences are quite new; (ii the function of genes have not been characterized in any other bacterial systems; and (iii sometimes, the protein that is classified into a known protein based on the sequence homology shows some functional ambiguity, which raises questions about the function of the protein produced in H. pylori. Thus, there are still a lot of genes to be biologically or biochemically characterized to understand the whole picture of gene functions in the bacteria. In this regard, knowledge on the 3D structure of a protein, especially unknown or hypothetical protein, is frequently useful to elucidate the structure-function relationship of the uncharacterized gene product. That is, a structural comparison with known proteins provides valuable information to help predict the cellular functions of hypothetical proteins. Here, we show the 3D structures of some hypothetical proteins determined by NMR spectroscopy and X-ray crystallography as a part of the structural genomics of H. pylori. In addition, we show some successful approaches of elucidating the function of unknown proteins based on their structural information.

  5. Sedimentary records on the subduction-accretion history of the Russian Altai, northwestern Central Asian Orogenic Belt

    Science.gov (United States)

    Chen, Ming; Sun, Min

    2017-04-01

    The Russian Altai, comprising the northern segment of the Altai-Mongolian terrane (AM) in the south, the Gorny Altai terrane (GA) in the north and the intervening Charysh-Terekta-Ulagan-Sayan suture zone, is a key area of the northwestern Central Asian Orogenic Belt (CAOB). A combined geochemical and detrital zircon study was conducted on the (meta-)sedimentary sequences from the Russian Altai to reveal the tectono-magmatic history of these two terranes and their amalgamation history, which in turn place constraints on the accretionary orogenesis and crustal growth in the CAOB. The Cambrian-Ordovician meta-sedimentary rocks from the northern AM are dominated by immature sediments possibly sourced from intermediate-felsic igneous rocks. Geochemical data show that the sediments were likely deposited in a continental arc-related setting. Zircons separated from these rocks are mainly 566-475 Ma and 1015-600 Ma old, comparable to the magmatic records of the Tuva-Mongolian terrane and surrounding island arcs in the western Mongolia. The similar source nature, provenance and depositional setting of these rocks to the counterparts from the Chinese Altai (i.e., the southern AM) imply that the whole AM possibly represents a coherent accretionary prism of the western Mongolia in the early Paleozoic rather than a Precambrian continental block with passive marginal deposition as previously thought. In contrast, the Cambrian to Silurian (meta-)sedimentary rocks from the GA are characterized by a unitary zircon population with ages of 640-470 Ma, which were potentially sourced from the Kuznetsk-Altai intra-oceanic island arc in the east of this terrane. The low abundance of 640-540 Ma zircons (5%) may attest that this arc was under a primitive stage in the late Neoproterozoic, when mafic igneous rocks dominated. However, the voluminous 530-470 Ma zircons (95%) suggest that this arc possibly evolved toward a mature one in the Cambrian to early Ordovician with increasing amount of

  6. Impacts of fluvial sedimentary heterogeneities on CO2 storage performance

    Science.gov (United States)

    Issautier, B. H.; Viseur, S.; Audigane, P. D.

    2011-12-01

    The heterogeneity of fluvial systems is a key parameter in sedimentology due to the associated impacts on flow performance. In a broader context, fluvial reservoirs are now targets for CO2 storage projects in several sedimentary basins (Paris Basin, North German Basin), thus calling for detailed characterization of reservoir behaviour and capacity. Fluvial reservoirs are a complex layout of highly heterogeneous sedimentary bodies with varying connectivity, depending on the sedimentary history of the system. Reservoir characterization must determine (a) the nature and dimension of the sedimentary bodies, and (b) the connectivity drivers and their evolution throughout the stratigraphic succession. Based on reservoir characterization, geological modelling must account for this information and can be used as a predictive tool for capacity estimation. Flow simulation, however, describes the reservoir behaviour with respect to CO2 injection. The present work focuses on fluvial reservoir performance and was carried out as part of a PhD (2008-2011) dedicated to the impact of sedimentary heterogeneity on CO2 storage performance. The work comprises three steps: ? Reservoir characterization based on detailed fieldwork (sedimentology and sequence stratigraphy) carried out in Central Arabia on the Minjur Sandstone. Twelve depositional environments and their associated heterogeneity are identified, and their layout is presented in a high-resolution sequence stratigraphy analysis. This step is summed up in a 3D geological model. ? Conceptual modelling based on this field data, using gOcad software and an in-house python code. The purpose was to study, for a given architecture, the impact of sedimentary heterogeneity on storage capacity estimations using two models: one with heterogeneity within the sedimentary fill (model A); the other without heterogeneity within the sedimentary fill (model B). A workflow was designed to estimate and compare the storage capacities for a series

  7. Sc, Y, La-Lu. Rare earth elements. Vol. A 6a. Y, La, and the lanthanoids. Geochemistry: Sedimentary cycle. Metamorphic cycle. 8. rev. ed

    Energy Technology Data Exchange (ETDEWEB)

    Ditz, R.; Sarbas, B.; Schubert, P.; Toepper, W.

    1988-01-01

    The present volume 'Rare Earth Elements' A 6a describes origin, mode of occurrence, and behavior of Y and RE elements in the sedimentary and metamorphic cycles, and completes the series of volumes describing cosmo- and geochemistry of these elements. In the chapter 'Sedimentary Cycle', the behavior of Y and RE during the weathering process is first outlined under both marine and terrestrial conditions, including a short compilation for migration and precipitation in surficial weathering and oxidation zones. The main part of the chapter treats, in addition to the mode of occurrence, predominantly the distribution of Y and RE in the different types of sedimentary rocks in relation to genetic processes (comprising physical and/or spatial factors such as geological age of the deposition). A concluding part gives a description of mobilization, migration, and precipitation of Y and RE during the diagenetic transformation of sediments, especially in relation to the various types of ferromanganese concretions. In the chapter 'Metamorphic Cycle', the first, extensive part gives examples of mode of occurrence and behavior of Y and RE during both the contact-metamorphic and prograde and retrograde regional-metamorphic processes affecting sedimentary and igeneous source rocks. The second part briefly describes behaviour of Y and RE during ultrametamorphism of metamorphic rocks, and during metamorphic processes in connection with special types of geologic events (as, e.g., subduction of crustal material into the earth's mantle and impact of extraterrestrial material). (orig.) With 4 figs.

  8. Guided Geothermal Exploration in Hot Sedimentary Aquifers

    Science.gov (United States)

    Wellmann, J.; Horowitz, F. G.; Ricard, L.; Regenauer-Lieb, K.

    2010-12-01

    The search for a suitable reservoir site in a geothermal system depends on many factors. In Hot Sedimenatry Aquifer systems (i.e. deep, permeable geological units filled with hot fluids and with a significant regional extent), mostly important are hydraulic conductivity, fluid temperature and heat capacity. These factors are strongly coupled. For example, hydraulic conductivity depends on fluid viscosity which itself is a function of temperature. We can therefore derive the most meaningful estimation of parameters at depth when we consider all these coupling effects - instead of simply interpolating measured values. The best way to incorporate the relevant factors and their couplings is to create a mathematical model of the subsurface, considering all important physical effects (usually done in thermo-hydraulic simulations). Results of these simulations are the distribution of thermodynamic properties (temperature, pressure) and rock properties (permeability, porosity, thermal conductivity, etc.) in space. Only certain combinations of these properties will finally lead to a suitable location for a geothermal reservoir. Also, other relevant aspects have to be considered, like the regional extent of the aquifer, its thickness and natural groundwater flow. We developed methods to combine many of these relevant factors into coherent models, the results of which can be visualized in simple exploration maps. We are considering two highly important factors: (a) the available heat density, related to a minimum temperature (``Lindal-Maps'') and (b) the sustainability of the system, considering a potential pumping and reinjection well doublet scheme. Example applications show how our estimations can help locate a potential geothermal reservoir. Estimation of a maximal pumping rate for the theoretical case of no thermal breakthrough, in the presence of advection. This is of practical significance as areas with a high value can also be expected to allow a higher sustainable

  9. Valuing hypothetical wildfire impacts with a Kuhn–Tucker model of recreation demand

    Science.gov (United States)

    Jose Sanchez; Ken Baerenklau; Armando Gonzalez-Caban

    2016-01-01

    This study uses a nonmarket valuation method to investigate the recreation values of the San Jacinto Wilderness in southern California. The analysis utilizes survey data from a stated-choice experiment involving backcountry visitors who responded to questions about hypothetical wildfire burn scenarios. Benefits of landscape preservation are derived using a Kuhn-Tucker...

  10. Conflict Resolution among Preschool Children: The Appeal of Negotiation in Hypothetical Disputes.

    Science.gov (United States)

    Iskandar, Niveen; And Others

    1995-01-01

    Using hypothetical puppet interviews, 48 preschool children were interviewed about their preferences for teacher methods of conflict intervention. Puppet vignettes contrasted conflict issue, peer status, and resolution strategy (negotiation, power assertion, and disengagement). Results showed that preschoolers preferred negotiation strategies over…

  11. The Effects of Real Versus Hypothetical Stimuli upon Preschool Children's Helping Behavior.

    Science.gov (United States)

    Sharpley, Christopher F.; Rodd, Jillian

    1985-01-01

    Examined effects of presentation of a peer-in-need stimulus to preschool children in real versus hypothetical contexts, with results indicating a significantly higher incidence of helping behavior in real situations. Nature of helping response as a preoperational reaction to concrete contextual cues is verified. (Author/DST)

  12. Adolescents' explicit and implicit evaluations of hypothetical and actual peers with different bullying participant roles

    NARCIS (Netherlands)

    Pouwels, J.L.; Lansu, T.A.M.; Cillessen, A.H.N.

    2017-01-01

    This study examined how adolescents evaluate bullying at three levels of specificity: (a) the general concept of bullying, (b) hypothetical peers in different bullying participant roles, and (c) actual peers in different bullying participant roles. Participants were 163 predominantly ethnic majority

  13. In silico Structural and Functional Annotation of Mycoplasma genitalium Hypothetical Protein MG_377

    Directory of Open Access Journals (Sweden)

    Sudip Paul

    2015-04-01

    Full Text Available Mycoplasma genitalium, a Gram-positive sexually transmitted pathogen, has been associated with urethritis in men and several inflammatory reproductive tract syndromes in women including cervicitis, pelvic inflammatory disease, and infertility. The complete sequence of the M. genitalium G37 genome revealed that it consists of 94 hypothetical proteins with unknown function in addition to functional proteins. In the present study, the MG_377 hypothetical protein of M. genitalium was selected for analyzing and modeling by different bioinformatics tools and databases. According to primary and secondary structure analyses, MG_377 is a stable hydrophilic protein containing a significant proportion of α-helices; besides, it is a cytoplasmic protein based on subcellular localization predictions. Homology modeling method was applied to generate its 3D structure using SWISS-MODEL server where the template PDB 1ZXJ with 84.4% sequence identity with the hypothetical protein was exploited. Several evaluations of quality assessment and validation parameters specified the generated protein model as reliable with fairly good quality. Functional genomics analysis carried out by InterProScan, Pfam and NCBI-CDD suggested that the hypothetical protein may contain Trigger factor/SurA domain. Moreover, comparative genomics analysis recommended MG_377 as a non-homologous protein essential for the organism. Further experimental validation would help to identify the actual function of MG_377 as well as to confirm the utility of the protein as drug targets.

  14. study and analysis of asa river hypothetical dam break using hec-ras

    African Journals Online (AJOL)

    A hypothetical dam break on Asa Dam located in Ilorin, Kwara State, Nigeria was analyzed using United States Army Corps of Engineers (USACE), Hydrologic Engineering Center's River Analysis System (HEC-RAS) computer model. Unsteady flow simulation was performed using geometric data obtained from Digital ...

  15. Bioinformatics and structural characterization of a hypothetical protein from Streptococcus mutans

    DEFF Research Database (Denmark)

    Nan, Jie; Brostromer, Erik; Liu, Xiang-Yu

    2009-01-01

    . From the interlinking structural and bioinformatics studies, we have concluded that SMU.440 could be involved in polyketide-like antibiotic resistance, providing a better understanding of this hypothetical protein. Besides, the combination of multiple methods in this study can be used as a general...

  16. fMRI evidence of a hot-cold empathy gapin hypothetical and real aversive choices

    Directory of Open Access Journals (Sweden)

    Min Jeong Kang

    2013-06-01

    Full Text Available Hypothetical bias is the common finding that hypothetical monetary values for goods are higher than real values. We extend this research to the domain of bads such as consumer and household choices made to avoid aversive outcomes (e.g., insurance. Previous evidence of hot-cold empathy gaps suggest food disgust is likely to be strongly underestimated in hypothetical (cold choice. Depending on relative underestimation of food disgust and pain of spending, the hypothetical bias for aversive bads can go in the typical direction for goods, disappear, or reverse in sign. We find that the bias is reversed in sign—subjects pay more to avoid bads when choice is real. fMRI shows that real choice more strongly activates striatum and medial prefrontal cortex (reward regions and shows distinct activity in insula and amygdala (disgust and fear regions. The neural findings suggest ways to exogeneously manipulate or record brain activity in order to create better forecasts of actual consumer choice.

  17. Physicians' willingness to grant requests for assistance in dying for children: a study of hypothetical cases

    NARCIS (Netherlands)

    Vrakking, A.M.; van der Heide, A.; Looman, C.W.; van Delden, J.J.M.; Philipsen, B.D.; van der Maas, P.J.; van der Wal, G.

    2005-01-01

    OBJECTIVE: To study the willingness of Dutch physicians to use potentially life-shortening or lethal drugs for severely ill children. STUDY DESIGN: We asked 63 pediatricians about their approach to 10 hypothetical cases of children with cancer. The age of the child (15, 11, or 6 years), the child's

  18. Adolescents' Reactions to Hypothetical Peer Group Conversations: Evidence for an Imaginary Audience?

    Science.gov (United States)

    Vartanian, Lesa Rae

    2001-01-01

    The nature of early adolescent social cognition as characterized by the theory of adolescent egocentrism was investigated, through three studies, by examining age differences in judgments of hypothetical peer conversations. Findings do not support the notion that adolescents believe others are attentive to and critical of their every move, or that…

  19. The impact of arbitrarily applicable relational responding on evaluative learning about hypothetical money and shock outcomes.

    Science.gov (United States)

    Dymond, Simon; Molet, Mikael; Davies, Lynette

    2017-08-01

    Evaluative learning comprises changes in preferences after co-occurrences between conditioned stimuli (CSs) and an unconditioned stimulus (US) of affective value. Co-occurrences may involve relational responding. Two experiments examined the impact of arbitrary relational responding on evaluative preferences for hypothetical money and shock outcomes. In Experiment 1, participants were trained to make arbitrary relational responses by placing CSs of the same size but different colours into boxes and were then instructed that these CSs represented different intensities of hypothetical USs (money or shock). Liking ratings of the CSs were altered in accordance with the underlying bigger/smaller than relations. A reversal of preference was also observed: the CS associated with the smallest hypothetical shock was rated more positively than the CS associated with the smallest amount of hypothetical money. In Experiment 2, procedures from Relational Frame Theory (RFT) established a relational network of more than/less than relations consisting of five CSs (A-B-C-D-E). Overall, evaluative preferences were altered, but not reversed, depending on (a) how stimuli had been related to one another during the learning phase and (b) whether those stimuli referred to money or shocks. The contribution of RFT to evaluative learning research is discussed.

  20. Consequences in Norway after a hypothetical accident at Sellafield - Predicted impacts on the environment.

    Energy Technology Data Exchange (ETDEWEB)

    Thoerring, H.; Liland, A.

    2010-12-15

    This report deals with the environmental consequences in Norway after a hypothetical accident at Sellafield. The investigation is limited to the terrestrial environment, and focus on animals grazing natural pastures, plus wild berries and fungi. Only 137Cs is considered. The predicted consequences are severe, in particular for mutton and goat milk production. (Author)

  1. Cataloging Common Sedimentary and Deformation Features in Valles Marineris

    Science.gov (United States)

    Urso, A.; Okubo, C. H.

    2015-12-01

    The sedimentary deposits in the Valles Marineris region of Mars are investigated to build a catalog of sedimentary and deformational features. The occurrence of these features provides new and important constraints on the origins of these sedimentary deposits and of their broader geologic histories. Regional surveys and mapping of these features is warranted given the plethora of recently acquired observations by the Mars Reconnaissance Orbiter. Select sedimentary and deformational features were identified using High Resolution Imaging Science Experiment (HiRISE) observations and stereo pairs, along with Context camera images. Feature locations were cataloged using Java Mission-planning and Analysis for Remote Sensing (JMARS) the geospatial information system. Images acquired in and around Hebes, Ophir, Tithonium, Candor, Ius, Melas and Coprates Chasmata were the focus of this investigation. Mass wasting processes, soft-sediment deformation structures, and fan-like deposits are known to occur in abundance across the Valles Marineris region. For this reason, the features recorded in this investigation were landslides, contorted bedding, injectites, putative mud volcanoes, faults, folds, and fan-shaped deposits. Landslides, faults, and fan-shaped deposits were found to be common occurrences, while contorted bedding, injectites, putative mud volcanoes, and folds occur less frequently and in clusters. The placement and frequency of these features hint at past tectonic and depositional processes at work in Valles Marineris. This catalogue of sedimentary and deformational features in the Valles Marineris region of Mars is being used to define targets for future HiRISE observations.

  2. QEMSCAN+LAICPMS: a new tool for petrochronology and sedimentary provenance analysis

    Science.gov (United States)

    Vermeesch, Pieter; Rittner, Martin; Omma, Jenny

    2017-04-01

    Only a relatively small number of rock-forming minerals contain sufficiently high concentrations of naturally occurring radioactive parent isotopes and sufficiently low background concentrations of the corresponding daughter isotopes to be suitable for geochronology. The first step in most geochronological studies is to extract these datable minerals from the host rock using a combination of magnetic and density separation techniques, a process that is tedious and time consuming. We here present a new method to avoid mineral separation by coupling a QEMSCAN electron microscope to an LA-ICP-MS instrument. Given a polished hand specimen, a petrographic thin section, or a grain mount, the QEMSCAN+LAICPMS method produces chemical and mineralogical maps from which the X-Y coordinates of the datable mineral are extracted. These coordinates are subsequently passed on to the laser ablation system for isotopic and, hence, geochronological analysis. QEMSCAN+LAICPMS can be applied to a wide range of problems in igneous, metamorphic and sedimentary geology, as is illustrated with three case studies. In the first case study, a 3 × 4 cm slab of polished granite from the L'Erée pluton in Guernsey is scanned for zircon. This yields 23 U-Pb ages resulting in a concordia age of 615 ± 2 Ma. The second case study re-investigates a paragneiss from an ultra-high pressure terrane in the Qaidam Basin (Qinghai, China) that was previously analysed by conventional petrography, electron microscopy and SIMS zircon U-Pb analysis. In this example, the QEMSCAN revealed 107 small (20 μm) metamorphic zircons that were analysed by LA-ICP-MS to constrain the 430 Ma age of peak metamorphism. The third and final case study investigates the mineralogy and geochronology of sedimentary rocks of the Ordovician Sarah Formation (Saudi Arabia). We analysed 44 outcrop samples and a further 35 subsurface samples, resulting in a dataset comprising 10,000 detrital zircon U-Pb ages and 79 heavy mineral

  3. Characterizing flow pathways in a sandstone aquifer: Tectonic vs sedimentary heterogeneities

    Science.gov (United States)

    Medici, G.; West, L. J.; Mountney, N. P.

    2016-11-01

    Sandstone aquifers are commonly assumed to represent porous media characterized by a permeable matrix. However, such aquifers may be heavy fractured when rock properties and timing of deformation favour brittle failure and crack opening. In many aquifer types, fractures associated with faults, bedding planes and stratabound joints represent preferential pathways for fluids and contaminants. In this paper, well test and outcrop-scale studies reveal how strongly lithified siliciclastic rocks may be entirely dominated by fracture flow at shallow depths (≤ 180 m), similar to limestone and crystalline aquifers. However, sedimentary heterogeneities can primarily control fluid flow where fracture apertures are reduced by overburden pressures or mineral infills at greater depths. The Triassic St Bees Sandstone Formation (UK) of the East Irish Sea Basin represents an optimum example for study of the influence of both sedimentary and tectonic aquifer heterogeneities in a strongly lithified sandstone aquifer-type. This fluvial sedimentary succession accumulated in rapidly subsiding basins, which typically favours preservation of complete depositional cycles including fine grained layers (mudstone and silty sandstone) interbedded in sandstone fluvial channels. Additionally, vertical joints in the St Bees Sandstone Formation form a pervasive stratabound system whereby joints terminate at bedding discontinuities. Additionally, normal faults are present through the succession showing particular development of open-fractures. Here, the shallow aquifer (depth ≤ 180 m) was characterized using hydro-geophysics. Fluid temperature, conductivity and flow-velocity logs record inflows and outflows from normal faults, as well as from pervasive bed-parallel fractures. Quantitative flow logging analyses in boreholes that cut fault planes indicate that zones of fault-related open fractures characterize 50% of water flow. The remaining flow component is dominated by bed-parallel fractures

  4. An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, M.; Hiratsuka, T.; Ito, K.; Finsterle, S.

    2011-02-01

    Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an

  5. Sedimentary features of the Blackhawk formation (Cretaceous) at Sunnyside, Carbon County, Utah

    Science.gov (United States)

    Maberry, John O.

    1968-01-01

    The Blackhawk Formation at Sunnyside, Utah, was deposited along the western margin of the Western Interior Cretaceous sea during southeastward withdrawal of the sea. Sand was the dominant type of land-derived sediment deposited in the Sunnyside district during the regressive phases. Sand bodies prograded seaward in response to changing sediment supply from a source west of Sunnyside. Where conditions were favorable for the accumulation of vegetable material, peat deposits formed and were later changed to bituminous Coal by diagenesis. Studies of the coal bed show that the coals were formed from accumulation of small, low-growing plants and plant debris that was transported into the area of accumulation. Remains of large plants in the coals are rare. Trace fossils, which are tracks, trails and burrows formed by organisms and preserved in the rock, are extremely abundant in the Blackhawk rocks. These biogenic sedimentary structures are common in Cretaceous deposits throughout the western United States. Trace fossil distribution in the rocks is controlled by the depositional environment preferred by their creators. A study of the trace fossils of a. locality allows a more precise determination of the conditions during deposition of the sediments. Water depth, bottom conditions, salinity, current velocity and amount of suspended nutrients in the water are some of the environmental factors that may be reconstructed by studying trace fossils. The Blackhawk Formation at Sunnyside comprises the members, the Kenilworth Member and the Sunnyside Member. Field studies show that the formation may be further subdivided in the Sunnyside district., according to the precepts of units of mappable thickness and similar lithologic characteristics. The Blackhawk pinches out eastward and north. ward into the Mancos Shale, and names for submembers become meaningless. Names are of value in the region of interest, however, because of the prominence of the named units. Coal mining is the

  6. Session: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  7. Fault Rock Variation as a Function of Host Rock Lithology

    Science.gov (United States)

    Fagereng, A.; Diener, J.

    2013-12-01

    Fault rocks contain an integrated record of the slip history of a fault, and thereby reflect the deformation processes associated with fault slip. Within the Aus Granulite Terrane, Namibia, a number of Jurassic to Cretaceous age strike-slip faults cross-cut Precambrian high grade metamorphic rocks. These strike-slip faults were active at subgreenschist conditions and occur in a variety of host rock lithologies. Where the host rock contains significant amounts of hydrous minerals, representing granulites that have undergone retrogressive metamorphism, the fault rock is dominated by hydrothermal breccias. In anhydrous, foliated rocks interlayered with minor layers containing hydrous phyllosilicates, the fault rock is a cataclasite partially cemented by jasper and quartz. Where the host rock is an isotropic granitic rock the fault rock is predominantly a fine grained black fault rock. Cataclasites and breccias show evidence for multiple deformation events, whereas the fine grained black fault rocks appear to only record a single slip increment. The strike-slip faults observed all formed in the same general orientation and at a similar time, and it is unlikely that regional stress, strain rate, pressure and temperature varied between the different faults. We therefore conclude that the type of fault rock here depended on the host rock lithology, and that lithology alone accounts for why some faults developed a hydrothermal breccia, some cataclasite, and some a fine grained black fault rock. Consequently, based on the assumption that fault rocks reflect specific slip styles, lithology was also the main control on different fault slip styles in this area at the time of strike-slip fault activity. Whereas fine grained black fault rock is inferred to represent high stress events, hydrothermal breccia is rather related to events involving fluid pressure in excess of the least stress. Jasper-bearing cataclasites may represent faults that experienced dynamic weakening as seen

  8. Use of mineralogical analysis in geotechnical assessment of rock strata for coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Colin R.; Nunt-jaruwong, Sorawit; Swanson, Jeni [School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052 (Australia)

    2005-10-17

    The fundamental geotechnical properties of sedimentary rocks from the coal-bearing Sydney Basin of New South Wales, Australia, including density, porosity, water absorption and moisture content, as well as compressive strength, have been related to the mineralogy of the materials as determined by quantitative X-ray diffraction of powdered rock samples and processing by the Rietveld-based Siroquant technique. The results show, for example, that the overall proportions of clay minerals in the rocks, as well as the types of clay minerals present, affect properties such as water absorption and moisture content. The presence of clay minerals also adds to the dry strength of silica-cemented quartz sandstones; however, the strength of finer-grained mudrocks is inversely related to the total percentage of clay minerals. Correlations have been established between the deterioration or slaking behaviour of mudrocks in water and their clay mineral content, based on either simple immersion tests or on more sophisticated slake durability index determinations. These relationships may be of significance in understanding the longer-term behaviour of rock strata when exposed in different types of mining operations. The propensity of different rocks to ignite methane in underground mines by frictional effects has also been shown to depend on the mineralogy of the rock materials, whether determined by point counting of thin sections or by Rietveld-based XRD analysis. Abundant quartz, feldspar, and rock fragments in sandstones, for example, increase the likelihood of frictional ignitions, whereas clay minerals and (especially) carbonates in the rock reduce the frictional ignition potential. Pyrite in the rocks, if present, also increases the ignition risk; pyrite undergoes exothermic oxidation at high temperatures whereas other minerals respond by simple heating due to rock-on-rock or pick-on-rock friction processes. (author)

  9. Acoustic emission measurements in petroleum-related rock mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Unander, Tor Erling

    2002-07-01

    Acoustic emission activity in rock has usually been studied in crystalline rock, which reflects that rock mechanics has also mostly been occupied with such rocks in relations to seismology, mining and tunneling. On the other hand, petroleum-related rock mechanics focuses on the behaviour of sedimentary rock. Thus, this thesis presents a general study of acoustic emission activity in sedimentary rock, primarily in sandstone. Chalk, limestone and shale have also been tested, but to much less degree because the AE activity in these materials is low. To simplify the study, pore fluids have not been used. The advent of the personal computer and computerized measuring equipment have made possible new methods both for measuring and analysing acoustic emissions. Consequently, a majority of this work is devoted to the development and implementation of new analysis techniques. A broad range of topics are treated: (1) Quantification of the AE activity level, assuming that the event rate best represents the activity. An algorithm for estimating the event rate and a methodology for objectively describing special changes in the activity e.g., onset determination, are presented. (2) Analysis of AE waveform data. A new method for determining the source energy of an AE event is presented, and it is shown how seismic source theory can be used to analyze even intermediate quality data. Based on these techniques, it is shown that a major part of the measured AE activity originates from a region close to the sensor, not necessarily representing the entire sample. (3) An improved procedure for estimating source locations is presented. The main benefit is a procedure that better handles arrival time data with large errors. Statistical simulations are used to quantify the uncertainties in the locations. The analysis techniques are developed with the application to sedimentary rock in mind, and in two articles, the techniques are used in the study of such materials. The work in the first

  10. Fluids in metamorphic rocks

    NARCIS (Netherlands)

    Touret, J.L.R.

    2001-01-01

    Basic principles for the study of fluid inclusions in metamorphic rocks are reviewed and illustrated. A major problem relates to the number of inclusions, possibly formed on a wide range of P-T conditions, having also suffered, in most cases, extensive changes after initial trapping. The

  11. Rock support design

    Energy Technology Data Exchange (ETDEWEB)

    Vandewalle, M. [N.V. Bekaert (Belgium)

    1999-02-01

    Steel fibre imparts to concrete and shotcrete a high degree of ductibility which not only allow the linings to absorb rock movement but also increases its bearing capacity by a redistribution of the loads. The article discusses the variety of uses of shotcrete for support of underground excavations, mainly for support of permanent mine openings such as ramps, haulages, shaft stations and crusher chambers.

  12. The River Rock School.

    Science.gov (United States)

    Gereaux, Teresa Thomas

    1999-01-01

    In the early 1920s, the small Appalachian community of Damascus, Virginia, used private subscriptions and volunteer labor to build a 15-classroom school made of rocks from a nearby river and chestnut wood from nearby forests. The school building's history, uses for various community activities, and current condition are described. (SV)

  13. Reducing Rock Climbing Risks.

    Science.gov (United States)

    Attarian, Aram

    1998-01-01

    Provides checklists that can be used as risk-management tools to evaluate rock-climbing programs: developing goals, policies, and procedures; inspecting the climbing environment; maintaining and inspecting equipment; protecting participants; and managing staff (hiring, training, retraining, and evaluating) and campers (experience level, needs, and…

  14. Umhlanga Rocks coastal defense

    NARCIS (Netherlands)

    De Jong, L.; De Jong, B.; Ivanova, M.; Gerritse, A.; Rietberg, D.; Dorrepaal, S.

    2014-01-01

    The eThekwini coastline is a vulnerable coastline subject to chronic erosion and damage due to sea level rise. In 2007 a severe storm caused major physical and economic damage along the coastline, proving the need for action. Umhlanga Rocks is a densely populated premium holiday destination on the

  15. Testing the effectiveness of certainty scales, cheap talk, and dissonance-minimization in reducing hypothetical bias in contingent valuation studies

    Science.gov (United States)

    Mark Morrison; Thomas C. Brown

    2009-01-01

    Stated preference methods such as contingent valuation and choice modeling are subject to various biases that may lead to differences between actual and hypothetical willingness to pay. Cheap talk, follow-up certainty scales, and dissonance minimization are three techniques for reducing this hypothetical bias. Cheap talk and certainty scales have received considerable...

  16. Sedimentary basin analysis and petroleum potential of the Cretaceous and Tertiary strata in Korea.

    Energy Technology Data Exchange (ETDEWEB)

    Son, Jin-Dam; Kwak, Young-Hoon; Bong, Pil-Yoon [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

    1999-12-01

    Since 1992 sedimentary basin analysis to assess petroleum potential of the Cretaceous and Tertiary strata in the Korean onshore and continental shelf have been carried out. The Cretaceous non-marine strata mainly occupy the Gyeongsang Basin in southeastern part of the Korean Peninsula and small basins such as Haenam and Gyeokpo depressions in western coastal areas. The Tertiary strata are mostly distributed in Domi, Cheju, Socotra subbasins, and Okinawa Trough in the South Continental Shelf, and Kunsan and Heuksan basins in the West. The basin evolution and petroleum potential for each basins are characterized as follow. The Cretaceous Gyeongsang sediments were deposited in three subbasins including Milyang, Euisung and Yongyang subbasins. The black shales in Nakdong and Jinju formations are interpreted to contain abundant organic matter during the deposition, thermal maturity reaching up to the zone of dry gas formation. Because porosity and permeability are too low, the sandstones can act as a tight gas reservoir rather than conventional oil and gas reservoir. The latest Cretaceous strata of Haenam and Kyeokpo depressions in western coastal area are correlated into the Yuchon Volcanic Group of the Gyeongsang Basin. Petroleum potential of the Early Cretaceous basin in the West Continental Shelf could be relatively high in terms of sedimentary basin filled with thick lacustrine sediments. The Kunsan basin in the West Continental Shelf originated in the Early Cretaceous time expanded during the Paleocene time followed by regional erosion at the end of Paleocene on which Neogene sediment have been accumulated. The Paleocene-Eocene sublacustrine shales may play an major role as a source and cap rocks. South Continental Shelf Basin is subdivided by Cheju subbasin in the center, Socotra Subbasin to the west, Domi Subbasin to the northeast and Okinawa Trough to the East. The potential hydrocarbon traps associated with anticline, titled fault blocks, fault, unconformity

  17. Integrated Provenance Studies in Northwestern South America, Linking Tectonic and Sedimentary Processes

    Science.gov (United States)

    Montes, C.; Cardona, A.; Ramirez, V. O.; Bayona, G.; Ayala, C.; Valencia, V.

    2009-12-01

    Post-collisional late Eocene to Oligocene extensional basins (Plato-San Jorge basin in Colombia) and syn-collisional basins to the east contain the record of drainages and source areas as a former passive margin obliquely collided with the Caribbean deformation front. A 2 to 8 km thick, shallowing-upward and almost entirely fine-grained, upper Eocene and younger sedimentary sequence contains the record of post-collisional paleogeography behind the advancing deformation front. Sedimentation in the syn-collisional margin is fragmentary along the northern margins of Colombia and Venezuela in the Guajira province. An integrated provenance approach is being undertaken with detrital zircon geochronology, whole rock geochemistry, heavy mineral analysis and tectonic modeling. Source areas contain distinctive assemblages that should be diagnostic and include cratonic contributions with Grenville and older provinces, Andean contributions with Mesozoic-age signatures and Caribbean contributions with latest Cretaceous and Paleogene contributions. The complex Paleogene tectonic interactions along the northwestern South American margin include the simultaneous opening of basins (Plato-San Jorge basin in Colombia), micro-block rotation (Santa Marta massif), shortening and mountain building (Perija range) and oblique accretionary wedges along the margin (Sinu-San Jacinto deformed belts). Rivers draining the interior of South America to the north would have been deflected by this Paleogene configuration, and local drainages would have similarly developed in response to changing depocenters. Distinctive signatures should have developed in the sedimentary sequence as the sources dynamically changed from cratonic (Grenville and older cratonic) to Andean (Mesozoic continental crust and reworked) to Caribbean (volcanic arcs and collision zones).

  18. Assessment of Limnigraph Data Usefulness for Determining The Hypothetical Flood Waves with The Cracow Method

    Directory of Open Access Journals (Sweden)

    Gądek Wiesław

    2014-07-01

    Full Text Available In our country the data related to the flow volume in the watercourses is recorded in three database systems: water-gauge, limnigraph and telemetric (digital one. In each of those systems the flow value is presented in a different way. The aim of this publication is to present how the non-compliance of the meaning and substantive difference of water-gauge data and limnigraph data influences on the example of 7 hypothetical floods determined by the Cracow method. Cracow method was initially known as Cracow Technical University Method. The received results show that the limnigraph data does not effect significantly the parameters of the hypothetical floods. In absence of the data from the telemetric system, such analysis has not be done.

  19. Tectonic Models for the Evolution of Sedimentary Basins

    NARCIS (Netherlands)

    Cloetingh, S.|info:eu-repo/dai/nl/069161836; Ziegler, P.A.; Beekman, F.|info:eu-repo/dai/nl/123556856; Burov, E.B.; Garcia-Castellanos, D.; Matenco, L.|info:eu-repo/dai/nl/163604592

    2015-01-01

    The tectonic evolution of sedimentary basins is the intrinsic result of the interplay between lithospheric stresses, lithospheric rheology, and thermal perturbations of the lithosphere–upper mantle system. The thermomechanical structure of the lithosphere exerts a prime control on its response to

  20. Tracing Tectonic Deformation using the Sedimentary Record: an overview.

    NARCIS (Netherlands)

    McCann, T.; Saintot, A.N.

    2003-01-01

    Tectonic activity, on a range of scales, is a fundamental control on sedimentary activity. The range of structural deformation within a region extends from the plate tectonic scale, governing, for example, rift initiation, to the basin scale, with the formation of basin-bounding faults. Internal

  1. Application of GPR in the study of shallow subsurface sedimentary ...

    Indian Academy of Sciences (India)

    This Ground-Penetrating Radar (GPR) survey delineated a variety of the radar surfaces and radar facies which reflects not only large scale sedimentary architecture, but depositional facies of the beach ridge complex. These are bounding surfaces separating the radar facies outline beach ridge (br), washover (wo), coastal ...

  2. Application of GPR in the study of shallow subsurface sedimentary ...

    Indian Academy of Sciences (India)

    The internal sedimentary structures like tangential, parallel, concave and convex upward stratifications could also be visualized from the GPR profiles. The architecture suggests the formation of this complex due to a combined process of eastward littoral drift of locally derived ... distinct depositional energy domains that have.

  3. Sedimentary characteristics of samples collected from some submarine canyons

    NARCIS (Netherlands)

    Bouma, Arnold H.

    Oriented rectangular cores of 20.3 × 30.5 cm and 45.7 cm high have been collected in a number of submarine canyons off southern California (U.S.A.) and off the southern tip of Baja California (Mexico) for a detailed study of their sedimentary structures. By applying several methods, mainly X-ray

  4. Sedimentary strata in the southern highlands of Noachis Terra, Mars

    Science.gov (United States)

    Fenton, L. K.

    2005-12-01

    The sedimentary history of Mars is one of the fundamental problems that needs to be understood in order to determine the role of the atmosphere, climate, and water in sculpting the martian surface. To begin addressing this issue, a number of sedimentary strata, some up to several hundreds of meters thick, have been studied in the southern highlands of Mars using THEMIS VIS and IR (both day and night) images. A sequence of sedimentary units was found in a pit eroded into the floor of Rabe Crater (35° E, 44° S), some of which appear to be shedding dark sand that feeds into the Rabe Crater dune field. The visible and thermal characteristics of these units are similar to other units found across Noachis Terra (which extends from 0°-60° E, 30°-65° S, and includes Rabe Crater), leading to the hypothesis that a series of region-wide depositional events occurred at some point in the martian past, and that these deposits are currently exposed by erosion in pits on crater floors and possibly on the intercrater plains separating the craters. Some of these sedimentary units may consitute a source of sand for the many intracrater dune fields in Noachis Terra, eroding from a widespread source that outcrops locally. Sand-bearing layers that extend across all or part of Noachis Terra are not likely to be dominated by loess or lacustrine deposits; glacial and/or volcanic origins are more plausible.

  5. Using the design of simulation experiments to failures interactive effects analysis in process: a hypothetical case

    OpenAIRE

    Fabiano Leal; Dagoberto Alves De Almeida; José Arnaldo Barra Montevechi; Fernando Augusto Silva Marins

    2007-01-01

    This work presents a failures interactive effects analysis in a process, by means ofsimulations experiments. The chosen process is a hypothetical system, simulated throughsoftware Promodel®. Two conceptual models are generated, representing the system(mapping process) and the failures considered in system (Fault Tree Analysis). Theseconceptual models are translated in a computerized model, for the analysis of individual andcombined effects on the variable “number of produced pieces”. This exp...

  6. Geochemical investigation of petroleum source rocks by using Rock- Eval data in the Agha-Jari oilfield

    Directory of Open Access Journals (Sweden)

    Behzad khani

    2015-01-01

    Full Text Available In this study, 40 drilling cutting of the Pabdeh, Gurpi, kazhdumi and Gadvan Formations from the Agha-Jari Oilfield were analyzed by using Rock-Eval pyrolysis. In order to recognizing sedimentary environmental conditions of studied Formations, they are divided to 4 zones which A (Kazhdumi Formation#187 and C (Kazhdumi Formation#140 zones show reduction conditions by presence of sea organic materials and B (Gadvan Formation #140 and D(Gadvan Formation#187 zones show oxidation conditions by presence of continental organic materials to basin. Based on the Rock-Eval pyrolysis data, the Pabeh, Gurpi, Kazhdumi and Gadvan Formations have variable hydrocarbon generative potential. HI vs. OI plot revealed that the kerogen type in this Formations is a mixed of types II & III. The intensity of matrix effect in the Pabdeh, Gurpi, Kazhdumi and Gadvan Formations was compared by using S2 vs. TOC plot and calculating its regression equation. The results show that the significant amount of S2 adsorption by matrix was happened in the Pabdeh (4.98-6.96 mg HC/gr rock in wells 113 and 121 and Gurpi Formations ‌(4.33 mg HC/gr rock in well 113 which is due to their low thermal maturity‌(Tmax

  7. Upper Cretaceous source rocks of northern and northwestern South America

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, S.; Gallango, O.; Cassani, F.; Vallejos, C.

    1989-03-01

    Organic carbon-rich, laminated, calcareous shales and limestones of Cenomanian to Campanian age are widespread in the polyhistory basins of Venezuela, Colombia, and Trinidad and are identified as the most important oil-generating source rocks in these basins. Available data on sedimentological, geochemical, and organic petrographic characteristics demonstrate that these source rocks are characterized by predominantly marine organic matter deposited in anoxic to near-anoxic marine environments. Marine transgressions due to eustatic sea level rise, with consequent flooding of available shelves of the northern and northwestern passive margin of the Cretaceous South American continent and resulting upwelling conditions, appears to be the key geologic control for the deposition of these laterally extensive source rocks. Significant vertical variations in geochemical properties are observed. These variations were caused by temporal changes in the influx of terrestrial organic matter and/or alternations of relatively oxic and anoxic conditions. Regional variations in organic carbon content, organic matter type, and oil potential broadly reflect the paleogeographic setting of the Cretaceous continental margin. The regionally extensive oil-prone source rocks became largely mature for hydrocarbon generation during the Tertiary, consequent to the development of the individual polyhistory basins. Rock-Eval pyrolysis data from several samples and results from hydrous pyrolysis experiments on some selected immature samples from the Venezuelan basins are used to define the oil-generating capacity, and kinetic parameters obtained from Rock-Eval experiments on the same samples are considered to outline the oil generation under the geological heating rates encountered in the sedimentary basins.

  8. LC-MS/MS based proteomic analysis and functional inference of hypothetical proteins in Desulfovibrio vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weiwen; Culley, David E.; Gritsenko, Marina A.; Moore, Ronald J.; Nie, Lei; Scholten, Johannes C.; Petritis, Konstantinos; Strittmatter, Eric F.; Camp, David G.; Smith, Richard D.; Brockman, Fred J.

    2006-11-03

    ABSTRACT In the previous study, the whole-genome gene expression profiles of D. vulgaris in response to oxidative stress and heat shock were determined. The results showed 24-28% of the responsive genes were hypothetical proteins that have not been experimentally characterized or whose function can not be deduced by simple sequence comparison. To further explore the protecting mechanisms employed in D. vulgaris against the oxidative stress and heat shock, attempt was made in this study to infer functions of these hypothetical proteins by phylogenomic profiling along with detailed sequence comparison against various publicly available databases. By this approach we were ableto assign possible functions to 25 responsive hypothetical proteins. The findings included that DVU0725, induced by oxidative stress, may be involved in lipopolysaccharide biosynthesis, implying that the alternation of lipopolysaccharide on cell surface might service as a mechanism against oxidative stress in D. vulgaris. In addition, two responsive proteins, DVU0024 encoding a putative transcriptional regulator and DVU1670 encoding predicted redox protein, were sharing co-evolution atterns with rubrerythrin in Archaeoglobus fulgidus and Clostridium perfringens, respectively, implying that they might be part of the stress response and protective systems in D. vulgaris. The study demonstrated that phylogenomic profiling is a useful tool in interpretation of experimental genomics data, and also provided further insight on cellular response to oxidative stress and heat shock in D. vulgaris.

  9. The Ability of Children With Language Impairment to Dissemble Emotions in Hypothetical Scenarios and Natural Situations.

    Science.gov (United States)

    Brinton, Bonnie; Fujiki, Martin; Hurst, Noel Quist; Jones, Emily Rowberry; Spackman, Matthew P

    2015-10-01

    This study examined the ability of children with language impairment (LI) to dissemble (hide) emotional reactions when socially appropriate to do so. Twenty-two children with LI and their typically developing peers (7;1-10;11 [years;months]) participated in two tasks. First, participants were presented with hypothetical scenarios in which the main character was exposed to situations that would require dissembling an emotional reaction for social purposes (e.g., receiving a disappointing gift from a grandparent). In the second task, children were presented with four naturally occurring opportunities to dissemble emotion (e.g., receiving a disappointing reward for taking part in the study). Although the ability to dissemble emotion was still emerging in children in both groups, typically developing children judged that dissemblance was appropriate significantly more often than did children with LI in the hypothetical scenarios. In naturalistic scenarios, there was little difference between groups in low-cost scenarios (those in which the child had nothing to lose by hiding emotion). In the high-cost scenario (hiding emotion meant accepting a disappointing prize), more typically developing children concealed their disappointment than did children with LI. These differences neared statistical significance (p = .058). Children with typically developing language showed a greater ability to dissemble in hypothetical scenarios. In naturalistic scenarios, performance was more nuanced. In low-cost scenarios, there was little difference between groups. In the high-cost scenario, typically developing children tended to dissemble more often than did children with LI.

  10. Excessive Gestational Weight Gain and Subsequent Maternal Obesity at Age 40: A Hypothetical Intervention.

    Science.gov (United States)

    Abrams, Barbara; Coyle, Jeremy; Cohen, Alison K; Headen, Irene; Hubbard, Alan; Ritchie, Lorrene; Rehkopf, David H

    2017-09-01

    To model the hypothetical impact of preventing excessive gestational weight gain on midlife obesity and compare the estimated reduction with the US Healthy People 2020 goal of a 10% reduction of obesity prevalence in adults. We analyzed 3917 women with 1 to 3 pregnancies in the prospective US National Longitudinal Survey of Youth, from 1979 to 2012. We compared the estimated obesity prevalence between 2 scenarios: gestational weight gain as reported and under the scenario of a hypothetical intervention that all women with excessive gestational weight gain instead gained as recommended by the Institute of Medicine (2009). A hypothetical intervention was associated with a significantly reduced estimated prevalence of obesity for first (3.3 percentage points; 95% confidence interval [CI] = 1.0, 5.6) and second (3.0 percentage points; 95% CI = 0.7, 5.2) births, and twice as high in Black as in White mothers, but not significant in Hispanics. The population attributable fraction was 10.7% (95% CI = 3.3%, 18.1%) in first and 9.3% (95% CI = 2.2%, 16.5%) in second births. Development of effective weight-management interventions for childbearing women could lead to meaningful reductions in long-term obesity.

  11. Monitoring the sedimentary carbon in an artificially disturbed deep-sea sedimentary environment.

    Science.gov (United States)

    Nath, B Nagender; Khadge, N H; Nabar, Sapana; Raghukumar, Chandralata; Ingole, B S; Valsangkar, A B; Sharma, Rahul; Srinivas, K

    2012-05-01

    An area of 0.6 km(2) in the manganese nodule field of the Central Indian Basin was physically disturbed and sediments discharged in the near bottom waters to simulate seabed mining and study its impact on benthic ecosystem. An estimated 2 to 3 tonnes of sedimentary organic carbon (C(org)) was resuspended into the water column during a 9-day experiment. The majority of the sediment cores from within the disturbed area and areas towards the south showed a ~30% increase in C(org) content as well as an increase in carbon burial rates after disturbance, though with a reduction in carbon/phosphorus ratios. High specific surface area (SSA~25 m(2) g(-1)) and low C(org)/SSA ratios (mostly <0.5) are typical of deep-sea sediments. The increased C(org) values were probably due to the organic matter from dead biota and the migration and redeposition of fine-grained, organic-rich particles. Spatial distribution patterns of C(org) contents of cores taken before and after disturbance were used to infer the direction of plume migration and re-sedimentation. A positive relationship was observed between total and labile C(org) and macrobenthos density and total bacterial numbers prior to disturbance, whereas a negative relationship was seen after disturbance owing to drastic reduction in the density of macrofauna and bacteria. Overall decrease in labile organic matter, benthic biota and redistribution of organic matter suggest that the commercial mining of manganese nodules may have a significant immediate negative effect on the benthic ecosystem inducing changes in benthic community structure.

  12. The post-Laramide clastic deposits of the Sierra de Guanajuato: Compositional implications on the tectono-sedimentary and paleographic evolution

    Directory of Open Access Journals (Sweden)

    R. Miranda-Avilés

    2016-11-01

    Full Text Available This article presents the results of the study on sedimentation, sedimentary environments, tectono-sedimentary and paleogeographic evolution of post-Laramide clastic deposits and pre-volcanism of the Sierra Madre Occidental in the Sierra de Guanajuato, central Mexico. The Eocene Duarte Conglomerate and Guanajuato Conglomerate were deposited in the middle and distal parts of alluvial fans. The studied rocks are composed of limestone clasts, granite, andesite, metasediments, diorite, and pyroxenite, indicating the erosion of uplifted blocks of the basal complex of the Sierra de Guanajuato (Arperos basin. The petrographic and compositional analysis of limestone shows a textural variation from basin limestones and shallow platform limestones. The shallow platform limestone contain bivalves, brachiopods, gastropods, echinoderms and benthic foraminifera from the Berriasian-Valanginian. The shallow-water limestone corresponds to the boundary of the Arperos basin whose original outcrops currently not outcrop in the Sierra de Guanajuato.

  13. The post-Laramide clastic deposits of the Sierra de Guanajuato: Compositional implications on the tectono-sedimentary and paleographic evolution

    Energy Technology Data Exchange (ETDEWEB)

    Miranda-Aviles, R.; Puy-Alquiza, M.J.; OmaNa, L.; Loza-Aguirre, I.

    2016-07-01

    This article presents the results of the study on sedimentation, sedimentary environments, tectono-sedimentary and paleogeographic evolution of post-Laramide clastic deposits and pre-volcanism of the Sierra Madre Occidental in the Sierra de Guanajuato, central Mexico. The Eocene Duarte Conglomerate and Guanajuato Conglomerate were deposited in the middle and distal parts of alluvial fans. The studied rocks are composed of limestone clasts, granite, andesite, metasediments, diorite, and pyroxenite, indicating the erosion of uplifted blocks of the basal complex of the Sierra de Guanajuato (Arperos basin). The petrographic and compositional analysis of limestone shows a textural variation from basin limestones and shallow platform limestones. The shallow platform limestone contain bivalves, brachiopods, gastropods, echinoderms and benthic foraminifera from the Berriasian-Valanginian. The shallow-water limestone corresponds to the boundary of the Arperos basin whose original outcrops currently not outcrop in the Sierra de Guanajuato. (Author)

  14. Rock critics as 'Mouldy Modernists'

    OpenAIRE

    Shepherd, Becky

    2011-01-01

    Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly,...

  15. STXM-NEXAFS measurements of rock varnish, investigating element distributions and carbon occurrences in the Mn-rich rock coating

    Science.gov (United States)

    Macholdt, D.; Pöhlker, C.; Jochum, K. P.; Förster, J. D.; Weber, B.; Kilcoyne, A. L. D.; Weigand, M.; Müller, M.; Kappl, M.; Scholz, D.; Haug, G. H.; Andreae, M. O.

    2016-12-01

    Rock varnish, a black, Mn-rich sedimentary coating on rock surfaces, has been a matter of debate for many decades. Manganese oxyhydroxides and mineral dust are the major components of this material, whose genesis remains highly controversial. A biogenic compound was proposed by several researchers as an inducer and initiator of the gradual growth of up to 250 µm thick varnish layers. To finally unravel this mystery, we employed several cutting-edge techniques. One of the techniques that proved to be effective in investigating rock varnish is scanning transmission X-ray microscopy-near-edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS) on focused ion beam (FIB) ultra-thin sections (100-200 nm) of layered rock varnishes. With these measurements, which were conducted at two synchrotron facilities providing soft X-rays [Advanced Light Source (ALS) in Berkeley and BESSY II in Berlin], nm-sized structures can be observed by element distribution mapping. To this end, we utilized two microscopes, one at beamline 5.3.2.2 at the ALS, and the MAXYMUS microscope at beamline UE46-PGM-2 at BESSY II. Carbon abundances and bonds were examined in detail, and the oxidation states of Mn and Fe were determined. We observed layered sequences of Mn- and Fe-rich layers in several varnishes, which are thought to represent wet and dry climate episodes. Element abundance changes of K and Ca between different layers, and mineral grain sizes and shapes are of interest to evaluate changing dust compositions over time. Carbon distribution maps can help to verify biogenic activity during the genesis, and Mn- and Fe-oxidation states reveal changes within single rock varnishes. Therefore, results of this research combined with results of other state-of-the-art microanalytical techniques provide important and detailed information that might help to resolve the question about the genesis of rock varnish, and its applicability as paleoclimate archive for desert environments.

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

    Science.gov (United States)

    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. Rock burst governance of working face under igneous rock

    Science.gov (United States)

    Chang, Zhenxing; Yu, Yue

    2017-01-01

    As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

  18. Stratigraphic position, origin and characteristics of manganese mineralization horizons in the Late Cretaceous volcano-sedimentary sequence, south-southwest of Sabzevar

    Directory of Open Access Journals (Sweden)

    Sajjad Maghfouri

    2014-10-01

    Full Text Available Introduction The Mn mineralization occurs in the northeastern segment of the Sabzevar zone (SZ, north of the Central Iranian Microcontinent (CIM. This Zone (SZ is located between the CIM fragmentation in the south and the Kopeh dagh sedimentary sequence in the north. The ore deposits of the northeastern segment of the Sabzevar zone can be divided into three groups, each with different metal association and spatial distribution and each related to a major geodynamic event. The first mineralization with associated Ordovician host rock is characterized by Taknar polymetallic (Fe-rich massive sulfide deposit. The Cretaceous mineralization consists of Cr deposits associated with serpentinized peridotites, Cyprus type VMS, Mn deposit in pillow lava, volcano-sedimentary hosted Besshi type VMS and Mn deposit. Paleogene mineralization in eastern segment of the Sabzevar zone began with porphyry deposits, Cu Red Bed mineralization occurs in the Paleogene sandy red marl. Materials and methods A field study and sampling was performed during the autumn of 2012. To assess the geochemical characteristics of 48 systematic samples (least fractured and altered of ore-bearing layers and host rocks were collected from the deposit for polished thin section examination. In order to correctly characterize their chemical compositions, 15 least-altered and fractured samples were chosen for major elements analysis. Results The Late Cretaceous volcano-sedimentary sequence in south-southwest of Sabzevar hosts numerous manganese mineralization. The sequence based on the stratigraphic position, age and composition of the rocks, can be divided into two lower and upper parts. The lower part or K2tv unit mainly formed from marine sediments interbedded with volcanic rocks. The sedimentary rocks of this part include silicified tuff, chert, shale and sandstone, and the volcanic rocks involve pyroclastic rocks of various composition, rhyolite, dacite and andesitic lava. The upper

  19. Rock and mineral magnetism

    CERN Document Server

    O’Reilly, W

    1984-01-01

    The past two decades have witnessed a revolution in the earth sciences. The quantitative, instrument-based measurements and physical models of. geophysics, together with advances in technology, have radically transformed the way in which the Earth, and especially its crust, is described. The study of the magnetism of the rocks of the Earth's crust has played a major part in this transformation. Rocks, or more specifically their constituent magnetic minerals, can be regarded as a measuring instrument provided by nature, which can be employed in the service of the earth sciences. Thus magnetic minerals are a recording magnetometer; a goniometer or protractor, recording the directions of flows, fields and forces; a clock; a recording thermometer; a position recorder; astrain gauge; an instrument for geo­ logical surveying; a tracer in climatology and hydrology; a tool in petrology. No instrument is linear, or free from noise and systematic errors, and the performance of nature's instrument must be assessed and ...

  20. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  1. Identification of Rocks and Their Quartz Content in Gua Musang Goldfield Using Advanced Spaceborne Thermal Emission and Reflection Radiometer Imagery

    Directory of Open Access Journals (Sweden)

    Kouame Yao

    2017-01-01

    Full Text Available Quartz is an important mineral element and the most abundant rock-forming mineral that controls the mineralogy of a reservoir. At the surface, quartz is more stable than most other rock minerals because it is made up of interlocking silica that makes it quite resistant to mechanical weathering. Quartz abundance is an indication of mineralization in many metal deposits; therefore, identification and mapping of quartz in rocks are of great value for exploration and resource potential assessments. In this study, thermal infrared (TIR bands of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER imagery were used to identify quartz contained rocks in Gua Musang. First, the image was corrected for atmospheric effect and the study area subset for further processing. Thereafter, spectral transformation (principal component analysis (PCA was implemented on the TIR bands and the resulting principal component (PC images were analysed. The three optimal PCs were selected using the strength of spectral interaction and the eigenvalues of each band. To discriminate between quartz-rich and quartz-poor rocks, RGB false colour composite and greyscale image of one of the PCs were analysed. The result shows that volcanogenic igneous rock and carbonate sedimentary rocks of Permian formation are quartz-poor while Triassic sedimentary rock made up of organic particles and sandstone is quartz-rich. On the contrary, the quartz content in the metamorphic rock varies across the area but is richer in quartz content than the igneous and carbonate rocks. Classification of the composite image classified using maximum likelihood (ML supervised classification method produced overall accuracy and Kappa coefficient of 96.53%, and 0.95, respectively.

  2. Limados : Rock peruano

    OpenAIRE

    García Morete, Ramiro

    2013-01-01

    Incentivado por la corriente nuevaolera que llegaba de México, fue señalado por especialistas como pionero del punk. Aunque el plan, era tocar con lo que hubiera. Un recodo ínfimo de un período breve pero sorprendentemente poderoso, los 60 en un país que hizo del rock una expresión propia de su cultura. Facultad de Periodismo y Comunicación Social

  3. Rock pushing and sampling under rocks on Mars

    Science.gov (United States)

    Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

    1978-01-01

    Viking Lander 2 acquired samples on Mars from beneath two rocks, where living organisms and organic molecules would be protected from ultraviolet radiation. Selection of rocks to be moved was based on scientific and engineering considerations, including rock size, rock shape, burial depth, and location in a sample field. Rock locations and topography were established using the computerized interactive video-stereophotogrammetric system and plotted on vertical profiles and in plan view. Sampler commands were developed and tested on Earth using a full-size lander and surface mock-up. The use of power by the sampler motor correlates with rock movements, which were by plowing, skidding, and rolling. Provenance of the samples was determined by measurements and interpretation of pictures and positions of the sampler arm. Analytical results demonstrate that the samples were, in fact, from beneath the rocks. Results from the Gas Chromatograph-Mass Spectrometer of the Molecular Analysis experiment and the Gas Exchange instrument of the Biology experiment indicate that more adsorbed(?) water occurs in samples under rocks than in samples exposed to the sun. This is consistent with terrestrial arid environments, where more moisture occurs in near-surface soil un- der rocks than in surrounding soil because the net heat flow is toward the soil beneath the rock and the rock cap inhibits evaporation. Inorganic analyses show that samples of soil from under the rocks have significantly less iron than soil exposed to the sun. The scientific significance of analyses of samples under the rocks is only partly evaluated, but some facts are clear. Detectable quantities of martian organic molecules were not found in the sample from under a rock by the Molecular Analysis experiment. The Biology experiments did not find definitive evidence for Earth-like living organisms in their sample. Significant amounts of adsorbed water may be present in the martian regolith. The response of the soil

  4. Rock in Rio: forever young

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira Freitas

    2014-12-01

    Full Text Available The purpose of this article is to discuss the role of Rock in Rio: The Musical, as herald of megafestival Rock in Rio. Driven by the success that musicals have reached in Brazil, we believe that the design of this spectacle of music, dance and staging renews the brand of the rock festival, once it adds the force of young and healthy bodies to its concept. Moreover, the musical provides Rock in Rio with some distance from the controversal trilogy of sex, drugs and rock and roll, a strong mark of past festivals around the world. Thus, the musical expands the possibilities of growth for the brand.

  5. The effect of a sedimentary wedge on earthquake ground motions: The influence of eastern U.S. Atlantic Coastal Plain strata

    Science.gov (United States)

    Pratt, Thomas; Magnani, Beatrice

    2017-04-01

    Coastal regions of the eastern U.S. are underlain by a wedge of partially consolidated Atlantic Coastal Plain (ACP) marine sedimentary strata overlying a bedrock of crystalline or indurated sedimentary rocks. The ACP strata extend more than 200 km inland, tapering landward from as much as 1 km near the coast. Unconsolidated, shallow sedimentary strata strongly influence earthquake ground motions due to low seismic impedance and strong reflections from the bedrock contact. Site response estimates primarily determine high-frequency amplifications from shear-wave velocities in the upper 30 m (Vs30), but thicker sedimentary sequences can increase longer-period ground motions important to large structures. Here we use data from continental-scale seismic experiments that span the ACP (e.g. Eastern North America Margin [ENAM], Earthscope Transportable Array) to examine the influence of ACP strata on earthquake ground motions. We use teleseismic and regional earthquake recordings to compute spectral ratios relative to bedrock sites. Thin ACP strata produce fundamental resonance peaks at high frequencies (>5 Hz), but the fundamental peaks decrease to about 0.45 Hz as the sediments thicken to about 500 m. Amplitudes of the fundamental resonance peaks decrease as the strata thicken, but even coastal sites show amplification factors as great as 5. In addition, we use the frequency of the resonance peaks to invert for an average velocity function within the ACP strata. A smaller array within the city of Washington, DC, which is underlain by a wedge 0- to 270-m-thick ACP strata, shows large amplifications at frequencies of 0.7 to 5 Hz. These amplifications likely contributed to the widespread damage to the city during the relatively modest, M5.8 Virginia earthquake in 2011. This work confirms amplification of short-period ground motions by thin ACP strata, and documents longer-period amplifications caused by thick sedimentary sequences beneath coastal regions of the eastern U.S.

  6. Oil(Gas) - source rock correlation technique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The overview of bio-marker parameters which are applicable to hydrocarbon exploration has been illustrated. Experimental analysis of saturated hydrocarbon and bio-markers of the Pohang E and F core samples has been carried out. Samples were extracted by stirring in dichloromethane at 40-50 degree for 10 hours. The saturated, aromatic and resin fractions of the extract were obtained using thin layer chromatograms. The relative abundance of normal alkane fraction of the samples is low except lowest interval, which is probably due to the biodegradation. The bio-marker assemblage of hopanoids and steranes has been characterized. According to the analysis of saturated hydrocarbons and bio-markers, the sedimentary environment of the Pohang core samples is marine and transitional zone except the terrestrial environment of the lowest samples such as 610.5 m from E core and 667.2 m from F core. The thermal maturity through the studied interval did not reach oil window even though slight increase in thermal maturity with depth, which coincide with Rock Eval pyrolysis data. In order to check the validation of analysis of the bio-markers, same samples were analyzed by the University of Louis Pasteur, France. The distribution and relative peak area of the bio-markers were identical with those by laboratory of KIGAM. For the 2 nd stage of the research, analysis of bio-markers other than hopanoids and steranes should be continued. (author). 29 figs., 7 tabs.

  7. Correlating P-wave Velocity with the Physico-Mechanical Properties of Different Rocks

    Science.gov (United States)

    Khandelwal, Manoj

    2013-04-01

    In mining and civil engineering projects, physico-mechanical properties of the rock affect both the project design and the construction operation. Determination of various physico-mechanical properties of rocks is expensive and time consuming, and sometimes it is very difficult to get cores to perform direct tests to evaluate the rock mass. The purpose of this work is to investigate the relationships between the different physico-mechanical properties of the various rock types with the P-wave velocity. Measurement of P-wave velocity is relatively cheap, non-destructive and easy to carry out. In this study, representative rock mass samples of igneous, sedimentary, and metamorphic rocks were collected from the different locations of India to obtain an empirical relation between P-wave velocity and uniaxial compressive strength, tensile strength, punch shear, density, slake durability index, Young's modulus, Poisson's ratio, impact strength index and Schmidt hammer rebound number. A very strong correlation was found between the P-wave velocity and different physico-mechanical properties of various rock types with very high coefficients of determination. To check the sensitivity of the empirical equations, Students t test was also performed, which confirmed the validity of the proposed correlations.

  8. The volcano-sedimentary succession of Upper Permian in Wuli area, central Qinghai-Tibetan Plateau: Sedimentology, geochemistry and paleogeography

    Science.gov (United States)

    Liu, Shengqian; Jiang, Zaixing; Gao, Yi

    2017-04-01

    Detailed observations on cores and thin sections well documented a volcano-sedimentary succession from Well TK2, which is located in Wuli area, central Qinghai-Tibetan Plateau. The TK2 volcano-sedimentary succession reflects an active sedimentary-tectonic setting in the north margin of North Qiangtang-Chamdo terrane in the late Permian epoch. Based on the observation and recognition on lithology and mineralogy, the components of TK2 succession are mainly volcanic and volcaniclastic rocks and four main lithofacies are recognized, including massive volcanic lithofacies (LF1), pyroclastic tuff lithofacies (LF2), tuffaceous sandstone lithofacies (LF3) and mudstone lithofacies (LF4). LF1 is characterized by felsic components, massive structure and porphyrotopic structure with local flow structure, which indicates submarine intrusive domes or extrusion-fed lavas that formed by magma ascents via faults or dykes. Meanwhile, its eruption style may reflect a relative high pressure compensation level (PCL) that mainly determined by water depth, which implies a deep-water environment. LF2 is composed of volcanic lapilli or ash and featured with massive structure, parallel bedding and various deformed laminations including convolve structure, slide deformation, ball-and-pillow structure, etc.. LF2 indicates the sedimentation of initial or reworked explosive products not far away from volcano centers, reflecting the proximal accumulation of volcano eruption-fed clasts or their resedimentation as debris flows. In addition, the submarine volcano eruptions may induced earthquakes that facilitate the resedimentation of unconsolidated sediments. LF3 contains abundant pyroclastic components and is commonly massive with rip-up mudstone clasts or usually interbedded with LF4. In addition, typical flute casts, scour structures and graded beddings in thin-interbedded layers of sandstone and mudstone are commonly observed, which also represents the sedimentation of debris flows or

  9. Geothermal reservoir simulation of hot sedimentary aquifer system using FEFLOW®

    Science.gov (United States)

    Nur Hidayat, Hardi; Gala Permana, Maximillian

    2017-12-01

    The study presents the simulation of hot sedimentary aquifer for geothermal utilization. Hot sedimentary aquifer (HSA) is a conduction-dominated hydrothermal play type utilizing deep aquifer, which is heated by near normal heat flow. One of the examples of HSA is Bavarian Molasse Basin in South Germany. This system typically uses doublet wells: an injection and production well. The simulation was run for 3650 days of simulation time. The technical feasibility and performance are analysed in regards to the extracted energy from this concept. Several parameters are compared to determine the model performance. Parameters such as reservoir characteristics, temperature information and well information are defined. Several assumptions are also defined to simplify the simulation process. The main results of the simulation are heat period budget or total extracted heat energy, and heat rate budget or heat production rate. Qualitative approaches for sensitivity analysis are conducted by using five parameters in which assigned lower and higher value scenarios.

  10. Detecting sedimentary cycles using autocorrelation of grain size.

    Science.gov (United States)

    Xiao, Shangbin; Li, Rui; Chen, Muhong

    2013-01-01

    Detection of sedimentary cycles is difficult in fine-grained or homogenous sediments but is a prerequisite for the interpretation of depositional environments. Here we use a new autocorrelation analysis to detect cycles in a homogenous sediment core, E602, from the northern shelf of the South China Sea. Autocorrelation coefficients were calculated for different mean grain sizes at various depths. The results show that sediments derived from rapid depositional events have a better autocorrelation. Analysis of two other cores confirms this result. Cores composed of sediments deposited quickly under stable and/or gradually changing hydrodynamic conditions, have higher autocorrelation coefficients, whereas, those composed of sediments deposited during calm periods have relatively low autocorrelation coefficients. It shows that abrupt changes in autocorrelation coefficients usually indicate the existence of a boundary between adjacent sedimentary cycles, with each cycle beginning with a high positive autocorrelation coefficient of grain size and ending with a low negative one.

  11. A Backarc Basin Origin for the Eocene Volcanic Rocks North of Abbas Abad, East of Shahrud, Northeast Iran

    Science.gov (United States)

    Khalatbari Jafari, M.; Mobasher, K.; Davarpanah, A.; Babaie, H.; La Tour, T.

    2008-12-01

    The region in northeastern Iran, bordered by the Miami fault and the Doruneh fault, mainly exposes the Eocene volcanic and Tertiary sedimentary rocks and sporadic outcrops of pre- Jurassic metamorphic rocks such as gneiss and mica-schist. We have divided the volcanic and volcanic-sedimentary rocks into six main units: E1 through the youngest E6. North of Abbas Abad, the Lower Eocene is conglomerate, sandstone, and red shale with lenses of nummulite-bearing limestone at the base, and dacitic lava (E1) at the top. The nummulites give an Early Eocene age for the limestone lenses. The E2 unit includes vesicular basalt, intercalated, intraformational conglomerate, and lenses of nummulite-bearing limestone. E3 is volcanic- sedimentary, and is made of green tuff, tuffite, shale, and nummulite bearing limestone. E4 includes basalt and vesicular trachy-basalt, and E5 is mostly sedimentary, made of tan marl, sandstone, shale, and lenses of Middle Eocene nummulite-bearing limestone. The E6 unit is the most extensive, with at least three levels of nummulite-bearing limestone lenses which give a Middle to Early Eocene age. The volcanic rocks of the E6 unit include few hundred meters of epiclastic to hyaloclastic breccia, with intercalations of lava at the base. These are overlain by four horizons of aphyric olivine basalt and basalt, and phyric trachy-andesite and trachy-basalt. The volume of the aphyric lavas decreases, and that of the phyric lavas increases upsection. The Eocene volcanic sequence is covered by turbidite; the marl washings give an Eocene-Oligocene age range. Chondrite-normalized multi-element plots indicate enrichment of the Eocene Abbas Abad volcanic rocks in the LILE elements, with variable ratios of La/Yb (4.36-19.33) and La/Sm (3.10-7.91). These plots show a gentle slope, and the volcanic rocks in the E1 to E4 units are less enriched than those in the E6 unit, probably reflecting the difference in the original source for the melt. The multi-element plots

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

    Science.gov (United States)

    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

  13. The impact of sedimentary coatings on the diagenetic Nd flux

    Science.gov (United States)

    Abbott, April N.; Haley, Brian A.; McManus, James

    2016-09-01

    Because ocean circulation impacts global heat transport, understanding the relationship between deep ocean circulation and climate is important for predicting the ocean's role in climate change. A common approach to reconstruct ocean circulation patterns employs the neodymium isotope compositions of authigenic phases recovered from marine sediments. In this approach, mild chemical extractions of these phases is thought to yield information regarding the εNd of the bottom waters that are in contact with the underlying sediment package. However, recent pore fluid studies present evidence for neodymium cycling within the upper portions of the marine sediment package that drives a significant benthic flux of neodymium to the ocean. This internal sedimentary cycling has the potential to obfuscate any relationship between the neodymium signature recovered from the authigenic coating and the overlying neodymium signature of the seawater. For this manuscript, we present sedimentary leach results from three sites on the Oregon margin in the northeast Pacific Ocean. Our goal is to examine the potential mechanisms controlling the exchange of Nd between the sedimentary package and the overlying water column, as well as the relationship between the εNd composition of authigenic sedimentary coatings and that of the pore fluid. In our comparison of the neodymium concentrations and isotope compositions from the total sediment, sediment leachates, and pore fluid we find that the leachable components account for about half of the total solid-phase Nd, therefore representing a significant reservoir of reactive Nd within the sediment package. Based on these and other data, we propose that sediment diagenesis determines the εNd of the pore fluid, which in turn controls the εNd of the bottom water. Consistent with this notion, despite having 1 to 2 orders of magnitude greater Nd concentration than the bottom water, the pore fluid is still metal results in more radiogenic pore fluid.

  14. Sensitivity Analysis of Evacuation Speed in Hypothetical NPP Accident by Earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung-yeop; Lim, Ho-Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Effective emergency response in emergency situation of nuclear power plant (NPP) can make consequences be different therefore it is regarded important when establishing an emergency response plan and assessing the risk of hypothetical NPP accident. Situation of emergency response can be totally changed when NPP accident caused by earthquake or tsunami is considered due to the failure of roads and buildings by the disaster. In this study evacuation speed has been focused among above various factors and reasonable evacuation speed in earthquake scenario has been investigated. Finally, sensitivity analysis of evacuation speed in hypothetical NPP accident by earthquake has been performed in this study. Evacuation scenario can be entirely different in the situation of seismic hazard and the sensitivity analysis of evacuation speed in hypothetical NPP accident by earthquake has been performed in this study. Various references were investigated and earthquake evacuation model has been developed considering that evacuees may convert their evacuation method from using a vehicle to walking when they face the difficulty of using a vehicle due to intense traffic jam, failure of buildings and roads, and etc. The population dose within 5 km / 30 km have been found to be increased in earthquake situation due to decreased evacuation speed and become 1.5 - 2 times in the severest earthquake evacuation scenario set up in this study. It is not agreed that using same emergency response model which is used for normal evacuation situations when performing level 3 probabilistic safety assessment for earthquake and tsunami event. Investigation of data and sensitivity analysis for constructing differentiated emergency response model in the event of seismic hazard has been carried out in this study.

  15. Radon and its decay product activities in the magmatic area and the adjacent volcano-sedimentary Intrasudetic Basin

    Directory of Open Access Journals (Sweden)

    D. Tchorz

    2007-06-01

    Full Text Available In the magmatic area of Sudetes covering the Karkonosze granite and adjacent volcano-sedimentary Intrasudetic Basin a study of atmospheric radon activity was performed by means of SSNTD Kodak LR-115. The study was completed by gamma spectrometric survey of eU and eTh determined by gamma activity of radon decay products 214Bi and 208Tl respectively. In the case of the western part of the Karkonosze granite area the radon decay products activity in the granitic basement was found to be as high as 343 Bq/kg for 214Bi and 496 Bq/kg for 208Tl respectively. Atmospheric radon content measured by means of Kodak LR115 track detector at the height of 1.5 m was found as high as 70 Bq/m3 in the regions, where no mining activities took place. However in the eastern part of the granitic massif in the proximity of abandoned uranium mine atmospheric radon content was found to be 6000 Bq/m3. In the case of sedimentary basin where sedimentary sequence of Carboniferous rocks has been penetrated by younger gases and fluids of volcanic origin uranium mineralization developed. The region known from its CO2 outburst during coal mining activity is characterized by good ventilation of the uranium enriched geological basement resulting in increased atmospheric radon activity being in average 72 Bq/m3. In the vicinity of coal mine tailing an increase up to 125 Bq/m3 can be observed. Seasonal variations of atmospheric radon content are influenced in agricultural areas by cyclic cultivation works (plough on soils of increased uranium content and in the case of post-industrial brownfields varying rates of radon exhalation from tailings due to different meteorological conditions.

  16. Reducing therapeutic misconception: A randomized intervention trial in hypothetical clinical trials.

    Science.gov (United States)

    Christopher, Paul P; Appelbaum, Paul S; Truong, Debbie; Albert, Karen; Maranda, Louise; Lidz, Charles

    2017-01-01

    Participants in clinical trials frequently fail to appreciate key differences between research and clinical care. This phenomenon, known as therapeutic misconception, undermines informed consent to clinical research, but to date there have been no effective interventions to reduce it and concerns have been expressed that to do so might impede recruitment. We determined whether a scientific reframing intervention reduces therapeutic misconception without significantly reducing willingness to participate in hypothetical clinical trials. This prospective randomized trial was conducted from 2015 to 2016 to test the efficacy of an informed consent intervention based on scientific reframing compared to a traditional informed consent procedure (control) in reducing therapeutic misconception among patients considering enrollment in hypothetical clinical trials modeled on real-world studies for one of five disease categories. Patients with diabetes mellitus, hypertension, coronary artery disease, head/neck cancer, breast cancer, and major depression were recruited from medical clinics and a clinical research volunteer database. The primary outcomes were therapeutic misconception, as measured by a validated, ten-item Therapeutic Misconception Scale (range = 10-50), and willingness to participate in the clinical trial. 154 participants completed the study (age range, 23-87 years; 92.3% white, 56.5% female); 74 (48.1%) had been randomized to receive the experimental intervention. Therapeutic misconception was significantly lower (p = 0.004) in the scientific reframing group (26.4, 95% CI [23.7 to 29.1] compared to the control group (30.9, 95% CI [28.4 to 33.5], and remained so after controlling for education (p = 0.017). Willingness to participate in the hypothetical trial was not significantly different (p = 0.603) between intervention (52.1%, 95% CI [40.2% to 62.4%]) and control (56.3%, 95% CI [45.3% to 66.6%] groups. An enhanced educational intervention augmenting

  17. The Use of the Lexical Exponents of Hypothetical Modality in Polish and Lithuanian

    Directory of Open Access Journals (Sweden)

    Danuta Roszko

    2016-12-01

    Full Text Available The Use of the Lexical Exponents of Hypothetical Modality in Polish and Lithuanian In this article the author focuses on the issue of hypothetical modality[1] in Polish and Lithuanian. A list of the basic exponents of hypothetical modality in both languages is presented. However, the focus is mainly placed on the lexical exponents. On the basis of one of the six groups, which describes a high degree of probability (H5, the differences between the use of the lexical exponents in both languages are examined. In the study, multilingual corpora resources, including The Polish-Lithuanian parallel corpus Clarin-PL., are utilized. [1] [In the academic literature, for the notion described herein, the term of epistemic modality is also used.  Nevertheless, in this paper I will continue to use the term of hypotheticality, which I borrowed from the studies on modality, conducted in Polish-Bulgarian cooperation (Slavic Institute of Polish Academy of Sciences and Institute for Bulgarian Language of the Bulgarian Academy of Sciences.]   O użyciu wykładników leksykalnych modalności hipotetycznej w językach polskim i litewskim W artykule autorka porusza zagadnienie modalności hipotetycznej[1]  w językach polskim i litewskim. Przedstawia wykaz podstawowych wykładników modalności hipotetycznej w obu językach. Główną uwagę skupia jednak na wykładnikach leksykalnych. Na przykładzie jednej z sześciu grup, opisującej wysoki stopień prawdopodobieństwa (H5, omawia różnice użycia wykładników leksykalnych w obu językach. W badaniach wykorzystuje wielojęzyczne zasoby korpusowe, w tym Polsko-litewski korpus równoległy Clarin-PL. [1] [W literaturze przedmiotu na oznaczenie opisywanych tu treści stosowany jest również termin epistemiczności. Niemniej jednak w tej pracy autorka pozostaje przy terminie hipotetyczności, który zapożycza z badań nad modalnością, prowadzonych we współpracy polsko-bułgarskiej (Instytut Slawistyki PAN i

  18. Radiation Dose Calculations for a Hypothetical Accident in Xianning Nuclear Power Plant

    OpenAIRE

    Bo Cao; Junxiao Zheng; Yixue Chen

    2016-01-01

    Atmospheric dispersion modeling and radiation dose calculations have been performed for a hypothetical AP1000 SGTR accident by HotSpot code 3.03. TEDE, the respiratory time-integrated air concentration, and the ground deposition are calculated for various atmospheric stability classes, Pasquill stability categories A–F with site-specific averaged meteorological conditions. The results indicate that the maximum plume centerline ground deposition value of 1.2E+2 kBq/m2 occurred at about 1.4 km ...

  19. A study on the recriticality possibilities of fast reactor cores after a hypothetical core meltdown accident

    Energy Technology Data Exchange (ETDEWEB)

    Na, Byung Chan; Han, Do Hee; Kim, Young Cheol

    1997-04-01

    The preliminary and parametric sensitivity study on recriticality risk of fast reactor cores after a hypothetical total core meltdown accident was performed. Only the neutronic aspects of the accident was considered for this study, independent of the accident scenario. Estimation was made for the quantities of molten fuel which must be ejected out of the core in order to assure a sub-critical state. Diverse parameters were examined: molten pool type (homogenized or stratified), fuel temperature, conditions of the reactor core, core size (small or large), and fuel type (oxide, nitride, metal) (author). 7 refs.

  20. Screening and expression of selected taxonomically conserved and unique hypothetical proteins in Burkholderia pseudomallei K96243

    Science.gov (United States)

    Akhir, Nor Azurah Mat; Nadzirin, Nurul; Mohamed, Rahmah; Firdaus-Raih, Mohd

    2015-09-01

    Hypothetical proteins of bacterial pathogens represent a large numbers of novel biological mechanisms which could belong to essential pathways in the bacteria. They lack functional characterizations mainly due to the inability of sequence homology based methods to detect functional relationships in the absence of detectable sequence similarity. The dataset derived from this study showed 550 candidates conserved in genomes that has pathogenicity information and only present in the Burkholderiales order. The dataset has been narrowed down to taxonomic clusters. Ten proteins were selected for ORF amplification, seven of them were successfully amplified, and only four proteins were successfully expressed. These proteins will be great candidates in determining the true function via structural biology.

  1. Modern sedimentary processes along the Doce river adjacent continental shelf

    Directory of Open Access Journals (Sweden)

    Valéria da Silva Quaresma

    Full Text Available In areas of the continental shelf where sediment supply is greater than the sediment dispersion capacity, an extensive terrigenous deposits and consequently submerged deltas can be formed. The Eastern Brazilian shelf is characterized by the occurrence of river feed deltas in between starving coasts. Herein, modern sedimentary processes acting along the Doce river adjacent continental shelf are investigated. The main objective was to understand the shelf sediment distribution, recognizing distinct sedimentary patterns and the major influence of river sediment discharge in the formation of shelf deposits. The study used 98 surficial samples that were analyzed for grain size, composition and bulk density. Results revealed 3 distinct sectors: south - dominated by mud fraction with a recent deposition from riverine input until 30 m deep and from this depth bioclastic sands dominate; central north - sand mud dominated, been recognized as a bypass zone of resuspended sediment during high energy events; and north - relict sands with high carbonate content. The modern sedimentation processes along the Doce river continental shelf is dominated by distinct sedimentary regimes, showing a strong fluvial influence associated with wave/wind induced sediment dispersion and a carbonate regime along the outer shelf. These regimes seem to be controlled by the distance from the river mouth and bathymetric gradients.

  2. Biomarker distributions in different types of sedimentary organic matter isolated from the same sample: Implications for biomarker correlations

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, K.B.

    1994-06-01

    The observation of qualitatively and quantitatively distinct biomarker distributions in the pyrolysates of Type II and Type III organic matter isolated from the same sample is reported. This demonstrates the clear need for a greater understanding of the relationship between biomarker distributions present in the different components of sedimentary organic matter, and those observed in liquid products generated by maturation. The data imply that it is possible that the biomarker distributions observed in petroleums derived from inhomogeneous source rocks may be disproportionately derived from the various organic components of the sediment. This may result in spurious conclusions concerning oil/source relationships and other geochemical parameters, which suggests that further investigations of these phenomena is well merited.

  3. Cyclicity recorded in the provenance sandstones in the sedimentary in fill of the Cameros basin (N. Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Acebron, L.; Arribas, J.; Omodeo-Sale, S.; Arribas, E.; Le Pera, E.; Mas, R.; Lopez-Elorza, M.; Fernandez-Diaz, P. R.

    2013-06-01

    The intra plate Cameros rift basin in the north of Spain was formed came into being between the Tithonian and the Early Albian and contains 9 000 m of mostly continental sediments. This basin is a good example of cyclicity of different depositional sequences (DSs) in sedimentary environments, which show clear repetition in their sandstone composition (petrofacies) and diagenetic patterns. The DSs are arranged in two mega sequences (MSs) separated by a tectonic unconformity. A similar vertical sandstone compositional evolution, subdivided into two stages that repeat cyclically, has been recognised in both MSs: the first comprises quartzo-sedimentolithic petrofacies and the second is made up of several quartzo-feldspathic petrofacies. This was caused by a progression from the recycling of the pre-rift sedimentary cover to the erosion of the mainly plutonic and metamorphic crystalline basement. These changes in the erosion of the different source areas were conditioned by the tectonics of the basin. Furthermore, the original sandstone framework composition conditioned the diagenetic pattern of the two stages: quartzo-sedimentolithic sandstones containing large amounts of very pervasive carbonate cement that reduce their original porosity considerably, and quartzo-feldspathic petrofacies with a rigid framework that maintained the original pores during burial diagenesis. This compositional and diagenetic pattern is probably applicable to other non-volcanic rifted basins, depending upon the original amount of carbonate rock fragments present. (Author)

  4. Evaluation of magma mixing in the subvolcanic rocks of Ghansura Felsic Dome of Chotanagpur Granite Gneiss Complex, eastern India

    Science.gov (United States)

    Gogoi, Bibhuti; Saikia, Ashima; Ahmad, Mansoor; Ahmad, Talat

    2017-10-01

    The subvolcanic rocks exposed in the Ghansura Felsic Dome (GFD) of the Bathani volcano-sedimentary sequence at the northern fringe of the Rajgir fold belt in the Proterozoic Chotanagpur Granite Gneiss Complex preserves evidence of magma mixing and mingling in mafic (dolerite), felsic (microgranite) and intermediate (hybrid) rocks. Structures like crenulated margins of mafic enclaves, felsic microgranular enclaves and ocelli with reaction surfaces in mafic rocks, hybrid zones at mafic-felsic contacts, back-veining and mafic flows in the granitic host imply magma mingling phenomena. Textural features like quartz and titanite ocelli, acicular apatite, rapakivi and anti-rapakivi feldspar intergrowths, oscillatory zoned plagioclase, plagioclase with resorbed core and intact rim, resorbed crystals, mafic clots and mineral transporting veins are interpreted as evidence of magma mixing. Three distinct hybridized rocks have formed due to varied interactions of the intruding mafic magma with the felsic host, which include porphyritic diorite, mingled rocks and intermediate rocks containing felsic ocelli. Geochemical signatures confirm that the hybrid rocks present in the study area are mixing products formed due to the interaction of mafic and felsic magmas. Physical parameters like temperature, viscosity, glass transition temperature and fragility calculated for different rock types have been used to model the relative contributions of mafic and felsic end-member magmas in forming the porphyritic diorite. From textural and geochemical investigations it appears that the GFD was a partly solidified magma chamber when mafic magma intruded it leading to the formation of a variety of hybrid rock types.

  5. Changes of scaling relationships in an evolving population: The example of "sedimentary" stylolites

    Science.gov (United States)

    Peacock, D. C. P.; Korneva, I.; Nixon, C. W.; Rotevatn, A.

    2017-03-01

    Bed-parallel (;sedimentary;) stylolites are used as an example of a population that evolves by the addition of new components, their growth and their merger. It is shown that this style of growth controls the changes in the scaling relationships of the population. Stylolites tend to evolve in carbonate rocks through time, for example by compaction during progressive burial. The evolution of a population of stylolites, and their likely effects on porosity, are demonstrated using simple numerical models. Starting with a power-law distribution, the adding of new stylolites, the increase in their amplitudes and their merger decrease the slope of magnitude versus cumulative frequency of the population. The population changes to a non-power-law distribution as smaller stylolites merge to form larger stylolites. The results suggest that other populations can be forward- or backward-modelled, such as fault lengths, which also evolve by the addition of components, their growth and merger. Consideration of the ways in which populations change improves understanding of scaling relationships and vice versa, and would assist in the management of geofluid reservoirs.

  6. Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?

    Science.gov (United States)

    Emsbo, Poul; McLaughlin, Patrick I.; Breit, George N.; du Bray, Edward A.; Koenig, Alan E.

    2015-01-01

    The critical role of rare earth elements (REEs), particularly heavy REEs (HREEs), in high-tech industries has created a surge in demand that is quickly outstripping known global supply and has triggered a worldwide scramble to discover new sources. The chemical analysis of 23 sedimentary phosphate deposits (phosphorites) in the United States demonstrates that they are significantly enriched in REEs. Leaching experiments using dilute H2SO4 and HCl, extracted nearly 100% of their total REE content and show that the extraction of REEs from phosphorites is not subject to the many technological and environmental challenges that vex the exploitation of many identified REE deposits. Our data suggest that phosphate rock currently mined in the United States has the potential to produce a significant proportion of the world's REE demand as a byproduct. Importantly, the size and concentration of HREEs in some unmined phosphorites dwarf the world's richest REE deposits. Secular variation in phosphate REE contents identifies geologic time periods favorable for the formation of currently unrecognized high-REE phosphates. The extraordinary endowment, combined with the ease of REE extraction, indicates that such phosphorites might be considered as a primary source of REEs with the potential to resolve the global REE (particularly for HREE) supply shortage.

  7. The southern Svalbard Margin sedimentary system: preliminary results from EGLACOM cruise 2008

    Science.gov (United States)

    Melis, Romana; Lucchi, Renata G.; Giorgetti, Giovanna; Persico, Davide; Ángeles Bárcena, Maria; Caburlotto, Andrea; Macrı, Patrizia; Villa, Giuliana; Sagnotti, Leonardo; Rebesco, Michele

    2010-05-01

    The Storfjorden sedimentary system (South-western Svalbard margin) was investigated during the EGLACOM cruise between 8th July and 4th August 2008 on board R/V OGS-Explora. EGLACOM (Evolution of a GLacial Arctic COntinental Margin: the southern Svalbard ice stream-dominated sedimentary system) project is the Italian contribution to the International Polar Year (IPY) Activity 367 (Neogene ice streams and sedimentary processes on high-latitude continental margins - NICE STREAMS) in combination with the IPY-Spanish SVAIS project. Four EGLACOM sediment cores were collected from the slope and shelf areas and were scanned for radiographs and multi-sensor core logger for physical properties. Sediment samples were collected every 10 cm, and analyzed for textural and compositional characteristics including the biogenic components. Paleomagnetic and rock-magnetic investigations were carried out at high-resolution along the core's length. Both data sets contributed to develop a high-resolution age models in combination with the palaeostratigraphy (using foraminifera, diatoms and nannoplankton) and AMS dating. On the upper slope, coarser-grained sediments containing abundant pebbles (IRD-rich facies), overlain a sequence of laminated mud interbedded with silt layers (laminated facies), having scarce, badly preserved and often reworked biogenic fraction. On the lower slope, the uppermost sequence is formed by fine-grained bioturbated sediments with abundant planktonic and benthic foraminifera reflecting open-ocean conditions similar to present days. The dominance of the benthic foraminifera Cibicidoides wuellerstorfi indicates well oxygenated bottom waters and the calcareous nannofossil' assemblage indicates this facies deposited within the Emiliania huxleyi Acme Zone. The bioturbated facies overlay an interval of crudely laminated mud containing a peak of diatoms and sponge spiculae abundance that corresponds to a decrease in foraminifers content. Here the nannofossil

  8. From stones to rocks

    Science.gov (United States)

    Mortier, Marie-Astrid; Jean-Leroux, Kathleen; Cirio, Raymond

    2013-04-01

    With the Aquila earthquake in 2009, earthquake prediction is more and more necessary nowadays, and people are waiting for even more accurate data. Earthquake accuracy has increased in recent times mainly thanks to the understanding of how oceanic expansion works and significant development of numerical seismic prediction models. Despite the improvements, the location and the magnitude can't be as accurate as citizen and authorities would like. The basis of anticipating earthquakes requires the understanding of: - The composition of the earth, - The structure of the earth, - The relations and movements between the different parts of the surface of the earth. In order to answer these questions, the Alps are an interesting field for students. This study combines natural curiosity about understanding the predictable part of natural hazard in geology and scientific skills on site: observing and drawing landscape, choosing and reading a representative core drilling, replacing the facts chronologically and considering the age, the length of time and the strength needed. This experience requires students to have an approach of time and space radically different than the one they can consider in a classroom. It also limits their imagination, in a positive way, because they realize that prediction is based on real data and some of former theories have become present paradigms thanks to geologists. On each location the analyzed data include landscape, core drilling and the relation established between them by students. The data is used by the students to understand the meaning, so that the history of the formation of the rocks tells by the rocks can be explained. Until this year, the CBGA's perspective regarding the study of the Alps ground allowed students to build the story of the creation and disappearance of the ocean, which was a concept required by French educational authorities. But not long ago, the authorities changed their scientific expectations. To meet the

  9. Sm-Nd isotopic dating of Proterozoic clay material: An example from the Francevillian sedimentary series, Gabon

    Science.gov (United States)

    Bros, R.; Stille, P.; Gauthier-Lafaye, F.; Weber, F.; Clauer, N.

    1992-09-01

    Clay fractions of black shale samples from the Francevillian sedimentary series in Gabon. They yielded identical Sm-Nd isochron ages of2099 ± 115 Ma and2036 ± 79 Ma, with initialδ Nd values of-6.5 ± 2.0 and-9.3 ± 1.5, respectively. These ages define multi-episode illitization during early diagenesis, as suggested by the differentSm/Nd ratios of the clay fractions. The Sm-Nd isotope data of the kerogen source rock (up to 13% organic carbon) plot between the two isochrons but close to the clay fractions, suggesting that this organic matter reached Nd isotopic equilibrium with respect to the clay minerals and the diagenetic fluids. Analyses of fracture-filling bitumen showed that it had very elevated 143Nd/ 144Nd and 147Sm/ 144Nd ratios. These values are higher than the most elevated values of the leachates but plot on the extension of the two isochrons. This indicates that the bitumen reached Nd isotopic equilibrium with the kerogen source rock from which it was expelled and the authigenic clay minerals. Secondary migration and chemical evolution of the bitumen appear to have caused the fractionation between Sm and Nd with an attendant increase in theSm/Nd ratio. The results suggest that the Sm-Nd isotope method has potential for both dating diagenetically related illitization using leachate-residue pairs of small size clay fractions and reconstructing geochemical processes during diagenesis in oil-producing sedimentary basins.

  10. Combination of Slag, Limestone and Sedimentary Apatite in Columns for Phosphorus Removal from Sludge Fish Farm Effluents

    Directory of Open Access Journals (Sweden)

    Florent Chazarenc

    2010-08-01

    Full Text Available Laboratory scale studies have repeatedly reported high P-retention in slag, a by-product of the steel manufacturing industry. Thus, it has emerged as a potential material to increase P-removal from constructed wetlands (CWs. However, several limitations were highlighted by field experiments, including the high pH of treated water and clogging. We hypothesized that the addition of sedimentary rocks to slag would preserve P-removal properties while reducing the pH of treated water. Four 2.5 L-columns were filled with 100% apatite (column A; a 50% weight each mixture of limestone with apatite (column B; 10% steel slag located at the inlet, plus 45% limestone mixed with 45% apatite (column C; and a mixture of steel slag (10%, limestone (45% apatite (45% (column D. A synthetic effluent (26 mg P/L and a reconstituted sludge fish farm effluent containing 97 mg/L total suspended solids (TSS, 220 mg/L chemical oxygen demand (COD and 23.5 mg P/L phosphorus (P were applied sequentially during 373 and 176 days, under saturated flow conditions and 12–24 hours hydraulic residence time (HRT, respectively. Treatment performance, P-removal, pH and calcium (Ca2+ were monitored. Results indicated that columns that contained 10% weight steel slag resulted in a higher P retention capacity than the columns without steel slag. The highest P removal was achieved in column C, containing a layer of slag in the inlet zone, 45% apatite and 45% limestone. Feeding the columns with a reconstituted fish farm effluent led to biofilm development, but this had little effect on the P-removal. A combination of slag and sedimentary rocks represents a promising filtration material that could be useful downstream of CWs to further increase P-removal.

  11. Identification of genes encoding hypothetical proteins in open-reading frame expressed sequence tags from mammalian stages of Trypanosoma cruzi.

    Science.gov (United States)

    Martins, C; Reis-Cunha, J L; Silva, M N; Pereira, E G; Pappas, G J; Bartholomeu, D C; Zingales, B

    2011-01-01

    Approximately 50% of the predicted protein-coding genes of the Trypanosoma cruzi CL Brener strain are annotated as hypothetical or conserved hypothetical proteins. To further characterize these genes, we generated 1161 open-reading frame expressed sequence tags (ORESTES) from the mammalian stages of the VL10 human strain. Sequence clustering resulted in 435 clusters, consisting of 339 singletons and 96 contigs. Significant matches to the T. cruzi predicted gene database were found for ~94% contigs and ~69% singletons. These included genes encoding surface proteins, known to be intensely expressed in the parasite mammalian stages and implicated in host cell invasion and/or immune evasion mechanisms. Among 151 contigs and singletons with similarity to predicted hypothetical protein-coding genes and conserved hypothetical protein-coding genes, 83% showed no match with T. cruzi EST and/or proteome databases. These ORESTES are the first experimental evidence that the corresponding genes are in fact transcribed. Sequences with no significant match were searched against several T. cruzi and National Center for Biotechnology Information non-redundant sequence databases. The ORESTES analysis indicated that 124 predicted conserved hypothetical protein-coding genes and 27 predicted hypothetical protein-coding genes annotated in the CL Brener genome are transcribed in the VL10 mammalian stages. Six ORESTES annotated as hypothetical protein-coding genes showing no match to EST and/or proteome databases were confirmed by Northern blot in VL10. The generation of this set of ORESTES complements the T. cruzi genome annotation and suggests new stage-regulated genes encoding hypothetical proteins.

  12. Women's Behavioral Responses to the Threat of a Hypothetical Date Rape Stimulus: A Qualitative Analysis.

    Science.gov (United States)

    Anderson, RaeAnn E; Brouwer, Amanda M; Wendorf, Angela R; Cahill, Shawn P

    2016-05-01

    One in four college women experience sexual assault on campus; yet, campuses rarely provide the in-depth self-defense programs needed to reduce sexual assault risk. Further, little is known about the range of possible behaviors elicited by sexual assault threat stimuli besides assertion. To fill this gap, the aim of the current study was to explore qualitative themes in women's intended behavioral responses to a hypothetical sexual assault threat, date rape, by using a laboratory-controlled threat. College women (N = 139) were randomly assigned to one of four different levels of sexual assault threat presented via an audio-recorded vignette. Participants articulated how they would hypothetically respond to the experimentally assigned threat. Responses were blinded and analyzed using Consensual Qualitative Research methodology. Six major themes emerged: assertion, compliance/acceptance, conditional decision making, avoidance, expressions of discomfort, and allusion to future contact. Although almost all participants described assertion, a number of non-assertive responses were described that are not currently recognized in the literature. These non-assertive responses, including compliance/acceptance, conditional decision making, and avoidance, may represent unique behavioral response styles and likely reflect the complex psychological process of behavioral response to threat. The variety of themes found illustrates the great range of behavioral responses to threat. This broad range is not currently well represented or measured in the literature and better understanding of these responses can inform future interventions, advocacy efforts, and policies focused on sexual assault.

  13. Comparative analysis of chemical similarity methods for modular natural products with a hypothetical structure enumeration algorithm.

    Science.gov (United States)

    Skinnider, Michael A; Dejong, Chris A; Franczak, Brian C; McNicholas, Paul D; Magarvey, Nathan A

    2017-08-16

    Natural products represent a prominent source of pharmaceutically and industrially important agents. Calculating the chemical similarity of two molecules is a central task in cheminformatics, with applications at multiple stages of the drug discovery pipeline. Quantifying the similarity of natural products is a particularly important problem, as the biological activities of these molecules have been extensively optimized by natural selection. The large and structurally complex scaffolds of natural products distinguish their physical and chemical properties from those of synthetic compounds. However, no analysis of the performance of existing methods for molecular similarity calculation specific to natural products has been reported to date. Here, we present LEMONS, an algorithm for the enumeration of hypothetical modular natural product structures. We leverage this algorithm to conduct a comparative analysis of molecular similarity methods within the unique chemical space occupied by modular natural products using controlled synthetic data, and comprehensively investigate the impact of diverse biosynthetic parameters on similarity search. We additionally investigate a recently described algorithm for natural product retrobiosynthesis and alignment, and find that when rule-based retrobiosynthesis can be applied, this approach outperforms conventional two-dimensional fingerprints, suggesting it may represent a valuable approach for the targeted exploration of natural product chemical space and microbial genome mining. Our open-source algorithm is an extensible method of enumerating hypothetical natural product structures with diverse potential applications in bioinformatics.

  14. Hypothetical Case and Scenario Description for International Transportation of Spent Nuclear Fuel.

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Adam David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Osborn, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kalinina, Elena Arkadievna [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cohn, Brian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thomas, Maikael A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Parks, Mancel Jordan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Parks, Ethan Rutledge [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mohagheghi, Amir H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-12-01

    To support more rigorous analysis on global security issues at Sandia National Laboratories (SNL), there is a need to develop realistic data sets without using "real" data or identifying "real" vulnerabilities, hazards or geopolitically embarrassing shortcomings. In response, an interdisciplinary team led by subject matter experts in SNL's Center for Global Security and Cooperation (CGSC) developed a hypothetical case description. This hypothetical case description assigns various attributes related to international SNF transportation that are representative, illustrative and indicative of "real" characteristics of "real" countries. There is no intent to identify any particular country and any similarity with specific real-world events is purely coincidental. To support the goal of this report to provide a case description (and set of scenarios of concern) for international SNF transportation inclusive of as much "real-world" complexity as possible -- without crossing over into politically sensitive or classified information -- this SAND report provides a subject matter expert-validated (and detailed) description of both technical and political influences on the international transportation of spent nuclear fuel. [PAGE INTENTIONALLY LEFT BLANK

  15. A flexible tool for calculating the consequences of a hypothetical nuclear accident

    Directory of Open Access Journals (Sweden)

    Eugenio Tabet

    2011-01-01

    Full Text Available The paper presents a parametric model, implemented on a personal computer, for calculating contamination and doses following a hypothetical nuclear accident. The model is embedded in the high level environment of Mathematica and uses the Gaussian solution for the plume structure at short and medium distances and a wedge-like behaviour for long distances calculation. Along with the usual effects, like the influence of a local wet ground deposition or the corrections due to build-up, the model deals also with other aspects, such as the long distance behaviour of the plume, by taking into account random wind direction variations. A rather sophisticated approach is used, in particular, when evaluating food contamination and doses, allowing also for consideration of a possible ban of food consumption. Several tens of functions are on hand of the user who can take full advantage of the very flexible tools introduced in the recent version 7 of Mathematica. Some examples of the power of the tool are shown with reference to the radiological consequences of an hypothetical accidental release in a EPR reactor.

  16. OPPORTUNITY COSTS OF REWARD DELAYS AND THE DISCOUNTING OF HYPOTHETICAL MONEY AND CIGARETTES

    Science.gov (United States)

    Johnson, Patrick S.; Herrmann, Evan S.; Johnson, Matthew W.

    2015-01-01

    Humans are reported to discount delayed rewards at lower rates than nonhumans. However, nonhumans are studied in tasks that restrict reinforcement during delays, whereas humans are typically studied in tasks that do not restrict reinforcement during delays. In nonhuman tasks, the opportunity cost of restricted reinforcement during delays may increase delay discounting rates. The present within-subjects study used online crowdsourcing (Amazon Mechanical Turk, or MTurk) to assess the discounting of hypothetical delayed money (and cigarettes in smokers) under four hypothetical framing conditions differing in the availability of reinforcement during delays. At one extreme, participants were free to leave their computer without returning, and engage in any behavior during reward delays (modeling typical human tasks). At the opposite extreme, participants were required to stay at their computer and engage in little other behavior during reward delays (modeling typical nonhuman tasks). Discounting rates increased as an orderly function of opportunity cost. Results also indicated predominantly hyperbolic discounting, the “magnitude effect,” steeper discounting of cigarettes than money, and positive correlations between discounting rates of these commodities. This is the first study to test the effects of opportunity costs on discounting, and suggests that procedural differences may partially account for observed species differences in discounting. PMID:25388973

  17. Opportunity costs of reward delays and the discounting of hypothetical money and cigarettes.

    Science.gov (United States)

    Johnson, Patrick S; Herrmann, Evan S; Johnson, Matthew W

    2015-01-01

    Humans are reported to discount delayed rewards at lower rates than nonhumans. However, nonhumans are studied in tasks that restrict reinforcement during delays, whereas humans are typically studied in tasks that do not restrict reinforcement during delays. In nonhuman tasks, the opportunity cost of restricted reinforcement during delays may increase delay discounting rates. The present within-subjects study used online crowdsourcing (Amazon Mechanical Turk, or MTurk) to assess the discounting of hypothetical delayed money (and cigarettes in smokers) under four hypothetical framing conditions differing in the availability of reinforcement during delays. At one extreme, participants were free to leave their computer without returning, and engage in any behavior during reward delays (modeling typical human tasks). At the opposite extreme, participants were required to stay at their computer and engage in little other behavior during reward delays (modeling typical nonhuman tasks). Discounting rates increased as an orderly function of opportunity cost. Results also indicated predominantly hyperbolic discounting, the "magnitude effect," steeper discounting of cigarettes than money, and positive correlations between discounting rates of these commodities. This is the first study to test the effects of opportunity costs on discounting, and suggests that procedural differences may partially account for observed species differences in discounting. © Society for the Experimental Analysis of Behavior.

  18. Conceptualization of a hypothetical high-level nuclear waste repository site in unsaturated, fractured tuff

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, A.M.; Olague, N.E.; Gallegos, D.P. [Sandia National Labs., Albuquerque, NM (USA)

    1991-01-01

    Under the sponsorship of the US Nuclear Regulatory Commission (NRC), Sandia National Laboratories (SNL) is developing a performance assessment methodology for the analysis of long-term disposal and isolation of high-level nuclear wastes (HLW) in alternative geologic media. As part of this exercise, SNL created a conceptualization of ground-water flow and radionuclide transport in the far field of a hypothetical HLW repository site located in unsaturated, fractured tuff formations. This study provides a foundation for the development of conceptual mathematical, and numerical models to be used in this performance assessment methodology. This conceptualization is site specific in terms of geometry, the regional ground-water flow system, stratigraphy, and structure in that these are based on information from Yucca Mountain located on the Nevada Test Site. However, in terms of processes in unsaturated, fractured, porous media, the model is generic. This report also provides a review and evaluation of previously proposed conceptual models of unsaturated and saturated flow and solute transport. This report provides a qualitative description of a hypothetical HLW repository site in fractured tuff. However, evaluation of the current knowledge of flow and transport at Yucca Mountain does not yield a single conceptual model. Instead, multiple conceptual models are possible given the existing information.

  19. The effects of restaurant menu calorie labeling on hypothetical meal choices of females with disordered eating.

    Science.gov (United States)

    Haynos, Ann F; Roberto, Christina A

    2017-03-01

    Concerns have been raised that obesity public policy measures may have harmful effects on individuals with eating disorders. However, little research has investigated this topic. We examined the impact of a popular obesity public policy, menu calorie labeling, on hypothetical food choices of women with disordered eating. Seven hundred sixteen adult females completed an online survey in which they were randomly assigned to receive a restaurant menu with or without calorie information listed. Participants selected foods representative of a meal they would choose to consume and answered questions on restaurant ordering and menu labeling. Participants completed the Eating Disorder Examination Questionnaire (Fairburn & Beglin, ) to assess global eating pathology. Diagnoses of anorexia nervosa (AN), bulimia nervosa (BN), and binge-eating disorder (BED) were also derived from this measure. Generalized linear modeling examined the impact of menu label condition, disordered eating, and the menu label by disordered eating interaction on hypothetical food selection and related variables. When disordered eating was examined continuously, menu labeling did not differentially affect food selections of those with elevated disordered eating (p = .45). However, when examined by eating disorder diagnosis, participants with AN or BN ordered significantly fewer (p menu label versus no label condition. Menu labeling may decrease the calories ordered among individuals with AN or BN and increase calories ordered among individuals with BED. © 2017 Wiley Periodicals, Inc.

  20. Patient assessments of a hypothetical medical error: effects of health outcome, disclosure, and staff responsiveness.

    Science.gov (United States)

    Cleopas, A; Villaveces, A; Charvet, A; Bovier, P A; Kolly, V; Perneger, T V

    2006-04-01

    To assess whether patients' perceptions of a hypothetical medical error are influenced by staff responsiveness, disclosure of error, and health consequences of the error. Hypothetical scenario describing a medication error submitted by mail. Three factors were manipulated at random: rapid v slow staff responsiveness to error; disclosure v non-disclosure of the error; and occurrence of serious v minor health consequences. Patients discharged from hospital. Assessment of care described in the scenario as bad or very bad, rating of care as unsafe, and intent to not recommend the hospital. Of 1274 participants who evaluated the scenario, 71.4% rated health care as bad or very bad, 60.2% rated healthcare conditions as unsafe, and 25.5% stated that they would not recommend the hospital. Rating health care as bad or very bad was associated with slow reaction to error (odds ratio (OR) 2.8, 95% CI 2.1 to 3.6), non-disclosure of error (OR 2.0, 95% CI 1.5 to 2.6), and serious health consequences (OR 3.4, 95% CI 2.6 to 4.5). Similar associations were observed for rating healthcare conditions as unsafe and the intent to not recommend the hospital. Younger patients were more sensitive to non-disclosure than older patients. Former patients view medical errors less favorably when hospital staff react slowly, when the error is not disclosed to the patient, and when the patient suffers serious health consequences.

  1. Ab initio total energy study of brucite, diaspore and hypothetical hydrous wadsleyite

    Science.gov (United States)

    Winkler, B.; Milman, V.; Hennion, B.; Payne, M. C.; Lee, M.-H.; Lin, J. S.

    1995-10-01

    Ab initio total energy calculations based on the local density approximation (LDA) and the generalised gradient approximation (GGA) of density functional theory have been performed for brucite, Mg(OH)2, diaspore, AlOOH and hypothetical hydrous wadsleyite, Mg7Si4O14(OH)2. The use of a general gradient approximation (GGA) is essential to obtain a good agreement (≈ 1%) of the calculated lattice parameters to diffraction data. The calculated fractional coordinates of brucite and diaspore are in good agreement (≈ 1.5%) with experimental data. The angle of the non-linear hydrogen bond in diaspore is reproduced well, and the calculated Raman active OH stretching frequency in brucite is in very good agreement with spectroscopic data. There are no significant differences between the calculated fractional coordinates and the second derivative of the energy when GGA is used instead of standard LDA. It is concluded that the description of the static and the dynamic behavior of the OH groups in these hydroxides is very good. It is therefore inferred that the parameter free model is predictive and it has been used to evaluate a hypothetical structure of hydrous wadsleyite. The model reproduces the unusual Si-O bond length of 1.7 Å, observed in β-Mg2SiO4. It predicts an O-H distance of 0.97 Å, which is significantly shorter than the distance obtained from earlier model calculations.

  2. Evaluating the impacts of farmers' behaviors on a hypothetical agricultural water market based on double auction

    Science.gov (United States)

    Du, Erhu; Cai, Ximing; Brozović, Nicholas; Minsker, Barbara

    2017-05-01

    Agricultural water markets are considered effective instruments to mitigate the impacts of water scarcity and to increase crop production. However, previous studies have limited understanding of how farmers' behaviors affect the performance of water markets. This study develops an agent-based model to explicitly incorporate farmers' behaviors, namely irrigation behavior (represented by farmers' sensitivity to soil water deficit λ) and bidding behavior (represented by farmers' rent seeking μ and learning rate β), in a hypothetical water market based on a double auction. The model is applied to the Guadalupe River Basin in Texas to simulate a hypothetical agricultural water market under various hydrological conditions. It is found that the joint impacts of the behavioral parameters on the water market are strong and complex. In particular, among the three behavioral parameters, λ affects the water market potential and its impacts on the performance of the water market are significant under most scenarios. The impacts of μ or β on the performance of the water market depend on the other two parameters. The water market could significantly increase crop production only when the following conditions are satisfied: (1) λ is small and (2) μ is small and/or β is large. The first condition requires efficient irrigation scheduling, and the second requires well-developed water market institutions that provide incentives to bid true valuation of water permits.

  3. Underground Hydrosphere of the Sedimentary Basins as Naphtides-Generating System (on the Example of the South Caspian Basin

    Directory of Open Access Journals (Sweden)

    A.A. Feyzullayev

    2017-11-01

    Full Text Available The analysis of organic matter (OM content dissolved in the formation waters and waters of mud volcanoes (water dissolved organic matter – DOM of the oil and gas bearing South Caspian Basin and its distribution in stratigraphic and hypsometrical depth is given in the article. The stratigraphic interval of research covers the period from the Lower Pliocene to the Jurassic, and the depth interval: from 73 to 6043 m. In these intervals, the values ​​of the DOM in reservoir waters vary from 4.1 mg/l to 271.2 mg /l, averaging (by 219 analyzes 48.9 mg/l. A good correlation of the values ​​of DOM and OM in rocks has been established. In both cases, Paleogene and Jurassic rocks have the highest values. In the change of the DOM with depth, an increase in its values ​​from a depth of about 3.3 km is noted, which is possibly due to the onset of catagenetic transformation of OM into hydrocarbons in the rock-water system. The dependence of the DOM content on the mineralization of water has been established: its highest values ​​are characteristic for waters with mineralization not higher than 50 g/l. The waters of mud volcanoes are characterized by low levels of DOM and low mineralization, which is most likely due to their condensation nature. The conducted studies confirm the idea of ​​the DOM participation, along with the OM of rocks, in the processes of oil and gas generation. The process of OM transformation into oil and gas in aqueous solution should be taken into account in basin modeling and in estimating the predicted resources of hydrocarbons in the sedimentary basin.

  4. Constraints in the hot-dry-rock resources of the united states

    Science.gov (United States)

    Sass, John; Guffanti, Marianne; ,

    1993-01-01

    As with hydrothermal systems, the western U.S has higher HDR potential overall than the eastern U.S. because geothermal gradients on average are higher in the west. Nevertheless, some attractive exploration targets occur in the eastern U.S. The most favorable target in the eastern U.S. (defined here to include the Great Plains province) is one in which the heat flow from the basement rocks is higher than average, either due to heat generation from highly radioactive rocks or to a plume of hot water driven upwards from greater depths by convection, and where such basement rocks are blanketed by one or more kilometers of sedimentary material having a low thermal conductivity.

  5. ROCK TYPOLOGY IN CHOOSING SPRINGS. ANCIENT METHODS FOR DETERMINING WATER QUALITY IN THE PARMA REGION

    Directory of Open Access Journals (Sweden)

    Valentino Straser

    2011-12-01

    Full Text Available This study was a scientific validation of some ancient methods used for purifying water and selecting springs based on the nature of the soil and rocks. A historical and scientific analysis of the territory was made, with the aim of trying to identify ancient methods which might be retrieved and used again in a modern way for a comprehensive interpretation of the environment we live in. The investigation was led near Parma in the north of Italy, in mountainous and hilly areas which rise from rocky outcrops consisting of fragments of the ancient oceanic crust composed of argillaceous complexes, ultrabasic rocks from the ophiolite succession as well as flyschoid sedimentary rocks containing arenaceous, carboniferous and marly elements.

  6. Rock Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C. Lum

    2004-09-16

    The purpose of this model report is to document the Rock Properties Model version 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties model provides mean matrix and lithophysae porosity, and the cross-correlated mean bulk density as direct input to the ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021, REV 02 (BSC 2004 [DIRS 170042]). The constraints, caveats, and limitations associated with this model are discussed in Section 6.6 and 8.2. Model validation accomplished by corroboration with data not cited as direct input is discussed in Section 7. The revision of this model report was performed as part of activities being conducted under the ''Technical Work Plan for: The Integrated Site Model, Revision 05'' (BSC 2004 [DIRS 169635]). The purpose of this revision is to bring the report up to current procedural requirements and address the Regulatory Integration Team evaluation comments. The work plan describes the scope, objectives, tasks, methodology, and procedures for this process.

  7. A smart rock

    Science.gov (United States)

    Pressel, Phil

    2014-12-01

    This project was to design and build a protective weapon for a group of associations that believed in aliens and UFO's. They collected enough contributions from societies and individuals to be able to sponsor and totally fund the design, fabrication and testing of this equipment. The location of this facility is classified. It also eventually was redesigned by the Quartus Engineering Company for use at a major amusement park as a "shoot at targets facility." The challenge of this project was to design a "smart rock," namely an infrared bullet (the size of a gallon can of paint) that could be shot from the ground to intercept a UFO or any incoming suspicious item heading towards the earth. Some of the challenges to design this weapon were to feed cryogenic helium at 5 degrees Kelvin from an inair environment through a unique rotary coupling and air-vacuum seal while spinning the bullet at 1500 rpm and maintain its dynamic stability (wobble) about its spin axis to less than 10 micro-radians (2 arc seconds) while it operated in a vacuum. Precision optics monitored the dynamic motion of the "smart rock."

  8. Rock critics as 'Mouldy Modernists'

    Directory of Open Access Journals (Sweden)

    Becky Shepherd

    2011-08-01

    Full Text Available Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly, the maintenance of the rock canon within contemporary popular culture. The article concludes by suggesting that while contemporary rock criticism is predominately characterised by nostalgia, this nostalgia is not simply a passive romanticism of the past. Rather, this nostalgia fuels a process of active recontextualisation within contemporary popular culture.

  9. Diffusive transport and reaction in clay rocks: A storage (nuclear waste, CO2, H2), energy (shale gas) and water quality issue

    Science.gov (United States)

    Charlet, Laurent; Alt-Epping, Peter; Wersin, Paul; Gilbert, Benjamin

    2017-08-01

    Clay rocks are low permeability sedimentary formations that provide records of Earth history, influence the quality of water resources, and that are increasingly used for the extraction or storage of energy resources and the sequestration of waste materials. Informed use of clay rock formations to achieve low-carbon or carbon-free energy goals requires the ability to predict the rates of diffusive transport processes for chemically diverse dissolved and gaseous species over periods up to thousands of years. We survey the composition, properties and uses of clay rock and summarize fundamental science challenges in developing confident conceptual and quantitative gas and solute transport models.

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

    Science.gov (United States)

    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

  11. Study of Sedimentary Outcrop of Semanggol Formation with the Correlation of Geology, Geotechnical and Geophysics Technique

    Science.gov (United States)

    Nordiana, A. N.; Nordiana, M. M.; Jia, Teoh Ying; Hisham, Hazrul; Sulaiman, Nabila; Maslinda, Umi; Taqiuddin, Z. M.; Nur Amalina, M. K. A.; Afiq Saharudin, Muhamad

    2017-04-01

    The study location was at Bukit Kukus, Kuala Ketil, Kedah, Malaysia where the geological outcrop of this Semanggol Formation comprises of chert, mudstone, and volcanic tuff. The study was conducted using two geophysical methods, which are 2-D Resistivity and Ground Penetrating Radar (GPR). The objectives of the study are to correlate both of the geophysical methods through the value of conductivity and to identify the physical properties of rocks through the value of porosity and permeability. The data acquisition for both methods was conducted on the same line. For 2-D Resistivity method, the length of the line is 60 m with 1.5 m electrode spacing and the array used was Wenner-Schlumberger. For GPR method, the survey line was on top of the resistivity line, and the frequency of the antenna used is 250 MHz. A good correlation exists between both of the GPR signature and contour maps for resistivity from the surfer 10 software with the outcrop feature. Conductivity value from both GPR and Resistivity method was compared and the range value of conductivity obtained from GPR method almost equivalent with Resistivity method based on derivation and calculation for the sedimentary rocks, which are 0.037 to 0.574 miliSiemens per metre (mS/m) for chert and 0.186 to 10.142 miliSiemens per metre (mS/m) for mudstone. Two types of rock samples were taken, and several geotechnical tests were conducted, but only the value of permeability, K and porosity, ɸ of chert can be calculated, which are 1.95E-22 m2 (original condition) and 2.27E-22 m2 (dry condition) and 3 percent respectively as the sample of mudstone was damaged. The parameter of the 2-D resistivity method derived from Archie’s law was used to calculate the porosity, ɸf value using the Formation Factor equation. The range values of porosity, ɸf for chert mostly in the range of 5 to 25 percent, which is 6.26 to 13.36 percent but slightly out of range for mudstone, which is 14.12 to 36.02 percent.

  12. Early veins as evidence of detachment in the Lower Palaeozoic rocks of the Welsh Basin

    Science.gov (United States)

    Fitches, W. R.; Cave, R.; Craig, J.; Maltman, A. J.

    A suite of small-scale structures, mostly represented by veins, is widely developed in the Lower Palaeozoic elastic sedimentary rocks of the Welsh Basin. The structures were produced after considerable dewatering and diagenesis had taken place, but before the host rocks were folded and cleaved by the regional deformation. Bedding-parallel veins, the most common of the structures, are attributed to hydraulic jacking and mineralization by overpressured pore-fluid, probably at burial depths of several hundred metres or more. The various burial processes, including the production of the veins, are regarded as being diachronous, in effect propagating up through the sediment pile as sedimentation and burial progressed. The bedding-parallel veins are considered to represent inclined detachment surfaces, sole planes down which rock masses slid due to gravity. These surfaces were initiated in rocks originally inclined from the horizontal for sedimentological reasons or in horizontal host rocks which were later tilted by tectonic processes. Other structures in the suite were produced as a consequence of the downslope movement, for example by compression in the toe regions of the glide-sheet and by extension at the trailing edges. Slip directions, recorded by striations on the bedding-parallel veins, were mainly WNW-ESE in W Wales and N-S in NE Wales. It is anticipated that these structures will be found to be widespread in other sedimentary basins. That they have escaped attention elsewhere is probably because individual structures are small and seemingly insignificant whilst in deformed rocks they may have been attributed to folding or faulting.

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