Sample records for cambrian sandstones burial

  1. Ferroan dolomite cement in Cambrian sandstones: burial history and hydrocarbon generation of the Baltic sedimentary basin

    DEFF Research Database (Denmark)

    Sliaupa, S.; Cyziene, J.; Molenaar, Nicolaas


    . The burial history modelling points to development of most of the dolomite cement during rapid Silurian-Devonian subsidence and Carboniferous-early Permian uplift. A wide range of precipitation temperatures indicate that temperature was not a major factor in triggering the carbonate cementation. Dolomite...

  2. Provenance shift in Cambrian mid-Baltica: detrital zircon chronology of Ediacaran–Cambrian sandstones in Estonia

    Directory of Open Access Journals (Sweden)

    Yukio Isozaki


    Full Text Available In order to clarify the tectono-sedimentary history of Paleozoic Baltica, age spectra of detrital zircon grains from the Ediacaran (Kotlin Regional Stage and Lower Cambrian sandstones (lowermost Lontova and Lükati formations in western Estonia in central Baltica were analyzed by LA-ICPMS. The abundant occurrence of Archean to Mesoproterozoic (2800–1000 Ma zircon grains was confirmed in all samples. The new data provided the following information on the provenance of siliciclastic material as well as a major change in the sedimentary regime of the Paleo-Baltic basin during the Early Cambrian: (1 the Ediacaran–Lower Cambrian Paleo-Baltic basin received abundant terrigenous clastics from the core of Baltica underlain by the Archean–Mesoproterozoic crystalline crust, (2 the exposed surface area of the 1600 Ma Rapakivi granites apparently was more extensive during the Ediacaran–Early Cambrian than at present, (3 a major re-organization of the basin geometry occurred in the middle Early Cambrian (ca 530–515 Ma in central Baltica, inducing a change in the sediment supply system, (4 in contrast to the total absence of Neoproterozoic detrital zircon grains before the middle Early Cambrian, their sudden appearance at this time, together with consistent occurrence at least until the mid-Devonian, suggests a significant uplift event located in southeast Baltica and/or in a more easterly land domain (e.g., in Sarmatia, (5 possible sources for the Neoproterozoic zircon grains include the peripheral mobile belts with pan-African signatures around Baltica, e.g., the so-called Gondwanan fragments along the Tornquist margin to the southwest and the Timanian belt along the northeastern margin.

  3. Halomonas sulfidaeris-dominated microbial community inhabits a 1.8 km-deep subsurface Cambrian Sandstone reservoir. (United States)

    Dong, Yiran; Kumar, Charu Gupta; Chia, Nicholas; Kim, Pan-Jun; Miller, Philip A; Price, Nathan D; Cann, Isaac K O; Flynn, Theodore M; Sanford, Robert A; Krapac, Ivan G; Locke, Randall A; Hong, Pei-Ying; Tamaki, Hideyuki; Liu, Wen-Tso; Mackie, Roderick I; Hernandez, Alvaro G; Wright, Chris L; Mikel, Mark A; Walker, Jared L; Sivaguru, Mayandi; Fried, Glenn; Yannarell, Anthony C; Fouke, Bruce W


    A low-diversity microbial community, dominated by the γ-proteobacterium Halomonas sulfidaeris, was detected in samples of warm saline formation porewater collected from the Cambrian Mt. Simon Sandstone in the Illinois Basin of the North American Midcontinent (1.8 km/5872 ft burial depth, 50°C, pH 8, 181 bars pressure). These highly porous and permeable quartz arenite sandstones are directly analogous to reservoirs around the world targeted for large-scale hydrocarbon extraction, as well as subsurface gas and carbon storage. A new downhole low-contamination subsurface sampling probe was used to collect in situ formation water samples for microbial environmental metagenomic analyses. Multiple lines of evidence suggest that this H. sulfidaeris-dominated subsurface microbial community is indigenous and not derived from drilling mud microbial contamination. Data to support this includes V1-V3 pyrosequencing of formation water and drilling mud, as well as comparison with previously published microbial analyses of drilling muds in other sites. Metabolic pathway reconstruction, constrained by the geology, geochemistry and present-day environmental conditions of the Mt. Simon Sandstone, implies that H. sulfidaeris-dominated subsurface microbial community may utilize iron and nitrogen metabolisms and extensively recycle indigenous nutrients and substrates. The presence of aromatic compound metabolic pathways suggests this microbial community can readily adapt to and survive subsurface hydrocarbon migration. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Isotopically zoned carbonate cements in Early Paleozoic sandstones of the Illinois Basin: δ18O and δ13C records of burial and fluid flow (United States)

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


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

  5. Geochemical interpretation of the Precambrian basement and overlying Cambrian sandstone on Bornholm, Denmark: Implications for the weathering history (United States)

    Zhou, Lingli; Friis, Henrik; Yang, Tian; Nielsen, Arne Thorshøj


    A geochemical study of the Precambrian basement granites from the Borggård borehole on Bornholm, Denmark, suggests that the granites were moderately weathered (Chemical Index of Alteration-CIA = 66-71) during subaerial exposure in a humid climate. The microcline is well preserved, whereas plagioclase was thoroughly altered to clay minerals (Plagioclase Index of Alteration-PIA = 93-99) which is likely due to its original Ca-rich composition. The primary Fe-Ti accessory minerals were oxidized to hematite and anatase. Evidence from REE distribution patterns and immobile element ratios, e.g. Zr/Hf and Nb/Ta, between the weathered basement granite from the Borggård borehole and regional granitoids on Bornholm, constrains the Svaneke Granite as the original basement lithology. A tau (τ) mass transport model (assuming immobile Ti) was applied to quantify the mass transfer during weathering of the basement granite. The results show a depletion of major elements in the following order: Na > Ca > Mg > Si; Al and Ti are immobile and stay constant; K shows sample dependent enrichment or depletion; Fe is slightly enriched. The Cambrian sandstone overlying the basement in the Borggård borehole, assigned to the Gadeby Member of the Nexø Formation, is feldspathic litharenite-litharenite in composition. Provenance indicators including (Gd/Yb)N, Zr/Hf and Nb/Ta ratios and petrological features indicate that source material was derived from both weathered and fresh basement granite of intermediate composition. The Gadeby Member equivalents in Germany, the basal lower Cambrian Adlergrund Konglomerat Member (AKM) in the offshore G-14 well north of Rügen, and the approximately coeval Lubmin Sandstein Formation (LSF) from the Loissin-1 borehole, mainland Germany, must have been sourced from a basement with compositions comparable to the intermediate group of the regional granitoids on Bornholm. The source materials for the AKM (CIA = 71-72, PIA = 94-96), the Gadeby Member in the

  6. Depositional and diagenetic variability within the Cambrian Mount Simon Sandstone: Implications for carbon dioxide sequestration (United States)

    Bowen, B.B.; Ochoa, R.I.; Wilkens, N.D.; Brophy, J.; Lovell, T.R.; Fischietto, N.; Medina, C.R.; Rupp, J.A.


    The Cambrian Mount Simon Sandstone is the major target reservoir for ongoing geologic carbon dioxide (CO2) sequestration demonstrations throughout the midwest United States. The potential CO2 reservoir capacity, reactivity, and ultimate fate of injected CO2 depend on textural and compositional properties determined by depositional and diagenetic histories that vary vertically and laterally across the formation. Effective and efficient prediction and use of the available pore space requires detailed knowledge of the depositional and diagenetic textures and mineralogy, how these variables control the petrophysical character of the reservoir, and how they vary spatially. Here, we summarize the reservoir characteristics of the Mount Simon Sandstone based on examination of geophysical logs, cores, cuttings, and analysis of more than 150 thin sections. These samples represent different parts of the formation and depth ranges of more than 9000 ft (>2743 m) across the Illinois Basin and surrounding areas. This work demonstrates that overall reservoir quality and, specifically, porosity do not exhibit a simple relationship with depth, but vary both laterally and with depth because of changes in the primary depositional facies, framework composition (i.e., feldspar concentration), and diverse diagenetic modifications. Diagenetic processes that have been significant in modifying the reservoir include formation of iron oxide grain coatings, chemical compaction, feldspar precipitation and dissolution, multiple generations of quartz overgrowth cementation, clay mineral precipitation, and iron oxide cementation. These variables provide important inputs for calculating CO2 capacity potential, modeling reactivity, and are also an important baseline for comparisons after CO2 injection. Copyright ??2011. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  7. The influence of climate on early and burial diagenesis of Triassic and Jurassic sandstones from the Norwegian – Danish Basin

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kjøller, Claus


    Climate changes preserved in sandstones are documented by comparing the sediment composition and early diagenetic changes in sandstones deposited during arid to semi-arid conditions, the Skagerrak Formation, with sandstones of the Gassum Formation deposited in a humid well-vegetated environment...... to the Gassum Formation, which was characterized by quartz and more stable heavy minerals. The arid to semi-arid climate led to early oxidising conditions under which abundant iron-oxide/hydroxide coatings formed, while the evaporative processes occasionally resulted in caliche and gypsum precipitation. Under...... changes occurring during deeper burial, so dolomite preferentially formed in the sandstones deposited in an arid environment while ankerite characterises sandstones deposited under humid conditions. In addition to climate induced burial diagenetic changes, there are also temperature dependent phases...

  8. Lack of inhibiting effect of oil emplacement on quartz cementation: Evidence from Cambrian reservoir sandstones, Paleozoic Baltic Basin

    DEFF Research Database (Denmark)

    Molenaar, Nicolaas; Cyziene, Jolanta; Sliaupa, Saulius


    , including sandstone architecture, i.e., distribution of shales within the sandstone bodies, and sandstone thickness. Heterogeneity is inherent to sandstone architecture and to the fact that silica for quartz cementation is derived from heterogeneously distributed local pressure solution. Models predicting...

  9. Elasto-Plastic Constitutive Behavior in Three Lithofacies of the Cambrian Mt. Simon Sandstone, Illinois Basin, USA (United States)

    Dewers, T.; Newell, P.; Broome, S. T.; Heath, J. E.; Bauer, S. J.


    The Mt. Simon Formation, a basal Cambrian sandstone underlying the Illinois Basin in the Central US, is a target for underground storage and waste injection which require an assessment of geomechanical behavior. The range of depositional environments, from braided streams and minor eolean features in the lower Mt Simon, to tidally-influenced near- and on-shore sands in the upper Mt. Simon, yield a heterogeneous formation with a range in porosity, permeability, and mechanical properties. We examine the experimental deformational behavior of three distinct Mt. Simon lithofacies via axisymmetric compressional testing. Initial yielding is confirmed with acoustic emissions in many of the tests and failure envelopes are determined for each lithofacies. The evolution of (assumed) isotropic elastic moduli are examined during testing by use of unload-reload cycles, which permit the separation of total measured strains into elastic and plastic (permanent) strains. The upper Mt Simon samples deform largely elastically at stresses encountered in the Illinois Basin, with very little modulus degradation. The lower Mt. Simon facies are weaker and deform plastically, with varying amounts of modulus degradation. Results are interpreted via petrographic observation of textural contrasts. This range in constitutive response is captured up to failure with a phenomenological elasto-plasticity model. Essential aspects to describe observed behavior used in the model include non-associative plasticity, stress-invariant dependent failure, an elliptical cap surface capturing shear effects on pore collapse, kinematic and isotropic hardening, nonlinear elasticity and elastic-plastic coupling, among other features. Static moduli derived from laboratory tests are compared to dynamic moduli from wellbore log response which can allow experimental results and model to be extrapolated to Mt. Simon occurrences across the basin. This work was funded in part by the Center for Frontiers of Subsurface

  10. Geochemical and Mineralogical Evaluation of CO2-Brine-Rock Experiments: Characterizing Porosity and Permeability Variations in the Cambrian Mount Simon Sandstone (United States)

    Gonzalez, A. B.; Bowen, B. B.


    The Cambrian Mount Simon Sandstone has been targeted as a major reservoir for carbon dioxide storage in the Illinois Basin. The Mount Simon Sandstone's geologic setting, mature quartz to arkosic composition, reservoir thickness, and overlying Eau Claire Formation seal make it an attractive candidate for long-term storage potential of carbon dioxide. Injection of carbon dioxide has been shown to cause a range of chemical alterations that causes dissolution of existing minerals and precipitation of secondary phases that can alter the porosity and permeability of the reservoir. This study focuses on using detailed microscopic analysis of two compositionally and texturally different Mount Simon Sandstone samples from the Illinois Basin that were experimentally exposed to CO2-rich brines for 6 months at the NETL in collaboration with the Indiana Geological Survey. Our objective was to examine the experimental samples to determine how post-experiment mineralogical and geochemical alterations relate to porosity and permeability variations. Gazzi-Dickinson point counting of Vermillion County samples adjacent to experimental sample depths (5805 ft) show that the sample contains an average of 78% quartz, 15% feldspar, 2% lithics, and 5% porosity. Point count data of Knox County samples from 8642.5, 8542, and 8642.2 show the experimental sample has an average of 70% quartz, 22% feldspar, 4% lithics, and 3.9% porosity. Both samples were submerged in carbon dioxide-saturated brine synthesized to match the measured geochemistry of Mount Simon Sandstone pore water for six months at 24MPa and 90 degrees to replicate sequestration conditions. The results of the experiment for the Vermillion County sample revealed a significant decrease in permeability and porosity. However the Knox County sample had a minor increase in permeability and porosity. Geochemical analyses (IC, ICP-MS, and ICP-OES) of brine geochemistry before and after the experiment show a decrease in pH and an increase

  11. Burial diagenetic processes of clay mineral and non-clay mineral, quartz cementation and dissolution in sandstones and mudstones of the Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan Byskov

    grains (diatoms, radiolaria, sponge spicules), silica released from the hydration of volcanic glass, silica released detrital amorphous alumino-silicates that accumulated in muds, and decomposition of feldspars.  Silica release in shale does not necessarily source sandstone diagenesis but may...... of the biogenic silica has been transformed into opal-CT and partly to microcrystalline quartz.  The microcrystalline quartz is an internal sink for dissolved silica, but the shale may also have been an active silica exporter during this transition. With deeper burial (2000-2900m), opal-CT is fully transformed...... to microcrystalline quartz.  During this phase, silica has been partly mobile and depending on the rate of dissolution compared to the rate of precipitation, silica may have been lost to sandstone cementation.  Zeolite is also dissolved and mobilized silica may also have activated the shale as silica exporter...

  12. CO{sub 2} Injectivity, Storage Capacity, Plume Size, and Reservoir and Seal Integrity of the Ordovician St. Peter Sandstone and the Cambrian Potosi Formation in the Illnois Basin

    Energy Technology Data Exchange (ETDEWEB)

    Leetaru, Hannes; Brown, Alan; Lee, Donald; Senel, Ozgur; Coueslan, Marcia


    The Cambro-Ordovician strata of the Illinois and Michigan Basins underlie most of the states of Illinois, Indiana, Kentucky, and Michigan. This interval also extends through much of the Midwest of the United States and, for some areas, may be the only available target for geological sequestration of CO{sub 2}. We evaluated the Cambro-Ordovician strata above the basal Mt. Simon Sandstone reservoir for sequestration potential. The two targets were the Cambrian carbonate intervals in the Knox and the Ordovician St. Peter Sandstone. The evaluation of these two formations was accomplished using wireline data, core data, pressure data, and seismic data from the USDOE-funded Illinois Basin Decatur Project being conducted by the Midwest Geological Sequestration Consortium in Macon County, Illinois. Interpretations were completed using log analysis software, a reservoir flow simulator, and a finite element solver that determines rock stress and strain changes resulting from the pressure increase associated with CO{sub 2} injection. Results of this research suggest that both the St. Peter Sandstone and the Potosi Dolomite (a formation of the Knox) reservoirs may be capable of storing up to 2 million tonnes of CO{sub 2} per year for a 20-year period. Reservoir simulation results for the St. Peter indicate good injectivity and a relatively small CO{sub 2} plume. While a single St. Peter well is not likely to achieve the targeted injection rate of 2 million tonnes/year, results of this study indicate that development with three or four appropriately spaced wells may be sufficient. Reservoir simulation of the Potosi suggest that much of the CO{sub 2} flows into and through relatively thin, high permeability intervals, resulting in a large plume diameter compared with the St. Peter.

  13. Chemostratigraphic and sedimentologic evolution of Wajid Group (Wajid Sandstone): An outcrop analog study from the Cambrian to Permian, SW Saudi Arabia (United States)

    Yassin, Mohamed A.; Abdullatif, Osman M.


    The Paleozoic age succession in Saudi Arabia represents one of the most prolific petroleum producing systems in the Arabian Peninsula. This succession is also considered important for unconventional tight gas and shale gas reservoirs. The Wajid Group (Wajid Sandstone) in SW Saudi Arabia consists of four formations, namely, Dibsiyah (Lower and Upper), Sanamah, Khusayyayn and Juwayl from bottom to top. This study investigates the major oxides, trace and rare earth elements for the Wajid Group formations in southwestern Saudi Arabia. We characterize and compare the sandstone types, provenance, tectonic setting, and climate. Moreover, we applied the chemostratigraphic technique for stratigraphic differentiation. Concentrations of certain elements indicate that Wajid Group was deposited in a passive continental margin. The geochemical analysis reveals that Wajid Group sediments were likely derived from the upper and bulk continental crust and mafic igneous provenance. The elemental geochemical data has been applied in this study to improve the stratigraphic subdivision and correlation. Using selected elements, geochemical vertical profiles, binary, and ternary diagrams allow clearly distinguishing between Wajid Group formations. Thus supports the established formation boundaries that constructed using lithostratigraphy and sedimentology. The geochemical elements variation between formations can be related to differences in rock-forming minerals, facies change, climate, and provenance. The results of this study may help in constraining and correlating complex facies strata and can be used as a guide for stratigraphic correlations in the subsurface within the Wajid basin and other equivalent stratigraphic successions within Saudi Arabia.

  14. Formation and dissolution of zeolite during burial diagenesis - Examples from glauconitic sandstones in the Palaeogene Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan B

    or diagenetic alteration of volcanic glass. Authigenic zeolites are uncommon constituents in most sandstones. However, authigenic zeolites are common in some of the glauconitic sandstones from the Siri Canyon, where it is generally associated with thick coatings of opal/microquartz on the detrital framework...... Paleocene–early Eocene volcanic ash layers. Zeolites have a hydrated alumosilicate framework with varying amounts of alkali and alkaline earth metals.Authigenic zeolites may be common in deep marine sediments, and in volcanoclastic deposits. They are generally related to dissolution of siliceous fossils...

  15. Black shale source rocks and oil generation in the Cambrian and Ordovician of the central Appalachian Basin, USA (United States)

    Ryder, R.T.; Burruss, R.C.; Hatch, J.R.


    Nearly 600 million bbl of oil (MMBO) and 1 to 1.5 trillion ft3 (tcf) of gas have been produced from Cambrian and Ordovician reservoirs (carbonate and sandstone) in the Ohio part of the Appalachian basin and on adjoining arches in Ohio, Indiana, and Ontario, Canada. Most of the oil and gas is concentrated in the giant Lima-Indiana field on the Findlay and Kankakee arches and in small fields distributed along the Knox unconformity. Based on new geochemical analyses of oils, potential source rocks, bitumen extracts, and previously published geochemical data, we conclude that the oils in both groups of fields originated from Middle and Upper Ordovician blcak shale (Utica and Antes shales) in the Appalachian basin. Moroever, we suggest that approximately 300 MMBO and many trillions of cubic feet of gas in the Lower Silurian Clinton sands of eastern Ohio originated in the same source rocks. Oils from the Cambrian and Ordovician reservoirs have similar saturated hydrocarbon compositions, biomarker distributions, and carbon isotope signatures. Regional variations in the oils are attributed to differences in thermal maturation rather than to differences in source. Total organic carbon content, genetic potential, regional extent, and bitument extract geochemistry identify the balck shale of the Utica and Antes shales as the most plausible source of the oils. Other Cambrian and Ordovician shale and carbonate units, such as the Wells Creek formation, which rests on the Knox unconformity, and the Rome Formation and Conasauga Group in the Rome trough, are considered to be only local petroleum sources. Tmax, CAI, and pyrolysis yields from drill-hole cuttings and core indicate that the Utica Shale in eastern and central Ohio is mature with respect to oil generation. Burial, thermal, and hydrocarbon-generation history models suggest that much of the oil was generated from the Utica-Antes source in the late Paleozoic during the Alleghanian orogeny. A pervasive fracture network

  16. Diagenetic effect on permeabilities of geothermal sandstone reservoirs

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

    The Danish subsurface contains abundant sedimentary deposits, which can be utilized for geothermal heating. The Upper Triassic – Lower Jurassic continental-marine sandstones of the Gassum Formation has been utilised as a geothermal reservoir for the Thisted Geothermal Plant since 1984 extracting...... and permeability is caused by increased diagenetic changes of the sandstones due to increased burial depth and temperatures. Therefore, the highest water temperatures typically correspond with the lowest porosities and permeabilities. Especially the permeability is crucial for the performance of the geothermal......-line fractures. Continuous thin chlorite coatings results in less porosity- and permeability-reduction with burial than the general reduction with burial, unless carbonate cemented. Therefore, localities of sandstones characterized by these continuous chlorite coatings may represent fine geothermal reservoirs...

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  18. Causes of the Cambrian Explosion

    National Research Council Canada - National Science Library

    M. Paul Smith; David A. T. Harper


    .... Recent hypotheses for the Cambrian explosion fall into three main categories: developmental/genetic, ecologic, and abiotic/environmental, with geochemical hypotheses forming an abundant and distinctive subset of the last...

  19. Oxygen-isotope trends and seawater temperature changes across the Late Cambrian Steptoean positive carbon-isotope excursion (SPICE event) (United States)

    Elrick, M.; Rieboldt, S.; Saltzman, M.; McKay, R.M.


    The globally recognized Late Cambrian Steptoean positive C-isotope excursion (SPICE) is characterized by a 3???-5??? positive ??13C shift spanning thermohaline circulation rates contributed to decreased dissolved O2 concentrations, which enhanced the preservation/burial of Corg causing the positive ??13C shift. ?? 2011 Geological Society of America.

  20. Depositional Architecture of Late Cambrian-Early Ordovician Siliciclastic Barik Formation; Al Huqf Area, Oman (United States)

    Abbasi, Iftikhar Ahmed


    Early Paleozoic siliciclastics sediments of the Haima Supergroup are subdivided into a number of formations and members based on lithological characteristics of various rock sequences. One of the distinct sandstone sequence, the Barik Formation (Late Cambrian-Early Ordovician) of the Andam Group is a major deep gas reservoir in central Oman. The sandstone bodies are prospective reservoir rocks while thick shale and clay interbeds act as effective seal. Part of the Barik Formation (lower and middle part) is exposed in isolated outcrops in Al Huqf area as interbedded multistoried sandstone, and green and red shale. The sandstone bodies are up to 2 meters thick and can be traced laterally for 300 m to over 1 km. Most of sandstone bodies show both lateral and vertical stacking. Two types of sandstone lithofacies are identified on the basis of field characteristics; a plane-bedded sandstone lithofacies capping thick red and green color shale beds, and a cross-bedded sandstone lithofacies overlying the plane-bedded sandstone defining coarsening upward sequences. The plane-bedded sandstone at places contains Cruziana ichnofacies and bivalve fragments indicating deposition by shoreface processes. Thick cross-bedded sandstone is interpreted to be deposited by the fluvial dominated deltaic processes. Load-casts, climbing ripples and flaser-bedding in siltstone and red shale indicate influence of tidal processes at times during the deposition of the formation. This paper summarizes results of a study carried out in Al Huqf area outcrops to analyze the characteristics of the sandstone-body geometry, internal architecture, provenance and diagenetic changes in the lower and middle part of the formation. The study shows build-up of a delta complex and its progradation over a broad, low-angle shelf where fluvial processes operate beside shoreface processes in a vegetation free setting. Keywords: Andam Group, Barik Formation, Ordovician sandstone, Al Huqf, Central Oman,

  1. Nodular features from Proterozoic Sonia Sandstone, Jodhpur Group ...

    Indian Academy of Sciences (India)

    solubility of silica drastically, and (ii) by provid- ing local seeds or templates to help silica nucle- ate (Knoll 1985; Simonson 1987). The amorphous silica cementation, in patches as fringe-cement, at the early stage of burial caused partial lithification of the sandstone and triggered inhomogeneous dia- genetic behaviour on ...

  2. Field demonstration of improved shallow land burial practices for low-level radioactive solid wastes: preliminary site characterization and progress report. [Trench liners and grout for improving shallow land burial

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, N.D.; Haase, C.S.; Huff, D.D.; Lee, S.Y.; Walls, E.C.


    A 5-year field demonstration (ETF) of improved shallow land burial practices for low-level radioactive solid wastes in a humid environment evaluates the use of a trench liner and grout as alternate trench treatments for improving shallow land burial site performance in the humid East. The ETF is located within the Copper Creek thrust block of the Valley and Ridge Province of east Tennessee and is underlain by strata of the Middle to Late Cambrian Conasauga Group. The Maryville Limestone formation, which is composed of ribbon-bedded and interclastic limestones and dark grey shales and mudstones, comprises the bedrock immediately beneath the site. The bedrock and residuum structure are characterized by anticlinal folds with numerous joints and fractures, some of which are filled with calcite. Seismic and electrical resistivity geophysical methods were useful in characterizing the thickness of residuum and presence of structural features. Soils are illitic and range from podzolic to lithosols to alluvial in the vicinity of the ETF, but the original soil solum was removed in 1975 when the mixed hardwood forest was cleared and the site was planted in grasses. The remaining residuum consists of acidic soil aggregate and extensively weathered siltstone and sandstone which exhibit the original rock structure. Mean annual precipitation at the site is 1500 mm, although during the initial study period (10-1-80 to 9-30-81) the annual total was 939 mm. Runoff was estimated to be about 50% of the precipitation total, based on observations at two Parshall flumes installed at the site. Storm runoff is quite responsive to rainfall, and the lag time between peak rainfall and runoff is less than 15 min during winter storms. Tracer studies of the ground-water system, suggest that ground-water flow has two distinct components, one associated with fracture flow and the other with intergranular flow.

  3. Fe-oxide grain coatings support bacterial Fe-reducing metabolisms in 1.7-2.0 km-deep subsurface quartz arenite sandstone reservoirs of the Illinois Basin (USA

    Directory of Open Access Journals (Sweden)

    Yiran eDong


    Full Text Available The Cambrian-age Mt. Simon Sandstone, deeply buried within the Illinois Basin of the midcontinent of North America, contains quartz sand grains ubiquitously encrusted with iron-oxide cements and dissolved ferrous iron in pore-water. Although microbial iron reduction has previously been documented in the deep terrestrial subsurface, the potential for diagenetic mineral cementation to drive microbial activity has not been well studied. In this study, two subsurface formation water samples were collected at 1.72 and 2.02 km, respectively, from the Mt. Simon Sandstone in Decatur, Illinois. Low-diversity microbial communities were detected from both horizons and were dominated by Halanaerobiales of Phylum Firmicutes. Iron-reducing enrichment cultures fed with ferric citrate were successfully established using the formation water. Phylogenetic classification identified the enriched species to be related to Vulcanibacillus from the 1.72 km depth sample, while Orenia dominated the communities at 2.02 km of burial depth. Species-specific quantitative analyses of the enriched organisms in the microbial communities suggest that they are indigenous to the Mt. Simon Sandstone. Optimal iron reduction by the 1.72 km enrichment culture occurred at a temperature of 40oC (range 20 to 60oC and a salinity of 25 parts per thousand (range 25-75 ppt. This culture also mediated fermentation and nitrate reduction. In contrast, the 2.02 km enrichment culture exclusively utilized hydrogen and pyruvate as the electron donors for iron reduction, tolerated a wider range of salinities (25-200 ppt, and exhibited only minimal nitrate- and sulfate-reduction. In addition, the 2.02 km depth community actively reduces the more crystalline ferric iron minerals goethite and hematite. The results suggest evolutionary adaptation of the autochthonous microbial communities to the Mt. Simon Sandstone and carries potentially important implications for future utilization of this reservoir

  4. Hydrogeology and simulation of ground-water flow in the Sandstone Aquifer, northeastern Wisconsin (United States)

    Conlon, T.D.


    Municipalities in the lower Fox River Valley in northeastern Wisconsin obtain their water supply from a series of permeable sandstones and carbonates of Cambrian to Ordovician age. Withdrawals from this "sandstone aquifer" have resulted in water levels declining at a rate of more than 2 feet per year. The U.S. Geological Survey, in cooperation with the major water utilities in the Fox Cities area, the East Central Wisconsin Regional Planning Commission and the Wisconsin Geological and Natural History Survey, collected hydrogeological data and constructed a quasithree- dimensional, transient ground-water-flow model for use as a tool in assessing the water resources of the sandstone aquifer.

  5. A refined genetic model for the Laisvall and Vassbo Mississippi Valley-type sandstone-hosted deposits, Sweden: constraints from paragenetic studies, organic geochemistry, and S, C, N, and Sr isotope data (United States)

    Saintilan, Nicolas J.; Spangenberg, Jorge E.; Samankassou, Elias; Kouzmanov, Kalin; Chiaradia, Massimo; Stephens, Michael B.; Fontboté, Lluís


    The current study has aimed to refine the previously proposed two-fluid mixing model for the Laisvall (sphalerite Rb-Sr age of 467 ± 5 Ma) and Vassbo Mississippi Valley-type deposits hosted in Ediacaran to Cambrian sandstone, Sweden. Premineralization cements include authigenic monazite, fluorapatite, and anatase in the Upper Sandstone at Laisvall, reflecting anoxic conditions during sandstone burial influenced by the euxinic character of the overlying carbonaceous middle Cambrian to Lower Ordovician Alum Shale Formation ( δ 13Corg = -33.0 to -29.5 ‰, δ 15Norg = 1.5 to 3.3 ‰, 0.33 to 3.03 wt% C, 0.02 to 0.08 wt% N). The available porosity for epigenetic mineralization, including that produced by subsequent partial dissolution of pre-Pb-Zn sulfide calcite and barite cements, was much higher in calcite- and barite-cemented sandstone paleoaquifers (29 % by QEMSCAN mapping) than in those mainly cemented by quartz (8 %). A major change in the Laisvall plumbing system is recognized by the transition from barite cementation to Pb-Zn sulfide precipitation in sandstone. Ba-bearing, reduced, and neutral fluids had a long premineralization residence time (highly radiogenic 87S/86Sr ratios of 0.718 to 0.723) in basement structures. As a result of an early Caledonian arc-continent collision and the development of a foreland basin, fluids migrated toward the craton and expelled Ba-bearing fluids from their host structures into overlying sandstone where they deposited barite upon mixing with a sulfate pool ( δ 34Sbarite = 14 to 33 ‰). Subsequently, slightly acidic brines initially residing in pre-Ediacaran rift sediments in the foredeep of the early Caledonian foreland basin migrated through the same plumbing system and acquired metals on the way. The bulk of Pb-Zn mineralization formed at temperatures between 120 and 180 °C by mixing of these brines with a pool of H2S ( δ 34S = 24 to 29 ‰) produced via thermochemical sulfate reduction (TSR) with oxidation of

  6. On the origin and glacial transport of erratics of Jotnian sandstone in southwestern Finland

    Directory of Open Access Journals (Sweden)

    Donner, J.


    Full Text Available Late Proterozoic Jotnian sandstone erratics were transported during the last Quaternary glaciation from the source area in Satakunta at the coast of southwestern Finland and the bottom of the Bothnian Sea to the southeast as far as Estonia, Latvia and Russia. The frequencies of the sandstone erratics show that they were transported greater distances than indicators of other rocks in the southern parts of Finland. In addition, high frequencies in small areas, south of Salo and in Bromarv, indicate that there are or were small separate source areas of Jotnian sandstone outside the main area. This is supported by the distribution of erratics of Cambrian sandstone and Ordovician sedimentary rocks in the same area. The tracing of possible small occurrences of Jotnian sandstone or Palaeozoic rocks is, however, difficult in an area with numerous faults and fracture zones in the Precambrian bedrock, where the depressions are covered by thick Quaternary drift.

  7. Genesis of early Cambrian phosphorite of Krol Belt, Lesser Himalaya

    Digital Repository Service at National Institute of Oceanography (India)

    Mazumdar, A.; Banerjee, D.M.

    for the modern Peru–Chile shelf–slope phosphorite is inadequate to explain the genesis of Cambrian phosphorite. Physicochemical characters of the Cambrian phosphorites demand a shallow marine phosphorous source. Based on the available early Cambrian oceanographic...

  8. 78 FR 76574 - Burial Benefits (United States)


    ... World War II veterans, Congress' clear motivation was to make burial benefits ``easier to administer, i... definition of ``burial.'' Under the proposed rule, the definition would be placed at the beginning of the... Deceased Veterans for Whom VA May Provide Burial Benefits Under the definition in 38 U.S.C. 101(2), a...

  9. Kaolinite Mobilisation in Sandstone

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke; Kets, Frans


    The effect of temperature and salinity on sandstone permeability is critical to the feasibility of heat storage in geothermal aquifers. Permeability reduction has been observed in Berea sandstone when the salinity of the pore water is reduced as well as when the sample is heated. Several authors...... suggest that this effect is due to kaolinite clay mobilisation from the quartz grain surface; the mobilised particles subsequently plug the pore throats and reduce the permeability irreversibly. The expected hysteresis is observed when the salinity is reduced and increased; however, in contradiction...... with the throat plugging theory, the effect of heating is found to be reversible with cooling. In laboratory experiments we heated Berea sandstone from 20oC to 80oC and observed a reversible permeability reduction. The permeability of the heated samples increased at higher flow rates. We propose that in this case...

  10. Taking the pulse of the cambrian radiation. (United States)

    Lieberman, Bruce S


    The Cambrian radiation is that key episode in the history of life when a large number of animal phyla appeared in the fossil record over a geologically short period of time. Over the last 20 years, scientific understanding of this radiation has increased significantly. Still, fundamental questions remain about the timing of the radiation and also the tempo of evolution. Trilobites are an excellent group to address these questions because of their rich abundance and diversity. Moreover, their complex morphology makes them readily amenable to phylogenetic analysis, and deducing the nature of macroevolutionary processes during the Cambrian radiation requires an understanding of evolutionary patterns. Phylogenetic biogeographic analysis of Early Cambrian olenellid trilobites, based on a modified version of Brooks Parsimony Analysis, revealed the signature of the breakup of Pannotia, a tectonic event that most evidence suggests is constrained to the interval 600 to 550 Ma. As trilobites are derived metazoans, this suggests the phylogenetic proliferation associated with the Cambrian radiation was underway tens of millions of years before the Early Cambrian, although not hundreds of millions of years as some have argued.Phylogenetic information from Early Cambrian olenellid trilobites was also used in a stochastic approach based on two continuous time models to test the hypothesis that rates of speciation were unusually high during the Cambrian radiation. No statistical evidence was found to support this hypothesis. Instead, rates of evolution during the Cambrian radiation, at least those pertaining to speciation, were comparable to those that have occurred during other times of adaptive or taxic radiation throughout the history of life.

  11. Burial Ground Expansion Hydrogeologic Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Gaughan , T.F.


    Sirrine Environmental Consultants provided technical oversight of the installation of eighteen groundwater monitoring wells and six exploratory borings around the location of the Burial Ground Expansion.

  12. Predicting cement distribution in geothermal sandstone reservoirs based on estimates of precipitation temperatures (United States)

    Olivarius, Mette; Weibel, Rikke; Whitehouse, Martin; Kristensen, Lars; Hjuler, Morten L.; Mathiesen, Anders; Boyce, Adrian J.; Nielsen, Lars H.


    Exploitation of geothermal sandstone reservoirs is challenged by pore-cementing minerals since they reduce the fluid flow through the sandstones. Geothermal exploration aims at finding sandstone bodies located at depths that are adequate for sufficiently warm water to be extracted, but without being too cemented for warm water production. The amount of cement is highly variable in the Danish geothermal reservoirs which mainly comprise the Bunter Sandstone, Skagerrak and Gassum formations. The present study involves bulk and in situ stable isotope analyses of calcite, dolomite, ankerite, siderite and quartz in order to estimate at what depth they were formed and enable prediction of where they can be found. The δ18O values measured in the carbonate minerals and quartz overgrowths are related to depth since they are a result of the temperatures of the pore fluid. Thus the values indicate the precipitation temperatures and they fit the relative diagenetic timing identified by petrographical observations. The sandstones deposited during arid climatic conditions contain calcite and dolomite cement that formed during early diagenesis. These carbonate minerals precipitated as a response to different processes, and precipitation of macro-quartz took over at deeper burial. Siderite was the first carbonate mineral that formed in the sandstones that were deposited in a humid climate. Calcite began precipitating at increased burial depth and ankerite formed during deep burial and replaced some of the other phases. Ankerite and quartz formed in the same temperature interval so constrains on the isotopic composition of the pore fluid can be achieved. Differences in δ13C values exist between the sandstones that were deposited in arid versus humid environments, which suggest that different kinds of processes were active. The estimated precipitation temperatures of the different cement types are used to predict which of them are present in geothermal sandstone reservoirs in

  13. Cambrian-lower Middle Ordovician passive carbonate margin, southern Appalachians: Chapter 14 (United States)

    Read, J. Fred; Repetski, John E.


    The southern Appalachian part of the Cambrian–Ordovician passive margin succession of the great American carbonate bank extends from the Lower Cambrian to the lower Middle Ordovician, is as much as 3.5 km (2.2 mi) thick, and has long-term subsidence rates exceeding 5 cm (2 in.)/k.y. Subsiding depocenters separated by arches controlled sediment thickness. The succession consists of five supersequences, each of which contains several third-order sequences, and numerous meter-scale parasequences. Siliciclastic-prone supersequence 1 (Lower Cambrian Chilhowee Group fluvial rift clastics grading up into shelf siliciclastics) underlies the passive margin carbonates. Supersequence 2 consists of the Lower Cambrian Shady Dolomite–Rome-Waynesboro Formations. This is a shallowing-upward ramp succession of thinly bedded to nodular lime mudstones up into carbonate mud-mound facies, overlain by lowstand quartzose carbonates, and then a rimmed shelf succession capped by highly cyclic regressive carbonates and red beds (Rome-Waynesboro Formations). Foreslope facies include megabreccias, grainstone, and thin-bedded carbonate turbidites and deep-water rhythmites. Supersequence 3 rests on a major unconformity and consists of a Middle Cambrian differentiated rimmed shelf carbonate with highly cyclic facies (Elbrook Formation) extending in from the rim and passing via an oolitic ramp into a large structurally controlled intrashelf basin (Conasauga Shale). Filling of the intrashelf basin caused widespread deposition of thin quartz sandstones at the base of supersequence 4, overlain by widespread cyclic carbonates (Upper Cambrian lower Knox Group Copper Ridge Dolomite in the south; Conococheague Formation in the north). Supersequence 5 (Lower Ordovician upper Knox in the south; Lower to Middle Ordovician Beekmantown Group in the north) has a basal quartz sandstone-prone unit, overlain by cyclic ramp carbonates, that grade downdip into thrombolite grainstone and then storm

  14. Hydrogeology of the Potsdam Sandstone in northern New York (United States)

    Williams, John H.; Reynolds, Richard J.; Franzi, David A.; Romanowicz, Edwin A.; Paillet, Frederick L.


    The Potsdam Sandstone of Cambrian age forms a transboundary aquifer that extends across northern New York and into southern Quebec. The Potsdam Sandstone is a gently dipping sequence of arkose, subarkose, and orthoquartzite that unconformably overlies Precambrian metamorphic bedrock. The Potsdam irregularly grades upward over a thickness of 450 m from a heterogeneous feldspathic and argillaceous rock to a homogeneous, quartz-rich and matrix-poor rock. The hydrogeological framework of the Potsdam Sandstone was investigated through an analysis of records from 1,500 wells and geophysical logs from 40 wells, and through compilation of GIS coverages of bedrock and surficial geology, examination of bedrock cores, and construction of hydrogeological sections. The upper several metres of the sandstone typically is weathered and fractured and, where saturated, readily transmits groundwater. Bedding-related fractures in the sandstone commonly form sub-horizontal flow zones of relatively high transmissivity. The vertical distribution of sub-horizontal flow zones is variable; spacings of less than 10 m are common. Transmissivity of individual flow zones may be more than 100 m2/d but typically is less than 10 m2/d. High angle fractures, including joints and faults, locally provide vertical hydraulic connection between flow zones. Hydraulic head gradients in the aquifer commonly are downward; a laterally extensive series of sub-horizontal flow zones serve as drains for the groundwater flow system. Vertical hydraulic head differences between shallow and deep flow zones range from 1 m to more than 20 m. The maximum head differences are in recharge areas upgradient from the area where the Chateauguay and Chazy Rivers, and their tributaries, have cut into till and bedrock. Till overlies the sandstone in much of the study area; its thickness is generally greatest in the western part, where it may exceed 50 m. A discontinuous belt of bedrock pavements stripped of glacial drift extends

  15. Geochemistry of the Cambrian-Ordovician aquifer system in the northern Midwest, United States: D in Regional aquifer-system analysis (United States)

    Siegel, D.I.


    Distributions of solutes in aquifers of Cambrian and Ordovician age were studied in Minnesota, Wisconsin, Iowa, Illinois, northwestern Indiana, and northern Missouri to determine the sources of solutes and the probable chemical mechanisms that control regional variations in water quality. This work is part of the Northern Midwest Regional Aquifer-System Analysis project, whose objective is to describe and model the regional hydrogeology of the Cambrian- Ordovician aquifer system in the study region. The data base used included more than 3,000 ground-water-quality analyses from all major aquifers, but especially from the St. Peter, Jordan, and Mount Simon Sandstones and their equivalents. Regional variations in the water chemistry of glacial drift and other sedimentary units that overlie the Cambrian-Ordovician aquifer system in recharge areas in Minnesota, Iowa, Wisconsin, and Illinois were also studied, but to a lesser degree.

  16. Overpressure by burial (United States)

    Podladchikov, Yury; Dabrowski, Marcin


    Preservation of peak metamorphic assemblages cannot be explain by sluggish kinetics only due to high temperatures. Moreover, frequently reported near isothermal decompression from peak conditions testify continuing capacity of lower pressure metamorphic reactions to overcome kinetic barriers. Often these observations come from the same rock sample, or even or from a single host crystal. Natural conclusion on preservation of peak pressures in a 'pressure vessel' in order to preserve the peak mineral assemblages was firmly made already in the first years after convincing identifying of ultra-high pressure minerals in continental rocks. The 'pressure vessels' model is thus the current view on mechanical state during retrogression assuming up to several GPa excess pressure in inclusion maintained by host mineral all the way through retrogression. Same arguments apply to preservation of outcrop scale eclogite boudins in lower pressure amphibolite gneisses. If strength of rocks and minerals is sufficient to keep the pressure difference during retrogression, the same applies to the prograde stage of the metamorphic history of the rock. We investigate and quantify the overpressure development during burial of continental rocks. We show that eclogite lenses are expected to develop over mafic lithology embedded in average crustal rock at lower crustal condition, thus eliminating the need for 'deep continental subduction' as the only mechanism to form it.

  17. Upper lower Cambrian (provisional Cambrian Series 2 trilobites from northwestern Gansu Province, China

    Directory of Open Access Journals (Sweden)

    Jan Bergström†


    Full Text Available Upper lower Cambrian (provisional Cambrian Series 2 trilobites are described from three sections through the Shuangyingshan Formation in the Beishan area, northwestern Gansu Province, China. The trilobite fauna is dominated by eodiscoid and corynexochid trilobites, together representing at least ten genera: Serrodiscus, Tannudiscus, Calodiscus, Pagetides, Kootenia, Edelsteinaspis, Ptarmiganoides?, Politinella, Dinesus and Subeia. Eleven species are described, of which seven are identified with previously described taxa and four described under open nomenclature. The composition of the fauna suggests biogeographic affinity with Siberian rather than Gondwanan trilobite faunas, and the Cambrian Series 2 faunas described herein and from elsewhere in northwestern China seem to be indicative of the marginal areas of the Siberian palaeocontinent. This suggests that the Middle Tianshan–Beishan Terrane may have been located fairly close to Siberia during middle–late Cambrian Epoch 2.

  18. Diversity partitioning during the Cambrian radiation. (United States)

    Na, Lin; Kiessling, Wolfgang


    The fossil record offers unique insights into the environmental and geographic partitioning of biodiversity during global diversifications. We explored biodiversity patterns during the Cambrian radiation, the most dramatic radiation in Earth history. We assessed how the overall increase in global diversity was partitioned between within-community (alpha) and between-community (beta) components and how beta diversity was partitioned among environments and geographic regions. Changes in gamma diversity in the Cambrian were chiefly driven by changes in beta diversity. The combined trajectories of alpha and beta diversity during the initial diversification suggest low competition and high predation within communities. Beta diversity has similar trajectories both among environments and geographic regions, but turnover between adjacent paleocontinents was probably the main driver of diversification. Our study elucidates that global biodiversity during the Cambrian radiation was driven by niche contraction at local scales and vicariance at continental scales. The latter supports previous arguments for the importance of plate tectonics in the Cambrian radiation, namely the breakup of Pannotia.

  19. The Vakkejokk Breccia: An Early Cambrian proximal impact ejecta layer in the North-Swedish Caledonides (United States)

    Ormö, J.; Nielsen, A. T.; Alwmark, C.


    The ≤27 m thick Vakkejokk Breccia is intercalated in autochthon Lower Cambrian along the Caledonian front north of Lake Torneträsk, Lapland, Sweden. The spectacular breccia is here interpreted as a proximal ejecta layer associated with an impact crater, probably 2-3 km in size, located below Caledonian overthrusts immediately north of the main breccia section. The impact would have taken place in a shallow-marine environment 520 Ma ago. The breccia comprises i) a strongly disturbed lower polymict subunit with occasional, in themselves brecciated, crystalline mega-clasts locally exceeding 50 m surrounded by contorted sediments; ii) a middle, commonly normally graded, crystalline-rich, polymict subunit, in turn locally overlain by iii) a thin fine-grained quartz sandstone, mobilization of the sediments. The middle subunit and the uppermost quartz sandstone are considered resurge deposits. The top conglomerate may be caused by subsequent wave reworking and slumping of material from the elevated rim. Quartz grains showing planar deformation features are present in the graded polymict subunit and the upper sandstone, that is, the inferred resurge deposits.

  20. An Early Cambrian stem polychaete with pygidial cirri


    Vinther, Jakob; Eibye-Jacobsen, Danny; Harper, David A.T.


    The oldest annelid fossils are polychaetes from the Cambrian Period. They are representatives of the annelid stem group and thus vital in any discussion of how we polarize the evolution of the crown group. Here, we describe a fossil polychaete from the Early Cambrian Sirius Passet fauna, Pygocirrus butyricampum gen. et sp. nov., with structures identified as pygidial cirri, which are recorded for the first time from Cambrian annelids. The body is slender and has biramous parapodia with chaeta...

  1. 38 CFR 3.954 - Burial allowance. (United States)


    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Burial allowance. 3.954..., Compensation, and Dependency and Indemnity Compensation Protection § 3.954 Burial allowance. When any person... benefits dies, the burial allowance will be paid, if otherwise in order, even though such status does not...

  2. Cambrian rivers and floodplains: the significance of microbial cementation, groundwater and aeolian sediment transport (United States)

    Reesink, A. J. H.; Best, J.; Freiburg, J. T.; Nathan, W.


    Rivers that existed before land plants colonized the Earth are commonly considered to be unaffected by microbial activity on their floodplains, because the limited cementation produced by microbial activity is insufficient to stabilize the river banks. Although this assumption is likely correct, such emphasis on channel dynamics ignores the potential role of floodplain dynamics as an integral component of the river system. Detailed analysis of cores from the Cambrian Mount Simon Sandstone, Illinois, suggests that a significant proportion of the terrestrial sequence is composed of flat-bedded `crinkly' structures that provide evidence of cementation by soil crusts and microbial biofilms, and that promoted the adhesion of sediment to sticky surfaces. Wind ripples and local desert pavements were abundant. These findings highlight that sediment deposition on Cambrian floodplains was often dominated by wind in locations where the ground water table reached the surface, and was thus likely independent of sediment transport within the river channel. Erosion by wind would thus have been hindered by surface cementation and the formation of desert pavements. Such ground water control on deposition, and resistance to erosion by floodplain surface hardening, appear to have been the primary controls on Cambrian floodplain topography. Because floodplain topography poses a key control on channel and floodplain flow, these processes may have affected patterns of erosion and deposition, as well as reach-scale dynamics such as channel avulsions. The autonomous operation of wind-and-groundwater controlled floodplains makes pre-vegetated river systems more sensitive to climatic conditions such as precipitation and evaporation, and strikingly different from those that occurred after the development of land plants.

  3. Sandstone Turning by Abrasive Waterjet

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Petr; Cárach, J.; Hloch, Sergej; Vasilko, K.; Klichová, Dagmar; Klich, Jiří; Lehocká, D.


    Roč. 48, č. 6 (2015), s. 2489-2493 ISSN 0723-2632 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : turning away from the jet * conventional turning towards the jet * sandstone * abrasive water jet Subject RIV: JQ - Machines ; Tools Impact factor: 2.386, year: 2015

  4. Ichnology of the Early Cambrian Tal Group, Mussoorie Syncline ...

    Indian Academy of Sciences (India)

    blage along with earlier ichnofossils and other faunal occurrences substantiates the assignment of Early. Cambrian age to the ... Trace fossils; Dhaulagiri Formation; Tal Group; Early Cambrian; Lesser Himalaya; India. J. Earth Syst. Sci. 122, No ..... Middlemiss C S 1887 Physical geology of west British. Garhwal with notes on ...

  5. EBSD characterization of pre-Cambrian deformations in conglomerate pebbles (Sierra de la Demanda, Northern Spain) (United States)

    Puelles, Pablo; Ábalos, Benito; Fernández-Armas, Sergio


    Pre-Cambrian and unconformable earliest Cambrian rocks from the Sierra de la Demanda (N Spain) exhibit field and microstructural relationships that attest to orogenic events recorded by concealed basement rocks. Neoproterozoic foliated slates ("Anguiano Schists") crop out under up to 300 m thick, unfoliated quartz-rich conglomerates ("Anguiano Conglomerates") and quartzites which are stratigraphically ca. 600 m below the oldest, paleontologically dated, pre-trilobitic Cambrian layers (likely older than 520 Ma). The Anguiano Conglomerates contain mm to cm grainsized well-rounded pebbles of various types including monocrystalline quartz, detrital zircon and tourmaline-bearing sandstones, black cherts and metamorphic poly-crystalline quartz aggregates. The undeformed matrix is made of much smaller (diagenetically overgrown) monocrystaline quartz grains and minor amounts of accesory zircon, tourmaline and mica. Black chert pebbles exhibit microstructural evidence of brittle deformation (microfaults and thin veins of syntaxial fibrous quartz). These and the fine-grained sandstone pebbles can also exhibit ductile deformations (microfolds with thickened hinges and axial planar continuous foliations), too. Polycrystalline quartz pebbles exhibit a variety of microstructures that resulted from syn-metamorphic ductile deformations. These are recognisable under the petrographic microscope and include continuous foliations, quartz shape fabrics, various types of subgrain or recrystallized new grain microtextures, and lattice preferred orientations (LPOs). Conventional characterization of quartz fabrics (after oriented structural sections) is challenged in conglomerate pebble thin sections by the difficulty of unraveling in them the complete structural reference framework provided by foliation (whose trace can be unraveled) and lineation orientation (which cannot be directly identified). Quartz in various metamorphic polycrystalline pebbles was studied with the Electron Back

  6. Early Cambrian palaeogeography and the probable Iberia Siberia connection (United States)

    Gubanov, Alexander P.


    The end of the Proterozoic-beginning of the Cambrian is marked by some of the most dramatic events in the history of Earth. The fall of the Ediacaran biota, followed by the Cambrian Explosion of skeletonised bilaterians, a pronounced shift in oceanic and atmospheric chemistry and rapid climatic change from 'snowball earth' to 'greenhouse' conditions all happened within a rather geologically short period of time. These events took place against a background of the rearrangement of the prevailing supercontinent; some authors view this as a sequence of individual supercontinents such as Mesoproterozoic Midgardia, Neoproterozoic Rodinia and Early Cambrian Pannotia. Assembled in the Mesoproterozoic, this supercontinent appears to have existed through the Neoproterozoic into the Early Cambrian with periodic changes in configuration. The final rearrangement took place during the Precambrian-Cambrian transition with the Cadomian and related phases of the Pan-African orogeny. The distribution of Early Cambrian molluscs and other small shelly fossils (SSF) across all continents indicates a close geographic proximity of all major cratonic basins that is consistent with the continued existence of the supercontinent at that time. Subsequently, Rodinia experienced breakup that led to the amalgamation of Gondwana, separation of Laurentia, Baltica, Siberia and some small terranes and the emergence of oceanic basins between them. Spreading oceanic basins caused a gradual geographic isolation of the faunal assemblages that were united during the Vendian-Early Cambrian.

  7. Carbon sequestration via wood burial

    Directory of Open Access Journals (Sweden)

    Zeng Ning


    Full Text Available Abstract To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1, followed by temperate (3.7 GtC y-1 and boreal forests (2.1 GtC y-1. Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC, lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.

  8. Evidence for monophyly and arthropod affinity of cambrian giant predators. (United States)

    Chen, J Y; Ramsköld, L; Zhou, G Q


    The Chinese Early Cambrian Chengjiang fauna includes three different anomalocaridids, a globally spread, extinct marine group including the largest known Cambrian animals. Anomalocaridids were active predators, and their presence implies that a complex ecosystem appeared abruptly in the earliest Phanerozoic. Complete specimens display several sets of characters shared only with some other exclusively Cambrian forms. This evidence indicates that anomalocaridids, Opabinia, and Kerygmachela form a monophyletic clade. Certain features indicate arthropod affinities of the lade, and for this group an unnamed (sub)phylum-level taxon within an arthropod (super)phylum is proposed.

  9. The Tastil batholith (Cordillera Oriental, Argentina): a case of lower Cambrian extensional-related magmatism in the border of Gondwana. (United States)

    Hongn, F.; Tubía, J. M.; Aranguren, A.; Mon, R.


    The Tastil batholith composed of gray granodiorite, red granite and dacite porphiry, intrudes into weakly metamorphosed turbidites (usually included in the Puncoviscana Formation) and into Cambrian shelf sandstones belonging to the Lower-Middle Cambrian Mesón Group deposited in an intracontinental extensional basin. Tremadocian fossiliferous conglomerates overlying the sandstones of the Mesón Group incorporate red granite pebbles in the Angosto de la Quesera section, the classical section for interpreting the stratigraphic relationships of the Tastil batholith. U-Pb zircon ages from a dacite porphiry (526 Ma) and red granite (517 Ma) are consistent with such field relationships. This new view of the Tastil batholith implies that the previous interpretations of the basement, based on the supposed unconformity between the Mesón Group and the underlying red granite, and hence including the Tastil batholith in the basement, can not longer be sustained. The batholith emplacement is not related with the shortening happened during the late evolution of the Puncoviscana Formation (Pampean cycle) as always was interpreted, but with the extensional tectonics responsible for the development of the Mesón Group basin (Famatinian cycle). Along central and northern Argentina, the basement records a wide spectrum of sedimentary, deformational, magmatic and metamorphic processes occurred at different crustal levels during the Latest Neoproterozoic and the Cambrian. In this regard, the deposition of the Mesón Group and the intrusion of the Tastil batholith within the Cordillera Oriental can be correlated with the magmatism and the high-T/low-P metamorphism developed, at deeper levels, 530 to 500 Ma ago within the basement of the Puna and Sierras Pampeanas. In the same way, the sedimentation and igneous processes documented at shallower levels in the Sierras Pampeanas took place in this extensional tectonic scenario. The available data point to an overall extensional tectonics

  10. Middle to late Cambrian shallow marine trace fossils from the Imfout Syncline (Western Meseta, Morocco): Palaeoecological and palaeoenvironmental significance in NW-Gondwana (United States)

    Oukassou, Mostafa; Lagnaoui, Abdelouahed; Raji, Mohammed; Michard, André; Saddiqi, Omar


    The present research provides the first evidence of invertebrate activity assigned to the ichnogenus Selenichnites occurring together with moderately diverse ichnofossils from the middle to late Cambrian of the Moroccan Meseta. The invertebrate traces occur in sandstone strata of the El Hank Formation within the Imfout Syncline, in the northern part of the Rehamna Massif (Coastal Block, western Moroccan Meseta). Bedding surfaces from the top of the El Hank Formation near the Imfout Dam show diverse forms of current ripples and distincts crescentic ichnofossils in concave epirelief scattered on the surface. In this section, the traces provide evidence of the ethology of an organism inhabiting the relatively shallow waters of the area during this time. Selenichnites co-occurs with the ichnogenera Arenicolites, Diplocraterion, Lingulichnus, Monocraterion, Skolithos and unidentified burrows, and the ichnoassemblage is referred to the Skolithos ichnofacies. These traces can be referred to arthropods (e.g. polychaete worms and amphipod crustaceans), lingulid brachiopods, annelids and/or phoronids. The Imfout Selenichnites represents the first occurrence of this ichnogenus from the Cambrian of the Moroccan Meseta, and the second from the Cambrian deposits of Morocco. The potential tracemakers are still questionable, but were most likely xiphosurans, trilobites, euthycarcinoids or crustaceans. If so, the Imfout traces could be among the oldest pieces of evidence for the presence of horseshoe crabs during the Cambrian. The combination of sedimentological and ichnological data indicates that the El Hank Formation was deposited in a sublittoral soft ground environment next to a sandy shore. It was originally part of an early Palaeozoic shallow marine epicontinental platform in west-central Morocco. In addition to the equivalent Cambrian deposits from the Anti-Atlas, the El Hank Formation constituted a part of the northern Gondwana platform domain during the transgression

  11. Early Cambrian oxygen minimum zone-like conditions at Chengjiang

    DEFF Research Database (Denmark)

    Hammarlund, Emma U.; Gaines, Robert R.; Prokopenko, Maria G.


    chemistry, following the oxygenation of the surface ocean and of shallow marine environments during the Ediacaran Period, but prior to the establishment of a predominantly oxygenated deep ocean in the mid-Paleozoic. Despite recent attention, a detailed understanding of the chemical conditions that prevailed......The early Cambrian succession at Chengjiang contains the most diverse Cambrian fossil assemblage yet described, and contributes significantly to our understanding of the diversification of metazoans in the Cambrian “explosion”. The Cambrian Period occupies a transitional episode of global ocean......-column chemistry within the succession, which progressively shifted from euxinic to oxic conditions during deposition of the Yu’anshan Formation. The Chengjiang biota occurs in strata that appear to have been deposited under an oxygen-depleted water column that may have supported denitrification, as in modern...

  12. Nonbiomineralized carapaces in Cambrian seafloor landscapes (Sirius Passet, Greenland)

    DEFF Research Database (Denmark)

    Mangano, M. Gabriela; Bromley, Richard Granville; Harper, David A. T.


    -caliber structures with dendritic terminations, and annulated burrows are abundant in the Early Cambrian Sirius Basset Lagerstatte (Greenland). Taphonomic controls were partially responsible for the pronounced association of these structures and carapaces, but ecologic conditions are envisioned as playing...

  13. The oldest brachiopods from the lower cambrian of South Australia

    DEFF Research Database (Denmark)

    Topper, Timothy Paul; Holmer, Lars E.; Skovsted, Christian B.


    The morphology and organophosphatic shell structure of the paterinate brachiopod Askepasma is documented using new and previously collected specimens from the lower Cambrian of South Australia. Lack of adequately preserved material has seen the majority of paterinate specimens previously reported...... from South Australia referred to the genus Askepasma and treated under open nomenclature. Large collections of paterinates from the lower Cambrian Wilkawillina, Ajax, and Wirrapowie limestones in the Arrowie Basin, South Australia have prompted redescription of the type species Askepasma toddense...... and the erection of a new species, Askepasma saproconcha sp. nov. Askepasma saproconcha sp. nov. currently represents the oldest known brachiopod from the lower Cambrian successions in South Australia with a FAD in pre-trilobitic (Terreneuvian, Cambrian Stage 2, lower Atdabanian) strata in the basal part...

  14. An Early Cambrian stem polychaete with pygidial cirri (United States)

    Vinther, Jakob; Eibye-Jacobsen, Danny; Harper, David A. T.


    The oldest annelid fossils are polychaetes from the Cambrian Period. They are representatives of the annelid stem group and thus vital in any discussion of how we polarize the evolution of the crown group. Here, we describe a fossil polychaete from the Early Cambrian Sirius Passet fauna, Pygocirrus butyricampum gen. et sp. nov., with structures identified as pygidial cirri, which are recorded for the first time from Cambrian annelids. The body is slender and has biramous parapodia with chaetae organized in laterally oriented bundles. The presence of pygidial cirri is one of the characters that hitherto has defined the annelid crown group, which diversified during the Cambrian–Ordovician transition. The newly described fossil shows that this character had already developed within the total group by the Early Cambrian. PMID:21733871

  15. Primitive soft-bodied cephalopods from the Cambrian. (United States)

    Smith, Martin R; Caron, Jean-Bernard


    The exquisite preservation of soft-bodied animals in Burgess Shale-type deposits provides important clues into the early evolution of body plans that emerged during the Cambrian explosion. Until now, such deposits have remained silent regarding the early evolution of extant molluscan lineages-in particular the cephalopods. Nautiloids, traditionally considered basal within the cephalopods, are generally depicted as evolving from a creeping Cambrian ancestor whose dorsal shell afforded protection and buoyancy. Although nautiloid-like shells occur from the Late Cambrian onwards, the fossil record provides little constraint on this model, or indeed on the early evolution of cephalopods. Here, we reinterpret the problematic Middle Cambrian animal Nectocaris pteryx as a primitive (that is, stem-group), non-mineralized cephalopod, based on new material from the Burgess Shale. Together with Nectocaris, the problematic Lower Cambrian taxa Petalilium and (probably) Vetustovermis form a distinctive clade, Nectocarididae, characterized by an open axial cavity with paired gills, wide lateral fins, a single pair of long, prehensile tentacles, a pair of non-faceted eyes on short stalks, and a large, flexible anterior funnel. This clade extends the cephalopods' fossil record by over 30 million years, and indicates that primitive cephalopods lacked a mineralized shell, were hyperbenthic, and were presumably carnivorous. The presence of a funnel suggests that jet propulsion evolved in cephalopods before the acquisition of a shell. The explosive diversification of mineralized cephalopods in the Ordovician may have an understated Cambrian 'fuse'.

  16. The Bahrain Burial Mound Project

    DEFF Research Database (Denmark)

    Laursen, Steffen; Johansen, Kasper Lambert


    the majority of burial mounds have been removed to make way for roads and housing, and in this process about 8000 mounds have been excavated; of these only c. 265 have been published. In 2006 the Bahrain Directorate for Culture & National Heritage and Moesgaard Museum decided on a collaborative project...... process of linking relevant information to the mounds have been initiated in the course of which excavation data of individual monument is being fed into a relational database. Our preliminary study of the digital maps of the mound cemeteries has revealed an abundance of interesting patterns...... that immediately gave rise to puzzling new questions that will direct the future explorations of the project. Of particular interest is a distinctive new type of elite monuments situated to the south of the so-called Royal Mounds in the centre of the island. The newly discovered type of mounds apparently reflect...

  17. Carbon Sequestration via Wood Burial (United States)

    Zeng, N.


    To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which forest dead wood or old trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It was estimated that the carbon sequestration potential of forest wood harvest and burial is 10GtC y-1 with an uncertainty range of 5-15 GtC y-1. Based on data from North American logging industry, the cost was crudely estimated at $50/tC, significantly lower than the cost for power plant CO2 capture with geological storage, a carbon sequestration technique currently under most serious consideration. The low cost is largely because the CO2 capture is achieved at little cost by the natural process of photosynthesis. The technique is low tech, distributed, safe and can be stopped or reversed at any time. The relatively low cost may soon be competitive enough for large-scale implementation in a world-wide carbon trading market. In tropical regions with ongoing deforestation, wood burial instead of burning will immediately reduce that portion of the anthropogenic CO2 emission.

  18. Sediment Burial Intolerance of Marine Macroinvertebrates.

    Directory of Open Access Journals (Sweden)

    Vicki J Hendrick

    Full Text Available The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (Ophiura ophiura, the queen scallop (Aequipecten opercularis and the sea squirt (Ciona intestinalis were all highly intolerant to burial whilst the green urchin (Psammichinus miliaris and the anemone (Sagartiogeton laceratus, showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (Sabellaria spinulosa. With the exception of C. intestinalis, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For C. intestinalis depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed O. ophiura emerged most frequently, followed by P. miliaris. The former emerged most frequently from the medium and fine sediments whereas P. miliaris emerged more frequently from coarse sediment. Both A. opercularis and S. laceratus showed similar emergence responses over time, with A. opercularis emerging more frequently under coarse sediments. The frequency of emergence of S. laceratus increased with progressively finer sediment and C. intestinalis did not emerge from burial irrespective of sediment fraction or depth. Finally

  19. Sediment Burial Intolerance of Marine Macroinvertebrates. (United States)

    Hendrick, Vicki J; Hutchison, Zoë L; Last, Kim S


    The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (Ophiura ophiura), the queen scallop (Aequipecten opercularis) and the sea squirt (Ciona intestinalis) were all highly intolerant to burial whilst the green urchin (Psammichinus miliaris) and the anemone (Sagartiogeton laceratus), showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (Sabellaria spinulosa). With the exception of C. intestinalis, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For C. intestinalis depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed O. ophiura emerged most frequently, followed by P. miliaris. The former emerged most frequently from the medium and fine sediments whereas P. miliaris emerged more frequently from coarse sediment. Both A. opercularis and S. laceratus showed similar emergence responses over time, with A. opercularis emerging more frequently under coarse sediments. The frequency of emergence of S. laceratus increased with progressively finer sediment and C. intestinalis did not emerge from burial irrespective of sediment fraction or depth. Finally, and perhaps

  20. Early Cambrian oxygen minimum zone-like conditions at Chengjiang (United States)

    Hammarlund, Emma U.; Gaines, Robert R.; Prokopenko, Maria G.; Qi, Changshi; Hou, Xian-Guang; Canfield, Donald E.


    The early Cambrian succession at Chengjiang contains the most diverse Cambrian fossil assemblage yet described, and contributes significantly to our understanding of the diversification of metazoans in the Cambrian ;explosion;. The Cambrian Period occupies a transitional episode of global ocean chemistry, following the oxygenation of the surface ocean and of shallow marine environments during the Ediacaran Period, but prior to the establishment of a predominantly oxygenated deep ocean in the mid-Paleozoic. Despite recent attention, a detailed understanding of the chemical conditions that prevailed in early Cambrian marine settings and the relationship of those conditions to early metazoan ecosystems is still emerging. Here, we report multi-proxy geochemical data from two drill cores through the early Cambrian (Series 2) Yu'anshan Formation of Yunnan, China. Results reveal dynamic water-column chemistry within the succession, which progressively shifted from euxinic to oxic conditions during deposition of the Yu'anshan Formation. The Chengjiang biota occurs in strata that appear to have been deposited under an oxygen-depleted water column that may have supported denitrification, as in modern oxygen-minimum zones. The oxygenated benthic environments in which the Chengjiang biota thrived were proximal to, but sharply separated from, the open ocean by a persistent anoxic water mass that occupied a portion of the outer shelf. Oxygen depletion in the lower water column developed dynamically in response to nutrient availability and possibly at lower thresholds of productivity due to lower atmospheric oxygen concentrations in Cambrian. These findings suggest that the frequent development of oxygen-limiting conditions in continental margin settings provided an environmental barrier that may have affected biogeographic, ecological and evolutionary development of early metazoan communities.

  1. Diagenetic and thermal evolution of Rotliegend sandstones from onshore Schleswig-Holstein

    Energy Technology Data Exchange (ETDEWEB)

    Schoener, R.; Gaupp, R. [Universitaet Jena, (Germany). Institut fuer Geowissenschaften


    The investigation of diagenetic processes in deeply buried Rotliegend sandstones, which are a major target of hydrocarbon exploration, is an important tool to understand fluid evolution and migration during basin subsidence. In the area of Schleswig-Holstein at the northern margin of the Central European Basin (CEB), relatively few deep wells have been drilled in past, compared to the intensely explored southern part of the basin. e.g. in the region north of Hannover. Concordantly, little is known about Rotliegend diagenesis in the subsurface of northernmost Germany. To examine the diagenetic evolution of Rotliegend sandstones in this area, core material from three deep exploration wells, which have been released within the DFG research program (SPP) 1135, were investigated in detail with petrographic and geochemical methods. The burial and thermal history was calculated using PetroMod 1D (IES Juelich, version 8). (orig.)

  2. Solid waste burial grounds interim safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Saito, G.H.


    This Interim Safety Analysis document supports the authorization basis for the interim operation and restrictions on interim operations for the near-surface land disposal of solid waste in the Solid Waste Burial Grounds. The Solid Waste Burial Grounds Interim Safety Basis supports the upgrade progress for the safety analysis report and the technical safety requirements for the operations in the Solid Waste Burial Grounds. Accident safety analysis scenarios have been analyzed based on the significant events identified in the preliminary hazards analysis. The interim safety analysis provides an evaluation of the operations in the Solid Waste Burial Grounds to determine if the radiological and hazardous material exposures will be acceptable from an overall health and safety standpoint to the worker, the onsite personnel, the public, and the environment.

  3. New reticulosan sponges from the middle Cambrian of Sonora, Mexico

    Directory of Open Access Journals (Sweden)

    Matilde Sylvia Beresi


    Full Text Available A small assemblage of extremely well-preserved fragments of new sponges has been discovered in calcipelites of the middle Cambrian El Mogallón Formation in the Cerro El Mogallón section, near Arivechi in eastern Sonora, Mexico. The assemblage includes two new reticulosan species referred to Ratcliffespongia arivechensis sp. nov. and Valospongia sonorensis sp. nov., combined with disarticulated remains assigned to Kiwetinokia and additional, currently unidentifiable taxa. The new species represent the first records of these Cambrian genera from Mexico, although they are widely distributed at low latitudes, being previously best known from Utah but extending through Laurentia and South China. This middle Cambrian fauna indicates that there was considerable continuity of the deeper-water hexactinellid sponges between the warm peri-platform of Laurentia and the peri-continental Cambrian platform of Sonora. The new material supports the impression of extremely wide distribution of Cambrian sponge genera, with local diversification at species level within regions, in contrast to much greater generic-level endemism during the Ordovician Period.

  4. Cleanup Verification Package for the 618-2 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    W. S. Thompson


    This cleanup verification package documents completion of remedial action for the 618-2 Burial Ground, also referred to as Solid Waste Burial Ground No. 2; Burial Ground No. 2; 318-2; and Dry Waste Burial Site No. 2. This waste site was used primarily for the disposal of contaminated equipment, materials and laboratory waste from the 300 Area Facilities.

  5. Veterans Benefits: Burial Benefits and National Cemeteries (United States)


    hospital, nursing home, or domiciliary care facility; and (2) a plot allowance for a veteran eligible for burial in a national cemetery who is not... domiciliary care . The VA was permitted to enter into contracts to provide the burial and funeral services for veterans who died in VA facilities...Veterans Affairs (VA) provides a range of benefits and services to veterans who meet certain eligibility rules; benefits include hospital and medical care

  6. Burial effects on bedload tracer transport (United States)

    Wu, Zi; Foufoula-Georgiou, Efi; Parker, Gary; Singh, Arvind; Fu, Xudong; Wang, Guangqian


    The gradual burial of tracer particles during bedload transport is a recently identified physical source of super-diffusion. It remains unclear, however how exactly this burial effect is related to the possible regimes of anomalous diffusion. In this paper we incorporate the mechanism of tracer burial into the active layer formulation for bedload transport, enabling an analytical treatment of the problem. The deduced equation governing the active layer is shown to be an advection-diffusion equation (ADE) with a sink term, and the increase of tracer concentration in the substrate layer underneath is driven by a corresponding source term which corresponds precisely to the sink term of the active layer. The solution for the variance of the tracer plume is analytically determined by calculating the relevant concentration moments based on the solved concentration distribution. It is shown that when substrate burial is accounted for, there will generally be a normal diffusion regime at very short time scales and a sub-diffusion regime at very large time scales. The appearance and characteristics of a super-diffusion regime during intermediate time scales will depend on relations among particle diffusion coefficient, burial frequency, and the virtual streamwise velocity for the tracer plume. This is in contrast to the single normal diffusion regime obtained for bedload transport when the burial process is not considered.

  7. Proterozoic and early Cambrian protists: evidence for accelerating evolutionary tempo (United States)

    Knoll, A. H.


    In rocks of late Paleoproterozoic and Mesoproterozoic age (ca. 1700-1000 million years ago), probable eukaryotic microfossils are widespread and well preserved, but assemblage and global diversities are low and turnover is slow. Near the Mesoproterozoic-Neoproterozoic boundary (1000 million years ago), red, green, and chromophytic algae diversified; molecular phylogenies suggest that this was part of a broader radiation of "higher" eukaryotic phyla. Observed diversity levels for protistan microfossils increased significantly at this time, as did turnover rates. Coincident with the Cambrian radiation of marine invertebrates, protistan microfossils again doubled in diversity and rates of turnover increased by an order of magnitude. Evidently, the Cambrian diversification of animals strongly influenced evolutionary rates, within clades already present in marine communities, implying an important role for ecology in fueling a Cambrian explosion that extends across kingdoms.

  8. Cambrian stalked echinoderms show unexpected plasticity of arm construction. (United States)

    Zamora, S; Smith, A B


    Feeding arms carrying coelomic extensions of the theca are thought to be unique to crinoids among stemmed echinoderms. However, a new two-armed echinoderm from the earliest Middle Cambrian of Spain displays a highly unexpected morphology. X-ray microtomographic analysis of its arms shows they are polyplated in their proximal part with a dorsal series of uniserial elements enclosing a large coelomic lumen. Distally, the arm transforms into the more standard biserial structure of a blastozoan brachiole. Phylogenetic analysis demonstrates that this taxon lies basal to rhombiferans as sister-group to pleurocystitid and glyptocystitid blastozoans, drawing those clades deep into the Cambrian. We demonstrate that Cambrian echinoderms show surprising variability in the way their appendages are constructed, and that the appendages of at least some blastozoans arose as direct outgrowths of the body in much the same way as the arms of crinoids.

  9. Early Cambrian oxygen minimum zone-like conditions at Chengjiang

    DEFF Research Database (Denmark)

    Hammarlund, Emma U.; Gaines, Robert R.; Prokopenko, Maria G.


    in early Cambrian marine settings and the relationship of those conditions to early metazoan ecosystems is still emerging. Here, we report multi-proxy geochemical data from two drill cores through the early Cambrian (Series 2) Yu’anshan Formation of Yunnan, China. Results reveal dynamic water...... oxygen-minimum zones. The oxygenated benthic environments in which the Chengjiang biota thrived were proximal to, but sharply separated from, the open ocean by a persistent anoxic water mass that occupied a portion of the outer shelf. Oxygen depletion in the lower water column developed dynamically...

  10. 38 CFR 3.1610 - Burial in national cemeteries; burial of unclaimed bodies. (United States)


    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Burial in national cemeteries; burial of unclaimed bodies. 3.1610 Section 3.1610 Pensions, Bonuses, and Veterans' Relief... deceased veteran is unclaimed by relatives or friends (see § 3.1603), the Director of the regional office...

  11. Black Weathering of Bentheim and Obernkirchen Sandstone

    NARCIS (Netherlands)

    Nijland, T.G.; Dubelaar, C.W.; Van Hees, R.P.J.; Linden, T.J.M.


    Black weathering of sandstone in monuments is widespread. Some objects owe their name to it, like the Porta Nigra in Trier (Germany). Other than the black gypsum crusts common on limestone, the black weathering layer on sandstone is rather thin and well adherent. Formation of such layers on Bentheim


    African Journals Online (AJOL)

    The Ajali Sandstone is a major clastic formation of Campanian-Maastrichtian age occuring within the Anambra Basin, Southeastern Nigeria. The Sandstones have a high incidence of quartz and feldspar pebbles. Clasts of vein quartz pebbles were selected for morphometric study of decipher the depositional environment of ...

  13. Fossils, molecules and embryos: new perspectives on the Cambrian explosion (United States)

    Valentine, J. W.; Jablonski, D.; Erwin, D. H.


    The Cambrian explosion is named for the geologically sudden appearance of numerous metazoan body plans (many of living phyla) between about 530 and 520 million years ago, only 1.7% of the duration of the fossil record of animals. Earlier indications of metazoans are found in the Neoproterozic; minute trails suggesting bilaterian activity date from about 600 million years ago. Larger and more elaborate fossil burrows appear near 543 million years ago, the beginning of the Cambrian Period. Evidence of metazoan activity in both trace and body fossils then increased during the 13 million years leading to the explosion. All living phyla may have originated by the end of the explosion. Molecular divergences among lineages leading to phyla record speciation events that have been earlier than the origins of the new body plans, which can arise many tens of millions of years after an initial branching. Various attempts to date those branchings by using molecular clocks have disagreed widely. While the timing of the evolution of the developmental systems of living metazoan body plans is still uncertain, the distribution of Hox and other developmental control genes among metazoans indicates that an extensive patterning system was in place prior to the Cambrian. However, it is likely that much genomic repatterning occurred during the Early Cambrian, involving both key control genes and regulators within their downstream cascades, as novel body plans evolved.

  14. Ediacaran and Cambrian stratigraphy in Estonia: an updated review

    Directory of Open Access Journals (Sweden)

    Tõnu Meidla


    Full Text Available Previous late Precambrian and Cambrian correlation charts of Estonia, summarizing the regional stratigraphic nomenclature of the 20th century, date back to 1997. The main aim of this review is updating these charts based on recent advances in the global Precambrian and Cambrian stratigraphy and new data from regions adjacent to Estonia. The term ‘Ediacaran’ is introduced for the latest Precambrian succession in Estonia to replace the formerly used ‘Vendian’. Correlation with the dated sections in adjacent areas suggests that only the latest 7–10 Ma of the Ediacaran is represented in the Estonian succession. The gap between the Ediacaran and Cambrian may be rather substantial. The global fourfold subdivision of the Cambrian System is introduced for Estonia. The lower boundary of Series 2 is drawn at the base of the Sõru Formation and the base of Series 3 slightly above the former lower boundary of the ‘Middle Cambrian’ in the Baltic region, marked by a gap in the Estonian succession. The base of the Furongian is located near the base of the Petseri Formation.

  15. An Ediacaran–Cambrian thermal imprint in Rajasthan, western India ...

    Indian Academy of Sciences (India)

    East Sahara. Congo. Kalahari. Kuunga. Orogen. 570-530 Ma. 570-500 Ma. East. Antarctica. Grenville-age orogens cratons. Neoproterozoic to. Cambrian orogens. Dharwar. Aravalli. Craton. Figure 6. Reconstruction of Gondwanaland in Cambrian–Ordovician time, showing cratonic regions, Grenville-age orogens,.

  16. An Ediacaran–Cambrian thermal imprint in Rajasthan, western India ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 122; Issue 6. An Ediacaran–Cambrian thermal imprint in Rajasthan, western India: Evidence from 40Ar-39Ar geochronology of the Sindreth volcanics. Archisman Sen Kanchan Pande Hetu C Sheth Kamal Kant Sharma Shraboni Sarkar A M Dayal Harish Mistry.

  17. Origin of middle Silurian Keefer sandstone, east-central Appalachian basin

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, S.C.; Textoris, D.A.; Dennison, J.M.


    The Keefer Sandstone of northeastern West Virginia and western Maryland was deposited in back-barrier, barrier-island, and marine shelf environments along a prograding, storm-dominated, mesotidal coastline of probable low wave energy. Back-barrier sediments were deposited in tidal-flat and lagoonal environments. Barrier-island sediments are dominated by cross-bedded sandstones deposited in deep, laterally migrating tidal inlets. Erosion accompanying the passage of a migrating tidal inlet usually resulted in the removal of underyling shoreface and shelf sands, so that tidal-inlet sandstones commonly lie with a markedly erosive contact on subtidal shales of the underlying Rose Hill Formation. Sand was transported to the shelf from the coastline by downwelling, storm-generated currents. Chamosite ooids formed in gently agitated waters immediately below fair-weather wave base. Outcrops to the east, which preserve back-barrier and barrier-island lithofacies, record a single basinward progradation of the shoreline. However, outcrops farther west, which preserve finer grained sandstone, shale, and limestone shelf lithofacies, document four progradational events in stacked coarsening-upward sequences. Each is typically capped by transgressive sandstones, commonly hematite ooid-bearing, which mark episodes of coastal retreat. Retreat occurred through shoreface and nearshore erosion. Chamosite ooids were transported basinward during coastal retreat and altered to hematite prior to burial. Transgressive shelf sands contain abundant coarse sand eroded from tidal-inlet deposits. Deposition of the Keefer was a response to a decrease in rate of eustatic sea level rise, or a decrease in basin subsidence rate. This was followed by deposition of the transgressive basin facies of the Rochester Shale.

  18. Hydrothermal Dissolution of Deeply Buried Cambrian Dolomite Rocks and Porosity Generation: Integrated with Geological Studies and Reactive Transport Modeling in the Tarim Basin, China

    Directory of Open Access Journals (Sweden)

    Wenwen Wei


    Full Text Available The burial dissolution of carbonate rocks has long been an interesting topic of reservoir geologists. Integrated with geological studies and reactive transport modeling, this study investigated the Cambrian dolomites that were buried at depths up to 8408 m and still preserved a large amount of unfilled dissolution vugs from the borehole TS1 in the northern Tarim Basin. Studies indicate that these vugs were formed in association with fault-channeled hydrothermal fluids from greater depth through “retrograde dissolution” as the fluid temperature dropped during upward migration. The reactive transport modeling results suggest an important control of the vertical permeability of wall-rock on fluid and temperature patterns which, in turn, would control the spatial distribution of dissolving-originated porosity. The hydrothermal dissolution mainly occurred in dolomite wall-rocks with higher vertical permeability (extensive development of tensional fractures and connected pore spaces, producing additional dissolved porosity there during deep burial. This study implicates the importance of multidisciplinary approaches for understanding the burial/hydrothermal dissolution of dolomite rocks and predicting favourable deep/ultradeep carbonate reservoirs.

  19. Reconstructing the Avalon continent: Marginal to inner platform transition in the Cambrian of southern New Brunswick (United States)

    Landing, E.


    A west to east, marginal to inner Avalonian platform transition, comparable to that in southeast Newfoundland and southern Britain, is present in the Cambrian of southern New Brunswick. The Saint John - Caton's Island - Hanford Brook area lay on the marginal platform, and its thick, uppermost Precambrian - lower Lower Cambrian is unconformably overlain by trilobite-bearing, upper Lower Cambrian. An inner platform remnant is preserved in the Cradle Brook outlier 60 km northeast of Saint John. In contrast to the marginal platform sequences, the Cradle Brook outlier has a very thin lower Lower Cambrian and has middle Lower Cambrian strata (Bonavista Group) not present on the marginal platform. The Cradle Brook Lower Cambrian closely resembles inner platform successions in eastern Massachusetts and Trinity and Placentia bays, southeast Newfoundland. A limestone with Camenella baltica Zone fossils on Cradle Brook seems to be the peritidal limestone cap of the subtrilobitic Lower Cambrian known in Avalonian North America (Fosters Point Formation) and England (Home Farm Member).

  20. Geochemical interpretation of the Precambrian basement and overlying Cambrian sandstone on Bornholm, Denmark: Implications for the weathering history

    DEFF Research Database (Denmark)

    Zhou, Lingli; Friis, Henrik; Yang, Tian


    A geochemical study of the Precambrian basement granites from the Borggård borehole on Bornholm, Denmark, suggests that the granites were moderately weathered (Chemical Index of Alteration-CIA=66–71) during subaerial exposure in a humid climate. The microcline iswell preserved,whereas plagioclase...... the weathered basement granite from the Borggård borehole and regional granitoids on Bornholm, constrains the Svaneke Granite as the original basement lithology. A tau (τ) mass transportmodel (assuming immobile Ti) was applied to quantify the mass transfer during weathering of the basement granite. The results...... to the intermediate group of the regional granitoids on Bornholm. The source materials for the AKM (CIA = 71–72, PIA=94–96), the GadebyMember in the Borggård borehole (CIA=52–69, PIA=56–99) and an outcrop in Nexø, eastern Bornholm (CIA = 52–66, PIA = 61–96), have endured similar degrees of weak to moderate weathering...

  1. Compilation and network analyses of cambrian food webs.

    Directory of Open Access Journals (Sweden)

    Jennifer A Dunne


    Full Text Available A rich body of empirically grounded theory has developed about food webs--the networks of feeding relationships among species within habitats. However, detailed food-web data and analyses are lacking for ancient ecosystems, largely because of the low resolution of taxa coupled with uncertain and incomplete information about feeding interactions. These impediments appear insurmountable for most fossil assemblages; however, a few assemblages with excellent soft-body preservation across trophic levels are candidates for food-web data compilation and topological analysis. Here we present plausible, detailed food webs for the Chengjiang and Burgess Shale assemblages from the Cambrian Period. Analyses of degree distributions and other structural network properties, including sensitivity analyses of the effects of uncertainty associated with Cambrian diet designations, suggest that these early Paleozoic communities share remarkably similar topology with modern food webs. Observed regularities reflect a systematic dependence of structure on the numbers of taxa and links in a web. Most aspects of Cambrian food-web structure are well-characterized by a simple "niche model," which was developed for modern food webs and takes into account this scale dependence. However, a few aspects of topology differ between the ancient and recent webs: longer path lengths between species and more species in feeding loops in the earlier Chengjiang web, and higher variability in the number of links per species for both Cambrian webs. Our results are relatively insensitive to the exclusion of low-certainty or random links. The many similarities between Cambrian and recent food webs point toward surprisingly strong and enduring constraints on the organization of complex feeding interactions among metazoan species. The few differences could reflect a transition to more strongly integrated and constrained trophic organization within ecosystems following the rapid

  2. The Management of Risk by Burial Societies in South Africa ...

    African Journals Online (AJOL)

    It considers members\\' perceptions of the risks faced by the burial societies themselves. It explores the ways in which burial societies develop community and establish trust. It investigates the procedures that have been developed by burial societies, on the basis of the trust so established, for the management of their risks.

  3. 38 CFR 38.629 - Outer Burial Receptacle Allowance. (United States)


    ... Allowance. 38.629 Section 38.629 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Allowance. (a) Definitions—Outer burial receptacle. For purposes of this section, an outer burial receptacle... section provides for payment of a monetary allowance for an outer burial receptacle for any interment in a...

  4. Experimental strain analysis of Clarens Sandstone colonised by endolithic lichens

    Directory of Open Access Journals (Sweden)

    D. Wessels


    Full Text Available Endolithic lichens occur commonly on Clarens Sandstone in South Africa, where they significantly contribute to the weathering of sandstone by means of mechanical and chemical weathering processes. This preliminary investigation reports on the success- ful use of strain gauges in detecting strain differences between sandstone without epilithic lichens and sandstone colonised by the euendolithic lichen Lecidea aff. sarcogynoides Korb. Mechanical weathering, expressed as strain changes, in Clarens Sandstone was studied during the transition from relatively dry winter to wet summer conditions. Daily weathering of sandstone due to thermal expansion and contraction of colonised and uncolonised sandstone could be shown. Our results show that liquid water in sandstone enhances the mechanical weathering of uncolonised Clarens Sandstone while water in the gaseous phase enhances mechanical weathering of sandstone by euendolithic lichens.

  5. Tropical shoreline ice in the late Cambrian: Implications for earth's climate between the Cambrian Explosion and the Great Ordovician Biodiversification Event (United States)

    Runkel, Anthony C.; MacKey, T.J.; Cowan, Clinton A.; Fox, David L.


    Middle to late Cambrian time (ca. 513 to 488 Ma) is characterized by an unstable plateau in biodiversity, when depauperate shelf faunas suffered repeated extinctions. This poorly understood interval separates the Cambrian Explosion from the Great Ordovician Biodiversification Event and is generally regarded as a time of sustained greenhouse conditions. We present evidence that suggests a drastically different climate during this enigmatic interval: Features indicative of meteoric ice are well preserved in late Cambrian equatorial beach deposits that correspond to one of the shelf extinction events. Thus, the middle to late Cambrian Earth was at least episodically cold and might best be considered a muted analogue to the environmental extremes that characterized the Proterozoic, even though cooling in the two periods may have occurred in response to different triggers. Such later Cambrian conditions may have significantly impacted evolution preceding the Ordovician radiation.

  6. Upper Cambrian chitons (Mollusca, polyplacophora) from Missouri, USA (United States)

    Pojeta, J.; Vendrasco, M.J.; Darrough, G.


    Numerous new specimens reveal a greater presence of chitons in Upper Cambrian rocks than previously suspected. Evidence is presented showing that the chiton esthete sensory system is present in all chiton species in this study at the very beginning of the known polyplacophoran fossil record. The stratigraphic occurrences and paleobiogeography of Late Cambrian chitons are documented. The 14 previously-named families of Cambrian and Ordovician chitons are reviewed and analyzed. Aulochitonidae n. fam. is defined, based on Aulochiton n. gen.; A. sannerae n. sp. is also defined. The long misunderstood family Preacanthochitonidae and its type genus Preacanthochiton Bergenhayn, 1960, are placed in synonymy with Mattheviidae and Chelodes Davidson & King, 1874, respectively; Eochelodes Marek, 1962, also is placed in synonymy with Chelodes, and Elongata Stinchcomb & Darrough, 1995, is placed in synonymy with Hemithecella Ulrich & Bridge, 1941. At the species level, H. elongata Stinchcomb & Darrough, 1995, and Elongata perplexa Stinchcomb & Darrough, 1995, are placed in synonymy with H. eminensis Stinchcomb & Darrough, 1995. The Ordovician species H. abrupta Stinchcomb & Darrough, 1995, is transferred to the genus Chelodes as C. abrupta (Stinchcomb & Darrough, 1995). The Ordovician species Preacanthochiton baueri Hoare & Pojeta, 2006, is transferred to the genus Helminthochiton as H. ? baueri (Hoare & Pojeta, 2006). The Ordovician species H. marginatus Hoare & Pojeta, 2006, is transferred to the genus Litochiton as L. marginatus (Hoare & Pojeta, 2006). Matthevia walcotti Runnegar, Pojeta, Taylor, & Collins, 1979, is treated as a synonym of Hemithecella expansa Ulrich & Bridge, 1941. In addition, other multivalved Cambrian mollusks are discussed; within this group, Dycheiidae n. fam. is defined, as well as Paradycheia dorisae n. gen. and n. sp. Cladistic analysis indicates a close relationship among the genera here assigned to the Mattheviidae, and between Echinochiton Pojeta

  7. Early Cambrian pentamerous cubozoan embryos from South China.

    Directory of Open Access Journals (Sweden)

    Jian Han

    Full Text Available BACKGROUND: Extant cubozoans are voracious predators characterized by their square shape, four evenly spaced outstretched tentacles and well-developed eyes. A few cubozoan fossils are known from the Middle Cambrian Marjum Formation of Utah and the well-known Carboniferous Mazon Creek Formation of Illinois. Undisputed cubozoan fossils were previously unknown from the early Cambrian; by that time probably all representatives of the living marine phyla, especially those of basal animals, should have evolved. METHODS: Microscopic fossils were recovered from a phosphatic limestone in the Lower Cambrian Kuanchuanpu Formation of South China using traditional acetic-acid maceration. Seven of the pre-hatched pentamerous cubozoan embryos, each of which bears five pairs of subumbrellar tentacle buds, were analyzed in detail through computed microtomography (Micro-CT and scanning electron microscopy (SEM without coating. RESULTS: The figured microscopic fossils are unequivocal pre-hatching embryos based on their spherical fertilization envelope and the enclosed soft-tissue that has preserved key anatomical features arranged in perfect pentaradial symmetry, allowing detailed comparison with modern cnidarians, especially medusozoans. A combination of features, such as the claustrum, gonad-lamella, suspensorium and velarium suspended by the frenula, occur exclusively in the gastrovascular system of extant cubozoans, indicating a cubozoan affinity for these fossils. Additionally, the interior anatomy of these embryonic cubozoan fossils unprecedentedly exhibits the development of many new septum-derived lamellae and well-partitioned gastric pockets unknown in living cubozoans, implying that ancestral cubozoans had already evolved highly specialized structures displaying unexpected complexity at the dawn of the Cambrian. The well-developed endodermic lamellae and gastric pockets developed in the late embryonic stages of these cubozoan fossils are comparable with

  8. "Sydney sandstone": Heritage Stone from Australia (United States)

    Cooper, Barry; Kramar, Sabina


    Sydney is Australia's oldest city being founded in 1788. The city was fortunate to be established on an extensive and a relatively undeformed layer of lithified quartz sandstone of Triassic age that has proved to be an ideal building stone. The stone has been long identified by geologists as the Hawkesbury Sandstone. On the other hand the term "Sydney sandstone" has also been widely used over a long period, even to the extent of being utilised as the title of published books, so its formal designation as a heritage stone will immediately formalise this term. The oldest international usage is believed to be its use in the construction of the Stone Store at Kerikeri, New Zealand (1832-1836). In the late 19th century, public buildings such as hospitals, court houses as well as the prominent Sydney Town Hall, Sydney General Post Office, Art Gallery of New South Wales, State Library of New South Wales as well as numerous schools, churches, office building buildings, University, hotels, houses, retaining walls were all constructed using Sydney sandstone. Innumerable sculptures utilising the gold-coloured stone also embellished the city ranging from decorative friezes and capitals on building to significant monuments. Also in the late 19th and early 20th century, Sydney sandstone was used for major construction in most other major Australian cities especially Melbourne, Adelaide and Brisbane to the extent that complaints were expressed that suitable local stone materials were being neglected. Quarrying of Sydney sandstone continues today. In 2000 it was recorded noted that there were 33 significant operating Sydney sandstone quarries including aggregate and dimension stone operations. In addition sandstone continues to be sourced today from construction sites across the city area. Today major dimension stone producers (eg Gosford Quarries) sell Sydney sandstone not only into the Sydney market but also on national and international markets as cladding and paving products

  9. Recognition of a fluvial facies in the Pacoota Sandstone and its implications for petroleum exploration (United States)

    Deckelman, James A.

    A previously unrecognized fluvial facies is present in the Late Cambrian-Early Ordovician Pacoota Sandstone in the north-central and northwestern parts of the Amadeus Basin. This facies forms the base of the P3 unit and correlates directly with the primary oil and gas producing interval in the Pacoota Sandstone at the Mereenie Field. In order to distinguish this facies from overlying facies in the P3, it is proposed that the P3 be divided into a lower dominantly fluvial unit, the P3B, and an upper estuarine and shoreface unit, the P3A. Both units can be mapped for hundreds of kilometers at the surface and in the subsurface throughout the Mereenie Field and adjacent areas. The P3B is interpreted as a deposit that accumulated in a dominantly fluvial environment on the basis of: its locally erosional lower bounding surface; the absence of body fossils and ichnofossils; the lobate, wedge-shaped geometry of the unit; the subarkosic composition of the sandstone; the presence of pebble and cobble conflomerate; abundant early syngenetic hematite; abundant trough cross-sets up to 1.35 m thick; overturned cross-laminae; relatively abundant asymmetrical ripple marks; contorted stratification; beds in excess of 1 m in thickness; and its unimodal paleocurrent distribution. The P3B grades conformably into overlying estuarine and shoreface sediments of the P3A. Anagentic silicification is the most significant diagenetic event affecting the present lateral distribution of primary porosity in the P3B unit. Because the extent of anagenetic silificiation decreases southward, the potential for preservation of primary porosity is greatest near the southern depositional limit of the unit. Secondary porosity in the P3B formed by the dissolution of feldspar. Because the abundance of feldspar is inversely related to grainsize which decreases to the southeast, the potential for development of secondary porosity is greatest near the southeastern depositional limit of the unit.

  10. Tiny sea anemone from the Lower Cambrian of China.

    Directory of Open Access Journals (Sweden)

    Jian Han

    Full Text Available BACKGROUND: Abundant fossils from the Ediacaran and Cambrian showing cnidarian grade grossly suggest that cnidarian diversification occurred earlier than that of other eumetazoans. However, fossils of possible soft-bodied polyps are scanty and modern corals are dated back only to the Middle Triassic, although molecular phylogenetic results support the idea that anthozoans represent the first major branch of the Cnidaria. Because of difficulties in taxonomic assignments owing to imperfect preservation of fossil cnidarian candidates, little is known about forms ancestral to those of living groups. METHODS AND FINDINGS: We have analyzed the soft-bodied polypoid microfossils Eolympia pediculata gen. et sp. nov. from the lowest Cambrian Kuanchuanpu Formation in southern China by scanning electron microscopy and computer-aided microtomography after isolating fossils from sedimentary rocks by acetic acid maceration. The fossils, about a half mm in body size, are preserved with 18 mesenteries including directives bilaterally arranged, 18 tentacles and a stalk-like pedicle. The pedicle suggests a sexual life cycle, while asexual reproduction by transverse fission also is inferred by circumferential grooves on the body column. CONCLUSIONS: The features found in the present fossils fall within the morphological spectrum of modern Hexacorallia excluding Ceriantharia, and thus Eolympia pediculata could be a stem member for this group. The fossils also demonstrate that basic features characterizing modern hexacorallians such as bilateral symmetry and the reproductive system have deep roots in the Early Cambrian.

  11. Minerals in the gut: scoping a Cambrian digestive system (United States)

    Strang, K. M.; Armstrong, H. A.; Harper, D. A. T.


    The Sirius Passet Lagerstätte of North Greenland contains the first exceptionally preserved mat-ground community of the Cambrian, dominated, in terms of abundance, by trilobites but particularly characterized by iconic arthropods and lobopods, some also occurring in the Burgess shale. High-resolution photography, scanning electron imaging and elemental mapping have been carried out on a variety of specimens of the non-mineralized arthropod Campanamuta mantonae (Budd 2011 J. Syst. Palaeontol. 9, 217-260 (doi:10.1080/14772019.2010.492644)) which has three-dimensional gut and muscle preservation. Results show that the guts contain a high concentration of calcium phosphate (approximating to the mineral francolite), whereas the adjacent muscles are silicified. This indicates a unique, tissue-specific taphonomy for this Cambrian taxon. We hypothesize that the precipitation of calcium phosphate in the guts occurs rapidly after death by `crystal seed' processes in suboxic, slightly acidic conditions; critically, the gut wall remained intact during precipitation. We postulate that the calcium phosphate was derived from ingested cellular material. Silicification of the muscles followed as the localized water chemistry became saturated in silica, high in Fe2+, and low in oxygen and sulfate. We document here the unique occurrence of two distinct but mechanistically similar taphonomic pathways within a diverse suite of possibilities in an Early Cambrian Lagerstätte.

  12. Evolution of animal behaviour in the Ediacaran-Cambrian transition (United States)

    Kenchington, Charlotte; McIlroy, Duncan


    The transition from the Ediacaran to the Cambrian ( 541 million years ago) marks a fundamental leap in the evolution of life: the evolution of complex animal behaviour, the decline in the microbial mats that characterised the Neoproterozoic and a drastic change in the chemistry of the sediment-water interface. Disturbance is well known as a controlling factor in structuring modern communities. By combining detailed petrographic analysis with data on sedimentology, burrow densities, and ichnodiversity of the basal Cambrian stratotype we are able to place the evolution of animal behaviour recorded in these successions into an improved palaeoenvironmental context. Additionally, Ediacaran-Cambrian ichnofabrics are found to be comparable to experimentally produced ones created by simple ecdysozoans and lophotrochozoans collected from the dysoxic sediments of the Bonne Bay fjords of western Newfoundland. Using multivariate statistical analyses, it is possible to identify and quantify any correlation between palaeoenviromental, ichnological and matground characteristics. This will create improved understanding of the interplay between biological and abiological processes during the evolution of complex animal behaviour in a palaeoenvironmental context.

  13. 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.


    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)

  14. Facies-controlled fluid migration patterns and subsequent reservoir collapse by depressurization - the Entrada Sandstone, Utah (United States)

    Sundal, A.; Skurtveit, E.; Midtkandal, I.; Hope, I.; Larsen, E.; Kristensen, R. S.; Braathen, A.


    The thick and laterally extensive Middle Jurassic Entrada Sandstone forms a regionally significant reservoir both in the subsurface and as outcrops in Utah. Individual layers of fluvial sandstone within otherwise fine-grained aeolian dunes and silty inter-dune deposits of the Entrada Earthy Member are of particular interest as CO2 reservoir analogs to study injectivity, reservoir-caprock interaction and bypass systems. Detailed mapping of facies and deformation structures, including petrographic studies and core plug tests, show significant rock property contrasts between layers of different sedimentary facies. Beds representing fluvial facies appear as white, medium-grained, well-sorted and cross-stratified sandstone, displaying high porosity, high micro-scale permeability, low tensile strength, and low seismic velocity. Subsequent to deposition, these beds were structurally deformed and contain a dense network of deformation bands, especially in proximity to faults and injectites. Over- and underlying low-permeability layers of inter-dune aeolian facies contain none or few deformation bands, display significantly higher rock strengths and high seismic velocities compared to the fluvial inter-beds. Permeable units between low-permeability layers are prone to become over-pressured during burial, and the establishment of fluid escape routes during regional tectonic events may have caused depressurization and selective collapse of weak layers. Through-cutting, vertical sand pipes display large clasts of stratified sandstone suspended in remobilized sand matrix, and may have served as permeable fluid conduits and pressure vents before becoming preferentially cemented and plugged. Bleached zones around faults and fractures throughout the succession indicate leakage and migration of reducing fluids. The fluvial beds are porous and would appear in wireline logs and seismic profiles as excellent reservoirs; whereas due to dense populations of deformation bands they may in

  15. Antarctica, supercontinents and the palaeogeography of the Cambrian 'explosion' (United States)

    Dalziel, Ian


    Laurentia is bordered by latest Precambrian-Cambrian rifted margins and must therefore have been located within a Precambrian supercontinent. Geochronologic and geochemical evidence indicates that it was attached to parts of the East Antarctic craton within the Rodinian supercontinent in the late Mesoproterozoic. The Mawson craton of Antarctica rifted from the proto-Pacific margin of Laurentia during the Neooproterozoic, colliding with the present 'southern cone' of Laurentia at ~600 Ma along the Shackleton Range suture zone as Gondwana and Laurentia amalgamated to form the ephemeral Pannotia supercontinental assembly at the end of the Precambrian. The abrupt appearance of almost all animal phyla in the fossil record is often colloquially referred to as the Cambrian 'explosion' of life on Earth. It is also named 'Darwin's dilemma,' as he appreciated that this seemingly mysterious event posed a major problem for his theory of evolution by natural selection. It coincided with a time of major marine transgression over all the continents. Although the metazoan 'explosion' is now seen as more protracted than formerly recognized, it is still regarded one of the most critical events in the history of the biosphere. One of the most striking aspects of the earliest Cambrian fossils is geographic differentiation. In particular, the first benthic trilobite faunas on Laurentia, ancestral North America, and the newly amalgamated southern supercontinent of Gondwana are distinctly different. This has led to the suggestion of an unknown vicariant event intervening between an ancestral trilobite clade and higher members that are represented in the fossil record, possibly one related to the breakup of a supercontinent. Igneous rocks along the Panthalassic margin of Gondwana, including South America, southernmost Africa and the Ellsworth-Whitmore crustal block of Antarctica, and along the proto-Appalachian margin of Laurentia indicate that final separation of Laurentia from

  16. The disappearance of European smiths' burials

    Czech Academy of Sciences Publication Activity Database

    Ježek, Martin


    Roč. 25, č. 1 (2015), s. 121-143 ISSN 0959-7743 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M300021203 Institutional support: RVO:67985912 Keywords : elite * burial * forging tools * symbolic * ritual * prehistory * Early Middle Ages * Marxism-Leninism Subject RIV: AC - Archeology, Anthropology, Ethnology

  17. Control of Cambrian evaporites on fracturing in fault-related anticlines in the Zagros fold-and-thrust belt (United States)

    Carminati, Eugenio; Aldega, Luca; Bigi, Sabina; Corrado, Sveva; D'Ambrogi, Chiara; Mohammadi, Peyman; Shaban, Ali; Sherkati, Shahram


    Orientation and distribution of fractures in the Oligocene-Early Miocene Asmari Formation (a major reservoir rock of the Zagros petroleum system) were investigated in two anticlines of the Zagros fold-and-thrust belt. The Sim and Kuh-e-Asmari anticlines developed in the areas of the Zagros characterized by the occurrence and absence of Cambrian evaporites at the bottom of the stratigraphic pile, respectively. The aim was to outline major differences in terms of fracture spacing and saturation. Organic matter maturity and clay minerals-based geothermometers suggest that the depth of deformation for the top of the Asmari Formation in the Kuh-e-Asmari anticline was in the range of 1.5-2.7 km assuming a geothermal gradient of 22.5 °C/km. The Asmari Formation in the Sim anticline probably experienced a slightly deeper sedimentary burial (maximum 3 km) with a geothermal gradient of 20 °C/km. The spacing of fractures is generally 2-3 times larger (i.e., strain accommodated by fracturing is smaller) in the Sim anticline than in the Kuh-e-Asmari anticline. This is consistent with regional geological studies, analogue, and numerical models that suggest that thrust faults geometry and related folds are markedly different in the absence or presence of a weak decòllement (evaporites). The larger spacing in the Sim anticline is also consistent with higher temperature predicted for the Asmari Formation in this area. By contrast, the orientation of fractures with respect to the fold axes is the same in both anticlines. The fracture systems are rather immature in both anticlines. The amount and density of fractures in the twofolds are controlled by regional (occurrence/absence of salt and probably different burial), rather than local features (fold geometry).

  18. Some aspects of lithological and exogenic control of sandstone morphology, the Świętokrzyskie (Holy Cross) Mts. case study, Poland (United States)

    Urban, Jan; Górnik, Marek


    Various morphologies of cliffs built of different quartzose rocks in the Świętokrzyskie (Holy Cross) Mts. (upland region, central Poland) - from Cambrian quartzites and Devonian quartzitic sandstones to Triassic and Jurassic porous sandstones - were described in order to examine the constraints of their lithological and spatial occurrence. The quantitative study of the occurrence of these morphologies on cliffs makes it possible to distinguish two principal groups of morphologies: angular relief produced by rock splitting (crumbling), typical of quartzites indurated in silica and of open porosity less than 1.5%, and morphologies developed due to granular disintegration and exfoliation of sandstones of open porosity higher than 1.5%. Among the relief types of this second group, morphology reflecting sedimentary and diagenetic structures as well as smooth surfaces are the most common and are referred to sandstones of a wide range of porosity, whereas honeycombs and surfaces suffering fast granular decay and scaling are characteristic of rocks of specific porosity (respectively: 5-8% and 3.5-8%). The occurrence of honeycombs on rock surfaces is also conditioned by exogenic factors: sun, wind and rain, since this morphology tends to occur on cliffs with aspects ranging from south-east, through south, to west-north-west.

  19. Disparity, decimation and the Cambrian "explosion": comparison of early Cambrian and Present faunal communities with emphasis on velvet worms (Onychophora

    Directory of Open Access Journals (Sweden)

    Julián Monge-Nájera


    Full Text Available The controversy about a Cambrian "explosion" of morphological disparity (followed by decimation, cladogenesis and fossilization is of central importance for the history of life. This paper revisits the controversy (with emphasis in onychophorans, which include emblematic organisms such as Hallucigenia, presents new data about the Chengjiang (Cambrian of China faunal community and compares it and the Burgess Shale (Cambrian of Canada with an ecologically similar but modern tropical marine site where onychophorans are absent, and with a modern neotropical terrestrial onychophoran community. Biovolume was estimated from material collected in Costa Rica and morphometric measurements were made on enlarged images of fossils. Cambrian tropical mudflats were characterized by the adaptive radiation of two contrasting groups: the vagile arthropods and the sessile poriferans. Arthropods were later replaced as the dominant benthic taxon by polychaetes. Vagility and the exoskeleton may explain the success of arthropods from the Cambrian to the modern marine and terrestrial communities, both in population and biovolume. Food ecological displacement was apparent in the B. Shale, but not in Chengjiang or the terrestrial community. When only hard parts were preserved, marine and terrestrial fossil deposits of tropical origin are even less representative than deposits produced by temperate taxa, Chengjiang being an exception. Nutrient limitations might explain why deposit feeding is less important in terrestrial onychophoran communities, where carnivory, scavenging and omnivory (associated with high motility and life over the substrate became more important. Fossil morphometry supports the interpretation of "lobopod animals" as onychophorans, whose abundance in Chengjiang was equal to their abundance in modern communities. The extinction of marine onychophorans may reflect domination of the infaunal habitat by polychaetes. We conclude that (1 a mature ecological

  20. Disparity, decimation and the Cambrian "explosion": comparison of early Cambrian and Present faunal communities with emphasis on velvet worms (Onychophora

    Directory of Open Access Journals (Sweden)

    Julián Monge-Nájera


    Full Text Available The controversy about a Cambrian "explosion" of morphological disparity (followed by decimation, cladogenesis and fossilization is of central importance for the history of life. This paper revisits the controversy (with emphasis in onychophorans, which include emblematic organisms such as Hallucigenia, presents new data about the Chengjiang (Cambrian of China faunal community and compares it and the Burgess Shale (Cambrian of Canada with an ecologically similar but modern tropical marine site where onychophorans are absent, and with a modern neotropical terrestrial onychophoran community. Biovolume was estimated from material collected in Costa Rica and morphometric measurements were made on enlarged images of fossils. Cambrian tropical mudflats were characterized by the adaptive radiation of two contrasting groups: the vagile arthropods and the sessile poriferans. Arthropods were later replaced as the dominant benthic taxon by polychaetes. Vagility and the exoskeleton may explain the success of arthropods from the Cambrian to the modern marine and terrestrial communities, both in population and biovolume. Food ecological displacement was apparent in the B. Shale, but not in Chengjiang or the terrestrial community. When only hard parts were preserved, marine and terrestrial fossil deposits of tropical origin are even less representative than deposits produced by temperate taxa, Chengjiang being an exception. Nutrient limitations might explain why deposit feeding is less important in terrestrial onychophoran communities, where carnivory, scavenging and omnivory (associated with high motility and life over the substrate became more important. Fossil morphometry supports the interpretation of "lobopod animals" as onychophorans, whose abundance in Chengjiang was equal to their abundance in modern communities. The extinction of marine onychophorans may reflect domination of the infaunal habitat by polychaetes. We conclude that (1 a mature ecological

  1. Moulting in the lobopodian Onychodictyon from the lower Cambrian of Greenland

    DEFF Research Database (Denmark)

    Topper, Timothy Paul; Skovsted, Christian B.; Peel, John S.


    A number of lobopodian taxa from the Cambrian display pairs of sclerotized plates symmetrically positioned along the dorsum of the animal, predominantly above the walking appendages. Most genera were described from complete body fossils exquisitely preserved in the famous Cambrian Lagerstatten, b...

  2. Clay squirt: Local flow dispersion in shale-bearing sandstones

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne; Fabricius, Ida Lykke


    Dispersion of elastic-wave velocity is common in sandstone and larger in shaly sandstone than in clean sandstone. Dispersion in fluid-saturated shaly sandstone often exceeds the level expected from the stress-dependent elastic moduli of dry sandstone. The large dispersion has been coined clay...... squirt and is proposed to originate from a pressure gradient between the clay microporosity and the effective porosity. We have formulated a simple model that quantifies the clay-squirt effect on bulk moduli of sandstone with homogeneously distributed shale laminae or dispersed shale. The model...... predictions were compared with the literature data. For sandstones with dispersed shale, agreement was found, whereas other sandstones have larger fluid-saturated bulk modulus, possibly due to partially load-bearing shales or heterogeneous shale distribution. The data that agree with the clay-squirt model...

  3. Cleanup Verification Package for the 618-3 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    M. J. Appel


    This cleanup verification package documents completion of remedial action for the 618-3 Solid Waste Burial Ground, also referred to as Burial Ground Number 3 and the Dry Waste Burial Ground Number 3. During its period of operation, the 618-3 site was used to dispose of uranium-contaminated construction debris from the 311 Building and construction/demolition debris from remodeling of the 313, 303-J and 303-K Buildings.

  4. Cleanup Verification Package for the 618-8 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    M. J. Appel


    This cleanup verification package documents completion of remedial action for the 618-8 Burial Ground, also referred to as the Solid Waste Burial Ground No. 8, 318-8, and the Early Solid Waste Burial Ground. During its period of operation, the 618-8 site is speculated to have been used to bury uranium-contaminated waste derived from fuel manufacturing, and construction debris from the remodeling of the 313 Building.

  5. Geochemical characteristics of sandstones from Cretaceous ...

    Indian Academy of Sciences (India)

    The Trichinopoly Group (later redesignated as Garudamangalam) has unconformable relationship with underlying Uttatur Group and is divided into lower Kulakanattam Formation and upper Anaipadi Formation. These calcareous sandstones are analysed major, trace and rare earth elements (REEs) to find out CIA, CIW, ...

  6. Cleanup Verification Package for the 118-F-1 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    E. J. Farris and H. M. Sulloway


    This cleanup verification package documents completion of remedial action for the 118-F-1 Burial Ground on the Hanford Site. This burial ground is a combination of two locations formerly called Minor Construction Burial Ground No. 2 and Solid Waste Burial Ground No. 2. This waste site received radioactive equipment and other miscellaneous waste from 105-F Reactor operations, including dummy elements and irradiated process tubing; gun barrel tips, steel sleeves, and metal chips removed from the reactor; filter boxes containing reactor graphite chips; and miscellaneous construction solid waste.

  7. The Bouznika Cambrian barite deposit (Morocco), an early mineralization on the Iapetus margin (United States)

    Jébrak, Michel; el Wartiti, Mohamed; Marcoux, Eric; Zaharoui, Mohamed


    Most of Morocco's barite production comes from deposits of epigenetic origin emplaced during Mesozoic time and hosted by Cambrian formations. Located in the Hercynian Meseta, the Bouznika deposit is associated with the Cambrian Oued Rhebar bimodal volcanic complex. Barite occurs as both stockworks and stratiform lenses within felsic tuffs and epiclastites, and is associated with a potassic alteration characterized by the presence of sericite. Lead and sulphur isotope analyses demonstrate that emplacement occurred during Cambrian time when barite-enriched hydrothermal fluids, likely of volcanic origin, mixed with sulphur from seawater. The Cambrian formations hosting the Bouznika, Jbel Irhoud and Seksaoua barite deposits are located near the faulted limit of the Meseta's lower Palaeozoic Iapetus rift on the northwestern edge of the Gondwana continent, suggesting that they formed during the Mesozoic reworking of early Cambrian concentrations.

  8. petrography and depositional environments of the sandstones in ...

    African Journals Online (AJOL)

    presence of quartz overgrowths in some of the sandstones. This study has shown that the sandstones in the area are deposited by fluvial dominated processes, with the interaction of beach processes, though to a lesser degree. KEYWORDS: textural analysis, sandstone petrography, depositional setting. INTRODUCTION.

  9. Testing alternative tectonic models of Palaeotethys in the E Mediterranean region: new U-Pb and Lu-Hf isotopic analyses of detrital zircons from Late Carboniferous and Late Triassic sandstones associated with the Anatolide and Tauride blocks (S Turkey) (United States)

    Ustaömer, Timur; Ayda Ustaömer, Petek; Robertson, Alastair; Gerdes, Axel


    Alternative tectonic models of Palaeotethys during Late Palaeozoic-Early Mesozoic time infer: 1. southward subduction beneath the north margin of Gondwana; 2. northward subduction beneath the south margin of Eurasia, or 3. double subduction (northwards and southwards), at least during Late Carboniferous. U-Pb and Lu-Hf isotopic analysis of detrital zircons, extracted from sandstones, can provide strong indications of age and identity of source terranes. Here, we consider the provenance of both Late Carboniferous and Late Triassic sandstones from both relatively allochthonous and relatively autochthonous units that are all spatially associated with the Anatolide and Tauride continental blocks. The relatively allochthonous units are sandstones (3 samples) from the Late Carboniferous Aladaǧ Nappe (Tauride; in the east), the Konya Complex (Anatolide; central area) and the Karaburun Mélange (Tauride-related; in the west). The relatively autochthonous units are Late Triassic sandstones (4 samples) from the Üzümdere Formation, the Kasımlar Formation (both western Taurides) and the Güvercinlik Formation (Karaburun Peninsula-Tauride related; far west). The Late Carboniferous sandstones from the three relatively allochthonous units are dominated by Precambrian zircon populations, the age distribution of which suggests derivation from two contrasting source regions: First, a NE African-type source (i.e. Saharan craton) for the sandstones of the Konya Mélange and the Aladaǧ Nappe because these sediments have prominent zircon populations dated at 0.5-0.7, 0.8 and 0.9-1.1 Ga. Palaeozoic zircons are minimal in the sandstones of the Aladaǧ Nappe and the Konya Complex (3 and 5% of the whole data, respectively) and are confined to Cambrian to Ordovician. Secondly, a contrasting NW African-type source is inferred for sandstone from the Karaburun Mélange because of the marked absence of Tonian-Stenian zircons and the predominance of ~2 Ga zircons over ~2.5 Ga zircons. In

  10. Sequence stratigraphy of the Upper Cambrian (Furongian; Jiangshanian and Sunwaptan) Tunnel City Group, Upper Mississippi Valley: Transgressing assumptions of cratonic flooding (United States)

    Eoff, Jennifer D.


    New data from detailed measured sections permit comprehensive analysis of the sequence framework of the Furongian (Upper Cambrian; Jiangshanian and Sunwaptan stages) Tunnel City Group (Lone Rock Formation and Mazomanie Formation) of Wisconsin and Minnesota. The sequence-stratigraphic architecture of the lower part of the Sunwaptan Stage at the base of the Tunnel City Group, at the contact between the Wonewoc Formation and Lone Rock Formation, records the first part of complex polyphase flooding (Sauk III) of the Laurentian craton, at a scale smaller than most events recorded by global sea-level curves. Flat-pebble conglomerate and glauconite document transgressive ravinement and development of a condensed section when creation of accommodation exceeded its consumption by sedimentation. Thinly-bedded, fossiliferous sandstone represents the most distal setting during earliest highstand. Subsequent deposition of sandstone characterized by hummocky or trough cross-stratification records progradational pulses of shallower, storm- and wave-dominated environments across the craton before final flooding of Sauk III commenced with carbonate deposition during the middle part of the Sunwaptan Stage. Comparison of early Sunwaptan flooding of the inner Laurentian craton to published interpretations from other parts of North America suggests that Sauk III was not a single, long-term accommodation event as previously proposed.

  11. Radioactive Waste Burial Grounds. Environmental Information Document

    Energy Technology Data Exchange (ETDEWEB)

    Jaegge, W.J.; Kolb, N.L.; Looney, B.B.; Marine, I.W.; Towler, O.A.; Cook, J.R.


    This document provides environmental information on postulated closure options for the Radioactive Waste Burial Grounds at the Savannah River Plant and was developed as background technical documentation for the Department of Energy`s proposed Environmental Impact Statement (EIS) on waste management activities for groundwater protection at the plant. The results of groundwater and atmospheric pathway analyses, accident analysis, and other environmental assessments discussed in this document are based upon a conservative analysis of all foreseeable scenarios as defined by the National Environmental Policy Act (CFR, 1986). The scenarios do not necessarily represent actual environmental conditions. This document is not meant to be used as a closure plan or other regulatory document to comply with required federal or state environmental regulations. The closure options considered for the Radioactive Waste Burial Grounds are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical and/or radioactive constituents are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated.

  12. Origin of a classic cratonic sheet sandstone: Stratigraphy across the Sauk II-Sauk III boundary in the Upper Mississippi Valley (United States)

    Runkel, Anthony C.; McKay, R.M.; Palmer, A.R.


    The origin of cratonic sheet sandstones of Proterozoic and early Paleozoic age has been a long-standing problem for sedimentologists. Lower Paleozoic strata in the Upper Mississippi Valley are best known for several such sandstone bodies, the regional depositional histories of which are poorly understood. We have combined outcrop and subsurface data from six states to place the Upper Cambrian Wonewoc (Ironton and Galesville) Sandstone in a well-constrained stratigraphic framework across thousands of square kilometers. This framework makes it possible for the first time to construct a regional-scale depositional model that explains the origin of this and other cratonic sheet sandstones. The Wonewoc Sandstone, although mapped as a single contiguous sheet, is a stratigraphically complex unit that was deposited during three distinct conditions of relative sea level that span parts of four trilobite zones. During a relative highstand of sea level in Crepicephalus Zone time, quartzose sandstone lithofacies aggraded more or less vertically in nearshore-marine and terrestrial environments across much of the present-day out-crop belt around the Wisconsin arch. At the same time, finer grained, feldspathic sandstone, siltstone, and shale aggraded in deeper water immediately seaward of the quartzose sand, and shale and carbonate sediment accumulated in the most distal areas. During Aphelaspis and Dunderbergia Zones time a relative fall in sea level led to the dispersal of quartzose sand into a basinward-tapering, sheet-like body across much of the Upper Mississippi Valley. During early Elvinia Zone time a major transgression led to deposition of a second sheet sandstone that is generally similar to the underlying regressive sheet. The results of this investigation also demonstrate how subtle sequence-bounding unconformities may be recognized in mature, cratonic siliciclastics. We place the Sauk II-Sauk III subsequence boundary at the base of the coarsest bed in the Wonewoc

  13. Customary right to befitting burial: a jurisprudential appraisal of four ...

    African Journals Online (AJOL)

    These symbols reveal unique rights for the people's entitlement. Among the rights to which an African is entitled is the right to befitting burial/funerals. This right comes with it, certain duties and/or obligations. The aim of this paper is to deconstruct the elements of applicable burial customs with a view to demonstrating their ...

  14. Urban Stream Burial Increases Watershed-Scale Nitrate Export.

    Directory of Open Access Journals (Sweden)

    Jake J Beaulieu

    Full Text Available Nitrogen (N uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in buried than in open streams before being removed from the water column, indicating that burial substantially reduces N uptake in streams. Simulation modeling suggests that as burial expands throughout a river network, N uptake rates increase in the remaining open reaches which somewhat offsets reduced N uptake in buried reaches. This is particularly true at low levels of stream burial. At higher levels of stream burial, however, open reaches become rare and cumulative N uptake across all open reaches in the watershed rapidly declines. As a result, watershed-scale N export increases slowly at low levels of stream burial, after which increases in export become more pronounced. Stream burial in the lower, more urbanized portions of the watershed had a greater effect on N export than an equivalent amount of stream burial in the upper watershed. We suggest that stream daylighting (i.e., uncovering buried streams can increase watershed-scale N retention.

  15. Redefining kin and family social relations: burial societies and ...

    African Journals Online (AJOL)

    This paper discusses the provision of financial relief to members' households by women-centred local institutions known as burial societies (diswaeti) in the event of death. In burial societies, mortality occupies the centre stage, not as a final defeat of human effort but as an inspiration for individual and collective ...

  16. Dialectics of Burial and Teritoriality in Barclays Ayakoroma's A ...

    African Journals Online (AJOL)

    AFRREV LALIGENS: An International Journal of Language, Literature and Gender Studies ... Thus appropriating the literary investigative approach, which is essentially predicated on critical content analysis, the paper examines the dialectic of death, burial ... Keywords: Death, burial nationalism, territoriality, representation ...

  17. New geochronologic and stratigraphic evidence confirms the paleocene age of the dinosaur-bearing ojo alamo sandstone and animas formation in the San Juan Basin, New Mexico and Colorado (United States)

    Fassett, J.E.


    Dinosaur fossils are present in the Paleocene Ojo Alamo Sandstone and Animas Formation in the San Juan Basin, New Mexico, and Colorado. Evidence for the Paleo-cene age of the Ojo Alamo Sandstone includes palynologic and paleomagnetic data. Palynologic data indicate that the entire Ojo Alamo Sandstone, including the lower dinosaur-bearing part, is Paleocene in age. All of the palynomorph-productive rock samples collected from the Ojo Alamo Sandstone at multiple localities lacked Creta-ceous index palynomorphs (except for rare, reworked specimens) and produced Paleocene index palynomorphs. Paleocene palynomorphs have been identified strati-graphically below dinosaur fossils at two separate localities in the Ojo Alamo Sand-stone in the central and southern parts of the basin. The Animas Formation in the Colorado part of the basin also contains dinosaur fossils, and its Paleocene age has been established based on fossil leaves and palynology. Magnetostratigraphy provides independent evidence for the Paleocene age of the Ojo Alamo Sandstone and its dinosaur-bearing beds. Normal-polarity magnetochron C29n (early Paleocene) has been identified in the Ojo Alamo Sandstone at six localities in the southern part of the San Juan Basin. An assemblage of 34 skeletal elements from a single hadrosaur, found in the Ojo Alamo Sandstone in the southern San Juan Basin, provided conclusive evidence that this assemblage could not have been reworked from underlying Cretaceous strata. In addition, geochemical studies of 15 vertebrate bones from the Paleocene Ojo Alamo Sandstone and 15 bone samples from the underlying Kirtland Formation of Late Creta-ceous (Campanian) age show that each sample suite contained distinctly different abundances of uranium and rare-earth elements, indicating that the bones were miner-alized in place soon after burial, and that none of the Paleocene dinosaur bones ana-lyzed had been reworked. ?? U.S. Geological Survey, Public Domain April 2009.

  18. Performance of Different Acids on Sandstone Formations

    Directory of Open Access Journals (Sweden)

    M. A. Zaman


    Full Text Available Stimulation of sandstone formations is a challenging task, which involves several chemicals and physical interactions of the acid with the formation. Some of these reactions may result in formation damage. Mud acid has been successfully used to stimulate sandstone reservoirs for a number of years. It is a mixture of hydrofluoric (HF and hydrochloric (HCl acids designed to dissolve clays and siliceous fines accumulated in the near-wellbore region. Matrix acidizing may also be used to increase formation permeability in undamaged wells. The change may be up to 50% to 100% with the mud acid. For any acidizing process, the selection of acid (Formulation and Concentration and the design (Pre-flush, Main Acid, After-flush is very important. Different researchers are using different combinations of acids with different concentrations to get the best results for acidization. Mainly the common practice is combination of Hydrochloric Acid – Hydrofluoric with Concentration (3% HF – 12% HCl. This paper presents the results of a laboratory investigation of Orthophosphoric acid instead of hydrochloric acid in one combination and the second combination is Fluoboric and formic acid and the third one is formic and hydrofluoric acid. The results are compared with the mud acid and the results calculated are porosity, permeability, and FESEM Analysis and Strength tests. All of these new combinations shows that these have the potential to be used as acidizing acids on sandstone formations.

  19. The onset of the 'Ordovician Plankton Revolution' in the late Cambrian

    DEFF Research Database (Denmark)

    Servais, Thomas; Perrier, Vincent; Danelian, Taniel


    The 'Great Ordovician Biodiversification Event' comprises the rapid diversification of marine organisms during the Ordovician Period. It is now clear that this adaptive radiation started for some organisms already in the Cambrian and continued for others beyond the end of the Ordovician, making...... groups (e.g., arthropods, molluscs) that were part of the Cambrian benthos and that later occupied pelagic niches. In addition, we focus also on data indicating evidence for a late Cambrian to Ordovician origin of planktotrophy in invertebrate larvae. It can be concluded that none of the diversifications...

  20. Plated Cambrian Bilaterians Reveal the Earliest Stages of Echinoderm Evolution (United States)

    Zamora, Samuel; Rahman, Imran A.; Smith, Andrew B.


    Echinoderms are unique in being pentaradiate, having diverged from the ancestral bilaterian body plan more radically than any other animal phylum. This transformation arises during ontogeny, as echinoderm larvae are initially bilateral, then pass through an asymmetric phase, before giving rise to the pentaradiate adult. Many fossil echinoderms are radial and a few are asymmetric, but until now none have been described that show the original bilaterian stage in echinoderm evolution. Here we report new fossils from the early middle Cambrian of southern Europe that are the first echinoderms with a fully bilaterian body plan as adults. Morphologically they are intermediate between two of the most basal classes, the Ctenocystoidea and Cincta. This provides a root for all echinoderms and confirms that the earliest members were deposit feeders not suspension feeders. PMID:22701623

  1. Identification and Tracing Groundwater Contamination by Livestock Burial Sites (United States)

    Ko, K.; Ha, K.; Park, S.; Kim, Y.; Lee, K.


    Foot-and-mouth disease (FMD) or hoof-and-mouth disease is a severe plague for animal farming that affects cloven-hoofed animals such as cattle, pigs, sheep, and goats. Since it is highly infectious and can be easily proliferated by infected animals, contaminated equipments, vehicles, clothing, people, and predators. It is widely known that the virus responsible for FMD is a picornavirus, the prototypic member of the genus Aphthovirus. A serious outbreak of foot-and-mouth disease, leading to the stamping out of 3.53 millions of pigs and cattle and the construction of 4,538 burial sites until 15th March, 2011. The build-up of carcass burial should inevitably produce leachate by the decomposition of buried livestock affecting the surround environment such as air, soil, groundwater, and surface water. The most important issues which are currently raised by scientists are groundwater contamination by leachate from the livestock burial sites. This study examined the current status of FMD outbreak occurred in 2010-2011 and the issues of groundwater contamination by leachate from livestock burial sites. The hydrogeochemical, geophysical, and hydrogeological studies were executed to identify and trace groundwater contamination by leachate from livestock burial sites. Generally livestock mortality leachate contains high concentrations of NH3-N, HCO3-, Cl-, SO42-, K+, Na+, P along with relative lesser amounts of iron, calcium, and magnesium. The groundwater chemical data around four burial sites showed high NH3-N, HCO3-, and K+ suggesting the leachate leakage from burial sites. This is also proved by resistivity monitoring survey and tracer tests. The simulation results of leachate dispersion showed the persistent detrimental impacts for groundwater environment for a long time (~50 years). It is need to remove the leachate of burial sites to prevent the dispersion of leachate from livestock burial to groundwater and to monitor the groundwater quality. The most important

  2. The sedimentological characteristics of microbialites of the Cambrian in the vicinity of Beijing, China

    Directory of Open Access Journals (Sweden)

    Yin-Ye Wu


    Full Text Available With oil and gas exploration transferring to deeper and more ancient marine strata, more researches have been conducted about the Meso–Neoproterozoic and Cambrian microbial carbonate rocks by petroleum geologists. The Cambrian deposits experienced the first transgression of the Paleozoic, with shallow marine facies depositing in most areas, which are favorable for different kinds of biological reproduction. The Lower Cambrian in Beijing area is lithologically dominated by purple red shales interbedded with limestones, the Middle Cambrian is mainly composed of thick oolitic limestones, and the Upper Cambrian consists of thin limestones and flat-pebble conglomerates. Two beds of microbial carbonate rocks were discovered in the Cambrian outcrops in the vicinity of Beijing. One is from the Zhangxia Formation of Middle Cambrian, and the other is from the Gushan Formation of Upper Cambrian. The microbialites are characterized by combination of multiple stromatolites forming different bioherms. The bioherms are mostly in oval shape and with different sizes, which are 3–4 m long, and 1–3 m high. The surrounding strata beneath the bioherms are oolitic limestones. A central core of flat-pebble conglomerates occurred within each bioherm. Wavy or columnar stromatolites grow on the basis of flat-pebble conglomerates, with dentate erosional surfaces. The bioherm carbonate rocks are interpreted as products from a deep ramp sedimentary environment where potential oil and gas reservoirs can be found. The analysis of sedimentological characteristics of bioherm carbonate rocks and its lithofacies palaeogeography has significant implication for petroleum exploration. Research on geological record of microbialites is beneficial to investigating the Earth evolution, biodiversity, palaeoenvironment and palaeoclimate change, as well as biological extinction event during geological transitions. It also gives warning to human beings of modern biological crisis.

  3. Early Cambrian origin of modern food webs: evidence from predator arrow worms. (United States)

    Vannier, J; Steiner, M; Renvoisé, E; Hu, S-X; Casanova, J-P


    Although palaeontological evidence from exceptional biota demonstrates the existence of diverse marine communities in the Early Cambrian (approx. 540-520 Myr ago), little is known concerning the functioning of the marine ecosystem, especially its trophic structure and the full range of ecological niches colonized by the fauna. The presence of a diverse zooplankton in Early Cambrian oceans is still an open issue. Here we provide compelling evidence that chaetognaths, an important element of modern zooplankton, were present in the Early Cambrian Chengjiang biota with morphologies almost identical to Recent forms. New information obtained from the lowermost Cambrian of China added to previous studies provide convincing evidence that protoconodont-bearing animals also belonged to chaetognaths. Chaetognaths were probably widespread and diverse in the earliest Cambrian. The obvious raptorial function of their circumoral apparatuses (grasping spines) places them among the earliest active predator metazoans. Morphology, body ratios and distribution suggest that the ancestral chaetognaths were planktonic with possible ecological preferences for hyperbenthic niches close to the sea bottom. Our results point to the early introduction of prey-predator relationships into the pelagic realm, and to the increase of trophic complexity (three-level structure) during the Precambrian-Cambrian transition, thus laying the foundations of present-day marine food chains.

  4. Lower Cambrian polychaete from China sheds light on early annelid evolution (United States)

    Liu, Jianni; Ou, Qiang; Han, Jian; Li, Jinshu; Wu, Yichen; Jiao, Guoxiang; He, Tongjiang


    We herein report a fossilized polychaete annelid, Guanshanchaeta felicia gen. et sp. nov., from the Lower Cambrian Guanshan Biota (Cambrian Series 2, stage 4). The new taxon has a generalized polychaete morphology, with biramous parapodia (most of which preserve the evidence of chaetae), an inferred prostomium bearing a pair of appendages, and a bifid pygidium. G. felicia is the first unequivocal annelid reported from the Lower Cambrian of China. It represents one of the oldest annelids among those from other early Paleozoic Lagerstätten including Sirius Passet from Greenland (Vinther et al., Nature 451: 185-188, 2008) and Emu Bay from Kangaroo island (Parry et al., Palaeontology 57: 1091-1103, 2014), and adds to our increasing roll of present-day animal phyla recognized in the early Cambrian Guanshan Biota. This finding expands the panorama of the Cambrian `explosion' exemplified by the Guanshan Biota, suggesting the presence of many more fossil annelids in the Chengjiang Lagerstätte and the Kaili Biota. In addition, this new taxon increases our knowledge of early polychaete morphology, which suggests that polychaete annelids considerably diversified in the Cambrian.

  5. The Ediacaran-Cambrian transition in the Cantabrian Zone 1 (North Spain): sub-Cambrian weathering, K-metasomatism and provenance of detrital series


    Ugidos, J.M.; Barba, P.; Valladares, M.I.; Suarez, M.; Ellam, R.M.


    The Upper Ediacaran detrital succession in the Cantabrian Zone shows geochemical and mineralogical changes resulting from sub-Cambrian weathering during the Late Ediacaran worldwide sea-level fall. Relative to the unaltered rocks the altered ones show crosscutting rubefaction of varying thickness and remarkable increase in illite, K2O, Rb and Cs indicating K-metasomatism, and also depletion in MgO, CaO, Na2O, Be and Sr, but not in Zr, Nb, Y or Sc. The basal Cambrian siliciclastic rocks mostly...

  6. Effect of temperature on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus

    with the Kozeny equation and the Klinkenberg procedure. Both methods overestimated the measured brine permeability; this suggests that additional factors, possibly related to clay morphology, contributed to a lower brine permeability. Thermal expansion would have a negligible effect on permeability as estimated...... interaction forces. Quantitative analysis of images, in which mineralogy was mapped based on backscatter electron intensity in combination with energy dispersive X-ray analysis by using the QEMSCAN® system, was used to compare a tested sample to an untested Berea sandstone sample. During the experiment...

  7. Effects of urban stream burial on nitrogen uptake and ... (United States)

    Urbanization has resulted in extensive burial and channelization of headwater streams, yet little is known about impacts on stream ecosystem functions critical for reducing downstream nitrogen pollution. To characterize the biogeochemical impact of stream burial, we measured NO3- uptake, using 15N-NO3- isotope tracer releases, and whole stream metabolism, during four seasons in three paired buried and open streams reaches within the Baltimore Ecosystem Study Long-term Ecological Research Network. Stream burial increased NO3- uptake lengths, by a factor of 7.5 (p metabolism were primarily explained by decreased transient storage and light availability in buried streams. We estimate that stream burial increases daily watershed nitrate export by as much as 500% due to decreased in-stream retention and may considerably decrease carbon export via decreased primary production. These results

  8. Scour and Burial Mechanics of Objects in the Nearshore (United States)


    in local sand level may increase burial depth or expose the object. Scour and burial predictions of mines and mine-like objects were tested in... Rockport , TX), collision coast (Torrey Pines and Scripps Beach, CA), and trailing-edge coast (Duck, NC). Mines residing within the envelope of...2003. During that time, four traveling cold fronts crossed over the test site producing short period storm waves of up to 3-m local rms waveheight [60

  9. Diagenesis, provenance and reservoir quality of Triassic TAGI sandstones from Ourhoud field, Berkine (Ghadames) Basin, Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, C.; Arribas, J.; Tortosa, A. [Universidad Complutense de Madrid, (Spain). Departamento de Petrologia y Geoquimica; Kalin, O. [Universidad Complutense, Madrid (Spain). Departamento de Paleontologia


    The Triassic TAGI (Trias Argilo-Greseux Inferieur) fluvial sandstones are the main oil reservoirs in the Berkine Basin, Algeria. Nonetheless, their provenance and diagenesis, and their impact on reservoir quality, are virtually unknown. Samples from the Ourhoud field, representing the Lower, Middle and Upper TAGI subunits, were studied using a combination of petrographic, mineralogical and geochemical techniques. The Lower TAGI sandstones have an average framework composition of Q{sub 98.3}F{sub 0.6}R{sub 1.1} and 95% of the quartz grains are monocrystalline. By contrast, the Middle-Upper TAGI sandstones have an average framework composition of Q{sub 88.3}F{sub 9.8}R{sub 1.9} and 79% of the quartz grains are monocrystalline. The Lower TAGI quartz arenites derived from Paleozoic siliclastic rocks, whereas the Middle-Upper TAGI subarkoses originated mainly from metamorphic terrains. This change in provenance is a potential criterion for correlation within the TAGI. Also, this change has contributed to the significantly different diagenetic paths followed by the Lower TAGI quartz arenites and the Middle-Upper TAGI subarkoses. Grain-coating illitic clays are abundant in the Lower TAGI, where they exert a critical control on reservoir quality. These clays are interpreted as pedogenic and/or infiltrated in origin and to have had, in part, smectitic precursors. Shallow burial Fe-dolomite cementation was favored in the downthrown block of the field-bounding fault, where it contributed to the poor reservoir quality. Magnesite-siderite cements are multiphase. The earliest generation is composed of Fe-rich magnesite that precipitated during shallow burial from hypersaline fluids with high Mg/Ca ratios, probably refluxed residual brines associated with the Liassic evaporites. Later magnesite-siderite generations precipitated during deeper burial from waters with progressively higher Fe/Mg ratios. Authigenic vermicular kaolin largely consists of dickite that replaced previously

  10. Splash-like marine biodiversity additions after the cambrian

    Directory of Open Access Journals (Sweden)

    Ruban Dmitry A.


    Full Text Available Some Phanerozoic biotic radiations in the marine realm led to marine biodiversity additions, i.e., increases in the global number of genera to unprecedented levels. Each of the two alternative biodiversity curves implies five post-Cambrian events of this kind, which coincided with parts of the biotic radiations. However, differences between these curves do not allow to find coherent marine biodiversity additions with the only exception of those occurred at the interval of the Great Ordovician Biodiversification. The attempted interpretations indicate that the marine biodiversity additions increased the number of marine genera by 10-30 % (from the previous unprecedented level to that new. All additions were relatively brief and occurred as splashes throughout the Phanerozoic. Peculiar intrinsic and extrinsic factors, as well as the speed of diversification should be considered when triggers of these events are looked for. Undoubtedly, splash-like marine biodiversity additions played an important role in the evolution of life in the sea, but a lot of research is required in order to understand their true nature.

  11. Scour and Burial of Bottom Mines: a Primer for Fleet Use


    Inman, Douglas L.; Jenkins, Scott A.


    This primer is for fleet use as a means of rapid access to information on scour, burial, and re-exposure of bottom mines placed in nearshore waters. The format is easily adapted to a computer slide show where sequential illustrations such as progressive mine scour and burial could be in animated form. The illustrations detail mechanisms and burial rates characteristic of coastal and sediment type. The primer also addresses the ranges of uncertainty in mine burial estimates by showing burial d...

  12. Middle Cambrian siliceous sponge-calcimicrobe buildups (Daegi Formation, Korea): Metazoan buildup constituents in the aftermath of the Early Cambrian extinction event (United States)

    Hong, Jongsun; Cho, Seong-Hyeon; Choh, Suk-Joo; Woo, Jusun; Lee, Dong-Jin


    Numerous decimetre- to metre-scale carbonate buildups dominated by siliceous sponges and the calcimicrobe Epiphyton are reported from the Middle Cambrian (Series 3) Daegi Formation of Korea. These siliceous sponge-Epiphyton buildups consist predominantly of grey micritic boundstones with dark clots and/or white clumps. The boundstones contain sponge spicule networks interpreted as the calcified remains of siliceous sponges. The white clumps and dark clots in the boundstones represent variously preserved Epiphyton. Siliceous sponges form constructional pore space and are commonly encrusted by Epiphyton. The sponges were probably the primary frame-builders, providing substrates for the attachment and subsequent growth of Epiphyton. Epiphyton is considered to be a binder when covering the surface of siliceous sponges, and a subordinate frame-builder when filling depositional voids created by siliceous sponges or growing on top of other Epiphyton growth bundles. The siliceous sponge-Epiphyton buildups of the Daegi Formation show similarities to previously described Late Cambrian (Furongian) anthaspidellid-calcimicrobe buildups from Iran and the USA. Together with recently reported examples from the Zhangxia Formation of eastern China, the sponge-Epiphyton buildups from Korea represent some of the oldest metazoan-calcimicrobe buildups, after the extinction of most archaeocyaths at the end of the Early Cambrian (Series 2). This implies that the incorporation of metazoans in Middle Cambrian (Series 3) carbonate buildups occurred much earlier than previously known. The buildup-forming siliceous sponges described in this study demonstrate that their role in Early Phanerozoic carbonate buildups has been grossly underestimated.

  13. Nodular features from Proterozoic Sonia Sandstone, Jodhpur Group ...

    Indian Academy of Sciences (India)

    From granulometric and microscopic (optical and scanning electron) studies carried out on sandstones from the nodules and their host sandstones, geochemical analysis (SEM-EDAX) of intragranular cement present within Type I nodules, and appreciation of control of associated fracture system within Type II nodules, it is ...

  14. Petrography and depositional environments of the sandstones in ...

    African Journals Online (AJOL)

    Indurated sandstone samples were cut into thin sections for petrographic analysis while a total of 100 pebbles from OAM/1/Abuul were subjected to morphometric analysis. The thin section studies involved the determination of the texture and mineral/framework element compositions of the sandstones through point counting ...

  15. Modal analysis and geochemistry of two sandstones of the Bhander ...

    Indian Academy of Sciences (India)

    fragments are classified as quartz arenite to sublitharenite. The sandstone geochemically reflects high SiO2, moderate Al2O3 and low CaO and Na2O type arenite. The high concentration of HFSE such as Zr, Hf, and Th/Sc, Th/U ratios in these sandstones indicate a mixed provenance. The chondrite normalized REE pattern ...

  16. Petrography and geochemistry of Jurassic sandstones from the ...

    Indian Academy of Sciences (India)

    Sandstones of Jhuran Formation from Jara dome, western Kachchh, Gujarat, India were studied for major, trace and rare earth element (REE) geochemistry to deduce their paleo-weathering, tectonic setting, source rock characteristics and provenance. Petrographic analysis shows that sandstones are having quartz grains ...

  17. Petrography and geochemistry of Jurassic sandstones from the ...

    Indian Academy of Sciences (India)

    V Periasamy

    Sandstones of Jhuran Formation from Jara dome, western Kachchh, Gujarat, India were studied for major, trace and rare earth element (REE) geochemistry to deduce their paleo-weathering, tectonic set- ting, source rock characteristics and provenance. Petrographic analysis shows that sandstones are having quartz grains ...

  18. Tectonic burial, thrust emplacement, and extensional exhumation of the Cabot nappe in the Appalachian hinterland of Cape Breton Island, Canada (United States)

    Lynch, Gregory


    Silurian imbricate thrusting, Early Devonian high-grade metamorphic nappe emplacement, and Devonian-Carboniferous extensional denudation characterize deformation in the Appalachian hinterland of Cape Breton Island. Compressional deformation following Early Silurian arc volcanism features imbrication of Cambrian-Precambrian basement rocks of Gondwana derivation with Ordovician-Silurian cover sequences across thick zones of mylonite during south directed transport. High grade metamorphism and gneissic rocks of late Silurian age in the region indicate that significant tectonic burial and crustal thickening occurred as a result of the thrusting. Partial denudation of the high grade assemblages occurred during Early Devonian thrust emplacement of the Cabot nappe toward the northwest, along the Highlands Shear Zone. The nappe is characterized by an amphibolitic gneiss and high-grade schist complex defining a large folded klippe above Silurian units. Kyanite is widespread within the nappe, and a distinctive feature of the thrust sheet is the dynamothermal metamorphism of cooler greenschist-grade footwall rocks producing inverted isograds; staurolite is regionally distributed and occurs in pelitic units in the immediate footwall of the Highlands Shear Zone forming a discontinuous halo around the klippe. Greenschist-grade footwall rocks are exposed in structural windows as a result of folding and faulting. Shear sense indicators along the margins of the Cabot nappe have been rotated into their present positions due to superposed folding, providing apparent movement directions for the nappe. Complete exhumation to surface occurred during Late Devonian extension along the low-angle Margaree Shear Zone.

  19. Origin and diagenesis of clay minerals in relation to sandstone paragenesis: An example in eolian dune reservoirs and associated rocks, Permian upper part of the Minnelusa Formation, Powder River basin, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Pollastro, R.M.; Schenk, C.J. (Geological Survey, Denver, CO (United States))


    Eolian dune sandstones are the principal reservoir rocks in the Permian upper part of the Minnelusa Formation, Powder River basin, Wyoming. These sandstones formed as shorelines retreated and dunes migrated across siliciclastic sabkhas. Sandstones are mainly quartzarenites; on average, clay minerals constitute about 5 wt.% the whole rock. Although present in minor amounts, clay minerals play an important role in the diagenetic evolution of these sandstones. Allogenic clay minerals are present in shaly rock fragments and laminae. Early infiltration of clays into porous sabkha sands commonly form characteristic menisei or bridges between framework grains or, when more extensive, form coatings or rims on grain surfaces. Authigenic clays include nearly pure smectite, mixed-layer illite/smectite (I/S), and late diagenetic illite and corrensite; these clay minerals are present as pore-lining cements. In addition to the deposition and neoformation of clay minerals throughout sandstone paragenesis, the conversion of smectite to illite occurred as temperatures increased with progressive burial. A temperature of 103C is calculated at a present depth of 3,200 m using a geothermal gradient of 30C/km and a mean annual surface temperature of 7C. After correction for uplift and erosion (250 m), the maximum calculated temperature for the conversion of all random I/S to ordered I/S is 100C. This calculated temperature is in excellent agreement with temperatures of 100-110C implied from I/S geothermometry.

  20. MicroRNAs and metazoan macroevolution: insights into canalization, complexity, and the Cambrian explosion. (United States)

    Peterson, Kevin J; Dietrich, Michael R; McPeek, Mark A


    One of the most interesting challenges facing paleobiologists is explaining the Cambrian explosion, the dramatic appearance of most metazoan animal phyla in the Early Cambrian, and the subsequent stability of these body plans over the ensuing 530 million years. We propose that because phenotypic variation decreases through geologic time, because microRNAs (miRNAs) increase genic precision, by turning an imprecise number of mRNA transcripts into a more precise number of protein molecules, and because miRNAs are continuously being added to metazoan genomes through geologic time, miRNAs might be instrumental in the canalization of development. Further, miRNAs ultimately allow for natural selection to elaborate morphological complexity, because by reducing gene expression variability, miRNAs increase heritability, allowing selection to change characters more effectively. Hence, miRNAs might play an important role in shaping metazoan macroevolution, and might be part of the solution to the Cambrian conundrum.

  1. Sulfate burial constraints on the Phanerozoic sulfur cycle. (United States)

    Halevy, Itay; Peters, Shanan E; Fischer, Woodward W


    The sulfur cycle influences the respiration of sedimentary organic matter, the oxidation state of the atmosphere and oceans, and the composition of seawater. However, the factors governing the major sulfur fluxes between seawater and sedimentary reservoirs remain incompletely understood. Using macrostratigraphic data, we quantified sulfate evaporite burial fluxes through Phanerozoic time. Approximately half of the modern riverine sulfate flux comes from weathering of recently deposited evaporites. Rates of sulfate burial are unsteady and linked to changes in the area of marine environments suitable for evaporite formation and preservation. By contrast, rates of pyrite burial and weathering are higher, less variable, and largely balanced, highlighting a greater role of the sulfur cycle in regulating atmospheric oxygen.

  2. The Semiotics of Pemature Burial: Feminism in a Postfeminist Age

    Directory of Open Access Journals (Sweden)

    Mary Hawkesworth


    Full Text Available In this article, I will explore how the death of feminism is represented in order to plumb the larger meanings embedded in proclamations of feminism’s symbolic death. I will begin by investigating two mechanisms by which feminism’s death has been produced to unearth the tacit values of feminism’s morticians. I will then consider competing accounts of the “signs of death” in order to explore how particular assumptions about the ontology of feminism are tied to specific forms of metaphorical death. Given the particular kind of distortion involved in the premature burial of a thriving global feminism, the final section of the article situates contemporary feminism’s death knell in the context of a gendered history of live burial practices. By excavating and interpreting such archaic practices, I will link the rhetorical burial of contemporary feminism to an ongoing effort to undermine feminist struggles for social justice.

  3. The Lower and Middle Cambrian Leithsville Formation within the Wallkill River Valley, Sussex County, New Jersey: Its stratigraphy and archaeological relevance

    Energy Technology Data Exchange (ETDEWEB)

    Brewer, M.C. (Hunter College, New York, NY (United States). Dept. of Geology and Geography)


    The Leithsville Formation occurs as series of northeast-southwest trending outcrops within the Hamburg and Unionville Quadrangles of northwestern New Jersey. The lower Califon Member, approximately 30 feet thick, is best developed in structural sags and topographic lows on the Precambrian surface and where the Hardyston Formation (Lower Cambrian) is thin or absent. It occurs as dark gray, coarsely crystalline, stylolitic dolomite. Vugs bearing quartz, orange calcite, and clots of sphalerite are common. Archaeocyathus is present near the base of the section, which is greater than 30 feet thick in the Vernon Valley. Approximately 120 feet of the Hamburg Member occurs in the study area. The lower unit is a series of finely laminated, thinly bedded alternating phyllitic shales and dolomites that grade upward to thicker cycles of dense, dark gray dolomite with intermittent olive green sandstone units. At several locales, this unit is followed by a series of greenish-gray to reddish-brown alternating shales and dolomites, which bear mud cracks and ripple marks. A distinct rubble zone and unconformity-bounded chert sequence occurs near the top of this member. Measured sections of the poorly exposed upper Wallkill Member have revealed 70 feet of coarse grained, medium gray, stylolitic dolomite with abundant algal stromatolites. Several chert-bounded unconformities occur midway in the section, which is internally brecciated and sulfide-rich. Chert occurring as pods within this member has been the focus of prehistoric mining activity within the axis of the valley.

  4. Sedimentary facies of the upper Cambrian (Furongian; Jiangshanian and Sunwaptan) Tunnel City Group, Upper Mississippi Valley: new insight on the old stormy debate (United States)

    Eoff, Jennifer D.


    New data from detailed measured sections permit a comprehensive revision of the sedimentary facies of the Furongian (upper Cambrian; Jiangshanian and Sunwaptan stages) Tunnel City Group (Lone Rock Formation and Mazomanie Formation) of Wisconsin and Minnesota. Heterogeneous sandstones, comprising seven lithofacies along a depositional transect from shoreface to transitional-offshore environments, record sedimentation in a storm-dominated, shallow-marine epicontinental sea. The origin of glauconite in the Birkmose Member and Reno Member of the Lone Rock Formation was unclear, but its formation and preserved distribution are linked to inferred depositional energy rather than just net sedimentation rate. Flat-pebble conglomerate, abundant in lower Paleozoic strata, was associated with the formation of a condensed section during cratonic flooding. Hummocky cross-stratification was a valuable tool used to infer depositional settings and relative paleobathymetry, and the model describing formation of this bedform is expanded to address flow types dominant during its genesis, in particular the importance of an early unidirectional component of combined flow. The depositional model developed here for the Lone Rock Formation and Mazomanie Formation is broadly applicable to other strata common to the early Paleozoic that document sedimentation along flooded cratonic interiors or shallow shelves.

  5. Permeability and permeability anisotropy in Crab Orchard sandstone: Experimental insights into spatio-temporal effects (United States)

    Gehne, Stephan; Benson, Philip M.


    Permeability in tight crustal rocks is primarily controlled by the connected porosity, shape and orientation of microcracks, the preferred orientation of cross-bedding, and sedimentary features such as layering. This leads to a significant permeability anisotropy. Less well studied, however, are the effects of time and stress recovery on the evolution of the permeability hysteresis which is becoming increasingly important in areas ranging from fluid migration in ore-forming processes to enhanced resource extraction. Here, we report new data simulating spatio-temporal permeability changes induced using effective pressure, simulating burial depth, on a tight sandstone (Crab Orchard). We find an initially (measured at 5 MPa) anisotropy of 2.5% in P-wave velocity and 180% in permeability anisotropy is significantly affected by the direction of the effective pressure change and cyclicity; anisotropy values decrease to 1% and 10% respectively after 3 cycles to 90 MPa and back. Furthermore, we measure a steadily increasing recovery time (10-20 min) for flow parallel to cross-bedding, and a far slower recovery time (20-50 min) for flow normal to cross-bedding. These data are interpreted via strain anisotropy and accommodation models, similar to the ;seasoning; process often used in dynamic reservoir extraction.

  6. Geochemistry of Sulfur and Sulfur Compounds of the Cambrian Kuonamka Complex (Eastern Siberian Platform)


    T.M. Parfenova


    New results of research of sulfur from rocks and organic matter (OM) for the Kuonamka complex of the Lower and Middle Cambrian in the eastern Siberian platform have been demonstrated. It has been shown that in the rocks enriched in organic matter the amount of organic carbon controls not only the total content of sulfur and sulfide sulfur, but also the content of sulphate sulfur. It has been revealed that the sulfur content in bitumen extracts of Cambrian black shales in the northeastern Sibe...

  7. Mine impact burial prediction from one to three dimensions


    Chu, Peter C.


    Applied Mechanics Reviews, American Society of Mechanical Engineers, 62, 010802 The article of record as published may be located at The Navy’s mine impact burial prediction model creates a time history of a cylindrical or a noncylindrical mine as it falls through air, water, and sediment. The output of the model is the predicted mine trajectory in air and water columns, burial depth/orientation in sediment, as well as height, area, and volum...

  8. Extraordinary fossils reveal the nature of Cambrian life: a commentary on Whittington (1975) ‘The enigmatic animal Opabinia regalis, Middle Cambrian, Burgess Shale, British Columbia’ (United States)

    Briggs, Derek E. G.


    Harry Whittington's 1975 monograph on Opabinia was the first to highlight how some of the Burgess Shale animals differ markedly from those that populate today's oceans. Categorized by Stephen J. Gould as a ‘weird wonder’ (Wonderful life, 1989) Opabinia, together with other unusual Burgess Shale fossils, stimulated ongoing debates about the early evolution of the major animal groups and the nature of the Cambrian explosion. The subsequent discovery of a number of other exceptionally preserved fossil faunas of Cambrian and early Ordovician age has significantly augmented the information available on this critical interval in the history of life. Although Opabinia initially defied assignment to any group of modern animals, it is now interpreted as lying below anomalocaridids on the stem leading to the living arthropods. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750235

  9. Extraordinary fossils reveal the nature of Cambrian life: a commentary on Whittington (1975) 'The enigmatic animal Opabinia regalis, Middle Cambrian, Burgess Shale, British Columbia'. (United States)

    Briggs, Derek E G


    Harry Whittington's 1975 monograph on Opabinia was the first to highlight how some of the Burgess Shale animals differ markedly from those that populate today's oceans. Categorized by Stephen J. Gould as a 'weird wonder' (Wonderful life, 1989) Opabinia, together with other unusual Burgess Shale fossils, stimulated ongoing debates about the early evolution of the major animal groups and the nature of the Cambrian explosion. The subsequent discovery of a number of other exceptionally preserved fossil faunas of Cambrian and early Ordovician age has significantly augmented the information available on this critical interval in the history of life. Although Opabinia initially defied assignment to any group of modern animals, it is now interpreted as lying below anomalocaridids on the stem leading to the living arthropods. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

  10. Pressure sensitivity of low permeability sandstones (United States)

    Kilmer, N.H.; Morrow, N.R.; Pitman, J.K.


    Detailed core analysis has been carried out on 32 tight sandstones with permeabilities ranging over four orders of magnitude (0.0002 to 4.8 mD at 5000 psi confining pressure). Relationships between gas permeability and net confining pressure were measured for cycles of loading and unloading. For some samples, permeabilities were measured both along and across bedding planes. Large variations in stress sensitivity of permeability were observed from one sample to another. The ratio of permeability at a nominal confining pressure of 500 psi to that at 5000 psi was used to define a stress sensitivity ratio. For a given sample, confining pressure vs permeability followed a linear log-log relationship, the slope of which provided an index of pressure sensitivity. This index, as obtained for first unloading data, was used in testing relationships between stress sensitivity and other measured rock properties. Pressure sensitivity tended to increase with increase in carbonate content and depth, and with decrease in porosity, permeability and sodium feldspar. However, scatter in these relationships increased as permeability decreased. Tests for correlations between pressure sensitivity and various linear combinations of variables are reported. Details of pore structure related to diagenetic changes appears to be of much greater significance to pressure sensitivity than mineral composition. ?? 1987.

  11. Natural Erosion of Sandstone as Shape Optimisation. (United States)

    Ostanin, Igor; Safonov, Alexander; Oseledets, Ivan


    Natural arches, pillars and other exotic sandstone formations have always been attracting attention for their unusual shapes and amazing mechanical balance that leave a strong impression of intelligent design rather than the result of a stochastic process. It has been recently demonstrated that these shapes could have been the result of the negative feedback between stress and erosion that originates in fundamental laws of friction between the rock's constituent particles. Here we present a deeper analysis of this idea and bridge it with the approaches utilized in shape and topology optimisation. It appears that the processes of natural erosion, driven by stochastic surface forces and Mohr-Coulomb law of dry friction, can be viewed within the framework of local optimisation for minimum elastic strain energy. Our hypothesis is confirmed by numerical simulations of the erosion using the topological-shape optimisation model. Our work contributes to a better understanding of stochastic erosion and feasible landscape formations that could be found on Earth and beyond.

  12. albitization in the sandstones of inkisi in republic of congo

    African Journals Online (AJOL)


    optical microscope, supplemented by some observations and elemental microanalyses by scanning electron microscope (SEM). The optical polarizing .... relatively unaltered crystals of potassium feldspar, ... Plate I: Principal facies of albitization in the Inkisi Formation sandstone, observed under the optical microscope.

  13. Diagenesis and mass transfer between Permo-Triassic sandstones ...

    African Journals Online (AJOL)

    -Triassic sandstones of the Ulster Basin, UK, at different stratigraphic levels. The paragenetic sequences of authigenic minerals both in the sandy and fine-grained sediments (mudstones and siltstones) indicate red bed diagenetic trend.

  14. Hydrocarbon-generation in Cambrian-Silurian high- to over- mature source rocks, middle and upper Yangtze region, China

    National Research Council Canada - National Science Library

    Shu Tao; Yanbin Wang; Dazhen Tang; Hao Xu


    ... generation evolution. Based on a detailed study of the tectonic burial history and an analysis of the current degree of thermal evolution of the source rocks, this paper studied the burial history, the thermal history...

  15. Deformation bands in porous sandstones their microstructure and petrophysical properties

    Energy Technology Data Exchange (ETDEWEB)

    Torabi, Anita


    Deformation bands are commonly thin tabular zones of crushed or reorganized grains that form in highly porous rocks and sediments. Unlike a fault, typically the slip is negligible in deformation bands. In this dissertation the microstructure and petrophysical properties of deformation bands have been investigated through microscopy and numerical analysis of experimental and natural examples. The experimental work consists of a series of ring-shear experiments performed on porous sand at 5 and 20 MPa normal stresses and followed by microscopic examination of thin sections from the sheared samples. The results of the ring-shear experiments and comparison of them to natural deformation bands reveals that burial depth (level of normal stress in the experiments) and the amount of shear displacement during deformation are the two significant factors influencing the mode in which grains break and the type of shear zone that forms. Two end-member types of experimental shear zones were identified: (a) Shear zones with diffuse boundaries, which formed at low levels of normal stress and/or shear displacement; and (b) Shear zones with sharp boundaries, which formed at higher levels of normal stress and/or shear displacement. Our interpretation is that with increasing burial depth (approximately more than one kilometer, simulated in the experiments by higher levels of normal stress), the predominant mode of grain fracturing changes from flaking to splitting; which facilitates the formation of sharp-boundary shear zones. This change to grain splitting increases the power law dimension of the grain size distribution (D is about 1.5 in sharp boundary shear zones). Based on our observations, initial grain size has no influence in the deformation behavior of the sand at 5 MPa normal stresses. A new type of cataclastic deformation band is described through outcrop and microscopic studies; here termed a 'slipped deformation band'. Whereas previously reported cataclastic

  16. Large increases in carbon burial in northern lakes during the Anthropocene. (United States)

    Heathcote, Adam J; Anderson, N John; Prairie, Yves T; Engstrom, Daniel R; del Giorgio, Paul A


    Northern forests are important ecosystems for carbon (C) cycling and lakes within them process and bury large amounts of organic-C. Current burial estimates are poorly constrained and may discount other shifts in organic-C burial driven by global change. Here we analyse a suite of northern lakes to determine trends in organic-C burial throughout the Anthropocene. We found burial rates increased significantly over the last century and are up to five times greater than previous estimates. Despite a correlation with temperature, warming alone did not explain the increase in burial, suggesting the importance of other drivers including atmospherically deposited reactive nitrogen. Upscaling mean lake burial rates for each time period to global northern forests yields up to 4.5 Pg C accumulated in the last 100 years--20% of the total burial over the Holocene. Our results indicate that lakes will become increasingly important for C burial under future global change scenarios.

  17. Diagenesis Along Fractures in an Eolian Sandstone, Gale Crater, Mars (United States)

    Ming, D. W.; Yen, A. S.; Rampe, E. B.; Grotzinger, J. P.; Blake, D. F.; Bristow, T. F.; Chipera, S. J.; Downs, R.; Morris, R. V.; Morrison, S. M.; hide


    The Mars Science Laboratory rover Curiosity has been exploring sedimentary deposits in Gale crater since August 2012. The rover has traversed up section through approx.100 m of sedimentary rocks deposited in fluvial, deltaic, lacustrine, and eolian environments (Bradbury group and overlying Mount Sharp group). The Stimson formation lies unconformable over a lacustrine mudstone at the base of the Mount Sharp group and has been interpreted to be a cross-bedded sandstone of lithified eolian dunes. Mineralogy of the unaltered Stimson sandstone consists of plagioclase feldspar, pyroxenes, and magnetite with minor abundances of hematite, and Ca-sulfates (anhydrite, bassanite). Unaltered sandstone has a composition similar to the average Mars crustal composition. Alteration "halos" occur adjacent to fractures in the Stimson. Fluids passing through these fractures have altered the chemistry and mineralogy of the sandstone. Silicon and S enrichments and depletions in Al, Fe, Mg, Na, K, Ni and Mn suggest aqueous alteration in an open hydrologic system. Mineralogy of the altered Stimson is dominated by Ca-sulfates, Si-rich X-ray amorphous materials along with plagioclase feldspar, magnetite, and pyroxenes, but less abundant in the altered compared to the unaltered Stimson sandstone and lower pyroxene/plagioclase feldspar. The mineralogy and geochemistry of the altered sandstone suggest a complicated history with several (many?) episodes of aqueous alteration under a variety of environmental conditions (e.g., acidic, alkaline).

  18. burial customs and the pollution of death in ancient rome

    African Journals Online (AJOL)

    Acta Theologica Supplementum 7. 2005 we cannot be absolutely sure, it seems as if this type of behaviour was not seen as incurring the pollution of death (Bodel 2000:134, 148). Then there were those who were denied burial, and whose corpses were left on the sessorium to the mercy of the wild animals and the weather.

  19. The materiality of Funnelbeaker burial practice : Evidence from the microscope

    NARCIS (Netherlands)

    Gijn, van, A.L.; Marreiros J, Bicho N, Gibaja, J.F.


    Flint and amber artefacts from Dutch Funnelbeaker (3400-2900 cal BC) megaliths were examined from a biographical perspective, also involving microwear analysis. It is shown that both flint and amber contributed to the materiality of Funnelbeaker burial practices, which above all stressed the

  20. Scour around spherical bodies and self-burial

    DEFF Research Database (Denmark)

    Truelsen, Christoffer; Sumer, B. Mutlu; fredsøe, jørgen


    This paper summarizes the results of an experimental study on scour around spherical bodies and self-burial in steady current and in waves. The equilibrium scour depth below a fixed sphere in steady current for live-bed conditions was found to be S/D = O(O.3) D being the sphere diameter. The effe...

  1. Scale and distribution of marine carbonate burial dissolution pores

    Directory of Open Access Journals (Sweden)

    Anjiang Shen


    Full Text Available It is gradually accepted that porosity can be created in burial settings via dissolution by organic acid; TSR derived or hydrothermal fluids. The role of deep-buried carbonate reservoirs is becoming more and more important since the degree and difficulty in petroleum exploration of shallow strata are increasing. A profound understanding of the development scale and prediction of the deep-buried carbonate reservoirs is economically crucial. In addition to the formation mechanism, scale and distribution of burial dissolution pores in burial settings are focused on in recent studies. This paper is based on case studies of deep-buried (>4500 m carbonate reservoirs from the Tarim Basin and Sichuan Basin. Case studies mentioned includes dissolution simulation experiments proposes that an open system is of crucial importance in the development of large-scale burial dissolution pores, the distribution pattern of which is controlled by lithology, pre-existing porosity, and pore throat structures. These findings provided the basis for evaluation and prediction of deep-buried carbonate reservoirs.

  2. Cleanup Verification Package for the 118-F-6 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    H. M. Sulloway


    This cleanup verification package documents completion of remedial action for the 118-F-6 Burial Ground located in the 100-FR-2 Operable Unit of the 100-F Area on the Hanford Site. The trenches received waste from the 100-F Experimental Animal Farm, including animal manure, animal carcasses, laboratory waste, plastic, cardboard, metal, and concrete debris as well as a railroad tank car.

  3. Extending recognition of indigenous burial practices in Selomo v ...

    African Journals Online (AJOL)

    Burying deceased family members in familial gravesites close to the homestead of the living has been a well-established practice in Southern Africa for many centuries. In terms of indigenous cultural and religious norms proximate burials are essential for enabling ancestors to commune amongst themselves and with their ...

  4. Chemical and Mechanical processes during burial diagenesis of chalk

    DEFF Research Database (Denmark)

    Borre, Mai Kirstine; Lind, Ida


    Burial diagenesis of chalk is a combination of mechanical compaction and chemical recrystallization as well as cementation. We have predicted the characteristic trends in specific surface resulting from these processes. The specific surface is normally measured by nitrogen adsorption but is here...

  5. Gut contents as direct indicators for trophic relationships in the Cambrian marine ecosystem.

    Directory of Open Access Journals (Sweden)

    Jean Vannier

    Full Text Available Present-day ecosystems host a huge variety of organisms that interact and transfer mass and energy via a cascade of trophic levels. When and how this complex machinery was established remains largely unknown. Although exceptionally preserved biotas clearly show that Early Cambrian animals had already acquired functionalities that enabled them to exploit a wide range of food resources, there is scant direct evidence concerning their diet and exact trophic relationships. Here I describe the gut contents of Ottoia prolifica, an abundant priapulid worm from the middle Cambrian (Stage 5 Burgess Shale biota. I identify the undigested exoskeletal remains of a wide range of small invertebrates that lived at or near the water sediment interface such as hyolithids, brachiopods, different types of arthropods, polychaetes and wiwaxiids. This set of direct fossil evidence allows the first detailed reconstruction of the diet of a 505-million-year-old animal. Ottoia was a dietary generalist and had no strict feeding regime. It fed on both living individuals and decaying organic matter present in its habitat. The feeding behavior of Ottoia was remarkably simple, reduced to the transit of food through an eversible pharynx and a tubular gut with limited physical breakdown and no storage. The recognition of generalist feeding strategies, exemplified by Ottoia, reveals key-aspects of modern-style trophic complexity in the immediate aftermath of the Cambrian explosion. It also shows that the middle Cambrian ecosystem was already too complex to be understood in terms of simple linear dynamics and unique pathways.

  6. Carbonate rocks of Cambrian and Ordovician age in the Lancaster quadrangle, Pennsylvania (United States)

    Meisler, Harold; Becher, Albert E.


    Detailed mapping has shown that the carbonate rocks of Cambrian and Ordovician age in the Lancaster quadrangle, Pennsylvania, can be divided into 14 rock-stratigraphic units. These units are defined primarily by their relative proportions of limestone and dolomite. The oldest units, the Vintage, Kinzers, and Ledger Formations of Cambrian age, and the Conestoga Limestone of Ordovician age are retained in this report. The Zooks Corner Formation, of Cambrian age, a dolomite unit overlying the Ledger Dolomite, is named here for exposures along Conestoga Creek near the village of Zooks Corner. The Conococheague (Cambrian) and Beekmantown (Ordovician) Limestones, as mapped by earlier workers, have been elevated to group rank and subdivided into formations that are correlated with and named for geologic units in Lebanon and Berks Counties, Pa. These formations, from oldest to youngest, are the Buffalo Springs, Snitz Creek, Millbach, and Richland Formations of the Conococheague Group, and the Stonehenge, Bpler, and Ontelaunee Formations of the Beekmantown Group. The Annville and Myerstown Limestones, which are named for lithologically similar units in Dauphin and Lebanon Counties, Pa., overlie the Beekmantown Group in one small area in the quadrangle.

  7. Groundwater quality in the Cambrian-Ordovician aquifer system, midwestern United States (United States)

    Stackelberg, Paul E.


    Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water (Burow and Belitz, 2014). The Cambrian-Ordovician aquifer system constitutes one of the important areas being evaluated.

  8. Sarmatian Burials Near the Astanino Village in the Eastern Crimea

    Directory of Open Access Journals (Sweden)

    Kropotov Viktor Valeryevich


    Full Text Available The present article contains the materials of two Sarmatian burials that had been studied in 1966-1967 years by the Kerch expedition of Institute of Archeology of Academy of Sciences of Ukraine (the chief of expedition – A.M. Leskov in the Astanino village in the Eastern Crimea. These burials had been made on small depth in embankments of barrows of the bronze epoch, therefore it is not possible to track contours of funeral constructions. The dead were laid on their backs, heads turned to the North and the North-West. The utensils buried in the same tombs included two ceramic gray-clay pelikes, two gray-clay bowls, a red-gloss vessel, a red-clay pottery, a set of glass and cornelian beads, and the Egyptian faience beads. These things allow to exactly date the investigated complexes within the second half of the 1st century BC – the beginnings of the 1st century AD. The main distinctive characteristics of Early-Sarmatian burials of Northern Pontic region consist in the use of already existing barrows for burial places, orientations of the dead in the Northern sector, the insignificant depth of burials. Therefore published monuments should be also referred to them. A small number of such complexes with their distribution on the quite big territory between the Don and Dnepr rivers testify to the low density of the nomadic population at that time. The antique sources of the end of the 2nd – 1st centuries BC mention the presence of Roxolani in the given region. The described complexes supplement our poor knowledge of Sarmatian antiquities of the Eastern Crimea and specify the direct contacts of nomads of Northern Pontic region to the antique centers, in immediate proximity from which they had been located.

  9. 77 FR 35114 - Agency Information Collection (NCA PreNeed Burial Planning) Activity Under OMB Review (United States)


    ... AFFAIRS Agency Information Collection (NCA PreNeed Burial Planning) Activity Under OMB Review AGENCY... INFORMATION: Title: NCA PreNeed Burial Planning, VA Form 40-10007. OMB Control Number: 2900--New. Type of..., service members, and their eligible family members with planning for burial in a VA national cemetery...

  10. Funeral dress and textiles in 17th and 19th century burials in Ostrobothnia, Finland

    NARCIS (Netherlands)

    Lipkin, S.; Vajanto, K.; Kallio-Seppä, T.; Kuokkanen, T.; Niinimäki, S.; Väre, T.; van Bommel, M.; Grömer, K.; Pritchard, F.


    The 17th-19th-century burial materials from northern Ostrobothnia are studied in order to consider the value, origin and meaning of textiles especially in child burials. The focus is on the preservation, quality and dyes of burial textiles unearthed at the yard of Oulu Cathedral as well as the

  11. Dynamic triggering during rupture nucleation in sandstone (United States)

    Chanard, K.; Nicolas, A.; Latour, S.; Hatano, T.; Vinciguerra, S.; Schubnel, A.


    Fluid induced stress perturbations in the crust at seismogenic depths can be caused by various sources, such as deglaciation unloading, magmatic intrusion or fluid injection and withdrawal. Numbers of studies have robustly shown their link to earthquake triggering. However, the role of small periodic stress variations induced by solid earth and oceanic tides or seasonal hydrology in the seismic cycle, of the order of a few kPa, remains unclear. Indeed, the existence or absence of correlation between these loading phenomena and earthquakes have been equally proposed in the literature. To investigate this question, we performed a set of triaxial deformation experiments on porous water-saturated Fontainebleau sandstones. Rock samples were loaded by the combined action of steps of constant stress (creep), intended to simulate tectonic loading and small sinusoidal pore pressure variations with a range of amplitudes, analogous to tides or seasonal loading. All tests were conducted at a regulated temperature of 35C and a constant 35 MPa confining pressure. Our experimental results show that (1) pore pressure oscillations do not seem to influence the deformation rate at which the rock fails, (2) they correlate with acoustic emissions. Even more interestingly, we observe a progressive increase of the correlation coefficient in time as the rock approaches failure. The correlation coefficient is also sensitive to the amplitude of pore pressure oscillations as larger oscillations produce higher correlation levels. Finally, we show that, in the last hours of creep before failure, acoustic emissions occur significantly more when the pore pressure is at its lowest. This suggest that the correlation of small stress perturbations and acoustic emissions depend on the state stress of a rock and the amplitude of the perturbations and that emissions occur more likely when cracks are unclamped.

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

    Directory of Open Access Journals (Sweden)

    Xinfeng Ni


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

  13. The Cambrian-Ordovician rocks of Sonora, Mexico, and southern Arizona, southwestern margin of North America (Laurentia): chapter 35 (United States)

    Page, William R.; Harris, Alta C.; Repetski, John E.; Derby, James R.; Fritz, R.D.; Longacre, S.A.; Morgan, W.A.; Sternbach, C.A.


    Cambrian and Ordovician shelf, platform, and basin rocks are present in Sonora, Mexico, and southern Arizona and were deposited on the southwestern continental margin of North America (Laurentia). Cambrian and Ordovician rocks in Sonora, Mexico, are mostly exposed in scattered outcrops in the northern half of the state. Their discontinuous nature results from extensive Quaternary and Tertiary surficial cover, from Tertiary and Mesozoic granitic batholiths in western Sonora, and from widespread Tertiary volcanic deposits in the Sierra Madre Occidental in eastern Sonora. Cambrian and Ordovician shelf rocks were deposited as part of the the southern miogeocline on the southwestern continental margin of North America.

  14. Research on the Ediacaran and Cambrian of the Anti-Atlas and High Atlas Mountains, Morocco: An historical overview (United States)

    Debrenne, Françoise


    Two periods of geological research can be recognized in the Ediacaran and Cambrian of Morocco. The period 1917-1945 is represented by an exploration phase that led to numerous discoveries of Cambrian faunas overlying conformably or unconformably, thick, metamorphic, Precambrian formations. The Moroccan Geological Society (SGM) published numerous geological maps with notices and regional monographies. The second period (1948-1995) allowed erection of detailed litho- and biostratigraphic sketches for stratigraphic subdivisions, among which the proposal of alternative (radiometric and chemostratigraphic) methods to precisely locate the Precambrian-Cambrian boundary in Morocco.

  15. Uranium isotopes distinguish two geochemically distinct stages during the later Cambrian SPICE event

    DEFF Research Database (Denmark)

    Dahl, Tais Wittchen; Boyle, Richard A.; Canfield, Donald E.


    Anoxic marine zones were common in early Paleozoic oceans (542-400 Ma), and present a potential link to atmospheric pO2 via feedbacks linking global marine phosphorous recycling, primary production and organic carbon burial. Uranium (U) isotopes in carbonate rocks track the extent of ocean anoxia...... event encompasses two different stages of elevated organic carbon and pyrite burial maintained by high nutrient fluxes to the ocean, and potentially sustained by internal marine geochemical feedbacks....

  16. Late Sarmatian Elite Military Burial From the Southern Urals

    Directory of Open Access Journals (Sweden)

    Krivosheev Mikhail Vasilyevich


    Full Text Available The article is devoted to the burial of a warrior of Late Sarmatian time from the Southern Urals. The complex from mound no. 4 of the burial mound Taksai I is distinguished by large size of barrow and grave. The reconstructed height of the mound was less than 2 meters. The depth of the burial pit was more than 3 meters. For Late Sarmatian culture such dimensions of sepulchral structures are unique. Under the mound the ritual platform from mainland soil was discovered. The found inventory of a warrior-rider included: horse bridle, a set of bladed weapons consisting of a long sword, dagger and knife, as well as a small bronze cauldron. Analysis of inventory allows us to date this burial to the second half of the 3rd century A.D. This burial belongs to an elite funerary complexes of Late Sarmatian culture and is a burial of professional warriors. This social stratum was formed in Late Sarmatian society at the end of the 2nd - first half of the 3rd century A.D. Most of these graves are dating back to the first half of the 3rd century A.D and were found in the Low Don and in the Volga region. The situation in these regions changed in that period due to the invasion of the tribes of the North-Caucasian origin. Their occurrence is associated with the destruction of the Tanais in the Lower Don region and the spread of graves in the T-shaped catacombs in the steppe monuments. The tradition of burying warriors-horsemen of high social status almost disappears in the Volga-Don steppes after the middle of 3rd century A.D. In the Southern Urals where these processes had an indirect influence, the existence of traditional hierarchies of Late Sarmatian society could continue until the end of the 3rd century A.D. Among the parts of a horse bridle the researchers discovered bronze B-shape buckle. These buckles are widely distributed in the 4th-5th centuries A.D. in the basin of the Kama river and the Danube river. The found buckle is the earliest currently known

  17. Revisiting Field Burial by Accretion onto Neutron Stars (United States)

    Mukherjee, Dipanjan


    The surface magnetic field strength of millisecond pulsars (MSPs) is found to be about 4 orders of magnitude lower than that of garden variety radio pulsars (with a spin of {˜ }0.5-5 s and B{˜ }10^{12} G). The exact mechanism of the apparent reduction of field strength in MSPs is still a subject of debate. One of the proposed mechanisms is burial of the surface magnetic field under matter accreted from a companion. In this article we review the recent work on magnetic confinement of accreted matter on neutron stars poles. We present the solutions of the magneto-static equations with a more accurate equation of state of the magnetically confined plasma and discuss its implications for the field burial mechanism.

  18. The impact of sediment burial and erosion on seagrasses: A review (United States)

    Cabaço, Susana; Santos, Rui; Duarte, Carlos M.


    The available information from experimental and descriptive studies on the effects of sediment burial and erosion on seagrasses was compiled to synthesize the information regarding the species-specific impacts and to relate them to plant characteristics. Burial thresholds (i.e. the burial levels causing 50% and 100% shoot mortality) and mortality-burial curves were estimated for the 15 seagrass species where the effects of experimental burial have been tested. All the species investigated reached 50% shoot mortality at burial levels ranging from 2 cm ( Halophila ovalis) to 19.5 cm ( Posidonia australis). P. australis was the most tolerant seagrass species to burial, while Thalassia testudinum was the most tolerant species to erosion. The relationships among plant size, growth, biomass and density with burial thresholds were examined. There were significant relationships between the burial thresholds and the shoot mass, the rhizome diameter, the aboveground biomass, the horizontal rhizome elongation and the leaf length of seagrass species. The leaf size and the rhizome diameter are the best predictors of the capacity of seagrasses to withstand burial. The burial thresholds estimated for seagrass species were in many cases in agreement with the burial impacts described by field observations (bioturbation), while in some cases was related to the species long-term colonization capacity (dune migration). Most human-induced impacts result in important changes of the sedimentary environment, with permanent negative effects on seagrass meadows (regression and complete destruction), whereas natural events, whether extreme (hurricane) or regular (dune migration), allow the recovery and/or adaptation of seagrasses to the burial/erosion sediment dynamics. The extent of the effects of burial and erosion on seagrasses is species-specific and strongly size-dependent.

  19. Implications of burial alterations on luminescence dating of archaeological ceramics


    Zacharias, N.; Buxeda i Garrigós, Jaume; ;H. Mommsen; Schwedt, A.; Kilikoglou, V.


    Recent mineralogical studies on archaeological pottery samples report significant variations in alkali metal concentrations due to environmental alterations during burial. Here we examine the effects of potassium (K) leaching on luminescence dating. The effect on the estimation of the dose rate is studied by considering four models of leaching (exponential, linear, early and late) and their impact on fine- and coarse-grain dating are calculated. The modeling approaches are applied to two case...

  20. Pore microgeometry analysis in low-resistivity sandstone reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Cerepi, Adrian [Institut EGID-Bordeaux 3, Universite Michel de Montaigne, 1, allee F. Daguin, 33607, cedex Pessac (France); Durand, Claudine; Brosse, Etienne [Institut Francais du Petrole, 1 and 4 avenue de Bois Preau, 92852, cedex Rueil-Malmaison (France)


    The objective of this work is to analyse the pore microgeometry and its effect on petrophysical properties in six low-resistivity sandstone reservoirs by combining a 2D quantitative petrographic image analysis (PIA) and 3D petrophysical tools. The classic petrophysical tools enable the measurement of different classic reservoir properties such as specific surface area, average pore diameter, pore size distribution, macroporosity and microporosity, capillary pressure versus saturation, pore chamber-pore throat diameter ratio, electrical properties and permeability. The petrographic image analysis quantifies pore microgeometry in more than four orders of magnitude, from submicron to millimeter scale. Chloritic low-resistivity sandstones show dual porosity structure defined as chloritic texture. The pore microgeometrical parameters measured by petrographic image analysis allow one to model different reservoir properties such as capillary pressure, permeability and electrical behaviour. The results obtained in these models show that pore microgeometry plays an important role in the physical properties of low-resistivity sandstone reservoirs.

  1. Interrelationship of age and diet in Romania's oldest human burial (United States)

    Bonsall, Clive; Boroneanţ, Adina; Soficaru, Andrei; McSweeney, Kathleen; Higham, Tom; Miriţoiu, Nicolae; Pickard, Catriona; Cook, Gordon


    In 1968, excavations in the Climente II cave in the Iron Gates gorge of the River Danube in southwest Romania unearthed the skeleton of an adult male. The burial was assumed to be of Late Pleistocene age because of the presence of Late Upper Palaeolithic (LUP) artefacts in the cave. However, there was no strong supporting stratigraphic evidence, and the body position is reminiscent of Early Neolithic burial practice in the region. Here, we report the results of radiocarbon and stable isotope analyses of the Climente II skeleton, which show that the skeleton dates to the Bølling-Allerød Interstadial ~14,500 cal BP. This is several millennia older than any previously dated human remains from the Iron Gates region and confirms its status as the oldest known burial from Romania. The stable isotope results indicate a diet with an emphasis on aquatic resources, contrary to the commonly held view that the LUP inhabitants of the Iron Gates subsisted mainly by hunting large land mammals.

  2. Ground resistance influences lizard burial in dry and wet sand (United States)

    Sharpe, Sarah; Kuckuk, Robyn; Goldman, Daniel


    Many terrestrial animals move within soil in which water content can vary, and little is known about how water content affects locomotor performance. To investigate the effect of water content on burial, we created controlled dry and wet substrates. We used 0.3 mm glass particles and varied water content W, the mass of water to mass of dry loosely packed sand. Drag force on a submerged 1.6 cm diameter rod increased by a factor of 4 as W increased from 0 to 0.03, after which force increases were small. Drag force in wet media periodically fluctuated with time and corresponded with surface fracturing. We characterized how W affected burial performance and strategy of a generalist burrower, the ocellated skink lizard (Chalcides ocellatus). High speed x-ray imaging was used to measure head, body and limb kinematics in substrates with W= 0 and W= 0.03. In both states during burial the body was maintained in a curved posture and the animal moved using a start-stop motion. During movement, the head oscillated and the forelimb on the convex side of the body was used to push the animal forward. Both speed and angular excursion of the head oscillation decreased in the W= 0.03 state. The differences in locomotion were attributed to the changing resistance force within the media.

  3. Disc-shaped fossils resembling porpitids or eldonids from the early Cambrian (Series 2: Stage 4) of western USA


    Lieberman, Bruce S.; Kurkewicz, Richard; Shinogle, Heather; Kimmig, Julien; MacGabhann, Breand?n Anraoi


    The morphology and affinities of newly discovered disc-shaped, soft-bodied fossils from the early Cambrian (Series 2: Stage 4, Dyeran) Carrara Formation are discussed. These specimens show some similarity to the Ordovician Discophyllum Hall, 1847; traditionally this taxon had been treated as a fossil porpitid. However, recently it has instead been referred to as another clade, the eldonids, which includes the enigmatic Eldonia Walcott, 1911 that was originally described from the Cambrian Burg...

  4. The effect of hot water injection on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Haugwitz, Christian; Jacobsen, Peter Sally Munch


    Seasonal energy storage can be achieved by hot water injection in geothermal sandstone aquifers. We present an analysis of literature data in combination with new short-term flow through permeability experiments in order to address physical and physico-chemical mechanisms that can alter permeabil......Seasonal energy storage can be achieved by hot water injection in geothermal sandstone aquifers. We present an analysis of literature data in combination with new short-term flow through permeability experiments in order to address physical and physico-chemical mechanisms that can alter...

  5. Roughness of sandstone fracture surfaces: Profilometry and shadow length investigations


    Boffa, Jean-Marc; Allain, C.; Chertcoff, R.; Hulin, Jean-Pierre; Plouraboué, Franck; Roux, Stéphane


    The geometrical properties of fractured sandstone surfaces were studied by measuring the length distribution of the shadows appearing under grazing illumination. Three distinct domains of variation were found: at short length scales a cut-off of self-affinity is observed due to the inter-granular rupture of sandstones, at long length scales, the number of shadows falls off very rapidly because of the non-zero illumination angle and of the finite roughness amplitude. Finally, in the intermediate do...

  6. Natural and Laboratory-Induced Compaction Bands in Aztec Sandstone (United States)

    Haimson, B. C.; Lee, H.


    The Aztec sandstone used in this research is from the Valley of Fire State Park area, Nevada. This Jurassic aeolian sandstone is extremely weak (uniaxial compressive strength of 1-2 MPa); porosity averages 26%; grains are subrounded and have a bimodal size distribution (0.1 mm and 0.5 mm); its mineral composition (K. Sternlof, personal comm.) is 93% quartz, 5% k-spar, and 2% kaolinite, Fe carbonate and others; grain bonding is primarily through suturing. Sternlof et al. (EOS, November, 2001) observed substantial exposure of mainly compactive deformation bands in the Aztec sandstone. We studied an SEM image of a compaction band found in a hand sample of the Aztec sandstone. We also conducted a drilling test in a 130x130x180 mm prismatic specimen subjected to a preset far-field true triaxial stress condition (\\sigmah = 15 MPa, \\sigmav = 25 MPa, \\sigmaH = 40 MPa). Drilling of a 20 mm dia. vertical hole created a long fracture-like thin tabular breakout along the \\sigmah springline and perpendicular to \\sigmaH direction. SEM analysis of the zones ahead of the breakout tips revealed narrow bands of presumed debonded intact grains interspersed with grain fragments. We infer that the fragments were formed from multiple splitting or crushing of compacted grains in the band of high compressive stress concentration developed along the \\sigmah springline. SEM images away from the breakout tip surroundings showed no such fragments. SEM study of the natural compaction band showed a similar arrangement of mainly intact grains surrounded by grain fragments. Using the Optimas optical software package, we found the percentage of pore area within the band ahead of the breakout tips to average 17%; outside of this zone it was 23%. In the natural compaction band pore area occupied 8.5% of the band; in the host rock adjacent to the compaction band it averaged 19%. These readings strongly suggest porosity reduction due to compaction in both cases. The close resemblance between the

  7. A chancelloriid-like metazoan from the early Cambrian Chengjiang Lagerstätte, China (United States)

    Hou, Xianguang; Williams, Mark; Siveter, David J.; Siveter, Derek J.; Gabbott, Sarah; Holwell, David; Harvey, Thomas H. P.


    Nidelric pugio gen. et sp. nov. from the Cambrian Series 2 Heilinpu Formation, Chengjiang Lagerstätte, Yunnan Province, China, is an ovoid, sac-like metazoan that bears single-element spines on its surface. N. pugio shows no trace of a gut, coelom, anterior differentiation, appendages, or internal organs that would suggest a bilateral body plan. Instead, the sac-like morphology invites comparison with the radially symmetrical chancelloriids. However, the single-element spines of N. pugio are atypical of the complex multi-element spine rosettes borne by most chancelloriids and N. pugio may signal the ancestral chancelloriid state, in which the spines had not yet fused. Alternatively, N. pugio may represent a group of radial metazoans that are discrete from chancelloriids. Whatever its precise phylogenetic position, N. pugio expands the known disparity of Cambrian scleritome-bearing animals, and provides a new model for reconstructing scleritomes from isolated microfossils.

  8. Cambrian spiral-plated echinoderms from Gondwana reveal the earliest pentaradial body plan. (United States)

    Smith, Andrew B; Zamora, Samuel


    Echinoderms are unique among animal phyla in having a pentaradial body plan, and their fossil record provides critical data on how this novel organization came about by revealing intermediate stages. Here, we report a spiral-plated animal from the early Cambrian of Morocco that is the most primitive pentaradial echinoderm yet discovered. It is intermediate between helicoplacoids (a bizarre group of spiral-bodied echinoderms) and crown-group pentaradiate echinoderms. By filling an important gap, this fossil reveals the common pattern that underpins the body plans of the two major echinoderm clades (pelmatozoans and eleutherozoans), showing that differential growth played an important role in their divergence. It also adds to the striking disparity of novel body plans appearing in the Cambrian explosion.

  9. Burial Duration and Frequency Influences Resilience of Differing Propagule Types in a Subtidal Seagrass, Posidonia australis.

    Directory of Open Access Journals (Sweden)

    Marnie L Campbell

    Full Text Available Sedimentation that leads to periodic, and often prolonged, burial events is becoming more common on the world's coastlines as human populations expand and create urbanised marine environments. Different seagrass species react differently to sediment burial but many species in the southern hemisphere are yet to be examined. How seagrasses react to burial has restoration implications. There is a need to critically assess seagrass transplant propagule responses to periodic (pulse and prolonged (press burial events before selecting the most appropriate species, transplant propagule, and transplant site. In my study, mesocosm experiments, coupled with field measurements were used to assess how sexual (seedlings and vegetative (sprigs propagules of Posidonia australis responded to pulse and press burial events. Seedlings were highly susceptible to burial (both pulse and press, with no survival at the end of the experimental period. In contrast, rhizome growth in vegetative propagules was stimulated by pulse burial, although press burial events resulted in mortality. The implication for Posidonia australis restoration efforts in areas where burial is periodic, was that vegetative propagules are optimal transplant units, in comparison to seedlings. Press burial however, renders a transplant site sub-optimal for both seedling and sprig transplants.

  10. Burial Duration and Frequency Influences Resilience of Differing Propagule Types in a Subtidal Seagrass, Posidonia australis. (United States)

    Campbell, Marnie L


    Sedimentation that leads to periodic, and often prolonged, burial events is becoming more common on the world's coastlines as human populations expand and create urbanised marine environments. Different seagrass species react differently to sediment burial but many species in the southern hemisphere are yet to be examined. How seagrasses react to burial has restoration implications. There is a need to critically assess seagrass transplant propagule responses to periodic (pulse) and prolonged (press) burial events before selecting the most appropriate species, transplant propagule, and transplant site. In my study, mesocosm experiments, coupled with field measurements were used to assess how sexual (seedlings) and vegetative (sprigs) propagules of Posidonia australis responded to pulse and press burial events. Seedlings were highly susceptible to burial (both pulse and press), with no survival at the end of the experimental period. In contrast, rhizome growth in vegetative propagules was stimulated by pulse burial, although press burial events resulted in mortality. The implication for Posidonia australis restoration efforts in areas where burial is periodic, was that vegetative propagules are optimal transplant units, in comparison to seedlings. Press burial however, renders a transplant site sub-optimal for both seedling and sprig transplants.

  11. Formation of the 'Great Unconformity' as a trigger for the Cambrian explosion. (United States)

    Peters, Shanan E; Gaines, Robert R


    The transition between the Proterozoic and Phanerozoic eons, beginning 542 million years (Myr) ago, is distinguished by the diversification of multicellular animals and by their acquisition of mineralized skeletons during the Cambrian period. Considerable progress has been made in documenting and more precisely correlating biotic patterns in the Neoproterozoic-Cambrian fossil record with geochemical and physical environmental perturbations, but the mechanisms responsible for those perturbations remain uncertain. Here we use new stratigraphic and geochemical data to show that early Palaeozoic marine sediments deposited approximately 540-480 Myr ago record both an expansion in the area of shallow epicontinental seas and anomalous patterns of chemical sedimentation that are indicative of increased oceanic alkalinity and enhanced chemical weathering of continental crust. These geochemical conditions were caused by a protracted period of widespread continental denudation during the Neoproterozoic followed by extensive physical reworking of soil, regolith and basement rock during the first continental-scale marine transgression of the Phanerozoic. The resultant globally occurring stratigraphic surface, which in most regions separates continental crystalline basement rock from much younger Cambrian shallow marine sedimentary deposits, is known as the Great Unconformity. Although Darwin and others have interpreted this widespread hiatus in sedimentation on the continents as a failure of the geologic record, this palaeogeomorphic surface represents a unique physical environmental boundary condition that affected seawater chemistry during a time of profound expansion of shallow marine habitats. Thus, the formation of the Great Unconformity may have been an environmental trigger for the evolution of biomineralization and the 'Cambrian explosion' of ecologic and taxonomic diversity following the Neoproterozoic emergence of animals.

  12. Cambrian stem-group annelids and a metameric origin of the annelid head. (United States)

    Parry, Luke; Vinther, Jakob; Edgecombe, Gregory D


    The oldest fossil annelids come from the Early Cambrian Sirius Passet and Guanshan biotas and Middle Cambrian Burgess Shale. While these are among the best preserved polychaete fossils, their relationship to living taxa is contentious, having been interpreted either as members of extant clades or as a grade outside the crown group. New morphological observations from five Cambrian species include the oldest polychaete with head appendages, a new specimen of Pygocirrus from Sirius Passet, and an undescribed form from the Burgess Shale. We propose that the palps of Canadia are on an anterior segment bearing neuropodia and that the head of Phragmochaeta is formed of a segment bearing biramous parapodia and chaetae. The unusual anatomy of these taxa suggests that the head is not differentiated into a prostomium and peristomium, that palps are derived from a modified parapodium and that the annelid head was originally a parapodium-bearing segment. Canadia, Phragmochaeta and the Marble Canyon annelid share the presence of protective notochaetae, interpreted as a primitive character state subsequently lost in Pygocirrus and Burgessochaeta, in which the head is clearly differentiated from the trunk. © 2015 The Authors.

  13. Life cycle and morphology of a cambrian stem-lineage loriciferan.

    Directory of Open Access Journals (Sweden)

    John S Peel

    Full Text Available Cycloneuralians form a rich and diverse element within Cambrian assemblages of exceptionally preserved fossils. Most resemble priapulid worms whereas other Cycloneuralia (Nematoda, Nematomorpha, Kinorhyncha, Loricifera, well known at the present day, have little or no fossil record. First reports of Sirilorica Peel, 2010 from the lower Cambrian Sirius Passet fauna of North Greenland described a tubular lorica covering the abdomen and part of a well developed introvert with a circlet of 6 grasping denticles near the lorica. The introvert is now known to terminate in a narrow mouth tube, while a conical anal field is also developed. Broad muscular bands between the plates in the lorica indicate that it was capable of movement by rhythmic expansion and contraction of the lorica. Sirilorica is regarded as a macrobenthic member of the stem-lineage of the miniaturised, interstitial, present day Loricifera. Like loriciferans, Sirilorica is now known to have grown by moulting. Evidence of the life cycle of Sirilorica is described, including a large post-larval stage and probably an initial larva similar to that of the middle Cambrian fossil Orstenoloricusshergoldii.

  14. The controversial "Cambrian" fossils of the Vindhyan are real but more than a billion years older. (United States)

    Bengtson, Stefan; Belivanova, Veneta; Rasmussen, Birger; Whitehouse, Martin


    The age of the Vindhyan sedimentary basin in central India is controversial, because geochronology indicating early Proterozoic ages clashes with reports of Cambrian fossils. We present here an integrated paleontologic-geochronologic investigation to resolve this conundrum. New sampling of Lower Vindhyan phosphoritic stromatolitic dolomites from the northern flank of the Vindhyans confirms the presence of fossils most closely resembling those found elsewhere in Cambrian deposits: annulated tubes, embryo-like globules with polygonal surface pattern, and filamentous and coccoidal microbial fabrics similar to Girvanella and Renalcis. None of the fossils, however, can be ascribed to uniquely Cambrian or Ediacaran taxa. Indeed, the embryo-like globules are not interpreted as fossils at all but as former gas bubbles trapped in mucus-rich cyanobacterial mats. Direct dating of the same fossiliferous phosphorite yielded a Pb-Pb isochron of 1,650 +/- 89 (2sigma) million years ago, confirming the Paleoproterozoic age of the fossils. New U-Pb geochronology of zircons from tuffaceous mudrocks in the Lower Vindhyan Porcellanite Formation on the southern flank of the Vindhyans give comparable ages. The Vindhyan phosphorites provide a window of 3-dimensionally preserved Paleoproterozoic fossils resembling filamentous and coccoidal cyanobacteria and filamentous eukaryotic algae, as well as problematic forms. Like Neoproterozoic phosphorites a billion years later, the Vindhyan deposits offer important new insights into the nature and diversity of life, and in particular, the early evolution of multicellular eukaryotes.

  15. Self-regulation of trilobite diversity in Murero (middle Cambrian, Spain) due to compensatory extinction

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Villalta, J.S.


    As species accumulate in a community, competition for available ecospace is expected to prevent the addition of new species and to facilitate species extinction, thus producing a dynamic equilibrium of diversity. This mechanism remains under debate since its empirical support comes mainly from indirect or partial evidence, with very few direct tests at the species level. Here a new method is described to detect the presence of selfregulation feedbacks between species richness and turnover rates. It consists of Monte Carlo simulations which randomize the distribution of species ranges among stratigraphic intervals, providing predictions which allow the detection of genuine self-regulation feedbacks in the real data. Since the simulations include any potential bias due to preservation, sampling, or change in depositional environment, and these biases would also affect the real dataset, they are thus ruled out as explanations for any difference found. This method is applied to one of the best known fossiliferous sequences worldwide, the Rambla de Valdemiedes in Murero (RV1 section, middle Cambrian, Spain), a classic locality that has been studied for more than 150 years and which stands out due to its excellent sampling density, continuous deposition, and homogeneous fossil preservation. The results show that trilobite species richness was self-regulated due to positive feedback with extinction rate, which implies that compensatory extinction regulated this fauna in spite of the on-going Cambrian radiation. The lack of evidence of any origination feedback suggests ecological opportunities were not limiting for new species to colonize this Cambrian community. (Author)

  16. Cambrian stem-group annelids and a metameric origin of the annelid head (United States)

    Parry, Luke; Vinther, Jakob; Edgecombe, Gregory D.


    The oldest fossil annelids come from the Early Cambrian Sirius Passet and Guanshan biotas and Middle Cambrian Burgess Shale. While these are among the best preserved polychaete fossils, their relationship to living taxa is contentious, having been interpreted either as members of extant clades or as a grade outside the crown group. New morphological observations from five Cambrian species include the oldest polychaete with head appendages, a new specimen of Pygocirrus from Sirius Passet, and an undescribed form from the Burgess Shale. We propose that the palps of Canadia are on an anterior segment bearing neuropodia and that the head of Phragmochaeta is formed of a segment bearing biramous parapodia and chaetae. The unusual anatomy of these taxa suggests that the head is not differentiated into a prostomium and peristomium, that palps are derived from a modified parapodium and that the annelid head was originally a parapodium-bearing segment. Canadia, Phragmochaeta and the Marble Canyon annelid share the presence of protective notochaetae, interpreted as a primitive character state subsequently lost in Pygocirrus and Burgessochaeta, in which the head is clearly differentiated from the trunk. PMID:26445984

  17. Geochemistry and diagenetic history of the Ordovician Lower Head Formation sandstones, western Newfoundland, Canada

    National Research Council Canada - National Science Library

    Azmy, Karem; Conliffe, James; Blamey, Nigel J.F


    ...) comprises siltstones with very fine grained to fine-grained sandstones. Petrography confirms that these sandstones are matrix rich, essentially wackes, with detrital minerals including quartz, feldspar, biotite, and numerous accessory minerals...

  18. Trilobites from the Middle Ordovician Stairway Sandstone, Amadeus Basin, central Australia

    DEFF Research Database (Denmark)

    Jakobsen, Kristian Grube; Nielsen, Arne Thorshøj; Harper, David Alexander Taylor


    During the Middle Ordovician (Darriwilian) sandstones and siltstones were deposited in the epicontinental Larapintine Sea, which covered large parts of central Australia. The Darriwilian Stairway Sandstone has, for the first time, been sampled stratigraphically for macrofossils to track marine...

  19. African/Amazonian Proterozoic correlations of Iberia: A detrital zircon U-Pb study of early Cambrian conglomerates from the Sierra de la Demanda (northern Spain) (United States)

    ÁBalos, B.; Gil Ibarguchi, J. I.; SáNchez-Lorda, M. E.; Paquette, J. L.


    Unfoliated conglomerates define the base of an Early Cambrian transgressive system tract in the Sierra de la Demanda. Correlations allow us to bracket the corresponding sechron between 532 Ma and 520-521 Ma. These conglomerates contain sandstone and metamorphic quartzite pebbles carrying detrital tourmaline, rutile and zircon grains of plutonic or medium- to high-grade metamorphic derivation. Zircon detrital grains exhibit concordant or sub-concordant U/Pb ages clustered in various groups, including Neoarchean (2.52-2.56 Ga), Paleoproterozoic (1.71-2.02 Ga), and Mesoproterozoic (1.47 and ca. 1.1-1.0 Ga), the latter representative of orogenic magmatism related to Rodinia supercontinental assembly. The Neoproterozoic is represented by concordant ages in the range 750-880 Ma and by Cryogenian discordant ages. Ediacaran zircons cluster in two subsets ranging between 590 and 680 Ma and 560-585 Ma, both including several concordant ages. They reflect formation of juvenile crust in magmatic arc and back-arc basin settings. Zircon ages younger than 520-525 Ma postdate the depositional age of the conglomerate and may represent Hercynian overprinting. Bibliographic data overlooked in other provenance studies indicate that Mesoproterozoic relics as those presented here should no longer be considered of exotic origin with respect to a Gondwanan (West African) affinity of the Neoproterozoic to early Paleozoic of Iberia. The proposed source area, the "Ebro Massif" of central-north Iberia, currently is concealed under a kilometer-thick Paleozoic or younger cover. Its tectonic organization would compare to that of the North African or Amazonian cratons (including Mesoproterozoic components), rather than to the Neoproterozoic arc settings described in northwest and southwest Iberia.

  20. paleomagnetic dating of the enticho sandstone at negash locality

    African Journals Online (AJOL)


    origin and interpreted as the Characteristic Remanent Magnetization (ChRM). Directions of magnetizations and site-mean directions in the in-situ .... for representative specimens from Enticho Sandstone at Negash. (B) AF demagnetization curve of the IRM experiment in A; the corresponding specimen names are given.

  1. INTRODUCTION Sandstone beds within Auchi locality are the ...

    African Journals Online (AJOL)

    Geological Survey report described the lithostratigraphic unit as False bedded Sandstone. Reyment (1965) ... Department of Applied Geology,. Federal University of Technology Akure. (Corresponding Author: ...... Oluyemi, E.A. and Olabanji, I.O.. Heavy Metals Determination in Some Species of Frozen. Fish Sold at Ile-Ife ...

  2. Diagenesis, provenance and depositional environments of the Bunter Sandstone Formation

    DEFF Research Database (Denmark)

    Olivarius, Mette; Weibel, Rikke; Friis, Henrik

    The Bunter Sandstone Formation in the northern North German Basin has large geothermal potential with high porosity and permeability (generally >15% and >100 mD, respectively) and with pore fluid temperatures that are adequate for geothermal energy production (c. 55–60˚C). A combined investigation...

  3. Influence of fluvial sandstone architecture on geothermal energy production

    NARCIS (Netherlands)

    Willems, C.J.L.; Maghami Nick, Hamidreza M.; Weltje, G.J.; Donselaar, M.E.; Bruhn, D.F.


    Fluvial sandstone reservoirs composed of stacked meander belts are considered as potential geothermal resources in the Netherlands. Net-to-gross, orientation and stacking pattern of the channel belts is of major importance for the connectivity between the injection and production well in such

  4. Diagenesis and mass transfer between Permo-Triassic sandstones ...

    African Journals Online (AJOL)

    samples were examined under a JEOL 6400 scanning electron microscope equipped with energy dispersive X-ray ... that feldspar overgrowths and crystals are widely distributed throughout the sandstones, and the interbedded ... extensive precipitation of calcite (C) crystals in sandy facies that interbedded within the Mercia.

  5. Provenance of the Late Neogene Siwalik sandstone, Kumaun ...

    Indian Academy of Sciences (India)

    An understanding about lithology, tectonics and unroofing history of provenance is mostly drawn from ... history of Late Neogene Siwalik sandstone of the ...... and Tibet: Mountain Roots to Mountain Tops (eds). Macfarlane A, Sorkhabi R B and Quade (Colorado: Boulder), J. Geol. Soc. Am. Spec. Paper, pp. 239–256.

  6. Provenance of sandstone on the western flank of Anambra Basin ...

    African Journals Online (AJOL)

    The localities are in the western flank of the Anambra basin, southwestern Nigeria. Petrographic study shows that the sandstone deposits are composed of variable amounts of quartz, feldspars and lithic fragments with minor occurrence of authigenic silica and chlorite cements. Quartz is the predominant detrital mineral in all ...

  7. Comparison of authigenic minerals in sandstones and interbedded ...

    African Journals Online (AJOL)

    Mechanically infiltrated clays, grain-coating clay/hematite, quartz and feldspar overgrowths, carbonate cements and pore-filling and pore-lining clay minerals that precipitated in the sandy facies also precipitated in the fine-grained sediments. The abundance of authigenic minerals in decreasing order include: sandstone ...

  8. comparison of authigenic minerals in sandstones and interbedded

    African Journals Online (AJOL)


    shaly facies dominated by detrital clay, carbonate, quartz and feldspars framework grains. Authigenic minerals such as quartz, albite and K-feldspar are absent in the shaly facies, possibly related to early destruction of porosity. The lacustrine sandstones, siltstones and mudstones followed marine diagenetic trend, whereas ...

  9. Sedimentological characteristics of Ajali sandstone in the Benin ...

    African Journals Online (AJOL)

    The major framework composition is Q95.6 F3.2 L1.2 which classifies the sandstone as Quartz arenite. Non-opaque heavy minerals constitute 13% of the entire heavy mineral suite of which ZTR index is 87%. The grains are texturally immature as depicted by their subangular edges but mineralogically mature in terms of ...

  10. Origin of carbonate cements in Cretaceous sandstones from lower ...

    African Journals Online (AJOL)

    Beds of authigenic carbonates were identified from three Cretaceous lithostratigraphic units of the Lower Benue Trough, Nigeria. Three carbonate lithologies were recognized by petrographic analysis in the study area. Carbonate-cemented sandstones are dominated by ferroan calcite cements with subordinate amount of ...

  11. diagenesis and mass transfer between permo-triassic sandstones ...

    African Journals Online (AJOL)

    Beds of siltstone, mudstone and shale are interbedded in the Permo-Triassic sandstones of the Ulster Basin, UK, at different stratigraphic levels. The paragenetic sequences of authigenic minerals both in the sandy and fine-grained sediments (mudstones and siltstones) indicate red bed diagenetic trend. Abundant ...

  12. Albitization in the Inkisi Sandstones, Republic of Congo ...

    African Journals Online (AJOL)

    In this paper, we present the process of albitization in the context of an African sedimentary basin, in particular the Neoproterozoic to Palaeozoic arkosic sandstones of the Niari basin in the Republic of Congo. Differents faciès, mineral parageneses associated, chemical compositions of these albitizations are presented.

  13. INTRODUCTION Sandstone beds within Auchi locality are the ...

    African Journals Online (AJOL)

    mineralogical compositions in order to establish the depositional history in the extreme western margin of the formation. SEDIMENTOLOGICAL CHARACTERISTICS OF AJALI SANDSTONE IN THE. BENIN FLANK OF ANAMBRA BASIN, NIGERIA. Adekoya, J.A., Aluko, A.F. and Opeloye, S.A.. Department of Applied Geology,.

  14. Petrography and geochemistry of turonian eze-aku sandstone ...

    African Journals Online (AJOL)

    An integrated petrographic and geochemical study of the Turonian sandstone of Eze-Aku Formation exposed within the southern portion of the Benue trough, was undertaken to infer ... Tectonic setting discrimination diagrams based on major elements suggest a continental block provenance in a passive continental margin.

  15. GPR and bulk ground resistivity surveys in graveyards: locating unmarked burials in contrasting soil types. (United States)

    Hansen, James D; Pringle, Jamie K; Goodwin, Jon


    With graveyards and cemeteries globally being increasingly designated as full, there is a growing need to identify unmarked burial positions to find burial space or exhume and re-inter if necessary. In some countries, for example the U.S. and U.K., burial sites are not usually re-used; however, most graveyard and cemetery records do not have maps of positions. One non-invasive detection method is near-surface geophysics, but there has been a lack of research to-date on optimal methods and/or equipment configuration. This paper presents three case studies in contrasting burial environments, soil types, burial styles and ages in the U.K. Geophysical survey results reveal unmarked burials could be effectively identified from these case studies that were not uniform or predicted using 225 MHz frequency antennae GPR 2D 0.5 m spaced profiles. Bulk ground electrical surveys, rarely used for unmarked burials, revealed 1 m probe spacings were optimal compared to 0.5 m, with datasets needing 3D detrending to reveal burial positions. Results were variable depending upon soil type; in very coarse soils GPR was optimal; whereas resistivity was optimal in clay-rich soils and both were optimal in sandy and black earth soils. Archaeological excavations revealed unmarked burials, extra/missing individuals from parish records and a variety of burial styles from isolated, brick-lined, to vertically stacked individuals. Study results, evidence unmarked burial targets were significantly different from clandestine burials of murder victims which are used as analogues. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. Closure Plan for Active Low Level Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    SKELLY, W.A.


    This plan has been prepared in response to direction from the U.S. Department of Energy. The purpose of the plan is to define approaches that will be implemented to ensure protection of the public and the environment when active Low-Level Burial Grounds (LLBGs) at the Hanford Site are closed. Performance assessments for active burial grounds in the 200 East and West 200 Areas provide current estimates of potential environmental contamination and doses to the ''maximum exposed individual'' from burial ground operation and closure and compare dose estimates to performance objective dose limits for the facilities. This is an Operational Closure Plan. The intent of the guidance in DOE Order 435.1 is that this plan will be a living document, like the facility performance assessments, and will be revised periodically through the operational life of the LLBGs to reflect updated information on waste inventory. management practices, facility transition planning, schedule dates, assessments of post-closure performance, and environmental consequences. Out year dates identified in this plan are tentative. A Final Closure Plan will be prepared in the future when the timing and extent of closure-related activities for LLBGs can be established with greater certainty. After current operations at the LLBGs are concluded, this plan proposes transitioning of these facilities to the Environmental Restoration Program. This action will enable the Environmental Restoration Program to design and implement consistent and coordinated final remedial actions for active and inactive LLBGs. Active and inactive burial grounds in the 200 West and 200 East Areas are commingled. This plan describes approaches that will be implemented during Interim Closure, Final Closure, and Institutional Control Periods to prepare LLBGs for surface barriers, and the construction of barriers, as well as the scope of inspection, monitoring and maintenance practices that will be performed during

  17. Exploring sustainable burial practices in South Africa: Potential challenges and opportunities

    CSIR Research Space (South Africa)

    Leuta, T


    Full Text Available be borne in mind that these figures were calculated based on the number of reported burials, but that the significant shortfall between this and assumed deaths implies that there may be as many unaccounted for burials as there are burials being reported... spaces in the metropolitan areas of eThekwini and the City of Cape Town (CSIR, 2010) it was highlighted that if the death rate is higher or fewer people are cremated, demand for land required for burial will increase. Current trends are that e...

  18. Preliminary soilwater conductivity analysis to date clandestine burials of homicide victims. (United States)

    Pringle, Jamie K; Cassella, John P; Jervis, John R


    This study reports on a new geoscientific method to estimate the post-burial interval (PBI) and potential post-mortem interval (PMI) date of homicide victims in clandestine graves by measuring decomposition fluid conductivities. Establishing PBI/PMI dates may be critical for forensic investigators to establish time-lines to link or indeed rule out suspects to a crime. Regular in situ soilwater analysis from a simulated clandestine grave (which contained a domestic buried pig carcass) in a semi-rural environment had significantly elevated conductivity measurements when compared to background values. A temporal rapid increase of the conductivity of burial fluids was observed until one-year post-burial, after this values slowly increased until two years (end of the current study period). Conversion of x-axis from post-burial days to 'accumulated degree days' (ADDs) corrected for both local temperature variations and associated depth of burial and resulted in an improved fit for multiple linear regression analyses. ADD correction also allowed comparison with a previous conductivity grave study on a different site with a different soil type and environment; this showed comparable results with a similar trend observed. A separate simulated discovered burial had a conductivity estimated PBI date that showed 12% error from its actual burial date. Research is also applicable in examining illegal animal burials; time of burial and waste deposition. Further research is required to extend the monitoring period, to use human cadavers and to repeat this with other soil types and depositional environments.

  19. Prediction of Diagenetic Facies using Well Logs: Evidences from Upper Triassic Yanchang Formation Chang 8 Sandstones in Jiyuan Region, Ordos Basin, China

    Directory of Open Access Journals (Sweden)

    Lai Jin


    Full Text Available The eighth member of Upper Triassic Yanchang Formation (Chang 8 is the major oil reservoir unit in Jiyuan oil field, though with the high potential for oil exploration. The Chang 8 sandstones are characterized with low porosity, low permeability and strong microscopic heterogeneities due to the complex deep-burial diagenetic history. Detailed petrological studies by thin section, X-ray diffraction, scanning electron microscopy, core analysis have been used to investigate the lithogology characteristics, diagenesis, diagenetic minerals and their coupling impacts on reservoir property. The results show that Chang 8 sandstones comprise fine to mediumgrained subarkoses, feldspathic litharenites. The pore systems are dominated by remaining primary intergranular pores, secondary dissolution porosity and micropores. Then, five diagenetic facies were divided in Chang 8 sandstones based on the type and degree of diagenesis, diagenetic minerals assemblages and their coupling effects on the reservoir quality. They consist of grain-coating chlorite weak dissolution facies, unstable component dissolution facies, tight compaction facies, clay minerals filling facies and carbonate cementation facies. The well logging response characteristics of various diagenetic facies are summarized on Gamma Ray (GR, Density Logging (DEN, Acoustic (AC, Compensated Neutron Logging (CNL, and True Formation Resistivity (RT by translating diagenetic facies to well log responses, the diagenetic facies were defined by a set of log responses, and porosity, permeability ranges for each diagenetic facies were determined from core analyses. Well log data of Luo 13 and Chi 212 are processed to evaluate the accuracy of the predictive model. The diagenetic facies are predicted on the vertical profile based on the generated model. Predicted distribution of diagenetic facies precisely coincide with the microscopic observations, and diagenetic facies in Chang 8 sandstones are generally

  20. Evolution of oceanic molybdenum and uranium reservoir size around the Ediacaran-Cambrian transition: Evidence from western Zhejiang, South China (United States)

    Xiang, Lei; Schoepfer, Shane D.; Shen, Shu-zhong; Cao, Chang-qun; Zhang, Hua


    The "Cambrian explosion" is one of the most fascinating episodes of diversification in the history of life; however, its relationship to the oxygenation of the oceans and atmosphere around the Ediacaran-Cambrian transition is not fully understood. Marine inventories of redox-sensitive trace elements reflect the relative balance of oxidative weathering on land and deposition in anoxic water masses, and can be used to explore the evolution of oceanic and atmospheric redox conditions. For this study, we conducted a series of geochemical analyses on the upper Lantian, Piyuancun, and Hetang formations in the Chunye-1 well, part of the lower Yangtze Block in western Zhejiang. Iron speciation results indicate that the entire studied interval was deposited under anoxic conditions, with three intervals of persistent euxinia occurring in the uppermost Lantian Fm., the lower Hetang Formation (Fm.), and the upper Hetang Fm. Molybdenum (Mo) and uranium (U) contents and Mo/TOC and U/TOC ratios from the anoxic/euxinic intervals of the Chunye-1 well, combined with published data from the sections in the middle and upper Yangtze Block, suggest that the oceanic Mo reservoir declined consistently from the Ediacaran to Cambrian Stage 3, while the size of the oceanic U reservoir remained relatively constant. Both metals were depleted in the ocean in lower Cambrian Stage 4, before increasing markedly at the end of Stage 4. The lack of an apparent increase in the size of the marine Mo and U reservoir from the upper Ediacaran to Cambrian Stage 3 suggests that oxic water masses did not expand until Cambrian Stage 4. The increase in marine Mo and U availability in the upper Hetang Fm. may have been due to the expansion of oxic water masses in the oceans, associated with oxygenation of the atmosphere during Cambrian Stage 4. This expansion of oxic waters in the global ocean postdates the main phase of Cambrian diversification, suggesting that pervasive oxygenation of the ocean on a large

  1. Traces of the heritage arising from the Macelj sandstone (United States)

    Golež, Mateja


    The landscape of Southeast Slovenia and its stone heritage principally reveal itself through various Miocene sandstones. The most frequently found type on the borderline between Slovenia and Croatia, i.e. east of Rogatec, is the micaceous-quartz Macelj sandstone. This rock ranges in colour from greenish grey to bluish grey and yellowish, depending on the content of glauconite, which colours it green. In its composition, the rock is a heterogeneous mixture of grains of quartz, dolomite, muscovite, microcline, anorthite and glauconite. The average size of grains is 300μm. In cross-section, they are oblong, semi-rounded or round. The mechanical-physical and durability properties of the Macelj sandstone, which have been characterised pursuant to the applicable standards for natural stone, reveal that the rock exhibits poor resistance to active substances from the atmosphere, particularly in the presence of salt. In the surroundings of Rogatec, there are around 45 abandoned quarries of the Macelj sandstone, which are the result of the exploitation of this mineral resource from the 17th century on. The local quarrymen earned their bread until 1957, when the Kambrus quarry industry closed down. From the original use of this mineral resource as construction and decorative material, the useful value of the Macelj sandstone expanded during the development of the metals industry to the manufacture of large and small grindstones for the needs of the domestic and international market. Therefore, traces of quarrying can not only be seen in the disused quarries, but also in the rich architectural heritage of Rogatec and its surroundings, the stone furniture - from portals, window frames, wells, various troughs, pavements to stone walls - and other. The living quarrying heritage slowly passed into oblivion after World War II, although the analysis of the social image of the people residing in Rogatec and its surroundings revealed that there was an average of one stonemason in

  2. The Application of GPR in Florida for Detecting Forensic Burials

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Koppenjan; J. J. Schultz; S. Ono; H. Lee


    A study was performed at the University of Florida to measure ground penetrating radar(GPR) performance for detecting forensic burials. In controlled scenarios, 24 burials were constructed with pig cadavers. Two soils were utilized to represent two of the most common soil orders in Florida: an Entisol and an Ultisol. Graves were monitored on a monthly basis for time periods up to 21 months with grid data acquired with pulsed and swept-frequency GPR systems incorporating several different frequency antennas. A small subset of the graves was excavated to assess decomposition and relate to the GPR images during the test. The grave anomalies in the GPR depth profiles became less distinctive over time due to body decomposition and settling of the disturbed soil (backfill) as it compacted. Soil type was a major factor. Grave anomalies became more difficult to recognize over time for deep targets that were within clay. Forensic targets that were in sandy soil were recognized for the duration of this study. Time elapsed imagery will be presented to elucidate the changes, or lack thereof, of grave anomalies over the duration of this study. Further analysis was performed using Synthetic Aperture Radar (SAR) reconstruction of images in 2-D and 3-D.

  3. Ancient Item Spoilage Ritual Used in Nomadic Burial Rite

    Directory of Open Access Journals (Sweden)

    Beisenov Arman Z.


    Full Text Available The article considers the findings of items in ancient burials which were intentionally spoiled prior to deposition in graves. This tradition was widely spread both in terms of chronology and geography, and therefore cannot be attributed to any individual cultures or regions. The authors present new information on the ritual obtained during an investigation of Borsyk burial mound of the Middle Sarmatian period located in West Kazakhstan. The central grave of barrow 6 contained a heavily damaged bronze cauldron. The grave was looted in antiquity. Individual scattered bones of a human skeleton and minor gold foil adornments from the ceremonial dress of a nobleman were discovered in the grave. The authors suggest that the cauldron was intentionally deformed by the participants of an ancient mortuary and memorial ritual. According to the principal hypothesis concerning the essence of this ritual, spoilage of the items was related to the idea of assign the items with “different” and “transcendent” properties, which resulted from the necessity of burying the owner. Cauldrons played an important role in the life of steppe leaders. The authors assume a sacral nature of the use of cauldrons in the culture of steppe peoples associated with feasts, battles, and sacred hunting. Perhaps, there was a tradition of burying cauldrons together with their owners after spoiling the items in view of the concept of the other world and the role of a heroic leader therein.

  4. Burial increases seed longevity of two Artemisia tridentata (Asteraceae) subspecies (United States)

    Wijayratne, Upekala C.; Pyke, David A.


    Premise of the study: Seed longevity and persistence in soil seed banks may be especially important for population persistence in ecosystems where opportunities for seedling establishment and disturbance are unpredictable. The fire regime, an important driver of population dynamics in sagebrush steppe ecosystems, has been altered by exotic annual grass invasion. Soil seed banks may play an active role in postfire recovery of the foundation shrub Artemisia tridentata, yet conditions under which seeds persist are largely unknown. Methods: We investigated seed longevity of two Artemisia tridentata subspecies in situ by retrieving seed bags that were placed at varying depths over a 2 yr period. We also sampled naturally dispersed seeds in litter and soil immediately after seed dispersal and before flowering in subsequent seasons to estimate seed persistence. Key results: After 24 mo, seeds buried at least 3 cm below the soil surface retained 30–40% viability whereas viability of seeds on the surface and under litter declined to 0 and Artemisia tridentata has the potential to form a short-term soil seed bank that persists longer than has been commonly assumed, and that burial is necessary for seed longevity. Use of seeding techniques that promote burial of some seeds to aid in formation of a soil seed bank may increase restoration potential.

  5. Ecology and evolution of the diaspore "burial syndrome". (United States)

    Humphreys, Aelys M; Antonelli, Alexandre; Pirie, Michael D; Linder, H Peter


    Hygroscopically active awns or "bristles" have long intrigued scientists. Experimental evidence shows that they are important for diaspore burial in the correct orientation, thereby increasing successful seed germination and seedling survival. Despite these ecological advantages, 38 of the 280 species of grasses in Danthonioideae lack awns. We provide the first study of awns in a phylogenetic context and show that although the awnless state has arisen ca. 25 times independently, the ecological disadvantage of not having an awn also applies in an evolutionary context. Only in Tribolium and Schismus have awnless ancestors diversified to form a clade of primarily awnless descendents. Several of the awnless species in these genera are annual and we find a significant correlation between the evolution of awns and the evolution of life history. A suite of other diaspore traits accompany the awned or awnless states. We interpret the awn as being the visible constituent of a compound "burial syndrome," the two ecological extremes of which may explain the correlation between awns and life history and provide an explanation why awnless species in Tribolium and Schismus persist. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  6. Effects of sediment burial on tropical ruderal seagrasses are moderated by clonal integration (United States)

    Ooi, Jillian Lean Sim; Kendrick, Gary A.; Van Niel, Kimberly P.


    Seagrasses are clonal plants that grow submerged in dynamic sedimentary environments where burial is a common occurrence. Clonal organisms may respond to burial in very different ways depending on how strongly integrated they are through horizontal rhizomes, but the effect of clonal integration under conditions of stress such as burial is poorly studied for seagrasses. We test the effect of burial on tropical seagrasses that occur in multispecific meadows by subjecting plants in mixed stands to burial of 0, 2, 4, 8 and 16 cm for 27 days. Treatments were divided into those where rhizomes were severed and those where rhizomes were left intact. We hypothesize that species withstand burial better if clonal integration is maintained (intact rhizomes). Results showed that all species tolerated burial of up to 4 cm without adverse effects but significant reductions in shoot density and biomass become evident at 8 cm of burial. Furthermore, Cymodocea serrulata and Syringodium isoetifolium were strong integrators, i.e. they provide support for buried shoots, whereas Halophila ovalis and Halodule uninervis were weak integrators that did not show evidence of subsidizing buried shoots. Vertical elongation was observed for C. serrulata and H. uninervis as a response to burial only when rhizomes were severed, leading us to speculate on whether species rely on vertical elongation as an escape strategy only in the absence of resource translocation. Our distinction between the responses of treatments with intact rhizomes from those with severed rhizomes may be extended to an interpretation of burial scale (intact rhizomes=broad spatial-scale burial; severed rhizomes=fine spatial-scale burial). We concluded that broad spatial-scale burial exceeding 4 cm leads to rapid loss or reduction of all species. However, fine spatial-scale burial exceeding 4 cm, such as those caused by shrimp mounds (bioturbation), is expected to favor C. serrulata and S. isoetifolium, while H. ovalis and H

  7. Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River Basins, Wyoming. Annual report, October 1, 1994-- September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, T.L.


    This research is to provide improved strategies for enhanced oil recovery from the Tensleep Sandstone oil reservoirs in the Bighorn and Wind River basins, Wyoming. Because of the great range of API gravities of the oils produced from these reservoirs, the proposed study concentrates on understanding the spatial variation and anisotropy of relative permeability within the Tensleep Sandstone. This research will associate those spatial distributions and anisotropies with the depositional subfacies and zones of diagenetic alteration found within the sandstone. The associations of the above with pore geometry will link relative permeability with the dimensions of lithofacies and authigenic mineral facies. Hence, the study is to provide criteria for scaling this parameter on a range of scales, from the laboratory to the basin-wide scale of subfacies distribution. Effects of depositional processes and burial diagenesis will be investigated. Image analysis of pore systems will be done to produce algorithms for estimating relative permeability from petrographic analyses of core and well cuttings. In addition, these studies are being coupled with geochemical modeling and coreflood experiments to investigate the potential for wellbore scaling and formation damage anticipated during EOR, eg., CO{sub 2} flooding. This will provide a regional basis for EOR strategies for the largest potential target reservoir in Wyoming; results will have application to all eolian reservoirs through correlations of relative permeability variation and anisotropy with eolian depositional lithofacies.

  8. Effect Of Hot Water Injection On Sandstone Permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke


    The seasonal imbalance between supply and demand of renewable energy requires temporary storage, which can be achieved by hot water injection in warm aquifers. This requires that the permeability and porosity of the aquifer are not reduced significantly by heating. We present an overview...... of published results regarding the effect of temperature on sandstone permeability. These tests are performed with mineral oil, nitrogen gas, distilled water and solutions of NaCl, KCl, CaCl2 as well as brines that contain a mixture of salts. Thirteen sandstone formations, ranging from quartz arenites...... not account for all the permeability reductions observed. Permeablity reduction occurs both when distilled water is the saturating fluid as well as in tests with NaCl, KCl or CaCl2 solutions, however, this is not the case in tests with mineral oil or nitrogen gas. The formation of a filter cake or influx...

  9. New acid systems for sandstone stimulation. [Oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.J.; Wong, T.C.T.; Mungan, N.


    A new series of prepackaged acid systems have been developed for stimulation of sandstone formations. The original system, containing phosphoric acid and other additives (P.P.A.S.) was specifically formulated to overcome several limitations of existing acid systems. The scope of applications for P.P.A.S. has since been expanded by combining HCl (Hydrochloric acid) or HF (Hydrofluoric acid) with the P.P.A.S. to form hybrid systems that have unique properties. These new systems have been successfully used for stimulating sandstone formations that have been difficult to treat with existing acid systems. The problems associated with currently used acids and their limitations are compared to the P.P.A.S. to illustrate the advantages of these new systems. 10 refs.

  10. Micromechanics of compaction in an analogue reservoir sandstone

    Energy Technology Data Exchange (ETDEWEB)



    Energy production, deformation, and fluid transport in reservoirs are linked closely. Recent field, laboratory, and theoretical studies suggest that, under certain stress conditions, compaction of porous rocks may be accommodated by narrow zones of localized compressive deformation oriented perpendicular to the maximum compressive stress. Triaxial compression experiments were performed on Castlegate, an analogue reservoir sandstone, that included acoustic emission detection and location. Initially, acoustic emissions were focused in horizontal bands that initiated at the sample ends (perpendicular to the maximum compressive stress), but with continued loading progressed axially towards the center. This paper describes microscopy studies that were performed to elucidate the micromechanics of compaction during the experiments. The microscopy revealed that compaction of this weakly-cemented sandstone proceeded in two phases: an initial stage of porosity decrease accomplished by breakage of grain contacts and grain rotation, and a second stage of further reduction accommodated by intense grain breakage and rotation.

  11. Provenance of the lower Triassic bunter sandstone formation

    DEFF Research Database (Denmark)

    Olivarius, Mette; Weibel, Rikke; Friis, Henrik


    Zircon U–Pb geochronometry, heavy mineral analyses and conventional seismic reflection data were used to interpret the provenance of the Lower Triassic Bunter Sandstone Formation. The succession was sampled in five Danish wells in the northern part of the North German Basin. The results show...... in the platform area and marginal basin area, but the complex sand-body architecture makes it difficult to predict the reservoir quality. Continue reading full article...

  12. New Acid Combination for a Successful Sandstone Acidizing (United States)

    Shafiq, M. U.; Mahmud, H. K. B.; Rezaee, R.


    With the development of new enhanced oil recovery techniques, sandstone acidizing has been introduced and played a pivotal role in the petroleum industry. Different acid combinations have been applied, which react with the formation, dissolve the soluble particles; thus increase the production of hydrocarbons. To solve the problems which occurred using current preflush sandstone acidizing technology (hydrochloric acid); a new acid combination has been developed. Core flooding experiments on sandstone core samples with dimensions 1.5 in. × 3 in. were conducted at a flow rate of 2 cm3/min. A series of hydrochloric-acetic acid mixtures with different ratios were tested under 150°F temperature. The core flooding experiments performed are aimed to dissolve carbonate, sodium, potassium and calcium particles from the core samples. These experiments are followed by few important tests which include, porosity-permeability, pH value, Inductively Coupled Plasma (ICP) analysis and Nuclear Magnetic Resonance (NMR measurements). All the results are compared with the results of conventional hydrochloric acid technology. NMR and porosity analysis concluded that the new acid combination is more effective in creating fresh pore spaces and thus increasing the reservoir permeability. It can be seen from the pore distribution before and after the acidizing. Prior applying acid; the large size of pores appears most frequently in the pore distribution while with the applied acid, it was found that the small pore size is most the predominant of the pore distribution. These results are validated using ICP analysis which shows the effective removal of calcium and other positive ions from the core sample. This study concludes that the combination of acetic-hydrochloric acid can be a potential candidate for the preflush stage of sandstone acidizing at high temperature reservoirs.

  13. New data on the Lower Cambrian trilobites of Cortijos de Malagon (Spain

    Directory of Open Access Journals (Sweden)

    Jago, J. B.


    Full Text Available A Small trilobite fauna from the late Lower Cambrian Sanstones from Los Cortijos de Malagon of Southem Spain is described herein. This fauna ineludes the following taxa: Realaspis (? sp.; Kingaspis (? sp.; cf. Latoucheia sp. and Lusatiops afI. ribotanusd, Richter and Richter, 1948.En este trabajo se describe la fauna de trilobites del Cámbrico inferior de las areniscas de los Cortijos de Malagón en el SE español. Comprende Realaspis (? sp., Kingaspis (? sp.; cf. Latoucheia sp. y Lusatiops afI. ribotanus. Richter y Richter, 1948.


    Directory of Open Access Journals (Sweden)



    Full Text Available Outcrops of Cambrian sediments of the uppermost Miqrat Formation, the Al Bashair Formation and the basal Barik Formation were sampled for conodont and palynomorph studies. The units are part of the Palaeozoic Haima Supergroup, exposed in the Huqf-Haushi area in central eastern Oman, Arabian Peninsula. Palynomorphs were absent but conodont samples yielded a small conodont fauna. The presence of Muellerodus? erectus allows the recognition of the Muellerodus? erectus Zone established for North China (late Paibian – early Jiangshanian, in accordance with previous reports on the trilobite fauna from the same interval.

  15. 32 CFR 553.17 - Persons ineligible for burial in an Army national cemetery. (United States)


    ... separation from one of the Armed Forces was under other-than-honorable conditions is not eligible for burial... died in such a hospital. (c) A person who has volunteered for service with the Armed Forces but has not... for burial in Arlington National Cemetery unless the Service-connected family member has been or will...

  16. About One of Burials of Novotitorovka Culture From the Territory of Kuban

    Directory of Open Access Journals (Sweden)

    Mariya A. Balabanova


    Full Text Available The article is devoted to the burial complex and the skull of the Novotitorovka culture from burial no. 35 of the Ovalny burial mound, Kalininsky district of the Krasnodar region. The burial itself was non-inventory, but it was synchronous with burial no. 26. Both burials were excavated from the level of the ancient surface and covered by the same barrow. The bones from the studied burial belonged to a young man, who died at the age of 20-25. His craniological type is characterized by meso-dolichocrania, ellipsoidal vertical norm, the average width of forehead, wide and low face, orthognathy-like in a vertical plane and slightly profiled at the level of low eye sockets. The face is also characterized by narrow and sharply protruding nasal bones. The article also deals with the possible relationship between the tribes of the Novotitorovka culture and the Azov-Black Sea sites of Catacomb culture. This conclusion is based on the results of intergroup comparison by the method of canonical analysis. The studied skull of the Novotitorovka culture has a morphological complex that characterizes the groups of burials of the Catacomb culture localized on the terraces of the Ingul river and on the terraces of the Don river left bank. This conclusion calls into question the archaeologists’ hypothesis on the connection of the the Novotitorovka culture with the tribes of the Novosvobodnenskaya culture and the Maykop culture.

  17. Introduction: Life Space and Burial Space in the Post-Apartheid City ...

    African Journals Online (AJOL)

    Landscapes of the dead are always, simultaneously, landscapes of the living. It is this coterminousness of life and death that gives the burial site its salience and emotional power. Different societies, at different times, renegotiate the relationship between what anthropologists call 'life space\\' and 'burial space\\', depending on ...

  18. Determination of burial dose in incompletely bleached fluvial samples using single grains of quartz

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, Lars


    We determine the burial dose in three known-age incompletely bleached fluvial samples using single grains of quartz. Estimation of burial dose in incompletely bleached samples requires that the characteristics of the well-bleached part of the distribution are known in order to distinguish between...

  19. Cleanup Verification Package for the 118-C-1, 105-C Solid Waste Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    M. J. Appel and J. M. Capron


    This cleanup verification package documents completion of remedial action for the 118-C-1, 105-C Solid Waste Burial Ground. This waste site was the primary burial ground for general wastes from the operation of the 105-C Reactor and received process tubes, aluminum fuel spacers, control rods, reactor hardware, spent nuclear fuel and soft wastes.

  20. Intraspecific variation of a desert shrub species in phenotypic plasticity in response to sand burial

    NARCIS (Netherlands)

    Xu, L.; Huber, H.; During, H.J.; Dong, M.; Anten, N.P.R.


    Shoot elongation is one of the main plastic responses of plants to burial, a ubiquitous stress factor in dry ecosystems. Yet, intraspecific variation in this response to burial and the extent to which this variation is functionally coordinated with variation in other trait responses are largely

  1. Necropolis on Bor lake: New reports on Bronze age burial

    Directory of Open Access Journals (Sweden)

    Kapuran Aleksandar


    Full Text Available This article deals with the social and anthropological aspects of burial rituals during the Middle Bronze Age in Timočka Krajina. Decades of systematic research of necropolises and reconnaissance in the basin of the Crni Timok proved an increase in number of sites around ore - rich areas of the east Kučaj mountains as well as around Romuliana site and the fertile valleys of Džanovo polje (Map. 1. The quantitative increase in settlements was reflected by the emergence of large necropolises, only three of which have been systematically explored; those in Trnjani, Magura and Bor Lake (Fig. 1; Plan 1. Analysis of geographical features of many settlements and their position in relation to natural resources helped define two communities, one of which carried out mining and metallurgical activities, while the other group engaged in the production of food. Both groups lived in the immediate vicinity and mutual dependence, functioning within a developed market for copper production. During the exploration of the necropolis near Bor Lake in 1997, the remains of burnt skeletons were collected from burial structures 2/97 and 13/97 (Fig. 2; Plans 2 and 3. Anthropological analysis of the cremated remains of the deceased showed that high temperatures were used during the cremation process, which we assume could have only been achieved in metallurgical furnaces. This is confirmed by the fact that the skeletal fragments contain traces of melted metal, as well as finds of bronze slag inside urns and grave structures in the necropolis in Trnjani (Figs. 3 and 4; Tables 1-4. Burial ritual of this kind was not proved by systematic archaeological research of necropolises in the basin of Crni Timok, although anthropological data collected from necropolises linked to metallurgical settlements may indicate some guidelines in the ritual cremation of prominent members of these communities. [Projekat Ministarstva nauke Republike Srbije, br. 177020: Arheologija Srbije

  2. Cambrian Evolutionary Radiation: Context, correlation, and chronostratigraphy—Overcoming deficiencies of the first appearance datum (FAD) concept (United States)

    Landing, Ed; Geyer, Gerd; Brasier, Martin D.; Bowring, Samuel A.


    Use of the first appearance datum (FAD) of a fossil to define a global chronostratigraphic unit's base can lead to intractable correlation and stability problems. FADs are diachronous—they reflect species' evolutionary history, dispersal, biofacies, preservation, collection, and taxonomy. The Cambrian Evolutionary Radiation is characterised by diachronous FADs, biofacies controls, and provincialism of taxa and ecological communities that confound a stable Lower Cambrian chronostratigraphy. Cambrian series and stage definitions require greater attention to assemblage zone successions and non-biostratigraphic, particularly carbon isotope, correlation techniques such as those that define the Ediacaran System base. A redefined, basal Cambrian Trichophycus pedum Assemblage Zone lies above the highest Ediacaran-type biotas (vendobionts, putative metazoans, and calcareous problematica such as Cloudina) and the basal Asteridium tornatum-Comasphaeridium velvetum Zone (acritarchs). This definition and the likely close correspondence of evolutionary origin and local FAD of T. pedum preserves the Fortune Head, Newfoundland, GSSP of the Cambrian base and allows the presence of sub-Cambrian, branched ichnofossils. The sub-Tommotian-equivalent base of Stage 2 (a suggested "Laolinian Stage") should be defined by the I'/L4/ZHUCE δ13C positive peak, bracketed by the lower ranges of Watsonella crosbyi and Aldanella attleborensis (molluscs) and the Skiagia ornata-Fimbrioglomerella membranacea Zone (acritarchs). The W. crosbyi and A. attleborensis FADs cannot define a Stage 2 base as they are diachronous even in the Newfoundland "type" W. crosbyi Zone. The Series 2 base cannot be based on a species' FAD owing to the provincialism of skeletalised metazoans in the Terreneuvian-Series 2 boundary interval and global heterochrony of the oldest trilobites. A Series 2 and Stage 3 (a suggested "Lenaldanian Series" and "Zhurinskyan Stage," new) GSSP base is proposed at the Siberian lower

  3. Evidence supporting an intentional Neandertal burial at La Chapelle-aux-Saints. (United States)

    Rendu, William; Beauval, Cédric; Crevecoeur, Isabelle; Bayle, Priscilla; Balzeau, Antoine; Bismuth, Thierry; Bourguignon, Laurence; Delfour, Géraldine; Faivre, Jean-Philippe; Lacrampe-Cuyaubère, François; Tavormina, Carlotta; Todisco, Dominique; Turq, Alain; Maureille, Bruno


    The bouffia Bonneval at La Chapelle-aux-Saints is well known for the discovery of the first secure Neandertal burial in the early 20th century. However, the intentionality of the burial remains an issue of some debate. Here, we present the results of a 12-y fieldwork project, along with a taphonomic analysis of the human remains, designed to assess the funerary context of the La Chapelle-aux-Saints Neandertal. We have established the anthropogenic nature of the burial pit and underlined the taphonomic evidence of a rapid burial of the body. These multiple lines of evidence support the hypothesis of an intentional burial. Finally, the discovery of skeletal elements belonging to the original La Chapelle aux Saints 1 individual, two additional young individuals, and a second adult in the bouffia Bonneval highlights a more complex site-formation history than previously proposed.

  4. On the water saturation calculation in hydrocarbon sandstone reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Stalheim, Stein Ottar


    The main goal of this work was to identify the most important uncertainty sources in water saturation calculation and examine the possibility for developing new S{sub w} - equations or possibility to develop methods to remove weaknesses and uncertainties in existing S{sub w} - equations. Due to the need for industrial applicability of the equations we aimed for results with the following properties: The accuracy in S{sub w} should increase compared with existing S{sub w} - equations. The equations should be simple to use in petrophysical evaluations. The equations should be based on conventional logs and use as few as possible input parameters. The equations should be numerical stable. This thesis includes an uncertainty and sensitivity analysis of the most common S{sub w} equations. The results are addressed in chapter 3 and were intended to find the most important uncertainty sources in water saturation calculation. To increase the knowledge of the relationship between R{sub t} and S{sub w} in hydrocarbon sandstone reservoirs and to understand how the pore geometry affects the conductivity (n and m) of the rock a theoretical study was done. It was also an aim to examine the possibility for developing new S{sub w} - equations (or investigation an effective medium model) valid inhydrocarbon sandstone reservoirs. The results are presented in paper 1. A new equation for water saturation calculation in clean sandstone oil reservoirs is addressed in paper 2. A recommendation for best practice of water saturation calculation in non water wet formation is addressed in paper 3. Finally a new equation for water saturation calculation in thinly interbedded sandstone/mudstone reservoirs is presented in paper 4. The papers are titled: 1) Is the saturation exponent n a constant. 2) A New Model for Calculating Water Saturation In 3) Influence of wettability on water saturation modeling. 4) Water Saturation Calculations in Thinly Interbedded Sandstone/mudstone Reservoirs. A

  5. Experimental deformation in sandstone, carbonates and quartz aggregate

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Cecilia See Nga [Stony Brook Univ., NY (United States)


    The first part of my thesis is mainly focused on the effect of grain size distribution on compaction localization in porous sandstone. To identify the microstructural parameters that influence compaction band formation, I conducted a systematic study of mechanical deformation, failure mode and microstructural evolution in Bleurswiller and Boise sandstones, of similar porosity (~25%) and mineralogy but different sorting. Discrete compaction bands were observed to develop over a wide range of pressure in the Bleurswiller sandstone that has a relatively uniform grain size distribution. In contrast, compaction localization was not observed in the poorly sorted Boise sandstone. My results demonstrate that grain size distribution exerts important influence on compaction band development, in agreement with recently published data from Valley of Fire and Buckskin Gulch, as well as numerical studies. The second part aimed to improve current knowledge on inelastic behavior, failure mode and brittle-ductile transition in another sedimentary rock, porous carbonates. A micritic Tavel (porosity of ~13%) and an allochemical Indiana (~18%) limestones were deformed under compaction in wet and dry conditions. At lower confining pressures, shear localization occurred in brittle faulting regime. Through transitional regime, the deformation switched to cataclastic flow regime at higher confining pressure. Specifically in the cataclastic regime, the (dry and wet) Tavel and dry Indiana failed by distributed cataclastic flow, while in contrast, wet Indiana failed as compaction localization. My results demonstrate that different failure modes and mechanical behaviors under different deformation regimes and water saturation are fundamental prior to any geophysical application in porous carbonates. The third part aimed to focus on investigating compaction on quartz aggregate starting at low (MPa) using X-ray diffraction. We report the diffraction peak evolution of quartz with increasing

  6. Effects of urban stream burial on nitrogen uptake and ecosystem metabolism: implications for watershed nitrogen and carbon fluxes (United States)

    Urbanization has resulted in extensive burial and channelization of headwater streams, yet little is known about impacts on stream ecosystem functions critical for reducing downstream nitrogen pollution. To characterize the biogeochemical impact of stream burial, we measured NO3...

  7. 40Ar/39Ar dating of exceptional concentration of metals by weathering of Precambrian rocks at the Precambrian–Cambrian boundary

    DEFF Research Database (Denmark)

    Parnell, John; Mark, Darren F.; Frei, Robert


    The sub-Cambrian surface, including diverse metalliferous deposits, shows evidence of intense weathering of Precambrian rocks to form supergene-enriched ores and metalliferous placers, followed by widespread peneplanation. Much of the metal would have been flushed to the Cambrian ocean during pen...... with mobilization on land of redox sensitive metals by oxidative terrestrial weathering. This unprecedented flushing of metals from the weathered Precambrian surface would have contributed to the chemistry of the earliest Cambrian ocean at a time of marked faunal evolution.......The sub-Cambrian surface, including diverse metalliferous deposits, shows evidence of intense weathering of Precambrian rocks to form supergene-enriched ores and metalliferous placers, followed by widespread peneplanation. Much of the metal would have been flushed to the Cambrian ocean during...

  8. Investigation and simulation on fate and transport of leachate from a livestock mortality burial site (United States)

    Lim, J.-W.; Lee, S.; Kaown, D.; Lee, K.-K.


    Leachate released from livestock mortality burial during decomposition of carcasses can be a threat to groundwater quality. Monitoring study of groundwater quality in the vicinity of livestock burial reported that a caution is needed to prevent contamination of both groundwater and soil, especially in case of mortality burial (Glanville, 2000; Ritter and Chirnside, 1995). The average concentration of ammonium-N and chloride is reported to be 12,600 mg/l and 2,600 mg/l respectively, which is 2-4 times higher than leachate from earthen manure storages and landfills (Pratt, 2009). To assess the potential threat of burial leachate to groundwater quality, simulation of leachate transport is performed based on a hydrogeologic model of an actual mortality burial site. At the burial site of this study located at a hill slope, two mortality pits have been constructed along the slope to bury swine during the outbreak of nationwide foot and mouth disease(FMD) in 2011. Though the pits were partially lined with impermeable material, potential threat of leachate leakage is still in concern. Electrical resistivity survey has been performed several times at the burial site and abnormal resistivity zones have been detected which are supposed as leachate leakage from the burial. Subsurface model including unsaturated zone is built since the leakage is supposed to occur mainly in lateral of the burial pits which is in unsaturated zone. When examining leachate transport, main focus is given to a nitrogenous compound and colloidal character of FMD virus. Nitrifying of denitrifying characters of nitrogenous compound and transport of colloidal particles are affected mainly by soil water content in unsaturated zone. Thus, the fate and transport of burial leachate affected by seasonal variation in recharge pattern is investigated.

  9. Determination of post-burial interval using entomology: A review. (United States)

    Singh, Rajinder; Sharma, Sahil; Sharma, Arun


    Insects and other arthropods are used in different matters pertinent to the criminal justice system as they play very important role in the decomposition of cadavers. They are used as evidence in a criminal investigation to determine post mortem interval (PMI). Various researches and review articles are available on forensic entomology to determine PMI in the terrestrial environment but very less work has been reported in context to buried bodies. Burring the carcass, is one of the methods used by criminals to conceal the crime. So, to drive the attention of researchers toward this growing field and to help various investigating agencies, the present paper reviews the studies done on determination of post-burial interval (PBI), its importance and future prospective. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  10. Burial stress and elastic strain of carbonate rocks

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke


    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...

  11. Aboveground burial for managing catastrophic losses of livestock

    Directory of Open Access Journals (Sweden)

    Gary Alan Flory


    Full Text Available Background and Aim: Environmental impacts from carcass management are a significant concern globally. Despite a history of costly, ineffective, and environmentally damaging carcass disposal efforts, large animal carcass disposal methods have advanced little in the past decade. An outbreak today will likely be managed with the same carcass disposal techniques used in the previous decades and will likely result in the same economic, health, and environmental impacts. This article overviews the results of one field test that was completed in Virginia (United States using the aboveground burial (AGB technique and the disposal of 111 foot-and-mouth disease (FMD infected sheep in Tunisia using a similar methodology. Materials and Methods: Researchers in the United States conducted a field test to assess the environmental impact and effectiveness of AGB in decomposing livestock carcasses. The system design included a shallow trench excavated into native soil and a carbonaceous base placed on the bottom of the trenches followed by a single layer of animal carcasses. Excavated soils were subsequently placed on top of the animals, and a vegetative layer was established. A similar methodology was used in Tunisia to manage sheep infected with FMDs, Peste des Petits Ruminants virus, and Bluetongue Virus. Results: The results of the field test in the United States demonstrated a significant carcass degradation during the 1-year period of the project, and the migration of nutrients below the carcasses appears to be limited thereby minimizing the threat of groundwater contamination. The methodology proved practical for the disposal of infected sheep carcasses in Tunisia. Conclusions: Based on the analysis conducted to date, AGB appears to offer many benefits over traditional burial for catastrophic mortality management. Ongoing research will help to identify limitations of the method and determine where its application during large disease outbreaks or natural

  12. Brachiopods hitching a ride: an early case of commensalism in the middle Cambrian Burgess Shale (United States)

    Topper, Timothy P.; Holmer, Lars E.; Caron, Jean-Bernard


    Ecological interactions, including symbiotic associations such as mutualism, parasitism and commensalism are crucial factors in generating evolutionary novelties and strategies. Direct examples of species interactions in the fossil record generally involve organisms attached to sessile organisms in an epibiont or macroboring relationship. Here we provide support for an intimate ecological association between a calcareous brachiopod (Nisusia) and the stem group mollusc Wiwaxia from the Burgess Shale. Brachiopod specimens are fixed to Wiwaxia scleritomes, the latter showing no signs of decay and disarticulation, suggesting a live association. We interpret this association as the oldest unambiguous example of a facultative ectosymbiosis between a sessile organism and a mobile benthic animal in the fossil record. The potential evolutionary advantage of this association is discussed, brachiopods benefiting from ease of attachment, increased food supply, avoidance of turbid benthic conditions, biofoul and possible protection from predators, suggesting commensalism (benefiting the symbiont with no impact for the host). While Cambrian brachiopods are relatively common epibionts, in particular on sponges, the association of Nisusia with the motile Wiwaxia is rare for a brachiopod species, fossil or living, and suggests that symbiotic associations were already well established and diversified by the ``middle'' (Series 3, Stage 5) Cambrian.

  13. Geochemistry of Sulfur and Sulfur Compounds of the Cambrian Kuonamka Complex (Eastern Siberian Platform

    Directory of Open Access Journals (Sweden)

    T.M. Parfenova


    Full Text Available New results of research of sulfur from rocks and organic matter (OM for the Kuonamka complex of the Lower and Middle Cambrian in the eastern Siberian platform have been demonstrated. It has been shown that in the rocks enriched in organic matter the amount of organic carbon controls not only the total content of sulfur and sulfide sulfur, but also the content of sulphate sulfur. It has been revealed that the sulfur content in bitumen extracts of Cambrian black shales in the northeastern Siberian platform decreases with increasing carbon and hydrogen. It was hypothesized that during diagenesis the introduction of sulfur in the OM structure led to dehydrogenation and decarboxylation. The intensity of these processes is associated neither with the mineral composition of the sediment nor with its enrichment in OM. The paper discusses the structure and patterns of distribution of OM sulfur compounds in the rocks of the Kuonamka complex in the sections of the northern and southeastern Siberian platform.

  14. The proterozoic and earliest cambrian trace fossil record; patterns, problems and perspectives. (United States)

    Jensen, Sören


    The increase in trace fossil diversity across the Neoproterozoic-Cambrian boundary often is presented in terms of tabulations of ichnogenera. However, a clearer picture of the increase in diversity and complexity can be reached by combining trace fossils into broad groups defined both on morphology and interpretation. This also focuses attention on looking for similarites between Neoproterozoic and Cambrian trace fossils. Siliciclastic sediments of the Neoproterozoic preserve elongate tubular organisms and structures of probable algal origin, many of which are very similar to trace fossils. Such enigmatic structures include Palaeopascichnus and Yelovichnus, previously thought to be trace fossils in the form of tight meanders.A preliminary two or tripartite terminal Neoproterozoic trace fossil zonation can be be recognized. Possibly the earliest trace fossils are short unbranched forms, probably younger than about 560 Ma. Typical Neoproterozoic trace fossils are unbranched and essentially horizontal forms found associated with diverse assemblages of Ediacaran organisms. In sections younger than about 550 Ma a modest increase in trace fossil diversity occurs, including the appearance of rare three-dimensional burrow systems (treptichnids), and traces with a three-lobed lower surfaces.

  15. Calcified microbes in Neoproterozoic carbonates: implications for our understanding of the Proterozoic/Cambrian transition (United States)

    Knoll, A. H.; Fairchild, I. J.; Swett, K.


    Tidal flat and lagoonal dolostones of the Neoproterozoic Draken Formation, Spitsbergen, exhibit excellent preservation of carbonate fabrics, including heavily calcified microfossils. The crust-forming cyanobacterium Polybessurus is preserved locally by carbonate precipitated on and within sheaths in mildly evaporitic upper intertidal to supratidal environments. In contrast, calcified filaments in columnar stromatolites reflect subtidal precipitation. Filament molds in dolomicrites independently document extremely early lithification. The presence of heavily calcified cyanobacteria in Draken and other Proterozoic carbonates constrains potential explanations for the widespread appearance of calcified microorganisms near the Proterozoic-Cambrian boundary. We propose that the rarity of Proterozoic examples principally reflects the abundance and wide distribution of carbonate crystals precipitated on the sea floor or in the water column. Cyanobacterial sheaths would have competed effectively as sites for carbonate nucleation and growth only where calcitic and/or aragonitic nuclei were absent. In this view, the Proterozoic-Cambrian expansion of calcified microfossils primarily reflects the emergence of skeletons as principal agents of carbonate deposition.

  16. Early Cambrian wave-formed shoreline deposits: the Hardeberga Formation, Bornholm, Denmark (United States)

    Clemmensen, Lars B.; Glad, Aslaug C.; Pedersen, Gunver K.


    During the early Cambrian, the Danish island Bornholm was situated on the northern edge of the continent Baltica with palaeolatitudes of about 35°S. An early Cambrian (Terreneuvian) transgression inundated large areas of Baltica including Bornholm creating shallow marine and coastline environments. During this period, wave-formed shoreline sediments (the Vik Member, Hardeberga Formation) were deposited on Bornholm and are presently exposed at Strøby quarry. The sediments consist of fine- and medium-grained quartz-cemented arenites in association with a few silt-rich mudstones. The presence of well-preserved subaqueous dunes and wave ripples indicates deposition in a wave-dominated upper shoreface (littoral zone) environment, and the presence of interference ripples indicates that the littoral zone environment experienced water level fluctuations due to tides and/or changing meteorological conditions. Discoidal structures (medusoids) are present in the quarry, but due to the relative poor preservation of their fine-scale structures it is difficult to determine if the discoids represent true medusae imprints or inorganic structures. The preservation of the shallow-water bedforms as well as the possible medusae imprints is related to either the formation of thin mud layers, formed during a period of calm water when winds blew offshore for a longer period, or to the growth of bacterial mats. The orientation of the wave-formed bedforms indicates a local palaeoshoreline trending NE-SW and facing a large ocean to the north.

  17. Biofacies and faunal dynamics through the Sirius Passet Lagerstätte (lower Cambrian) (United States)

    Harper, D. A. T.; Hammarlund, E.; Hansen, J. W.; Nielsen, A. T.; Rasmussen, J. A.; Smith, M. P.; Stein, M.; Vinther, J.


    Sirius Passet is one of the three key Cambrian Lagerstätte located in Nansen Land on the northern edge of Greenland. Field counts and identifications of thousands of in situ fossils through almost 13 m of exposed strata within the Transitional Buen Formation (lower Cambrian) at the classic locality southwest of the Sirius Pass, have precisely delimited the context and extent of the Lagerstätte horizons and charted in outline faunal dynamics through the section. To date some 45 species, including about ten new taxa have been related to substrate type, geochemical proxies and the presence of microbial mats and trace fossils. Although the succession is characterized numerically by the abundant trilobite Buenellus and the bivalved Isoxys together with a variety of sponges, multivariate analysis of abundance data, displayed as spindle diagrams, through the middle part of the succession maps out a range of biofacies characterized by varying proportions of annelids, arthropods and lobopods. There is a marked correlation between the occurrence of large soft-bodied arthropods, microbial mats together with sub and under-mat miners. These analyses and observations together confirm the deep-water setting of the Sirius Passet faunas, predominantly composed of near autochthonous faunas with some allochthonous elements, transgressing an older carbonate platform.

  18. 77 FR 58591 - Report on Waste Burial Charges: Changes in Decommissioning Waste Disposal Costs at Low-Level... (United States)


    ... COMMISSION Report on Waste Burial Charges: Changes in Decommissioning Waste Disposal Costs at Low-Level Waste... document entitled: NUREG-1307 Revision 15, ``Report on Waste Burial Charges: Changes in Decommissioning Waste Disposal Costs at Low-Level Waste Burial Facilities.'' DATES: Please submit comments by October 22...

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

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, David; Ellett, Kevin; Leetaru, Hannes


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

  20. "The Ruins": Large cold seep sandstone chimneys in the upper Miocene Santa Margarita Sandstone, Scotts Valley, CA (United States)

    Schwartz, H.; Bazan, C.; Perry, F.; Garrison, R. E.


    In 1856 a peculiar letter in a San Francisco newspaper reported the discovery of an ancient ruin on a sandy hillside in Scotts Valley, CA (Santa Cruz County). The purported "great and magnificent structure" consisted of 50 sandstone columns, some of which were said to be capped by a dome. Exploration of the site by speculators and treasure hunters in the 1850's produced no artifacts or evidence of human activity and regrettably resulted in removal or destruction of most of the original columns. Despite its depletion, and subsequent assessment as a wholly geological phenomenon, the locality is still known locally as "The Ruins". In order to evaluate the origin of the distinctive cementation at the Ruins we mapped its remaining features and collected samples for petrographic, XRD and stable isotope analysis. The site, presently located on private property, consists of at least 12 columns and numerous flattened, discontinuous slabs of well indurated sandstone exposed over ~160 square meters. Stratigraphically it is in the uppermost part of the upper Miocene Santa Margarita Sandstone, 7-15 m below its contact with the overlying Santa Cruz Mudstone. The columns range from 0.5-2 m in diameter and the tallest rises 1.5 m above the surface. All of the columns are distinctly chimney-like, with circular cross sections and hollow central cavities that in some cases are partially filled with separately cemented rings. They describe a SW-NE linear trend on the south side of a hill. A horizon of sandstone slabs, 0.2-1.7 m in length, stratigraphically overlies the chimneys at the top of the hill. Both chimneys and slabs consist of coarse-grained, moderately-sorted sandstone cemented by sparry low-Mg calcite. Most samples also contain abundant remains of the echinoid Astrodapsis spatiosus. δ18O values range from -5.15‰ (chimney) to -2.32‰ (slab); δ13C values range from -19.89‰ (chimney) to -1.95‰ (slab). Stable isotope values seem tied to location rather than contrasting

  1. Characterizing flow pathways in a sandstone aquifer at multiple depths (United States)

    Medici, Giacomo; West, Jared; Mountney, Nigel


    Sandstone aquifers are commonly assumed to represent porous media characterized by a permeable matrix. However, such aquifers may be heavily fractured where 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. This presentation reports well-test results and outcrop-scale studies that reveal how strongly lithified siliciclastic rocks may be entirely dominated by fracture flow at shallow depths (≤ 150 m), similar to limestone and crystalline aquifers. The Triassic St Bees Sandstone Formation of the UK East Irish Sea Basin represents an optimum succession for study of the influence of both sedimentary and tectonic aquifer heterogeneities in a strongly lithified sandstone aquifer-type. This sedimentary succession of fluvial origin accumulated in rapidly subsiding basins, which typically favour preservation of complete depositional cycles, including fine-grained mudstone and silty sandstone layers of floodplain origin interbedded with sandstone-dominated fluvial channel deposits. Vertical joints in the St Bees Sandstone Formation form a pervasive stratabound system whereby joints terminate at bedding-parallel discontinuities. Additionally, normal faults are present through the succession and record development of open-fractures in their damage zones. Here, the shallow aquifer (depth ≤150 m BGL) was characterized in outcrop and well tests. 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 typically represent ˜ 50% of well transmissivity. The remaining flow component is dominated by bed-parallel fractures. However, such sub-horizontal fractures become the

  2. Resurrection imageries: A study of the motives for extravagant burial rituals in ancient Egypt

    Directory of Open Access Journals (Sweden)

    Jock M. Agai


    Full Text Available Unlike in the New Testament whereby faith in Christ can resurrect the dead, the ancient Egyptians believed that the bereaved created the resurrection of their deceased through burial rituals and by encouraging the living to serve their kings. They thought that faith alone in god or the gods was not enough to resurrect the dead, thus they seemingly superimposed resurrection alongside burials. Using the various forms of Egyptian burial rituals and evaluated from the perspective of the Christian concept of resurrection, this researcher attempts to search for the motives behind specific Egyptian burial rituals. The researcher proposes that the activities of the bereaved or of the living over the dead were paramount in resurrecting the dead in ancient Egypt. The purpose of this research is, firstly, to explain how the Egyptian burial rituals influenced their thoughts on resurrection and, secondly, to show that the Egyptian god(s might have depended on the living to raise the dead.Intradisciplinary and/or interdisciplinary implications: The ancient Egyptians lived their lives mainly to satisfy the interests of the dead, hence their extensive burial rituals. Whilst they believed in the power of the gods to raise the dead, there seemed to be another motive behind their burial practices which suggested that the living may have had more power to raise the dead. The power was realised in the activities of the living in the form of burials, tomb designs, mummification, food offering, and in remembering the dead. This research explains that these burial activities were relevant in resurrecting the dead without which the gods alone were not able to do that.

  3. Isochron-burial dating of glacially-driven sediments: first results from the Alps (United States)

    Akçar, Naki; Ivy-Ochs, Susan; Alfimov, Vasily; Claude, Anne; Reber, Regina; Christl, Marcus; Vockenhuber, Christof; Schlunegger, Fritz; Dehnert, Andreas; Rahn, Meinert; Schlüchter, Christian


    The recently introduced method of isochron-burial dating, employs the fact that the samples from a well-defined single bed in a deposit would have the same post-burial but different pre-burial histories. The analysis of cosmogenic 10Be and 26Al in such samples enables the modeling of the post-burial component and the determination of the 26Al/10Be at the time of burial. The isochron-burial age can then be calculated from the initial and the measured ratios. In this study, we focus on the isochron-burial dating of the oldest Quaternary deposits of the Alpine Foreland. These are called Swiss Deckenschotter (cover gravels) as they build mesa-type hill tops on the Mesozoic or Cenozoic bedrock of the Swiss Alpine forelands. Deckenschotter consists of glaciofluvial gravel layers intercalated with glacial and/or overbank deposits. Although previously morphostratigraphically correlated with Günz and Mindel glaciations of Penck and Brückner, the Swiss Deckenschotter is likely much older, and their chronostratigraphy is not well constrained. In order to reconstruct the chronology of these deposits, we collected more than 30 clasts of different lithology, shape and size from a single stratigraphic horizon in an abandoned gravel pit in Siglistorf (canton Zurich). We processed 19 clasts for cosmogenic 10Be and 26Al. Four samples did not yield successful 26Al measurements and two were unsuccessful for 10Be. Most of the samples have low nuclide concentrations, i.e. <20000 10Be at/g and <150000 26Al at/g. Finally, using the 26Al/10Be ratio of the samples we calculated an isochron-burial age of around 1.5 Ma. Our results from this study indicate that glaciofluvial sediments can well be time-calibrated with isochron-burial dating despite the low cosmogenic nuclide concentrations.

  4. Effect of Various Silica Nanofluids: Reduction of Fines Migrations and Surface Modification of Berea Sandstone


    Abhishek, Rockey; Hamouda, Aly Anis


    Abstract: This work is aimed at addressing surface modification of berea sandstone by silica nanofluids (NFs). Three types of nanofluids were used: silica/deionized water (DIW), silica in DIW with a stabilizer fluid (3-Mercaptopropyl Trimethoxysilane) and sulfonate-functionalized silica in DIW. Core flood studies showed that application of silica nanoparticles (NPs) improved water injectivity in sandstone. The change in the measured zeta potential indicated surface modification of sandstone b...

  5. The Stratigraphy of the Cambrian Lancara Formation between the Luna River and the Esla River in the Cantabrian Mountains, Spain

    NARCIS (Netherlands)

    Meer Mohr, van der C.G.


    The Lancara Formation is a unit of carbonate sediments of Lower to Middle Cambrian age in the Cantabrian Mountains of northern Spain. The formation is divisible into a Dolomite Member, a Limestone Member and a Griotte Member. The Dolomite Member and the Limestone Member consist mainly of very

  6. Conodont biostratigraphy of the Upper Cambrian and Lower Ordovician of north-western Öland, south-eastern Sweden

    NARCIS (Netherlands)

    Wamel, W.A. van


    This paper forms part of the author's thesis "Lithostratigraphy, environmental interpretation and conodont biostratigraphy of the Upper Cambrian and Lower Ordovician of north-western bland, south-eastern Sweden". The purpose of this investigation was to unravel the lithogenesis and the history

  7. The paleomagnetism of the salt pseudomorph beds of middle cambrian age from the salt range, West Pakistan

    NARCIS (Netherlands)

    Wensink, H.


    Oriented cores for a paleomagnetic investigation were collected from ten sites in the sedimentary redbeds of the Salt Pseudomorph Beds of Middle Cambrian age m the Salt Range near Khcwra. All samples were subjected to progressive, thermal demagnetization procedures which revealed the

  8. Mineralogy and uranium leaching of ores from Triassic Peribaltic sandstones. (United States)

    Gajda, Dorota; Kiegiel, Katarzyna; Zakrzewska-Koltuniewicz, Grazyna; Chajduk, Ewelina; Bartosiewicz, Iwona; Wolkowicz, Stanislaw

    The recovery of uranium and other valuable metals from Polish Peribaltic sandstones were examined. The solid-liquid extraction is the first stage of the technology of uranium production and it is crucial for the next stages of processing. In the laboratory experiments uranium was leached with efficiencies 71-100 % by acidic lixiviants. Satisfactory results were obtained for the alkaline leaching process. Almost 100 % of uranium was leached with alkaline carbonate solution. In post leaching solutions only uranium and small amounts of vanadium were present.

  9. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.


    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  10. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground. Appendices

    Energy Technology Data Exchange (ETDEWEB)



    Safety and cost information are developed for the conceptual decommissioning of commercial low-level waste (LLW) burial grounds. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are used as reference facilities for the study. The two burial grounds are assumed to have the same site capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology. and hydrology of the two sites are chosen to be typical of real western and eastern sites. Volume 2 (Appendices) contains the detailed analyses and data needed to support the results given in Volume 1.

  11. Storm influence on the burial of objects in a shallow sandy shelf environment


    Papili, S.; T. Wever; Dupont, Y.; Van Lancker, V.


    For rapid assessments of occurrences of sea mines or objects, and probability modelling of object burial mechanisms, knowledge is needed on sediment processes under a variety of hydro meteorological conditions. One approach is to use test mines that record burial mechanisms over longer time periods.A Burial Recording Mine (BRM) was deployed in the Belgian part of the North Sea, in water depths of 7 to 12 m. The area is predominantly sandy, with a continuous spectrum of small- to medium and la...

  12. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground. Main Report

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, E. S.; Holter, G. M.


    Safety and cost information are developed for the conceptual decommissioning of commercial low-level waste (LLW) burial grounds. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are used as reference facilities for the study. The two burial grounds are assumed to have the same site capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology. and hydrology of the two sites are chosen to be typical of real western and eastern sites. Volume 1 (Main Report) contains background information and study results in summary form.

  13. Greybull Sandstone Petroleum Potential on the Crow Indian Reservation, South-Central Montana

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, David A.


    The focus of this project was to explore for stratigraphic traps that may be present in valley-fill sandstone at the top of the Lower Cretaceous Kootenai Formation. This sandstone interval, generally known as the Greybull Sandstone, has been identified along the western edge of the reservation and is a known oil and gas reservoir in the surrounding region. The Greybull Sandstone was chosen as the focus of this research because it is an excellent, well-documented, productive reservoir in adjacent areas, such as Elk Basin; Mosser Dome field, a few miles northwest of the reservation; and several other oil and gas fields in the northern portion of the Bighorn Basin.

  14. The First Paleomagnetic data from the Cambrian basalts of Henrietta Island (De Long Archipelago, Arctic Ocean) (United States)

    Metelkin, D. V.; Zhdanova, A.; Vernikovskiy, V. A.; Matushkin, N. Y.


    Henrietta Island in De Long archipelago (East-Siberian sea) still remains poorly studied geologically but last investigations show that its volcano-sedimentary sequences can help reconstruct tectonic evolution of East Russian Arctic in Early Paleozoic stage. The deposits lying on Precambrian basements are deformed to varying degrees and intruded by mafic dykes.The study was carried out on two basaltic lava flows whose 40Ar/39Ar age is 520.6±9.5 Ma. Previously the age of these basalts was assumed Cretaceous. According to available data the underlaying sediments contain zircons with Cambrian and Ordovician ages but all boundaries between these basalts and other strata are tectonic. So we suppose the age of basalts as Middle Cambrian but more precise geochronological data are required. All magnetic measurements were performed at the Laboratory of Geodynamics and Paleomagnetism of Institute of Petroleum Geology and Geophysics (Novosibirsk). Basalt samples has relatively high magnetic susceptibility values varying from 5x10-4 to 180x10-4SI units. NRM values range is from 3 to 170 mA/m. Petromagnetic parameters including also coercive characteristics point at the good potentially preserving primary magnetization. Stepwise thermal demagnetization permits to isolate characteristic components of magnetization and calculate mean directions in two lava flows: 1. Ds=294.3°, Is=29.1°, K=81.1, α95=5.1; 2. Ds=301.0°, Is=28.3°, K=34.4, α95=7.9). The mean paleomagnetic pole has coordinates: Plat=20.9°, Plong = 42.6°, dp/dm=14.3/7.9. Paleolatitude was defined as 15.3° but the question of the hemisphere for De Long Islands is open yet. In case of south hemisphere in Middle Cambrian according to available paleomagnetic data De Long islands could be placed close to Taimyr margin of Siberia and in case of northern hemisphere they may be located near south (in present-day coordinates) margin of Siberia. The work was supported by grant RFBR 14-05-31399 and Russian Research Fund

  15. Unraveling the redox evolution of the Yangtze Block across the Precambrian/Cambrian transition (United States)

    Diamond, C. W.; Zhang, F.; Chen, Y.; Lyons, T. W.


    Rocks preserved on the South China Craton have played a critical role in refining our understanding of the co-evolution of life and Earth's surface environments in the Late Neoproterozoic and earliest Paleozoic. From the earliest metazoan embryos to the many examples of exceptional preservation throughout the Cambrian Explosion, South China has preserved an outstanding record of animal evolution across this critical transition. Similarly, rocks preserved in South China hold key insights into the changing ocean chemistry that accompanied this extraordinary time. Recent work form Sahoo and others (2016, Geobiology) used redox sensitive metal enrichments in the Ediacaran Doushantuo Formation to demonstrate that the redox state of the Latest Neoproterozoic oceans was highly dynamic, rather than stably oxygenated or anoxic as had both been suggested previously. In an attempt to follow on from this and other studies, we have examined samples from a drill core taken in eastern Guizhou capturing deep-water facies of the Liuchapo and Jiumenchong formations, which contain the Precambrian/Cambrian boundary. In addition to containing the boundary, the sampled interval contains an enigmatic, widespread horizon that is strongly enriched in Ni and Mo. We have taken a multi-proxy approach in our investigation of this layer, the possible implications it has for the strata above and below (i.e., how its presence affects their utility as archives of paleo-redox conditions), and what those strata can tell us about local and global redox conditions during this pivotal time in Earth's history. Our Fe speciation data indicate that conditions were sulfidic at this location throughout the majority of the sampled interval. While redox sensitive metal concentrations are dramatically enriched in the Ni/Mo interval, their concentrations return to modest enrichments above it and continue to decrease upward. This trend suggests that while the conditions that favored extreme enrichment during the

  16. Transient deep-water oxygenation in the early Cambrian Nanhua Basin, South China (United States)

    Cheng, Meng; Li, Chao; Zhou, Lian; Feng, LianJun; Algeo, Thomas J.; Zhang, FeiFei; Romaniello, Stephen; Jin, ChengSheng; Ling, HongFei; Jiang, ShaoYong


    Many late Neoproterozoic to early Cambrian fossils of multicellular eukaryotes, including those of benthic animals, are found preserved under anoxic and even euxinic bottom-water conditions, which is contradictory to the consensus that oxygen is essential to eukaryotes. To investigate this conundrum, we conducted an integrated study of iron speciation, redox-sensitive trace elements, and Mo isotopes (δ98Mo) on the black shale interval of the lower Cambrian Hetang Formation (∼535-521 Ma) at Lantian, South China, in which benthic sponge fossils are abundant in the lower member (LM) but absent in the upper member (UM). Iron speciation data point to uniformly anoxic-ferruginous conditions in the LM and euxinic conditions in the UM, whereas the trace-element and δ98Mo data show greater secular variation in redox conditions. The LM shows higher mean trace element concentrations (Mo: 108 ppm, U: 36 ppm, V: 791 ppm) and lower and more variable δ98Mo (+0.13 to +1.76‰) relative to the UM (Mo: 45 ppm, U: 18 ppm, V: 265 ppm, δ98Mo: +1.59 to +1.67‰), and ratios of redox-sensitive trace element concentrations to total organic carbon are significantly more variable and higher on average in the LM relative to the UM. The appearance of sponge fossils and lower δ98Mo values correlate strongly with gray (i.e., lighter-colored) layers in the LM. These patterns can best be interpreted as recording mainly euxinic conditions throughout deposition of the study units, with more intense background euxinia in the LM relative to the UM, but also with frequent transient oxygenation events in the LM that do not appear in the UM. The transient oxygenation events of the LM led to the initial colonization of the deep Nanhua Basin by sponges, and the termination of these events in the UM caused sponge faunas to disappear until a general rise in O2 levels later in the Cambrian permitted their return to deeper-water habitats. Our study also illustrates that multiple geochemical and

  17. Effect of soil erosion on the long-term stability of FUSRAP near-surface waste-burial sites

    Energy Technology Data Exchange (ETDEWEB)

    Knight, M.J.


    Decontamination of FUSRAP sites could result in the generation of large volumes (in excess of 400,000 m/sup 3/) of low-activity radioactive wastes (primarily contaminated soil and building materials) requiring subsequent disposal. It is likely that near-surface burial will be seriously considered as an option for disposal of these materials. A number of factors - including soil erosion - could adversely affect the long-term stability of a near-surface waste-burial site. The majority of FUSRAP sites are located in the humid eastern United States, where the principal cause of erosion is the action of water. This report examines the effect of soil erosion by water on burial-site stability based on analysis of four hypothetical near-surface burial sites. The Universal Soil Loss Equation was employed to estimate average annual soil loss from burial sites and the 1000-year effects of soil loss on the soil barrier (burial trench cap) placed over low-activity wastes. Results suggest that the land use of the burial site and the slope gradient of the burial trench cap significantly affect the rate of soil erosion. The development of measures limiting the potential land use of a burial site (e.g., mixing large rocks into the burial trench cap) may be required to preserve the integrity of a burial trench for long periods of time.

  18. Effects of sand burial on the survival and growth of two shrubs dominant in different habitats of northern China. (United States)

    Qu, Hao; Zhao, Ha-Lin; Zhao, Xue-Yong; Zuo, Xiao-An; Wang, Shao-Kun; Chen, Min


    Plants that grow in dune ecosystems always suffer from sand burial. Shrubs play implications on the healthy functioning of dune ecosystems due to control blowing sand. However, the survival and growth responses of shrubs to sand burial remain poorly understood. The survival rate and seedling height of two shrubs (Artemisia halodendron and Lespedeza davurica) along with the soil properties under different burial depths were examined in order to reveal the causing ecophysiological attributes of sand burial on shrubs in the desertified region. It was found that A. halodendron can survive a burial depth of 6 cm greater than its seedling height, which is a dominant shrub in mobile dunes with intense burial, whereas a burial depth equivalent to three fourths of its seedling height is detrimental to L. davurica, which is dominant in fixed dunes with less burial. The reasons for the shrub death under sand burial were associated with the physical barrier to vertical growth and the reduction in photosynthetic area. In conclusion, A. halodendron can facilitate the stabilization of mobile dunes because of their high tolerance to the frequent and intensive sand burial, while L. davurica can be beneficial for the recovery process because of their higher survival rates under shallow burial following restoration of mobile dunes.

  19. Lower Cambrian cherts in the northern Tarim Basin, China: implication for the sedimentary environments and tectonic history (United States)

    Zhang, Chunyu; Guan, Shuwei; Wu, Lin; Ren, Rong


    Phosphorus-bearing shale and cherts are widely distributed in the lower Cambrian and record significant information about the basin evolution and the tectonic history. We investigated the Lower Cambrian cherts in the northern Tarim Basin to decode their origin and the tectonic evolution. Field observation shows that chert are layered, layeroid and lens-shaped. Beded chert are underlain, overlain and interbedded with layered dolomite demonstrating that the cherts were deposited in the shallow marine depositional environment, near the storm wave base. Major and rare earth elements geochemistry of lower Cambrian cherts were performed from 2 profiles in the northern Tarim Basin. They are characterized by very high SiO2(average > 90%) low TiO2(≤ 0.01%) and low Al/(Al+Fe+Mn) ratio(avg. 0.26 and 0.16). Samples plotted in the Al-Fe-Mn diagram show that most of the cherts were influenced by hydrothermal fluids. All the cherts have low ΣREE(avg. 22.56 and 19.04), intermediate negative Ce anomaly(avg. 0.59 and 0.58) and slight to intermediated negative Eu anomaly(0.85 and 0.73), low shale-normalized Lan/Ybn values(avg. 0.51 and 0.51)and intermediate Lan/Ybn values (avg. 1.92 and 1.91). These indicate that the cherts were deposited in the open marine modified by the hydrothermal influence. Shallow-water deposition from the field observation contradicted from the deep-water deposition from the geochemistry signature. Combined with previous studies, We suggest that the cherts in the lower Cambrian of the northern Tarim Basin were deposited in a shallow-water shelf influenced by the hydrothermal fluids from the upwelling, carrying the deep water information. The hydrothermal fluids probably came from the South Tianshan Ocean, indicating its openning from the Neoproterozoic rift to the early Cambrian mature ocean.

  20. The Creep Properties of Fine Sandstone under Uniaxial Tensile Stress

    Directory of Open Access Journals (Sweden)

    Jiang Haifei


    Full Text Available A graduated uniaxial direct tensile creep test for fine sandstone is conducted by adopting a custom-designed direct tensile test device for rock. The experiment shows that the tensile creep of fine sandstone has similar creep curve patterns to those of compression creep, while the ratios of the creep strain to the total strain obtained in the tensile tests are substantially higher than those obtained for similar compression tests, which indicates that the creep ability of rock in the tensile process is higher than that in the uniaxial compression process. Based on the elastic modulus in the approximately linear portion of the obtained isochronous stress-strain curves of the tensile creep, the time dependence of the elasticity modulus for the Kelvin model is evaluated, and a revised generalized Kelvin model is obtained by substitution into the generalized Kelvin model. A new viscousplastic model is proposed to describe the accelerated creep properties, and this model is combined in series with the revised generalized Kelvin model to form a new nonlinear viscoelastic-plastic creep model that can describe the properties of attenuation creep, steady creep, and accelerated creep. Comparison of the test and theoretical curves demonstrates that they are nearly identical, which verifies the performance of the model.

  1. Measuring the zeta potential. The relationships with sandstone fineness

    Directory of Open Access Journals (Sweden)

    de Luxán, M. P.


    Full Text Available The application of the zeta potential technique in the area of construction materials and Portland cement is quite recent. The initial research work involved the study of cement suspensions or suspensions of one of the components of cement, such as alite, tricalcium alumínate, in the presence of additives and, more specifically, superplasticizers. The studies of this sort were extended with the mixing of active additions into cement (fly ashes, etc.. The present study discusses the application of siliceous materials (sandstone as a basis of the research into the behaviour of sandstone mortars containing repair products.

    La aplicación de la técnica del potencial zeta en el campo de los materiales de construcción y del cemento portland es muy reciente. Las primeras investigaciones se refieren al estudio de suspensiones de cemento o de alguno de sus compuestos que lo forman como alita, aluminato tricálcico, en presencia de aditivos y, más concretamente, de superfluidificantes. Con la incorporación de adiciones activas al cemento (cenizas volantes,... se amplían los estudios de este tipo de cementos. En este trabajo se considera la aplicación a los materiales silíceos (arenisca como base para la investigación del comportamiento de los morteros de arenisca conteniendo productos de reparación.

  2. Sandstone caves on Venezuelan tepuis: Return to pseudokarst? (United States)

    Aubrecht, R.; Lánczos, T.; Gregor, M.; Schlögl, J.; Šmída, B.; Liščák, P.; Brewer-Carías, Ch.; Vlček, L.


    Venezuelan table mountains (tepuis) host the largest arenite caves in the world. The most frequently used explanation of their origin so far was the "arenization" theory, involving dissolution of quartz cement around the sand grains and subsequent removing of the released grains by water. New research in the two largest arenite cave systems - Churi-Tepui System in Chimanta Massif and Ojos de Cristal System in Roraima Tepui showed that quartz dissolution plays only a minor role in their speleogenesis. Arenites forming the tepuis are not only quartzites but they display a wide range of lithification and breakdown, including also loose sands and sandstones. Speleogenetic processes are mostly concentrated on the beds of unlithified sands which escaped from diagenesis by being sealed by the surrounding perfectly lithified quartzites. Only the so-called "finger-flow" pillars testify to confined diagenetic fluids which flowed in narrow channels, leaving the surrounding arenite uncemented. Another factor which influenced the cave-forming processes by about 30% was lateritization. It affects beds formed of arkosic sandstones and greywackes which show strong dissolution of micas, feldspars and clay minerals, turning then to laterite ("Barro Rojo"). The main prerequisite to rank caves among karst phenomena is dissolution. As the dissolution of silicate minerals other than quartz appears to play not only a volumetrically important role but even a trigger role, these arenitic caves may be ranked as karst.

  3. Why did life develop on the surface of the Earth in the Cambrian?

    Directory of Open Access Journals (Sweden)

    Carlo Doglioni


    Full Text Available Life was limited for most of Earth's history, remaining at a primitive stage and mostly marine until about 0.55 Ga. In the Paleozoic, life eventually exploded and colonized the continental realm. Why had there been such a long period of delayed evolution of life? Early life was dominated by Archaea and Bacteria, which can survive ionizing radiation better than other organisms. The magnetic field preserves the atmosphere, which is the main shield of UV radiation. We explore the hypothesis that the Cambrian explosion of life could have been enabled by the increase of the magnetic field dipole intensity due to the solidification of the inner core, caused by the cooling of the Earth, and the concomitant decrease with time of the high-energy solar flux since the birth of the solar system. Therefore, the two phenomena could be responsible for the growth and thickening of the atmosphere and the development of land surface life.

  4. Petrographic and geochemical composition of kerogen in the Furongian (U. Cambrian) Alum Shale, central Sweden

    DEFF Research Database (Denmark)

    Sanei, H.; Petersen, H. I.; Schovsbo, N. H.


    This paper presents an integrated geochemical and petrological study of the Hällekis-1 core from the Furongian (upper Cambrian) Alum shales in central Sweden to characterise organic matter composition, depositional environment, and potential hydrocarbon generation capability. The results show...... that organic-rich Alum Shale (TOC: 8.9-28.0. wt.%) contains mainly immature, predominantly algal-derived kerogen with unusually reduced hydrocarbon generation potential as suggested by relatively low Hydrogen Index (HI) values (HI: 251-471. mg HC/g TOC) and high degree of aromaticity. In the absence of thermal...... generation of hydrocarbons in these immature shales, the recorded low HI values are explained by an unusual chemistry of the biota during the deposition of the Alum shale accentuated by a high degree of sustained bacterially-mediated degradation (e.g., sulphate reduction), and possibly intense nuclear...

  5. Biostratigraphy of the Furongian (upper Cambrian) Alum Shale Formation at Degerhamn, Öland, Sweden

    DEFF Research Database (Denmark)

    Rasmussen, Bo Wilhelm; Rasmussen, Jan A.; Nielsen, Arne Thorshøj


    The Furongian (upper Cambrian) Alum Shale at Degerhamn, southern Öland, Sweden, has been systematically sampled for macrofossils. Two sections were investigated, one in a large abandoned Alum Shale quarry and one in a nearby road section. The 6.25 m thick succession comprises the Olenus, Parabolina...... in addition to the informal Olenus rotundatus and Sphaerophthalmus modestus zones. The informal Olenus rotundatus biozone is assumed corresponding in age to the Olenus scanicus Chronozone and the informal Sphaerophthalmus modestus biozone is assumed corresponding in age to the Ctenopyge (Mesoctenopyge......) similis Chronozone; S. modestus has not previously been reported from Öland. The uppermost parts of the O. gibbosus, O. truncatus, P. spinulosa and C. tumida zones are reworked. Peltura minor may range into the basal C. linnarssoni Zone; alternatively it is also reworked. Ctenopyge (Ctenopyge) directa...

  6. Raman spectra of a Lower Cambrian ctenophore embryo from southwestern Shaanxi, China (United States)

    Chen, Jun-Yuan; Schopf, J. William; Bottjer, David J.; Zhang, Chen-Yu; Kudryavtsev, Anatoliy B.; Tripathi, Abhishek B.; Wang, Xiu-Qiang; Yang, Yong-Hua; Gao, Xiang; Yang, Ying


    The Early Cambrian (≈540 million years old) Meishucun fossil assemblage of Ningqiang County (Shaanxi Province), China, contains the oldest complex skeletonized organisms known in the geological record. We here report the finding in this assemblage of an exquisitely preserved late-stage embryo of a ctenophore (“comb jelly”), its fine structure documented by confocal laser scanning microscopy and shown by Raman spectroscopy to be composed of carbonaceous kerogen permineralized in apatite. In its spheroidal morphology, the presence of eight comb rows and the absence of tentacles, this embryo resembles an adult ctenophore (Maotianoascus octonarius) known from the immediately younger Chengjiang fauna of Yunnan, China. The oldest ctenophore and the only embryonic comb jelly known from the fossil record, this exceptionally well preserved specimen provides important clues about the early evolution of the phylum Ctenophora and of metazoans in general. PMID:17404242

  7. The anatomy, taphonomy, taxonomy and systematic affinity of Markuelia: Early Cambrian to Early Ordovician scalidophorans (United States)

    Dong, X.-P.; Bengtson, S.; Gostling, N.J.; Cunningham, J.A.; Harvey, T.H.P.; Kouchinsky, A.; Val'Kov, A.K.; Repetski, J.E.; Stampanoni, M.; Marone, F.; Donoghue, P.C.J.


    Markuelia is a vermiform, annulated introvertan animal known as embryonic fossils from the Lower Cambrian to Lower Ordovician. Analysis of an expanded and revised dataset for Introverta shows that the precise position of Markuelia within this clade is dependent on the taxa included. As a result, Markuelia is assigned to the scalidophoran total group to reflect uncertainty as to whether it is a stem-scalidophoran or a stem-priapulid. The taxonomy of the genus is revised to provide an improved taxonomic framework for material assigned to Markuelia. Five species are recognized: M. secunda Val'kov, M. hunanensis Dong and Donoghue, M. lauriei Haug et al., M. spinulifera sp. nov. and M. waloszeki sp. nov. Finally, the preservation of Markuelia is evaluated in the light of both the taphonomy of the fossil embryos themselves and the experimental taphonomy of the priapulid Priapulus caudatus, which has been proposed as both a close relative and an anatomical analogue of Markuelia. ?? The Palaeontological Association.

  8. Thermal identification of clandestine burials: A signature analysis and image classification approach (United States)

    Servello, John A.

    Clandestine burials, the interred human remains of forensic interest, are generally small features located in isolated environments. Typical ground searches can be both time-consuming and dangerous. Thermal remote sensing has been recognized for some time as a possible search strategy for such burials that are in relatively open areas; however, there is a paucity of published research with respect to this application. This project involved image manipulation, the analyses of signatures for "graves" of various depths when compared to an undisturbed background, and the use of image classification techniques to tease out these features. This research demonstrates a relationship between the depth of burial disturbance and the resultant signature. Further, image classification techniques, especially object-oriented algorithms, can be successfully applied to single band thermal imagery. These findings may ultimately decrease burial search times for law enforcement and increase the likelihood of locating clandestine graves.

  9. A new stalked filter-feeder from the middle Cambrian Burgess Shale, British Columbia, Canada.

    Directory of Open Access Journals (Sweden)

    Lorna J O'Brien

    Full Text Available Burgess Shale-type deposits provide invaluable insights into the early evolution of body plans and the ecological structure of Cambrian communities, but a number of species, continue to defy phylogenetic interpretations. Here we extend this list to include a new soft-bodied animal, Siphusauctum gregarium n. gen. and n. sp., from the Tulip Beds (Campsite Cliff Shale Member, Burgess Shale Formation of Mount Stephen (Yoho National Park, British Columbia. With 1,133 specimens collected, S. gregarium is clearly the most abundant animal from this locality.This stalked animal (reaching at least 20 cm in length, has a large ovoid calyx connected to a narrow bilayered stem and a small flattened or bulb-like holdfast. The calyx is enclosed by a flexible sheath with six small openings at the base, and a central terminal anus near the top encircled by indistinct openings. A prominent organ, represented by six radially symmetrical segments with comb-like elements, surrounds an internal body cavity with a large stomach, conical median gut and straight intestine. Siphusauctum gregarium was probably an active filter-feeder, with water passing through the calyx openings, capturing food particles with its comb-like elements. It often occurs in large assemblages on single bedding planes suggesting a gregarious lifestyle, with the animal living in high tier clusters. These were probably buried en masse more or less in-situ by rapid mud flow events.Siphusauctum gregarium resembles Dinomischus, another Cambrian enigmatic stalked animal. Principal points of comparison include a long stem with a calyx containing a visceral mass and bract-like elements, and a similar lifestyle albeit occupying different tiering levels. The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward. Thus, the broader affinities of S. gregarium remain

  10. Trend in groundwater quality near FMD burials in agricultural region, South Korea (United States)

    Lim, Jeong-Won; Lee, Kang-Kun


    After the nation-wide outbreak of Foot and Mouth Disease (FMD) in winter of 2010-2011, thousands of mass burial site had been built all over the country in Korea. Though the burial pits were partially lined with impermeable material, potential threat of leachate leakage was still in concern. In worry of leachate release from those livestock burials during decomposition of carcasses, groundwater samples from wells near the burials were collected and analyzed in between 2011 and 2013. Among the sample locations, 250 wells with monitoring priorities were chosen and had been watched continuously through the years. For trend analysis of groundwater quality, relations between land use types, distances to burial and nitrate concentrations are studied. Types of land use within 300 m radius of each well were investigated. Nitrate concentrations show proportional relations to the area of agricultural activity and inversely proportional to the area of forest. The proportionality decreased with both agricultural and forest area since 2011. When seasonal variation is concerned, slightly stronger proportionality is shown in dry season for both agricultural and forested area. For a qualitative analysis of the trend, non-parametric Kendall test is applied. Especially, regional Kendall test is implemented to find out spatial feature of nitrate concentration. Nitrate concentrations show slow but statistically significant deceasing trend for every well. When the wells are group according to their distances from the nearest burial pit, decreasing trend of nitrate concentration is shown in all groups. However, there was no consistency in significant factor among the groups. Considering the above mentioned results, the groundwater wells near the burials seem to be influence more from agricultural activities near the wells than from the burial leachate. The slow but significant decreasing trend in nitrate concentration is supposed as the result of an increasing governmental interest in

  11. Electrical Resistivity Monitoring for Leachate Distribution at Two Foot-and-Mouth- Disease (FMD) Burial Sites (United States)

    Lee, S.; Kaown, D.; Lee, K.; Leem, K.; Ko, K.


    The main objective of this study was to provide the basic information on leachate distribution with time changes through the electrical resistivity monitoring for a certain period of time in the Foot-and-Mouth-Disease (FMD) burial facilities which is needed to prevent further soil and groundwater contamination and to build an effective plan for stabilization of the burial site. In this study, dipole-dipoles surveys were carried out around two FMD burial sites in Iceon-si, Gyeonggi-do. The FMD burial facility installed at Daewall-myeon is consists of one block but, at Yul-myeon, it is divided into 2 blocks named A and B blocks. Dipole-Dipole surveys with 8 lines at Yul-myeon and 3 lines at Daewall-myeon were carried out. The observed leachate distribution along survey lines was not clearly evident as time passes at Daewall-myeon site, but, at Yul-myeon site, the leachate distribution around the survey lines showed a decrease of resistivity around the burial facility. At and around A and B blocks of Yul-myeon site, interpretations of the survey data show low resistivity zones below 10 Ωm from a depth 3 m to 10 m and such low resistivity zones of the A block are thicker than the B block by about 5~10 m. From the geochemical data and resistivity survey at two FMD burial sites, it is inferred that the groundwater within a 50-meter radius around burial facilities of the Yul-myeon site are contaminated by leachate. The general resistivity distribution around the burial site is seemed affected by the leachate with high electrical conductivity. The detail distribution patterns can be explained by local distributions of soil and weathered rocks and associated leachate flow. This subject is supported by Brain Korea 21 and Korea Ministry of Environment as 'The GAIA Project (173-092-009)'.

  12. Sandstone-body and shale-body dimensions in a braided fluvial system: Salt wash sandstone member (Morrison formation), Garfield County, Utah (United States)

    Robinson, J.W.; McCabea, P.J.


    Excellent three-dimensional exposures of the Upper Jurassic Salt Wash Sandstone Member of the Morrison Formation in the Henry Mountains area of southern Utah allow measurement of the thickness and width of fluvial sandstone and shale bodies from extensive photomosaics. The Salt Wash Sandstone Member is composed of fluvial channel fill, abandoned channel fill, and overbank/flood-plain strata that were deposited on a broad alluvial plain of low-sinuosity, sandy, braided streams flowing northeast. A hierarchy of sandstone and shale bodies in the Salt Wash Sandstone Member includes, in ascending order, trough cross-bedding, fining-upward units/mudstone intraclast conglomerates, singlestory sandstone bodies/basal conglomerate, abandoned channel fill, multistory sandstone bodies, and overbank/flood-plain heterolithic strata. Trough cross-beds have an average width:thickness ratio (W:T) of 8.5:1 in the lower interval of the Salt Wash Sandstone Member and 10.4:1 in the upper interval. Fining-upward units are 0.5-3.0 m thick and 3-11 m wide. Single-story sandstone bodies in the upper interval are wider and thicker than their counterparts in the lower interval, based on average W:T, linear regression analysis, and cumulative relative frequency graphs. Multistory sandstone bodies are composed of two to eight stories, range up to 30 m thick and over 1500 m wide (W:T > 50:1), and are also larger in the upper interval. Heterolithic units between sandstone bodies include abandoned channel fill (W:T = 33:1) and overbank/flood-plain deposits (W:T = 70:1). Understanding W:T ratios from the component parts of an ancient, sandy, braided stream deposit can be applied in several ways to similar strata in other basins; for example, to (1) determine the width of a unit when only the thickness is known, (2) create correlation guidelines and maximum correlation lengths, (3) aid in interpreting the controls on fluvial architecture, and (4) place additional constraints on input variables to

  13. Extent of Stream Burial and Relationships to Watershed Area, Topography, and Impervious Surface Area

    Directory of Open Access Journals (Sweden)

    Roy E. Weitzell


    Full Text Available Stream burial—the routing of streams through culverts, pipes, and concrete lined channels, or simply paving them over—is common during urbanization, and disproportionately affects small, headwater streams. Burial undermines the physical and chemical processes governing life in streams, with consequences for water quality and quantity that may amplify from headwaters to downstream receiving waters. Knowledge of the extent of stream burial is critical for understanding cumulative impacts to stream networks, and for future decision-making allowing for urban development while protecting ecosystem function. We predicted stream burial across the urbanizing Potomac River Basin (USA for each 10-m stream segment in the basin from medium-resolution impervious cover data and training observations obtained from high-resolution aerial photography in a GIS. Results were analyzed across a range in spatial aggregation, including counties and independent cities, small watersheds, and regular spatial grids. Stream burial was generally correlated with total impervious surface area (ISA, with areas exhibiting ISA above 30% often subject to elevated ratios of stream burial. Recurring patterns in burial predictions related to catchment area and topographic slope were also detected. We discuss these results in the context of physiographic constraints on stream location and urban development, including implications for environmental management of aquatic resources.

  14. Different effects of temperature and salinity on permeability reduction by fines migration in Berea sandstone

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus; Riis, Jacob Fabricius


    Hot water injection into geothermal aquifers is considered in order to store energy seasonally. Berea sandstone is often used as a reference formation to study mechanisms that affect permeability in reservoir sandstones. Both heating of the pore fluid and reduction of the pore fluid salinity can...

  15. Tensile and compressive failure of 3D printed and natural sandstones (United States)

    Vogler, D.; Perras, M.; Walsh, S. D. C.; Dombrovski, E.


    Artificial 3D-printed sandstone samples have the potential to replicate the physical characteristics of natural sandstones, allowing the creation of reproducible rock specimens. If successful, such materials could be used to replicate heterogeneous specimens for destructive testing in a number of different configurations and across different test types. In this study, we consider to what degree such artificial samples can match the tensile and compressive failure behavior of natural sandstones. Specifically, 3D printed sandstone samples were subjected to both indirect Brazilian and unconfined compression tests. Two different types of 3D printed and three natural sandstones were tested, comparing their 1) tensile and compressive strength; 2) strain path to failure; 3) failure mode; and 4) fracture geometry after failure. The artificial sandstone samples demonstrated tensile strengths and failure modes similar to those exhibited in weak natural sandstones. Moreover, the ratio of tensile to compressive strength was found to be similar across all materials tested including the 3D printed materials. Finally, the small-scale fracture surface roughness is comparable between artificial and natural specimens of similar tensile strength - suggesting similar grain- and macro-scale failure behavior between the 3D printed and natural sandstone samples.

  16. The Upper Cretaceous Ostravice Sandstone in the Polish sector of the Silesian Nappe, Outer Western Carpathians

    Directory of Open Access Journals (Sweden)

    Cieszkowski Marek


    Full Text Available The Ostravice Sandstone Member was identified and described as a lithostratigraphic unit in the Polish part of the Outer Carpathians. This division occurs in the lowermost part of the Godula Formation, is underlain by variegated deposits of the Mazák Formation or directly by the Barnasiówka and Lhoty formations, and overlain by the Czernichów Member of the Godula Formation. Domination by thick- and very thick-bedded sandstones, conglomeratic sandstones and conglomerates rich in calcareous clasts, mostly of the Štramberk-type limestones, is typical for the Ostravice Sandstone Member. These deposits are widespread between the Moravskoslezské Beskydy Mountains in the Czech Republic and the Ciężkowice Foothills in Poland. The documentation of the Ostravice Sandstone Member occurrence as well as the petrological, sedimentological features, and inventory of the carbonate clasts are presented here.

  17. Geodatabase of the datasets used to represent the four aquifer subunits of the Cambrian-Ordovician aquifer system, Illinois, Iowa, Michigan, Minnesota, and Wisconsin (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase includes spatial datasets that represent the Cambrian-Ordovician aquifer system in the States of Wisconsin, Michigan, Minnesota, Iowa, and Illinois....

  18. Linking south China to northern Australia and India on the margin of Gondwana: Constraints from detrital zircon U‐Pb and Hf isotopes in Cambrian strata

    National Research Council Canada - National Science Library

    Xu, Yajun; Cawood, Peter A; Du, Yuansheng; Hu, Lisha; Yu, Wenchao; Zhu, Yanhui; Li, Wenchao


    Cambrian sedimentary rocks in the southern part of the South China Craton were derived from a source that lay to the south or southeast, beyond the current limits of the craton and which is no longer preserved nearby. U...

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

    Wu, Lin


    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

  20. Identification of sandstone core damage using scanning electron microscopy (United States)

    Ismail, Abdul Razak; Jaafar, Mohd Zaidi; Sulaiman, Wan Rosli Wan; Ismail, Issham; Shiunn, Ng Yinn


    Particles and fluids invasion into the pore spaces causes serious damage to the formation, resulting reduction in petroleum production. In order to prevent permeability damage for a well effectively, the damage mechanisms should be identified. In this study, water-based drilling fluid was compared to oil-based drilling fluids based on microscopic observation. The cores were damaged by several drilling fluid systems. Scanning electron microscope (SEM) was used to observe the damage mechanism caused by the drilling fluids. Results showed that the ester based drilling fluid system caused the most serious damage followed by synthetic oil based system and KCI-polymer system. Fine solids and filtrate migration and emulsion blockage are believed to be the major mechanisms controlling the changes in flow properties for the sandstone samples.

  1. The fracture strength and frictional strength of Weber Sandstone (United States)

    Byerlee, J.D.


    The fracture strength and frictional strength of Weber Sandstone have been measured as a function of confining pressure and pore pressure. Both the fracture strength and the frictional strength obey the law of effective stress, that is, the strength is determined not by the confining pressure alone but by the difference between the confining pressure and the pore pressure. The fracture strength of the rock varies by as much as 20 per cent depending on the cement between the grains, but the frictional strength is independent of lithology. Over the range 0 2 kb, ??=0??5 + 0??6??n. This relationship also holds for other rocks such as gabbro, dunite, serpentinite, granite and limestone. ?? 1975.

  2. Biological transformation of phenols in a sandstone aquifer

    DEFF Research Database (Denmark)

    Broholm, M.; Arvin, E.


    Ammonia liquor with very high concentrations of phenols is known to have leaked into the subsurface at a former coal carbonization plant in the UK. High concentrations of ammonium has been encountered in the groundwater reservoir at the site. In spite of this no significant concentrations...... of phenols are found in the groundwater. In this study the potential for transformation of the phenols in the sandstone aquifer at the site under aerobic, nitrate enriched and ''unaltered'' (limited nitrate available, ironoxides and sulphate available) is investigated in laboratory microcosms. Preliminary...... results reveal complete transformation of phenol, cresols and 3,4-xylenol under all 3 conditions and of 2,5-xylenol under aerobic conditions and 3,5-xylenol under anoxic conditions. The potential for natural attenuation of the phenols in this aquifer appear very promising....

  3. Azimuthal AVO signatures of fractured poroelastic sandstone layers (United States)

    Guo, Zhiqi; Li, Xiang-Yang


    Azimuthal P-wave amplitude variation with offset (AVO) offers a method for the characterisation of a naturally fractured system in a reservoir. This information is important for the analysis of fluid flow during production of, for example, oil, petroleum and natural gas. This paper provides a modelling scheme by incorporating the squirt-flow model for the prediction of velocity dispersion and attenuation with azimuthal reflectivity method for the calculation of frequency-dependent seismic responses. Azimuthal AVO responses from a fractured poroelastic sandstone layer encased within shale are investigated based on the proposed method. Azimuthal reflections are a combination of the dynamic information including the contrast in anisotropic properties, anisotropic propagation and attenuation within the layer, as well as tuning and interferences. Modelling results indicate that seismic responses from the top of the sandstone layer are dominated by reflection coefficients, and show azimuthal variations at far offset which is consistent with conventional azimuthal AVO theory. Reflections from the base, however, demonstrate complex azimuthal variations due to anisotropic propagation and attenuation of transmission waves within the layer. Tuning and interferences further complicate the azimuthal AVO responses for thinner layer thickness. The AVO responses of top reflections show no azimuthal variations for lower fluid mobility, while those of base reflections show visible and stable azimuthal variations even at near and moderate offsets for different fluid mobility. Results also reveal that it would be practical to investigate wavetrains reflected from the fractured layers that are regarded as integrated units, especially for thinner layers where reflections from the top and base are indistinguishable. In addition, near-offset stacked amplitudes of the reflected wavetrains show detectable azimuthal variations, which may offer an initial look at fracture orientations before

  4. Downslope coarsening in aeolian grainflows of the Navajo Sandstone (United States)

    Loope, David B.; Elder, James F.; Sweeney, Mark R.


    Downslope coarsening in grainflows has been observed on present-day dunes and generated in labs, but few previous studies have examined vertical sorting in ancient aeolian grainflows. We studied the grainflow strata of the Jurassic Navajo Sandstone in the southern Utah portion of its outcrop belt from Zion National Park (west) to Coyote Buttes and The Dive (east). At each study site, thick sets of grainflow-dominated cross-strata that were deposited by large transverse dunes comprise the bulk of the Navajo Sandstone. We studied three stratigraphic columns, one per site, composed almost exclusively of aeolian cross-strata. For each column, samples were obtained from one grainflow stratum in each consecutive set of the column, for a total of 139 samples from thirty-two sets of cross-strata. To investigate grading perpendicular to bedding within individual grainflows, we collected fourteen samples from four superimposed grainflow strata at The Dive. Samples were analyzed with a Malvern Mastersizer 2000 laser diffraction particle analyser. The median grain size of grainflow samples ranges from fine sand (164 μm) to coarse sand (617 μm). Using Folk and Ward criteria, samples are well-sorted to moderately-well-sorted. All but one of the twenty-eight sets showed at least slight downslope coarsening, but in general, downslope coarsening was not as well-developed or as consistent as that reported in laboratory subaqueous grainflows. Because coarse sand should be quickly sequestered within preserved cross-strata when bedforms climb, grain-size studies may help to test hypotheses for the stacking of sets of cross-strata.

  5. Crater morphology in sandstone targets: The MEMIN impact parameter study (United States)

    Dufresne, Anja; Poelchau, Michael H.; Kenkmann, Thomas; Deutsch, Alex; Hoerth, Tobias; SchńFer, Frank; Thoma, Klaus


    Hypervelocity (2.5-7.8 km s-1) impact experiments into sandstone were carried out to investigate the influence of projectile velocity and mass, target pore space saturation, target-projectile density contrast, and target layer orientation on crater size and shape. Crater size increases with increasing projectile velocity and mass as well as with increasing target pore space saturation. Craters in water-saturated porous targets are generally shallower and larger in volume and in diameter than craters from equivalent impacts into dry porous sandstone. Morphometric analyses of the resultant craters, 5-40 cm in diameter, reveal features that are characteristic of all of our experimental craters regardless of impact conditions (I) a large central depression within a fragile, light-colored central part, and (II) an outer spallation zone with areas of incipient spallation. Two different mechanical processes, grain fragmentation and intergranular tensile fracturing, are recorded within these crater morphologies. Zone (I) approximates the shape of the transient crater formed by material compression, displacement, comminution, and excavation flow, whereas (II) is the result of intergranular tensile fracturing and spallation. The transient crater dimensions are reconstructed by fitting quadric parabolas to crater profiles from digital elevation models. The dimensions of this transient and of the final crater show the same trends: both increase in volume with increasing impact energy, and with increasing water saturation of the target pore space. The relative size of the transient crater (in percent of the final crater volume) decreases with increasing projectile mass and velocity, signifying a greater contribution of spallation on the final crater size when projectile mass and velocity are increased.

  6. Capillary trapping quantification in sandstones using NMR relaxometry (United States)

    Connolly, Paul R. J.; Vogt, Sarah J.; Iglauer, Stefan; May, Eric F.; Johns, Michael L.


    Capillary trapping of a non-wetting phase arising from two-phase immiscible flow in sedimentary rocks is critical to many geoscience scenarios, including oil and gas recovery, aquifer recharge and, with increasing interest, carbon sequestration. Here we demonstrate the successful use of low field 1H Nuclear Magnetic Resonance [NMR] to quantify capillary trapping; specifically we use transverse relaxation time [T2] time measurements to measure both residual water [wetting phase] content and the surface-to-volume ratio distribution (which is proportional to pore size] of the void space occupied by this residual water. Critically we systematically confirm this relationship between T2 and pore size by quantifying inter-pore magnetic field gradients due to magnetic susceptibility contrast, and demonstrate that our measurements at all water saturations are unaffected. Diffusion in such field gradients can potentially severely distort the T2-pore size relationship, rendering it unusable. Measurements are performed for nitrogen injection into a range of water-saturated sandstone plugs at reservoir conditions. Consistent with a water-wet system, water was preferentially displaced from larger pores while relatively little change was observed in the water occupying smaller pore spaces. The impact of cyclic wetting/non-wetting fluid injection was explored and indicated that such a regime increased non-wetting trapping efficiency by the sequential occupation of the most available larger pores by nitrogen. Finally the replacement of nitrogen by CO2 was considered; this revealed that dissolution of paramagnetic minerals from the sandstone caused by its exposure to carbonic acid reduced the in situ bulk fluid T2 relaxation time on a timescale comparable to our core flooding experiments. The implications of this for the T2-pore size relationship are discussed.

  7. Disc-shaped fossils resembling porpitids (Cnidaria: Hydrozoa) or eldonids from the early Cambrian (Series 2: Stage 4) of western U.S.A.


    Lieberman, Bruce S.; Kurkewicz, Richard; Shinogle, Heather; Kimmig, Julien; MacGabhann, Breandán Anraoi


    The morphology and affinities of newly discovered disc-shaped soft-bodied fossils from the early Cambrian (Series 2: Stage 4, Dyeran) Carrara Formation are discussed. These specimens show some similarity to the Ordovician Discophyllum Hall, 1847; traditionally this taxon had been treated as a fossil porpitid. However, recently it has instead been referred to another clade, the eldonids, which includes the enigmatic Eldonia Walcott, 1911 that was originally described from the Cambrian Burgess ...

  8. The significance of 24-norcholestanes, triaromatic steroids and dinosteroids in oils and Cambrian-Ordovician source rocks from the cratonic region of the Tarim Basin, NW China (United States)

    Li, Meijun; Wang, T.-G.; Lillis, Paul G.; Wang, Chunjiang; Shi, Shengbao


    Two oil families in Ordovician reservoirs from the cratonic region of the Tarim Basin are distinguished by the distribution of regular steranes, triaromatic steroids, norcholestanes and dinosteroids. Oils with relatively lower contents of C28 regular steranes, C26 20S, C26 20R + C27 20S and C27 20R regular triaromatic steroids, dinosteranes, 24-norcholestanes and triaromatic dinosteroids originated from Middle–Upper Ordovician source rocks. In contrast, oils with abnormally high abundances of the above compounds are derived from Cambrian and Lower Ordovician source rocks. Only a few oils have previously been reported to be of Cambrian and Lower Ordovician origin, especially in the east region of the Tarim Basin. This study further reports the discovery of oil accumulations of Cambrian and Lower Ordovician origin in the Tabei and Tazhong Uplifts, which indicates a potential for further discoveries involving Cambrian and Lower Ordovician sourced oils in the Tarim Basin. Dinosteroids in petroleum and ancient sediments are generally thought to be biomarkers for dinoflagellates and 24-norcholestanes for dinoflagellates and diatoms. Therefore, the abnormally high abundance of these compounds in extracts from the organic-rich sediments in the Cambrian and Lower Ordovician and related oils in the cratonic region of the Tarim Basin suggests that phytoplankton algae related to dinoflagellates have appeared and might have flourished in the Tarim Basin during the Cambrian Period. Steroids with less common structural configurations are underutilized and can expand understanding of the early development history of organisms, as well as define petroleum systems.

  9. Noble gas and halogen evidence for the origin of Scandinavian sandstone-hosted Pb-Zn deposits (United States)

    Kendrick, M. A.; Burgess, R.; Harrison, D.; Bjørlykke, A.


    Fluid origins in the sandstone-hosted Pb-Zn class of ore deposit have been investigated in three deposits from Scandinavia; Laisvall, Vassbo and Osen. The deposits studied are hosted by autochthonous Cambrian sandstones that preserve a near original structural relationship to the underlying Precambrian basement, enabling the role of basement interaction to be assessed. Mineral samples have been collected from across the paragenetic sequence: sphalerite, galena, pyrite, fluorite and barite, of impregnation and related joint-hosted mineralization. Fluid-inclusion halogen (Cl, Br and I) and noble gas isotope ( 40Ar, 36Ar, 84Kr) compositions were determined simultaneously by noble gas mass spectrometry of irradiated sample splits. Complementary He isotope analyses are obtained from nonirradiated splits of the same samples. 3He/ 4He values at Laisvall and Osen are highly radiogenic, 0.02 Ra, and the 4He/ 40Ar* ratio extends to values greater than the crustal production value of 5, characteristic of low-temperature crustal fluids. At Vassbo, a slightly elevated 3He/ 4He ratio of 0.1-0.3 Ra is compatible with a very minor mantle component (1%-4%) suggesting a distal source for the basinal brine-dominated fluid. Br/Cl molar ratios 3.2-8.2 × 10 -3 are greater than the present seawater value of 1.54 × 10 -3 and correspond with I/Cl molar ratios in the range 64-1600 × 10 -6. The upper limits of both the I/Cl and Br/Cl values are amongst the highest measured in crustal fluids. Together, the data indicate acquisition of salinity by the evaporation of seawater beyond the point of halite saturation and subsequent fluid interaction with I-rich organic matter in the subsurface. The data are compatible with the independent transport of sulfate and sulfide and indicate that fluids responsible for joint-hosted mineralization were distinct to those responsible for impregnation mineralization. All three deposits preserve fluids with 40Ar/ 36Ar in the range of 6,000-10,000 and fluid

  10. Sedimentary structural element analysis, continuity and permeability of Mesaverde sandstones from the Rifle Gap Area, Colorado. Phase VI report

    Energy Technology Data Exchange (ETDEWEB)

    Hodges, L.T.; Knutson, C.F.; Righter, S.B.


    This field study on sandstone outcrops on the rim of the Piceance Basin had as its prime goals (1) an evaluation of the geometrical properties of the sandstone lenses in the Mesaverde Group, including their length, thickness, continuity, paleocurrent orientations, and crossbed characteristics, and (2) a prognosis of sandstone geometries and orientations at the multiwell site based on the outcrop analysis.

  11. Roman Bronze Vessels From the Late Sarmatian Burial of the Lebedevka Burial-Ground in Western Kazakhstan

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    Treister Mikhail Yuryevich


    Full Text Available This paper is devoted to studying cultural monuments – bronze vessels, a jug and a basin from the barrow no. 1/1967 of the Lebedevka Late Sarmatian burial mound (Western Kazakhstan, dating back to the middle of the 3rd century AD at the latest. These items do not find exact parallels among the bronze vessels of provincial Rome. Although the shape of the jug handle with a curved leaf turned upright between two horizontally arranged swan heads has parallels on the so-called “composite jug with handles” (“gegliederten Henkelkrügen”, the cylindrical form of the jug’s neck peculiar of the glass jugs of allegedly Syrian manufacture of the second half of the 3rd-4th centuries AD is very unusual. Even more unusual is a basin with horizontally bent rim and elaborate handles with pearls on a high narrow stand-ring. The XRF analyses of the Lebedevka jug’s metal revealed that its body and handle were made of a copper-based alloy with very high admixtures of zinc (24-27 % and inconsiderable additions of lead (up to 3 %. A similar alloy was used for manufacturing a vessel in the form of a crouching young negro from Niederbieber. Most objects of provincial Roman import reached Western Kazakhstan via the Bosporan kingdom along the Northern branch of the Silk Road. The above discussed bronze vessels from Lebedevka let suggest, that the nomads could receive some import articles that were brought along the caravan routes leading from Egypt and Syria to the East.

  12. Evaluation of Elevated Tritium Levels in Groundwater Downgradient from the 618-11 Burial Ground Phase I Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.; Smith, R.M.; Williams, B.A.; Thompson, C.J.; Evans, J.C.; Hulstrom, L.C.


    This report describes the results of the preliminary investigation of elevated tritium in groundwater discovered near the 618-11 burial ground, located in the eastern part of the Hanford Site. Tritium in one well downgradient of the burial ground was detected at levels up to 8,140,000 pCi/L. The 618-11 burial ground received a variety of radioactive waste from the 300 Area between 1962 and 1967. The burial ground covers 3.5 hectare (8.6 acre) and contains trenches, large diameter caissons, and vertical pipe storage units. The burial ground was stabilized with a native sediment covering. The Energy Northwest reactor complex was constructed immediately east of the burial ground.

  13. Extensional tectonics and sedimentary response of the Early–Middle Cambrian passive continental margin, Tarim Basin, Northwest China


    Zhiqian Gao; Tailiang Fan


    The fact that several half-grabens and normal faults developed in the Lower–Middle Cambrian of Tazhong (central Tarim Basin) and Bachu areas in Tarim Basin, northwest China, indicates that Tarim Basin was under extensional tectonic setting at this time. The half-grabens occur within a linear zone and the normal faults are arranged in en echelon patterns with gradually increasing displacement eastward. Extensional tectonics resulted in the formation of a passive continental margin in the south...

  14. Siliceous spicules in a vauxiid sponge (Demospongia) from the Kaili Biota(Cambrian Stage 5), Guizhou, South China


    Yang, X.-L.; Zhao, Y.-L.; Babcock, L. E.; Peng, J.


    Fossils of the sponge Angulosuspongia sinensis from calcareous mudstones of the middle and upper part of the Kaili Formation (Cambrian Stage 5) in the Jianhe area of Guizhou province, South China, exhibit an apparently reticulate pattern, characteristic of the Vauxiidae. Energy Dispersive X-Ray Spectrometry (EDS) and Raman spectroscopy analysis indicate the presence of silica in the skeletal elements of these fossils, suggesting that this taxon possessed a skeleton comprised of spicules. This...

  15. Porpitids (Cnidaria: Hydrozoa) from the early Cambrian (Series 2: Stage 4) of Nevada, U.S.A.


    Lieberman, Bruce S.; Kurkewicz, Richard; Shinogle, Heather


    The morphology and affinities of newly discovered soft-bodied fossils from the early Cambrian (Series 2: Stage 4, Dyeran) Carrara Formation that resemble modern and fossil porpitids are discussed. These specimens show substantial similarity to the Ordovician porpitid Discophyllum peltatum Hall, 1847. The status of various Proterozoic and Phanerozoic taxa previously referred to porpitids is also briefly considered. To verify that the specimens were not dubio- or pseudofossils, elemental mappin...

  16. Buried Alive: The Behavioural Response of the Mussels, Modiolus modiolus and Mytilus edulis to Sudden Burial by Sediment.

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    Zoë L Hutchison

    Full Text Available Sedimentation in the sea occurs through natural processes, such as wave and tidal action, which can be exacerbated during storms and floods. Changes in terrestrial land use, marine aggregate extraction, dredging, drilling and mining are known to result in substantial sediment deposition. Research suggests that deposition will also occur due to the modern development of marine renewable energy. The response to individual burial under three depths of sediment, three sediment fractions and five burial durations was investigated in two mussel species, Modiolus modiolus and Mytilus edulis in specialist mesocosms. Both mussel species showed substantial mortality, which increased with duration of burial and burial by finer sediment fractions. M. modiolus was better able to survive short periods of burial than M. edulis, but at longer durations mortality was more pronounced. No mortality was observed in M. modiolus in burial durations of eight days or less but by 16 days of burial, over 50% cumulative mortality occurred. Under variable temperature regimes, M. edulis mortality increased from 20% at 8°C to over 60% at 14.5 and 20°C. Only M. edulis was able to emerge from burial, facilitated by increased byssus production, laid mostly on vertical surfaces but also on sediment particles. Emergence was higher from coarse sediment and shallow burials. Byssus production in M. edulis was not related to the condition index of the mussels. Results suggest that even marginal burial would result in mortality and be more pronounced in warm summer periods. Our results suggest that in the event of burial, adult M. modiolus would not be able to emerge from burial unless local hydrodynamics assist, whereas a small proportion of M. edulis may regain contact with the sediment water interface. The physiological stress resulting in mortality, contribution of local hydrodynamics to survival and other ecological pressures such as mussels existing in aggregations, are

  17. Discussions on the sedimentary-tectonic event and tectonic setting of the North Tarim Basin in Cryogenian-Cambrian (United States)

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


    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).

  18. Ichnologic evidence of a Cambrian age in the southern Amazon Craton: Implications for the onset of the Western Gondwana history (United States)

    Santos, Hudson P.; Mángano, M. Gabriela; Soares, Joelson L.; Nogueira, Afonso C. R.; Bandeira, José; Rudnitzki, Isaac D.


    Colonization of the infaunal ecospace by burrowing bilaterians is one of the most important behavioral innovations during the Ediacaran-Cambrian transition. The establishment of vertical burrows by suspension feeders in high-energy nearshore settings during Cambrian Age 2 is reflected by the appearance of the Skolithos Ichnofacies. For the first time, unquestionable vertical burrows typical of the Skolithos Ichnofacies, such as Skolithos linearis, Diplocraterion parallelum and Arenicolites isp., are recorded from nearshore siliciclastic deposits of the Raizama Formation, southeastern Amazon Craton, Brazil. Integration of ichnologic and sedimentologic datasets suggests that these trace fossils record colonization of high-energy and well-oxygenated nearshore sandy environments. Chronostratigraphically, the presence of these vertical burrows indicates an age not older than early Cambrian for the Raizama Formation, which traditionally has been regarded as Ediacaran. Therefore, the Raizama ichnofauna illustrates the advent of modern Phanerozoic ecology marked by the Agronomic Revolution. The discovery of the Skolithos Ichnofacies in these shallow-marine strata suggests possible connections between some central Western Gondwana basins.

  19. Sequence stratigraphy of the Middle Cambrian Daegi Formation (Korea), and its bearing on the regional stratigraphic correlation (United States)

    Sim, Min Sub; Lee, Yong Il


    The sediments that comprise the Middle Cambrian Daegi Formation in eastern central Korea are interpreted to have been deposited in a carbonate ramp setting. The Daegi Formation consists of nine lithofacies; argillaceous rock, ribbon rock, oolitic limestone, skeletal limestone, microbial limestone, intraclastic limestone, micritic limestone, bioturbated limestone and crystalline limestone, which are grouped into three facies associations presenting, from base up, outer ramp, grain shoal and inner ramp facies associations. Two depositional sequences can be distinguished in the Daegi Formation. Sequence 1 in the lower part of the Daegi Formation comprises a lower transgressive systems tract (TST) and an upper highstand systems tract (HST). The TST consists of terrigenous deposits with subordinate limestones, while the HST contains various types of limestone. Sequence 2 comprises the upper half of the Daegi Formation and was deposited during a TST. The sequence stratigraphic analysis of the Daegi Formation suggests that the sediments were deposited during one 3rd-order sea-level change, during the middle to late Middle Cambrian. The sequence stratigraphic framework of the Daegi Formation can be excellently correlated with coeval deposits in North China, the Zhangxia and the lower part of the overlying Gushan formations, which belong to the same tectonic block as the Korean Peninsula, the Sino-Korean Block (SKB). The almost identical sequence stratigraphic frameworks in two separate basins suggest that the sequence stratigraphic development on the SKB was mainly influenced by eustatic changes during the Middle Cambrian.

  20. Pan African Collisional Tectonics Along the Moroccan West African Craton Continued to Ediacaran-Cambrian Boundary (United States)

    Hefferan, K. P.; Samson, S. D.; Rice, K.; Soulaimani, A.


    Precision geochronologic dating and field mapping in the Anti-Atlas Mountains of Morocco document a Neoproterozoic Pan African orogenic cycle consisting of three distinct orogenic events: Iriri-Tichibanine orogeny (760-700 Ma), Bou Azzer orogeny (680-640 Ma) and the WACadomian orogeny (620 Ma to either 555 or 544 Ma). The Iriri-Tichibanine and Bou Azzer orogenies involved northward directed subduction beneath island arc volcanic terranes. These orogenic events generated calc-alkaline magmatism and supra-subduction zone ophiolites exposed in the Bou Azzer and Siroua erosional inliers. The WACadomian orogeny involved subduction and collision of the Cadomia arc complex with the West African Craton and generation of clastic sedimentary basins. The termination of the WACadomian orogeny has been the subject of debate as calc-alkaline to high K magmatism and folding continued to 544 Ma: Was 620-544 Ma calc-alkaline to high K magmatism and clastic basin development due to a) continental rift basin tectonics or b) southward directed subduction and collisional tectonics with associated back arc basin tectonism? We present field and geochemical data supporting the continuation of subduction-collisional tectonics to the Ediacaran-Cambrian boundary 544 Ma. Field mapping in the Central Anti-Atlas (Agadir Melloul) clearly documents an angular unconformity between Ouarzazate Group and Adoudounian limestones (N 30°31'28.91", W07°48'29.12"). Volcaniclastic rocks of Ouarzazate Group (615-545 Ma) are clearly folded and unconformably overlain by Adoudou Formation (541-529 Ma) limestones to the north. Geochemical discrimination diagrams on Latest Neoproterozoic calc-alkaline to high K igneous rocks throughout the Anti-Atlas plot in subduction and collisional arc magma domains. Back arc basin tectonism is likely responsible for localized extensional basins but continental rift tectonics and passive margin sedimentation did not begin in the Anti-Atlas Mountains until Early

  1. Environmental upheavals of the Ediacaran period and the Cambrian “explosion” of animal life

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    Grant M. Young


    Full Text Available The second half of the Ediacaran period began with a large impact – the Acraman impact in South Australia, which was accompanied by a negative δ13Ccarb anomaly and an extinction-radiation event involving acritarchs. A few million years later (∼570 Ma? there was a second, deeper and longer-lived world-wide δ13Ccarb anomaly (the Shuram anomaly which coincides with extinction of the acanthomorphic acritarchs. Wide distribution of the Shuram event is exemplified by stratigraphic sections from South Australia, Oman, southern California and South China. The widespread anomaly has been tentatively attributed to a marine impact. During recovery from the Shuram event the enigmatic Ediacaran biota achieved its zenith, only to be extirpated and replaced by a polyphyletic assemblage of shelly animals in what is known as the Cambrian “explosion”. This extinction-radiation cycle was preceded by glaciation, another δ13Ccarb excursion and the highest 87Sr/86Sr values known from marine carbonates. These high Sr ratios have been linked to weathering of extensive tracts of continental crust that were elevated during amalgamation of the supercontinent Gondwana. Introduction of essential nutrients to the oceans would have promoted biological production of oxygen and provided P and Ca for the important skeletonization that characterizes the Cambrian “explosion” and caused a quantum leap in the preservation potential of animal remains. Turbulent events of the last 50 million years of Precambrian time include three glaciations, two large impacts and a massive orogenic episode. These dramatic environmental upheavals are held responsible for three consecutive extinction-radiation cycles that culminated in the appearance of a diverse array of shelly fossils. Various lines of evidence suggest that the metazoans have deep roots so that they too may have been subjected to the environmental pressures of the late Ediacaran period clearly illustrated by

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

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    Anna Xu


    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

  3. Recovery of macrobenthic assemblages following experimental sand burial

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    José J. Barrón


    Full Text Available This research was supported by a fund provided by the Instituto de Ciencias del Mar y Limnología (UNAM and a fund provided to Celia Olabarria in 2004 and 2005 by the University of Vigo for overseas short stays.AbstractPeriodic inundation by sand is a very common feature of rocky coasts throughout the world. Even so, there have been few direct observations or experiments to investigate the role of sediments on intertidal rocky shores. We designed a field experiment in Mazatlán Bay, Mexico, to test the initial impact and subsequent recovery of intertidal macrobenthic assemblages exposed to sand burial at two sites of varying wave exposure. Both sites supported different natural assemblages. Treatment plots for the addition of sediment and control plots (50 × 50 cm, separated by at least 1.5 m, were randomly placed across the mid-water tidal level. The initial response of the resident macrobenthos and the subsequent recolonization was monitored over a period of 95 days. The main effect of sediment deposition at both sites was mortality and removal of biota due to smothering. The recovery process was rapid and may in part have been the result of the mechanism by which the small, disturbed patches were recolonized. Most of the invertebrates colonized the patches as adults; several seaweeds exhibited vegetative growth as the major mechanism of colonization (e.g., Ulva lactuca Linnaeus, 1753, Amphiroa valonioides Yendo, 1902 and Chaetomorpha antennina (Borgensen Kutzing, 1849. The rate of recovery varied between the sites, however. Recovery of species numbers proceeded quickly at the sheltered site (day 7, but took 95 days at the exposed site. In contrast, biomass reached control levels by day 45 at the sheltered site, but already by day 15 at the exposed site. By day 95, the assemblages recovered to 83.5% and 81% similarity with the controls at the sheltered and exposed sites respectively. Although differences in wave exposure could be very

  4. Reservoir assessment of the Nubian sandstone reservoir in South Central Gulf of Suez, Egypt (United States)

    El-Gendy, Nader; Barakat, Moataz; Abdallah, Hamed


    The Gulf of Suez is considered as one of the most important petroleum provinces in Egypt and contains the Saqqara and Edfu oil fields located in the South Central portion of the Gulf of Suez. The Nubian sandstone reservoir in the Gulf of Suez basin is well known for its great capability to store and produce large volumes of hydrocarbons. The Nubian sandstone overlies basement rocks throughout most of the Gulf of Suez region. It consists of a sequence of sandstones and shales of Paleozoic to Cretaceous age. The Nubian sandstone intersected in most wells has excellent reservoir characteristics. Its porosity is controlled by sedimentation style and diagenesis. The cementation materials are mainly kaolinite and quartz overgrowths. The permeability of the Nubian sandstone is mainly controlled by grain size, sorting, porosity and clay content especially kaolinite and decreases with increase of kaolinite. The permeability of the Nubian Sandstone is evaluated using the Nuclear Magnetic Resonance (NMR technology) and formation pressure data in addition to the conventional logs and the results were calibrated using core data. In this work, the Nubian sandstone was investigated and evaluated using complete suites of conventional and advanced logging techniques to understand its reservoir characteristics which have impact on economics of oil recovery. The Nubian reservoir has a complicated wettability nature which affects the petrophysical evaluation and reservoir productivity. So, understanding the reservoir wettability is very important for managing well performance, productivity and oil recovery.

  5. Awn length variation and its effect on dispersal unit burial of Trachypogon spicatus (Poaceae). (United States)

    Johnson, Erica E; Baruch, Zdravko


    Trachypogon spicatus, formerly known as Trachypogon plumosus, is a dominant grass in some savannas of Northern South America. Its dispersal unit, like many other species of the Andropogoneae tribe, bears a hygroscopic awn which facilitates its establishment in favorable microsites. Some authors have previously proposed that there is a positive correlation between awn length and dispersal unit burial, and that this relationship increases the probability of seed survival in the event of a fire, since soil acts as insulator. In this study we experimentally tested this relationship for T. spicatus. A total of 192 diaspores were placed in randomized blocks, in aluminum trays filled with soil under greenhouse conditions. Diaspores were sprayed with water daily for a month to guarantee awn movement; on the last day of the experiment, they were sprayed with red aerosol paint to determine burial depth. The effects of awn length, presence of caryopses, and presence of a pivot for the passive segment of the awn on diaspore burial were evaluated. Germination viability was tested using a tetrazolium salt test for 35 caryopses. No significant differences in diaspore burial were observed between diaspores with and without caryopses (F(2,126) = 0.034, p=0.853). A positive correlation between awn length and diaspore burial was observed only if the passive awn lacked a pivot (r(66)=0.394, p<0.05). Diaspores whose awns had a pivot point achieved significantly deeper burial distances than their counterparts (F(2,126)=7.063, p=0.005). Viability test found that 0% of caryopses tested were able to germinate; this is possibly due to the time difference between sampling and testing. We considered the presence or absence of caryopsis as an important factor, since previous studies have not yet considered it and the high production of sterile diaspores in grasses. These results suggest that the physical mechanism behind T. spicatus diaspore burial is awn torque. This would explain why our

  6. Retrodiction of secular variations in deep-sea CaCO3 burial during the Cenozoic (United States)

    Boudreau, Bernard P.; Luo, Yiming


    Deep-sea sediments record changes in oceanic carbonate chemistry and CaCO3 sedimentation rate through temporal variations in the total burial of CaCO3 and the position of the carbonate snowline, i.e., the ocean depth at which CaCO3-free sediments are first recorded. This paper links mathematically secular changes in snowline to those in the burial rate through a set of relatively simple equations. When the available Cenozoic deep-sea burial records are employed to predict secular variations in snowline, the process fails at some time in the past, indicating that these records are not consistent with each other. The burial records are more likely the source of this problem, as they involve far more uncertainties than the snowline records. As a consequence, we introduce a method for estimating carbonate burial through the use of a canonical CaCO3-depth profile, which can respond dynamically to secular changes in carbonate sedimentation and the positions of both the snowline and the carbonate saturation horizon. The resulting synthetic CaCO3 burial record is consistent with snowline records and indicates that the burial rates offered by Davies and Worsley (1981) are generally too high, with highly questionable maxima at 25 and 47 Ma BP. Our estimates of burial are more consistent with the range advanced by Mackenzie and Morse (1992); nevertheless, our results differ from the latter with respect to timing and magnitude of the variations. Our approach allows simultaneous calculation of the mean carbonate ion concentration of the deep sea. We find that carbonate-ion levels fell through the Cenozoic and are similar to those calculated by Tyrrell and Zeebe (2004), using a different model. Secular variations in CaCO3 burial are found to be primarily driven by changes in the Ca2+-CO3 2 - ion product within the bottom-waters, with an increase in the sedimentation rate of CaCO3 of secondary importance over the Cenozoic.

  7. [Effect of shifting sand burial on evaporation reduction and salt restraint under saline water irrigation in extremely arid region]. (United States)

    Zhang, Jian-Guo; Zhao, Ying; Xu, Xin-Wen; Lei, Jia-Qiang; Li, Sheng-Yu; Wang, Yong-Dong


    The Taklimakan Desert Highway Shelterbelt is drip-irrigated with high saline groundwater (2.58-29.70 g x L(-1)), and shifting sand burial and water-salt stress are most common and serious problems in this region. So it is of great importance to study the effect of shifting sand burial on soil moisture evaporation, salt accumulation and their distribution for water saving, salinity restraint, and suitable utilization of local land and water resources. In this study, Micro-Lysimeters (MLS) were used to investigate dynamics of soil moisture and salt under different thicknesses of sand burial (1, 2, 3, 4, and 5 cm), and field control experiments of drip-irrigation were also carried out to investigate soil moisture and salt distribution under different thicknesses of shifting sand burial (5, 10, 15, 20, 25, 30, 35, and 40 cm). The soil daily and cumulative evaporation decreased with the increase of sand burial thickness in MLS, cumulative evaporation decreased by 2.5%-13.7% compared with control. And evaporative inhibiting efficiency increased with sand burial thickness, evaporative inhibiting efficiency of 1-5 cm sand burial was 16.7%-79.0%. Final soil moisture content beneath the interface of sand burial increased with sand burial thickness, and it increased by 2.5%-13.7% than control. The topsoil EC of shifting sand in MLS decreased by 1.19-6.00 mS x cm(-1) with the increasing sand burial thickness, whereas soil salt content beneath the interface in MLS increased and amplitude of the topsoil salt content was higher than that of the subsoil. Under drip-irrigation with saline groundwater, average soil moisture beneath the interface of shifting sand burial increased by 0.4% -2.0% compare with control, and the highest value of EC was 7.77 mS x cm(-1) when the sand burial thickness was 10 cm. The trend of salt accumulation content at shifting sand surface increased firstly, and then decreased with the increasing sand burial thickness. Soil salt contents beneath the

  8. {sup 57}Fe Moessbauer and X-ray characterisation of sandstones

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    Mulaba-Bafubiandi, A. F. [University of Johannesburg, Mineral Processing and Technology Research Centre, Department of Metallurgy, School of Mining, Metallurgy and Chemical Engineering, Faculty of Engineering and The Built Environment (South Africa); Waanders, F. B., E-mail: [North West University, School of Chemical and Minerals Engineering (South Africa)


    Sandstones from the Free State province in South Africa have been mined and processed mainly by small scale and artisanal miners in the rural areas. In the present investigation basic fire proof and water absorption tests, X-ray and {gamma}-ray based characterisation techniques were used to study the sandstones. The collected samples were grouped according to their apparent colour in day light conditions and the elemental analysis showed the presence of a high amount of oxygen (>52%) and silicon (>38%) with Mn, Al, Fe and Ca as major elements in proportions related to the colour distribution of the various sandstones. The uniaxial compressive stress was found to be the highest (56 MPa) for the greyish sandstone and the lowest (8 MPa) for the white sandstone sample, also associated with the lowest (Al+Fe)/Si value of 0.082. The humidity test showed that the 6 % water absorption was lower than the recommended ASTM value of 8 %. The sandstone samples were also subjected to various high temperatures to simulate possible fire conditions and it was found that the non alteration of the mineral species might be one of the reasons why the sandstones are regarded as the most refractory amongst the building materials typically used. Moessbauer spectroscopy revealed that iron is present in all the sandstones, mainly as Fe{sup 3 + } with the black sandstone showing an additional presence of 3 % Fe{sup 2 + } indicating that a higher iron content coupled to higher silicon content, contributes to an increase in the uniaxial compressive strength.

  9. Fracturing and Damage to Sandstone Under Coupling Effects of Chemical Corrosion and Freeze-Thaw Cycles (United States)

    Han, Tielin; Shi, Junping; Cao, Xiaoshan


    Rapid freeze-thaw (FT) cycles were adopted to explore the damage deterioration mechanism and mechanical properties of sandstone specimens under the coupling effects of different chemical solutions and FT cycles. The variation regularities of the FT cycles and physical and mechanical properties of sandstone specimens immersed in different chemical solutions were analyzed by using sandstone sampled from a Chinese riverbank slope. The damage variable based on porosity variation was used in the quantitative analysis of the damage to the sandstone under the coupling effects of chemical corrosion and FT cycles. Experimental results showed that the sandstone specimens weakened substantially under those effects. Their fracture toughness K IC, splitting tensile strength, and compressive strength showed a similar deteriorating trend with various numbers of FT cycles. However, a difference exists in the deterioration degree of their mechanical parameters, i.e., the deterioration degree of their fracture toughness K IC is the greatest followed by that of splitting tensile strength, and that of compressive strength is relatively small. Strong acid solutions may aggravate the deterioration of FT damage in sandstones, but at the early stage of the experiment, strong alkaline solutions inhibited sandstone damage deterioration. However, the inhibiting effect disappeared when the number of FT cycles exceeded 25. The different chemical solutions had a different effect on the FT damage degree of the sandstone specimens; for example, SO4 2- ions had a greater effect on FT damage than did HCO3 - ions. Water-chemical solutions and FT cycles promote each other in deteriorating rocks and simultaneously affect the damage deterioration degree of sandstones.

  10. Composition, provenance and source weathering of Mesozoic sandstones from Western-Central Mediterranean Alpine Chains (United States)

    Perri, F.


    Forty-two Mesozoic sandstone samples from three different sedimentary successions of the Internal Domains along the Western-Central Mediterranean Alpine Chains (Betic Cordillera, Rif Chain and Calabria-Peloritani Arc) were chemically analyzed to characterize their composition and the degree of weathering in the source area(s). The Rif Chain sandstones have SiO2 contents higher than those of the Calabria-Peloritani Arc and Betic Cordillera sandstones, whereas Al2O3 contents are higher in the Calabria-Peloritani Arc sandstones rather than in the Rif Chain and Betic Cordillera sandstones. The indices of compositional variability (ICV) of the studied samples are generally less than 1, suggesting that the samples are compositionally mature and were likely dominated by recycling. Recycling processes are also shown by the Al-Zr-Ti diagram indicating zircon addition and, thus, recycling processes. The Chemical Index of Alteration (CIA) values are quite homogeneous for the Calabria-Peloritani Arc (mean = 76) and Betic Cordillera sandstones (mean = 55), whereas the Rif Chain sandstones are characterized by CIA values ranging from 54 to 76. The CIW and PIA values are high for all the studied sandstones indicating intense weathering at the source areas. The different values of weathering rates among the studied sandstones may be related to variations of paleoclimatic conditions during the Mesozoic, that further favored recycling processes. Thus, these differences among the studied samples, may be related to an increase in continental palaeoweathering conditions and sediment recycling effects from the Middle Triassic to the earliest Jurassic due to rising humidity. In addition, regional tectonic movements promoted structural changes that allowed sedimentary recycling and subsidence, which in turn caused diagenetic K-metasomatism. These processes could significantly affect the CIW and PIA weathering indices, which likely monitor a cumulative effect, including several cycles of

  11. A simple model of pressure build-up caused by porosity reduction during burial

    Energy Technology Data Exchange (ETDEWEB)

    Wangen, M.


    The report relates to a study done on fluid pressure build-up owing to porosity reduction in sedimentary basins during burial. The model assumes that the void ratio decreases exponentially with depth, and that the permeability is proportional to the void ratio to an arbitrary exponent. Simple analytical solutions are obtained for the Darcy velocity and the fluid excess pressure The pressure build-up during burial is studied with these solutions, and it is found to be inversely proportional to the gravity number. The importance of the permeability exponents on the fluid pressure is studied as well. Gravity numbers much less than 1 are shown to yield high access pressures during burial, A reasonable approximation for the maximum Darcy velocity is found to be the product of the surface void ratio and the burial rate. Hydro-fracturing is discussed in relation to the pressure build-up, and cases characterised by gravity numbers much less than 1 are found to yield hydro-fracturing over large depth ranges. It is suggested that the average permeability of hydro-fractured sediments during burial corresponds to the gravity number equal to 1. 28 refs., 8 figs.

  12. Facies architecture of the Bluejacket Sandstone in the Eufaula Lake area, Oklahoma: Implications for the reservoir characterization of the Bartlesville Sandstone

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Liangmiao; Yang, Kexian [Univ. of Tulsa, OK (United States)


    Outcrop studies of the Bluejacket Sandstone (Middle Pennsylvanian) provide significant insights to reservoir architecture of the subsurface equivalent Bartlesville Sandstone. Quarry walls and road cuts in the Lake Eufaula area offer excellent exposures for detailed facies architectural investigations using high-precision surveying, photo mosaics. Directional minipermeameter measurements are being conducted. Subsurface studies include conventional logs, borehole image log, and core data. Reservoir architectures are reconstructed in four hierarchical levels: multi-storey sandstone, i.e. discrete genetic intervals; individual discrete genetic interval; facies within a discrete genetic interval; and lateral accretion bar deposits. In both outcrop and subsurface, the Bluejacket (Bartlesville) Sandstone comprises two distinctive architectures: a lower braided fluvial and an upper meandering fluvial. Braided fluvial deposits are typically 30 to 80 ft thick, and are laterally persistent filling an incised valley wider than the largest producing fields. The lower contact is irregular with local relief of 50 ft. The braided-fluvial deposits consist of 100-400-ft wide, 5-15-ft thick channel-fill elements. Each channel-fill interval is limited laterally by an erosional contact or overbank deposits, and is separated vertically by discontinuous mudstones or highly concentrated mudstone interclast lag conglomerates. Low-angle parallel-stratified or trough cross-stratified medium- to coarse-grained sandstones volumetrically dominate. This section has a blocky well log profile. Meandering fluvial deposits are typically 100 to 150 ft thick and comprise multiple discrete genetic intervals.

  13. Study on Three Point Bending Features of Sandstone Based on Acoustic Emission (United States)

    Li, Kexuan; Li, Tie


    The three-point bending experiment of sandstone from a coal mine roof under different loading rates based on acoustic emission was carried out. Through analyzing the AE phenomenon, found that the sandstone fracture is brittle fracture. The number of AE counts under low loading speed is more than it under high loading speed, indicated that internal crack is more fully occurred and expanded at low loading speed. The AE energy presents as solitary earthquake type. The flexural strength of sandstone is not high, the failure load and flexural strength increase with the increasing of loading speed, and then decline gradually after reaching the extreme value.

  14. Two scale analysis applied to low permeability sandstones (United States)

    Davy, Catherine; Song, Yang; Nguyen Kim, Thang; Adler, Pierre


    Low permeability materials are often composed of several pore structures of various scales, which are superposed one to another. It is often impossible to measure and to determine the macroscopic properties in one step. In the low permeability sandstones that we consider, the pore space is essentially made of micro-cracks between grains. These fissures are two dimensional structures, which aperture is roughly on the order of one micron. On the grain scale, i.e., on the scale of 1 mm, the fissures form a network. These two structures can be measured by using two different tools [1]. The density of the fissure networks is estimated by trace measurements on the two dimensional images provided by classical 2D Scanning Electron Microscopy (SEM) with a pixel size of 2.2 micron. The three dimensional geometry of the fissures is measured by X-Ray micro-tomography (micro-CT) in the laboratory, with a voxel size of 0.6x0.6x0.6microns3. The macroscopic permeability is calculated in two steps. On the small scale, the fracture transmissivity is calculated by solving the Stokes equation on several portions of the measured fissures by micro-CT. On the large scale, the density of the fissures is estimated by three different means based on the number of intersections with scanlines, on the surface density of fissures and on the intersections between fissures per unit surface. These three means show that the network is relatively isotropic and they provide very close estimations of the density. Then, a general formula derived from systematic numerical computations [2] is used to derive the macroscopic dimensionless permeability which is proportional to the fracture transmissivity. The combination of the two previous results yields the dimensional macroscopic permeability which is found to be in acceptable agreement with the experimental measurements. Some extensions of these preliminary works will be presented as a tentative conclusion. References [1] Z. Duan, C. A. Davy, F

  15. Bilaterians of the Precambrian—Cambrian transition and the annelid—arthropod relationship (United States)

    Valentine, James W.


    The Late Proterozoic fossil record contains the remains of animals that may represent a grade of organization not found among living metazoans. These forms were segmented and large enough to require a hemocoel, yet evidently were not capable of forming penetrating burrows, which are essentially absent from contemporaneous sediments containing locally common but chiefly horizontal trace fossils. As has been noted, there is no evidence that Late Proterozoic invertebrates possessed a coelom suited for peristaltic burrowing. Therefore, the annelidan body plan had probably not appeared. It is not implausible, however, that coelomic spaces in the form of ducts or organ sacs were present in Late Proterozoic segmented forms. Uniramians, some of which employ the hemocoel hydrostatically in lobopodal locomotion, may be allied to segmented hemocoelic forms not unlike sprigginids. Coelomic spaces may have been exploited in some protoarthropod lineages to enhance pedal-wave locomotion, but probably there are no eucoelomic forms in arthropodan ancestry. Annelids may represent an early divergent branch of seriated worms, perhaps rather nemertine-like at first, that developed eucoelomic compartments only in Cambrian time. The extinct grade is most likely to have arisen from flatworm-like ancestors. Of all the proposed phylogenies examined, only that of Manton closely anticipates these interpretations of the early metazoan fossil record. Images PMID:16594022

  16. Differing styles of stromatolite diagenesis: Implication for stromatolite origin and diagenesis of Upper Cambrian peritidal carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Glumac, B.; Walker, K.R. (Univ. of Tennessee, Knoxville, TN (United States). Dept. of Geological Sciences)


    Stromatolite morphology and the characteristics of associated sediments are commonly used to discern environments of stromatolite formation. In this study, the authors suggest that study of stromatolite diagenesis allows a better understanding of the origin of stromatolites and the diagenesis of carbonate sediments. The Upper Cambrian Maynardville Formation of the Conasauga Group in Tennessee consists of subtidal and peritidal carbonate lithologies. These contain several types of cryptalgal structures: (1) cryptalgal (microbial) laminites; (2) laterally linked hemispheroidal stromatolites; (3) stacked hemispheroidal stromatolites; (4) columnar stromatolites; (5) digitate stromatolites; and (6) thrombolites. The succession from 1 to 6 above represents increasing water turbulence from supratidal to upper subtidal depositional environments. Stromatolites form by two major mechanisms: (1) the trapping of sediment grains by microbial mats; and (2) the calcification of cyanobacterial sheaths under favorable environmental conditions. These two mechanisms of formation can be discerned in the fossil record based on stromatolite response to diagenesis. Early calcification by cyanobacteria reduces the susceptibility of stromatolites to dolomitization. Biogenic calcification was not pervasive during formation of dolomitized stromatolites due to conditions of periodic emergence and increased salinity. Under these conditions, dolomitization was an important diagenetic process that preceded early calcification. The authors interpret dolomitization to be penecontemporaneous with deposition. The results of this study confirm that differing styles of stromatolite diagenesis can be used as indicators of stromatolite origin and to aid in reconstructing the diagenetic processes in peritidal carbonates.

  17. Cambrian cinctan echinoderms shed light on feeding in the ancestral deuterostome. (United States)

    Rahman, Imran A; Zamora, Samuel; Falkingham, Peter L; Phillips, Jeremy C


    Reconstructing the feeding mode of the latest common ancestor of deuterostomes is key to elucidating the early evolution of feeding in chordates and allied phyla; however, it is debated whether the ancestral deuterostome was a tentaculate feeder or a pharyngeal filter feeder. To address this, we evaluated the hydrodynamics of feeding in a group of fossil stem-group echinoderms (cinctans) using computational fluid dynamics. We simulated water flow past three-dimensional digital models of a Cambrian fossil cinctan in a range of possible life positions, adopting both passive tentacular feeding and active pharyngeal filter feeding. The results demonstrate that an orientation with the mouth facing downstream of the current was optimal for drag and lift reduction. Moreover, they show that there was almost no flow to the mouth and associated marginal groove under simulations of passive feeding, whereas considerable flow towards the animal was observed for active feeding, which would have enhanced the transport of suspended particles to the mouth. This strongly suggests that cinctans were active pharyngeal filter feeders, like modern enteropneust hemichordates and urochordates, indicating that the ancestral deuterostome employed a similar feeding strategy. © 2015 The Author(s).

  18. Cadomian volcanosedimentary complexes across the Ediacaran-Cambrian transition of the Eastern Pyrenees, southwestern Europe (United States)

    Padel, Maxime; Álvaro, J. Javier; Casas, Josep Maria; Clausen, Sébastien; Poujol, Marc; Sánchez-García, Teresa


    The volcanism hosted by the Ediacaran-Terreneuvian Canaveilles Group of the Eastern Pyrenees displays two distinct geochemical affinities: (1) metabasites of the Nyer and Olette formations reflect the emplacement of a tholeiitic magmatism linked to extensional conditions, whereas (2) subsequent felsic and calc-alkaline magmatic rocks marking the top of the Olette Formation and forming the overlying Fabert and Finestrelles members represent Cadomian magmatic events. Based on U-Pb zircon dating constraints, palaeotopographic relationships linked to onlap geometries and distance from vent sources, three volcanosedimentary edifices can be distinguished, the so-called Tregurà (ca. 565-552 Ma), Cap de Creus (ca. 558 Ma) and Coll d'Ares (ca. 542-532 Ma) edifices. The top of their palaeoreliefs recorded locally the nucleation of centres of microbial carbonate productivity (Puig Sec Member) linked to synsedimentary tilting and karstification. Throughout West Gondwana, the presence of carbonate production across the Ediacaran-Cambrian transition is exclusively located in back-arc settings (Central-Iberian Zone) and areas far from the Cadomian subduction trench and devoid of significant terrigenous input, such as those reported in the Eastern Pyrenees and the neighbouring Montagne Noire.

  19. Experimental taphonomy and the anatomy and diversity of the earliest fossil vertebrates (Chengjiang Biota, Cambrian, China) (United States)

    Purnell, Mark; Gabbott, Sarah; Murdock, Duncan; Cong, Peiyun


    The oldest fossil vertebrates are from the Lower Cambrian Chengjiang biota of China, which contains four genera of fish-like, primitive vertebrates: Haikouichthys, Myllokunmingia, Zhongjianichthys and Zhongxiniscus. These fossils play key roles in calibrating molecular clocks and informing our view of the anatomy of animals close to the origin of vertebrates, potentially including transitional forms between vertebrates and their nearest relatives. Despite the evident importance of these fossils, the degree to which taphonomic processes have affected their anatomical completeness has not been investigated. For example, some or all might have been affected by stemward slippage - the pattern observed in experimental decay of non-biomineralised chordates in which preferential decay of synapomorphies and retention of plesiomorphic characters would cause fossil taxa to erroneously occupy more basal positions than they should. This hypothesis is based on experimental data derived from decay of non-biomineralised chordates under laboratory conditions. We have expanded this analysis to include a broader range of potentially significant environmental variables; we have also compared and combined the results of experiments from several taxa to identify general patterns of chordate decay. Examination of the Chengjiang vertebrates in the light of these results demonstrates that, contrary to some assertions, experimentally derived models of phylogenetic bias are applicable to fossils. Anatomical and phylogenetic interpretations of early vertebrates that do not take taphonomic biases into account risk overestimating diversity and the evolutionary significance of differences between fossil specimens.

  20. The hard parts of the Cambrian Explosion: a palaeobiological approach to testing the 'biomineralization toolkit' hypothesis (United States)

    Murdock, Duncan


    The Cambrian Explosion was the most dramatic event in the history of animal life on Earth, yet the processes underlying it are poorly understood not least the role of biomineralization in driving this fundamental evolutionary episode. One explanation for this event, based on observations on the developmental and molecular biology of modern organisms, is that all animals inherited a common 'toolkit' of genes, independently co-opted to similar tasks, including building skeletons. This initially imprecise 'toolkit' was subsequently honed by the acquisition of more and more complex gene regulatory networks. This predicts that animal skeletons, and by inference their organic frameworks, should exhibit a higher degree of morphological plasticity at their origin than later in their evolutionary history - a prediction that is virtually untested. Here I set out a new approach to testing this prediction, by quantifying the phenotypic variation displayed in fossil remains of some of the earliest animal skeletons, over multiple scales from microscopic variations in their component biominerals to how skeletons themselves are put together. This approach will provide direct evidence to test the importance of the genetic basis of the skeleton in the origin of the animals, making a significant contribution to our understanding of this crucial event in the history of life on Earth, including the evolution of our own ancestors.

  1. Diagenetic evolution of Cenozoic sandstones, Gulf of Mexico sedimentary basin (United States)

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


    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.

  2. Effects of burial depth on seed germination and seedling emergence of Mexican oaks: A glasshouse experiment

    Directory of Open Access Journals (Sweden)

    Flores-Cano J.


    Full Text Available Despite the interest in restoring oak forests in Mexico, very little is known about their regeneration ecology. We assessed the influence of acorn burial depth on seed germination and seedling emergence for eight Mexican oak species (Q. affinis, Q. castanea, Q. coccolobifolia, Q. laeta, Q. mexicana, Q. polymorpha, Q. tinkhamii and Q. viminea. We performed a glasshouse experiment in which acorns were buried at five soil depths (0, 2, 4, 6 and 8 cm. After four months, acorn germination and seedling emergence were recorded. Buried acorns showed higher germination and seedling emergence than unburied ones, but burial depth also influenced these responses. The optimum burial depth for seedling emergence of each species was 2, 4, 6 and 8 cm depth for four species (Q. castanea, Q. mexicana, Q. tinkhamii, and Q. viminea; 2 and 4 cm for Q. laeta; as well as 2, 4 and 8 cm for Q. coccolobifolia.

  3. High-precision Temporal Calibration of the Early Cambrian Biotic and Paleoenvironmental Records: New U-Pb Geochronology from Eastern Yunnan, China. (United States)

    Tsukui, K.; Ramezani, J.; Zhu, M.; Maloof, A. C.; Porter, S.; Moore, J.; Eddy, M. P.; Bowring, S. A.


    The Terreneuvian Epoch of the early Cambrian marks the global diversification of early animal life, as well as major perturbations to Earth's geochemical cycles. Understanding possible links between biotic evolution (e.g., emergence of skeletal animals) and the recognized changes in ocean chemistry requires a high fidelity chronostratigraphic framework for the early Cambrian records. One such chronostratigraphy was built by mapping local early Cambrian carbon isotope profiles onto a U-Pb age-calibrated marine carbonate δ13C record from Morocco, assuming global synchroneity of the observed δ13C trends. Here we present a direct test of this assumption using high-precision U-Pb geochronology (CA-ID-TIMS method) of ash beds from key lower Cambrian horizons throughout eastern Yunnan Province in South China. Preliminary age results from ash beds near the top of the Dengying Formation (Fm.) and the basal Daibu Member (Mb.) of the Zhujiaqing Fm. in multiple sections place the basal Cambrian negative δ13C excursion (BACE) in China at ca. 540.7-539.6 Ma. Our new U-Pb dates from the overlying Zhongyicun Mb. at the Meishucun and nearby sections improve significantly upon previous in situ U-Pb geochronology and constrain the onset of high-frequency δ13C oscillations in some sections to between 533.5 and 532.9 Ma. Most importantly, a new U-Pb date of ca. 526 Ma from the basal Shiyantou Fm. in the Xiaotan Section marks the termination of a >1 million year-long period of consistently positive (≥+4‰) δ13C values (ZHUCE) that is characteristic of many early Cambrian records worldwide. This date establishes a robust time correlation between ZHUCE in South China and its equivalent 5p excursion in Morocco and Siberia, and constrains the timing and duration of the largest positive δ13C anomalies in the Cambrian.

  4. New hydroxyproline radiocarbon dates from Sungir, Russia, confirm early Mid Upper Palaeolithic burials in Eurasia. (United States)

    Nalawade-Chavan, Shweta; McCullagh, James; Hedges, Robert


    Sungir (Russia) is a key Mid-Upper Palaeolithic site in Eurasia, containing several spectacular burials that disclose early evidence for complex burial rites in the form of a range of grave goods deposited along with the dead. Dating has been particularly challenging, with multiple radiocarbon dates ranging from 19,160±270 to 28,800±240 BP for burials that are believed to be closely similar in age. There are disparities in the radiocarbon dates of human bones, faunal remains and charcoal found on the floor of burials. Our approach has been to develop compound-specific methods using High Performance Liquid Chromatography (HPLC) to separate single amino acids, such as hydroxyproline, and thereby avoid the known human contamination on the bones themselves. Previously, we applied this technique to obtain radiocarbon dates of ∼30,000 BP for Sungir 2, Sungir 3 and a mammoth bone from the occupation levels of the site. The single amino acid radiocarbon dates were in good agreement with each other compared to all the dates previously reported, supporting their reliability. Here we report new hydroxyproline dates for two more human burials from the same site, Sungir 1 and Sungir 4. All five hydroxyproline dates reported are statistically indistinguishable and support an identical age for the group. The results suggest that compound-specific radiocarbon analysis should be considered seriously as the method of choice when precious archaeological remains are to be dated because they give a demonstrably contaminant-free radiocarbon age. The new ages are, together with the previously dated 'Red Lady of Paviland' human in the British Isles, the earliest for Mid Upper Palaeolithic burial behaviour in Eurasia, and point to the precocious appearance of this form of rite in Europe Russia.

  5. New hydroxyproline radiocarbon dates from Sungir, Russia, confirm early Mid Upper Palaeolithic burials in Eurasia.

    Directory of Open Access Journals (Sweden)

    Shweta Nalawade-Chavan

    Full Text Available Sungir (Russia is a key Mid-Upper Palaeolithic site in Eurasia, containing several spectacular burials that disclose early evidence for complex burial rites in the form of a range of grave goods deposited along with the dead. Dating has been particularly challenging, with multiple radiocarbon dates ranging from 19,160±270 to 28,800±240 BP for burials that are believed to be closely similar in age. There are disparities in the radiocarbon dates of human bones, faunal remains and charcoal found on the floor of burials. Our approach has been to develop compound-specific methods using High Performance Liquid Chromatography (HPLC to separate single amino acids, such as hydroxyproline, and thereby avoid the known human contamination on the bones themselves. Previously, we applied this technique to obtain radiocarbon dates of ∼30,000 BP for Sungir 2, Sungir 3 and a mammoth bone from the occupation levels of the site. The single amino acid radiocarbon dates were in good agreement with each other compared to all the dates previously reported, supporting their reliability. Here we report new hydroxyproline dates for two more human burials from the same site, Sungir 1 and Sungir 4. All five hydroxyproline dates reported are statistically indistinguishable and support an identical age for the group. The results suggest that compound-specific radiocarbon analysis should be considered seriously as the method of choice when precious archaeological remains are to be dated because they give a demonstrably contaminant-free radiocarbon age. The new ages are, together with the previously dated 'Red Lady of Paviland' human in the British Isles, the earliest for Mid Upper Palaeolithic burial behaviour in Eurasia, and point to the precocious appearance of this form of rite in Europe Russia.

  6. Phosphorus burial in the ocean over glacial-interglacial time scales

    Directory of Open Access Journals (Sweden)

    F. Tamburini


    Full Text Available The role of nutrients, such as phosphorus (P, and their impact on primary productivity and the fluctuations in atmospheric CO2 over glacial-interglacial periods are intensely debated. Suggestions as to the importance of P evolved from an earlier proposal that P actively participated in changing productivity rates and therefore climate change, to most recent ones that changes in the glacial ocean inventory of phosphorus were important but not influential if compared to other macronutrients, such as nitrate. Using new data coming from a selection of ODP sites, we analyzed the distribution of oceanic P sedimentary phases and calculate reactive P burial fluxes, and we show how P burial fluxes changed over the last glacial-interglacial period at these sites. Concentrations of reactive P are generally lower during glacial times, while mass accumulation rates (MAR of reactive P show higher variability. If we extrapolate for the analyzed sites, we may assume that in general glacial burial fluxes of reactive P are lower than those during interglacial periods by about 8%, because the lack of burial of reactive P on the glacial shelf reduced in size, was apparently not compensated by burial in other regions of the ocean. Using the calculated changes in P burial, we evaluate their possible impact on the phosphate inventory in the world oceans. Using a simple mathematical approach, we find that these changes alone could have increased the phosphate inventory of glacial ocean waters by 17–40% compared to interglacial stages. Variations in the distribution of sedimentary P phases at the investigated sites seem to indicate that at the onset of interglacial stages, shallower sites experienced an increase in reactive P concentrations, which seems to point to P-richer waters at glacial terminations. All these findings would support the Shelf-Nutrient Hypothesis, which assumes that during glacial low stands nutrients are transferred from shallow sites

  7. Electrokinetic desalination of sandstones for NaCl removal

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Christensen, Iben V.


    Salt induced decay is a serious threat to many historic stone and brick buildings and monuments. Further salt decay can be problematic in more recent buildings, as well, causing repeated plaster and paint peeling and increased hygroscopic moisture content. There is a need for development of relia......Salt induced decay is a serious threat to many historic stone and brick buildings and monuments. Further salt decay can be problematic in more recent buildings, as well, causing repeated plaster and paint peeling and increased hygroscopic moisture content. There is a need for development...... of reliable methods to remove the damaging salts in order to stop the decay. Electrokinetic desalination of fired clay bricks have previously shown efficient in laboratory scale and in the present work the method is tested for desalination of Cotta and Posta sandstones, which both have lower porosity than...... the bricks studied. The stones were contaminated with NaCl by submersion prior to the desalination experiments, where an electric DC field was applied to the stones from electrodes placed in clay poultice. Two poultice types were tested: calcareous clay used brick production and a mixture of kaolinite...

  8. Mineral changes in cement-sandstone matrices induced by biocementation

    Energy Technology Data Exchange (ETDEWEB)

    Verba, C. [National Energy Technology Lab. (NETL), Albany, OR (United States); Thurber, A. R. [Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Sciences; Alleau, Y. [Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Sciences; Koley, D. [Oregon State Univ., Corvallis, OR (United States). College of Science; Colwell, F. [Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Sciences; Torres, M. E. [Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Sciences


    Prevention of wellbore CO2 leakage is a critical component of any successful carbon capture, utilization, and storage program. Sporosarcina pasteurii is a bacterium that has demonstrated the potential ability to seal a compromised wellbore through the enzymatic precipitation of CaCO3. In this paper, we investigate the growth of S. pasteurii in a synthetic brine that mimics the Illinois Basin and on Mt. Simon sandstone encased in Class H Portland cement under high pressure and supercritical CO2 (PCO2) conditions. The bacterium grew optimum at 30 °C compared to 40 °C under ambient and high pressure (10 MPa) conditions; and growth was comparable in experiments at high PCO2. Sporosarcina pasteurii actively induced the biomineralization of CaCO3 polymorphs and MgCa(CO3)2 in both ambient and high pressure conditions as observed in electron microscopy. In contrast, abiotic (non-biological) samples exposed to CO2 resulted in the formation of surficial vaterite and calcite. Finally, the ability of S. pasteurii to grow under subsurface conditions may be a promising mechanism to enhance wellbore integrity.

  9. Outcrop analogue study of Permocarboniferous geothermal sandstone reservoir formations (northern Upper Rhine Graben, Germany): impact of mineral content, depositional environment and diagenesis on petrophysical properties (United States)

    Aretz, Achim; Bär, Kristian; Götz, Annette E.; Sass, Ingo


    oil and acidic waters led to the dissolution of haematite cements in the lower Permocarboniferous formations. During the Eocene, subsidence of the Upper Rhine Graben porosities and permeabilities of the sandstones of these formations were strongly reduced to 2.5 % and 3.2 × 10-18 m2. The second important influence on reservoir quality is the distinct depositional environment and its influence on early diagenetic processes. In early stage diagenesis, the best influence on reservoir properties exhibits a haematite cementation. It typically occurs in eolian sandstones of the Kreuznach Formation (Upper Permocarboniferous) and is characterized by grain covering haematite coatings, which are interpreted to inhibit cementation, compaction and illitization of pore space during burial. Eolian sandstones taken from outcrops and reservoir depths exhibit the highest porosities (16.4; 12.3 %) and permeabilities (2.0 × 10-15; 8.4 × 10-16 m2). A third important influence on reservoir quality is the general mineral composition and the quartz content which is the highest in the Kreuznach Formation with 73.8 %. Based on the integrated study of depositional environments and diagenetic processes, reservoir properties of the different Permocarboniferous formations within the northern Upper Rhine Graben and their changes with burial depth can be predicted with satisfactory accuracy. This leads to a better understanding of the reservoir quality and enables an appropriate well design for exploration and exploitation of these geothermal resources.

  10. Burial diagenesis of deep sea chalk as reflected in Biot's coefficient

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Alam, Mohammad Monzurul


    to limestone as burial increases and porosity decreases. The porosity decrease is accompanied by an increasing velocity to elastic waves, and consequently a decreasing Biot's coefficient, as estimated from velocity and density of core samples. When the effective burial stress is normalized to total horizontal....... In the ooze, we find that the natural compaction causes an increasing stress on grain contact area, indicating that the ooze particles become strongly strained. In the chalk section, contact cement is probably the reason why particles become less strained as porosity declines. In the limestone, stress...

  11. Burial diagenesis of deep sea chalk as reflected in Biot’s coefficient

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Alam, Mohammad Monzurul

    to limestone as burial increases and porosity decreases. The porosity decrease is accompanied by an increasing velocity to elastic waves, and consequently a decreasing Biot’s coefficient, as estimated from velocity and density of core samples. When the effective burial stress is normalized to total horizontal....... In the ooze, we find that the natural compaction causes an increasing stress on grain contact area, indicating that the ooze particles become strongly strained. In the chalk section, contact cement is probably the reason why particles become less strained as porosity declines. In the limestone, stress...

  12. Sampling and Analysis Instruction for Borehole Sampling at 118-B-1 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    W. S. Thompson


    The Washington Closure Hanford (WCH) Field Remediation Project has removed all of the disposed materials and contaminated soil from the 118-B-1 Burial Ground with the exception of tritium-contaminated soil that is believed to extend from the bottom of the present excavation to groundwater and is believed to contribute to tritium contamination observed at down-gradient monitoring Well 199-B8-6. This sampling and analysis instruction (SAI) provides the requirements for sample collection and laboratory analysis for characterization of the vertical distribution of tritium contamination in the vadose zone soil below the 118-B-1 Burial Ground remedial action excavation.

  13. Limits for the burial of the Department of Energy transuranic wastes

    Energy Technology Data Exchange (ETDEWEB)

    Healy, J.W.; Rodgers, J.C.


    Potential limits for the shallow earth burial of transuranic elements were examined by simplified models of the individual pathways to man. Pathways examined included transport to surface steams, transport to ground water, intrusion, and people living on the burial ground area after the wastes have surfaced. Limits are derived for each pathway and operational limits are suggested based upon a dose to the organ receiving the maximum dose rate of 0.5 rem/y after 70 years of exposure for the maximum exposed individual.

  14. Tillage energy savings from zone burial of shredded and whole cotton stalks

    Energy Technology Data Exchange (ETDEWEB)

    Carter, L.; Chesson, J.; Thacker, G.; Penner, V.


    Two prototypes of a stalk burial implement were tested for energy requirements at the University of California, Shafter Research Station. Both versions of the implement are designed to bury the cotton stalks in a concentrated Zone and reform the bed in the same location. To plow under shredded stalks, both versions of the implement required less energy than a conventional tillage systems typical of the San Joaquin Valley of California. Both stalk burial implements were also used to plow under whole cotton stalks. This offers additional energy savings by eliminating the stalk shredding operation.

  15. Compactional deformation bands in Wingate Sandstone; additional evidence of an impact origin for Upheaval Dome, Utah (United States)

    Okubo, Chris H.; Schultz, Richard A.


    Field and microstructural observations from Upheaval Dome, in Canyonlands National Park, Utah, show that inelastic strain of the Wingate Sandstone is localized along compactional deformation bands. These bands are tabular discontinuities (Jurassic) age for this impact.

  16. Local diversity versus geographical distribution of arthropods occuring in a sandstone rock labyrinth

    Czech Academy of Sciences Publication Activity Database

    Růžička, Vlastimil; Mlejnek, R.; Šmilauer, P.


    Roč. 58, č. 3 (2010), s. 533-544 ISSN 1505-2249 Institutional research plan: CEZ:AV0Z50070508 Keywords : sandstone * microclimate * paleorefugium Subject RIV: EH - Ecology, Behaviour Impact factor: 0.542, year: 2010

  17. Heavy mineral sorting in downwards injected Palaeocene sandstone, Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan Byskov


    Post-depositional remobilization and injection of sand are often seen in deep-water clastic systems and has been recently recognised as a significant modifier of deep-water sandstone geometry. Large-scale injectite complexes have been interpreted from borehole data in the Palaeocene Siri Canyon...... of depositional structures in deep-water sandstones, the distinction between "in situ" and injected or remobilised sandstones is often ambiguous. Large scale heavy mineral sorting (in 10 m thick units) is observed in several reservoir units in the Siri Canyon and has been interpreted to represent the depositional...... sorting. In this study we describe an example of effective shear-zone sorting of heavy minerals in a thin downward injected sandstone dyke which was encountered in one of the cores in the Cecilie Field, Siri Canyon. Differences in sorting pattern of heavy minerals are suggested as a tool for petrographic...

  18. Investigating the effect of unloading on artificial sandstone behaviour using the Discrete Element Method

    Directory of Open Access Journals (Sweden)

    Huang Yueqin


    Full Text Available The Discrete Element Method (DEM was used to simulate the mechanical behaviour of a reservoir sandstone. Triaxial tests were carried out using 3D-DEM to simulate the stress-strain behaviour of a sandstone with comparisons made between the numerical tests and the laboratory tests. The influence of isotropic unloading was investigated, which was found to have impacts on bond breakages and was successfully captured in the 3D shearing processes. It was found that bond breakages correlated strongly with the stress-strain behaviour of the sandstone affecting the peak strength. It was also found that unloading affected the bond breakages, which then changed the mechanical behaviour of sandstone. The tangent stiffnesses of simulated virgin and cored samples under different confining stresses were compared. From the tangent stiffnesses, gross yield envelopes and the yielding surfaces for unloaded samples and virgin samples were plotted and analysed in detail.

  19. CO2 Storage Potential of the Eocene Tay Sandstone, Central North Sea, UK (United States)

    Gent, Christopher; Williams, John


    Carbon Capture and Storage (CCS) is crucial for low-carbon industry, climate mitigation and a sustainable energy future. The offshore capacity of the UK is substantial and has been estimated at 78 Gt of CO2 in saline aquifers and hydrocarbon fields. The early-mid Eocene Tay Sandstone Member of the Central North Sea (CNS) is a submarine-fan system and potential storage reservoir with a theoretical capacity of 123 Mt of CO2. The Tay Sandstone comprises of 4 sequences, amalgamating into a fan complex 125km long and 40 km at a minimum of 1500 m depth striking NW-SE, hosting several hydrocarbon fields including Gannett A, B, D and Pict. In order to better understand the storage potential and characteristics, the Tay Sandstone over Quadrant 21 has been interpreted using log correlation and 3D seismic. Understanding the internal and external geometry of the sandstone as well as the lateral extent of the unit is essential when considering CO2 vertical and horizontal fluid flow pathways and storage security. 3D seismic mapping of a clear mounded feature has revealed the youngest sequence of the Tay complex; a homogenous sand-rich channel 12 km long, 1.5 km wide and on average 100 m thick. The sandstone has porosity >35%, permeability >5 D and a net to gross of 0.8, giving a total pore volume of 927x106 m3. The remaining three sequences are a series of stacked channels and interbedded mudstones which are more quiescent on the seismic, however, well logs indicate each subsequent sequence reduce in net to gross with age as mud has a greater influence in the early fan system. Nevertheless, the sandstone properties remain relatively consistent and are far more laterally extensive than the youngest sequence. The Tay Sandstone spatially overlaps several other potential storage sites including the older Tertiary sandstones of the Cromarty, Forties and Mey Members and deeper Jurassic reservoirs. This favours the Tay Sandstone to be considered in a secondary or multiple stacked

  20. Middle Ordovician brachiopods from the Stairway Sandstone, Amadeus Basin, central Australia

    DEFF Research Database (Denmark)

    Jakobsen, Kristian Grube; Brock, Glenn A.; Nielsen, Arne Thorshøj


    Middle Ordovician brachiopod faunas from the Amadeus Basin, central Australia are poorly known. The Darriwilian Stairway Sandstone was sampled stratigraphically for macrofossils in order to provide new information on marine benthic diversity in this clastic-dominated, shallow-water palaeoenvironm......Middle Ordovician brachiopod faunas from the Amadeus Basin, central Australia are poorly known. The Darriwilian Stairway Sandstone was sampled stratigraphically for macrofossils in order to provide new information on marine benthic diversity in this clastic-dominated, shallow...

  1. Sandstone Provenance of the De Geerdalen Formation, Svalbard - Emphasis on Petrography and Chromium Spinel Compositions


    Harstad, Trond Svånå


    Detrital chromium spinel mineral-chemical analyses, in combination with sandstone petrography, were conducted on samples from the Upper Triassic De Geerdalen Formation from several locations on Svalbard, in order to interpret sandstone provenance. Petrographic identification of detrital minerals and lithic fragments was used to identify source rock lithology. The accessory mineral chromium spinel was used as a petrogenetic marker to distinguish tectonic setting of mafic and ultra- mafic sourc...

  2. The Gravettian burial known as the Prince (‘Il Principe’) : new evidence for his age and diet.


    Pettitt, P B; Richards, M. P.; Maggi, R.; Formicola, V.


    The famous upper Palaeolithic (Gravettian) burial with shell ornaments known as "Il Principe" was discovered in Italy sixty years ago. Here the authors present recent scientific research on his skeleton, leading to new assessments of the date of the burial and indications of diet.

  3. 77 FR 64361 - Report on Waste Burial Charges: Changes in Decommissioning Waste Disposal Costs at Low-Level... (United States)


    ... COMMISSION Report on Waste Burial Charges: Changes in Decommissioning Waste Disposal Costs at Low-Level Waste...: Changes in Decommissioning Waste Disposal Costs at Low-Level Waste Burial Facilities,'' in the Federal... published in November 2010. NUREG-1307, Revision 15, also incorporates changes resulting from a reassessment...

  4. Effects of fragment traits, burial orientation and nutrient supply on survival and growth in Populus deltoides × P. simonii. (United States)

    Zhang, Ping; Su, Zhi-Qin; Xu, Lie; Shi, Xue-Ping; Du, Ke-Bing; Zheng, Bo; Wang, Yong-Jian


    Clonal propagations of shoot or root fragments play pivotal roles in adaptation of clonal trees to environmental heterogeneity, i.e. soil nutrient heterogeneity and burials after disturbance. However, little is known about whether burial orientation and nutrient supply can alter the effects of fragment traits in Populus. Shoot and root fragments of Populus deltoides × P. simonii were subjected to burials in two different fragment diameters (0.5 and 2.0 cm), two fragment lengths (5 and 15 cm) and three burial orientations (horizontal, upward and downward). For the shoot fragments, survival and growth were significantly higher in the larger pieces (either in length or diameter) and the horizontal/upward burial position. On the contrary, the effect of burial position was reversed for the root fragments. Shoot/root fragments of 15 cm in length in horizontal burial position were then subjected to two different fragment diameters (0.5 and 2.0 cm) and four types of nutrient supplies (without nutrient, low frequency, high frequency and patchy). Growth of shoot fragments of 2.0 cm in diameter significantly increased in high frequency and patchy nutrient supplies than that of without nutrient treatment. These results suggest that burial orientation and nutrient supply could be employed in clonal propagations of cuttings, afforestation or regeneration in Populus.

  5. Phosphorus burial in sediments of the sulfidic deep Black Sea : Key roles for adsorption by calcium carbonate and apatite authigenesis

    NARCIS (Netherlands)

    Kraal, Peter; Dijkstra, Nikki; Behrends, Thilo; Slomp, Caroline P.


    Abstract Sedimentary burial of the essential nutrient phosphorus (P) under anoxic and sulfidic conditions is incompletely understood. Here, we use chemical and micro-scale spectroscopic methods to characterize sedimentary P burial along a water column redox transect (six stations, 78–2107 m water

  6. 78 FR 76712 - Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (United States)


    ... AFFAIRS Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (VA) to provide a monetary allowance towards the private purchase of an outer burial receptacle for use in a VA national cemetery. Under VA regulation (38 CFR 38.629), the allowance is equal to the...

  7. 75 FR 67454 - Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (United States)


    ... AFFAIRS Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (VA) to provide a monetary allowance towards the private purchase of an outer burial receptacle for use in a VA national cemetery. Under VA regulation (38 CFR 38.629), the allowance is equal to the...

  8. 77 FR 74743 - Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (United States)


    ... AFFAIRS Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (VA) to provide a monetary allowance towards the private purchase of an outer burial receptacle for use in a VA national cemetery. Under VA regulation (38 CFR 38.629), the allowance is equal to the...

  9. 76 FR 77327 - Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (United States)


    ... AFFAIRS Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (VA) to provide a monetary allowance towards the private purchase of an outer burial receptacle for use in a VA national cemetery. Under VA regulation (38 CFR 38.629), the allowance is equal to the...

  10. 75 FR 1454 - Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (United States)


    ... AFFAIRS Allowance for Private Purchase of an Outer Burial Receptacle in Lieu of a Government-Furnished... (VA) to provide a monetary allowance towards the private purchase of an outer burial receptacle for use in a VA national cemetery. Under VA regulation (38 CFR 38.629), the allowance is equal to the...

  11. Analyzing the Sand-fixing Effect of Feldspathic Sandstone from the Texture Characteristics (United States)

    Zhang, lu; Ban, Jichang


    The purpose of this research was aimed to study the sand fixing effect of feldspathic sandstone in Mu Us Sandy Land, to provide a scienticic basis for desertification control, soil and water conservation and development of farming there. Methods of mixing feldspathic sandstone and aeolian sandy soil according to 1: 0, 1: 1, 1: 2, 1: 5, and 0: 1 mass ratioes, the graded composition and characteristics were studied with laser particle size analyzer. The result showed that these features of sand-based, loosely structured, easy to wind erosion of aeolian sandy soil were changed before feldspathic sandstone and aeolian sandy soil compounding. The m(F): m(S) was 1: 5(Cu was 54.71 and Cc was 2.54) or when m(F): m(S) was 1: 2(Cu was 76.21, Cc was 1.12). The conclusion is that feldspathic sandstone has sand-fixing effect in texture characteristics, which heightens with feldspathic sandstone mass increasing, and when the mass ratio of feldspathic sandstone: aeolian sandy soil is 1: 2 or 1: 5 which compound better.

  12. Effects of Thermal Treatment on the Dynamic Mechanical Properties of Coal Measures Sandstone (United States)

    Li, Ming; Mao, Xianbiao; Cao, Lili; Pu, Hai; Mao, Rongrong; Lu, Aihong


    Many projects such as the underground gasification of coal seams and coal-bed methane mining (exploitation) widely involve the dynamic problems of coal measures sandstone achieved via thermal treatment. This study examines the dynamic mechanical properties of coal measures sandstone after thermal treatment by means of an MTS653 high-temperature furnace and Split Hopkinson pressure bar test system. Experimental results indicate that 500 °C is a transition point for the dynamic mechanical parameters of coal measures sandstone. The dynamic elastic modulus and peak strength increase linearly from 25 to 500 °C while the dynamic peak strain decreases linearly over the same temperature range. The dynamic elastic modulus and peak strength drop quickly from 500 to 800 °C, with a significant increase in the dynamic peak strain over the same temperature range. The rock mechanics are closely linked to material composition and mesoscopic structure. Analysis by X-ray diffraction and scanning electron microscopy indicate that the molecules inside the sandstone increase in density due to the thermal expansion of the material particles, which effectively improves the deformation resistance and carrying capacity of the sandstone and reduces the likelihood of axial deformation. With heat treatment that exceeds 500 °C, the dynamic mechanical properties rapidly weaken due to the decomposition of kaolinite; additionally, hot cracking of the mineral particles within the materials arises from coal sandstone internal porosity, and other defects gradually appear.

  13. Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada (United States)

    Nastev, Miroslav; Morin, R.; Godin, Rejean; Rouleau, Alain


    A hydrogeological study was conducted in Potsdam sandstones on the international border between Canada (Quebec) and the USA (New York). Two sandstone formations, arkose and conglomerate (base) and well-cemented quartz arenite (upper), underlie the study area and form the major regional aquifer unit. Glacial till, littoral sand and gravel, and marine silt and clay discontinuously overlie the aquifer. In both sandstone formations, sub-horizontal bedding planes are ubiquitous and display significant hydraulic conductivities that are orders of magnitude more permeable than the intact rock matrix. Aquifer tests demonstrate that the two formations have similar bulk hydrologic properties, with average hydraulic conductivities ranging from 2 ?? 10-5 to 4 ?? 10-5 m/s. However, due to their different lithologic and structural characteristics, these two sandstones impose rather different controls on groundwater flow patterns in the study area. Flow is sustained through two types of fracture networks: sub-horizontal, laterally extensive fractures in the basal sandstone, where hydraulic connectivity is very good horizontally but very poor vertically and each of the water-bearing bedding planes can be considered as a separate planar two-dimensional aquifer unit; and the more fractured and vertically jointed system found in the upper sandstone that promotes a more dispersed, three-dimensional movement of groundwater. ?? Springer-Verlag 2007.

  14. Stable isotope (δ13Cker, δ13Ccarb, δ18Ocarb distribution along a Cambrian outcrop section in the eastern Tarim Basin, NW China and its geochemical significance

    Directory of Open Access Journals (Sweden)

    Hu Liu


    Full Text Available This study investigated the geochemical features of the lower Paleozoic strata of Yaerdang Mountain outcrop along with the core samples from well TD2∈ in the eastern Tarim Basin, NW China. The total organic carbon abundance, hydrocarbon-generating precursor biospecies, and stable isotope ratios of organics and carbonate (δ13Cker, δ13Ccarb and δ18Ocarb were comprehensively studied for their possible correlative constraints during sedimentary evolution. The results revealed that the δ13Cker (VPDB of Cambrian kerogens along the outcrop section varied from −34.6‰ to −28.4‰, indicating an increasing tendency from the lower Cambrian to the upper Cambrian. This was on the whole accompanied by the variation in the δ13Ccarb and δ18Ocarb along the profile, which might be associated with the changes in the sea level and also in the compositional variation of benthic and planktonic biomass. The large variation in the stable carbon isotope ratios up to 6‰ along the outcrop section reflected the heterogeneity of the Cambrian source rocks from the eastern Tarim Basin. Hence, the 13C-enriched crude oils from well TD2∈ might have been derived from a localized stratum of Cambrian source rocks. The results from this study showed the possibility of multiple source kitchens in the Cambrian–lower Ordovician portion of Tarim Basin.

  15. Population Structure, Life Strategies and Systematics of Phosphatocope Ostracods from the Middle Cambrian of Bornholm

    Directory of Open Access Journals (Sweden)

    I. Hinz-Schallreuter


    Full Text Available She Middle Cambrian Borregård Member of Bornholm which is the stratigraphical equivalent to the Baltoscandian Exsulans Limestone yielded a rich and comparatively diverse ostracod fauna in its upper part. It comprises eight species out of four genera. They belong to three known subfamilies that are redefined on the basis of special characters of the contact margin. An ontogenetic character unknown from typical ostracods is documented in several species: during early ontogeny the gestalt (l:h ratio develops constantly in becoming increasingly longer until the so-called ontogenetical turning point (OTP from which the direction of growth focusses on carapace height. This phenomenon may be explained by changes in body morphology. The Borregård association represents an ecologic community type differing from other yet recorded Middle Cambrian communities in the Baltoscandic region. Apart from Vestrogothia longispinosa which is a common faunal element in Baltoscandian ostracod faunas, the yet recorded species of Bidimorpha are unknown from other Baltoscandian occurrences. Vice versa, the known species of Bidimorpha described from Swedish occurrences have not been recognized in the rich Borregård community. Similarly, Falites insula and Hesslandona abdominalis may be of local significance, too, but the respective records from contemporaneous Swedish localities are insufficient in this respect, yet. Due to specific morphological adaptations, the four genera are assumed to represent different benthic life strategies. New taxa are: Bidimorpha arator n. sp., Bidimorpha labiator n. sp., Bidimorpha sexspinosa n. sp., Falites insula n. sp., Hesslandona abdominalis n. sp., Vestrogothia herrigi n. sp. and Vestrogothia minilaterospinata n. sp. Aus dem mittelkambrischen Borregård Member von Bornholm, einem zeitlichen Äquivalent des baltoskandischen Exsulanskalkes, wurde eine reiche und vergleichsweise diverse Ostrakodenfauna gewonnen. Sie umfaßt 8 Arten aus

  16. Integrated chronostratigraphy of Proterozoic-Cambrian boundary beds in the western Anabar region, northern Siberia (United States)

    Kaufman, A. J.; Knoll, A. H.; Semikhatov, M. A.; Grotzinger, J. P.; Jacobsen, S. B.; Adams, W.


    Carbonate-rich sedimentary rocks of the western Anabar region, northern Siberia, preserve an exceptional record of evolutionary and biogeochemical events near the Proterozoic/Cambrian boundary. Sedimentologically, the boundary succession can be divided into three sequences representing successive episodes of late transgressive to early highstand deposition; four parasequences are recognized in the sequence corresponding lithostratigraphically to the Manykal Formation. Small shelly fossils are abundant and include many taxa that also occur in standard sections of southeastern Siberia. Despite this coincidence of faunal elements, biostratigraphic correlations between the two regions have been controversial because numerous species that first appear at or immediately above the basal Tommotian boundary in southeastern sections have first appearances scattered through more than thirty metres of section in the western Anabar. Carbon- and Sr-isotopic data on petrographically and geochemically screened samples collected at one- to two-metre intervals in a section along the Kotuikan River, favour correlation of the Staraya Reckha Formation and most of the overlying Manykai Formation with sub-Tommotian carbonates in southeastern Siberia. In contrast, isotopic data suggest that the uppermost Manykai Formation and the basal 26 m of the unconformably overlying Medvezhya Formation may have no equivalent in the southeast; they appear to provide a sedimentary and palaeontological record of an evolutionarily significant time interval represented in southeastern Siberia only by the sub-Tommotian unconformity. Correlations with radiometrically dated horizons in the Olenek and Kharaulakh regions of northern Siberia suggest that this interval lasted approximately three to six million years, during which essentially all 'basal Tommotian' small shelly fossils evolved.

  17. Original molluscan radula: comparisons among Aplacophora, Polyplacophora, Gastropoda, and the Cambrian fossil Wiwaxia corrugata. (United States)

    Scheltema, Amélie H; Kerth, Klaus; Kuzirian, Alan M


    As the original molluscan radula is not known from direct observation, we consider what the form of the original radula may have been from evidence provided by neomenioid Aplacophora (Solenogastres), Gastropoda, Polyplacophora, and the Cambrian fossil Wiwaxia corrugata (Matthews). Conclusions are based on direct observation of radula morphology and its accessory structures (salivary gland ducts, radular sac, anteroventral radular pocket) in 25 species and 16 genera of Aplacophora; radula morphogenesis in Aplacophora; earliest tooth formation in Gastropoda (14 species among Prosobranchia, Opisthobranchia, and Pulmonata); earliest tooth formation in four species of Polyplacophora; and the morphology of the feeding apparatus in W. corrugata. The existence of a true radula membrane and of membranoblasts and odontoblasts in neomenioids indicates that morphogenesis of the aplacophoran radula is homologous to that in other radulate Mollusca. We conclude from p redness of salivary gland ducts, a divided radular sac, and a pair of anteroventral pockets that the plesiomorphic state in neomenioids is bipartite, formed of denticulate bars that are distichous (two teeth per row) on a partially divided or fused radula membrane with the largest denticles lateral, as occurs in the genus Helicoradomenia. The tooth morphology in Helicoradomenia is similar to the feeding apparatus in W. corrugata. We show that distichy also occurs during early development in several species of gastropods and polyplacophorans. Through the rejection of the null hypothesis that the earliest radula was unipartite and had no radula membrane, we conclude that the original molluscan radula was similar to the radula found in Helicoradomena species. Copyright 2003 Wiley-Liss, Inc.

  18. Cambrian suspension-feeding lobopodians and the early radiation of panarthropods. (United States)

    Caron, Jean-Bernard; Aria, Cédric


    Arthropoda, Tardigrada and Onychophora evolved from lobopodians, a paraphyletic group of disparate Palaeozoic vermiform animals with soft legs. Although the morphological diversity that this group encompasses likely illustrates the importance of niche diversification in the early radiation of panarthropods, the ecology of lobopodians remains poorly characterized. Here we describe a new luolishaniid taxon from the middle Cambrian Burgess Shale (Walcott Quarry) in British Columbia, Canada, whose specialized morphology epitomizes the suspension-feeding ecology of this clade, and is convergent with some modern marine animals, such as caprellid crustaceans. This species possesses two long pairs and four shorter pairs of elongate spinose lobopods at the front, each bearing two slender claws, and three pairs of stout lobopods bearing single, strong, hook-like anterior-facing claws at the back. The trunk is remarkably bare, widening rearwards, and, at the front, extends beyond the first pair of lobopods into a small "head" bearing a pair of visual organs and a short proboscis with numerous teeth. Based on a critical reappraisal of character coding in lobopodians and using Bayesian and parsimony-based tree searches, two alternative scenarios for early panarthropod evolution are retrieved. In both cases, hallucigeniids and luolishaniids are found to be extinct radiative stem group panarthropods, in contrast to previous analyses supporting a position of hallucigeniids as part of total-group Onychophora. Our Bayesian topology finds luolishaniids and hallucigeniids to form two successive clades at the base of Panarthropoda. Disparity analyses suggest that luolishaniids, hallucigeniids and total-group Onychophora each occupy a distinct region of morphospace. Hallucigeniids and luolishaniids were comparably diverse and successful, representing two major lobopodian clades in the early Palaeozoic, and both evolved body plans adapted to different forms of suspension feeding. A

  19. Paleoecology and paleoceanography of the Athel silicilyte, Ediacaran-Cambrian boundary, Sultanate of Oman. (United States)

    Stolper, D A; Love, G D; Bates, S; Lyons, T W; Young, E; Sessions, A L; Grotzinger, J P


    The Athel silicilyte is an enigmatic, hundreds of meters thick, finely laminated quartz deposit, in which silica precipitated in deep water (>~100-200 m) at the Ediacaran-Cambrian boundary in the South Oman Salt Basin. In contrast, Meso-Neoproterozoic sinks for marine silica were dominantly restricted to peritidal settings. The silicilyte is known to contain sterane biomarkers for demosponges, which today are benthic, obligately aerobic organisms. However, the basin has previously been described as permanently sulfidic and time-equivalent shallow-water carbonate platform and evaporitic facies lack silica. The Athel silicilyte thus represents a unique and poorly understood depositional system with implications for late Ediacaran marine chemistry and paleoecology. To address these issues, we made petrographic observations, analyzed biomarkers in the solvent-extractable bitumen, and measured whole-rock iron speciation and oxygen and silicon isotopes. These data indicate that the silicilyte is a distinct rock type both in its sedimentology and geochemistry and in the original biology present as compared to other facies from the same time period in Oman. The depositional environment of the silicilyte, as compared to the bounding shales, appears to have been more reducing at depth in sediments and possibly bottom waters with a significantly different biological community contributing to the preserved biomarkers. We propose a conceptual model for this system in which deeper, nutrient-rich waters mixed with surface seawater via episodic mixing, which stimulated primary production. The silica nucleated on this organic matter and then sank to the seafloor, forming the silicilyte in a sediment-starved system. We propose that the silicilyte may represent a type of environment that existed elsewhere during the Neoproterozoic. These environments may have represented an important locus for silica removal from the oceans. © 2017 John Wiley & Sons Ltd.

  20. The evolutionary and genetic origins of consciousness in the Cambrian Period over 500 million years ago

    Directory of Open Access Journals (Sweden)

    Todd E Feinberg


    Full Text Available Vertebrates evolved in the Cambrian Period before 520 million years ago, but we do not know when or how consciousness arose in the history of the vertebrate brain. Here we propose multiple levels of isomorphic or somatotopic neural representations as an objective marker for sensory consciousness. All extant vertebrates have these, so we deduce that consciousness extends back to the group’s origin. The first conscious sense may have been vision. Then vision, coupled with additional sensory systems derived from ectodermal placodes and neural crest, transformed primitive reflexive systems into image forming brains that map and perceive the external world and the body’s interior. We posit that the minimum requirement for sensory consciousness and qualia is a brain including a forebrain (but not necessarily a developed cerebral cortex/pallium, midbrain and hindbrain. This brain must also have 1 hierarchical systems of intercommunicating, isomorphically organized, processing nuclei that extensively integrate the different senses into representations that emerge in upper levels of the neural hierarchy; and 2 a widespread reticular formation that integrates the sensory inputs and contributes to attention, awareness, and neural synchronization. We propose a two-step evolutionary history, in which the optic tectum was the original center of multi-sensory conscious perception (as in fish and amphibians: step 1, followed by a gradual shift of this center to the dorsal pallium or its cerebral cortex (in mammals, reptiles, birds: step 2. We address objections to the hypothesis and call for more studies of fish and amphibians. In our view, the lamprey has all the neural requisites and is likely the simplest extant vertebrate with sensory consciousness and qualia. Genes that pattern the proposed elements of consciousness (isomorphism, neural crest, placodes have been identified in all vertebrates. Thus, consciousness is in the genes, some of which are

  1. The influence of clay minerals on acoustic properties of sandstones

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Olav


    This thesis aims to provide better understanding of the relationship between the acoustic properties and the petrophysical/mineralogical properties in sand-prone rock. It emphasizes the influence of clay minerals. The author develops a method to deposit clay minerals/mineral aggregates in pore space of a rigid rock framework. Kaolinite aggregates were flushed into porous permeable Bentheimer sandstone to evaluate the effect of pore filling minerals on porosity, permeability and acoustic properties. The compressional velocity was hardly affected by the clay content and it was found that the effect of minor quantities of pore filling minerals may be acoustically modelled as an ideal suspension, where the pore fluid bulk modulus is modified by the bulk modulus of the clay minerals. The influence of clays on acoustic velocities in petroleum reservoir rocks was investigated through ultrasonic measurements of compressional- and shear-waves on core material from reservoir and non-reservoir units on the Norwegian Continental Shelf. The measured velocities decrease as the porosity increases, but are not strongly dependent on the clay content. The measured velocities are less dependent on the petrophysical and lithological properties than indicated by previous authors and published mathematical models, and stiffness reduction factors are introduced in two of the models to better match the data. Velocities are estimated along the wellbores based on non-sonic well logs and reflect well the actual sonic log well measurements. In some wells the compressional velocity cannot be modelled correctly by the models suggested. Very high compressional wave anisotropy was measured in the dry samples at atmospheric conditions. As the samples were saturated, the anisotropy was reduced to a maximum of about 30% and decreases further upon pressurization. Reservoir rocks retrieved from 2500 m are more stress dependent than those retrieved from less than 200 m depth. 168 refs., 117 figs., 24

  2. Mesopotamian ceramics from the burial mounds of Bahrain, c.2250–1750 BC

    DEFF Research Database (Denmark)

    Laursen, Steffen


    Among the ceramic vessels recovered from the burial mounds of Bahrain, a small percentage represents Mesopotamian imports or local emulations of such. In this paper two overall horizons are distinguished in these Mesopotamian ceramics. These are significant because both coincide with major stages...

  3. Unique burial practice by ancient cavemen of the Hoa Binh civilization in Vietnam. (United States)

    Cuong, Nguyen Lan


    The discovery of a female skeleton is reported, which can be ascribed to the Hoa Binh civilization, existing about 10,000 years before now. The most remarkable fact concerning this finding is the existence of seashells (Cyprea arabica), which were found in the eye sockets. The reasons for this in Southeast Asia so far unique burial practice are discussed.

  4. Lithic Residue Survival and Characterisation at Star Carr: a burial experiment

    Directory of Open Access Journals (Sweden)

    Shannon Croft


    Full Text Available A modern burial experiment was devised to test microscopic residue survival in acidic peat and slightly acidic clay soils at the Early Mesolithic site of Star Carr (North Yorkshire, UK, and at nearby control location. The experiment addresses concerns regarding the applicability of residue analysis in varied burial environments, and particularly in highly acidic archaeological conditions. Flint flakes (n= 78, including blank controls were used on twelve plant, animal, and mineral materials to create residues and then buried. The residues were examined 1 month and 11 months after burial. An unburied reference collection containing the same twelve residue types in a fresh state was compared to the buried residues to assess diagenesis. The residue types that survived across all burial conditions and time intervals were: softwood tissue, tree resin, bird feathers, squirrel hair, and red ochre. During microscopic analysis, it became clear that many residues lack diagnostic traits, and thus an assessment of the extent to which each residue can be identified was conducted. The degree to which residues were able to be identified was further investigated with a variable pressure scanning electron microscope (SEM. SEM images of the reference residues were compared to the reflected VLM micrographs of the same residues, which improved characterisation in some cases. Residues were grouped into three categories (diagnostic, distinctive, and non-distinctive within a visual characterisation guide. Our in situ microscopic analyses indicated that few residue types have diagnostic traits that allow them to be identified unambiguously, and thus further characterisation techniques are often required.

  5. A unique human-fox burial from a pre-Natufian cemetery in the Levant (Jordan.

    Directory of Open Access Journals (Sweden)

    Lisa A Maher

    Full Text Available New human burials from northern Jordan provide important insights into the appearance of cemeteries and the nature of human-animal relationships within mortuary contexts during the Epipalaeolithic period (c. 23,000-11,600 cal BP in the Levant, reinforcing a socio-ideological relationship that goes beyond predator-prey. Previous work suggests that archaeological features indicative of social complexity occur suddenly during the latest Epipalaeolithic phase, the Natufian (c. 14,500-11,600 cal BP. These features include sedentism, cemeteries, architecture, food production, including animal domestication, and burials with elaborate mortuary treatments. Our findings from the pre-Natufian (Middle Epipalaeolithic cemetery of 'Uyun al-Hammam demonstrate that joint human-animal mortuary practices appear earlier in the Epipalaeolithic. We describe the earliest human-fox burial in the Near East, where the remains of dogs have been found associated with human burials at a number of Natufian sites. This is the first time that a fox has been documented in association with human interments pre-dating the Natufian and with a particular suite of grave goods. Analysis of the human and animal bones and their associated artefacts provides critical data on the nature and timing of these newly-developing relationships between people and animals prior to the appearance of domesticated dogs in the Natufian.

  6. Cleanup Verification Package for the 118-B-6, 108-B Solid Waste Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    M. L. Proctor


    This cleanup verification package documents completion of remedial action for the 118-B-6, 108-B Solid Waste Burial Ground. The 118-B-6 site consisted of 2 concrete pipes buried vertically in the ground and capped by a concrete pad with steel lids. The site was used for the disposal of wastes from the "metal line" of the P-10 Tritium Separation Project.

  7. Compositional variation in Roman colourless glass objects from the bocholtz burial (the Netherlands)

    NARCIS (Netherlands)

    Huisman, D.J.; Groot, T. de; Pols, S.; Os, B.J.H. van; Degryse, P.


    We investigated the major and trace element composition and Pb and Sr isotope characteristics of a series of about 20 colourless glass objects from a single high-status Roman burial from the Netherlands (Bocholtz). The major elements show a relatively homogeneous group, with one outlier. This is

  8. Preliminary fire hazard analysis for the PUTDR and TRU trenches in the Solid Waste Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    Gaschott, L.J.


    This document represents the Preliminary Fire Hazards Analysis for the Pilot Unvented TRU Drum Retrieval effort and for the Transuranic drum trenches in the low level burial grounds. The FHA was developed in accordance with DOE Order 5480.7A to address major hazards inherent in the facility.

  9. 38 CFR 3.1603 - Authority for burial of certain unclaimed bodies. (United States)


    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Authority for burial of... the body of a deceased veteran is unclaimed, there being no relatives or friends to claim the body... accompanied by a statement showing what efforts were made to locate relatives or friends. The question of...

  10. Geologic Descriptions for the Solid-Waste Low Level Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    Bjornstad, Bruce N.; Lanigan, David C.


    This document provides the stratigraphic framework and six hydrogeologic cross sections and interpretations for the solid-waste Low Level Burial Grounds on the Hanford Site. Four of the new cross sections are located in the 200 West Area while the other two are located within the 200 East Area. The cross sections display sediments of the vadose zone and uppermost unconfined aquifer.

  11. Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, A.; Pitts, M. [Pajarito Scientific Corporation, 2976 Rodeo Park Drive East, Santa Fe, NM 87505 (United States); Ludowise, J.D.; Valentinelli, P. [Washington Closure Hanford, 2620 Fermi Ave., Richland, WA 99354 (United States); Grando, C.J. [ELR Consulting, Inc., 15247 Wilbur Rd., La Conner, WA 98257 (United States); Haggard, D.L. [WorleyParsons Polestar, 601 Williams Blvd., Richland, WA 99354 (United States)


    The Hanford burial grounds contains a broad spectrum of low activity radioactive wastes, transuranic (TRU) wastes, and hazardous wastes including fission products, byproduct material (thorium and uranium), plutonium and laboratory chemicals. A passive neutron non-destructive assay technique has been developed for characterization of shielded concreted drums exhumed from the burial grounds. This method facilitates the separation of low activity radiological waste containers from TRU waste containers exhumed from the burial grounds. Two identical total neutron counting systems have been deployed, each consisting of He-3 detectors surrounded by a polyethylene moderator. The counts are processed through a statistical filter that removes outliers in order to suppress cosmic spallation events and electronic noise. Upon completion of processing, a 'GO / NO GO' signal is provided to the operator based on a threshold level equivalent to 0.5 grams of weapons grade plutonium in the container being evaluated. This approach allows instantaneous decisions to be made on how to proceed with the waste. The counting systems have been set up using initial on-site measurements (neutron emitting standards loaded into surrogate waste containers) combined with Monte Carlo modeling techniques. The benefit of this approach is to allow the systems to extend their measurement ranges, in terms of applicable matrix types and container sizes, with minimal interruption to the operations at the burial grounds. (authors)

  12. Metal-touching tools from ancient graves: The case of a Roman period royal burial

    Czech Academy of Sciences Publication Activity Database

    Ježek, Martin; Holub, Milan; Zavřel, Jan


    Roč. 18, April (2018), s. 333-342 ISSN 2352-409X R&D Projects: GA ČR(CZ) GA16-22207S Institutional support: RVO:67985912 Keywords : Roman period * elite * burial * touchstone * cinnabar * nickel * speiss Subject RIV: AC - Archeology, Anthropology, Ethnology

  13. Mixed Waste Management Facility (MWMF) Old Burial Ground (OBG) source control technology and inventory study

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.P.; Rehder, T.E.; Kanzleiter, J.P.


    This report has been developed to support information needs for wastes buried in the Burial Ground Complex. Information discussed is presented in a total of four individual attachments. The general focus of this report is to collect information on estimated source inventories, leaching studies, source control technologies, and to provide information on modeling parameters and associated data deficiencies.

  14. The Sociological Essence of Music in Burial: An Analysis of Akwa ...

    African Journals Online (AJOL)

    Music in traditional African setting is the soul which is ultimately concerned with various customs and religious practices. The African is born, fortified, initiated and buried with music. Music is a powerful part in African burials; it goes a long way to expose the deeds of deceased when he/she was alive. In some cultures, death ...


    Energy Technology Data Exchange (ETDEWEB)

    David A. Lopez


    Evaluation of the Lower Cretaceous Greybull Sandstone on the Crow Indian Reservation for potential stratigraphic traps in the valley-fill sandstone was the focus of this project. The Crow Reservation area, located in south-central Montana, is part of the Rocky Mountain Foreland structural province, which is characterized by Laramide uplifts and intervening structural basins. The Pryor and Bighorn mountains, like other foreland uplifts, are characterized by asymmetrical folds associated with basement-involved reverse faults. The reservation area east of the mountains is on the northwestern flank of the Powder River Basin. Therefore, regional dips are eastward and southeastward; however, several prominent structural features interrupt these regional dips. The nearly 4,000 mi{sup 2} reservation is under explored but has strong potential for increased oil and gas development. Oil and gas production is well established in the Powder River Basin of Wyoming to the south as well as in the areas north and west of the reservation. However, only limited petroleum production has been established within the reservation. Geologic relations and trends indicate strong potential for oil and gas accumulations, but drilling has been insufficient for their discovery. The Greybull Sandstone, which is part of the transgressive systems tract that includes the overlying Fall River Sandstone, was deposited on a major regional unconformity. The erosional surface at the base of the Greybull Sandstone is the +100 Ma, late Aptian-Early Albian regional unconformity of Weimer (1984). This lowstand erosional surface was controlled by a basin-wide drop in sea level. In areas where incised Greybull channels are absent, the lowstand erosional unconformity is at the base of the Fall River Sandstone and equivalent formations. During the pre-Greybull lowstand, sediment bypassed this region. In the subsequent marine transgression, streams began to aggrade and deposit sand of the lower Greybull Sandstone


    Energy Technology Data Exchange (ETDEWEB)

    Jennie Ridgley


    An additional 450 wells were added to the structural database; there are now 2550 wells in the database with corrected tops on the Juana Lopez, base of the Bridge Creek Limestone, and datum. This completes the structural data base compilation. Fifteen oil and five gas fields from the Mancos-ElVado interval were evaluated with respect to the newly defined sequence stratigraphic model for this interval. The five gas fields are located away from the structural margins of the deep part of the San Juan Basin. All the fields have characteristics of basin-centered gas and can be considered as continuous gas accumulations as recently defined by the U.S. Geological Survey. Oil production occurs in thinly interbedded sandstone and shale or in discrete sandstone bodies. Production is both from transgressive and regressive strata as redefined in this study. Oil production is both stratigraphically and structurally controlled with production occurring along the Chaco slope or in steeply west-dipping rocks along the east margin of the basin. The ElVado Sandstone of subsurface usage is redefined to encompass a narrower interval; it appears to be more time correlative with the Dalton Sandstone. Thus, it was deposited as part of a regressive sequence, in contrast to the underlying rock units which were deposited during transgression.

  17. Estimates of chemical compaction and maximum burial depth from bedding parallel stylolites (United States)

    Gasparrini, Marta; Beaudoin, Nicolas; Lacombe, Olivier; David, Marie-Eleonore; Youssef, Souhail; Koehn, Daniel


    Chemical compaction is a diagenetic process affecting sedimentary series during burial that develops rough dissolution surfaces named Bedding Parallel Stylolites (BPS). BPS are related to the dissolution of important rock volumes and can lead to porosity reduction around them due to post-dissolution cementation. Our understanding of the effect of chemical compaction on rock volume and porosity evolution during basin burial is however too tight yet to be fully taken into account in basin models and thermal or fluid-flow simulations. This contribution presents a novel and multidisciplinary approach to quantify chemical compaction and to estimate maximum paleodepth of burial, applied to the Dogger carbonate reservoirs from the Paris Basin sub-surface. This succession experienced a relatively simple burial history (nearly continuous burial from Upper Jurassic to Upper Cretaceous, followed by a main uplift phase), and mainly underwent normal overburden (inducing development of BPS), escaping major tectonic stress episodes. We considered one core from the depocentre and one from the eastern margin of the basin in the same stratigraphic interval (Bathonian Sup. - Callovian Inf.; restricted lagoonal setting), and analysed the macro- and micro-facies to distinguish five main depositional environments. Type and abundance of BPS were continuously recorded along the logs and treated statistically to obtain preliminary rules relying the occurrence of the BPS as a function of the contrasting facies and burial histories. The treatment of high resolution 2D images allowed the identification and separation of the BPS to evaluate total stylolitization density and insoluble thickness as an indirect measure of the dissolved volume, with respect to the morphology of the BPS considered. Based on the morphology of the BPS roughness, we used roughness signal analysis method to reconstruct the vertical paleo-stress (paleo-depth) recorded by the BPS during chemical compaction. The

  18. Two Catacombs of Late Sarmatian Time From Pashkovsky Burial Mound no. 2

    Directory of Open Access Journals (Sweden)

    Limberis Natalya Yuryevna


    Full Text Available The article deals with two burials from the Kuban basin region excavated in Pashkovsky burial mound no. 2 belonging to Maeotian Pashkovskoe ancient settlement. The burials were made in catacombs of similar construction and orientation. The narrow grave entrances and grave chambers are situated in-line. The grave chambers of the catacombs adjoin one other that probably was the reason for plunder of a little earlier burial no. 2. There were the complete horse skeleton, the cow skull and the sheep chap in the grave entrance ofthe catacomb no. 2. A skeleton of a man (about 50 years old was in extended supine position diagonally across the grave chamber, his scull had SSW orientation. Grave goods found near the buried man include the gray-clay bowl and the mug-jar, the iron spearhead, the long sword and the dagger, the bit with wheel-shaped cheek-pieces, the sickle, the knives and the shoe buckles, the glass bead, the chalk rock bead, the bronze buckle and fibula. The catacomb no. 2 plundered in ancient times situated north-ward of the first one, the southern border of the grave chamber is partially cutted by catacomb no. 1. In the grave entrance of the catacomb no. 1 there were the remains of the horse skeleton and the sheep skull. Grave goods scattered in grave chamber included the gray-clay bowl, pieces of chalk, the bronze ring, fragments of the iron buckle, rod, hasp, silver temple ring, bronze escutcheon for the box lock, the iron snap-up loop and fragments of silver flacon with a cover. Late Sarmatian burial rites and grave goods give evidence of the belonging these burials to spokesmen of the equestrian order. The chronological range of the burials stays within terms from the second half of 2nd to the middle of 3rd century A.D. The lower date of the catacomb no. 1 turns toward the end of the 2nd century A.D., the upper date is limited by the first half of the 3rd century A.D. The catacomb no. 2 is stratigraphically older. The eques status of

  19. Hydrogeology of the Cambrian-Ordovician aquifer system in the northern Midwest: B in Regional aquifer-system analysis (United States)

    Young, H.L.; Siegel, D.I.


    The Cambrian-Ordovician aquifer system contains the most extensive and continuous aquifers in the northern Midwest of the United States. It is the source of water for many municipalities, industries, and rural water users. Since the beginning of ground-water development from the aquifer system in the late 1800's, hydraulic heads have declined hundreds of feet in the heavily pumped Chicago-Milwaukee area and somewhat less in other metropolitan areas. The U.S. Geological Survey has completed a regional assessment of this aquifer system within a 161,000-square-mile area encompassing northern Illinois, northwestern Indiana, Iowa, southeastern Minnesota, northern Missouri, and Wisconsin.

  20. A highly diverse trilobite fauna with Avalonian affinities from the Middle Cambrian Acidusus atavus Zone (Drumian Stage) of Bornholm, Denmark

    DEFF Research Database (Denmark)

    Weidner, Thomas; Nielsen, Arne Thorshøj


    A newly collected trilobite fauna from the lowermost part of the Alum Shale Formation at Øleå, Bornholm, Denmark, demonstrates the presence of a thin but richly fossiliferous Middle Cambrian Acidusus atavus Zone (Paradoxides paradoxissimus Superzone). The lower part of the zone (the Tomagnostus......, with designation and reillustration of relevant lectotypes. The abundance of polymerid trilobites in comparison with nearby Scania, southern Sweden, where 25 agnostid and nine polymerid species have been reported from equivalent strata, is indicative of a less dysoxic environment in the Bornholm area, which...

  1. First occurrence of a new Ocruranus-like helcionelloid mollusc from the lower Cambrian of East Gondwana

    DEFF Research Database (Denmark)

    Skovsted, Christian B.; Brock, Glenn A.; Topper, Timothy Paul


    A new cap-shaped mollusc, Emargimantus angulatus gen. et sp. nov. is described from the Arrowie Basin of South Australia. The new species is closely comparable to mollusc species from South China and North-East Greenland previously described under the generic name Ocruranus Liu, a genus recently...... reinterpreted as a multiplated, possibly polyplacophoran mollusc. Emargimantus is interpreted as a univalved helcionelloid mollusc and differs from Ocruranus in both morphology and function. E. angulatus represents the first discovery of Ocruranus-like helcionelloids in the lower Cambrian of eastern Gondwana...

  2. Nationwide Surveillance for Pathogenic Microorganisms in Groundwater near Carcass Burials Constructed in South Korea in 2010

    Directory of Open Access Journals (Sweden)

    Ha Kyung Joung


    Full Text Available Widespread outbreaks of foot-and-mouth disease and avian influenza occurred in South Korea during 2010. In response to the culling of many animals to attenuate the spread of disease, South Korea used mass burial sites to dispose of the large number of carcasses; consequently, concerns about groundwater contamination by leachate from these burial sites are increasing. Groundwater is one of the main sources of drinking water, and its cleanliness is directly related to public health. Thus, this study aimed to evaluate the safety of groundwater around the burial sites (total of 600 sites. A total of 1,200 groundwater samples were collected though the country, and microbial analysis was conducted during two time periods: during the spring (n = 600; April to June 2012 and after rainfall (n = 600; August to October, 2012; fall. Fecal coliform and Escherichia coli were detected in 173 (14.4% and 85 (7.1% of the 1,200 samples, respectively. Salmonella spp. and Shigella spp. each were detected only once (0.083%. Clostridium perfringens was detected from 7 groundwater samples (0.583%, and E. coli O157:H7 was not detected. With respect to norovirus, only the GII type was detected from six groundwater samples (0.5%, and enterovirus was detected in 15 groundwater samples (1.25%. The frequency of E. coli that we detected was lower than that found in previous studies conducted in South Korea, but we detected higher frequency of fecal coliform than that observed in a previous report. The contamination frequencies of Salmonella spp. and Shigella spp. were very low, but C. perfringens, which could be an indicator of fecal pollution, was detected in seven regions. Overall, the results of the present study indicate a low possibility of contamination from burial sites. However, consistent monitoring is required to prevent microbial contamination of groundwater near the burial sites.

  3. Estimation of uranium migration parameters in sandstone aquifers. (United States)

    Malov, A I


    The chemical composition and isotopes of carbon and uranium were investigated in groundwater samples that were collected from 16 wells and 2 sources in the Northern Dvina Basin, Northwest Russia. Across the dataset, the temperatures in the groundwater ranged from 3.6 to 6.9 °C, the pH ranged from 7.6 to 9.0, the Eh ranged from -137 to +128 mV, the total dissolved solids (TDS) ranged from 209 to 22,000 mg L(-1), and the dissolved oxygen (DO) ranged from 0 to 9.9 ppm. The (14)C activity ranged from 0 to 69.96 ± 0.69 percent modern carbon (pmC). The uranium content in the groundwater ranged from 0.006 to 16 ppb, and the (234)U:(238)U activity ratio ranged from 1.35 ± 0.21 to 8.61 ± 1.35. The uranium concentration and (234)U:(238)U activity ratio increased from the recharge area to the redox barrier; behind the barrier, the uranium content is minimal. The results were systematized by creating a conceptual model of the Northern Dvina Basin's hydrogeological system. The use of uranium isotope dating in conjunction with radiocarbon dating allowed the determination of important water-rock interaction parameters, such as the dissolution rate:recoil loss factor ratio Rd:p (a(-1)) and the uranium retardation factor:recoil loss factor ratio R:p in the aquifer. The (14)C age of the water was estimated to be between modern and >35,000 years. The (234)U-(238)U age of the water was estimated to be between 260 and 582,000 years. The Rd:p ratio decreases with increasing groundwater residence time in the aquifer from n × 10(-5) to n × 10(-7) a(-1). This finding is observed because the TDS increases in that direction from 0.2 to 9 g L(-1), and accordingly, the mineral saturation indices increase. Relatively high values of R:p (200-1000) characterize aquifers in sandy-clayey sediments from the Late Pleistocene and the deepest parts of the Vendian strata. In samples from the sandstones of the upper part of the Vendian strata, the R:p value is ∼ 24, i.e., sorption processes are

  4. The oxygen content of ocean bottom waters, the burial efficiency of organic carbon, and the regulation of atmospheric oxygen (United States)

    Betts, J. N.; Holland, H. D.


    Data for the burial efficiency of organic carbon with marine sediments have been compiled for 69 locations. The burial efficiency as here defined is the ratio of the quantity of organic carbon which is ultimately buried to that which reaches the sediment-water interface. As noted previously, the sedimentation rate exerts a dominant influence on the burial efficiency. The logarithm of the burial efficiency is linearly related to the logarithm of the sedimentation rate at low sedimentation rates. At high sedimentation rates the burial efficiency can exceed 50% and becomes nearly independent of the sedimentation rate. The residual of the burial efficiency after the effect of the sedimentation rate has been subtracted is a weak function of the O2 concentration in bottom waters. The scatter is sufficiently large, so that the effect of the O2 concentration in bottom waters on the burial efficiency of organic matter could be either negligible or a minor but significant part of the mechanism that controls the level of O2 in the atmosphere.

  5. Sandstone type uranium deposits in the Ordos Basin, Northwest China: A case study and an overview (United States)

    Akhtar, Shamim; Yang, Xiaoyong; Pirajno, Franco


    This paper provides a comprehensive review on studies of sandstone type uranium deposits in the Ordos Basin, Northwest China. As the second largest sedimentary basin, the Ordos Basin has great potential for targeting sandstone type U mineralization. The newly found and explored Dongsheng and Diantou sandstone type uranium deposits are hosted in the Middle Jurassic Zhilou Formation. A large number of investigations have been conducted to trace the source rock compositions and relationship between lithic subarkose sandstone host rock and uranium mineralization. An optical microscopy study reveals two types of alteration associated with the U mineralization: chloritization and sericitization. Some unusual mineral structures, with compositional similarity to coffinite, have been identified in a secondary pyrite by SEM These mineral phases are proposed to be of bacterial origin, following high resolution mapping of uranium minerals and trace element determinations in situ. Moreover, geochemical studies of REE and trace elements constrained the mechanism of uranium enrichment, displaying LREE enrichment relative to HREE. Trace elements such as Pb, Mo and Ba have a direct relationship with uranium enrichment and can be used as index for mineralization. The source of uranium ore forming fluids and related geological processes have been studied using H, O and C isotope systematics of fluid inclusions in quartz veins and the calcite cement of sandstone rocks hosting U mineralization. Both H and O isotopic compositions of fluid inclusions reveal that ore forming fluids are a mixture of meteoric water and magmatic water. The C and S isotopes of the cementing material of sandstone suggest organic origin and bacterial sulfate reduction (BSR), providing an important clue for U mineralization. Discussion of the ore genesis shows that the greenish gray sandstone plays a crucial role during processes leading to uranium mineralization. Consequently, an oxidation-reduction model for

  6. Effect of Various Silica Nanofluids: Reduction of Fines Migrations and Surface Modification of Berea Sandstone

    Directory of Open Access Journals (Sweden)

    Rockey Abhishek


    Full Text Available This work is aimed at addressing surface modification of berea sandstone by silica nanofluids (NFs. Three types of nanofluids were used: silica/deionized water (DIW, silica in DIW with a stabilizer fluid (3-Mercaptopropyl Trimethoxysilane and sulfonate-functionalized silica in DIW. Core flood studies showed that application of silica nanoparticles (NPs improved water injectivity in sandstone. The change in the measured zeta potential indicated surface modification of sandstone by application of NPs. Computation of the surface forces showed that the modified berea sandstone has net attractive potential with fines (obtained from water/rock interaction leading to reduction of fines migration, hence improvement of water injectivity. It was also observed that the silica NPs have greater affinity to adhere/adsorb on quartz surfaces than kaolinite in berea core. This was confirmed by scanning electron microscope imaging and isothermal static adsorption tests. Although the stabilizing of NFs almost did not reduce the fine migration, as was qualitatively indicated by the pressure drop, it enhanced the NPs adsorption on the minerals as obtained by isothermal static adsorption tests. The reduction of fines migration due surface modification by silica NP suggests that NPs can be utilized to overcome the problem of formation damage induced during low salinity flooding in sandstones.

  7. Heavy mineral sorting in downwards injected Palaeocene sandstone, Siri Canyon, Danish North Sea (United States)

    Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan Byskov; Weibel, Rikke


    Post-depositional remobilization and injection of sand are often seen in deep-water clastic systems and have been recently recognised as a significant modifier of deep-water sandstone geometry. Large scale injectite complexes have been interpreted from borehole data in the Palaeocene Siri Canyon near the Danish Central Graben of the North Sea hydrocarbon province. The emplacement of large scale injectite complexes has been commonly attributed to seismic activity and consequent sand liquefaction. However, due to very small differences in textural and compositional properties, and the lack of depositional structures in deep-water sandstones, the distinction between "in situ" and injected or remobilized sandstones is often ambiguous. Large scale heavy mineral sorting (in 10 m thick units) is observed in several reservoir units in the Siri Canyon and has been interpreted to represent the depositional sorting. In this study we describe an example of effective shear-zone sorting of heavy minerals in a thin downwards injected sandstone dyke which was encountered in one of the cores in the Cecilie Field, Siri Canyon. Differences in sorting pattern of heavy minerals are suggested as a tool for petrographic/geochemical distinction between "in situ" sandstones and their related injectites, especially where primary sedimentary structures are removed by fluidization or minor remobilization.

  8. Lithofacies and depositional environment of the Amasiri Sandstone, southern Benue Trough, Nigeria (United States)

    Okoro, A. U.; Igwe, E. O.


    Eight lithofacies typical of tidally-influenced shelf, mass flow and turbidity current processes characterize the Amasiri Sandstone (Cenomanian - Turonian) in the southern Benue Trough, Nigeria. The cross bedded sandstone lithofacies (Sxm) in Afikpo area were deposited in tidally influenced, shallow sandy shoreline environment while similar lithofacies associated with the conglomeratic lithofacies (Sfc) in Akpoha are proximal canyon-fill deposits. The conglomeratic lithofacies with rip-up clasts together with the massive, horizontal-bedded lithofacies (Smm) and parallel-laminated sandstone lithofacies (Sfl) in Akpoha were deposited in confined channels in proximal submarine canyon setting. The wavy/ripple-laminated sandstone lithofacies (Sfw) and very fine grained bioturbated sandstones lithofacies (Sfb) represent weakly confined distributary splay and unconfined associations in proximal to distal submarine canyon settings. The bioturbated mudstone lithofacies (Msb) and parallel-laminated mudstones lithofacies (Msl) comprise the bypass/levees association in the inner to outer shelf and in the distal canyon settings. Overall, these lithofacies indicate deposition in shelf to deep water depositional environments.

  9. The effect of fluid saturation on the dynamic shear modulus of tight sandstones (United States)

    Li, Dongqing; Wei, Jianxin; Di, Bangrang; Ding, Pinbo; Shuai, Da


    Tight sandstones have become important targets in the exploration of unconventional oil and gas reservoirs. However, due to low porosity, low permeability, complex pore structure and other petrophysical properties of tight sandstones, the applicability of Gassmann’s fluid substitution procedure becomes debatable. Aiming at this problem, this paper attempts to explore the applicability of Gassmann’s theory in tight sandstones. Our focus is to investigate the sensitivity of dynamic shear modulus to fluid saturation and the possible mechanism. Ultrasonic velocity in dry and saturated tight sandstone samples was measured in the laboratory under an effective pressure within the range of 1-60 MPa. This study shows that the shear modulus of the water-saturated samples appears to either increase or decrease, and the soft porosity model (SPM) can be used to quantitatively estimate the variation of shear modulus. Under the condition of in situ pressure, samples dominated by secondary pores and microcracks are prone to show shear strengthening with saturation, which is possibly attributed to the local flow dispersion. Samples that mainly have primary pores are more likely to show shear weakening with saturation, which can be explained by the surface energy mechanism. We also find good correlation between changes in shear modulus and inaccurate Gassmann-predicted saturated velocity. Therefore, understanding the variation of shear modulus is helpful to improving the applicability of Gassmann’s theory in tight sandstones.

  10. Evidence for a lack of biological P-cycling in a Cambrian soil (United States)

    Wei, Z.; Peng, Y.; Bao, H.


    The earliest fossil land plants are known to exist in the Mid-Ordovician at 472 to 468 Ma and protein sequence analyses suggest that the onset of land colonization may have begun at as early as ca. 700-1000 million years ago (Ma) . However, fully established soil ecosystem may not be in place until after the Devonian (ca. 400 Ma) or even later. Dearth of fossil record on possible fungi- and/or bacteria-dominated early land biota renders it difficult to establish the early history of land colonization on Earth. Here we present a proxy for soil biological P- cycling. Igneous rock contains typically 0.005-0.4% (wt) phosphate (PO4-3). In a biologically active soil weathering profile, phosphorus (P) is cycled by land biota including by those of the most primitive kingdoms. During, for example, pyrophosphate hydrolysis, the P-O bonds in PO4-3 breaks and exchange oxygen with ambient water. The biologically processed PO4-3 will have typically much higher δ18Ovalues (15-24‰ VSMOW) than the ones inherited from igneous sources (ca. 6‰). Therefore, an increase in the δ18OPO4 from pristine igneous rocks to the upper more weathered ones should be expected if there was an active soil biological P-cycling. An igneous-PO4 δ18O value in the more weathered rocks would otherwise indicate a lack of biologically-mediated P-cycling, thus a lack of or very limited land colonization. We examined a weathering profile in the Elk Point Formation (520-503Ma), South Dakota, a paleosol developed on a metagabbro in a subtropical climate of the Mid-Cambrian. Phosphate was extracted from a drill core of this profile and was analyzed for δ18OPO4. The δ18OPO4 for the weathered and un-weathered igneous rocks are all within a narrow range of 4.8-8.2‰, suggesting that biological P-cycling was insignificant during the weathering of Elk Point metagabbro at ca. 500 Ma. Subaerial, biologically mediated weathering probably did not play a role in geochemical cycling on Earth until much later in

  11. Orogen styles in the East African Orogen: A review of the Neoproterozoic to Cambrian tectonic evolution (United States)

    Fritz, H.; Abdelsalam, M.; Ali, K. A.; Bingen, B.; Collins, A. S.; Fowler, A. R.; Ghebreab, W.; Hauzenberger, C. A.; Johnson, P. R.; Kusky, T. M.; Macey, P.; Muhongo, S.; Stern, R. J.; Viola, G.


    The East African Orogen, extending from southern Israel, Sinai and Jordan in the north to Mozambique and Madagascar in the south, is the world´s largest Neoproterozoic to Cambrian orogenic complex. It comprises a collage of individual oceanic domains and continental fragments between the Archean Sahara-Congo-Kalahari Cratons in the west and Neoproterozoic India in the east. Orogen consolidation was achieved during distinct phases of orogeny between ∼850 and 550 Ma. The northern part of the orogen, the Arabian-Nubian Shield, is predominantly juvenile Neoproterozoic crust that formed in and adjacent to the Mozambique Ocean. The ocean closed during a protracted period of island-arc and microcontinent accretion between ∼850 and 620 Ma. To the south of the Arabian Nubian Shield, the Eastern Granulite-Cabo Delgado Nappe Complex of southern Kenya, Tanzania and Mozambique was an extended crust that formed adjacent to theMozambique Ocean and experienced a ∼650-620 Ma granulite-facies metamorphism. Completion of the nappe assembly around 620 Ma is defined as the East African Orogeny and was related to closure of the Mozambique Ocean. Oceans persisted after 620 Ma between East Antarctica, India, southern parts of the Congo-Tanzania-Bangweulu Cratons and the Zimbabwe-Kalahari Craton. They closed during the ∼600-500 Ma Kuungan or Malagasy Orogeny, a tectonothermal event that affected large portions of southern Tanzania, Zambia, Malawi, Mozambique, Madagascar and Antarctica. The East African and Kuungan Orogenies were followed by phases of post-orogenic extension. Early ∼600-550 Ma extension is recorded in the Arabian-Nubian Shield and the Eastern Granulite-Cabo Delgado Nappe Complex. Later ∼550-480 Ma extension affected Mozambique and southern Madagascar. Both extension phases, although diachronous,are interpreted as the result of lithospheric delamination. Along the strike of the East African Orogen, different geodynamic settings resulted in the evolution of

  12. Disc-shaped fossils resembling porpitids or eldonids from the early Cambrian (Series 2: Stage 4) of western USA (United States)

    Kurkewicz, Richard; Shinogle, Heather; Kimmig, Julien; MacGabhann, Breandán Anraoi


    The morphology and affinities of newly discovered disc-shaped, soft-bodied fossils from the early Cambrian (Series 2: Stage 4, Dyeran) Carrara Formation are discussed. These specimens show some similarity to the Ordovician Discophyllum Hall, 1847; traditionally this taxon had been treated as a fossil porpitid. However, recently it has instead been referred to as another clade, the eldonids, which includes the enigmatic Eldonia Walcott, 1911 that was originally described from the Cambrian Burgess Shale. The status of various Proterozoic and Phanerozoic taxa previously referred to porpitids and eldonids is also briefly considered. To help ascertain that the specimens were not dubio- or pseudofossils, elemental mapping using energy dispersive X-ray spectroscopy (EDS) was conducted. This, in conjunction with the morphology of the specimens, indicated that the fossils were not hematite, iron sulfide, pyrolusite, or other abiologic mineral precipitates. Instead, their status as biologic structures and thus actual fossils is supported. Enrichment in the element carbon, and also possibly to some extent the elements magnesium and iron, seems to be playing some role in the preservation process. PMID:28603667

  13. Redox history of the Three Gorges region during the Ediacaran and Early Cambrian as indicated by the Fe isotope

    Directory of Open Access Journals (Sweden)

    Yusuke Sawaki


    To circumvent this deficiency, we drilled a fossiliferous Ediacaran to Early Cambrian sedimentary succession in the Three Gorges region, South China. We analyzed the iron isotope ratios (δ56/54Fe of pyrite grains in the drill cores using laser ablation multi collector inductively coupled plasma mass spectrometry. The results demonstrate large variations in δ56/54Fe, from −1.6 to 1.6‰, and positive iron isotope ratios are observed in many successions. The presence of positive δ56/54Fe in pyrite indicates that the ferrous iron in the seawater was partially oxidized, suggesting that seawater at Three Gorges was ferruginous during the Ediacaran and Early Cambrian periods. However, aggregated pyrite grains in organic carbon-rich black shales at Member 4 of the Doushantuo Formation and the base of the Shuijingtuo Formation yield near-zero δ56/54Fe values; this suggests that the ocean was transiently dominated by sulfidic conditions during these periods. Notably negative δ56/54Fe values, lower than −1‰, can be interpreted as a signature of DIR. The DIR also might contribute in part to the re-mineralization of organic matter during the largest negative carbon isotope anomaly in the Ediacaran.

  14. Disc-shaped fossils resembling porpitids or eldonids from the early Cambrian (Series 2: Stage 4 of western USA

    Directory of Open Access Journals (Sweden)

    Bruce S. Lieberman


    Full Text Available The morphology and affinities of newly discovered disc-shaped, soft-bodied fossils from the early Cambrian (Series 2: Stage 4, Dyeran Carrara Formation are discussed. These specimens show some similarity to the Ordovician Discophyllum Hall, 1847; traditionally this taxon had been treated as a fossil porpitid. However, recently it has instead been referred to as another clade, the eldonids, which includes the enigmatic Eldonia Walcott, 1911 that was originally described from the Cambrian Burgess Shale. The status of various Proterozoic and Phanerozoic taxa previously referred to porpitids and eldonids is also briefly considered. To help ascertain that the specimens were not dubio- or pseudofossils, elemental mapping using energy dispersive X-ray spectroscopy (EDS was conducted. This, in conjunction with the morphology of the specimens, indicated that the fossils were not hematite, iron sulfide, pyrolusite, or other abiologic mineral precipitates. Instead, their status as biologic structures and thus actual fossils is supported. Enrichment in the element carbon, and also possibly to some extent the elements magnesium and iron, seems to be playing some role in the preservation process.

  15. Atmospheric carbon burial in modern lake basins and its significance for the global carbon budget (United States)

    Einsele, Gerhard; Yan, Jianping; Hinderer, Matthias


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

  16. Petrography and Diagenesis of Palaeocene -Eocene Sandstones in the Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari

       Glaconitic sandstones reservoir in the Siri Canyon are the basis for the investigatation of the geochemical composition of the reservoir sand in cores and also petrographic investigations by optical microscope, scanning electron microscope (SEM) examinations, XRF and microprobe analyses.......   The Palaeogene sequence of the Siri Canyon fill consists of hemipelagic and turbidite marl and claystones interbedded with massive and blocky glauconitic sandstones deposited from sandy mass-flows and sandy turbidites. The Palaeogene sediments in the Danish area are rich in siliceous microfossils as well as late...... zeolites may be common in deep marine sediments, and in volcanoclastic deposits. They are generally related to dissolution of siliceous fossils or diagenetic alteration of volcanic glass. However, authigenic zeolites are common in some of the glauconitic sandstones from the Siri Canyon, where...

  17. [Application of near-infrared spectrum technology to research of weathering of red sandstone relics]. (United States)

    Jiang, Xiao-Dong; Cao, Jian-Jin; Li, Yi-An; Yin, Jin-Long; Ye, Jin-Long


    In the present paper, with near infrared spectroscopy technology, the weathering mechanism of red sandstone relics was studied. Six groups of red sandstone samples were analyzed using near infrared spectroscopy technology. The results show that the near-infrared spectroscopy technology can analyze the material composition of red sandstone before and after weathering, aiming to explore their components changed. So it is a quick and efficient means of research with characteristic of less measurement sample and speed and non-damage and being pollution-free compared with other research techniques. All the characteristic shows that it is also well for studying other stone cultural relics. Especially for those with sampling difficulty and treasure valuable, non-destruction of stone cultural relics is particularly important. So with time advancing, near infrared technology as a research means of stone relics, its meaning will be more prominent.

  18. China action of "Cleanup Plan for Polychlorinated Biphenyls Burial Sites": emissions during excavation and thermal desorption of a capacitor-burial site. (United States)

    Yang, Bing; Zhou, Lingli; Xue, Nandong; Li, Fasheng; Wu, Guanglong; Ding, Qiong; Yan, Yunzhong; Liu, Bo


    Scarce data are available so far on emissions in a given scenario for excavation and thermal desorption, a common practice, of soils contaminated with polychlorinated biphenyls (PCBs). As part of China action of "Cleanup Plan for PCBs Burial Sites", this study roughly estimated PCBs emissions in the scenario for a capacitor-burial site. The concentrations of total PCBs (22 congeners) in soils were in the range of 2.1-16,000μg/g with a mean of 2300μg/g, among the same order of magnitude as the highest values obtained in various PCBs-contaminated sites. Only six congeners belonging to Di-, Tri-, and Tetra-CBs were observed above limits of detection in air samples in the scenario, partially which can be estimated by the USEPA air emission model. Comparing concentrations and composition profiles of PCBs in the soil and air samples further indicated a leaked source of commercial PCBs formulations of trichlorobiphenyl (China PCB no. 1). The measures taken if any to mitigate the volatilization and movement of PCBs and to minimize worker exposure were discussed for improvements of the excavation practice. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Identifying provenance-specific features of detrital heavy mineral assemblages in sandstones (United States)

    Morton, Andrew C.; Hallsworth, Claire


    The composition of heavy mineral assemblages in sandstones may be heavily influenced by processes operating during transport, deposition and diagenesis. As a consequence, conventional heavy mineral data may not be a reliable guide to the nature of sediment source material. Certain features of heavy mineral suites, however, are inherited directly from the source area without significant modification, such as the varietal characteristics of individual mineral species. This paper describes an alternative approach to varietal studies that concentrates on relative abundances of minerals that are stable during diagenesis and have similar hydraulic behaviour. Ratios of apatite to tourmaline, TiO 2 minerals to zircon, monazite to zircon, and chrome spinel to zircon provide a good reflection of the source rock characteristics, because they are comparatively immune to alteration during the sedimentary cycle. These ratios are described as index values (ATi, RZi, MZi and CZi, respectively). This approach avoids some of the practical problems associated with varietal studies, such as the need to make subjective decisions about mineral properties or to use advanced analytical techniques that may not be accessible to the analyst. It also makes use of more components of the heavy mineral suite and thus provides a more balanced view of provenance characteristics. The use of these ratios is illustrated with examples from Upper Jurassic sandstones in the Outer Moray Firth area of the UK continental shelf and Triassic sandstones from onshore and offshore UK. Heavy mineral indices, notably ATi and MZi, show marked variations in Upper Jurassic Piper sandstones of the Outer Moray Firth. Main Piper sandstones have lower ATi and MZi values compared with Supra Piper sandstones, indicating significant stratigraphic evolution of provenance. The UK Triassic shows major regional variations in a number of index values, including ATi, MZi and CZi, demonstrating that sediment was supplied from

  20. CO2-Driven Convection Produced the Vertical Distribution of Sandstone Colors and Iron Concretions in Navajo Sandstone at Zion National Park, Utah (USA) (United States)

    Kettler, R. M.; Loope, D. B.


    Along cliff faces exposed in Zion National Park (SW Utah), the porous and permeable Navajo Sandstone (Jurassic) is 700 m thick, and is capped by impermeable mudrocks and evaporites of the Carmel Formation. Previous workers have documented an areally extensive color pattern that is easily visible across much of southwestern and south-central Utah: the uppermost Navajo Sandstone is nearly white, the middle third of the formation is pink, and the lowermost fraction is reddish brown. To the northwest of the park, however, the formation is uniformly red (likely its primary color; G.B. Nielsen et al., 2009). Spheroidal concretions with dense, iron-oxide-cemented rinds and iron-poor cores are abundant in the pink and brown sandstones. Rhomb-shaped clots of iron oxide cement that are pseudomorphous after siderite are present in the cores of the largest concretions. The color variations are evidence that iron was transported from the upper portion of the Navajo SS to the lower portion. The pseudomorphs are evidence that the concretions are the oxidized remains of siderite-cemented precursors. The vertical iron transport and the precipitation of siderite require similar vertical transport of reducing, CO2-rich formation waters through the Navajo Sandstone. We argue that this circulation was driven in part by groundwater convection beneath a CO2 accumulation that was trapped below the Navajo-Carmel contact. This circulation caused aqueous iron and aqueous carbonate to be displaced downward and to accumulate (in the form of siderite) in the lower Navajo Sandstone. There are numerous CO2 reservoirs in the Colorado Plateau region; the gas was derived mainly from mantle sources. We hypothesize that, in the late Tertiary, the Carmel Formation capped a broad, structurally high accumulation of CO2 and CH4 in the Navajo Sandstone. The CH4 bleached the upper portion of the sandstone, releasing Fe2+ into the formation water. CO2 dissolved in the water, thereby increasing its density

  1. Changes in CaCO3 Burial Trump the Biological Pump (United States)

    Toggweiler, J.; Dunne, J. P.


    The dramatic increases in atmospheric CO2 at the ends of ice ages are usually attributed to a one-two punch coming from the ocean. First, a weakened biological pump vents organically cycled CO2 from the deep ocean via changes in the ventilation of the deep ocean around Antarctica. The initial CO2 increase is then augmented by an enhancement of CaCO3 burial due to a process called CaCO3 compensation (after Broecker, W. S and T.-H. Peng, Global Biogeochem. Cycles, 1, 15-29, 1987). Here, we argue that the importance of the biological pump has been exaggerated. The main effect comes from circulation-induced changes in the burial of CaCO3. As shown in a recent paper by Andreas Schmittner and co-authors (Schmittner, A., E. Brook and J. Ahn, Impact of the ocean's overturning circulation on atmospheric CO2, in Ocean Circulation: Mechanisms and Impacts, Geophys. Monogr. 173, A. Schmittner, J. Chiang, and S. Hemming, eds., pp. 209-246, AGU, 2007) changes in the ventilation of the deep ocean around Antarctica gave rise to 20-30 ppm increases in atmospheric CO2 every 5,000-7,000 years during isotope stages 3 and 4 (30,000 to 70,000 years ago). None of these venting events gave rise to a compensation response. Meanwhile, Jaccard et al. (Science, 308, 1003-1006, 2005) show that all the big CO2 increases during terminations through stage 11 were accompanied by huge increases in CaCO3 burial. This suggests that the enhanced burial of CaCO3 is obligatory rather than compensatory with respect to the dramatic CO2 increases. Broecker and Peng's compensation idea is based on an assumption that the rain of CaCO3 to the sea floor is the same everywhere. More specifically, it assumes that there is no spatial correlation between the production of CaCO3 at the surface and the burial on the sea floor. We find instead that the production and burial of CaCO3 tend to be co-located in regional "hot spots" and that burial in the hot spots balances the input of Ca++ and HCO3- ions in rivers. The

  2. Sandstone/Shale-Brine-CO2 interactions: Implications for Geological Carbon Sequestration (United States)

    Lu, P.; Liu, F.; Fu, Q.; Seyfried, W. E.; Hedges, S.; Griffith, C.; Soong, Y.; Zhu, C.


    The injection of CO2 into deep saline aquifers is presently being considered as an option for greenhouse gas mitigation. However, significant amount of CO2-water-rock interactions brings uncertainties to this potential option because these interactions may either enhance or decrease the potential storage capacity of the reservoirs by dissolution of primary minerals and precipitation of secondary clays. In addition, these reactions may enhance or compromise the mechanical properties of the seals or cap rocks. A series of Sandstone/Shale-Brine-CO2 hydrothermal experiments have been performed at 200 oC, with the addition of CO2 (PCO2 up to 300 bars). Navajo sandstone samples were collected from Black Mesa, Arizona. The Jurassic Navajo/Nugget Sandstone is identified as regionally extensive in the western U.S. and selected as the target for one of the large-volume injection tests by the Big Sky Carbon Sequestration Partnership. Shale chips were obtained from the basal Eau Claire Formation in Southwest of Indiana. Eau Claire Shale overlies Mt. Simon Sandstone which is recognized as a highly promising host reservoir targeted for carbon sequestration by the Midwest Geological Sequestration Consortium (MGSC). Experiments of Navajo sandstones show that silicate minerals in the sandstone display dissolution textures. The formation of carbonate minerals (mineral trapping) is thermodynamically favored and experimentally observed. The chemical reactions likely increase the porosity of the sandstone due to silicate dissolution. However, allophane and illite/smectite cements fill voids of sandstone grains. There is no evidence that suggests the removal of clay coating due to chemical reactions. It is uncertain whether the mechanical forces near in the injection well would mobilize the smectite and allophane and cause pore clogging. In contrast, for CO2-brine-shale system, only minor dissolution of K-feldspar and anhydrite was observed. However, precipitation of pore-filling and

  3. Contribution of thermal radiation in measurements of thermal conductivity of sandstone (United States)

    Zarichnyak, Yu. P.; Ramazanova, A. E.; Emirov, S. N.


    The effective thermal conductivity of sandstone at high pressures of up to 400 MPa and temperatures of 273-523 K has been studied. It has been shown that the degree of crystallization of rock-forming minerals substantially influences the temperature and pressure dependences of the thermal conductivity. The contribution of the radiation heat transfer in measurements of the thermal conductivity of sandstone at various temperatures has been analyzed taking into account the reflection and attenuation of the thermal radiation. The results of measuring the reflection and absorption spectra of the thermal radiation have been presented.

  4. Effects of contamination by geothermal drilling mud on laboratory determinations of sandstone pore properties: an evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, A.; Iglesias, E.; Izquierdo, G.; Guevara, M.; Oliver, R.; Santoyo, S.


    Research to evaluate formation damage related to drilling fluids used in Mexican geothermal fields was initiated. The initial work has been done on Berea sandstone for two reasons: (1) to save valuable reservoir drill cores while developing and turning experimental techniques, and (2) for comparison with results from other investigations, since Berea sandstone has been extensively studied and used in permeability impairment research. The magnitudes of permeability reductions associated with high-temperature rock/geothermal drilling fluid interactions, the possibility of restoring the unperturbed permeability to reservoir drill cores for its measurement in the laboratory were emphasized.

  5. Large difference in carbon emission : burial balances between boreal and arctic lakes


    Lundin, E. J.; J. Klaminder; Bastviken, D; Olid, C.; S. V. Hansson; Karlsson, J


    Lakes play an important role in the global carbon (C) cycle by burying C in sediments and emitting CO2 and CH4 to the atmosphere. The strengths and control of these fundamentally different pathways are therefore of interest when assessing the continental C balance and its response to environmental change. In this study, based on new high-resolution estimates in combination with literature data, we show that annual emission: burial ratios are generally ten times higher in boreal compared to su...

  6. [Deposition and burial of organic carbon in coastal salt marsh: research progress]. (United States)

    Cao, Lei; Song, Jin-Ming; Li, Xue-Gang; Yuan, Hua-Mao; Li, Ning; Duan, Li-Qin


    Coastal salt marsh has higher potential of carbon sequestration, playing an important role in mitigating global warming, while coastal saline soil is the largest organic carbon pool in the coastal salt marsh carbon budget. To study the carbon deposition and burial in this soil is of significance for clearly understanding the carbon budget of coastal salt marsh. This paper summarized the research progress on the deposition and burial of organic carbon in coastal salt marsh from the aspects of the sources of coastal salt marsh soil organic carbon, soil organic carbon storage and deposition rate, burial mechanisms of soil organic carbon, and the relationships between the carbon sequestration in coastal salt marsh and the global climate change. Some suggestions for the future related researches were put forward: 1) to further study the underlying factors that control the variability of carbon storage in coastal salt marsh, 2) to standardize the methods for measuring the carbon storage and the deposition and burial rates of organic carbon in coastal salt marsh, 3) to quantify the lateral exchange of carbon flux between coastal salt marsh and adjacent ecosystems under the effects of tide, and 4) to approach whether the effects of global warming and the increased productivity could compensate for the increase of the organic carbon decomposition rate resulted from sediment respiration. To make clear the driving factors determining the variability of carbon sequestration rate and how the organic carbon storage is affected by climate change and anthropogenic activities would be helpful to improve the carbon sequestration capacity of coastal salt marshes in China.

  7. Hanford facility dangerous waste permit application, low-level burial grounds

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, R.H.


    The Hanford Facility Dangerous Plaste Permit Application is considered to be a single application organized into a General Information Portion (document number DOE/RL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion is limited to Part B permit application documentation submitted for individual, `operating` treatment, storage, and/or disposal units, such as the Low-Level Burial Grounds (this document, DOE/RL-88-20).

  8. Informal Workshop on Burial and Mobility Modeling of Munitions in the Underwater Environment (United States)


    Engineers (USACE) funding (e.g., HEC - RAS – hec - ras /). 4.3. Near Field Versus Far Field Near field...Naval Research PI – Principal Investigator PMRF – Pacific Missile Range Facility RAS – Risk Assessment System RI – Remedial Investigation SERDP...concept for the prototype Risk Assessment System ( RAS ) links output from a probabilistic SERDP REPORT – INFORMAL WORKSHOP ON BURIAL AND MOBILITY

  9. Burial customs of Clazomenae in the iron age (1100-500 BC)


    Ulusoy, Polat


    Ankara : The Department of Archaeology and History of Art, Bilkent University, 2010. Thesis (Master's) -- Bilkent University, 2010. Includes bibliographical references leaves 109-118. The present work is a study on the burial customs of Clazomenae in the Iron Age and Archaic period. Special attention is given to Clazomenae, since it yielded significant information from the Protogeometric to the end of the Archaic period. The major aim here is to collect the specific grave an...

  10. Cleanup Verification Package for the 118-F-3, Minor Construction Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    M. J. Appel


    This cleanup verification package documents completion of remedial action for the 118-F-3, Minor Construction Burial Ground waste site. This site was an open field covered with cobbles, with no vegetation growing on the surface. The site received irradiated reactor parts that were removed during conversion of the 105-F Reactor from the Liquid 3X to the Ball 3X Project safety systems and received mostly vertical safety rod thimbles and step plugs.

  11. Hanford environment as related to radioactive waste burial grounds and transuranium waste storage facilities

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.J.; Isaacson, R.E.


    A detailed characterization of the existing environment at Hanford was provided by the U.S. Energy Research and Development Administration (ERDA) in the Final Environmental Statement, Waste Management Operations, Hanford Reservation, Richland, Washington, December 1975. Abbreviated discussions from that document are presented together with current data, as they pertain to radioactive waste burial grounds and interim transuranic (TRU) waste storage facilities. The discussions and data are presented in sections on geology, hydrology, ecology, and natural phenomena. (JRD)

  12. Short-Term Sediment Burial Effects on the Seagrass Phyllospadix scouleri (United States)


    iwatensis provides structure to trap and retain allochthonous subsidies such as algal drifts and subtidal sea urchins (Hori 2006). While some cases, food for marine mammals, sea turtles, waterfowl and invertebrates (Hemminga and Duarte 2000; Kenworthy et al. 2006). Worldwide they...nutrients (Smith et al. 1988). Shoot density and morphology . Prior to burial, there was no significant difference between the average number of shoots

  13. The Sirius Passet Lagerstätte: silica death masking opens the window on the earliest mat ground community of the Cambrian Explosion

    NARCIS (Netherlands)

    Strang, Katie M; Armstrong, Howard; Harper, David A. T.; Trabucho-Alexandre, João


    The Sirius Passet Lagerstätte (SP), Peary Land, North Greenland, occurs in black slates deposited at or just below storm wave base. It represents the earliest Cambrian microbial mat community with exceptional preservation, predating the Burgess Shale by 10 million years. Trilobites from the SP are

  14. A comparison of burial, maturity and temperature histories of selected wells from sedimentary basins in The Netherlands

    NARCIS (Netherlands)

    Nelskamp, S.; David, P.; Littke, R.


    Sedimentary basins in The Netherlands contain significant amounts of hydrocarbon resources, which developed in response to temperature and pressure history during Mesozoic and Cenozoic times. Quantification and modelling of burial, maturity and temperature histories are the major goals of this

  15. The Sequence of Appearance of Bead Sets at the Filippovka I Burial in the Southern Urals

    Directory of Open Access Journals (Sweden)

    Anikeeva Olga Viktorovna


    Full Text Available The differences in the composition of bead sets from the Filippovka I burial were analyzed by the author in order to determine regularities in their co-occurrence. The mineralogical analysis has revealed the glass beads made of olivine and fluorite. The mineralogical and technological study allowed to classify all beads according to manufacturing techniques. On the basis of the comparison with beads of the same age from India, Persia, Middle Asia, Northern Black Sea coast, the Caucasus, and the Pamir, possible production centers have been hypothesized. The results were compared with earlier published data on bead sets from the Southern Urals burials of the late 6th - early 3rd centuries B.C. The literature data on the timing of appearance and the origin of beads analogous to those from Filippovka barrows were also analyzed. The results suggest that the observed differences in the composition of bead sets reflect the appearance or disappearance of particular bead types in the region. The analysis of mutual occurrence of certain bead types allowed to allocate two groups of the sets which are smoothly replacing each other in time. This allowed the author to reconstruct the sequence of appearance of bead sets in the Filippovka I burial.

  16. Soil burial biodegradation studies of palm oil-based UV-curable films (United States)

    Tajau, Rida; Salleh, Mek Zah; Salleh, Nik Ghazali Nik; Abdurahman, Mohamad Norahiman; Salih, Ashraf Mohammed; Fathy, Siti Farhana; Azman, Anis Asmi; Hamidi, Nur Amira


    The palm oil-based ultraviolet (uv)-curable films were subjected to an outdoor soil burial test to investigate the biodegradation under natural environment. The films were burial in the soil experiment plot at the Nuclear Malaysia's Dengkil complex. The uv-curable films were synthesized from the epoxidized palm oil acrylated (EPOLA) resin and the polyurethane palm oil (POBUA) resin, respectively. Biodegradation tests are more specific to burial film in soil experiments for 12 months under natural conditions. The biodegradability of palm oil resin based uv-curable films were investigated and compared with the petrochemical resin based film. The films properties were compared with respect to properties of the thermal characteristic, the crystallinity, the morphology and the weight loss which are analyzed using the thermogravimetric analysis (TGA), the differential scanning calorimetry (DSC), the scanning electron microscope (SEM), an optical microscope and the weight loss of film calculation. These findings suggested that the palm oil-based uv-curable films show quite satisfactory biodegradation levels.

  17. Soil burial biodegradation studies of palm oil-based UV-curable films

    Energy Technology Data Exchange (ETDEWEB)

    Tajau, Rida, E-mail:; Salleh, Mek Zah, E-mail:; Salleh, Nik Ghazali Nik, E-mail:; Abdurahman, Mohamad Norahiman, E-mail: [Division of Radiation Processing Technology, Malaysia Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Salih, Ashraf Mohammed, E-mail: [Department of Radiation Processing, Sudan Atomic Energy Commission, Khartoum, 1111 Sudan (Sudan); Fathy, Siti Farhana, E-mail: [Laboratory of Molecular Biomedicine, Institute of Bioscience (IBS), Universiti Putra Malaysia (UPM), 43400 UPM, Serdang, Selangor (Malaysia); Azman, Anis Asmi, E-mail:; Hamidi, Nur Amira, E-mail: [School of Chemical Sciences, Universiti Sains Malaysia (USM), 11800 USM, Pulau Pinang (Malaysia)


    The palm oil-based ultraviolet (uv)-curable films were subjected to an outdoor soil burial test to investigate the biodegradation under natural environment. The films were burial in the soil experiment plot at the Nuclear Malaysia’s Dengkil complex. The uv-curable films were synthesized from the epoxidized palm oil acrylated (EPOLA) resin and the polyurethane palm oil (POBUA) resin, respectively. Biodegradation tests are more specific to burial film in soil experiments for 12 months under natural conditions. The biodegradability of palm oil resin based uv-curable films were investigated and compared with the petrochemical resin based film. The films properties were compared with respect to properties of the thermal characteristic, the crystallinity, the morphology and the weight loss which are analyzed using the thermogravimetric analysis (TGA), the differential scanning calorimetry (DSC), the scanning electron microscope (SEM), an optical microscope and the weight loss of film calculation. These findings suggested that the palm oil-based uv-curable films show quite satisfactory biodegradation levels.

  18. Sediment accumulation and carbon burial rates in subpolar fjords of Svalbard, European Arctic (United States)

    Szczucinski, W.; Dominiczak, A.; Forwick, M.; Apolinarska, K.; Moskalik, M.; Woszczyk, M.


    The Svalbard region is particularly sensitive to global climate changes as proved by modern monitoring data and the past records. One of the most evident results is rapid retreat of glaciers during the post-Little Ice Age period (after 1900) observed in many subpolar fjords in Svalbard. The goal of this study is to assess impact of these changes on sediment accumulation rates and carbon burial rate. The study reviews the existing data and provide new high resolution results on 210Pb and 137Cs-based sediment accumulation as well as organic carbon burial rates from a dozen of cores collected in Hornsund fjord, western Spitsbergen. The results prove the sediment accumulation rate to be in order of several mm to several cm/year and large increase in the area of high accumulation rate due to rapid glaciers retreat and formation of new inner fjord bays. In consequence, the total amount of sediment stored in the fjord increases, as well as increase the carbon burial rates. The available data suggest that this kind of fjords may serve as significant sediment and carbon sinks, largely exceeding other polar marine environments. The study was funded by Polish National Science Centre grant No. 2013/10/E/ST10/00166.

  19. Diversity of burial rates in convergent settings decreased as Earth aged. (United States)

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary


    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth's geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma(-1)) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision.

  20. Deconstructing The Stereotypes Of Women Throough A Female Voice In Burial Rites (2013 By Hannah Kent

    Directory of Open Access Journals (Sweden)

    Paramita Ayuningtyas


    Full Text Available Patriarchal society regulates how women should behave and act. If a woman obeys the social rules, she will be labeled as a good woman. On the other hand, if a woman does not follow the social values, she will be immediately categorized as an evil woman and given negative stereotypes. This binary opposition between a good woman and a bad woman is often criticized by the feminists because they think this categorization burdens women. This issue is also highlighted by Hannah Kent in her novel Burial Rites (2013. This novel is set in a rural society in Iceland in the 19th century with its patriarchal values, focusing on a woman named Agnes that will soon be executed. This theme interested the researcher to study Burial Rites more deeply using feminist perspective. Characters, setting and point of view are the intrinsic elements discussed in this research. The result of the analysis shows that through these three elements, Burial Rites describes society’s stereotypes about ‘evil women’ and there is an effort from the author to deconstruct the stereotype through a female voice.

  1. On the Origin of the Dragon Image on the Plate from Shilovka Burial Mound

    Directory of Open Access Journals (Sweden)

    Liphanov Nicolay А.


    Full Text Available The author of the article analyzes an unique image of two opposed dragons engraved on a bone plate discovered in 1992 at barrow No.1 of Shilovka burial mound located on the right bank of the Volga river in Ulyanovsk Oblast (the excavations were conducted by R.S. Bagautdinov. The burial mound is related to the cattle breeding population of late 7th century. The article considers different hypotheses concerning the origin of these dragon images in the artistic traditions of various regions: China (A.V. Komar, D.G. Savinov, B. Totev, Pelevina, Central Asia (V.G. Kotov, V.E. Flyorova, India (N.A. Fonyakova. According to the author, this image has no apparent iconographic parallels in the traditions of these regions. Such analogues are found in the art of the Mediterranean where the ancient images of various mythological creatures exist alongside the image of the sea dragon “ketos” which later became part of the Christian tradition. The appearance of this monster in the images of the first half – middle of the 1st millennium A.D. is practically identical to the dragons from Shilovka burial mound. According to the author, certain impact on the formation of the considered dragon image was made by Iranian art.

  2. A new perspective on studying burial environment before archaeological excavation: analyzing bacterial community distribution by high-throughput sequencing


    Jinjin Xu; Yanfei Wei; Hanqing Jia; Lin Xiao; Decai Gong


    Burial conditions play a crucial role in archaeological heritage preservation. Especially, the microorganisms were considered as the leading causes which incurred degradation and vanishment of historic materials. In this article, we analyzed bacterial diversity and community structure from M1 of Wangshanqiao using 16?S rRNA gene amplicon sequencing. The results indicated that microbial communities in burial conditions were diverse among four different samples. The samples from the robber hole...

  3. Patterns and drivers of change in organic carbon burial across a diverse landscape: Insights from 116 Minnesota lakes (United States)

    Dietz, Robert D.; Engstrom, Daniel R.; Anderson, N. John


    Lakes may store globally significant quantities of organic carbon (OC) in their sediments, but the extent to which burial rates vary across space and time is not well described. Using 210Pb-dated sediment cores, we explored patterns of OC burial in 116 lakes spanning several ecoregions and land use regimes in Minnesota, USA during the past 150-200 years. Rates for individual lakes (across all time periods) range from 3 to 204 g C m-2 yr-1 (median 33 g C m-2 yr-1) and show strong geographic separation in accordance with the degree of catchment disturbance and nutrient enrichment. Climate and basin morphometry exercise subordinate control over OC burial patterns, and diagenetic gradients introduce little bias to estimated temporal trends. Median burial rates in agricultural lakes exceed urban lakes and have increased fourfold since Euro-American settlement. The greatest increase in OC burial occurred prior to the widespread adoption of industrial fertilizers, during an era of land clearance and farmland expansion. Northern boreal lakes, impacted by historical logging and limited cottage development yet comparatively undisturbed by human activity, bury OC at rates 3X lower than agricultural lakes and exhibit much smaller increases in OC burial. Scaling up modern OC burial estimates to the entire state, we find that Minnesota lakes annually store 0.40 Tg C in their sediments, equal to 1.5% of annual statewide CO2 emissions from fossil fuel combustion. During the period of Euro-American settlement (circa 1860-2000), cumulative OC burial amounted to 36 Tg C, 40% of which can be attributed to anthropogenic enhancement.

  4. Characterizing flow pathways in a sandstone aquifer: Tectonic vs sedimentary heterogeneities (United States)

    Medici, G.; West, L. J.; Mountney, N. P.


    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

  5. Petrography and geochemistry of the Middle Miocene Gebel El Rusas sandstones, Eastern Desert, Egypt: Implications for provenance and tectonic setting (United States)

    Zaid, Samir M.


    Petrography and bulk rock geochemistry of the Middle Miocene sandstones of the lower and upper members of Gebel El Rusas Formation along the Egyptian Red Sea Coastal plain, have been investigated to determine the provenance, tectonic setting, and weathering condition of this formation. The Lower Member is formed mainly of sandstones and conglomerates with clay interbeds. The Upper Member is more calcareous and formed mainly of sandstones and limestones with marls and clays intercalations. Petrographically, the Lower Member sandstones are mostly immature and classified as arkoses with an average framework composition of Q_{66}F_{29}R5, and the Upper Member sandstones are partly submature (more quartzose, less feldspathic) and classified as subarkoses with an average framework composition of Q_{80}F_{17}R3. The Gebel El Rusas sandstones are enriched in Sr, Ba, Zr and Rb and depleted in Co and U, as compared to UCC. The chemical index of alteration (CIA) values suggest moderate weathering conditions. The geochemistry results revealed that the Gebel El Rusas sandstones were derived from felsic-granitic source rocks and deposited in a passive margin of a synrift basin. The inferred tectonic setting for Middle Miocene Gebel El Rusas sandstones in the study area is consistent with the regional geology of the Eastern Desert of Egypt during Middle Miocene.

  6. A Cambrian intra-oceanic subduction system in the Bozshakol area, Kazakhstan (United States)

    Shen, Ping; Pan, Hongdi; Seitmuratova, Eleonora; Yuan, Feng; Jakupova, Sholpan


    adakites. Therefore, Bozshakol intrusive rocks were also derived from the mantle wedge and minor slab melts. We propose a model of intra-oceanic subduction for the Middle to Late Cambrian magmatic evolution of magmatic arcs in northwestern central Kazakhstan.

  7. Composition and origin of Early Cambrian Tiantaishan phosphorite-Mn carbonate ores, Shaanxi Province, China (United States)

    Hein, J.R.; Fan, D.; Ye, J.; Liu, T.; Yeh, H.-W.


    The Tiantaishan phosphorite-Mn carbonate ores occur in the Early Cambrian Tananpo Formation in complexly folded and faulted rocks located in southern Shaanxi Province. About 65 x 106 tonnes of 17% P2O5 ore reserves exist and Mn-ore reserves are about 8.3 x 106 tonnes of +18% Mn. The stratigraphic sequence in ascending order consists of black phyllite, black to gray phosphorite ore, black phyllite, rhodochrostone ore, Mn mixed-carbonates, and dolostone. Data are presented from microprobe mineral chemistry, whole-rock chemistry, stable isotopes of carbonates, X-ray mineralogy, petrographic and SEM observations, and statistical analysis of chemical data. The dominant ore-forming minerals are hydroxy- and carbonate fluorapatite and Ca rhodochrosite, with Mg kutnahorite and dolomite comprising the Mn mixed-carbonate section. Pyrite occurs in all rock types and alabandite (MnS) occurs throughout the rhodochrostone section. The mean P2O5 content of phosphorite is 31% and argillaceous phosphorite is 16%, while the mean MnO content of rhodochrostone ore is 37%. Phosphorite ores are massive, spheroidal, laminated, and banded, while rhodochrostone ores have oolitic, spheroidal, and granular fabrics. The most distinguishing characteristics of the ores are high total organic carbon (TOC) contents (mean 8.4%) in the phosphorite and high P2O5 contents (mean 2.7%) in the rhodochrostone ore. The atypically high TOC contents in the Tiantaishan phosphorite probably result from very strong productivity leading to high sedimentation rates accompanied by weak reworking of sediments; poor utilization of the organic matter by bacteria; and/or partial replacement of bacterial or algal mats by the apatite. The depositional setting of the ores was the margin of an epicontinental seaway created as a direct consequence of global processes that included break-up of a supercontinent, formation of narrow seaways, creation of extensive continental shelves, overturn of stagnant, metal-rich deep

  8. Thallium Isotopes Tracking Mn-Oxide Burial - A Proxy for Deoxygenation During Oceanic Anoxic Event 2 (United States)

    Ostrander, C.; Owens, J. D.; Nielsen, S.


    Thallium (Tl) is proving to be a useful paleoredox proxy given that the Tl isotope composition of seawater is highly dependent on the magnitude of manganese (Mn) oxide burial in the ocean. In turn, Mn oxides require oxygen at the sediment-water interface to precipitate, linking the Tl isotope cycle to ocean oxygenation. Currently, the marine residence time of Tl is ~20kyrs and the Tl isotope composition of seawater is invariant, which suggests Tl isotopes could be a global tracer of marine Mn-oxide burial. Importantly, recent research suggests sediments deposited under a euxinic water column faithfully record the Tl isotope value of the overlying oxic water column (e.g. Black Sea and Cariaco Basin). Therefore, analysis of organic-rich black shales may prove useful in evaluating the seawater Tl isotope composition of past oceans and, hence, large-scale burial of Mn-oxides and the extent of bottom water ocean oxygenation. A logical test for this proxy is during the well-studied Cenomanian-Turonian boundary event termed Oceanic Anoxic Event 2 (OAE-2) at ~94 Ma. It is known that the global extent of anoxia and euxinia increased during this event, however, to what extent global bottom water deoxygenation occured is unconstrained. If deep water deoxygenation occurred, it would be hypothesized that Mn-oxide precipitation would decrease, resulting in a positive Tl isotope excursion during OAE-2. We have analyzed the Tl isotope composition of organic-rich black shales from Site 1258 of the Ocean Drilling Program (ODP) spanning the period before, during, and after OAE-2. Based on Fe redox proxies, the entire section is euxinic and thus no Mn-oxides are present (i.e. no local redox changes). Before the event, Tl isotope compositions are similar or slightly heavier than modern seawater values. Just prior to the onset of OAE-2, a positive shift occurs and is maintained until recovery, slightly before the termination of the event. The shift to heavier values and subsequent

  9. Early cretaceous Obernirchen and Bentheim sandstones from Germany used as dimension stone in the Netherlands: geology physical properties, architectural use and comparative weathering

    NARCIS (Netherlands)

    Dubelaar, C.W.; Nijland, T.G.


    The Netherlands, with only scarce occurrences of outcropping or shallow buried natural stone, has over centuries imported huge quantities of Early Cretaceous Bentheim Sandstone and Obernkirchen Sandstone from Germany. The present paper provides an overview of their distribution and properties

  10. [Effects of sand burial on growth and physiological process of Agriophyllum squarrosum seedlings in Horqin Sand Land of Inner Mongolia, North China]. (United States)

    Zhao, Ha-Lin; Qu, Hao; Zhou, Rui-Lian; Wang, Jin; Li, Jin; Yun, Jian-Ying


    In 2010-2011, a sand burial experiment was conducted on the Horqin Sand Land of Inner Mongolia to study the growth characteristics and physiological properties of Agriophyllum squarrosum seedlings under different depths of sand burial. The A. squarrosum seedlings had stronger tolerance against sand burial. The seedling growth could be severely inhibited when the burial depth exceeded seedling height, but some seedlings could still be survived when the burial depth exceeded 1.66 times of seedling height. When the burial depth did not exceed the seedling height, the seedling MDA content and membrane permeability had no significant change, but the lipid peroxidation was aggravated and the cell membrane was damaged with increasing burial depth. Under sand burial stress, the seedling SOD and POD activities and proline content increased significantly, while the seedling CAT activity and soluble sugar content deceased. Sand burial decreased the leaf photosynthetic area and damaged cell membrane, inducing the increase of seedling mortality and the inhibition of seedling growth. The increase of SOD and POD activities and proline content played a definite role in reducing the sand burial damage to A. squarrosum seedlings.

  11. Siliceous spicules in a vauxiid sponge (Demospongia) from the Kaili Biota(Cambrian Stage 5), Guizhou, South China (United States)

    Yang, X.-L.; Zhao, Y.-L.; Babcock, L. E.; Peng, J.


    Fossils of the sponge Angulosuspongia sinensis from calcareous mudstones of the middle and upper part of the Kaili Formation (Cambrian Stage 5) in the Jianhe area of Guizhou province, South China, exhibit an apparently reticulate pattern, characteristic of the Vauxiidae. Energy Dispersive X-Ray Spectrometry (EDS) and Raman spectroscopy analysis indicate the presence of silica in the skeletal elements of these fossils, suggesting that this taxon possessed a skeleton comprised of spicules. This is the first confirmation of siliceous skeletal elements in fossils of the family Vauxiidae, and it lends support to the hypothesis that some early demosponges possessed biomineralized siliceous skeletons, which were subsequently lost and replaced by spongin later in the evolutionary history of this lineage. The new materials provide critical insight into the phylogeny and evolution of biomineralization in the Demosopongiae.

  12. Extensional tectonics and sedimentary response of the Early–Middle Cambrian passive continental margin, Tarim Basin, Northwest China

    Directory of Open Access Journals (Sweden)

    Zhiqian Gao


    Full Text Available The fact that several half-grabens and normal faults developed in the Lower–Middle Cambrian of Tazhong (central Tarim Basin and Bachu areas in Tarim Basin, northwest China, indicates that Tarim Basin was under extensional tectonic setting at this time. The half-grabens occur within a linear zone and the normal faults are arranged in en echelon patterns with gradually increasing displacement eastward. Extensional tectonics resulted in the formation of a passive continental margin in the southwest and a cratonic margin depression in the east, and most importantly, influenced the development of a three-pronged rift in the northeast margin of the Tarim Basin. The fault system controlled the development of platform – slope – bathyal facies sedimentation of mainly limestone-dolomite-gypsum rock-saline rock-red beds in the half-grabens. The NW-SE trending half-grabens reflect the distribution of buried basement faults.

  13. EBSD microfabric study of pre-Cambrian deformations recorded in quartz pebbles from the Sierra de la Demanda (N Spain) (United States)

    Ábalos, B.; Puelles, P.; Fernández-Armas, S.; Sarrionandia, F.


    We describe a new method for the reorientation of lattice preferred orientation data in the absence of a pre-constrained kinematic reference frame. The method enables us to present conventional quartz fabric diagrams after measurements taken from rock sections with a general orientation with respect to foliation and lineation. A microstructural and Electron Back-Scattered Diffraction (EBSD) study of quartz pebbles in early Cambrian conglomerates following this method permit us to recognize a variety of fabrics that resulted from syn-metamorphic ductile deformation under variable temperatures up to 650 °C. The likely source area of the conglomerates was a Proterozoic basement. Candidates for source rock correlations include Neoproterozoic units similar to those outcropping in the northern Iberian Massif, Neoproterozoic medium- to high-grade metamorphic rocks as those outcropping in SW Iberia, or a Neoarchean to Mesoproterozoic concealed basement.

  14. Initiation and propagation of mixed mode fractures in granite and sandstone (United States)

    Rück, Marc; Rahner, Roman; Sone, Hiroki; Dresen, Georg


    We investigate mixed mode fracture initiation and propagation in experimentally deformed granite and sandstone. We performed a series of asymmetric loading tests to induce fractures in cylindrical specimens at confining pressures up to 20 MPa. Loading was controlled using acoustic emission (AE) feedback control, which allows studying quasi-static fracture propagation for several hours. Location of acoustic emissions reveals distinct differences in spatial-temporal fracture evolution between granite and sandstone samples. Before reaching peak stress in experiments performed on granite, axial fractures initiate first at the edge of the indenter and then propagate through the entire sample. Secondary inclined fractures develop during softening of the sample. In sandstone, inclined shear fractures nucleate at peak stress and propagate through the specimen. AE source type analysis shows complex fracturing in both materials with pore collapse contributing significantly to fracture growth in sandstone samples. We compare the experimental results with numerical models to analyze stress distribution and energy release rate per unit crack surface area in the samples at different stages during fracture growth. We thereby show that for both rock types the energy release rate increases approximately linearly during fracture propagation. The study illuminates how different material properties modify fracture initiation direction under similar loading conditions.

  15. Structural changes in the surface of a heterogeneous nanocrystalline body (sandstone) under the friction (United States)

    Vettegren, V. I.; Ponomarev, A. V.; Sobolev, G. A.; Shcherbakov, I. P.; Mamalimov, R. I.; Kulik, V. B.; Patonin, A. V.


    The structure of a 30 nm thick surface layer of a heterogeneous nanocrystalline solid body (sandstone) before and after the friction was investigated using photoluminescence and Raman spectroscopy. Before the friction, this layer contained nanocrystals of quartz, anatase, feldspar, and montmorillonite. The friction caused a sharp decrease in the concentration of nanocrystals of quartz and feldspar.

  16. Original and pyrometamorphical altered Bentheimer sandstone : Petrophysical properties, surface and dielectric behavior

    NARCIS (Netherlands)

    Peksa, A.E.; Wolf, K.H.A.A.; Slob, E.C.; Chmura, L.A.; Zitha, P.L.J.


    Bentheimer sandstone is a quartz-rich permeable hard sedimentary rock used for core flooding experiments. When fired to stabilize clays (subjected to high temperatures), pyrometamorphical phase changes induce texture and pore framework alteration. As a consequence the new dielectric response may

  17. A new biostratigraphical tool for reservoir characterisation and well correlation in permo-carboniferous sandstones

    NARCIS (Netherlands)

    Garming, J.F.L.; Cremer, H.; Verreussel, R.M.C.H.; Guasti, E.; Abbink, O.A.


    Permo-Carboniferous sandstones are important reservoir rocks for natural gas in the Southern North Sea basin. This is a mature area which makes tools for reservoir characterization and well to well correlation important for field optimalisation and ongoing exploration activities. Within the

  18. Concurrent nitrate and Fe(III) reduction during anaerobic biodegradation of phenols in a sandstone aquifer

    DEFF Research Database (Denmark)

    Broholm, Mette; Crouzet, C.; Arvin, Erik


    The biodegradation of phenols (similar to 5, 60, 600 mg 1(-1)) under anaerobic conditions (nitrate enriched and unamended) was studied in laboratory microcosms with sandstone material and groundwater from within an anaerobic ammonium plume in an aquifer, The aqueous phase was sampled and analyzed...

  19. Prediction of calcite Cement Distribution in Shallow Marine Sandstone Reservoirs using Seismic Data

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, N.E.


    This doctoral thesis investigates how calcite cemented layers can be detected by reflection seismic data and how seismic data combined with other methods can be used to predict lateral variation in calcite cementation in shallow marine sandstone reservoirs. Focus is on the geophysical aspects. Sequence stratigraphy and stochastic modelling aspects are only covered superficially. Possible sources of calcite in shallow marine sandstone are grouped into internal and external sources depending on their location relative to the presently cemented rock. Well data and seismic data from the Troll Field in the Norwegian North Sea have been analysed. Tuning amplitudes from stacks of thin calcite cemented layers are analysed. Tuning effects are constructive or destructive interference of pulses resulting from two or more closely spaced reflectors. The zero-offset tuning amplitude is shown to depend on calcite content in the stack and vertical stack size. The relationship is found by regression analysis based on extensive seismic modelling. The results are used to predict calcite distribution in a synthetic and a real data example. It is found that describing calcite cemented beds in shallow marine sandstone reservoirs is not a deterministic problem. Hence seismic inversion and sequence stratigraphy interpretation of well data have been combined in a probabilistic approach to produce models of calcite cemented barriers constrained by a maximum amount of information. It is concluded that seismic data can provide valuable information on distribution of calcite cemented beds in reservoirs where the background sandstones are relatively homogeneous. 63 refs., 78 figs., 10 tabs.

  20. Seasonal Deep Aquifer Thermal Energy Storage in the Gassum Sandstone Formation

    DEFF Research Database (Denmark)

    Holmslykke, H.D.H.; Kjøller, C.; Fabricius, Ida Lykke

    Seasonal storage of excess heat in hot deep aquifers is considered to optimise the usage of commonly available energy sources. The potential chemical reactions caused by heating the Gassum Sandstone Formation to up to 150°C is investigated by core flooding experiments combined with petrographic...

  1. Comparative Analysis of the Strength Distribution for Irregular Particles of Carbonates, Shale, and Sandstone Ore

    Directory of Open Access Journals (Sweden)

    Alona Nad


    Full Text Available The article presents the results of investigations on three lithological types of Polish copper ore: sandstone ore, carbonate ore, and shale ore. According to X-ray diffraction analysis, sandstone samples can be classified as sandstone with dolomite binder and partly clay binder; shale—as dolomitic slate with a high proportion of clay with elevated organic matter content; while dolomite has a high organic content. Five particle-sized fractions (16–18 mm, 18–20 mm, 20–25 mm, 25–31.5 mm, and 31.5–45 mm of each lithological type were prepared. A single-axis slow-compression test was performed on single particles to determine the value of the crushing force. The Weibull distribution was used to approximate the strength distribution models and cumulative strength distribution functions for each of the materials. The residual deviation and non-linear correlation coefficient were calculated in order to assess the fitting of the model function to empirical data. In addition, the impact of particle size on the strength of the raw material was separately investigated for the hard (dolomite and shale and soft brittle material (sandstone.

  2. Quantitative study of a rapidly weathering overhang developed in an artificially wetted sandstone cliff

    Czech Academy of Sciences Publication Activity Database

    Bruthans, J.; Filippi, Michal; Schweigstillová, Jana; Řihošek, J.


    Roč. 42, č. 5 (2017), s. 711-723 ISSN 0197-9337 R&D Projects: GA ČR GA13-28040S Institutional support: RVO:67985831 ; RVO:67985891 Keywords : sandstone overhang * retreat * frost weathering * erosion rate * stress Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.697, year: 2016

  3. Zeolites in the Miocene Briones Sandstone and related formations of the central Coast Ranges, California (United States)

    Murata, K.J.; Whiteley, Karen R.


    Authigenic zeolites present in the generally tuffaceous Miocene Briones Sandstone and related formations of the central Coast Ranges of California indicate three stages of diagenetic history: (1) Initial alteration of pyroclastic materials to clinoptilolite (and montmorillonite) that is widely distributed in small amounts throughout the region. (2) Subsequent crystallization of heulandite followed by stilbite in fractures at a few places. (3) Widespread development of laumontite in only the southern part of the region, where the sandstone appears to have been downfolded and faulted to greater depths than elsewhere. Laumontite occurs both as pervasive cement of sandstone and as filling of fractures, and was produced through the reaction of interstitial solutions with other zeolites and with such major constituents of the sandstone as plagioclase, montmorillonite, and calcite at temperatures of 100° C or higher. Mordenite was found at only one locality, closely associated with clinoptilolite and opal. Analcite occurs in diverse settings, and its relation to the other zeolites is obscure.  Sparry calcite and coexisting stilbite, laumontite, or analcite in veins seem to make up nonequilibrium assemblages.

  4. Sources of the elements in the sandstone-type uranium deposits of the Colorado Plateau (United States)

    Shoemaker, Eugene M.; Newman, W.L.; Miesch, A.T.


    Sandstone-type uranium deposits of the Colorado Plateau are epigenetic. Certain elements have been added locally to the sandstone host to form the deposits; the added fraction of each element in the deposits is call extrinsic to distinguish it from the part present in the original unmineralized host. The principal extrinsic components, in their approximate order of abundance, are vanadium, iron magnesium, uranium, sulfur, arsenic, copper, lead, molbedenum, selenium, cobalt, and nickel. At lest six possible sources of the extrinsic components of the uranium deposits may be considered reasonably likely: 1) the sandstone beds enclosing the uranium deposits, 2) the marine Mancos shales of Cretaceous ages, 3) bentonitic shales of Jurassic and Triassic age, 4) petroliferous rocks of Pennsylvanian age, 5) Precambrian crystalline rocks underlying the Colorado Plateau, and 6) magmatic reservoirs of latest Cretaceous or Tertiary age. If the major source of some of the elements of external to the sandstone beds enclosing the deposits, it is likely that several sources have contributed to some if not most of the extrinsic components and that the importance of the various sources differs from one component to the next. Precambrian crystalline rocks are considered the most likely major source of the extrinsic uranium in the deposits.

  5. The sedimentary facies characteristics and lithofacies palaeogeography during Middle-Late Cambrian, Sichuan Basin and adjacent area

    Directory of Open Access Journals (Sweden)

    Feifan Lu


    Full Text Available Combined with the regional strata filling characteristics of Middle-Upper Cambrian, the present paper conducts a systematic research on sedimentary facies in the basin and its peripheral area by utilizing 164 field outcrops and drilling and coring data. Further, the method of “multi-factor comprehensive synthesis based on single-factor analysis” was employed to investigate the sedimentary facies and palaeogeography of the study area and establish the sedimentary facies model. Stratigraphic reveals that the study area represents the pattern of thin-northwest and thick-southeast by stretching northeast-southwest. Within the present basin, the pattern of “one thin and two thick” predominates, while outside the basin “four thin and three thick” filling feature was found. Sedimentary facies shows that the study area was featured by rimmed carbonate platform. Specifically, carbonate platform, slope and northeastern corner Qinling paleooceanic Basin and southeastern corner Jiangnan Bain was identified from the west to the east. The carbonate platform contains restricted platform, evaporation-restricted platform, semi-restricted platform and the platform margin. Single factor analysis and lithofacies palaeogeographic characteristics manifests that during Middle-Late Cambrian, the western Old land evolved into peneplain stage, and that the eastern and southwestern sub-sags remained connected to the open-sea to some extent. At the time, the shllow seawater circulation was relatively restricted, while the ancient seabed tended to be flat and evaporation characteristics significantly diminished. Secondary sea-level fluctuation intensively influenced the development of scaled grain beach. It is suggested that tide marginal beach, intraplatform shoal subfacies zone, along with Shiqian-SangZhi in southeast and Zhenba-Xinshan in northeast platform-margin beach subfacies zone to be preferable targets for the favorable reservoir facies zone and

  6. Lower Cambrian-Ediacaran Paleogeography and True Polar Wander with New Paleomagnetic Constraints from West African Craton (United States)

    Robert, B.; Besse, J.; Blein, O.; Greff-Lefftz, M.; Baudin, T.; Fernando, L.; Meslouh, S.; Belbadaoui, M.


    Paleomagnetic data from Laurentia and Baltica continents suggest fast large oscillations of the virtual geomagnetic poles (VGP) from high to low latitudes during the Ediacaran (635-542 Ma). These data are interpreted in the literature either as oscillations of the Earth magnetic dipole between polar and equatorial positions, or as True Polar Wander (TPW), implying a very fast tumbling of continents and perhaps, of whole Earth. In this study, we try to test these hypotheses by bringing new paleomagnetic data on volcanic series from another continent, the West African Craton (WAC). We have sampled well dated pyroclastic and lava flows from the Ouarzazate and Taroudant groups in the Anti-Atlas, (Morocco). 480 samples from 105 sites were thermally demagnetized in our laboratory. Our preliminary results highlight two major groups of directions, mainly carried by hematite, magnetite also contributing sometimes to the magnetization. The first group consists of a dual polarity high inclination direction that may represent the original magnetization. The observed paleolatitude is compatible with that predicted by the lower Cambrian-Ediacaran apparent polar wander path (APWP) of Gondwana, assuming that the WAC was already accreted to Gondwana at this age. Nevertheless, a complete agreement between our pole and the APWP needs a local rotation of around 80° on a vertical axis. The second group displays a single polarity direction, with a shallow inclination and a south-east declination. This direction is close to the expected direction derived from the Permo-Carboniferous segment of the Gondwana APWP, and may represent a remagnetization acquired during the Kiaman reversed polarity superchron. Our preliminary paleomagnetic results thus display large changes in the VGP position, as also evidenced by others on Baltica and Laurentia. However, their interpretation does not favor TPW episodes or equatorial Earth magnetic dipole during the lower Cambrian-Ediacaran periods, but

  7. Continuity and internal properties of Gulf Coast sandstones and their implications for geopressured energy development. Annual report, November 1, 1980-October 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Morton, R.A.; Ewing, T.E.; Tyler, N.


    Systematic investigation, classification, and differentiation of the intrinsic properties of genetic sandstone units that typify many geopressured geothermal aquifers and hydrocarbon reservoirs of the Gulf Coast region are provided. The following are included: structural and stratigraphic limits of sandstone reservoirs; characteristics and dimensions of Gulf Coast Sandstones; fault compartment areas; comparison of production and geologic estimates of aquifer volume; geologic setting and reservoir characteristics, wells of opportunity; internal properties of sandstones and implications for geopressured energy development. (MHR)

  8. Two items: Transcription of a presentation by Dr. E. L. Albenesius, ``SRS burial ground operation from an historical perspective``; video tape entitled ``Burial ground operation``

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, H.P.


    On February 6, 1992, approximately 35 SRS personnel from DOE, WSRC, and Dames and Moore attended a very informative talk given by Dr. E.L. Albenesius who discussed the operation of the SRS Burial Ground from an historical perspective. Dr. Albenesius, a Du Point retiree, formerly served as research manager of SRL`s Environmental Effects and Solid Waste Management Technology Divisions among other assignments. One notable point Dr. Albenesius made was in answer to a question concerning what was the most important thing that could be done to reduce the hazard to man from buried waste. His response was to remove as much plutonium as practical prior to closure. In order to preserve this valuable information for the record, the program was audiotaped from which a point-by-point chronological transcription, with minor editing, was prepared.

  9. Sandstone geomorphology of the Golden Gate Highlands National Park, South Africa, in a global context

    Directory of Open Access Journals (Sweden)

    Stefan W. Grab


    Full Text Available The Golden Gate Highlands National Park (GGHNP is well known for its impressive sandstone formations. While previous geoscience research in the park has focused on geology, palaeontology, slope forms and the prominent lichen weathering, remarkably little has been written on the diversity and possible origins of sandstone phenomena in the region. The objectives of this study were (1 to present a geomorphological map of prominent and interesting landforms for particular portions of the park and (2 to document the variety of macro- and microscale sandstone formations observed. During field work, we undertook global positioning system measurements to map landforms and, in addition, measured the dimensions of several landform types. A Schmidt hammer was used to conduct rock hardness tests at a variety of localities and lithologies for comparative purposes. We indentified and mapped 27 macro- and microscale sandstone landforms, of which 17 are described in detail. It is demonstrated that for the most part, the landforms are a likely product of surface lithological reactions to a regional climate characterised by pronounced multitemporal temperature and moisture shifts, recently and in the past. However, many of the geomorphological processes producing landforms are controlled by microclimates set up by factors such as macro- and microtopography. Conservation implications: The GGHNP is best known for its geological, geomorphological and palaeontological heritage. This paper highlights the diversity of sandstone geomorphological phenomena, many of them rare and ‘unique’ to the region. Not only are these landforms of aesthetic interest to tourists, but they also provide microhabitats for biota. Thus, conservation of biota requires associated conservation of geo-environments where they are established.

  10. Changes of petrophysical properties of sandstones due to interaction with carbon dioxide, a laboratory study (United States)

    Nover, Georg; von der Gönna, Jutta; Heikamp, Stephanie; Köster, Jens


    Changes of petrophysical, petrological, mineralogical, mechanical and chemical parameters were studied on sandstones from the Hessian depression and sandstones from Neidenbach (Eifel) before and after alteration with CO2. The experiments were performed in a wide pressure and temperature range (p >10 10085 weight %, density from 2.62 - 2.70 g/cm3, porosity from 25% and permeability from order in magnitude for i) and more than 1.5 orders in magnitude for ii). The mineralogical composition was unchanged within the detection limit of powder X-Ray diffraction (XRD), while X-Ray Fluorescence Analysis (XRF) indicated mobilization of calcium, magnesium, aluminum and potassium. Dissolution was confirmed by the chemical analysis (ICP-OES-MS) of recovered artificial brines that showed an increase of the ionic species Ca, Mg, Al and K after the scCO2-experiments. Partial solution of feldspar and clay was detected by optical inspection and scanning electron microprobe SEM-analysis. Low frequency electrical conductivity experiments (SIP, spectral induced polarization) exhibited both, a significant increase in conductivity that could be explained by dissolution at narrow pore throats thus causing a higher degree of interconnection of the pore system and a shift of the phase angle that indicates changes of the geometry of the pore surface area. The uniaxial compressive strength was measured before and after scCO2-treatment on a set of homogeneous sandstones from Neidenbach. These data were compared with natural analogues, e.g. bleached and unbleached sandstones from the Hessian depression. The uniaxial compressive strength of untreated and scCO2-treated samples were found to fit the range reported for sandstones.

  11. Multiple stages of aqueous alteration along fractures in mudstone and sandstone strata in Gale Crater, Mars (United States)

    Yen, A. S.; Ming, D. W.; Vaniman, D. T.; Gellert, R.; Blake, D. F.; Morris, R. V.; Morrison, S. M.; Bristow, T. F.; Chipera, S. J.; Edgett, K. S.; Treiman, A. H.; Clark, B. C.; Downs, R. T.; Farmer, J. D.; Grotzinger, J. P.; Rampe, E. B.; Schmidt, M. E.; Sutter, B.; Thompson, L. M.; MSL Science Team


    The Mars rover Curiosity in Gale crater conducted the first-ever direct chemical and mineralogical comparisons of samples that have clear parent (unaltered) and daughter (altered) relationships. The mineralogy and chemistry of samples within and adjacent to alteration halos in a sandstone formation were established by the Chemistry and Mineralogy (CheMin) X-ray diffraction (XRD) instrument and the Alpha Particle X-ray Spectrometer (APXS), respectively. The Stimson formation sandstones unconformably overlie the Murray mudstone formation and represent the youngest stratigraphic unit explored by Curiosity to date. Aqueous alteration of the parent sandstone resulted in a loss of half of the original crystalline mineral phases and a three-fold increase in X-ray amorphous material. Aqueous fluids extensively leached Mg, Al, Mn, Fe, Ni, Zn and other elements from the parent material, decreased the pyroxene to feldspar ratio by a factor of two, introduced Ca and mixed-cation sulfates, and both passively and actively enriched the silica content. Leaching of Mg, Al, Mn, Fe, Ni and Zn and enrichment of Si and S are also observed in alteration halos in the underlying mudstone. These observations are consistent with infiltration of subsurface fluids, initially acidic and then alkaline, propagating along fractures crosscutting the Stimson sandstone and Murray mudstone. The geochemistry and mineralogy suggest a complicated diagenetic history with multiple stages of aqueous alteration under a variety of environmental conditions (e.g. both low and moderate pH). The formation of these alteration halos post-dates lithification of the sandstones and mudstones and represents one of the youngest hydrogeologic events presently known to have occurred in Gale crater.

  12. Elemental Gains/Losses Associated with Alteration Fractures in an Eolian Sandstone, Gale Crater, Mars (United States)

    Ming, D. W.; Yen, A. S.; Gellert, R.; Sutter, B.; Berger, J. A.; Thompson, L. M.; Schmidt, M. E.; Morris, R. V.; Treiman, A. H.


    The Mars Science Laboratory rover Curiosity has traversed up section through approximately 100 m of sedimentary rocks deposited in fluvial, deltaic, lacustrine, and eolian environments (Bradbury group and overlying Mount Sharp group). The Stimson formation unconformably overlies a lacustrine mudstone at the base of the Mount Sharp group and has been interpreted to be a cross-bedded sandstone of lithified eolian dunes. Unaltered Stimson sandstone has a basaltic composition similar to the average Mars crustal composition, but is more variable and ranges to lower K and higher Al. Fluids passing through alteration "halos" adjacent to fractures have altered the chemistry and mineralogy of the sandstone. Elemental mass gains and losses in the alteration halos were quantified using immobile element concentrations, i.e., Ti (taus). Alteration halos have elemental gains in Si, Ca, S, and P and large losses in Al, Fe, Mn, Mg, Na, K, Ni, and Zn. Mineralogy of the altered Stimson is dominated by Ca-sulfates, Si-rich X-ray amorphous materials along with plagioclase feldspar, magnetite, and pyroxenes. The igneous phases were less abundant in the altered sandstone with a lower pyroxene/plagioclase feldspar. Large elemental losses suggest acidic fluids initially removed these elements (Al mobile under acid conditions). Enrichments in Si, Ca, and S suggest secondary fluids (possibly alkaline) passed through these fractures leaving behind X-ray amorphous Si and Ca-sulfates. The mechanism for the large elemental gains in P is unclear. The geochemistry and mineralogy of the altered sandstone suggests a complicated diagenetic history with multiple episodes of aqueous alteration under a variety of environmental conditions (e.g., acidic, alkaline).

  13. The Structure of Sandstones in Productive Horizons of the Permian Bituminous Deposits of Tatarstan (Russia

    Directory of Open Access Journals (Sweden)

    R.R. Khasanov


    Full Text Available The features of sandstones in productive horizons of the Permian bituminous deposits of Tatarstan (Russia have been considered. The composition and internal structure of sandstones have been studied by optical microscopy, electron paramagnetic resonance (EPR, and electron microscopy, as well as using a number of physical and chemical methods to solve special problems. The investigated sandstones belong to the greywacke group. The clastic material of sandstones contains grains of feldspar, quartz, mica, and particles of volcanic rocks. The nature and composition of cement are important parameters that determine the filtration-capacity properties of sedimentary rocks. Bituminous deposits are characterized by vertical zoning, which is expressed in the alternation of sites with varying degrees of cementation of rocks. Atten-tion has been also paid to post-sedimentation processes, such as pyritization and calcification. Pyrite forms rare xenomorphic isometric grains. The formation of pyrite occurs in diagenesis and is associated with the processes of biogenic sulfate reduction. The source of calcium for the crystallization of dispersed cal-cite in the porous space of sandstones is the underground waters of red-colored Ufimian deposits characterized by the alkaline properties favorable for calcium migration. According to the data of X-ray computed tomography, the internal space of the studied rocks is not homogeneous and represented by a system of communicated and isolated pores. In the studied samples, two types of organic matter differing in organic radicals have been detected. The first type is an organic substance of coal origin. The second type of organic matter belongs to the oil origin and refers to bitumens in its properties. The presence of a significant percentage of asphaltenes in the bitumen composition indicates the destruction of the oil substance in the near-surface conditions.

  14. Sulfur and strontium isotopic compositions of carbonate and evaporite rocks from the late Neoproterozoic–early Cambrian Bilara Group (Nagaur-Ganganagar Basin, India): Constraints on intrabasinal correlation and global sulfur cycle

    Digital Repository Service at National Institute of Oceanography (India)

    Mazumdar, A.; Strauss, H.

    deposits of terminal Neoproterozoic to early Cambrian age. Lithological and geochemical results suggest the coeval nature of the Bilara Group and Hanseran Evaporite Group. Fluctuations in the sulfur isotopic composition may at least partially be attributed...

  15. Characterization of the Hanford 300 area burial grounds. Final report: decontamination and decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, S.J.; Ames, L.L.; Fitzner, R.E.; Gee, G.W.; Sandness, G.A.; Simmons, C.S.


    Pacific Northwest Laboratory conducted a series of investigations at the Hanford Site to develop technologies for characterizing and monitoring radioactive waste burial facilities that could be used in determining appropriate decommissioning alternatives. Specific objectives were to develop unique functional geophysics, geochemical, soil physics, numerical modeling, and biological methodologies needed to better characterize and monitor buried radioactive waste disposal sites. To meet these objectives the project was divided into four tasks: Task I, Geophysical Evaluation - Geophysical surveys were taken to locate and define the gross composition of waste materials. Task II, Geochemical Analysis - The interaction of disposed radionuclides with geologic media was analyzed through an integrated radiochemical procedure. Task III, Fluid Transport and Modeling - Computer modeling of water migration in partially saturated groundwater systems was verified with actual data collected at a field test facility used to monitor micrometeorological and geohydrological energy and mass transfer factors. Task IV, Biological Transport - Several biological organisms were evaluated for potential radionuclide uptake and transport. Along with the four tasks, the project included a review of pertinent literature and regulatory issues that might affect the alternatives selected. Surveys were taken of the surrounding area and specific sites and operations. The overall results indicated that the 300 Area Burial Grounds have been adequate in containing radioactive waste. Based on the results of the project, the alternatives identified for decommissioning these sites are exhumation and translocation, entombment, perpetual care, and abandonment. Perpetual care (currently used) appears to be the best decommissioning alternative for these burial grounds at this time. However, another alternative may be selected depending on future waste management policies, plans, or activities.

  16. Zostera marina seed burial can be enhanced by Manila clam Ruditapes philippinarum: A microcosm study (United States)

    Li, Chang-Jun; Li, Wen-Tao; Liu, Jianying; Zhang, Xiumei; Zhang, Peidong


    Seagrass seed bank plays a key role in the regeneration of new vegetation when seagrasses are removed by the natural or man-made disaster. Various factors may affect the development of sediment seed bank. We conducted a microcosm experiment to test the effects of burrowing and feeding activities of Manila clam, Ruditapes philippinarum on the burial of Zostera marina seeds in sediments. The effects of lasting time (3-hour, 1-day, 3-day, 7-day, 14-day and 28-day), clam density (0, 2, 4 and 8 clams with shell length of 3 cm in each microcosm) and clam size (shell length of 2, 3 and 4 cm at 4-clam density) on seed burial were examined in plastic microcosm cores (30 cm high × 10 in inner diameter) in a 28-day period. Results showed that the seed burial depth significantly increased with time, the density and the size of clams. No seeds were buried in the sediment in the cores without clams during the whole experiment period. For the 3-cm clams, about 91.61% of the seeds were buried in the sediment at the end of the experiment in the high-density treatment (8 clams at each core); while in the medium and low-density treatments (4 and 2 clams in each core, respectively), about 76.93% and 60.61% of the seeds were buried in the sediment, respectively. For the size treatments, large (4 cm) clams buried 89.56% of the seeds at the end of the experiment, much more than those of medium (3 cm, 76.93%) and small (2 cm, 61.50%) size clams. During the whole experiment period, nearly all of the buried seeds were at a depth of from 0 cm to 5 cm. These results suggested that Manila clam Ruditapes philippinarum may play an important positive role in seagrass seed bank dynamics in the field.

  17. Measurement of water potential in low-level waste management. [Shallow Land Burial

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T. L.; Gee, G. W.; Kirkham, R. R.; Gibson, D. D.


    The measurement of soil water is important to the shallow land burial of low-level waste. Soil water flow is the principle mechanism of radionuclide transport, allows the establishment of stabilizing vegetation and also governs the dissolution and release rates of the waste. This report focuses on the measurement of soil water potential and provides an evaluation of several field instruments that are available for use to monitor waste burial sites located in arid region soils. The theoretical concept of water potential is introduced and its relationship to water content and soil water flow is discussed. Next, four major areas of soils research are presented in terms of their dependence on the water potential concept. There are four basic types of sensors used to measure soil water potential. These are: (1) tensiometers; (2) soil psychrometers; (3) electrical resistance blocks; and (4) heat dissipation probes. Tensiometers are designed to measure the soil water potential directly by measuring the soil water pressure. Monitoring efforts at burial sites require measurements of soil water over long time periods. They also require measurements at key locations such as waste-soil interfaces and within any barrier system installed. Electrical resistance blocks are well suited for these types of measurements. The measurement of soil water potential can be a difficult task. There are several sensors commercially available; however, each has its own limitations. It is important to carefully select the appropriate sensor for the job. The accuracy, range, calibration, and stability of the sensor must be carefully considered. This study suggests that for waste management activities, the choice of sensor will be the tensiometer for precise soil characterization studies and the electrical resistance block for long term monitoring programs. (DMC)

  18. Post-breakup burial and exhumation of passive continental margins: nine propositions to inform geodynamic models (United States)

    Green, Paul F.; Duddy, Ian; Japsen, Peter; Chalmers, James; Bonow, Johan


    Despite many years of study, the processes involved in the post-breakup development of passive margins remain poorly understood. Integration of apatite fission track analysis (AFTA) and stratigraphic landscape analysis (SLA) at a number of margins has provided new insights into the development of elevated passive continental margins (EPCMs). In particular, these studies have highlighted the importance of integrating evidence from the preserved rock record with information on the deposition and erosional removal of rock units which are no longer present ("missing section"). From these studies we have formulated nine propositions regarding the formation of EPCMs and the nature of the controlling processes, viz: 1: EPCMs are not the inevitable consequence of rifting and breakup 2: Elevated topography at present-day EPCMs developed long after breakup 3: Similar EPCM landscapes at different margins suggest similar controlling processes 4: EPCMs undergo episodic burial and exhumation rather than slow monotonic denudation, both before rifting and after breakup 5: Post-breakup exhumation at continental margins is not restricted to elevated onshore regions 6: Post-breakup burial and exhumation have affected low lying margins as well as EPCMs 7: Episodic km-scale exhumation and re-burial also affects cratonic regions 8: Exhumation events show a broad level of synchroneity across continents and oceans and correlate with plate boundary events and changes in plate motions. 9: EPCMs are located where there is an abrupt, lateral change in crustal or lithospheric thickness These propositions imply that positive and negative vertical motions at passive margins are controlled by plate-scale processes. Many of these key aspects are absent from current geodynamic models of passive margin development. Understanding the processes that control vertical movements at passive continental margins requires development of realistic geodynamic models that honour these propositions.

  19. Species sensitivity distributions for suspended clays, sediment burial, and grain size change in the marine environment. (United States)

    Smit, Mathijs G D; Holthaus, Karlijn I E; Trannum, Hilde C; Neff, Jerry M; Kjeilen-Eilertsen, Grete; Jak, Robbert G; Singsaas, Ivar; Huijbregts, Mark A J; Hendriks, A Jan


    Assessment of the environmental risk of discharges, containing both chemicals and suspended solids (e.g., drilling discharges to the marine environment), requires an evaluation of the effects of both toxic and nontoxic pollutants. To date, a structured evaluation scheme that can be used for prognostic risk assessments for nontoxic stress is lacking. In the present study we challenge this lack of information by the development of marine species sensitivity distributions (SSDs) for three nontoxic stressors: suspended clays, burial by sediment, and change in sediment grain size. Through a literature study, effect levels were obtained for suspended clays, as well as for burial of biota. Information on the species preference range for median grain size was used to assess the sensitivity of marine species to changes in grain size. The 50% hazardous concentrations (HC50) for suspended barite and bentonite based on 50% effect concentrations (EC50s) were 3,010 and 1,830 mg/L, respectively. For burial the 50% hazardous level (HL50) was 5.4 cm. For change in median grain size, two SSDs were constructed; one for reducing and one for increasing the median grain size. The HL50 for reducing the median grain size was 17.8 mum. For increasing the median grain size this value was 305 mum. The SSDs have been constructed by using information related to offshore oil- and gas-related activities. Nevertheless, the results of the present study may have broader implications. The hypothesis of the present study is that the SSD methodology developed for the evaluation of toxic stress can also be applied to evaluate nontoxic stressors, facilitating the incorporation of nontoxic stressors in prognostic risk assessment tools.

  20. Design and evaluation of a bioreactor with application to forensic burial environments. (United States)

    Dunphy, Melissa A; Weisensee, Katherine E; Mikhailova, Elena A; Harman, Melinda K


    Existing forensic taphonomic methods lack specificity in estimating the postmortem interval (PMI) in the period following active decomposition. New methods, such as the use of citrate concentration in bone, are currently being considered; however, determining the applicability of these methods in differing environmental contexts is challenging. This research aims to design a forensic bioreactor that can account for environmental factors known to impact decomposition, specifically temperature, moisture, physical damage from animals, burial depth, soil pH, and organic matter content. These forensically relevant environmental variables were characterized in a soil science context. The resulting metrics were soil temperature regime, soil moisture regime, slope, texture, soil horizon, cation exchange capacity, soil pH, and organic matter content. Bioreactor chambers were constructed using sterilized thin-walled polystyrene boxes housed in calibrated temperature units. Gravesoil was represented using mineral soil (Ultisols), and organic soil proxy for Histosols, horticulture mix. Gravesoil depth was determined using mineral soil horizons A and Bt2 to simulate surface scatter and shallow grave burial respectively. A total of fourteen different environmental conditions were created and controlled successfully over a 90-day experiment. These results demonstrate successful implementation and control of forensic bioreactor simulating precise environments in a single research location, rather than site-specific testing occurring in different geographic regions. Bone sections were grossly assessed for weathering characteristics, which revealed notable differences related to exposure to different temperature regimes and soil types. Over the short 90-day duration of this experiment, changes in weathering characteristics were more evident across the different temperature regimes rather than the soil types. Using this methodology, bioreactor systems can be created to replicate many

  1. Quasi-100 ky glacial-interglacial cycles triggered by subglacial burial carbon release

    Directory of Open Access Journals (Sweden)

    N. Zeng


    Full Text Available A mechanism is proposed in which climate, carbon cycle and icesheets interact with each other to produce a feedback that can lead to quasi-100 ky glacial-interglacial cycles. A central process is the burial and preservation of organic carbon by icesheets which contributes to the observed glacial-interglacial CO2 change (the glacial burial hypothesis, Zeng, 2003. Allowing carbon cycle to interact with physical climate, here I further hypothesize that deglaciation can be triggered by the ejection of glacial burial carbon when a major icesheet grows to sufficiently large size after a prolonged glaciation so that subglacial transport becomes significant. Glacial inception may be initiated by CO2 drawdown due to a relaxation from a high but transient interglacial CO2 value as the land-originated CO2 invades into deep ocean via thermohaline circulation and CaCO3 compensation. Also important for glacial inception may be the CO2 uptake by vegetation and soil regrowth in the previously ice-covered regions. When tested in a fully coupled Earth system model with comprehensive carbon cycle components and semi-empirical physical climate components, it produced under certain parameter regimes self-sustaining glacial-interglacial cycles with durations of 93 ky, CO2 changes of 90 ppmv, temperature changes of 6°C. Since the 100 ky cycles can not be easily explained by the Milankovitch astronomical forcing alone, this carbon-climate-icesheet mechanism provides a strong feedback that could interact with external forcings to produce the major observed Quaternary climatic variations. It is speculated that some glacial terminations may be triggered by this internal feedback while others by orbital forcing. Some observable consequences are highlighted that may support or falsify the theory.

  2. The geometry and lithology of the Cima Sandstone Lentil: a paleoseep-bearing interbed in the Moreno Formation, central California (United States)

    Wheatley, P. V.; Schwartz, H.


    The Cima Sandstone Lentil outcrops over a relatively small area on the western side of the San Joaquin Valley in central California. Here this unit can be found in the Panoche Hills in the northern portion of the field area and the Tumey Hills in the southern portion of the field area. The Cima Sandstone resides within the 800m Moreno Formation that spans the Maastrichtian to the Danian. The Moreno Formation comprises four members, which are the Dosados Member, the Tierra Loma Member, the Marca Shale Member, and the Dos Palos Shale Member (of which the Cima Sandstone is an interbed). The Cima Sandstone contains numerous large carbonate mounds, concretions, and pavements, indicating paleoseep activity. The Cima Sandstone has never been studied in detail, but recent interest in sandstone injectites as well as interest in paleoseeps has prompted us to examine this interbed more carefully. The Cima is an immature sandstone composed primarily of quartz along with small amounts of micas and feldspars as well as varying amounts of glauconite. These minerals are generally cemented by carbonate but, occasionally, iron oxide cement is present locally. Much variation exists within the Cima Sandstone Lentil and we seek to characterize and understand this variation. One of the most obvious sources of variability is the thickness of the unit itself. The thickness ranges from near 60m in the northern Panoche Hills to only 9m in the Tumey Hills. Induration also varies noticeably, from well cemented in the north, to unconsolidated in the south. Similarly, the sandstone is grain-supported and houses some depositional structures in the northern outcrops but becomes largely matrix-supported and lacking bedding in the southern outcrops. Preliminary data suggests that proximity to carbonate concretions, fluid conduits, and underlying injectites may have some influence over grain size and sorting.

  3. Relationship between karstification and burial dolomitization in Permian platform carbonates (Lower Khuff - Oman) (United States)

    Beckert, Julia; Vandeginste, Veerle; John, Cédric M.


    Large breccia fabrics associated with karst constitute an important structure in massive limestone successions. The dimensions and shapes of breccia structures are controlled by the initial fracture pattern of the limestone and preferential pathways of the karstifying fluids, but subsequently breccia fabrics can also govern the migration of later fluids. Therefore, breccias are highly relevant features to capture for reservoir characterisation. Outcrop analogues for Lower Khuff units in the Middle East present in the Central Oman Mountains reveal brecciated fabrics up to 10s of metres in diameter. These brecciated units are closely associated with dolomite bodies of late diagenetic origin. Based on an integrated set of data, the breccias are interpreted as collapsed karst cavities either formed by meteoric or hypogenic fluids. The exact origin of the fluids could not be constrained due to an overprint by later dolomitizing fluids. Based on the composition of the clasts and matrix in the breccias, two dolomitization events are interpreted to have affected the succession, one prior to (early diagenetic [ED] dolomite) and one after brecciation (late diagenetic [DT2] dolomite). Dolomite of shallow burial origin (ED dolomite) was only observed as clasts within breccia and is much more frequent than late diagenetic (medium to deep burial) dolomite clasts. Thus, the timing of the brecciation and collapse is assumed to postdate shallow burial early diagenetic dolomitization. Late diagenetic replacive dolomite (DT2 dolomite) forms 90% of the matrix in the breccia fabrics with the exception of a small area that was not affected by dolomitization, but is rarely present as clasts. Stable isotope measurements [δ18O: - 2.5‰ to - 6‰ VPDB and δ13C: 2.9‰ to 4.8‰ VPDB] suggest a burial origin for the late diagenetic dolomite potentially with the participation of hydrothermal fluids. The dolomitized matrix indicates a migration of late dolomitizing fluids subsequent to or

  4. The Living Dead: the Uncanny and Nineteenth-Century Moral Panic over Premature Burial

    Directory of Open Access Journals (Sweden)

    Natalia Wójcicka


    Full Text Available The fear of premature burial during the nineteenth century escalated to a phenomenon of moral panic. Fueled by the imperfections of the cardiorespiratory standard of death, which allowed for mistakes in pronouncing a person dead, and by the feeling of the uncanny connected to doubts whether an object – a corpse – is animate or inanimate, the moral panic surfaced in a number of forms, including literature, journalism, but also science and legislation. The present study shows how these forms were both an effect of the panic and, simultaneously, a factor which served to uphold and shape it further.

  5. Phosphorus recycling and burial in Baltic Sea sediments with contrasting redox conditions (United States)

    Slomp, Caroline P.; Mort, Haydon P.; Reed, Dan C.; Jilbert, Tom; Gustafsson, Bo G.


    The Baltic Sea is a classical example of a coastal system that is subject to an increased intensity and spatial extent of hypoxia due to human activities. The expansion of hypoxia since the 1960s is the result of increased inputs of nutrients from land (both from fertilizer and wastewater) and is negatively affecting living conditions for benthic organisms. In addition, the biogeochemical cycling of carbon and nutrients has been significantly altered. Water column studies have shown that the availability of dissolved inorganic phosphorus (DIP) is positively correlated with hypoxia due to release of phosphorus from sediment Fe-oxides and from organic matter upon the transition from oxic to hypoxic conditions. Thus, a large internal source of phosphorus exists in the sediment that largely controls short-term variability in water column DIP concentrations. In this presentation, we focus on results of recent field and modeling work for various parts of the Baltic Sea that confirm the role of Fe-bound P from seasonally hypoxic sediments at intermediate water depths as a major source of DIP. We also show that extended hypoxia and anoxia leads to depletion of sediment Fe-bound P and, ultimately, lower rates of sediment-water exchange of P. Authigenic Ca-P minerals appear to be only a relatively minor burial sink for P. The lack of major inorganic P burial makes the Baltic Sea sensitive to the feedback loop between increased hypoxia, enhanced regeneration of P and increased primary productivity. Historical records of bottom water oxygen at two sites (Bornholm, Northern Gotland) show a decline over the past century which is accompanied by a rise in values of typical sediment proxies for anoxia (total sulfur, molybdenum and organic C/P ratios). While sediment reactive P concentrations in anoxic basins are equal to or higher than at oxic sites, burial rates of P at hypoxic and anoxic sites are up to 20 times lower because of lower sedimentation rates. Nevertheless, burial of

  6. Assessing the potential risks of burial practices on groundwater quality in rural north-central Nigeria. (United States)

    Zume, Joseph T


    Several cultures of north-central Nigeria do not use community cemeteries. Instead, human remains are buried in and around family compounds, often in shallow and sometimes unmarked graves. At several locations, graves and drinking water wells end up too close to be presumed environmentally safe. This paper reports findings of a pilot study that explored the potential for groundwater contamination from gravesites in some rural settlements of north-central Nigeria. Preliminary results suggest that the long-standing burial practices among some cultures of rural north-central Nigeria may potentially compromise groundwater quality, which is, by far, their most important source of drinking water.

  7. Hydrogeology of the 200 Areas low-level burial grounds: An interim report: Volume 2, Appendixes

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Bjornstad, B.N.; Bergeron, M.P.; Wallace, D.W.; Newcomer, D.R.; Schramke, J.A.; Chamness, M.A.; Cline, C.S.; Airhart, S.P.; Wilbur, J.S.


    This report presents information derived form the installation of 35 ground-water monitoring wells around six low-level radioactive/hazardous waste burial grounds located in the 200 Areas of the Hanford Site in southeastern Washington State. This information was collected between May 20, 1987 and August 1, 1988. The contents of this report have been divided into two volumes. Volume 1 contains the main text. This Volume contains the appendixes, including data and supporting information that verify content and results found in the main text.

  8. The Roc de Marsal Neandertal child: a reassessment of its status as a deliberate burial. (United States)

    Sandgathe, Dennis M; Dibble, Harold L; Goldberg, Paul; McPherron, Shannon P


    Whether Neandertals buried their dead has considerable bearing on the debate concerning the nature of their cultural behavior. Among the claims for intentional Neandertal burial in Europe, the child from Roc de Marsal has long been one of the less contentious examples because its articulated skeleton was found in what has become widely accepted as an intentionally excavated pit. However, what is known about the context of the Roc de Marsal remains from the original descriptions, coupled with new stratigraphic, sedimentological, and archaeological data on the site from recent excavations, cast serious doubt on this interpretation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Characterization of 618-11 solid waste burial ground, disposed waste, and description of the waste generating facilities

    Energy Technology Data Exchange (ETDEWEB)

    Hladek, K.L.


    The 618-11 (Wye or 318-11) burial ground received transuranic (TRTJ) and mixed fission solid waste from March 9, 1962, through October 2, 1962. It was then closed for 11 months so additional burial facilities could be added. The burial ground was reopened on September 16, 1963, and continued operating until it was closed permanently on December 31, 1967. The burial ground received wastes from all of the 300 Area radioactive material handling facilities. The purpose of this document is to characterize the 618-11 solid waste burial ground by describing the site, burial practices, the disposed wastes, and the waste generating facilities. This document provides information showing that kilogram quantities of plutonium were disposed to the drum storage units and caissons, making them transuranic (TRU). Also, kilogram quantities of plutonium and other TRU wastes were disposed to the three trenches, which were previously thought to contain non-TRU wastes. The site burial facilities (trenches, caissons, and drum storage units) should be classified as TRU and the site plutonium inventory maintained at five kilograms. Other fissile wastes were also disposed to the site. Additionally, thousands of curies of mixed fission products were also disposed to the trenches, caissons, and drum storage units. Most of the fission products have decayed over several half-lives, and are at more tolerable levels. Of greater concern, because of their release potential, are TRU radionuclides, Pu-238, Pu-240, and Np-237. TRU radionuclides also included slightly enriched 0.95 and 1.25% U-231 from N-Reactor fuel, which add to the fissile content. The 618-11 burial ground is located approximately 100 meters due west of Washington Nuclear Plant No. 2. The burial ground consists of three trenches, approximately 900 feet long, 25 feet deep, and 50 feet wide, running east-west. The trenches constitute 75% of the site area. There are 50 drum storage units (five 55-gallon steel drums welded together

  10. Reservoir Characterization and Tectonic Settings of Ahwaz Sandstone Member of the Asmari Formation in the Zagros Mountain, SW of Iran (United States)

    Adabi, M. H.; Sadeghi, A. D.; Hosseini, M.; Moalemi, A.; Lotfpour, A.; Khatibi Mehr, M.; Salehi, M.; Zohdi, A.; Jafarzadeh, M.


    The Ahwaz Sandstone Member of the Asmari Formation, the major oil reservoir in Zagros mountain, have been studied to understand the distribution, provenance, tectonic setting and reservoir characteristic of Ahwaz Sandstone intervals as an exploration target. This study was based on petrographic and geochemical analysis of 16 core samples from 13 oilfields in the Dezful Embayment zone, and 2 surface sections (Katula and Khami) in Izeh zone. Petrographic studies of 400 thin sections and geochemical analysis indicated that sandstones consist of quartzarenite (Khami surface section), sublitharenite ( Katula surface section) and subarkose (subsurface sections). The modal analysis of medium size and well sorted samples show a recycled orogen (Katula outcrop) and craton (Khami and subsurface sections) tectonic setting. The parent rocks for Ahwaz Sandstone, based on petrographic point counting suggest a low to medium grade metamorphic and plutonic source. Petrographic and grain size analysis indicate a shallow shoreline to barrier bar environments. Heavy minerals in sandstones have mostly plutonic source and abundance of stable heavy mineral, along with well rounded and high sphericity, support stable cratonic source for subsurface sections and Khami surface section. However, in Katula section, heavy minerals have metamorphic source. Facies map illustrated that siliciclastic sediments in Asmari Formation during Rupelian time comes from south-west and north west of the study area. During Chattian, sand distribution reaches to the maximum level and sediments arrived from south-west, north-west and also north-east of the study area. In Aquitanian, sandstones sourced from two areas of south-west and north-west. In Burdigalian stage, sandstone sourced only from south and south-west. These sandstones have limited distributions. Tectonic settings based on geochemical analysis, plotted on discrimination diagrams, suggest that passive continental margin. These sandstones were

  11. Characterization of Bacterial Community Dynamics during the Decomposition of Pig Carcasses in Simulated Soil Burial and Composting Systems. (United States)

    Ki, Bo-Min; Kim, Yu Mi; Jeon, Jun Min; Ryu, Hee Wook; Cho, Kyung-Suk


    Soil burial is the most widely used disposal method for infected pig carcasses, but composting has gained attention as an alternative disposal method because pig carcasses can be decomposed rapidly and safely by composting. To understand the pig carcass decomposition process in soil burial and by composting, pilot-scale test systems that simulated soil burial and composting were designed and constructed in field. The envelope material samples were collected using special sampling devices without disturbance, and bacterial community dynamics were analyzed by high-throughput pyrosequencing for 340 days. Based on the odor gas intensity profiles, it was estimated that the active and advanced decay stages were reached earlier by composting than by soil burial. The dominant bacterial communities in the soil were aerobic and/or facultatively anaerobic gram negative bacteria such as Pseudomonas, Gelidibacter, Mucilaginibacter, and Brevundimonas. However, the dominant bacteria in the composting system were anaerobic, thermophilic, endospore-forming, and/or halophilic gram positive bacteria such as Pelotomaculum, Lentibacillus, Clostridium, and Caldicoprobacter. Different dominant bacteria played important roles in the decomposition of pig carcasses in the soil and compost. This study provides useful comparative date for the degradation of pig carcasses in the soil burial and composting systems.

  12. A new perspective on studying burial environment before archaeological excavation: analyzing bacterial community distribution by high-throughput sequencing. (United States)

    Xu, Jinjin; Wei, Yanfei; Jia, Hanqing; Xiao, Lin; Gong, Decai


    Burial conditions play a crucial role in archaeological heritage preservation. Especially, the microorganisms were considered as the leading causes which incurred degradation and vanishment of historic materials. In this article, we analyzed bacterial diversity and community structure from M1 of Wangshanqiao using 16 S rRNA gene amplicon sequencing. The results indicated that microbial communities in burial conditions were diverse among four different samples. The samples from the robber hole varied most obviously in community structure both in Alpha and Beta diversity. In addition, the dominant phylum in different samples were Proteobacteria, Actinobacteria and Bacteroidetes, respectively. Moreover, the study implied that historical materials preservation conditions had connections with bacterial community distribution. At the genus level, Acinetobacter might possess high ability in degrading organic culture heritage in burial conditions, while Bacteroides were associated closely with favorable preservation conditions. This method contributes to fetch information which would never recover after excavation, and it will help to explore microbial degradation on precious organic culture heritage and further our understanding of archaeological burial environment. The study also indicates that robbery has a serious negative impact on burial remains.

  13. Geophysical monitoring of simulated clandestine graves using electrical and ground-penetrating radar methods: 0-3 years after burial. (United States)

    Pringle, Jamie K; Jervis, John R; Hansen, James D; Jones, Glenda M; Cassidy, Nigel J; Cassella, John P


    This study provides forensic search teams with systematic geophysical monitoring data over simulated clandestine graves for comparison to active cases. Simulated "wrapped" and "naked" burials were created. Multigeophysical surveys were collected over a 3-year monitoring period. Bulk ground resistivity, electrical resistivity imaging, multifrequency ground-penetrating radar (GPR), and grave and background "soil-water" conductivity data were collected. Resistivity surveys revealed the naked burial had consistently low-resistivity anomalies, whereas the wrapped burial had small, varying high-resistivity anomalies. GPR 110- to 900-MHz frequency surveys showed the wrapped burial could be detected throughout, with the "naked" burial mostly resolved. Two hundred and twenty-five megahertz frequency GPR data were optimal. "Soil-water" analyses showed rapidly increasing (year 1), slowly increasing (year 2), and decreasing (year 3) conductivity values. Results suggest resistivity and GPR surveys should be collected if target "wrapping" is unknown, with winter to spring surveys optimal. Resistivity surveys should be collected in clay-rich soils. © 2012 American Academy of Forensic Sciences.

  14. Evidence for hydraulic fracturing at Gale crater, Mars: Implications for burial depth of the Yellowknife Bay formation (United States)

    Caswell, Tess E.; Milliken, Ralph E.


    NASA's Curiosity rover identified a formerly habitable environment within strata informally known as the Yellowknife Bay formation. The stratigraphic relationship, and thus depositional age, of these rocks relative to other geologic units in Gale crater is not clear from orbital data alone. If part of lower Aeolis Mons (informally known as Mount Sharp), the Yellowknife Bay rocks have been deeply buried and exhumed prior to 3.2-3.3 Ga. If part of younger alluvial fan deposits, however, they likely have never experienced more than ∼100 m of burial. Knowledge of burial history can thus constrain the stratigraphic placement of Yellowknife Bay and the habitable environment preserved therein. The mechanics of natural hydraulic fractures observed in mudstone at YKB allow us to evaluate its burial history and imply a minimum burial depth of 1.2 km. This is consistent with burial by the entirety of lower Mount Sharp and a depositional age of ∼ 3.6- 3.8 Ga, providing observation-based evidence that Mount Sharp was once much more laterally extensive than its present form. Rocks of the Yellowknife Bay formation thus represent the oldest strata that Curiosity will encounter during its journey in Gale crater, and any additional habitable environments discovered along Curiosity's future path represent conditions at younger times.

  15. Characterizing Damage Evolution and Yield in Sandstone Under Triaxial Loading as a Function of Changing Effective Pressure (United States)

    Choens, R. C.; Chester, F. M.


    Experimental rock deformation was used to study 1) the accumulation of microscopic damage preceding macroscopic failure across the brittle-ductile transition (BDT) in granular porous rocks, 2) how damage induced at one effective pressure (P) affects failure at a different P, and 3) the appropriateness of single yield envelope versus multiple yield envelope models. Granular porous material is idealized as an elastic-plastic material, where failure occurs by localized dilatant shear at low P and compactant cataclastic flow at high P. Given distinct failure modes in the low and high P regimes, different types of damage may develop prior to failure at different P. As such, yielding of porous rocks has been modeled with a single yield envelope, or with two distinct yield envelopes corresponding to the different failure modes. Water saturated cylinders of Berea sandstone (18% porosity, 185 µm grain size) were deformed in triaxial compression at a shortening rate of 4 µm/s. During each experiment, the confining and pore pressure were held constant; acoustic emissions (AE), axial stress, axial displacement, and pore volume changes were recorded. Samples were deformed at pore pressures of 10, 20, and 30 MPa, and confining pressures of 50, 180, and 260 MPa to investigate the brittle, transitional, and ductile regimes. Three different load paths were used. The first involved loading to failure to establish a baseline response. The second involved initial loading to 80% of the differential stress at failure, unloading, and reloading to failure at a different pore pressure. The third was similar to the second, except confining pressure was changed between load and reload to cause failure in a different regime than the initial load. AE is used to quantify damage evolution, and the Kaiser effect was used to map damage states in stress space. The experiments show that contours of equivalent damage are subparallel to the failure envelope across the BDT, and that macroscopic

  16. Chemical and physical hydrogeology of coal, mixed coal-sandstone and sandstone aquifers from coal-bearing formations in the Alberta Plains region, Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Lemay, T.G. [Alberta Geological Survey, Edmonton, AB (Canada)


    With the decline of conventional oil and gas reserves, natural gas from coal (NGC) is an unconventional gas resource that is receiving much attention from petroleum exploration and development companies in Alberta. Although the volume of the NGC resource is large, there are many challenges facing NGC development in Alberta, including technical and economic issues, land access, water disposal, water diversion and access to information. Exploration and development of NGC in Alberta is relatively new, therefore there is little baseline data on which to base regulatory strategies. Some important information gaps have been filled through water well sampling in coal, mixed coal-sandstone and sandstone aquifers throughout Alberta. Analyses focused on the chemical and physical characteristics aquifers in use for domestic or agricultural purposes. Aquifer depths were generally less than 100 metres. Samples collected from Paskapoo-Scollard Formation, Horseshoe Canyon Formation and Belly River Group aquifers exceed Canadian water quality guideline values with respect to pH, sodium, manganese, chloride, chromium, sulphate, phenols and total dissolved solids. Pump tests conducted within the aquifers indicate that the groundwater flow is complicated. Water quality will have to be carefully managed to ensure responsible disposal practices are followed. Future studies will focus on understanding the chemical and biological process that occur within the aquifers and the possible link between these processes and gas generation. Mitigation and disposal strategies for produced water will also be developed along with exploration strategies using information obtained from hydrogeologic studies. 254 refs., 182 tabs., 100 figs., 3 appendices.

  17. Ground-water quality in the western part of the Cambrian-Ordovician aquifer in the Western Lake Michigan Drainages, Wisconsin and Michigan (United States)

    Saad, D.A.


    Ground-water samples were collected during the summer of 1995 from 29 wells in the western part of the Cambrian-Ordovician aquifer in the Western Lake Michigan Drainages study unit of the National-Water Quality Assessment Program. Analyses of ground-water samples from these wells were used to provide an indication of waterquality conditions in this heavily used part of the aquifer.

  18. Logging identification for the Lower Cambrian Niutitang shale reservoir in the Upper Yangtze region, China: A case study of the Cengong block, Guizhou Province


    Ruyue Wang; Wenlong Ding; Xinyu Wang; Zixian Cui; Xinghua Wang; En Chen; Yaxiong Sun; Zikang Xiao


    Currently, China has achieved a breakthrough in the Lower Silurian Longmaxi shale in Sichuan Basin and its surrounding areas. Compared to the Longmaxi shale, the Lower Cambrian Niutitang shale, which has a greater deposition thickness and wider distribution area, is another significant stratum for China's shale gas. Geophysical well logging is one of the most significant methods used for identification and evaluation of shale gas reservoirs throughout the process of shale gas exploration and ...

  19. Quantifying the effect of squirt flow dispersion from compliant clay porosity in clay bearing sandstones

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne; Fabricius, Ida Lykke


    Compliant porosity in the form of cracks is known to cause significant attenuation and velocity dispersion through pore pressure gradients and consequent relaxation, dubbed squirt flow. Squirt flow from cracks vanish at high confining stress due to crack closing. Studies on clay bearing sandstones......, however, show high attenuation and velocity dispersion remaining at high confining stress. Such dispersion is proposed to be caused by pressure gradients induced by compliant porosity within clay inclusions. By modeling the response of two extreme systems we quantify the possible effects of such clay......-squirt flow on the bulk modulus of a clay bearing sandstone. The predicted magnitude of the clay-squirt effect on the bulk modulus is compared with experimental data. The clay-squirt effect is found to possibly account for a significant portion of the deviances from Gassmann fluid substitution in claybearing...

  20. Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil

    Directory of Open Access Journals (Sweden)

    AS. Martinez

    Full Text Available The present study investigated the distribution and abundance of epibenthic molluscs and their feeding habits associated to substrate features (coverage and rugosity in a sandstone reef system in the Northeast of Brazil. Rugosity, low coral cover and high coverage of zoanthids and fleshy alga were the variables that influenced a low richness and high abundance of a few molluscan species in the reef habitat. The most abundant species were generalist carnivores, probably associated to a lesser offer and variability of resources in this type of reef system, when compared to the coral reefs. The results found in this study could reflect a normal characteristic of the molluscan community distribution in sandstone reefs, with low coral cover, or could indicate a degradation state of this habitat if it is compared to coral reefs, once that the significantly high coverage of fleshy alga has been recognized as a negative indicator of reef ecosystems health.