WorldWideScience

Sample records for usa paleoenvironmental stratigraphic

  1. THE MIDDLE TO UPPER PALEOLITHIC SEQUENCE OF BURAN-KAYA III (CRIMEA, UKRAINE) : NEW STRATIGRAPHIC, PALEOENVIRONMENTAL, AND CHRONOLOGICAL RESULTS

    NARCIS (Netherlands)

    Pean, Stephane; Puaud, Simon; Crepin, Laurent; Prat, Sandrine; Quiles, Anita; van der Plicht, Johannes; Valladas, Helene; Stuart, Anthony J.; Drucker, Dorothee G.; Patou-Mathis, Marylene; Lanoe, Francois; Yanevich, Aleksandr; Hatté, C.; Jull, A.J.T.

    2013-01-01

    Buran-Kaya III is a rockshelter located in Crimea (Ukraine). It provides an exceptional stratigraphic sequence extending from the Middle Paleolithic to the Neolithic. Nine Paleolithic layers have been attributed to the Streletskaya or eastern Szeletian, Micoquian, Aurignacian, Gravettian, and

  2. Paleoenvironmental evolution and geomorphic dynamics recorded in the Homo-bearing Pleistocene stratigraphic succession of Aalat (Eritrea, East Africa): A pedological perspective

    Science.gov (United States)

    Scarciglia, Fabio; Mercatante, Giuseppe; Donato, Paola; Ghinassi, Massimiliano; Carnevale, Giorgio; Delfino, Massimo; Oms, Oriol; Papini, Mauro; Pavia, Marco; Sani, Federico; Rook, Lorenzo

    2017-04-01

    The Aalat stratigraphic succession represents a 300 m-thick continental archive in the northern sector of the African Rift Valley (Dandiero basin, Eritrea). Based on high-resolution magnetostratigraphy, along with tephrostratigrapic, paleontological and paleoanthropological data and correlations, the chronological constraints for the emplacement of this succession can be fixed at two stages characterized by normal polarity of the Earth's magnetic field, i.e. the base of the Jaramillo event and the lower part of the Brunhes chron, marking the Early to Middle Pleistocene transition. Remains of Homo erectus/ergaster and abundant fossil vertebrates were identified. Despite nowadays the study area has a typical arid, hot desert climate, the sedimentary succession records repeated shifts from fluvial to lacustrine facies, in line with dominant mammalian taxa characterized by strong water dependence and ichthyofauna typical of shallow-water fluvio-lacustrine paleoenvironments. The dominance of these water-controlled depositional environments over more than 250 ka suggests a major tectonic control, even though a clear overprinting of Pleistocene climate changes can be detected. The main morphological soil features, along with physico-chemical, mineralogical, geochemical and micromorphological data of selected soil profiles and horizons depict an overall poor to moderate degree of soil development, coherently with high rates of sedimentation of about 1 mm/year and local erosive phases. Nonetheless, the presence of calcic and especially petrocalcic horizons and one petrogypsic horizon at different stratigraphic heights clearly indicates cyclical phases of geomorphic stability, which allowed important leaching and accumulation of carbonate (or gypsum). Their complex, polygenetic fabric, often showing brecciation and re-dissolution features, points to a polyphased genesis, caused by changes in soil moisture conditions over time. This finding, together with the alternation of

  3. U-Pb Geochronology of non-marine Upper Triassic strata of the Colorado Plateau (western North America): implications for stratigraphic correlation and paleoenvironmental reconstruction

    Science.gov (United States)

    Rasmussen, C.; Mundil, R.; Irmis, R. B.; Keller, C. B.; Giesler, D.; Gehrels, G. E.

    2017-12-01

    The Triassic is a critical period in Earth history that witnessed the origin of modern ecosystems and frequent climate fluctuations, as well as major environmental events such as flood basalt volcanism and bolide impacts. The Chinle Formation contains a primary non-marine archive for past ecosystems in North America due to its fossil richness and well-studied sedimentology. Moreover, within these highly fossiliferous strata, a biotic turnover has been reported that has been hypothesized to coincide with one or more of the aforementioned environmental events. Unfortunately, few radioisotopic ages have been published for the Late Triassic, limiting our ability for lithological and paleoenvironmental correlations. In addition, the superposition of the Chinle Formation remains illusive due to frequent lateral facies changes and discontinuous outcrops across the Colorado Plateau. The 520 m long core 1A of the Colorado Plateau Coring Project from Petrified Forest National Park (PFNP) (Arizona) provides, for the first time, a continuous section of these early Mesozoic sedimentary strata. Many of the sand- and siltstones from this continuous succession throughout most of the Upper Triassic Chinle Formation contain euhedral zircons suitable for U-Pb analyses. We analyzed >300 crystals each from 10 samples using LA-ICPMS; these results indicated abundant Late Triassic crystals that appear to be closely associated with the depositional age of the host rock. We then selected the youngest grains from these samples to obtain precise CA-TIMS U-Pb single zircon ages in order to constrain the maximum depositional ages (using quantitative methods) of these formations. We are able to revise the proposed time scale (based on outcrop samples) for Upper Triassic strata at PFNP and evaluate whether the biotic turnover observed within the Sonsela Member of these strata coincides with the Manicouagan bolide impact event. This revised chronostratigraphic framework allows intercalibration

  4. Sedimentary facies analysis of the Mesozoic clastic rocks in Southern Peru (Tacna, 18°S): Towards a paleoenvironmental Redefinition and stratigraphic Reorganization

    Science.gov (United States)

    Alván, Aldo; Jacay, Javier; Caracciolo, Luca; Sánchez, Elvis; Trinidad, Inés

    2018-07-01

    The Mesozoic rocks of southern Peru comprise a Middle Jurassic to Early Cretaceous sedimentary sequence deposited during a time interval of approximately 34 Myr. In Tacna, these rocks are detrital and constitute the Yura Group (Callovian to Tithonian) and the Hualhuani Formation (Berriasian). Basing on robust interpretation of facies and petrographic analysis, we reconstruct the depositional settings of such units and provide a refined stratigraphic framework. Accordingly, nine types of sedimentary facies and six architectural elements are defined. They preserve the record of a progradational fluvial system, in which two styless regulated the dispersion of sediments: (i) a high-to moderate-sinuosity meandering setting (Yura Group), and a later (ii) incipient braided setting (Hualhuani Formation). The Yura Group (Callovian-Tithonian) represents the onset of floodplain deposits and lateral accretion of point-bar deposits sited on a semi-flat topography. Nonetheless, the progradational sequence was affected by at least two rapid marine ingressions occurred during Middle Callovian and Tithonian times. Such marine ingressions reveal the proximity of a shallow marine setting and incipient carbonate deposition. In response to increase in topographic gradient, the Hualhuani Formation (Berriasian) deposited as extensive multistory sandy channels. The mineralogy of the Mesozoic sediments suggests sediment supplies and intense recycling from a craton interior (i.e. Amazon Craton and/or plutonic sources) located eastward of the study area.

  5. A 31,000 year record of paleoenvironmental and lake-level change from Harding Lake, Alaska, USA

    Science.gov (United States)

    Finkenbinder, Matthew S.; Abbott, Mark B.; Edwards, Mary E.; Langdon, Catherine T.; Steinman, Byron A.; Finney, Bruce P.

    2014-03-01

    Physical and geochemical proxy analyses of sediment cores from Harding Lake in central Alaska are used to reconstruct paleoenvironmental change and millennial scale fluctuations in lake level for the last ˜31,000 years. We analyzed a composite 422 cm core from the lake depocenter (42.1 m water depth) and identified 4 distinct lithologic units based on variability in dry bulk density, organic matter, biogenic silica, carbon to nitrogen mass ratios (C/N), organic matter carbon isotopes (δ13C), pollen, and elemental abundances via scanning X-ray fluorescence, with age control provided by 16 Accelerator Mass Spectrometry radiocarbon dates and 210Pb dating. In addition, we analyzed a transect of cores from 7.1 m, 10.75 m, 15.91 m, and 38.05 m water depths to identify lake level fluctuations and to characterize sediment compositional changes as a function of water depth. Organic matter content and magnetic susceptibility values in surface sediments from all transect cores show a strong correlation with water depth. Interpretation of four lithologic units with well-dated contacts produced a record of water-depth variations that is consistent with independent climate records from eastern Beringia. Basal coarse-grained sediments (quartz pebble diamicton) were deposited prior to 30,700 calendar years before present (yr BP), possibly from fluvial reworking or deflation during a period of severe aridity. Unit 1 sediments were deposited between 30,700 and 15,700 yr BP and are characterized by a low organic matter content, a high magnetic susceptibility, and low biogenic silica concentrations resulting from very low lake levels, low terrestrial and in-lake productivity and a high flux of clastic sediment. An abrupt increase in organic matter and biogenic silica concentration marks the transition into Unit 2 sediments, which were deposited between 15,700 and 9,400 yr BP when lake levels were higher and variable (relative to Unit 1). The transition to full interglacial

  6. Stratigraphic architecture of back-filled incised-valley systems: Pennsylvanian-Permian lower Cutler beds, Utah, USA

    Science.gov (United States)

    Wakefield, Oliver J. W.; Mountney, Nigel P.

    2013-12-01

    The Pennsylvanian to Permian lower Cutler beds collectively form the lowermost stratigraphic unit of the Cutler Group in the Paradox Basin, southeast Utah. The lower Cutler beds represent a tripartite succession comprising lithofacies assemblages of aeolian, fluvial and shallow-marine origin, in near equal proportion. The succession results from a series of transgressive-regressive cycles, driven by repeated episodes of climatic variation and linked changes in relative sea-level. Relative sea-level changes created a number of incised-valleys, each forming through fluvial incision during lowered base-level. Aeolian dominance during periods of relative sea-level lowstand aids incised-valley identification as the erosive bounding surface juxtaposes incised-valley infill against stacked aeolian faces. Relative sea-level rises resulted in back-flooding of the incised-valleys and their infill via shallow-marine and estuarine processes. Back-flooded valleys generated marine embayments within which additional local accommodation was exploited. Back-filling is characterised by a distinctive suite of lithofacies arranged into a lowermost, basal fill of fluvial channel and floodplain architectural elements, passing upwards into barform elements with indicators of tidal influence, including inclined heterolithic strata and reactivation surfaces. The incised-valley fills are capped by laterally extensive and continuous marine limestone elements that record the drowning of the valleys and, ultimately, flooding and accumulation across surrounding interfluves (transgressive surface). Limestone elements are characterised by an open-marine fauna and represent the preserved expression of maximum transgression.

  7. End-Pleistocene to Holocene paleoenvironmental record from piston corer samples and the challenge of stratigraphic correlation of playa sediment data with a connected alluvial apron from Damghan Basin, Iran

    Science.gov (United States)

    Büdel, Christian; Hoelzmann, Philipp; Wennrich, Volker; Majid Padashi, Sajed; Baumhauer, Roland

    2015-04-01

    three meters are made up by homogenous partly laminated deposits, rich auf clay and silt and with a decreased content of sulphur and halite. Regular Peaks of sulfate and calcium within this unit presumably indicate post-sedimentary precipitation of gypsum. The homogenous sediment unit is followed by layers clearly set up in three major phases of up-fining sediments. Higher Al and Mg contents following this sedimentation phases suggest a considerable amount of syn-sedimentary clay mineral enrichment. The alignment of alluvial fan phases and phases recorded in the playa is challenging. As figured out before, the focused signals in the study are linked to non-local factors affecting supra-regional land surface alteration. But 0 to less than 1 % organic carbon contents decrease the chance of deriving a valid sediment dating and the possibility of chrono-stratigraphic correlation. Anyway, the clear transitional zone from halite dominated to more or less halite-free sediments can serve as a guideline to the development of further correlations.

  8. The evolution of a subaqueous delta in the Anthropocene: A stratigraphic investigation of the Brazos River delta, TX USA

    Science.gov (United States)

    Carlin, Joseph A.; Dellapenna, Timothy M.

    2015-12-01

    Globally, deltas are increasingly threatened by anthropogenic activities. As a result, deltas now evolve through the combined effects of natural and human-induced processes occurring throughout the fluvial-deltaic system. The Brazos River delta, located along the Texas coast in the northwestern Gulf of Mexico, and its watershed have been impacted by direct and indirect human activities since the late 19th century. This provides an opportunity to investigate how such alterations have shaped the evolution of a delta in the Anthropocene, a time when humans are drivers of geological change. Historic alteration to the delta and watershed include extensive agricultural activity, jetty construction at the mouth in the late 1890s, mouth diversion ~10 km to the southwest in 1929, and reservoir construction throughout the early and mid 20th Century. Three subaerial deltaic geometries provided the framework to connect subaerial deltaic responses, to the anthropogenic alterations, to the resulting stratigraphic characteristics observed in the subaqueous delta. This study utilized high-resolution geophysical data (swath bathymetry, side scan sonar, CHIRP subbottom profiling) on the subaqueous delta to investigate the subaqueous delta stratigraphy and infer the processes that shaped the deltaic record over time. The results showed distinct areas across the subaqueous delta that were dominated by erosion and deposition. Erosional areas corresponded to earlier growth phase depocenters being exposed at the surface, while the depositional areas corresponded to areas with the most recent growth phase depocenter overlying the earlier depocenters. These results highlight that the subaqueous depocenter has migrated westward over time, consistent with the observed changes to the subaerial delta. Additionally, the data showed that evidence for these past growth phases and depocenters may be preserved within the subaqueous delta, even after subaerial portions of the delta returned to pre

  9. Uniquely Acquired Vintage Seismic Reflection Data Reveal the Stratigraphic and Tectonic History of the Montana Disturbed Belt, USA

    Science.gov (United States)

    Speece, M. A.; Link, C. A.; Stickney, M.

    2011-12-01

    In 1983 and 1984 Techco of Denver, Colorado, acquired approximately 302 linear kilometers of two-dimensional (2D) seismic reflection data in Flathead and Lake Counties, Montana, USA, as part of an initiative to identify potential drilling targets beneath the Swan and Whitefish Mountain Ranges and adjacent basins of northwestern Montana. These seismic lines were collected in the Montana Disturbed Belt (MDB) or Montana thrust belt along the western edge of Glacier National Park in mountainous terrain with complicated subsurface structures including thrust faults and folds. These structures formed during the Laramide Orogeny as sedimentary rocks of the Precambrian Belt Supergroup were thrust eastward. Later, during the Cenozoic, high-angle normal faults produced prominent west-facing mountain scarps of the Mission, Swan and Whitefish mountains. The 1983 data set consisted of two profiles of 24-fold (96-channels) Vibroseis data and four profiles of 24-fold (96-channels) helicopter-assisted dynamite data. The dynamite data were collected using the Poulter Method in which explosives were placed on poles and air shots were recorded. The 1983 dynamite profiles extend from southwest to northeast across the Whitefish Mountain Range to the edge of Glacier National Park and the Vibroseis data were collected along nearby roadways. The 1984 data set consists of four profiles of 30-fold (120-channels) helicopter-assisted dynamite data that were also collected using the Poulter Method. The 1984 profiles cross the Swan Mountain Range between Flathead Lake and Glacier National Park. All of these data sets were recently donated to Montana Tech and subsequently recovered from nine-track tape. Conventionally processed seismic stacked sections from the 1980s of these data show evidence of a basement decollement that separates relatively undeformed basement from overlying structures of the MDB. Unfortunately, these data sets have not been processed using modern seismic processing

  10. On the importance of stratigraphic control for vertebrate fossil sites in Channel Islands National Park, California, USA: Examples from new Mammuthus finds on San Miguel Island

    Science.gov (United States)

    Pigati, Jeffery S.; Muhs, Daniel R.; McGeehin, John P.

    2016-01-01

    Quaternary vertebrate fossils, most notably mammoth remains, are relatively common on the northern Channel Islands of California. Well-preserved cranial, dental, and appendicular elements of Mammuthus exilis (pygmy mammoth) and Mammuthus columbi (Columbian mammoth) have been recovered from hundreds of localities on the islands during the past half-century or more. Despite this paleontological wealth, the geologic context of the fossils is described in the published literature only briefly or not at all, which has hampered the interpretation of associated 14C ages and reconstruction of past environmental conditions. We recently discovered a partial tusk, several large bones, and a tooth enamel plate (all likely mammoth) at two sites on the northwest flank of San Miguel Island, California. At both localities, we documented the stratigraphic context of the fossils, described the host sediments in detail, and collected charcoal and terrestrial gastropod shells for radiocarbon dating. The resulting 14C ages indicate that the mammoths were present on San Miguel Island between ∼20 and 17 ka as well as between ∼14 and 13 ka (thousands of calibrated 14C years before present), similar to other mammoth sites on San Miguel, Santa Cruz, and Santa Rosa Islands. In addition to documenting the geologic context and ages of the fossils, we present a series of protocols for documenting and reporting geologic and stratigraphic information at fossil sites on the California Channel Islands in general, and in Channel Islands National Park in particular, so that pertinent information is collected prior to excavation of vertebrate materials, thus maximizing their scientific value.

  11. Great Basin paleoenvironmental studies project

    International Nuclear Information System (INIS)

    1993-01-01

    Project goals, project tasks, progress on tasks, and problems encountered are described and discussed for each of the studies that make up the Great Basin Paleoenvironmental Studies Project for Yucca Mountain. These studies are: Paleobotany, Paleofauna, Geomorphology, and Transportation. Budget summaries are also given for each of the studies and for the overall project

  12. USA

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    http://www.systime.dk/ungdomsuddannelser/almen-studieforberedelse/usa-en-grundbog-i-politik-og-okonomi.html......http://www.systime.dk/ungdomsuddannelser/almen-studieforberedelse/usa-en-grundbog-i-politik-og-okonomi.html...

  13. Sequence stratigraphic and sedimentologic significance of biogenic structures from a late Paleozoic marginal- to open-marine reservoir, Morrow Sandstone, subsurface of southwest Kansas, USA

    Science.gov (United States)

    Buatois, L.A.; Mangano, M.G.; Alissa, A.; Carr, T.R.

    2002-01-01

    Integrated ichnologic, sedimentologic, and stratigraphic studies of cores and well logs from Lower Pennsylvanian oil and gas reservoirs (lower Morrow Sandstone, southwest Kansas) allow distinction between fluvio-estuarine and open marine deposits in the Gentzler and Arroyo fields. The fluvio-estuarine facies assemblage is composed of both interfluve and valley-fill deposits, encompassing a variety of depositional environments such as fluvial channel, interfluve paleosol, bay head delta, estuary bay, restricted tidal flat, intertidal channel, and estuary mouth. Deposition in a brackish-water estuarine valley is supported by the presence of a low diversity, opportunistic, impoverished marine ichnofaunal assemblage dominated by infaunal structures, representing an example of a mixed, depauperate Cruziana and Skolithos ichnofacies. Overall distribution of ichnofossils along the estuarine valley was mainly controlled by the salinity gradient, with other parameters, such as oxygenation, substrate and energy, acting at a more local scale. The lower Morrow estuarine system displays the classical tripartite division of wave-dominated estuaries (i.e. seaward-marine sand plug, fine-grained central bay, and sandy landward zone), but tidal action is also recorded. The estuarine valley displays a northwest-southeast trend, draining to the open sea in the southeast. Recognition of valley-fill sandstones in the lower Morrow has implications for reservoir characterization. While the open marine model predicts a "layer-cake" style of facies distribution as a consequence of strandline shoreline progradation, identification of valley-fill sequences points to more compartmentalized reservoirs, due to the heterogeneity created by valley incision and subsequent infill. The open-marine facies assemblage comprises upper, middle, and lower shoreface; offshore transition; offshore; and shelf deposits. In contrast to the estuarine assemblage, open marine ichnofaunas are characterized by a

  14. Stratigraphic response across a structurally dynamic shelf: The latest guadalupian composite sequence at Walnut Canyon, New Mexico, U.S.A

    Science.gov (United States)

    Rush, J.; Kerans, C.

    2010-01-01

    The uppermost Yates and Tansill formations (Late Permian), as exposed along Walnut Canyon in Carlsbad Caverns National Park, New Mexico, USA, provide a unique opportunity to document the depositional architecture of a progradational, oversteepened, and mechanically failure-prone carbonate platform. Detailed facies mapping permitted critical assessment of depositional processes operating along this structurally dynamic platform margin. At the shelf crest, thick (12 m), vertically stacked fenestral-pisolite-tepee complexes indicate a stable shoreline. Early lithification of sediments and extensive cementation fostered rapid vertical accretion and allowed the shelf crest to easily adjust to base-level oscillations by stepping landward, stepping seaward, or aggrading. This production imbalance-in combination with syndepositional brittle failure and down-to-the-basin tilting(architecture, fracture properties, and a highly refined fusulinid biostratigraphic framework. Where fractures tip out, down-to-the-basin rotation is often observed with concurrent seaward thickening of overlying beds, indicating that such fractures functioned as a syndepositional hinge. A facies disjunction and horizontally juxtaposed fusulinid zonation were documented across an 80?? seaward-dipping dilational fracture filled with polymict breccia. An overlying damage zone consisting of spar-cemented fractures nested within silt-filled fractures illustrates periodic reactivation. Field relationships indicate that the dilational fracture approximates a paleoescarpment that resulted from catastrophic failure of the Capitan platform margin. Younger strata onlapped the paleoescarpment and gradually filled the reentrant. This mechanically compromised paleoescarpment was subsequently reactivated during the latest Guadalupian lowstand and was subaerially filled by siliciclastics and polymict breccia derived from the platform top. Results from Walnut Canyon indicate that shelf crest aggradation dominantly

  15. Iowa Stratigraphic Data Points

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — The Iowa stratigraphic column consists of rock materials of varying geologic age that have been categorized into a shapefile for summarizing the 3 dimensional aspect...

  16. Some debatable problems of stratigraphic classification

    Science.gov (United States)

    Gladenkov, Yury

    2014-05-01

    . Lithostratigraphy may be regarded as the start of geological mapping on scales of 1 : 10 000, 1 : 25 000 or 1 : 50 000, and lithostratigraphic subdivisions can be used as the mapping units because they practically have isochronic boundaries when we deal with geological mapping on these scales. 5. Russian geologists interpret a chronozone (defined with due account of the standard assemblage-zone) as a part of a stage. In opinion of other specialists, zones serve as correction markers. This gives rise to controversy where zonal scales are needed for the Phanerozoic or whether stage scales are sufficient. In the Russian Code a chronozone is referred to general stratigraphic units (less than a stage). 6. The popular GSSP "concept" may be is inadequate in the broad sense because stages remain "empty" and do not reflect geological events. The search of "golden spikes" can be useful as a part of comprehensive investigations of stratigraphic subdivisions. "Silver" and other type spike-markers can be used as well as recommended by event stratigraphy (Ager, 1973). 7. A new version of "International Stratigraphic Guide" should include not only recommendations but also alternative views. However the work must not be done in a hurry! In avoid bias representatives of interested countries should be involved. Finally, I would like to make two proposals. Proposal 1. A special symposium should be held during the second International Congress on Stratigraphy-2015 to review national stratigraphic codes (USA, Germany, Great Britain, China, Russia, Australia and other countries). This can provide better understanding of their similarities and dissimilarities and enable to realize how much they differ from each other. The review may show the present state of the stratigraphic classification and reveal both pressing and alleged problems of stratigraphy of the early XXI century. Proposal 2. It would be appropriate to prepare a special publication presenting briefly codes of different countries. Every

  17. The Yapeyu paleosurface : stratigraphific and paleoenvironmental signified in the evolution of superior cretaceous of Uruguay

    International Nuclear Information System (INIS)

    Pazos, P.; Tofalo, M.; Gonzalez

    1998-01-01

    The named Yapeyu paleosurface placed between Yapeyu and del Palacio Members of the Asencio Formations is anlalyzed in outcrops of the Pedro Chico, Gruta del Palacio and Cca. Arroyo Coquimbo localities. Herrein, its morphologic and paleoenvironmental features are considered to attribute an paleosoil origin for this. This paleosurface is indicative of an important break in the sedimentation and contain several indicators of paleoclimatic tropical and humid conditions. Following allostratigraphic schemes, the paleosurface represent the lower contact of the Asencio Formation constituting a new stratigraphic proposal. Finally, taking into account sedimentalogical features the alluvial origin by the conglomerates of del Palacio Member is rejected. (author)

  18. Palynological and paleoenvironmental studies of the Gombe ...

    African Journals Online (AJOL)

    Palynological and paleoenvironmental studies of the Gombe Formation Gongola Basin, Nigeria. OJ Ojo, SO Akande. Abstract. No Abstract Available Journal of Mining and Geology Vol.40(2) 2004: 143-149. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  19. Characteristics, stratigraphic architecture, and time framework of multi-order mixed siliciclastic and carbonate depositional sequences, outcropping Cisco Group (Late Pennsylvanian and Early Permian), Eastern Shelf, north-central Texas, USA

    Science.gov (United States)

    Yang, Wan; Kominz, Michelle A.

    2003-01-01

    The Cisco Group on the Eastern Shelf of the Midland Basin is composed of fluvial, deltaic, shelf, shelf-margin, and slope-to-basin carbonate and siliciclastic rocks. Sedimentologic and stratigraphic analyses of 181 meter-to-decimeter-scale depositional sequences exposed in the up-dip shelf indicated that the siliciclastic and carbonate parasequences in the transgressive systems tracts (TST) are thin and upward deepening, whereas those in highstand systems tracts (HST) are thick and upward shallowing. The sequences can be subdivided into five types on the basis of principal lithofacies, and exhibit variable magnitude of facies shift corresponding to variable extents of marine transgression and regression on the shelf. The sequence stacking patterns and their regional persistence suggest a three-level sequence hierarchy controlled by eustasy, whereas local and regional changes in lithology, thickness, and sequence type, magnitude, and absence were controlled by interplay of eustasy, differential shelf subsidence, depositional topography, and pattern of siliciclastic supply. The outcropping Cisco Group is highly incomplete with an estimated 6-11% stratigraphic completeness. The average duration of deposition of the major (third-order) sequences is estimated as 67-102 ka on the up-dip shelf and increases down dip, while the average duration of the major sequence boundaries (SB) is estimated as 831-1066 ka and decreases down dip. The nondepositional and erosional hiatus on the up-dip shelf was represented by lowstand deltaic systems in the basin and slope.

  20. Vertebrate paleontology, stratigraphy, and paleohydrology of Tule Springs Fossil Beds National Monument, Nevada (USA)

    Science.gov (United States)

    Springer, Kathleen; Pigati, Jeffery S.; Scott, Eric

    2017-01-01

    Tule Springs Fossil Beds National Monument (TUSK) preserves 22,650 acres of the upper Las Vegas Wash in the northern Las Vegas Valley (Nevada, USA). TUSK is home to extensive and stratigraphically complex groundwater discharge (GWD) deposits, called the Las Vegas Formation, which represent springs and desert wetlands that covered much of the valley during the late Quaternary. The GWD deposits record hydrologic changes that occurred here in a dynamic and temporally congruent response to abrupt climatic oscillations over the last ~300 ka (thousands of years). The deposits also entomb the Tule Springs Local Fauna (TSLF), one of the most significant late Pleistocene (Rancholabrean) vertebrate assemblages in the American Southwest. The TSLF is both prolific and diverse, and includes a large mammal assemblage dominated by Mammuthus columbi and Camelops hesternus. Two (and possibly three) distinct species of Equus, two species of Bison, Panthera atrox, Smilodon fatalis, Canis dirus, Megalonyx jeffersonii, and Nothrotheriops shastensis are also present, and newly recognized faunal components include micromammals, amphibians, snakes, and birds. Invertebrates, plant macrofossils, and pollen also occur in the deposits and provide important and complementary paleoenvironmental information. This field compendium highlights the faunal assemblage in the classic stratigraphic sequences of the Las Vegas Formation within TUSK, emphasizes the significant hydrologic changes that occurred in the area during the recent geologic past, and examines the subsequent and repeated effect of rapid climate change on the local desert wetland ecosystem.

  1. Paleo-Environmental Reconstruction Using Ancient DNA

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Winther

    The aim of this thesis has been to investigate and expand the methodology and applicability for using ancient DNA deposited in lake sediments to detect and determine its genetic sources for paleo-environmental reconstruction. The aim was furthermore to put this tool into an applicable context...... solving other scientifically interesting questions. Still in its childhood, ancient environmental DNA research has a large potential for still developing, improving and discovering its possibilities and limitations in different environments and for identifying various organisms, both in terms...... research on ancient and modern environmental DNA (Paper 1), secondly by setting up a comparative study (Paper 2) to investigate how an ancient plant DNA (mini)-barcode can reflect other traditional methods (e.g. pollen and macrofossils) for reconstructing floristic history. In prolongation of the results...

  2. Morphodynamics and stratigraphic architecture of shelf-edge deltas subject to constant vs. dynamic environmental forcings

    Science.gov (United States)

    Straub, K. M.

    2017-12-01

    When deltas dock at the edge of continental margins they generally construct thick stratigraphic intervals and activate channelized continental slope systems. Deposits of shelf-edge deltas have the capacity to store detailed paleo-environmental records, given their location in the source to sink system. However, present day highstand sea-level conditions have pushed most deltaic systems well inbound of their shelf-edges, making it difficult to study their space-time dynamics and resulting stratigraphic products. Several competing theories describe how deltas and their downslope environments respond to sea-level cycles of varying magnitude and periodicity. We explore these hypotheses in a physical experiment where the topographic evolution of a coupled delta and downdip slope system was monitored at high temporal and spatial resolution. The experiment had three stages. In the first stage a delta aggraded at the shelf-edge under constant water and sediment supply, in addition to a constant generation of accommodation through a sea-level rise. In the second stage the sediment transport system responded to low magnitude and high frequency sea-level cycles. Finally, in the third stage the transport system responded to a high magnitude and long period sea-level cycle. In each stage, fine sediment from the input grain size distribution and dissolved salt in the input water supply promoted plunging hyperpycnal flows. Specifically, we compare the mean and temporal variability of the sediment delivered to the slope system between stages. In addition, we compare stratigraphic architecture and sediment sizes delivered to the slope system in each stage. These results are used to improve inversion of slope deposits for paleo-environmental forcings.

  3. Calibrating water depths of Ordovician communities: lithological and ecological controls on depositional gradients in Upper Ordovician strata of southern Ohio and north-central Kentucky, USA

    Directory of Open Access Journals (Sweden)

    Carlton E. Brett

    2015-02-01

    Full Text Available Limestone and shale facies of the Upper Ordovician Grant Lake Formation (Katian: Cincinnatian, Maysvillian are well exposed in the Cincinnati Arch region of southern Ohio and north-central Kentucky, USA. These rocks record a gradual change in lithofacies and biofacies along a gently northward-sloping ramp. This gradient spans very shallow, olive-gray, platy, laminated dolostones with sparse ostracodes in the south to offshore, nodular, phosphatic, brachiopod-rich limestones and marls in the north. This study uses facies analysis in outcrop to determine paleoenvironmental parameters, particularly those related to water depth (e.g., position of the photic zone and shoreline, relative degree of environmental energy. Within a tightly correlated stratigraphic interval (the Mount Auburn and Straight Creek members of the Grant Lake Formation and the Terrill Member of the Ashlock Formation, we document the occurrence of paleoenvironmental indicators, including desiccation cracks and light-depth indicators, such as red and green algal fossils and oncolites. This permitted recognition of a ramp with an average gradient of 10–20 cm water depth per horizontal kilometer. Thus, shallow subtidal (“lagoonal” deposits in the upramp portion fall within the 1.5–6 m depth range, cross-bedded grainstones representing shoal-type environments fall within the 6–18 m depth range and subtidal, shell-rich deposits in the downramp portion fall within the 20–30 m depth range. These estimates match interpretations of depth independently derived from faunal and sedimentologic evidence that previously suggested a gentle ramp gradient and contribute to ongoing and future high-resolution paleontologic and stratigraphic studies of the Cincinnati Arch region.

  4. Uncertainty management in stratigraphic well correlation and stratigraphic architectures: A training-based method

    Science.gov (United States)

    Edwards, Jonathan; Lallier, Florent; Caumon, Guillaume; Carpentier, Cédric

    2018-02-01

    We discuss the sampling and the volumetric impact of stratigraphic correlation uncertainties in basins and reservoirs. From an input set of wells, we evaluate the probability for two stratigraphic units to be associated using an analog stratigraphic model. In the presence of multiple wells, this method sequentially updates a stratigraphic column defining the stratigraphic layering for each possible set of realizations. The resulting correlations are then used to create stratigraphic grids in three dimensions. We apply this method on a set of synthetic wells sampling a forward stratigraphic model built with Dionisos. To perform cross-validation of the method, we introduce a distance comparing the relative geological time of two models for each geographic position, and we compare the models in terms of volumes. Results show the ability of the method to automatically generate stratigraphic correlation scenarios, and also highlight some challenges when sampling stratigraphic uncertainties from multiple wells.

  5. Stratigraphic implications of uranium deposits

    International Nuclear Information System (INIS)

    Langford, F.F.

    1980-01-01

    One of the most consistent characteristics of economic uranium deposits is their restricted stratigraphic distribution. Uraninite deposited with direct igneous affiliation contains thorium, whereas chemical precipitates in sedimentary rocks are characterized by thorium-free primary uranium minerals with vanadium and selenium. In marine sediments, these minerals form low-grade disseminations; but in terrestrial sediments, chiefly fluvial sandstones, the concentration of uranium varies widely, with the high-grade portions constituting ore. Pitchblende vein deposits not only exhibit the same chemical characteristics as the Colorado-type sandstone deposits, but they have a stratigraphically consistent position at unconformities covered by fluvial sandstones. If deposits in such diverse situations have critical features in common, they are likely to have had many features of their origin in common. Thus, vein deposits in Saskatchewan and Australia may have analogues in areas that contain Colorado-type sandstone deposits. In New Mexico, the presence of continental sandstones with peneconformable uranium deposits should also indicate good prospecting ground for unconformity-type vein deposits. All unconformities within the periods of continental deposition ranging from Permian to Cretaceous should have uranium potential. Some situations, such as the onlap of the Abo Formation onto Precambrian basement in the Zuni Mountains, may be directly comparable to Saskatchewan deposition. However, uranium occurrences in the upper part of the Entrada Sandstone suggest that unconformities underlain by sedimentary rocks may also be exploration targets

  6. Sedimentologic and paleontologic study of the southeast coast of Buenos Aires province, Argentina: A late Pleistocene Holocene paleoenvironmental reconstruction

    Science.gov (United States)

    Aramayo, S. A.; Téllez, B. Gutiérrez; Schillizzi, R. A.

    2005-10-01

    A paleoenvironmental reconstruction of the southeast coast of Buenos Aires province, Argentina, is made mainly on the basis of paleontological and paleoichnological studies, supported by sedimentological analyses and radiocarbon dating. Continental late Pleistocene and continental, transitional, and marine Holocene stratigraphic units are identified. The former comprises fossil mammals and ichnites of 16000-12,000 BP. The continental early Holocene time, ca. 8100 BP, is represented by an interdune paleoenvironment in which shallow brackish ponds were colonized by diatoms, fish, rodents, and birds. A transitional paleoenvironment in the middle Holocene—6930-6570 BP—is recorded by deposits formed by estuarine crabs. During the late Holocene, between 5000 and 4800 BP, a marine transgression was recorded by a rich mollusc fauna.

  7. Geomorphologic, stratigraphic and sedimentologic evidences of ...

    Indian Academy of Sciences (India)

    The EPF particularly has acted significantly and influenced in evolving the geomorphological landscape and the stratigraphic architecture of the area. The block bounded by the two faults has earlier been considered as a single entity, constituting a half-graben. The present investigation (by morpho-stratigraphic and ...

  8. The PRISM3D paleoenvironmental reconstruction

    Science.gov (United States)

    Dowsett, H.; Robinson, M.; Haywood, A.M.; Salzmann, U.; Hill, Daniel; Sohl, L.E.; Chandler, M.; Williams, Mark; Foley, K.; Stoll, D.K.

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additional geographic sites and environmental parameters, and is continuously refined by independent research findings. The new PRISM three dimensional (3D) reconstruction differs from previous PRISM reconstructions in that it includes a subsurface ocean temperature reconstruction, integrates geochemical sea surface temperature proxies to supplement the faunal-based temperature estimates, and uses numerical models for the first time to augment fossil data. Here we describe the components of PRISM3D and describe new findings specific to the new reconstruction. Highlights of the new PRISM3D reconstruction include removal of Hudson Bay and the Great Lakes and creation of open waterways in locations where the current bedrock elevation is less than 25m above modern sea level, due to the removal of the West Antarctic Ice Sheet and the reduction of the East Antarctic Ice Sheet. The mid-Piacenzian oceans were characterized by a reduced east-west temperature gradient in the equatorial Pacific, but PRISM3D data do not imply permanent El Niño conditions. The reduced equator-to-pole temperature gradient that characterized previous PRISM reconstructions is supported by significant displacement of vegetation belts toward the poles, is extended into the Arctic Ocean, and is confirmed by multiple proxies in PRISM3D. Arctic warmth coupled with increased dryness suggests the formation of warm and salty paleo North Atlantic Deep Water (NADW) and a more vigorous thermohaline circulation system that may

  9. Biogeochemistry of selenium isotopes: processes, cycling and paleoenvironmental applications

    NARCIS (Netherlands)

    Mitchell, K.A.

    2012-01-01

    Selenium (Se) is an essential trace element, which, with multiple oxidation states and six stable isotopes, has been suggested as a potentially powerful environmental tracer and paleoenvironmental proxy. Chapter 1 provides a literature review of the Se cycle. While the Se cycle shares some

  10. Paleocene stratigraphic plays in Uruguay offshore

    International Nuclear Information System (INIS)

    Morales, E; Soto, M; Ferro, S; Tomasini, J; De Santa Ana, H; Conti, B.; Veroslavsky, G.

    2012-01-01

    The Uruguayan continental margin offshore evolution is represented by three large mega sequences: pre rift, rift and post rift, which are correlated with other South Atlantic basins. The tectonic and stratigraphic knowledge about the Uruguayan offshore evolution enable a hydrocarbon potential approximation . The mapping of the seismic depositional sequences are covered by deep basins. The methodology used identify the migration of Uruguayan side depo centers such as the stratigraphic plays group in particular a prospective Paleocene sequence

  11. Glaciotectonic deformation and reinterpretation of the Worth Point stratigraphic sequence: Banks Island, NT, Canada

    Science.gov (United States)

    Vaughan, Jessica M.; England, John H.; Evans, David J. A.

    2014-05-01

    capping till. The investigation of the Worth Point stratigraphic sequence provides the first detailed description of the internal architecture of a polydeformed hill-hole pair, and as such provides an insight into the formation and evolution of an enigmatic landform. Notably, the stratigraphic sequence documents ice-marginal and subglacial glaciotectonics in permafrost terrain, as well as regional glacial and relative sea level histories. The reinterpreted stratigraphy fundamentally rejects the long-established paleoenvironmental history of Worth Point that assumed a simple ‘layer-cake’ stratigraphy including the type-site for an organically rich, preglacial interval (Worth Point Fm).

  12. PALEOENVIRONMENTAL EVOLUTION OF THE ITARARÉ GROUP (PARANÁ BASIN IN THE REGIONS OF SALTO AND ITU, EAST OF SÃO PAULO STATE, BRAZIL

    Directory of Open Access Journals (Sweden)

    Sérgio Bergamaschi

    2016-03-01

    Full Text Available Itararé Group represents the glacial record of Gondwana Continent in the intracratonic Paraná Basin, encompassing regions of Southern Brazil, Eastern Paraguay, Northeast Argentina and Northern Paraguay. Itararé Group is the thickest sedimentary package of Paraná Basin, and was deposited over 36 million years during the end of the Carboniferous and the beginning of the Permian. However, in relation to its paleoenvironmental evolution, it is generally understood that more research is necessary, in order to better understand the genesis of the Itararé Group in different places. The present work entailed mapping facies associations for the Itararé Group in the city of Salto, in São Paulo State, by identifying and classifying sedimentary facies that, in turn, were utilized to develop a paleoenvironmental evolution model. This model was based on geological mapping carried out over 125 km². Petrological and petrographic descriptions of 32 outcrops of Itararé Group also were studied. These results were compared with subsurface data obtained by Sistema de Informações de Águas Subterrâneas, Serviços Geológicos do Brasil (SIAGAS-CPRM; System Water Information Groundwater, Geological Survey of Brazil. Through lithofacies and petrographic analyses and making a comparison between five column sections, surface and subsurface data, a stratigraphic correlation model was established for the region. Through this model was possible to identify four facies associations, which, together, indicate how the paleoenvironmental evolution of the region occurred. The first three associations (A, B, C were interpreted as being formed in subaqueous environment, being related to sandy lobe systems, followed by the last association (D, pertaining to a fluvial system.

  13. Characteristics of the gravel size and potassium in the Ejin Alluvial Fan from remote sensing images and stratigraphic section

    International Nuclear Information System (INIS)

    Zhang, Lu; Guo, Huadong; Wang, Qinjun

    2014-01-01

    The Ejin Alluvial Fan (EAF), located in the north-west of China, is an important recorder of both paleoclimatic and tectonic information of the north margin of the Qinghai-Tibet Plateau. Remote sensing technics, including optical and microwave sensors, have been the key spatial observation tools to extract the surface information related to the paleoenvironment. In this paper, the gravel size and chemical element potassium K distributions of the EAF were obtained from RadarSat-2 Synthetic Aperture Radar (SAR) data and LandSat TM optical data, respectively. In addition, the stratigraphic section of the EAF was established and the corresponding geological information in the vertical direction with different periods was obtained. Combining the geological survey information and surface distribution information, it can be concluded as follows. 1) The EAF covers an area of above 30,000 km 2 and may be the largest arid and semi-arid alluvial fan in the world based on the remote sensing survey. 2) Some surface parameters which are related to the paleoenvironmental change can be obtained from remote sensing data, such as the gravel size and potassium K parameters. 3) The forming process of the EAF and the corresponding environments will be understood deeply, combining the paleoenvironmental related parameters derived from remote sensing data and the geologic survey data

  14. Biological and Geochemical Development of Placer Gold Deposits at Rich Hill, Arizona, USA

    Directory of Open Access Journals (Sweden)

    Erik B. Melchiorre

    2018-02-01

    Full Text Available Placer gold from the Devils Nest deposits at Rich Hill, Arizona, USA, was studied using a range of micro-analytical and microbiological techniques to assess if differences in (paleo-environmental conditions of three stratigraphically-adjacent placer units are recorded by the gold particles themselves. High-angle basin and range faulting at 5–17 Ma produced a shallow basin that preserved three placer units. The stratigraphically-oldest unit is thin gold-rich gravel within bedrock gravity traps, hosting elongated and flattened placer gold particles coated with manganese-, iron-, barium- (Mn-Fe-Ba oxide crusts. These crusts host abundant nano-particulate and microcrystalline secondary gold, as well as thick biomats. Gold surfaces display unusual plumate-dendritic structures of putative secondary gold. A new micro-aerophilic Betaproteobacterium, identified as a strain of Comamonas testosteroni, was isolated from these biomats. Significantly, this ‘black’ placer gold is the radiogenically youngest of the gold from the three placer units. The middle unit has well-rounded gold nuggets with deep chemical weathering rims, which likely recorded chemical weathering during a wetter period in Arizona’s history. Biomats, nano-particulate gold and secondary gold growths were not observed here. The uppermost unit is a pulse placer deposited by debris flows during a recent drier period. Deep cracks and pits in the rough and angular gold from this unit host biomats and nano-particulate gold. During this late arid period, and continuing to the present, microbial communities established within the wet, oxygen-poor bedrock traps of the lowermost placer unit, which resulted in biological modification of placer gold chemistry, and production of Mn-Fe-Ba oxide biomats, which have coated and cemented both gold and sediments. Similarly, deep cracks and pits in gold from the uppermost unit provided a moist and sheltered micro-environment for additional gold

  15. Micropaleontologic record of Quaternary paleoenvironments in the Central Albemarle Embayment, North Carolina, U.S.A.

    Science.gov (United States)

    Culver, Stephen J.; Farrell, Kathleen M.; Mallinson, David J.; Willard, Debra A.; Horton, Benjamin P.; Riggs, Stanley R.; Thieler, E. Robert; Wehmiller, John F.; Parham, Peter; Snyder, Scott W.; Hillier, Caroline

    2011-01-01

    To understand the temporal and spatial variation of eustatic sea-level fluctuations, glacio-hydro-isostacy, tectonics, subsidence, geologic environments and sedimentation patterns for the Quaternary of a passive continental margin, a nearly complete stratigraphic record that is fully integrated with a three dimensional chronostratigraphic framework, and paleoenvironmental information are necessary. The Albemarle Embayment, a Cenozoic regional depositional basin in eastern North Carolina located on the southeast Atlantic coast of the USA, is an ideal setting to unravel these dynamic, interrelated processes.Micropaleontological data, coupled with sedimentologic, chronostratigraphic and seismic data provide the bases for detailed interpretations of paleoenvironmental evolution and paleoclimates in the 90. m thick Quaternary record of the Albemarle Embayment. The data presented here come from a transect of cores drilled through a barrier island complex in the central Albemarle Embayment. This area sits in a ramp-like setting between late Pleistocene incised valleys.The data document the episodic infilling of the Albemarle Embayment throughout the Quaternary as a series of transgressive-regressive (T-R) cycles, characterized by inner shelf, midshelf, and shoreface assemblages, that overlie remnants of fluvial to estuarine valley-fill. Barrier island and marginal marine deposits have a low preservation potential. Inner to mid-shelf deposits of the early Pleistocene are overlain by similar middle Pleistocene shelf sediments in the south of the study area but entirely by inner shelf deposits in the north. Late Pleistocene marine sediments are of inner shelf origin and Holocene deposits are marginal marine in nature. Pleistocene marine sediments are incised, particularly in the northern half of the embayment by lowstand paleovalleys, partly filled by fluvial/floodplain deposits and in some cases, overlain by remnants of transgressive estuarine sediments. The shallowing

  16. The southernmost record of a large erethizontid rodent (Hystricomorpha: Erethizontoidea) in the Pleistocene of South America: Biogeographic and paleoenvironmental implications

    Science.gov (United States)

    Vezzosi, Raúl I.; Kerber, Leonardo

    2018-03-01

    The South American porcupines (Erethizontidae) are included in two genera: Chaetomys and Coendou. The latter is a very speciose taxon, with about 13 living species. During at least the late Pliocene-early Pleistocene, erethizontids immigrated to Central and North America during the Great American Biotic Interchange. Although some Pleistocene fossils have been reported, the Quaternary history of this clade is still understudied. The only known extinct species is Coendou magnus. In this work, a fossil of a porcupine is reported from an Upper Pleistocene fluvial sedimentary sequence cropping out in the Northern Pampa geomorphological region, Santa Fe Province, Argentina. Despite this group having different living forms widely distributed in South American Neotropical woodland habitats, the Pleistocene occurrences of Erethizontidae are scarce and limited to Upper Pleistocene deposits from Bolivia, Brazil, and Uruguay. Currently, the specimen here reported represents the only Pleistocene porcupine from Argentina with a stratigraphical context. The morphological characters as well as the dimensions indicate that it is close to the Pleistocene erethizontid Coendou magnus. In this context, the presence of this erethizontid in such a southern locality, together with other taxa recorded from this site and the associated geological and paleoenvironmental evidence, indicates subtropical conditions, compared with the current conditions, which may have allowed a southern displacement of taxa more related to woodlands and xeric subtropical environments.

  17. Paleoenvironmental conditions in the late Paleogene, Sumatra, Indonesia

    Science.gov (United States)

    O'shea, Natalie; Arthur Bettis, E.; Zaim, Yahdi; Rizal, Yan; Aswan, Aswan; Gunnell, Gregg F.; Zonneveld, John-Paul; Ciochon, Russell L.

    2015-11-01

    A stratified paleosol sequence exposed in an open pit mine in central Sumatra provides a record of the paleoenvironmental conditions in the lower reaches of a large river system in the late Paleogene (latest Eocene or Oligocene). Morphological, geochemical, and stable isotope data suggest that the sequence represents a mosaic of local environmental conditions changing from estuarine to riverine up section. Weakly expressed soils formed on low-lying estuary surfaces, while more well expressed soils formed on higher, better drained surfaces. Peatlands (coal) with clayey subsoils were along the estuary margins. Well-expressed soils with evidence of clay translocation and chemical weathering become more common higher in the section where alluvial deposits associated with a meandering river are dominant. Stable carbon isotope ratios support a paleolandscape dominated by C3 plants with input by C4 vegetation limited to a few intervals. Finally, whole-rock geochemistry suggests moderate chemical weathering consistent with a tropical locality. This multi-proxy paleoenvironmental reconstruction suggests a highly productive lowland forest environment at this locality in the late Paleogene and provides the first direct examination of the terrestrial environment in Sumatra at this time. The limited fossil record in Island Southeast Asia during this time period is likely a result of poor bone and shell preservation in tropical forest environments combined with a general lack of systematic prospecting. However, our continuing work in this area has produced a relatively diverse assemblage of fossil vertebrates, now including fishes, amphibians, turtles, crocodiles, and mammals, as well as a growing diversity of fossil plants.

  18. Paleoenvironmental assessment of recent environmental changes in Florida Bay, USA: a biomarker based study

    Science.gov (United States)

    Xu, Y.; Holmes, C.W.; Jaffe, R.

    2007-01-01

    The extractable lipid compositions in four Florida Bay cores were determined in order to understand environmental changes over the last 160 years. The most significant environmental change was recorded by oscillations in the amplitude and frequency of biomarkers during the 20th century. Two seagrass molecular proxies (Paq and the C25/C27n-alkan-2-one ratio) reached a maximum post 1900, suggesting that abundant seagrass communities existed during the 20th century. A sharp drop in the Paq value from 0.65 to 0.48 in the central Bay at about 1987 seems to reflect seagrass die-off. The concentrations of microbial biomarkers (C20 HBIs, C25 HBIs and dinosterol) substantially increased after 1950 in the TC, BA and NB cores, reflecting an increase in algal (planktonic organism) primary productivity. However, the RB core presented the highest abundance of C25 HBIs and dinosterol during the period of 1880–1940, suggesting historically large inputs from diatoms and dinoflagellates. A substantial rise in abundance of taraxerol (a specific biomarker of mangroves) from 20 μg/g TOC in the 1830s to 279 μg/g TOC in the l980s is likely a result of increased mangrove primary productivity along the shore of the NE Bay. These changes are most likely the result of hydrological alterations in South Florida.

  19. Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex

    Science.gov (United States)

    Vogel, Sebastian; Märker, Michael

    2010-05-01

    SSP1.4 Understanding mixed siliciclastic-volcaniclastic depositional systems and their relationships with geodynamics or GD2.3/CL4.14/GM5.8/MPRG22/SSP3.5 Reconstruction of ancient continents: Dating and characterization of paleosurfaces Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex Sebastian Vogel[1] & Michael Märker[1] [1] Heidelberg Academy of Sciences and Humanities c/o University of Tübingen, Rümelinstraße 19-23, D-72070 Tübingen, Germany. Within the geoarchaeological research project "Reconstruction of the Ancient Cultural Landscape of the Sarno River Plain" undertaken by the German Archaeological Institute in cooperation with the Heidelberg Academy of Sciences and Humanities/University of Tübingen a methodology was developed to model the spatial dispersion of volcanic deposits of Somma-Vesuvius volcanic complex since its Plinian eruption AD 79. Eventually, this was done to reconstruct the paleo-topography and paleo-environment of the Sarno River plain before the eruption AD 79. We collected, localized and digitized more than 1,800 core drillings to gain a representative network of stratigraphical information covering the entire plain. Besides other stratigraphical data including the characteristics of the pre-AD 79 stratum, the depth to the pre-AD 79 paleo-surface was identified from the available drilling documentation. Instead of applying a simple interpolation of the drilling data, we reconstructed the pre-AD 79 paleo-surface with a sophisticated geostatistical methodology using a machine based learning approach based on classification and regression trees. We hypothesize that the present-day topography reflects the ancient topography, because the eruption of AD 79 coated the ancient topography, leaving ancient physiographic elements of the Sarno River plain still recognizable in the present-day topography. Therefore, a high resolution

  20. Paleoenvironmental Evolution of Continental Carbonates in West-Central Brazil

    Directory of Open Access Journals (Sweden)

    EMILIANO C. OLIVEIRA

    Full Text Available ABSTRACT This paper presents a sedimentological and stratigraphical study of Quaternary (Middle to Late Pleistocene/Holocene continental carbonates outcrops inside Pantanal Basin and its surroundings, especially in Serra da Bodoquena, Pantanal do Miranda and Corumbá/Ladário plateau, in the state of Mato Grosso do Sul, as well as in Serra das Araras, in the state of Mato Grosso. The aim is to understand the depositional paleoenvironments and analyse climate and tectonic influences in their genesis and evolution. The results show that the deposition of these continental carbonates started in the Middle to Late Pleistocene and have continued, with some interruptions, until the present days. Sedimentary successions were identified in the different areas, without complete correlation. Two sedimentary successions separated by an erosional surface were described in Serra da Bodoquena and Serra das Araras. In Corumbá and Pantanal do Miranda, only one succession was described. These successions were deposited in elongated lakes parallel to fault planes; small lakes, related plains and plateaus; springs related to cliffs produced by faulting; rivers conditioned by topographic variation. The climatic interpretation, without proper temporal resolution, obtained by the stable-isotope composition and stratigraphic interpretation, indicates alternation of dry and wet periods. The Neoproterozoic faults with their neotectonics and the subsidence of the Pantanal Basin, are the major control for carbonated water flow and development of depositional areas, gradually turning plateaus into slight tilted areas, allowing the evolution of depositional systems from lakes to rivers.

  1. Reconstructing ancient river dynamics from the stratigraphic record: can lessons from the past inform our future?

    Science.gov (United States)

    Hajek, E. A.; Chamberlin, E.; Baisden, T.

    2014-12-01

    The richness of the deep-time record and its potential for revealing important characteristics of ancient fluvial landscapes has been demonstrated time and again, including compelling examples of rivers altering their behavior in response to changes in vegetation patterns or abrupt shifts in water and sediment discharge. At present, reconstructions of ancient river and floodplain dynamics are commonly qualitative, and when quantitative metrics are used, it is often for comparison among ancient deposits. Without being able to reconstruct, more comprehensively, important aspects of ancient river and floodplains dynamics, this information has only anecdotal relevance for evaluating and managing present-day landscapes. While methods for reconstructing hydrodynamic and morphodynamic aspects of ancient rivers and floodplains are useful, uncertainties associated with these snapshots complicate the ability to translate observations from geologic to engineering scales, thereby limiting the utility of insight from Earth's past in decision-making and development of sustainable landscape-management practices for modern fluvial landscapes. Here, we explore the degree to which paleomorphodynamic reconstructions from ancient channel and floodplain deposits can be used to make specific, quantitative inferences about ancient river dynamics. We compare a suite of paleoenvironmental measurements from a variety of ancient fluvial deposits (including reconstructions of paleoflow depth, paleoslope, paleo-channel mobility, the caliber of paleo-sediment load, and paleo-floodplain heterogeneity) in an effort to evaluate sampling and empirical uncertainties associated with these methods and identify promising avenues for developing more detailed landscape reconstructions. This work is aimed at helping to develop strategies for extracting practicable information from the stratigraphic record that is relevant for sustainably managing and predicting changes in today's environments.

  2. Economics of Developing Hot Stratigraphic Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  3. Dynamics of living phytoplankton: Implications for paleoenvironmental reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, A B [Centre for Marine and Environmental Research (CIMA), Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)], E-mail: abarbosa@ualg.pt

    2009-01-01

    Phytoplankton is the dominant primary producer in aquatic ecosystems and is considered a gauge of ecological condition and change. Some phytoplankton groups, namely diatoms, dinoflagellates, and coccolithophores, produce morphological or chemical fossils that can be used for paleoenvironmental reconstruction. This study aims to review the processes that regulate dynamics in living phytoplankton and to highlight how this knowledge is used in paleoecological studies. The distribution patterns of phytoplankton in present-day aquatic ecosystems are shaped by the interplay between processes that regulate cell growth and cell death. Cell growth and cell death are regulated by the internal environment of phytoplankton (e.g., specific environmental tolerances, resource uptake properties, cell size, density and morphology, alternative nutritional strategies such as mixotrophy or N{sub 2} uptake, motility, intracellular storage capacities, grazing resistance properties), and by its external environment. The external environment includes variables dependent on the availability of resources (e.g., light intensity, concentration of CO{sub 2} and dissolved inorganic macronutrients and micronutrients, availability of living prey in case of mixotrophs) and variables independent of resources (e.g., temperature, salinity, turbulence, ultraviolet radiation, bioactive compounds, activity of grazers, viruses, and eukaryotic parasites). The importance of recently described loss processes, such as grazing by phagotrophic protists, viral lyses, and programmed cell death, is discussed in the context of its potential impact upon phytoplankton vertical fluxes. Examples of the use of different phytoplankton metrics (e.g. abundance, species composition, species morphology, and elemental composition) to infer contemporaneous as well as past environmental and ecological conditions are critically evaluated.

  4. Dynamics of living phytoplankton: Implications for paleoenvironmental reconstructions

    International Nuclear Information System (INIS)

    Barbosa, A B

    2009-01-01

    Phytoplankton is the dominant primary producer in aquatic ecosystems and is considered a gauge of ecological condition and change. Some phytoplankton groups, namely diatoms, dinoflagellates, and coccolithophores, produce morphological or chemical fossils that can be used for paleoenvironmental reconstruction. This study aims to review the processes that regulate dynamics in living phytoplankton and to highlight how this knowledge is used in paleoecological studies. The distribution patterns of phytoplankton in present-day aquatic ecosystems are shaped by the interplay between processes that regulate cell growth and cell death. Cell growth and cell death are regulated by the internal environment of phytoplankton (e.g., specific environmental tolerances, resource uptake properties, cell size, density and morphology, alternative nutritional strategies such as mixotrophy or N 2 uptake, motility, intracellular storage capacities, grazing resistance properties), and by its external environment. The external environment includes variables dependent on the availability of resources (e.g., light intensity, concentration of CO 2 and dissolved inorganic macronutrients and micronutrients, availability of living prey in case of mixotrophs) and variables independent of resources (e.g., temperature, salinity, turbulence, ultraviolet radiation, bioactive compounds, activity of grazers, viruses, and eukaryotic parasites). The importance of recently described loss processes, such as grazing by phagotrophic protists, viral lyses, and programmed cell death, is discussed in the context of its potential impact upon phytoplankton vertical fluxes. Examples of the use of different phytoplankton metrics (e.g. abundance, species composition, species morphology, and elemental composition) to infer contemporaneous as well as past environmental and ecological conditions are critically evaluated.

  5. Paleoenvironmental Implications of Clay Minerals at Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    Bristow, Thomas F.; Blake, David F.

    2014-01-01

    The Mars Science Laboratory (MSL) Rover, Curiosity spent approx 150 sols at Yellowknife Bay (YKB) studying a section of fluvio-lacustrine sedimentary rocks (with potential indications of volcanic influence), informally known as the Yellowknife Bay formation. YKB lies in a distal region of the Peace Vallis alluvial fan, which extends from the northern rim of Gale Crater toward the dune field at the base of Mt Sharp. Sedimentological and stratigraphic observations are consistent with the Yellowknife Bay formation being part of a distal fan deposit, which could be as young as middle Hesperian to even early Amazonian in age (approx. 3.5 to 2.5 Ga). The Yellowknife Bay formation hosts a unit of mudstone called the Sheepbed member. Curiosity obtained powdered rock samples from two drill holes in the Sheepbed Member, named John Klein and Cumberland, and delivered them to instruments in Curiosity. Data from CheMin, a combined X-ray diffraction (XRD)/X-ray fluorescence instrument (XRF), has allowed detailed mineralogical analysis of mudstone powders revealing a clay mineral component of approx. 20 wt.% in each sample. The clay minerals are important indicators of paleoenvironmental conditions and sensitive recorders of post-depositional alteration processes. The XRD pattern of John Klein reveals a 02l band consistent with a trioctahedral phyllosilicate. A broad peak at approx. 10A with a slight inflexion at approx. 12A indicates the presence of 2:1 type clay minerals in the John Klein sample. The trioctahedral nature of the clay minerals, breadth of the basal reflection, and presence of a minor component with larger basal spacing suggests that John Klein contains a trioctahedral smectite (probably saponite), whose interlayer is largely collapsed because of the low-humidity conditions. The XRD patterns show no evidence of corrensite (mixed-layer chlorite/smectite) or chlorite, which are typical diagenetic products of trioctahedral smectites when subjected to burial and

  6. Litho-stratigraphic and Hydrogeological Evaluation of Groundwater ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2015-10-30

    ://www.ajol.info/index.php/jasem http://www.bioline.org.br/ja. Litho-stratigraphic and Hydrogeological Evaluation of Groundwater System in Parts of. Benin Metropolis, Benin City Nigeria: The Key to Groundwater Sustainability.

  7. The stratigraphic filter and bias in measurement of geologic rates

    Science.gov (United States)

    Schumer, Rina; Jerolmack, Douglas; McElroy, Brandon

    2011-01-01

    Erosion and deposition rates estimated from the stratigraphic record frequently exhibit a power-law dependence on measurement interval. This dependence can result from a power-law distribution of stratigraphic hiatuses. By representing the stratigraphic filter as a stochastic process called a reverse ascending ladder, we describe a likely origin of power-law hiatuses, and thus, rate scaling. While power-law hiatuses in certain environments can be a direct result of power-law periods of stasis (no deposition or erosion), they are more generally the result of randomness in surface fluctuations irrespective of mean subsidence or uplift. Autocorrelation in fluctuations can make hiatuses more or less heavy-tailed, but still exhibit power-law characteristics. In addition we show that by passing stratigraphic data backward through the filter, certain statistics of surface kinematics from their formative environments can be inferred.

  8. Sub-annual paleoenvironmental information evaluated from intensity variations of fluorescent annual layers in a stalagmite from Ryuo-do Cave, Nagasaki Prefecture, western Japan

    Science.gov (United States)

    Sasaki, Hana; Onishi, Yuri; Ishihara, Yoshiro; Yoshimura, Kazuhisa

    2017-04-01

    Stalagmites can provide various types of paleoenvironmental information such as information on vegetation and climate changes. Fluorescent annual layers formed by humic substances (mainly fulvic acids: FA) in these stalagmites can also provide a time proxy, and a time series on precipitation. Fluorescence intensity patterns in these annual layers can be classified into symmetric, gradually increasing and gradually decreasing types. Onishi et al. (EGU2016) demonstrated the existence of these fluorescence intensity patterns in the annual layers, and their stratigraphic changes, by numerical simulations, and suggested that the patterns could provide paleoenvironmental information at a sub-annual resolution. In this study, we carried out an analysis of fluorescence intensity patterns in the annual layers of a stalagmite from Ryuo-do Cave, Nagasaki Prefecture, western Japan, and also simulated the patterns in the stalagmite, to obtain paleoenvironmental information. Fluorescence intensity patterns in the annual layers are strongly affected by annual variations in FA concentration and precipitation rates of calcite. As the result of simulations of fluorescence intensity patterns, cumulative variations and various types of pattern are reproduced. These differences are depending on time lags between the variation of the FA concentration in the drip waters, and that of the growth rate of the stalagmite. Co-precipitation models of FA are divided into the "Hiatus model" in which FA are preferentially preserved in the stalagmite when its growth rate is relatively low, and the "Partition coefficient (PC) model" in which FA concentrations in the stalagmite increase when the calcite precipitation rate is relatively high. However, various fluorescence intensity patterns in the annual layers could be formed under a combination or either of both of the models. Fluorescence intensity patterns in an annual layer in the stalagmite from Ryuo-do Cave, Nagasaki Prefecture, western Japan

  9. Paleoclimatic and paleoenvironmental reconstruction for middle and late holocene in Uruguay southeastern New contributions

    International Nuclear Information System (INIS)

    Del Puerto, L.; Bracco, R.; Inda, H.; Garcia, F.; Panario, D.; Castineira, C.; Capdepont, I.

    2012-01-01

    This work is about the study carried out within the framework of the environmental evolution and the prehistoric human occupation on coastal lagoons in the east of Uruguay. The analysis of the sediments in the zone enable the reconstruction of the Holocene climate history as well as the construction of the Paleoclimatic and paleoenvironmental model belong to the middle and late Holocene

  10. Paleoenvironmental and paleoclimatic investigations on Isla de los Estados, Argentina

    Science.gov (United States)

    Björck, S.; Fernandez, M.; Hjort, C.; Ljung, K.; Martinez, O.; Möller, P.; Ponce, F.; Rabassa, J.; Roig, F.; Unkel, I.; Wohlfarth, B.

    2007-05-01

    The expedition in November-December 2005 to Isla de los Estados (Staten Island) off the southeastern tip of South America was a cooperative venture between Lund University (LU) and Stockholm University (SU) in Sweden and the CADIC-CONICET Institute in Ushuaia, Argentina. The aim of the expedition was threefold: (1) to extend the Swedish paleoclimatic "ATLANTIS"-project (Greenland, Iceland, Faroe Islands, Azores, Grenada, Tristan da Cunha; PI S Björck) to the southern part of the South American continent, (2) to connect earlier glacial and climate history reconstructions from the Antarctic Peninsula to equivalents north of the Drake Passage in southernmost South America, and (3) to complement paleo-information available from the Tierra del Fuego mainland with information from Isla de los Estados. Focus was on two areas in the northern and north-western part of the island, Bahía Colnett and Bahia Crossley. Detailed geomorphologic and stratigraphic mapping of glacial deposits were combined with sampling sediments for OSL dating. To reconstruct the paleoclimatic development of Isla de los Estados since the last ice retreat, four main peat bog/lake sites were cored and sampled. In addition, living trees of Nothofagus and old logs preserved in the peat were sampled for dendrochronological and dendroclimatological studies. Preliminary results show that the deglaciation of the study area occurred before 16500 cal yr BP. Detailed multi- proxy analyses of the four sequences are under way and first results will be presented.

  11. Stratigraphic distribution, taphonomy and paleoenvironments of Spinicaudata in the Triassic and Jurassic of the Paraná Basin

    Science.gov (United States)

    Jenisch, Alan Gregory; Lehn, Ilana; Gallego, Oscar Florencio; Monferran, Mateo Daniel; Horodyski, Rodrigo Scalise; Faccini, Ubiratan Ferrucio

    2017-12-01

    Due to the chitino-phosphatic nature of Spinicaudata conchostracan exoskeletons, their carapaces exhibit a low preservational potential compared to other bivalve groups. However, the recent studies point towards the increased tolerance of the carapace against the physical processes. Due to this peculiar characteristic, conchostracan carapace have been utilized as precise temporal markers in estimating stratigraphic and taphonomic parameters. The same characteristic also makes the spinicaudatans useful in evaluating the depositional processes and environments. The present work aims at providing a paleoenvironmental and stratigraphic analysis of conchostracans (Spinicaudata) from the Triassic-Jurassic of the Paraná Basin (Santa Maria and Caturrita formations) in terms of the sedimentary facies analysis, depositional system characterization, and analysis of the taphonomic signatures of the fossiliferous horizons within these formations. The results from the taphonomic study delineates the presence of 4 distinct fossil assemblages based on the causative mechanism and fundamental characteristics of the fossil concentrations: two taphonomic assemblages in the laminated mudstone beds deposited from the decanting fine-grained sediments in floodplains; the sandstone beds with plane parallel laminations and dune- and ripple-cross-stratifications deposited from the flooding-related overflow in the floodplains; and the association of laminated mudstone and massive sandstone beds deposited as the river mouth bars. The results show that the taphonomic signatures, e.g., closed valves, may indicate the various patterns of autochthony and allochthony. In the fine-grained floodplain assemblages, the high degree of preservation can be attributed to autochthony in the conchostracans, whereas the preservational condition of floodplain sandstone sheet and mouth bar assemblages point toward parautochthony and even allochthony. Therefore, the preservational quality of conchostracan

  12. Paleoenvironmental conditions and strontium isotope stratigraphy in the Paleogene Gafsa Basin (Tunisia) deduced from geochemical analyses of phosphatic fossils

    Science.gov (United States)

    Kocsis, László; Ounis, Anouar; Chaabani, Fredj; Salah, Neili Mohamed

    2013-06-01

    Fossil shark teeth and coprolites from three major phosphorite occurrences in the Gafsa Basin (southwestern Tunisia) were investigated for their geochemical compositions to improve local stratigraphy and to better assess paleoenvironmental conditions. 87Sr/86Sr isotope ratios of shark teeth from the Early Maastrichtian El Haria Formation and from the Early Eocene Métlaoui s.s. Formation yielded Sr isotope ages of 68 ± 1 and 47.9 ± 1.3 Ma, respectively, which accord with the expected stratigraphic positions of these sediments. Conversely, shark teeth from the Paleocene-Eocene Chouabine Formation have large variation in Sr isotope ratios even within individual layers. After statistical treatment and then elimination of certain outlier samples, three age-models are proposed and discussed. The most reasonable solution includes three subsequent Sr ages of 61.8 ± 2.2 Ma, 57.2 ± 1.8 and 54.6 ± 1.6 for layer IX, layers VIII-V and layers IV-0, respectively. Three scenarios are discussed for explanation of the presence of the outliers: (1) diagenesis, (2) re-working and (3) locally controlled seawater Sr isotope ratio. The most plausible account for the higher 87Sr/86Sr ratios relative to the global ocean in some fossils is enhanced intrabasinal re-working due to low sea level. Conversely, the sample with lower 87Sr/86Sr than the global seawater may link to diagenesis or to seawater influenced by weathering of Late Cretaceous marine carbonates, which latter is supported by model calculation as well. The ɛNd values of these fossils are very similar to those reported for Paleogene and Late Cretaceous Tethyan seawater and are compatible with the above interpretations. The relatively low oxygen isotope values in shark teeth from the topmost phosphate bed of the Chouabine Formation, together with the Sr isotope results, point toward recovering better connections with the open sea. These δ18O data reflect elevated ambient temperature, which may link to the Early Eocene

  13. Preservation of Plant Biomolecules and the Relevance to the Interpretation of Paleoenvironmental Signals: Tertiary Metasequoia Fossils as Examples

    Science.gov (United States)

    Yang, H.; Leng, Q.

    2004-12-01

    The degradation and preservation of biomolecules in plant tissues not only affects the inference on paleoecology of ancient plants but also bears significance in the interpretation of paleoenvironmental signals. Using a combined SEM and geochemical approach, we are able to show the source, liability, and preservation of structural biopolymers from morphologically well-preserved Metasequoia tissues from three Tertiary deposits. We detected a continuum of biomolecular preservation in this evolutionarily-conserved conifer. Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) was applied to solvent-extracted residues from both fossil leaf and wood remains in comparison with tissues from their living counterparts. The late Paleocene-early Eocene leaves from Ellesmere Island, Canadian Arctic Archipelago, exhibit the best quality of biochemical preservation and show pyrolysis products derived from labile biomolecules characterized by large amounts of polysaccharides. These labile biomolecules are the oldest record of these kinds so far characterized by the pyrolysis technology. The middle Eocene leaf tissues from Axel Heiberg Island, Canadian Arctic Archipelago, yielded slightly lesser amounts of polysaccharide moieties, but the lignin products are similar to those identified from the Ellesmere Island fossils. Compared with these Arctic materials, the Metasequoia leaves from Miocene Clarkia, Idaho, USA, show the lowest quality of molecular preservation, characterized by a dramatic reduction of polysaccharides. This continuum of relative quality of biomolecular preservation is further confirmed by SEM observations of transverse sections of these fossil leaves. The investigation revealed tissue-specific degradation, and our data support the in-situ polymerization hypothesis for the origin of long-chain homologous pairs of aliphatic n-alk-1-enes/n-alkanes as leaf alteration products. The preferential degradation and selective removal of polysaccharides may be

  14. PaleoGeo: a Web based GIS database for paleoenvironmental studies

    Science.gov (United States)

    Song, Wonsuh; Kondo, Yasuhisa; Oguchi, Takashi

    2014-05-01

    Paleoenvironmental studies cover various fields such as paleohydrology, geomorphology, paleooceanology, paleobiology, paleoclimatology, and chronology. It is difficult for an individual researcher to collect and compile enormous data regarding these fields. We have been compiling portal data and presenting them using a web-based geographical information system (Web-GIS) called PaleoGeo for the multidisciplinary project 'Replacement of Neanderthals by Modern Humans'. The aim of the project is to reconstruct the distribution of Neanderthals and modern humans in time and space in relation to past climate change. We have been collecting information from almost three thousand articles of 13 journals regarding paleoenvironmental research (i.e., Boreas, Catena, Climatic Change, Earth Surface Processes and Landforms, Geomorphology, Journal of Quaternary Science, Palaeogeography, Palaeoclimatology, and Palaeoecology, Quaternary International, Quaternary Research, Quaternary Science Reviews, The Holocene, and The Journal of Geology). The topics of the articles were classified into six themes (paleohydrology, earth surface processes and materials, paleooceanology, paleobiology, palaeoclimatology, and chronology) and 19 subthemes (hydrology, flood, fluvial, glacier, fluvial/glacier, sedimentology, soil, slope process, periglacial, peat land, eolian, sea-level, biology, vegetation, zoology, vegetation/zoology, archaeology, climate, atmosphere, and chronology). The collected data consist of the journal name, information about each paper (authors, title, volume, year, and page numbers), site location (country name, longitude, and latitude), theme, subtheme, keywords, DOI (Digital Object Identifier), and period (era). Location data are indispensable for paleoenvironmental studies. The PaleoGeo shows information with a map, which is an advantage of this database system. However, the number of the paleoenvironmental studies is growing rapidly and we have to effectively cover them as

  15. Sequence Stratigraphic Appraisal: Coastal Swamp Depobelt In The ...

    African Journals Online (AJOL)

    Mid-Lower Miocene Agbada sedimentary intercalations of “AB” Field in the coastal swamp depobelt, Western Niger-Delta, were evaluated to determine their sequence stratigraphic character. The analysis was based on a combination of data sets including logs of six wells to describe lithic variations of the Agbada Formation ...

  16. Measuring Stratigraphic Congruence Across Trees, Higher Taxa, and Time.

    Science.gov (United States)

    O'Connor, Anne; Wills, Matthew A

    2016-09-01

    The congruence between the order of cladistic branching and the first appearance dates of fossil lineages can be quantified using a variety of indices. Good matching is a prerequisite for the accurate time calibration of trees, while the distribution of congruence indices across large samples of cladograms has underpinned claims about temporal and taxonomic patterns of completeness in the fossil record. The most widely used stratigraphic congruence indices are the stratigraphic consistency index (SCI), the modified Manhattan stratigraphic measure (MSM*), and the gap excess ratio (GER) (plus its derivatives; the topological GER and the modified GER). Many factors are believed to variously bias these indices, with several empirical and simulation studies addressing some subset of the putative interactions. This study combines both approaches to quantify the effects (on all five indices) of eight variables reasoned to constrain the distribution of possible values (the number of taxa, tree balance, tree resolution, range of first occurrence (FO) dates, center of gravity of FO dates, the variability of FO dates, percentage of extant taxa, and percentage of taxa with no fossil record). Our empirical data set comprised 647 published animal and plant cladograms spanning the entire Phanerozoic, and for these data we also modeled the effects of mean age of FOs (as a proxy for clade age), the taxonomic rank of the clade, and the higher taxonomic group to which it belonged. The center of gravity of FO dates had not been investigated hitherto, and this was found to correlate most strongly with some measures of stratigraphic congruence in our empirical study (top-heavy clades had better congruence). The modified GER was the index least susceptible to bias. We found significant differences across higher taxa for all indices; arthropods had lower congruence and tetrapods higher congruence. Stratigraphic congruence-however measured-also varied throughout the Phanerozoic, reflecting

  17. Late Quaternary Stratigraphic Architecture of the Santee River Delta, South Carolina, U.S.A.

    Science.gov (United States)

    Long, J. H.; Hanebuth, T. J. J.

    2017-12-01

    The Santee River of South Carolina is the second largest river in terms of drainage area and discharge in the eastern United States and forms the only river-fed delta on the country's Atlantic coast. Significant anthropogenic modifications to this system date back to the early 18th century with the extensive clearing of coastal wetland forest for rice cultivation. In the 1940's the construction of large upstream dams permanently altered the discharge of the Santee River. These modifications are likely documented within the sedimentary record of the Santee Delta as episodes of major environmental changes. The Piedmont-sourced Santee River system incised its valley to an estimated depth of 20 m during lower glacial sea level. Sedimentation during the subsequent Holocene transgression and highstand has filled much of this accommodation. The Santee system remains largely under-investigated with only a handful of studies completed in the 1970's and 1980's based on sediment cores and cuttings. Through the use of high frequency seismic profiles (0.5 - 24 kHz), sediment cores, and other field data, we differentiate depositional units, architectural elements, and bounding surfaces with temporal and spatial distributions reflecting the changing morphodynamics of this complex system at multiple scales. These lithosomes are preserved within both modern inshore and offshore settings and were deposited within a range of paralic environments by processes active on fluvial/estuarine bars, floodplains, marshes, tidal flats, spits, beach ridges, and in backbarrier settings. They are bound by surfaces ranging from diastems to regional, polygenetic, low-angle and channel-form erosional surfaces. Detailed descriptions of cores taken from within the upper 6 m of the modern lower delta plain document heterolithic, mixed-energy, organic-rich, largely aggradational sedimentation dating back to at least 5 ka cal BP. Offshore, stacked, sand-rich, progradational packages sit atop heterolithic paleochannel-fill successions contained within a framework of regionally extensive, erosional bounding surfaces. Ongoing work focuses on continued data acquisition and integration of inshore and offshore data sets into a coherent model for the Holocene evolution of the Santee Delta.

  18. Stratigraphic and geochemical controls on naturally occurring arsenic in groundwater, eastern Wisconsin, USA

    Science.gov (United States)

    Schreiber, M. E.; Simo, J. A.; Freiberg, P. G.

    High arsenic concentrations (up to 12,000μg/L) have been measured in groundwater from a confined sandstone aquifer in eastern Wisconsin. The main arsenic source is a sulfide-bearing secondary cement horizon (SCH) that has variable thickness, morphology, and arsenic concentrations. Arsenic occurs in pyrite and marcasite as well as in iron oxyhydroxides but not as a separate arsenopyrite phase. Nearly identical sulfur isotopic signatures in pyrite and dissolved sulfate and the correlation between dissolved sulfate, iron, and arsenic concentrations suggest that sulfide oxidation is the dominant process controlling arsenic release to groundwater. However, arsenic-bearing oxyhydroxides can potentially provide another arsenic source if reducing conditions develop or if they are transported as colloids in the aquifer. Analysis of well data indicates that the intersection of the SCH with static water levels measured in residential wells is strongly correlated with high concentrations of arsenic in groundwater. Field and laboratory data suggest that the most severe arsenic contamination is caused by localized borehole interactions of air, water, and sulfides. Although arsenic contamination is caused by oxidation of naturally occurring sulfides, it is influenced by water-level fluctuations caused by municipal well pumping or climate changes, which can shift geographic areas in which contamination occurs. Résumé De fortes concentrations en arsenic, jusqu'à 12000μg/L, ont été mesurées dans l'eau souterraine d'un aquifère gréseux captif, dans l'est du Wisconsin. La principale source d'arsenic est un horizon à cimentation secondaire (SCH) comportant des sulfures, dont l'épaisseur, la morphologie et les concentrations en arsenic sont variables. L'arsenic est présent dans la pyrite et dans la marcassite, de même que dans des oxy-hydroxydes de fer, mais non pas dans une phase séparée d'arsénopyrite. Les signatures isotopiques du soufre presque identiques dans la pyrite et dans les sulfates dissous et la corrélation entre les concentrations en sulfates, en fer et en arsenic dissous laissent penser que l'oxydation des sulfures est le processus dominant contrôlant la libération de l'arsenic dans les eaux souterraines. Cependant, les oxy-hydroxydes contenant de l'arsenic sont susceptibles d'être une autre source d'arsenic si des conditions réductrices apparaissent ou s'ils sont transportés dans l'aquifère sous forme de colloïdes. L'analyse des données provenant de puits montre que l'intersection entre le SCH et les niveaux statiques des puits domestiques est fortement corrélée à de fortes concentrations en arsenic dans les eaux souterraines. Des données de terrain et de laboratoire conduisent à penser que la contamination en arsenic la plus forte est causée par l'interaction localisée aux forages entre l'air, l'eau et les sulfures. Bien que la contamination en arsenic soit causée par l'oxydation de sulfures présents naturellement, elle est influencée par les fluctuations du niveau piézométrique causées par les pompages du captage municipal ou par les variations climatiques, ce qui peut conduire au déplacement des zones géographiques où se produisent les contaminations. Resumen Se han medido concentraciones de arsénico muy altas (de hasta 12000μg/L) en las aguas subterráneas de un acuífero confinado, en areniscas, localizado en la parte oriental de Wisconsin (EEUU). La fuente principal de arsénico es un horizonte de cementación secundaria (SCH) con un alto contenido en sulfuros, y con una gran variabilidad en espesor, morfología y concentraciones de As. El arsénico aparece en piritas y marcasitas, además de en oxihidróxidos de hierro, pero no como una fase independiente de arsenopiritas. El hecho que la marca isotópica de piritas y sulfatos disueltos sea muy similar, y que exista una gran correlación entre las concentraciones de sulfato disuelto, hierro y arsénico sugiere que la oxidación de sulfuros es el proceso que controla la aportación de arsénico al agua subterránea. Sin embargo, los oxihidróxidos con alto contenido en arsénico podrían suponer otra fuente de arsénico si se llegaran a desarrollar condiciones reductoras o si se transportaran como coloides por el acuífero. De los datos procedentes de pozos, se ve una fuerte correlación entre la presencia de altas concentraciones de As en el agua y que el nivel freático intersecte el SCH. Los datos de campo y de laboratorio indican que los puntos con mayor contaminación de arsénico son debidos a interacciones de carácter local y en los propios pozos entre aire, agua y sulfuros. Aunque la contaminación por As está causada por la oxidación de sulfuros presentes de manera natural, también está muy influenciada por las fluctuaciones en los niveles freáticos causadas por bombeos o cambios climáticos.

  19. Possible extrinsic controls on the Ordovician radiation: Stratigraphic evidence from the Great Basin, western USA

    Energy Technology Data Exchange (ETDEWEB)

    Droser, M.L. (Univ. of California, Riverside, CA (United States). Dept. of Earth Sciences); Fortey, R.A. (Natural History Museum, London (United Kingdom). Dept. of Palaeontology)

    1993-04-01

    The Ordovician radiation has been previously examined by looking at 1/analyses of patterns of diversification within small clades, 2/analyses of large databases to elucidate large-scale paleoecological patterns such as increased tiering and onshore-offshore shifts associated with this radiation. In order to resolve the relationships between these two scales of analysis there is critical need to examine in detail the paleoecology and possible biofacies shifts associated with the Ordovician radiation. The authors have examined the base of the Whiterock Series (Lower-Middle Ordovician) in the Great Basin as it represents one of the most complete records of the Ordovician radiation on the North American continent. Detailed field evidence suggests that the base of the Whiterock does not represent a simple faunal turnover but corresponds with the first occurrences in the region of groups that come to dominate the rest of the Paleozoic. Among the trilobites, this includes the lichides, calymenids, proetides, and phacopides. Similar patterns are found among the dominate Paleozoic bivalve, cephalopod, brachiopod and graptolite clades. Global correlation of this time interval suggests that this pattern of first broad geographic occurrences is not unique to North America. This boundary corresponds with a globally recognized sea level lowstand. In the Great Basin, significant facies shifts are present in shallow and deep water settings. While extrinsic controls are commonly reserved for extinctions, these data suggest that extrinsic factors may have been significant in the timing of the Paleozoic fauna rose to dominance.

  20. Use-inspired Paleoenvironmental Science and Data: A Deep Whole-Earth Time Dimension

    Science.gov (United States)

    Overpeck, J. T.

    2016-12-01

    The field of paleoenvironmental science has matured dramatically over the last 30 years, and paleo-data are now widely used to inform policy and other decision-making. The IPCC now incorporates paleo-perspectives in a prominent manner - centuries to millennia-long paleo records are key to assessing the full range of possible climate system behavior, how the Earth's climate system responds to large changes in forcing, how climate change may impact ecological, hydrological, oceanographic and many other systems that humans are concerned about. Paleohydroclimatic data increasingly are used by water managers, just as forest managers use paleo-fire data to understand the natural rhythms and processes so critical to healthy ecosystems and the services they provide. Paleo-data are now widely used for model evaluation, and for understanding what models may be missing - in this sense, the millennia-long observational record provided by paleoenvironmental data helps us avoid costly surprises. Success comes with responsibility, however. The more paleo-data and paleo-based understanding informs policy and other decisions, the more critical it is that paleo-data and the results built on them need to be openly shared, easily accessible and reproducible. The value of paleo-data grows with use, and thus data sharing serves to grow value to the society that ultimately pays for the research. The tradition of sharing paleo-data is built on an even longer tradition of sharing samples, and yet innovations are still needed to make sure samples are managed for future use, particularly as natural archives like glaciers, caves and corals are lost to climate change and other human activity. Scientific journals and data centers are constantly innovating; paleoenvironmental scientists must all play their part as well.

  1. Determination of Heat Capacity of Yucca Mountain Stratigraphic Layers

    International Nuclear Information System (INIS)

    T. Hadgu; C. Lum; J.E. Bean

    2006-01-01

    The heat generated from the radioactive waste to be placed in the proposed geologic repository at Yucca Mountain, Nevada, will affect the thermal-hydrology of the Yucca Mountain stratigraphic layers. In order to assess the effect of the movement of repository heat into the fractured rocks accurate determination of thermodynamic and hydraulic properties is important. Heat capacity is one of the properties that are required to evaluate energy storage in the fractured rock. Rock-grain heat capacity, the subject of this study, is the heat capacity of the solid part of the rock. Yucca Mountain consists of alternating lithostratigraphic units of welded and non-welded ash-flow tuff, mainly rhyolitic in composition and displaying varying degrees of vitrification and alteration. A number of methods exist that can be used to evaluate heat capacity of the stratigraphic layers that consist of different compositions. In this study, the mineral summation method has been used to quantify the heat capacity of the stratigraphic layers based on Kopp's rule. The mineral summation method is an addition of the weighted heat capacity of each mineral found in a specific layer. For this study the weighting was done based on the mass percentage of each mineral in the layer. The method utilized a mineralogic map of the rocks at the Yucca Mountain repository site. The Calico Hills formation and adjacent bedded tuff layers display a bimodal mineral distribution of vitric and zeolitic zones with differing mineralogies. Based on this bimodal distribution in zeolite abundance, the boundary between the vitric and zeolitic zones was selected to be 15% zeolitic abundance. Thus, based on the zeolite abundance, subdivisions have been introduced to these layers into ''vitric'' and ''zeolitic'' zones. Heat capacity values have been calculated for these layers both as ''layer average'' and ''zone average''. The heat capacity determination method presented in this report did not account for spatial

  2. Fossil preservation and the stratigraphic ranges of taxa

    Science.gov (United States)

    Foote, M.; Raup, D. M.

    1996-01-01

    The incompleteness of the fossil record hinders the inference of evolutionary rates and patterns. Here, we derive relationships among true taxonomic durations, preservation probability, and observed taxonomic ranges. We use these relationships to estimate original distributions of taxonomic durations, preservation probability, and completeness (proportion of taxa preserved), given only the observed ranges. No data on occurrences within the ranges of taxa are required. When preservation is random and the original distribution of durations is exponential, the inference of durations, preservability, and completeness is exact. However, reasonable approximations are possible given non-exponential duration distributions and temporal and taxonomic variation in preservability. Thus, the approaches we describe have great potential in studies of taphonomy, evolutionary rates and patterns, and genealogy. Analyses of Upper Cambrian-Lower Ordovician trilobite species, Paleozoic crinoid genera, Jurassic bivalve species, and Cenozoic mammal species yield the following results: (1) The preservation probability inferred from stratigraphic ranges alone agrees with that inferred from the analysis of stratigraphic gaps when data on the latter are available. (2) Whereas median durations based on simple tabulations of observed ranges are biased by stratigraphic resolution, our estimates of median duration, extinction rate, and completeness are not biased.(3) The shorter geologic ranges of mammalian species relative to those of bivalves cannot be attributed to a difference in preservation potential. However, we cannot rule out the contribution of taxonomic practice to this difference. (4) In the groups studied, completeness (proportion of species [trilobites, bivalves, mammals] or genera [crinoids] preserved) ranges from 60% to 90%. The higher estimates of completeness at smaller geographic scales support previous suggestions that the incompleteness of the fossil record reflects loss of

  3. Application of organic facies in sedimentological-stratigraphical model of the Oligo-Miocene and Miocene of the Campos Basin; Aplicacao da faciologia organica no modelo sedimentologico-estratigrafico do Oligo-Mioceno e Mioceno da Bacia de Campos

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca Filho, Joao Graciano; Mendonca, Joalice de Oliveira; Oliveira, Antonio Donizeti de; Torres, Jaqueline [Universidade Federal do Rio de Janeiro (UFRJ). Centro de Ciencias Exatas e da Natureza. Inst. de Geociencias (Brazil)], e-mails: graciano@geologia.ufrj.br, donizeti@lafo.geologia.ufrj.br, joalice@lafo.geologia.ufrj.br, jaqueline@lafo.geologia.ufrj.br; Menezes, Taissa Rego [Centro de Pesquisas da Petrobras (CENPES), RJ (Brazil). P e D em Geociencias. Gerencia de Geoquimica], e-mail: taissamenezes@petrobras.com.br; Santos, Viviane Sampaio Santiago dos; Arienti, Luci Maria [Centro de Pesquisas da Petrobras (CENPES), RJ (Brazil). P e D em Geociencias. Gerencia de Sedimentologia e Estratigrafia], e-mails: vsss@petrobras.com.br, arienti@petrobras.com.br

    2010-05-15

    This study integrates palynofacies analyses and the sedimentological and stratigraphic model of the Oligo-Miocene/Miocene siliciclastic deposits from the stratigraphic interval of the shallow continental platform up to the slope/basin of the Oligo-Miocene/ Miocene of the Campos Basin proposed. The main objective of the palynofacies study was to characterize the particulate sedimentary organic matter to obtain information about the proximal-distal relationship and the sedimentary organic matter preservation and depositional environmental conditions. The 158 core samples collected in 29 wells of the 9 oil production fields (Albacora, Barracuda, Marlim Sul, Marlim, Voador, Marlim Leste, Moreia and Albacora Leste), were studied. This technique provides information about the proximal-distal relationship and the paleoenvironmental conditions of deposition and preservation of sedimentary organic matter, to facilitate the evaluation and comparisons between the associations of particulate organic components. Thus, the palynofacies technique can be used as another tool in the characterization of depositional systems, based on the spatial and temporal distribution of sedimentary intervals. In general the palynofacies assemblages showed the predominance of the Phytoclast Group (terrestrial derived organic matter) at various degradation stages due to the selective preservation process diagnosed in the studied samples. Some samples, revealed high dinocysts percentages indicative of transgressive depositional conditions. From the obtained data, it was possible to characterize the stratigraphic sequences according to the distribution of particulate organic content (e.g. influence of fluvio-deltaic systems, oxygen system, regressive-transgressive tendencies of each sequence). Additional analyses of Total Organic Carbon (% wt) showed the control of the particulate components from the Phytoclast Group on the TOC (% wt) content, suggesting that the relative sea-level variation curves

  4. Pollen-based paleoenvironmental and paleoclimatic change at Lake Ohrid (south-eastern Europe) during the past 500 ka

    NARCIS (Netherlands)

    Sadori, Laura; Koutsodendris, Andreas; Panagiotopoulos, Konstantinos; Masi, Alessia; Bertini, Adele; Combourieu-Nebout, Nathalie; Francke, Alexander; Kouli, Katerina; Joannin, Sébastien; Mercuri, Anna Maria; Peyron, Odile; Torri, Paola; Wagner, Bernd; Zanchetta, Giovanni; Sinopoli, Gaia; Donders, Timme H.

    2016-01-01

    Lake Ohrid is located at the border between FYROM (Former Yugoslavian Republic of Macedonia) and Albania and formed during the latest phases of Alpine orogenesis. It is the deepest, the largest and the oldest tectonic lake in Europe. To better understand the paleoclimatic and paleoenvironmental

  5. Accommodation and supply—a dual control on stratigraphic sequences

    Science.gov (United States)

    Schlager, Wolfgang

    1993-07-01

    It is widely accepted that both eustatic and tectonically controlled regional changes of sea level have contributed to the record of stratigraphic sequences. I suggest that environmental change be added as a third, autonomous control. Sedimentologic principles clearly indicate that sequences and their systems tracts are controlled by the interplay of two rates —the rate of change in accommodation (space available for sedimentation) and the rate of sediment supply. Sea level has direct control on accommodation, but its influence on sediment supply is remote and easily overshadowed by environmental factors. For instance, the record of the most recent sea-level rise is a transgressive systems tract where supply is low; it is a prograding highstand systems tract in deltas where the supply is high. Examples of sequence boundaries generated by changes in sediment supply include tectonically driven shifts in sediment input into basins, changes in ocean currents, pulsating supply from failure of submarine slopes and drowning of carbonate platforms by environmental stress. Furthermore, the stratigraphic sequences in fluviatile continental basins are physically removed from sea-level induced changes in accommodation and must have formed by changes in the rate and pattern of supply. Subaerial exposure of marine sediments at the sequence boundary is a most important criterion for recognizing sea level cycles as opposed to supply cycles. Other criteria include downstepping of shelf breaks and characteristic patterns in the spacing of time lines within sequences. Some third-order cycles (ca. 0.5-3 Ma duration) meet these criteria, others do not. Cycle-stacking patterns and the shifting facies belts on cratons indicate that many second- and third-order cycles lack pronounced exposure unconformities and represent gradual changes superimposed on more rapid, shorter oscillations. Seismic data yield poor images of these gradational changes because they lack resolution. Seismic

  6. Venusian extended ejecta deposits as time-stratigraphic markers

    Science.gov (United States)

    Izenberg, Noam R.

    1992-01-01

    Use of impact crater ejects at time-stratigraphic markers was established during lunar geologic mapping efforts. The basic premise is that the deposition of impact ejecta, either by itself or mixed with impact-excavated material, is superimposed on a surface. The deposit becomes an observable, mappable unit produced in a single instant in geologic time. Up to two-thirds of Venus craters exhibit extended ejecta deposits. A reconnaissance survey of 336 craters (about 40 percent of the total population) was conducted. About half the craters examined were located in and around the Beta-Atla-Themis region, and half were spread over the western hemisphere of the planet. The survey was conducted using primarily C1-MIDR images. The preliminary survey shows: (1) of the 336 craters, 223 were found to have extended ejecta deposits. This proportion is higher than that found in other Venus crater databases by up to a factor of 2. (2) 53 percent of all extended ejecta craters were unambiguously superimposed on all volcanic and tectonic units. Crater Annia Faustina's associated parabolic ejecta deposit is clearly superimposed on volcanic flows coming from Gula Mons to the west. Parabola material from Faustina has covered the lava flows, smoothing the surface and reducing its specific backscatter cross section. The stratigraphy implies that the parabola material is the youngest observable unit in the region. (3) 12 percent of extended ejecta deposits are superimposed by volcanic materials. Crater Hwangcini has extended ejecta that has been covered by volcanic flows from a dome field to the northwest, implying that the volcanic units were emplaced subsequent to the ejecta deposit and are the youngest units in the locality. (4) It is difficult to determine the stratigraphic relationships of the remaining extended ejecta deposits in SAR at C1-MIDR resolution. Examination of higher resolution images and application of the other Magellan datasets in systematic manner should resolve

  7. OWL representation of the geologic timescale implementing stratigraphic best practice

    Science.gov (United States)

    Cox, S. J.

    2011-12-01

    The geologic timescale is a cornerstone of the earth sciences. Versions are available from many sources, with the following being of particular interest: (i) The official International Stratigraphic Chart (ISC) is maintained by the International Commission for Stratigraphy (ICS), following principles developed over the last 40 years. ICS provides the data underlying the chart as part of a specialized software package, and the chart itself as a PDF using the standard colours; (ii) ITC Enschede has developed a representation of the timescale as a thesaurus in SKOS, used in a Web Map Service delivery system; (iii) JPL's SWEET ontology includes a geologic timescale. This takes full advantage of the capabilities of OWL. However, each of these has limitations - The ISC falls down because of incompatibility with web technologies; - While SKOS supports multilingual labelling, SKOS does not adequately support timescale semantics, in particular since it does not include ordering relationships; - The SWEET version (as of version 2) is not fully aligned to the model used by ICS, in particular not recognizing the role of the Global Boundary Stratotype Sections and Point (GSSP). Furthermore, it is distributed as static documents, rather than through a dynamic API using SPARQL. The representation presented in this paper overcomes all of these limitations as follows: - the timescale model is formulated as an OWL ontology - the ontology is directly derived from the UML representation of the ICS best practice proposed by Cox & Richard [2005], and subsequently included as the Geologic Timescale package in GeoSciML (http://www.geosciml.org); this includes links to GSSPs as per the ICS process - key properties in the ontology are also asserted to be subProperties of SKOS properties (topConcept and broader/narrower relations) in order to support SKOS-based queries; SKOS labelling is used to support multi-lingual naming and synonyms - the International Stratigraphic Chart is implemented

  8. Paleoenvironmental and Paleoecological Reconstruction of the Ancient Maya Port Site of Vista Alegre, Quintana Roo, Mexico

    Science.gov (United States)

    Rissolo, D.; Jaijel, R.; Glover, J. B.; Goodman, B.; Beddows, P. A.; Carter, A.; Smith, D.

    2013-12-01

    Ancient Maya ports along the largely unstudied northeast coast of the Yucatan Peninsula once supported a network of trade routes linking people, goods, and ideas from across Mesoamerica. The Costa Escondida Project has focused on the interrelationships between the ancient Maya and their dynamic coastal environment along the shores of the Laguna Holbox. Central to our interdisciplinary efforts is a paleoenvironmental and paleoecological reconstruction of the key port of Vista Alegre - a low-lying island surrounded by a complex mosaic of costal ecosystems, sedimentological facies, and hydrological conditions. Geoarchaeological field methods, such as sediment coring, have made possible multiproxy analyses that enable us to better understand sea level fluctuations and the morphology of the shoreline and harboring locations over time, as well as changes in ecosystem biodiversity, which would have presented the maritime Maya with unique challenges and opportunities.

  9. Impact of prehistoric cooking practices on paleoenvironmental proxies in shell midden constituents

    Science.gov (United States)

    Müller, Peter; Staudigel, Philip; Murray, Sean T.; Westphal, Hildegard; Swart, Peter K.

    2016-04-01

    Paleoenvironmental proxy records such as oxygen isotopes of calcareous skeletal structures like fish otoliths or mollusk shells provide highest-resolution information about environmental conditions experienced by the organism. Accumulations of such skeletal structures by ancient coastal populations in so called "shell midden" deposits provide us with sub-seasonally resolved paleoclimate records covering time spans up to several millennia. Given their high temporal resolution, these deposits are increasingly used for paleoclimate reconstructions and complement our understanding of ancient climate changes. However, gathered as comestibles, most of these skeletal remains were subject to prehistoric cooking methods prior to deposition. The associated alteration of the chemical proxy signatures as well as the subsequent error for paleoenvironmental reconstructions remained almost entirely neglected so far. Here, we present clumped isotope, conventional oxygen and carbon isotopes as well as element:Ca ratios measured in modern bivalve shells after exposing them to different prehistoric cooking methods. Our data show that most cooking methods considerably alter commonly used paleoclimate proxy systems which can lead to substantial misinterpretations of ancient climate conditions. Since the magnitude of chemical alteration is not distinguishable from natural temperature variability in most coastal settings, the alteration of shell midden constituents by prehistoric cooking remains likely unnoticed in most cases. Thus, depending on the cooking method, pre-depositional heating might have introduced considerable errors into previous paleoclimate studies. However, our data also show that clumped isotope thermometry represents a suitable diagnostic tool to detect such pre-depositional cooking events and also allows differentiating between the most commonly applied prehistoric cooking methods.

  10. Middle Miocene paleoenvironmental crises in Central Eurasia caused by changes in marine gateway configuration

    Science.gov (United States)

    Palcu, D. V.; Golovina, L. A.; Vernyhorova, Y. V.; Popov, S. V.; Krijgsman, W.

    2017-11-01

    Marine gateways prove to be important factors for changes in the ecology and biochemistry of marginal seas. Changes in gateway configuration played a dominant role in the Middle Miocene paleogeographic evolution of the Paratethys Sea that covered Central Eurasia. Here, we focus on the connection between the Central (CP) and Eastern Paratethys (EP) to understand the paleoenvironmental changes caused by the evolution of this marine gateway. We first construct an integrated magneto-biostratigraphic framework for the late Langhian-Serravallian (Chokrakian-Karaganian-Konkian-Volhynian) sedimentary record of the eastern domain, which allows a correlation to the well-dated successions west of the gateway. The magneto-biostratigraphic results from the Zelensky-Panagia section on the Black Sea coast of Russia show that the Chokrakian/Karaganian boundary has an age of 13.8 Ma, the Karaganian/Konkian boundary is dated at 13.4 Ma, and the Konkian/Volhynian boundary at 12.65 Ma. We identify three major phases on gateway functioning that are reflected in specific environmental changes. During the Karaganian, the EP turned into a lake-sea that supplied a unidirectional flow of low-salinity waters to the west, where the CP sea experienced its Badenian Salinity Crisis. This configuration is remarkably similar to the Mediterranean during its Messinian Salinity Crisis. The second phase is marked by a marine transgression from the west, reinstalling open-marine conditions in the CP and causing marine incursions in the EP during the Konkian. The Volhynian is characterized by a new gateway configuration that allows exchange between CP and EP, creating unified conditions all over the Paratethys. We hypothesize that a density driven pumping mechanism is triggered by the increase in connectivity at the Konkian/Volhynian boundary, which simultaneously caused major paleoenvironmental changes at both sides of the gateway and led to the Badenian-Sarmatian extinction event in the CP.

  11. Drilling rate for the Cerro Prieto stratigraphic sequence

    Energy Technology Data Exchange (ETDEWEB)

    Prian C, R.

    1981-01-01

    Drilling practice at the field has been modified in several ways as better information is being obtained. The stratigraphic sequence of the area is made up of three sedimentary rock units of deltaic origin having different densities. These units have been named non-consolidated, semi-consolidated, and consolidated rocks; the thermal reservoirs are located in the latter. To investigate how the drilling rates are affected by the three rock units, plots of drilling advance versus time were made for a large number of wells. A typical plot is shown and drilling rates are practically constant in three different zones; that is, the drilling rate has only two breaks or changes in slope.

  12. Treinta y Tres stratigraphic terrain: ex Cuchilla Dionisio terrain. Uruguay

    International Nuclear Information System (INIS)

    Bossi, J.

    2010-01-01

    From 1998 we are discussing if the eastern area of ZCSB is an allochtonous block named TCD or if it belongs to Dom Feliciano belt with an age of 500 - 700 Ma. This crustal block is difficult to study because Laguna Merin Graben cut it in two around 4000 k m2 crustal fragments distant s more de 100 km between them. Southern block which was named T PE by Masquelín (2006) was demonstrated as allochtonous by Bossi and Gaucher (2004) destroying the Cdf model but seriously complicating the stratigraphic terminology. It is proposed to do some changes in order to profit the general agreement about allochtomy. The CDT with change by Treinta y Tres terrane; T PE become sub - terrain Punta del Este; sub - terrain Cuchilla Dionisio for the septetrional block. From 1998 we are discussing if the eastern area of ZCSB is an allochtonous block named TCD or if it belongs to Dom Feliciano belt with an age of 500 - 700 Ma. This crustal block is difficult to study because Laguna Merín Graben cut it in two around 4000 k m2 crustal fragments distant s more de 100 km between them. Southern block which was named T PE by Masquelín (2006) was demonstrated as allochtonous by Bossi and Gaucher (2004) destroying the CDF model but seriously complicating the stratigraphic terminology. It is proposed to do some changes in order to profit the general agreement about allochtomy. The CDT with change by Treinta y Tres terrain; TPE become sub - terrain Punta del Este; sub - terrain Cuchilla Dionisio for the septetrional block

  13. Chemical Contaminants as Stratigraphic Markers for the Anthropocene

    Science.gov (United States)

    Kruge, M. A.

    2012-12-01

    Thousands and even millions of years from now, widespread anthropogenic contaminants in sediments would likely persist, incorporated into the geological record. They would inadvertently preserve evidence of our present era (informally designated as the Anthropocene Epoch) characterized by large human populations engaged in intensive industrial and agricultural activities. Hypothetical geologists in the distant future would likely find unusually high concentrations of a wide variety of contaminants at stratigraphic levels corresponding to our present time, analogous to the iridium anomaly marking the bolide impact event at the close of the Cretaceous Period. These would include both organic and inorganic substances, such as industrially-derived heavy metals (e.g., Hg, Pb, Cr, Zn) and hydrocarbons, both petrogenic (derived directly from petroleum) and pyrogenic (combustion products). While there are natural sources for these materials, such as volcanic eruptions, wildfires, and oil seeps, their co-occurrence would provide a signature characteristic of human activity. Diagnostic assemblages of organic compounds would carry an anthropogenic imprint. The distribution of polycyclic aromatic hydrocarbons (PAHs) in a sediment sample could distinguish between natural and human sources. Stable isotopic signatures would provide additional evidence. Concentrations of contaminants in the sedimentary record would increase exponentially with increasing proximity to urban source areas, where at present billions of people are collectively consuming vast quantities of fossil fuels and generating large amounts of waste. Aolian and marine transport prior to deposition has been seen at present to globally redistribute detectable amounts of contaminants including Hg and PAHs, even at great distances from principal source areas. For organic contaminants, deposition in an anoxic sedimentary environment could insure their preservation, increasing the likelihood of their inclusion in the

  14. Geochemical and paleoenvironmental record of the early to early late Aptian major episodes of accelerated change: Evidence from Sierra del Rosario, Northeast Mexico

    Science.gov (United States)

    Núñez-Useche, Fernando; Barragán, Ricardo; Moreno-Bedmar, Josep Anton; Canet, Carles

    2015-07-01

    The lower to lower-upper Aptian succession of northern Mexico documents the drowning of the shallow-water Cupido/Cupidito carbonate platform system followed by deposition of the deep-water sediments of the La Peña Formation. Using δ13C stratigraphy, geochemical and mineralogical information coupled with previous microfacies, paleontological and total organic carbon (TOC) data from a stratigraphic section, which includes such lithological change, this study identifies distinctive episodes of accelerated global environmental change, and determines the paleoenvironmental conditions conducive to the deposition of TOC-rich intervals. Within the Cupidito unit, the Oceanic Anoxic Event 1a (OAE 1a) is recorded near the base of the section and the Intra-Furcata Negative Excursion in the topmost beds of the unit. The upper part of the section, within the La Peña Formation, is correlatable with the Noire level. Organic-carbon rich intervals occur in the lower and middle part of the OAE 1a, upper part of the Cupidito unit, base of the La Peña Formation, and in the Noire level equivalent. Reducing conditions within the sediment and oxic-dysoxic at the seafloor, locally controlled, persisted both before and during OAE 1a interval in the Cupidito lagoon. Oxygen-depleted conditions (dysoxic-anoxic) were more permanent and stronger during the deposition of the base of the la Peña Formation and the Noire equivalent level. It is proposed here that deposition of the lower-middle part of the OAE 1a and the base of the La Peña Formation was influenced by climate-controlled increases in detrital and accompanying nutrient influx that supplied especially biolimiting nutrients (Fe, P), fostering marine productivity and TOC burial. Upwelling of nutrient-rich deeper waters and minor arrival of nutrients from runoff, both account for the domination of radiolaria and organic-carbon burial during the Noire level equivalent. Record of the OAE 1a time-equivalent facies in the Cupidito

  15. Time as An Important Soil-Forming Factor Influencing Modern and Ancient Magnetic Susceptibility Enhancement Along the Delaware River Valley, USA

    Science.gov (United States)

    Stinchcomb, G. E.; Peppe, D. J.; Driese, S. G.

    2011-12-01

    Magnetic susceptibility is an increasingly popular low-cost method for rapidly assessing paleoclimate and paleoenvironmental impact on buried soils. The goal of this study is to determine the primary influence(s) on soil magnetic susceptibility along floodplain, terrace and upland soils in the middle Delaware River Valley, USA, using environmental magnetic, pedologic, and stratigraphic techniques. Two-hundred thirty samples were collected from age-constrained sandy, quartz-rich, floodplain, terrace, and upland soils (Entisols, Inceptisols). A Kruskal-Wallis (K-W) and post-hoc Tukey-Kramer (T-K) (α=0.05) multiple comparisons analysis on 176 mass-specific low-field susceptibility (Xlf) assays show that A and B horizons are magnetically enhanced compared to C and E horizons (ptesting show that Xlf results, when grouped by floodplain-terrace designation (i.e., chronofunction) are significantly different (p<0.0001). The older T3 terrace and upland Xlf values (0.34±0.14 10^-6 m^3 kg^-1) are greater than the younger T2 terrace (0.18±0.06 10^-6 m^3 kg^-1) values, which are greater than modern floodplain (0.09±0.01 10^-6 m^3 kg^-1) Xlf values. These data suggest that longer intervals of soil formation enhance the Χlf value. This hypothesis is further supported when 159 Xlf values are plotted vs. age for the entire Holocene. A locally-weighted regression smoothing curve (LOESS) shows two distinct intervals of magnetic enhancement during previously established dry intervals, the early and late-middle Holocene. We hypothesize that prolonged drought during the early and middle Holocene reduced flood frequency and magnitude and the likelihood of soil burial, resulting in longer soil forming intervals and higher Xlf values. Although precipitation influences the Xlf signature, the results from this study suggest that the magnetic susceptibility values of well-drained buried floodplain soils along the Delaware River Valley are partly a function of time.

  16. Revised stratigraphic nomenclature and correlation of early proterozoic rocks of the Darwin - Katherine region, Northern Territory

    International Nuclear Information System (INIS)

    Needham, R.S.; Stuart-Smith, P.G.

    1984-01-01

    New stratigraphic names and correlations are given for parts of the Early Proterozoic Pine Creek Geosyncline metasedimentary sequence and overlying felsic volcanics of the Darwin-Katherine region. They have significant implications for the stratigraphic distribution of uranium mineralisation in the Rum Jungle, Alligator Rivers and South Alligator Valley uranium fields

  17. Regionally heterogeneous paleoenvironmental responses in the West African and South American monsoon systems on glacial to millennial timescales

    Science.gov (United States)

    Shanahan, T. M.; Hughen, K. A.; van Mooy, B.; Overpeck, J. T.; Baker, P. A.; Fritz, S.; Peck, J. A.; Scholz, C. A.; King, J. W.

    2008-12-01

    Although millennial-scale paleoenvironmental changes have been well characterized for high latitude sites, short-term climate variability in the tropics is less well understood. While the Intertropical Convergence Zone may act as an integrator of tropical climate changes, regional factors also play an important role in controlling the tropical response to climate forcing. Understanding these influences, and how they modulate the response to global climate forcing under different mean climate states is thus important for assessing how the tropics may respond to future climate change. Here, we examine new centennial-resolution records of paleoenvironmental change from isotopic and relative abundance data from molecular biomarkers in sediment cores from Lake Bosumtwi and Lake Titicaca. We assess the relative response of the West African and South American monsoon systems to millennial and suborbital-scale climate variability over the last ca. 30,000 years. While there is evidence for synchronous climate variability in the two systems, the dominant paleoenvironmental changes appear largely decoupled, highlighting the importance of regional climatology in controlling the response to climate forcing in tropical regions.

  18. Stratigraphic and microfossil evidence for hydroclimate changes over the middle to late Holocene in the northern Bahamas from an inland saline lake

    Science.gov (United States)

    van Hengstum, P. J.; Maale, G. E.; Donnelly, J. P.; Onac, B. P.; Sullivan, R.; Winkler, T. S.; Albury, N. A.

    2016-12-01

    No Man's Land is one of the largest inland lakes on the Little Bahama Bank in the northern Bahamas, so its paleoenvironmental history may provide insight into how the regional hydroclimate developed over the Holocene. In its modern state, the site is shallow (aquatic invertebrates (e.g., ostracodes, foraminifera, aquatic mollusks) indicate that the site was a terrestrial ecosystem. However, the site transitioned into a subaqueous freshwater environment at 6400 Cal yrs BP, and the site became a palustrine-lacustrine setting thereafter until 4200 Cal yrs BP. During this time, widespread palustrine-lacustrine carbonate deposition and the appearance of freshwater to low mesohaline microfossils indicates that the lake's salinity was likely oligohaline (charophytes, ostracodes: Candona annae, Cypridopsis vidua, foraminifera: Helenina davescottensis, mollusks: Planorbis, Hydrobia). A salinity increase at 4200 Cal yrs BP is inferred from the appearance of the ostracode Cyprideis americana that typically prefers salinities exceeding 10 psu, and deposition of laminated microbial mats. Thereafter, an organic- rich, algal sapropel unit accumulated that was devoid of any microfossils or mollusks. This unit suggests that the lake hosted a stratified water column, where surface waters supported phytoplankton primary productivity and corrosive or anoxic bottom water conditions either hampered microfossil growth or precluded their preservation. The transition to the modern environment ( 20 psu) at 2600 cal yrs BP is characterized by diversification of brackish ostracodes (Aurila floridana, Dolerocypria inopinata, and Hemicyprideis setipunctata), foraminifera (Elphidium spp., Ammonia beccarii, Triloculina oblonga) and mollusks (Anomalocardia, Cerithidea). Over the middle to late Holocene, it appears that the stratigraphic development and salinity changes in No Man's Land has been driven by groundwater-level rise in response to Holocene sea-level rise, the regional delivery of fresh

  19. Stratigraphical distribution of the Ordovician conodont Erraticodon Dzik in Argentina

    Science.gov (United States)

    Heredia, S.; Carlorosi, J.; Mestre, A.; Soria, T.

    2013-08-01

    Three different species of the Ordovician genus Erraticodon Dzik are described and illustrated. Erraticodon patu Cooper is reported from the Lower-Midde Ordovician strata of the Acoite and Alto del Cóndor formations. E. cf. Erraticodon balticus and Erraticodon hexianensis from Middle Ordovician carbonate deposits of the San Juan Formation are analyzed and compared to specimens of these species from Australia, China, Newfoundland, and Baltica. E. patu and E. hexianensis are recorded for first time in the San Juan Formation of Precordillera. The elements of E. cf. E. balticus resemble closely E. balticus Dzik but lack the important denticle on the posterior process of the S elements. An evaluation of the stratigraphic occurrences of these species relative to those of key Lower and Middle Ordovician conodont species such as Trapezognathus diprion Lindström, Oepikodus intermedius Serpagli, Baltoniodus triangularis (Lindström), Baltoniodus navis Lindström, Yangtzeplacognathus crassus (Chen and Zhang) and Eoplacognathus pseudoplanus (Viira) indicates they value for biostratigraphic correlation.

  20. Past and Present Weathering Recorded in Cretaceous Shale Samples from Colombia - Implications for Paleoenvironmental Reconstructions

    Science.gov (United States)

    Mahoney, C.; März, C.; Wagner, T.

    2016-12-01

    It is well known that for geochemical studies on ancient rocks, outcrop samples can be compromised by present-day weathering. This raises the fundamental question, if only outcrop samples are available, how reliable can paleoenvironmental reconstructions be? To answer this question, shale samples have been gathered from Cretaceous outcrops of the Eastern Cordillera of Colombia, and analysed by XRF and Fe speciation in order to investigate paleo-redox conditions in this margin basin of the Proto-Atlantic. The samples are consistently depleted (relative to average shale) in redox-related trace metals and in total Fe indicating oxic conditions, whereas Fe speciation (highly reactive over total Fe) indicates anoxic conditions. We ask if this depletion in trace metals and total Fe is due to a lack of primary supply from the depositional environment, or if is it caused by modern oxidative outcrop weathering in this tropical mountainous setting? Our results from artificial weathering experiments confirm that certain trace metals U, Zn and Mo are easily leached from the samples, whereas Fe is quantitatively retained in the samples due to conversion of pyrite and siderite to Fe oxides. Pristine samples from wells in the adjacent Middle Magdalena Valley Basin (MMV) also exhibit total Fe depletion, but are up to 2000-fold enriched in Mo. This combined evidence indicates that the depletion of trace metals may be due to contemporary weathering, but there has to be a paleoenvironmental reason behind the low total Fe signature. The Guiana Shield was the probable source of sediment to the Cretaceous basin. The Chemical Index of Alteration suggest the source of detrital material was initially highly weathered (average 83, maximum 95). Ancient laterites have been identified on the Guiana Shield, and retention of Fe in these laterites may explain the low Fe input into the Eastern Cordillera basin. These results confirm that trace metal-based redox proxies may be seriously affected by

  1. A Permian methane seep system as a paleoenvironmental analogue for the pre-metazoan carbonate platforms

    Directory of Open Access Journals (Sweden)

    Lucas Veríssimo Warren

    Full Text Available ABSTRACT: Following the rise of metazoans, the beginning of bioclasticity and substrate competition, the saga of microbial mats was in a fluctuating decline in the end of the Neoproterozoic era. Increases in diversity during the Phanerozoic and punctual upturns in the microbial carbonate production occured after the events of global mass extinctions. Gradually along the Phanerozoic, the microbial colonies occupied isolated niches and grazers-free environments, characterized by physically and/or geochemically stressful conditions, such as those found in saline bays, alkaline lakes and hydrothermal or cold seep vents. Here we report one of the oldest occurrences of a vent camp coupled with cold seepage of methane in the geologic record, associated with well-preserved microbialites and elephant skin structures. During the seep activity, oxygen depletion and high salinity conditions are prohibitive for complex animal life, clearing the way to microbial colonies to flourish. Due to the co-occurrence of high adaptability and low competitiveness of microbial forms, they became highly specialized in stressful conditions. We argue that the sporadic microbial mat upturns in Earth’s history are not restricted to geological periods, following massive death of metazoan species; they also may occur in response to punctual paleoenvironmental conditions that enable microbial colonies to growth. Indeed, the Phanerozoic geological record is punctuated of these examples, in a kind of hide-and-seek game of Precambrian times.

  2. PALEOENVIRONMENTAL RECONSTRUCTION FROM BENTHIC FORAMINIFERAL ASSEMBLAGES OF EARLY HOLOCENE, SHALLOW MARINE DEPOSITS IN GOMBONG, CENTRAL JAVA

    Directory of Open Access Journals (Sweden)

    Luli Gustiani

    2017-07-01

    Full Text Available A 30m-long sediment core covering the Holocene period was taken from the area of Gombong in the southern part of Central Java. The sediments were deposited in a shallow marine to lagoonal environment that was confirmed by the dominance of Ammonia beccarii along the core intervals. In addition, the species Quinqueloculina poeyana, Miliolinella lakemacquariensis, and Miliolinella subrotunda were also found in the sediments that are typical of normal shallow marine conditions. The decrease and increase in the abundance of these species throughout the core is an expression of sea level change in the area, which results the environmental changes. Low sea level is expressed by the dominance of Ammonia beccarii, and the low abundances or absence of the other three species. In contrast, high sea level stands are reflected by the presence of all four species. The high sea level would imply favorable conditions for benthic foraminifera because it would result in normal shallow marine conditions in the area. Finally, from this benthic assemblages study, it can be assumed that the environmental transformation from the originally shallow marine environment into land was occurred at level 5.5m depths of the sediment core, when all benthic foraminifera were terminated, including Ammonia beccarii. These new results from the shallow marine deposits in the Gombong area are a new contribution to the understanding of paleoenvironmental change in the region, which in turn is important for understanding sea level change as well as climate change in the region.

  3. Post-Glacial and Paleo-Environmental History of the West Coast of Vancouver Island

    Science.gov (United States)

    Dallimore, A.; Enkin, R. J.

    2005-12-01

    Annually laminated sediments in anoxic fjords are potentially ideal paleoclimate recorders, particularly once proxy measurements for atmospheric, oceanographic and sedimentological conditions have been calibrated. On the west coast of Canada, these sediments also record the changing environment as glaciers retreated from this area about 12 ka y BP. In Effingham Inlet, a 40 m core taken from the French ship the Marion Dufresne as part of the international IMAGES/PAGES program, gives evidence of an isolation basin at maximum glacial isostatic rebound and lowest paleo-sea level followed by eustatic sea level rise about 10 ka y BP. The Late Pleistocene record also marks dramatic changes in glacial sedimentary source and transport. Excellent chronological control is provided by complementary yet independent dating methods including radiocarbon dates on both plants and shells, identification of the Mazama Ash, varve counting and paleomagnetic, paleosecular variation correlations in the lower, pro-glacial section of the core which does not contain organic material. Paleoenvironmental evidence from this core provides information on immediate post-glacial conditions along the coast and rapid climatic changes throughout the Holocene, with implications for the possibility of early human migration routes and refugia.

  4. Sedimentological and paleoenvironmental constraints of the Statherian and Stenian Espinhaço rift system, Brazil.

    OpenAIRE

    Santos, Marcelo Nascimento dos; Chemale Júnior, Farid; Dussin, Ivo Antonio; Martins, Maximiliano de Souza; Assis, Tiago A. R.; Jelinek, Andréa Ritter; Guadagnin, Felipe; Armstrong, Richard

    2013-01-01

    The Espinhaço Basin in eastern Brazil contains depositional sequences developed in the São Francisco paleoplate and its margins. Detailed mapping was conducted and combined with U–Pb detrital zircon dating to determine the sedimentological-stratigraphic framework, provenance and minimum and maximum ages of the syn-rift-deposits. The two cycles have minimum ages of 1192 and 923 Ma and maximum ages of 1785 and 1685 Ma. The first depositional cycle, represented by the Bandeirinha and São João da...

  5. Geologic, stratigraphic, thermal, and mechanical factors which influence repository design in the bedded salt environment

    International Nuclear Information System (INIS)

    Ashby, J.P.; Nair, O.; Ortman, D.; Rowe, J.

    1979-12-01

    This report describes the geologic, stratigraphic, thermal, and mechanical considerations applicable to repository design. The topics discussed in the report include: tectonic activity; geologic structure; stratigraphy; rock mechanical properties; and hydrologic properties

  6. Stratigraphic, regional unconformity analysis and potential petroleum plays of East Siberian Sea Basin

    Science.gov (United States)

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

    2017-04-01

    The East Siberian Sea basin (ESSB) one of the most unexplored part of the Russian Arctic shelf, extending for over 1000 km from New Siberian Islands archipelago to Wrangel Island. This region is considered as a region with probable high petroleum potential. Within the ESSB several phases of orogeny are recognized [1]: Elsmerian orogeny in Early Devonian, Early Brooks orogeny in Early Cretaceous, Late Brooks orogeny in Late Cretaceous. Two generations of the basins could be outlined. Both of these generations are controlled by the basement domains [1]: Paleozoic (post-Devonian) to Mesozoic basins preserved north of the Late Mesozoic frontal thrusts; Aptian-Albian to Quaternary basins, postdating the Verkhoyansk-Brookian orogeny, and evolving mainly over the New-Siberian-Chukchi Fold Belt. Basin is filled with siliclastic sediments and in the deepest depocentres sediments thickness exceeds 8-10 km in average. Seismic data was interpreted using methods of seismic stratigraphy. Finally, main seismic horizons were indicated and each horizon follows regional stratigraphic unconformities: mBU - in base of Cenozoic, BU - in base of Upper Cretaceous, LCU - in base of Cretaceous, JU - in middle of Jurassic, F - in top of Basement. In ESSB, we can identify Permian, Triassic, Jurassic, Cretaceous, Paleogene and Neogene seismic stratigraphy complexes. Perspective structures, investigated in ESSB were founded out by comparing seismogeological cross-sections with explored analogs in other onshore and offshore basins [2, 3, 4]. The majority of structures could be connected with stratigraphic and fault traps. The most perspective prospects are probably connected with grabens and depressions, where thickness of sediments exceed 10 km. Reservoirs in ESSB are proposed by regional geological explorations on New Siberian Islands Archipelago and Wrangel Island. Potential seals are predominantly assigned to Jurassic and Cretaceous periods. Thick clinoform units of various geometry and

  7. The Influence of Stratigraphic History on Landscape Evolution

    Science.gov (United States)

    Forte, A. M.; Yanites, B.; Whipple, K. X.

    2016-12-01

    Variation in rock erodibility can play a significant role in landscape evolution. Using a version of the CHILD landscape evolution model that allows for variations in rock erodibility, we found surprisingly complex landscape evolution in simulations with simple, two unit stratigraphies with contrasting erodibility. This work indicated that the stratigraphic order of units in terms of erodibility, the orientation of the contact with respect to the main drainage direction, and the contact dip angle all have pronounced effects on landscape evolution. Here we expand that work to explore the implications of more complicated stratigraphies on landscape evolution. Introducing multiple units adds additional controls on landscape evolution, namely the thicknesses and relative erodibility of rock layers. In models with a sequence of five alternating hard and soft units embedded within arbitrarily thick over- and underlying units, the number of individual layers that noticeably influence landscape morphology decreases as the thickness of individual layers reduces. Contacts with soft rocks over hard produce the most noticeable effect in model output such as erosion rate and channel steepness. For large contrasts in erodibility of 25 m thick layers, only one soft over hard contact is clearly manifest in the landscape. Between 50 and 75 m, two such contacts are manifest, and by 100 m thickness, all three of these contacts are manifest. However, for a given thickness of layers, more units are manifest in the landscape as the erodibility contrast between units decreases. This is true even though the magnitude of landscape effects away from steady-state erosion rates or channel steepness also decrease with decreasing erodibility contrast. Finally, we explore suites of models with alternating layers reflecting either `hardening-' or `softening-upwards' stratigraphies and find that the two scenarios result in decidedly different landscape forms. Hardening-upwards sections produce a

  8. Paleoenvironmental conditions at the loess paleosol sequence Bodrogkeresztúr in NE Hungary

    Science.gov (United States)

    Bösken, Janina; Obreht, Igor; Zeeden, Christian; Klasen, Nicole; Hambach, Ulrich; Sümegi, Pál; Lehmkuhl, Frank

    2017-04-01

    Loess paleosol sequences (LPS) have the ability to preserve past environmental and climatic conditions. Therefore, they are a widely used terrestrial archive for the reconstruction of paleoclimatic dynamics. In this study, we use several proxies (grain size distributions, geochemical analysis, rock magnetism, and color measurements) to study past environmental changes in a LPS covering the MIS 2/MIS 3 transition. Geochronological control is given by post infrared infrared stimulated luminescence dating of polymineral fine grains. The research aim lies in the reconstruction of the paleoenvironmental conditions at the loess-paleosol sequence Bodrogkeresztúr in northeastern Hungary using a multi-proxy approach. The sequence is located at the foot of the Kopasz hill, the southernmost part of the Tokaj Mountains, which belong to the Carpathian mountain range. The area is famous for the Bodrogkeresztúr-Henye Gravettian site (Lengyel, 2015). The profile contains eolian loess deposits intercalated by two paleosols. The lower paleosol overlays possibly fluvial clay (fine overbank deposits) forming the base of the profile. The luminescence samples have been tested thoroughly and have been measured with the pIR50IR290 protocol (Thiel et al., 2011). The final age assessment between 28.0±2.1 ka and 33.5±2.5 ka fits well to the established geochronologies of the Kopasz hill (Sümegi and Hertelendi, 1998) and the Tokaj section (Schatz et al., 2012). Paleoenvironmental conditions are investigated through the multi-proxy approach. The measurement of the anisotropy of magnetic susceptibility is interpreted in regard of paleowind directions. The magnetic susceptibility is enhanced in paleosols, especially in the lower one, indicating strong pedogenesis. Grain size parameters also show high clay contribution in the lower paleosol, but also indicate two distinct features of stronger wind dynamics in the loess layer in the middle of the profile (double sigmoidal fluctuations in all

  9. Paleoenvironmental conditions across the Jurassic-Cretaceous boundary in central-eastern Mexico

    Science.gov (United States)

    Martínez-Yáñez, Mario; Núñez-Useche, Fernando; López Martínez, Rafael; Gardner, Rand D.

    2017-08-01

    The Padni section of central-eastern Mexico is characterized by pelagic, organic-rich carbonates and shales dated in this study by calpionellid biostratigraphy to the late Tithonian-late Berriasian time interval. Microfacies, pyrite framboid size, spectrometric gamma-ray and mineralogical data are herein integrated in order to reconstruct the paleoenvironmental change during the Jurassic-Cretaceous boundary. Deposits of the late Tithonian-early Berriasian are characterized by laminated, organic-rich facies with abundant radiolarian, tiny pyrite framboids and low Th/U ratios. They are linked to upwelling in a semi-restricted basin, high marine productivity and anoxic bottom waters. The early incursions of Tethyan oceanic waters into the proto-Gulf of Mexico occurred during late Tithonian as attested the appearance of calpionellids. Short and intermittent accumulations of saccocomids during early Berriasian suggest episodes of sporadic connection between the Tethys, the proto-Atlantic and the Pacific ocean during sea-level rise events. A full and stable connection between the Tethys and proto-Gulf of Mexico was established until the late Berriasian. This event is supported by the presence of open marine and bioturbated facies with a framboid population typical of dysoxic conditions, higher Th/U ratios and a decreasing pattern of the total organic carbon content. In addition to highlighting the replenishment of the oxygen supply to the basin, this facies also points to a younger age for the finalization of the Yucatán Block rotation and the end of the Gulf of Mexico opening. Deposition of the studied section occurred mostly during a Tithonian-Berriasian arid phase reported in other Tethyan and Atlantic regions. The similarity between the discrete segments of the standard gamma-ray curve defined in the studied outcrop and those reported from subsurface implies their regional continuity allowing their use for correlation purposes.

  10. On the paleoenvironmental potential of 253 newly discovered pine stumps from Zurich, Switzerland

    Science.gov (United States)

    Reinig, Frederick; Nievergelt, Daniel; Esper, Jan; Friedrich, Michael; Helle, Gerhard; Hellmann, Lena; Kromer, Bernd; Morganti, Sandro; Pauly, Maren; Sookdeo, Adam; Tegel, Willy; Treydte, Kerstin; Wacker, Lukas; Büntgen, Ulf

    2017-04-01

    The transition from the last Ice Age to the early Holocene 15'000-10'000 BP represents a close natural analog to the ongoing and predicted rates of anthropogenic climate change. A reduced quality and quantity of high-resolution proxy archives during this period, however, limits our understanding of the magnitude and pace of Late Glacial (LG) environmental variability. Here, we present the world's best preserved, most replicated and oldest forest remains: A total of 253 subfossil pine stumps were recently discovered in Zurich. The combined approach of tree-ring and radiocarbon (14C) measurements results in an absolutely dated Preboreal Swiss tree-ring width chronology and eight floating chronologies. With tree ages ranging between 41 and 506 years, often including pith and bark, and a mean segment length of 163 years, this exceptional find is distributed over nearly 2'000 years between the Allerød and the Preboreal. Together with 200 previously collected LG pines from the greater Zurich region, this study sets a benchmark in terms of sample replication and dating precision for stable more dynamic climatic periods such as the Laacher See eruption, the Older and Younger Dryas. The paleoenvironmental significance would even increase when annually resolved 14C-measurements help fixing a major, Northern Hemispheric gap in the absolutely dated dendro time series during the Younger Dryas. While overcoming this interlude, our results further emphasize the importance of interdisciplinary research on these striking LG climatic shifts to better understand and assess their ecological and environmental impact.

  11. Paleoenvironmental and paleohydrochemical conditions of dolomite formation within a saline wetland in arid northwest Australia

    Science.gov (United States)

    Mather, Caroline C.; Skrzypek, Grzegorz; Dogramaci, Shawan; Grierson, Pauline F.

    2018-04-01

    Groundwater dolocrete occurring within the Fortescue Marsh, a large inland wetland in the Pilbara region of northwest Australia, has been investigated to provide paleoenvironmental and paleohydrological records and further the understanding of low temperature dolomite formation in terrestrial settings over the Quaternary Period. Two major phases of groundwater dolocrete formation are apparent from the presence of two distinct units of dolocrete, based on differences in depth, δ18O values and mineral composition. Group 1 (G1) occurs at depth 20-65 m b.g.l. (below ground level) and contains stoichiometric dolomite with δ18O values of -4.02-0.71‰. Group 2 (G2) is shallower (0-23 m b.g.l.), occurring close to the current groundwater level, and contains Ca-rich dolomite ± secondary calcite with a comparatively lower range of δ18O values (-7.74 and -6.03‰). Modelled δ18O values of paleogroundwater from which older G1 dolomite precipitated indicated highly saline source water, which had similar stable oxygen isotope compositions to relatively old brine groundwater within the Marsh, developed under a different hydroclimatic regime. The higher δ18O values suggest highly evaporitic conditions occurred at the Marsh, which may have been a playa lake to saline mud flat environment. In contrast, G2 dolomite precipitated from comparatively fresher water, and modelled δ18O values suggested formation from mixing between inflowing fresher groundwater with saline-brine groundwater within the Marsh. The δ18O values of the calcite indicates formation from brackish to saline groundwater, which suggests this process may be associated with coeval gypsum dissolution. In contrast to the modern hydrology of the Marsh, which is surface water dependent and driven by a flood and drought regime, past conditions conducive to dolomite precipitation suggest a groundwater dependent system, where shallow groundwaters were influenced by intensive evaporation.

  12. Molecular marker to identify radiolarian species -toward establishment of paleo-environmental proxy-

    Science.gov (United States)

    Ishitani, Y.

    2017-12-01

    Marine fossilized unicellular plankton are known to have many genetically divergent species (biological species) in the single morphological species and these biological species show the species-specific environments much more precisely than that of morphological species. Among these plankton, Radiolaria are one of the best candidates for time- and environmental-indicators in the modern and past oceans, because radiolarians are the only group which represent entire water column from shallow to deep waters. However, the ecology and evolution of radiolarian were traditionally studied in paleontology and paleoceanography by morphological species. Even Radiolaria has a huge potential for novel proxy of wide and deep environments, there is no criterion to identify the biological species. The motivation for this study is setting the quantitative delimitation to establish the biological species of radiolarians based on molecular data, for leading the future ecological and paleo-environmental study. Identification of the biological species by ribosomal DNA sequences are mainly based on two ways: one is the evolutionary distance of the small subunit (SSU) rDNA, the internal transcribed spacer region of ribosomal DNA (ITS1 and 2), and the large subunit (LSU) rDNA; and the other is the secondary structure of ITS2. In the present study, all four possible genetic markers (SSU, ITS1, ITS2, and LSU rDNA) were amplified from 232 individuals of five radiolarian morphological species and applied to examine the evolutionary distance and secondary structure of rDNA. Comprehensive survey clearly shows that evolutionary distance of ITS1 rDNA and the secondary structure of ITS2 is good to identify the species. Notably, evolutionary distance of ITS1 rDNA is possible to set the common delimitation to identify the biological species, as 0.225 substitution per site. The results show that the ITS1 and ITS 2 rDNA could be the criterion for radiolarian species identification.

  13. The Early Toarcian oceanic anoxic event: Paleoenvironmental and paleoclimatic change across the Alpine Tethys (Switzerland)

    Science.gov (United States)

    Fantasia, Alicia; Föllmi, Karl B.; Adatte, Thierry; Spangenberg, Jorge E.; Montero-Serrano, Jean-Carlos

    2018-03-01

    Paleoenvironmental and paleoclimatic change associated with the Toarcian oceanic anoxic event (T-OAE) was evaluated in five successions located in Switzerland. They represent different paleogeographic settings across the Alpine Tethys: the northern shelf (Gipf, Riniken and Rietheim), the Sub-Briançonnais basin (Creux de l'Ours), and the Lombardian basin (Breggia). The multi-proxy approach chosen (whole-rock and clay mineralogy, phosphorus, major and trace elements) shows that local environmental conditions modulated the response to the T-OAE across the Alpine Tethys. On the northern shelf and in the Sub-Briançonnais basin, high kaolinite contents and detrital proxies (detrital index, Ti, Zr, Si) in the T-OAE interval suggest a change towards a warmer and more humid climate coupled with an increase in the chemical weathering rates. In contrast, low kaolinite content in the Lombardian basin is likely related to a more arid climate along the southern Tethys margin and/or to a deeper and more distal setting. Redox-sensitive trace-element (V, Mo, Cu, Ni) enrichments in the T-OAE intervals reveal that dysoxic to anoxic conditions developed on the northern shelf, whereas reducing conditions were less severe in the Sub-Briançonnais basin. In the Lombardian basin well-oxygenated bottom water conditions prevailed. Phosphorus (P) speciation analysis was performed at Riniken and Creux de l'Ours. This is the first report of P speciation data for T-OAE sections, clearly suggesting that high P contents during this time interval are mainly linked to the presence of an authigenic phases and fish remains. The development of oxygen-depleted conditions during the T-OAE seems to have promoted the release of the organic-bound P back into the water column, thereby further sustaining primary productivity in a positive feedback loop.

  14. Paleoenvironmental inference models from sediment diatom assemblages in Baffin Island lakes (Nunavut, Canada) and reconstruction of summer water temperature

    Energy Technology Data Exchange (ETDEWEB)

    Joynt, E. H. III; Wolfe, A. P. [Colorado Univ., Inst. of Arctic and Alpine Research, Boulder, CO (United States)

    2001-06-01

    Lake sediments are attractive repositories for paleoclimate proxy data because they are temporally continuous, undisturbed and datable. It is particularly true of lakes which are ubiquitous throughout the Arctic regions, enabling dense spatial coverage of sampling sites. In more recent times diatoms have been applied to a a variety of paleoenvironmental questions. However, these studies have been of limited usefulness because they lack a regional training set that would facilitate making quantitative paleoenvironmental inferences. This article provides this inferential tool, together with an example of its application. Conductivity, pH, summer lake water temperature, and mean annual air temperature have been identified as the significant controls over diatom assemblages from the surface sediments of 61 lakes on Baffin Island. Using weighted-averaging regression and calibration, predictive models for these parameters have been developed. Results show that the summer lake water temperature model provides realistic reconstructions when compared with other paleoenvironmental records. Over the past 5000 years the amplitude of reconstructed summer lake water temperature was found to be on the order of 4 degrees C, expressed primarily as progressive neoglacial cooling culminating in the Little Ice Age. Diatom-inferred summer water temperatures have increased by about 2 degrees C in the past 150 years, which is also in agreement with independent paleoclimatic reconstructions. The data obtained in this study complements similar efforts from the western Canadian Arctic and the northern reaches of Scandinavia, however, this is the first training set developed for lakes situated entirely north of the tree line. As such, it extends the applicability of diatoms for paleotemperature reconstructions well into the Arctic tundra biome. 45 refs., 1 tab., 10 figs., 1 appendix.

  15. Student learning and understanding of sequence stratigraphic principles

    Science.gov (United States)

    Herrera, Juan Sebastian

    Research in geoscience education addressing students' conceptions of geological subjects has concentrated in topics such as geological time, plate tectonics, and problem solving in the field, mostly in K-12 and entry level college scenarios. Science education research addressing learning of sedimentary systems in advance undergraduates is rather limited. Therefore, this dissertation contributed to filling that research gap and explored students' narratives when explaining geological processes associated with the interaction between sediment deposition and sea level fluctuations. The purpose of the present study was to identify the common conceptions and alternative conceptions held by students when learning the basics of the sub discipline known as sequence stratigraphy - which concepts students were familiar and easily identified, and which ones they had more difficulty with. In addition, we mapped the cognitive models that underlie those conceptions by analyzing students' gestures and conceptual metaphors used in their explanations. This research also investigated the interaction between geoscientific visual displays and student gesturing in a specific learning context. In this research, an in-depth assessment of 27 students' ideas of the basic principles of sequence stratigraphy was completed. Participants were enrolled in advanced undergraduate stratigraphy courses at three research-intensive universities in Midwest U.S. Data collection methods included semi-structured interviews, spatial visualization tests, and lab assignments. Results indicated that students poorly integrated temporal and spatial scales in their sequence stratigraphic models, and that many alternative conceptions were more deeply rooted than others, especially those related to eustasy and base level. In order to better understand the depth of these conceptions, we aligned the analysis of gesture with the theory of conceptual metaphor to recognize the use of mental models known as image

  16. Paleoenvironmental reconstruction and evolution of an Upper Cretaceous lacustrine-fluvial-deltaic sequence in the Parecis Basin, Brazil

    Science.gov (United States)

    Rubert, Rogerio R.; Mizusaki, Ana Maria Pimentel; Martinelli, Agustín G.; Urban, Camile

    2017-12-01

    The Cretaceous in the Brazilian Platform records events of magmatism, tectonism and sedimentation coupled to the Gondwana breakup. Some of these events are registered as sedimentary sequences in interior basins, such as in the Cretaceous sequence of the Alto Xingu Sub-basin, Parecis Basin, Central Brazil. This article proposes the faciologic characterization and paleoenvironmental reconstruction of the Cretaceous sequence of the eastern portion of the Parecis Basin and its relation with some reactivated structures as, for instance, the Serra Formosa Arch. Based on both data from outcrops and core drillings a paleoenvironmental and evolutionary reconstruction of the sequence is herein presented. The base of the studied section is characterized by chemical and low energy clastic sedimentation of Lake Bottom and Shoreline, in a context of fast initial subsidence and low sedimentation rate. As the subsidence process decreased, a deltaic progradation became dominant with deposition in a prodelta environment, followed by a deltaic front and deltaic plain interbedded with fluvial plain, and aeolian deposition completing the sequence. The inferred Coniacian-Santonian age is based on vertebrate (fishes and notosuchians) and ostracod fossils with regional chrono-correlates in the Adamantina (Bauru Group), Capacete (Sanfranciscana Basin), and Bajo de la Carpa (Neuquén Group, in Argentina) formations. The formation of a Coniacian depocenter in the Alto Xingu Sub-basin is associated to the Turonian-Coniacian reactivation event in the Peruvian Orogenic Phase of the Andean Orogeny, with the transference of stresses to interplate setting, reactivating Proterozoic structures of the basement.

  17. Georeferenced historical forest maps of Bukovina (Northern Romania) - important tool for paleoenvironmental analyses

    Science.gov (United States)

    Popa, Ionel; Crǎciunescu, Vasile; Candrea, Bogdan; Timár, Gábor

    2010-05-01

    Austrian and Romanian forest surveyors, to correctly georeference the maps. A case study, demonstrating the usefulness of such old cartographic informations in understanding the forest landscape evolution is also included. The georeferenced map sheets provide an excellent basis of the paleo-environmental researches. Assessing the changes of the forest cover ratio is important for the analysis of the recent flash flood events at the eastern slopes of the Carpathian Mts.

  18. Paleoenvironmental reconstruction of the Oligocene-Miocene deposits of the Tethyan Seaway, Qom Formation, Central Iran

    Science.gov (United States)

    Dabaghi Sadr, Fatemeh; Schmiedl, Gerhard

    2017-04-01

    The Cenozoic climate transition from greenhouse to icehouse conditions was associated with major paleogeographic changes in the Tethyan realm. The closure of the Tethyan Seaway and its Iranian gateways during the terminal Paleogene and early Neogene, between approximately 28 and 18 million years, influenced the latitudinal exchange of water masses and energy and is documented in sediment successions of the Qom formation in central Iran. Little is known on the spatial expression and the exact depositional histories of the Qom Formation on orbital time-scales, including a lack of quantitative sea-level reconstructions and studies on the impact of climatic and tectonic changes on marine ecosystems and sedimentation processes. The PhD project focuses on the investigation of lithostratigraphy, biostratigraphy, paleoecology and paleoenvironmental evolution of the Iranian gateways based on late Oligocene to early Miocene foraminiferal faunas and carbonate facies from selected sediment sections of the Qom Basin. The Qom Formation was deposited in the Central Iranian back-arc basin during the Oligocene-Miocene. In this study foraminiferal faunas and carbonate microfacies were studied based on total 191 samples of two section of Qom Formation. One of them is Molkabad section, which is located northwest of Molkabad mountains, southeast of Garmsar. The section mainly consists of limestones, calcareous marls, marls, and gypsum-bearing marls with a total thickness of 760 meters. The Qom Formation at Molkabad section overlies Eocene rocks with an unconformity and consists of the following lithostratigraphic units (from the lower to upper part): Lithothamnium Limestone, Lower Marl Limestone, Bryozoa Limestone, and Upper Marl Group. The Molkabad fault separates the Qom Formation from the overlying Upper Red Formation. The other section is located at Navab anticline in Qom Formation .The section mainly consist of limestone, marl, and gypsum with a total thickness of 318 meters Navab

  19. Stratigraphic model deposit Ofi Inf SDZ-2X A1, Jun in block in Orinoco Oil belt

    International Nuclear Information System (INIS)

    Martinez, E.; Sandoval, D.

    2010-01-01

    This work is about the Stratigraphic model deposit O fi I nf SDZ-2X A1, Junin block in Orinoco Oil belt.This model was based on a chrono stratigraphic interpretation and was defined the correlation between the main and secondary surfaces. The wells of the study area pass through the Cambrian, Cretaceous and Miocene sediments. The last is more interesting for the study because of the stratigraphic and sand body surface presence

  20. Stratigraphic relations and hydrologic properties of the Paintbrush Tuff (PTn) hydrologic unit, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Moyer, T.C.; Geslin, J.K.; Flint, L.E.

    1996-01-01

    Yucca Mountain is being investigated as a potential site for a high- level nuclear waste repository. The intent of this study was to clarify stratigraphic relations within the Paintbrush Tuff (PTn) unit at Yucca Mountain in order to better understand vertical and lateral variations in hydrologic properties as they relate to the lithologic character of these rocks. This report defines informal stratigraphic units within the PTn interval, demonstrates their lateral continuity in the Yucca Mountain region, describes later and vertical variations within them, and characterizes their hydrologic properties and importance to numerical flow and transport models. We present tables summarizing the depth to stratigraphic contacts in cored borehole studies, and unit descriptions and correlations in 10 measured sections

  1. Stratigraphic relations and hydrologic properties of the Paintbrush Tuff (PTn) hydrologic unit, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Golden, CO (United States); Flint, L.E. [U.S. Geological Survey, Yucca Mountain Project, Mercury, NV (United States)

    1996-08-01

    Yucca Mountain is being investigated as a potential site for a high- level nuclear waste repository. The intent of this study was to clarify stratigraphic relations within the Paintbrush Tuff (PTn) unit at Yucca Mountain in order to better understand vertical and lateral variations in hydrologic properties as they relate to the lithologic character of these rocks. This report defines informal stratigraphic units within the PTn interval, demonstrates their lateral continuity in the Yucca Mountain region, describes later and vertical variations within them, and characterizes their hydrologic properties and importance to numerical flow and transport models. We present tables summarizing the depth to stratigraphic contacts in cored borehole studies, and unit descriptions and correlations in 10 measured sections.

  2. In the Land of the Sky: Recent Paleoenvironmental Research From Coastal Oaxaca, Mexico

    Science.gov (United States)

    Goman, M. F.; Joyce, A. A.; Mueller, R. G.

    2005-05-01

    The Lower Río Verde Valley of Oaxaca has had a long and complex cultural history in part shaped by significant landscape change that ocurred 2300 years ago, when the Río Verde river changed morphology from a meandering to a braided form. These changes were precipitated by anthropogenic landuse impacts in the highland valleys of Oaxaca over 125 linear km to the north. While the lower valley's geomorphic history is well studied, little is known of its paleoecology. In order to reconstruct the history of vegetation, climate, and associated land use change, sediment cores were raised from several sites throughout the region. We present stratigraphical, palynological, and charcoal data from three sites in the region. The lower drainage basin consists entirely of the Verde's coastal valley. The climate of the lower Río Verde Valley is hot and humid with mean annual rainfall of 1000 mm to 2000 mm and average temperatures range from 25°C to 28°C. We discuss the pollen and stratigraphic record from Laguna Pastoría which is a brackish estuary protected from the Pacific Ocean by a roughly east-west trending bay barrier. The bay barrier is about 500 m wide and 2 to 4 m high. Low scrub vegetation (cacti, thorny bushes, small trees and palms) grow on the barrier. The lagoon itself is approximately 9 km long and varies in depth with a 3-4 m maximum. Tides are microtidal (1 m). The lagoon supports a diverse array of mangroves (Rhizophora mangle, Laguncularia racemosa, Conocarpus erectus and Avicennia germinans). Two sediment cores were raised from the lagoon (LP1 and LP2) and provide a record of hurricane strikes and possible changes in the frequency of El Niño's. The LP1 core covers approximately the last 5000 yrs. Preliminary pollen analysis indicates that pollen is in excellent condition and is diverse (>60 taxa). Zea mays pollen was identified from sediments dating to the early Formative period (~ 3600 yr ago). The charcoal records analyzed from 2 paleomeanders of the

  3. Formation and distribution of large lithologic-stratigraphic oil & gas fields (provinces

    Directory of Open Access Journals (Sweden)

    Shizhen Tao

    2018-02-01

    Full Text Available Since the “Tenth Five-Year Plan”, lithologic and stratigraphic reservoirs have been the main contribution of both the discovery as well as reserve and production increase in China; there were about 80% of proven reserves. The typical reservoirs in six major basins in the eastern, central, and western China were adopted as reservoir forming models. The reservoir forming models in three types of slopes, three types of depressions, and three types of lithologic reservoir assemblages have been built on the basis of application of new technologies, physical modeling of reservoir forming mechanism, and investigation to the formation and distribution of the reservoirs. The evaluation methods for large lithologic reservoirs provinces were established based on the forming mechanism and main controlling factors mentioned above. In addition, the study reveals the main controlling factors and the laws of enrichment of two types of stratigraphic reservoirs (pinch-out and weathered karst reservoirs based on the evaluation methods for large stratigraphic reservoir provinces that have been established. By comprehensively understanding the laws of enrichment of lithologic-stratigraphic reservoirs in four types of basins, specific evaluation methods and fine exploration techniques have been developed. The findings led to an exploration direction in the “Thirteenth Five-Year Plan” period. The study supported the exploration and selection of oil and gas plays, as well as promoted the exploration of lithologic and stratigraphic reservoirs. Keywords: Lithologic trap, Stratigraphic trap, Lithostratigraphic reservoir, Large oil and gas field, Large oil and gas province, Formation and distribution, Exploration potential

  4. A preliminary guidebook for identifying stratigraphic contacts at the Nevada Test Site

    International Nuclear Information System (INIS)

    Pawloski, G.A.; McKague, H.L.; Wagoner, J.L.; McKinnis, W.B.

    1992-01-01

    Lithologic variation, regional depositional trends, and the lack of written guidelines have resulted in inconsistencies in the recognition of stratigraphic contacts in drill holes at the Nevada Test Site (NTS). Stratigraphic identification, based on mineralogy of discrete samples, can be augmented by geophysical logs and downhole movies to more accurately and consistently locate contacts between units. Criteria are established for locating the base of the Pahute Mesa ash-flow tuff, the top of the Ammonia Tanks ash-flow tuff, the top of the Ammonia Tanks bedded tuff, and the top and the base of the Rainier Mesa Tuff

  5. Stratigraphic Profiles for Selected Hanford Site Seismometer Stations and Other Locations

    Energy Technology Data Exchange (ETDEWEB)

    Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-02-01

    Stratigraphic profiles were constructed for eight selected Hanford Site seismometer stations, five Hanford Site facility reference locations, and seven regional three-component broadband seismometer stations. These profiles provide interpretations of the subsurface layers to support estimation of ground motions from past earthquakes, and the prediction of ground motions from future earthquakes. In most cases these profiles terminated at the top of the Wanapum Basalt, but at selected sites profiles were extended down to the top of the crystalline basement. The composite one-dimensional stratigraphic profiles were based primarily on previous interpretations from nearby boreholes, and in many cases the nearest deep borehole is located kilometers away.

  6. Large-Diameter Burrows of the Triassic Ischigualasto Basin, NW Argentina: Paleoecological and Paleoenvironmental Implications

    Science.gov (United States)

    Colombi, Carina E.; Fernández, Eliana; Currie, Brian S.; Alcober, Oscar A.; Martínez, Ricardo; Correa, Gustavo

    2012-01-01

    Large-diameter ichnofossils comprising three morphotypes have been identified in the Upper Triassic Ischigualasto and Los Colorados formations of northwestern Argentina. These burrows add to the global record of the early appearance of fossorial behavior during early Mesozoic time. Morphotypes 1 and 2 are characterized by a network of tunnels and shafts that can be assigned to tetrapod burrows given similarities with previously described forms. However, differences in diameter, overall morphology, and stratigraphic occurrence allow their independent classification. Morphotype 3 forms a complex network of straight branches that intersect at oblique angles. Their calcareous composition and surface morphology indicate these structures have a composite biogenic origin likely developed due to combined plant/animal interactions. The association of Morphotypes 1 and 2 with fluvial overbank lithologies deposited under an extremely seasonal arid climate confirms interpretations that the early appearance of burrowing behavior was employed by vertebrates in response to both temperature and moisture-stress associated with seasonally or perpetually dry Pangean paleoclimates. Comparisons of burrow morphology and biomechanical attributes of the abundant paleovertebrate fauna preserved in both formations permit interpretations regarding the possible burrow architects for Morphotypes 1 and 2. In the case of the Morphotype 1, the burrow constructor could be one of the small carnivorous cynodonts, Ecteninion or Probelesodon. Assigning an architect for Morphotype 2 is more problematic due to mismatches between the observed burrow morphology and the size of the known Los Colorados vertebrates. PMID:23227195

  7. Late Quaternary paleoenvironmental records from the Chatanika River valley near Fairbanks (Alaska)

    Science.gov (United States)

    Schirrmeister, Lutz; Meyer, Hanno; Andreev, Andrei; Wetterich, Sebastian; Kienast, Frank; Bobrov, Anatoly; Fuchs, Margret; Sierralta, Melanie; Herzschuh, Ulrike

    2016-09-01

    Perennially-frozen deposits are considered as excellent paleoenvironmental archives similar to lacustrine, deep marine, and glacier records because of the long-term and good preservation of fossil records under stable permafrost conditions. A permafrost tunnel in the Vault Creek Valley (Chatanika River Valley, near Fairbanks) exposes a sequence of frozen deposits and ground ice that provides a comprehensive set of proxies to reconstruct the late Quaternary environmental history of Interior Alaska. The multi-proxy approach includes different dating techniques (radiocarbon-accelerator mass spectrometry [AMS 14C], optically stimulated luminescence [OSL], thorium/uranium radioisotope disequilibria [230Th/U]), as well as methods of sedimentology, paleoecology, hydrochemistry, and stable isotope geochemistry of ground ice. The studied sequence consists of 36-m-thick late Quaternary deposits above schistose bedrock. Main portions of the sequence accumulated during the early and middle Wisconsin periods. The lowermost unit A consists of about 9-m-thick ice-bonded fluvial gravels with sand and peat lenses. A late Sangamon (MIS 5a) age of unit A is assumed. Spruce forest with birch, larch, and some shrubby alder dominated the vegetation. High presence of Sphagnum spores and Cyperaceae pollen points to mires in the Vault Creek Valley. The overlying unit B consists of 10-m-thick alternating fluvial gravels, loess-like silt, and sand layers, penetrated by small ice wedges. OSL dates support a stadial early Wisconsin (MIS 4) age of unit B. Pollen and plant macrofossil data point to spruce forests with some birch interspersed with wetlands around the site. The following unit C is composed of 15-m-thick ice-rich loess-like and organic-rich silt with fossil bones and large ice wedges. Unit C formed during the interstadial mid-Wisconsin (MIS 3) and stadial late Wisconsin (MIS 2) as indicated by radiocarbon ages. Post-depositional slope processes significantly deformed both, ground

  8. USA toetus Eestile

    Index Scriptorium Estoniae

    2007-01-01

    Ameerika Ühendriikide riigisekretär Condoleezza Rice kinnitas 3. mail 2007 telefonikõnes president Toomas Hendrik Ilvesele USA toetust Eestile ning tõsist muret Venemaa käitumise üle oma naaberriigi suhtes. Ilmunud ka: Meie Kodu 9. mai 2007, lk. 2, pealk.: USA riigisekretär Vabariigi Presidendile: Ühendriigid toetavad Eestit

  9. Glemmer USA Afghanistan nu?

    DEFF Research Database (Denmark)

    Jakobsen, Peter Viggo

    2015-01-01

    Hvis Obamas efterfølger kan skrue den rigtige strategiske fortælling sammen så vil USA ikke forlade Afghanistan med udgangen af 2016.......Hvis Obamas efterfølger kan skrue den rigtige strategiske fortælling sammen så vil USA ikke forlade Afghanistan med udgangen af 2016....

  10. Devonian and Lower Carboniferous Conodonts of the Cantabrian Mountains (Spain) and their stratigraphic application

    NARCIS (Netherlands)

    Adrichem Boogaert, van H.A.

    1967-01-01

    A short review of the literature on the stratigraphy of the Devonian and the Lower Carboniferous of the Cantabrian Mountains precedes the report of the author's stratigraphic and palaeontologic observations in León: the Río Esla area (Gedinnian to Viséan), the central Cantabrian area (Famennian to

  11. Ecology of non marine Ostracoda from la Fe reservoir (El Retiro, Antioquia) and their potential application in paleoenvironmental studies

    International Nuclear Information System (INIS)

    Saldarriaga, Andrea; Torres, Martinez Jose Ignacio.

    2010-01-01

    Littoral macrophytes from the La Fe reservoir (El Retiro, Antioquia) were sampled for ostracoda during June and September of 2008. This allowed the identification of four genera and six species of ostracoda belonging to the Cyprididae and Candonidae families, where Chlamydotheca and Cypridopsis were found to be the dominant genera. Chlamydotheca unispinosa was the most abundant species in the assemblage. Furthermore, the environmental variables: temperature, electric conductivity, dissolved oxygen, and pH were also measured, in order to establish their relation to ostracoda taxa, using Canonical Correspondence Analysis (CCA). Results confirm the cosmopolitan character of Cypridopsis vidua and evidence the importance of plant substrate on the occurrence and distribution of the Cyprididae family. The possible application of the recorded ostracoda assemblage in paleoenvironmental interpretations is discussed.

  12. Testing multivariate analysis in paleoenvironmental reconstructions using pollen records from Lagoa Salgada, NE Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Mauro B. de Toledo

    2009-12-01

    Full Text Available Despite the indisputable significance of identification of modern analogs for Paleoecology research, relatively few studies attempted to integrate modern and fossil samples on paleoenvironmental reconstructions. In Palynology, this general pattern is not different from other fields of Paleoecology. This study demonstrates the practical application of modern pollen deposition data on paleoenvironmental reconstructions based on fossil pollen by using multivariate analysis. The main goal of this study was to use Detrended Correspondence Analysis (DCA to compare pollen samples from two sediment cores collected at Lagoa Salgada, a coastal lagoon located at northeastern Rio de Janeiro State. Furthermore, modern surface samples were also statistically compared with samples from both cores, providing new paleoecological insights. DCA demonstrated that samples from both cores are more similar than previously expected, and that a strong pattern, related to a paleoenvironmental event, is present within the fossil data, clearly identifying in the scatter plot samples that represent pre- and post-environmental change. Additionally, it became apparent that modern vegetation and environmental conditions were established in this region 2500 years before present (BP. Multivariate Analysis allowed a more reliable integration of modern and fossil pollen data, proving to be a powerful tool in Paleoecology studies that should be employed more often on paleoclimate and paleoenvironmental reconstructions.Apesar da indiscutível importância da identificação de análogos modernos para estudos de Paleoecologia, relativamente poucos estudos procuraram integrar amostras modernas e fósseis em reconstruções paleoambientais. Na Palinologia este padrão não é diferente de outras áreas da Paleoecologia. Este estudo demonstra a aplicação prática de dados de deposição polínica atual em reconstruções paleoambientais baseadas em pólen fóssil utilizando an

  13. New tropical carcharhinids (chondrichthyes, carcharhiniformes) from the late Eocene early Oligocene of Balochistan, Pakistan: Paleoenvironmental and paleogeographic implications

    Science.gov (United States)

    Adnet, S.; Antoine, P.-O.; Hassan Baqri, S. R.; Crochet, J.-Y.; Marivaux, L.; Welcomme, J.-L.; Métais, G.

    2007-04-01

    New selachians (sharks and rays) have been collected from several late Eocene and early Oligocene marine localities in the Bugti Hills (Balochistan, Pakistan). Two new species of Requiem sharks (close to the Recent "Bull shark") are described : Carcharhinus balochensis and Carcharhinus perseus. The rest of the fauna is notable for the strong representation of Carcharhiniformes. These selachian faunas represent a unique tropical association for the Oligocene period and one of the first modern tropical selachian faunas, with modern taxa such as the two new species of "Bull sharks", Negaprion sp. and one of the first occurrences of Sphyrna sp. Moreover, these faunas permit paleoenvironmental interpretation of adjacent land masses. The relatively modern aspect of these faunas, compared with other contemporaneous and younger selachian associations from Atlantic and Mediterranean seas, suggests biogeographic isolation of selachian communities living in eastern and western parts of the Tethys before its final closure during the early-middle Miocene.

  14. SDAR 1.0 a New Quantitative Toolkit for Analyze Stratigraphic Data

    Science.gov (United States)

    Ortiz, John; Moreno, Carlos; Cardenas, Andres; Jaramillo, Carlos

    2015-04-01

    Since the foundation of stratigraphy geoscientists have recognized that data obtained from stratigraphic columns (SC), two dimensional schemes recording descriptions of both geological and paleontological features (e.g., thickness of rock packages, grain size, fossil and lithological components, and sedimentary structures), are key elements for establishing reliable hypotheses about the distribution in space and time of rock sequences, and ancient sedimentary environmental and paleobiological dynamics. Despite the tremendous advances on the way geoscientists store, plot, and quantitatively analyze sedimentological and paleontological data (e.g., Macrostrat [http://www.macrostrat.org/], Paleobiology Database [http://www.paleodb.org/], respectively), there is still a lack of computational methodologies designed to quantitatively examine data from a highly detailed SCs. Moreover, frequently the stratigraphic information is plotted "manually" using vector graphics editors (e.g., Corel Draw, Illustrator), however, this information although store on a digital format, cannot be used readily for any quantitative analysis. Therefore, any attempt to examine the stratigraphic data in an analytical fashion necessarily takes further steps. Given these issues, we have developed the sofware 'Stratigraphic Data Analysis in R' (SDAR), which stores in a database all sedimentological, stratigraphic, and paleontological information collected from a SC, allowing users to generate high-quality graphic plots (including one or multiple features stored in the database). SDAR also encompasses quantitative analyses helping users to quantify stratigraphic information (e.g. grain size, sorting and rounding, proportion of sand/shale). Finally, given that the SDAR analysis module, has been written in the open-source high-level computer language "R graphics/statistics language" [R Development Core Team, 2014], it is already loaded with many of the crucial features required to accomplish basic and

  15. Subsurface geology of the Lusi region: preliminary results from a comprehensive seismic-stratigraphic study.

    Science.gov (United States)

    Moscariello, Andrea; Do Couto, Damien; Lupi, Matteo; Mazzini, Adriano

    2016-04-01

    We investigate the subsurface data of a large sector in the Sidoarjo district (East Java, Indonesia) where the sudden catastrophic Lusi eruption started the 26th May 2006. Our goal is to understand the stratigraphic and structural features which can be genetically related to the surface manifestations of deep hydrothermal fluids and thus allow us to predict possible future similar phenomena in the region. In the framework of the Lusi Lab project (ERC grant n° 308126) we examined a series of densely spaced 2D reflection commercial seismic lines This allowed the reconstruction of the lateral variability of key stratigraphic horizons as well as the main tectonic features. In particular, we shed light on the deep structure of the Watukosek fault system and the associated fracture corridors crossing the entire stratigraphic successions. To the South-West, when approaching the volcanic complex, we could identify a clear contrast in seismic facies between chaotic volcanoclastic wedges and clastic-prone sedimentary successions as well as between the deeper stratigraphic units consisting of carbonates and lateral shales units. The latter show possible ductile deformation associated to fault-controlled diapirism which control in turns deformation of overlying stratigraphic units and deep geo-fluids circulation. Large collapse structures recognized in the study area (e.g. well PRG-1) are interpreted as the results of shale movement at depth. Similarly to Lusi, vertical deformation zones ("pipes"), likely associated with deeply rooted strike-slip systems seem to be often located at the interface between harder carbonate rocks forming isolated build ups and the laterally nearby clastic (shale-prone)-units. The mechanisms of deformation of structural features (strike vs dip slip systems) which may affect either the basement rock or the overlying deeper stratigraphic rocks is also being investigated to understand the relationship between deep and shallower (i.e. meteoric) fluid

  16. Appraising timing response of paleoenvironmental proxies to the Bond cycle in the western Mediterranean over the last 20 kyr

    Science.gov (United States)

    Rodrigo-Gámiz, Marta; Martínez-Ruiz, Francisca; Rodríguez-Tovar, Francisco J.; Pardo-Igúzquiza, Eulogio; Ortega-Huertas, Miguel

    2018-04-01

    The timing of climate responses to the Bond cycle is investigated in the western Mediterranean. Periodicities had been previously reported in a marine sediment record from this region spanning the last 20 kyr, and registered by diverse paleoenvironmental proxies, in particular those associated with terrigenous input, redox conditions, productivity, sea surface temperature (SST) and salinity. Further cross-spectral analyses on these time series reveal leads-lags in the 1400 year climate cycle. Considering as reference a terrigenous input proxy (the K/Al ratio), all the paleoenvironmental proxies displayed time shifts varying from ca. 700 year to ca. 350 year. SST and salinity variations show a first leaded response with the inflow of cold and less salty Atlantic waters. Followed by a time lead of 525 year, progresively arid conditions with an increase of eolian dust transport to the area, given by the Zr/Al signal, are observed. The intensification of dust transport could have triggered a latest biological response, lead by 350 year, with an increase of productivity, as suggested by the Ba/Al ratio. Lastly changes in the Mediterranean thermohaline circulation, indicated by a selected redox proxy (the U/Th ratio), are observed. These results support that the oceanic response triggered the atmospheric response to the Bond cycle in the western Mediterranean. Changes in the North Atlantic Oscillation mode and in the Inter-Tropical Convergence Zone migrations with variations in the monsoon activity or Saharan winds system, are considered as main forcing mechanisms, with a complex relationship of the involved phenomena.

  17. Stratigraphic inversion of pre-stack multicomponent data; Inversion stratigraphique multicomposante avant sommation

    Energy Technology Data Exchange (ETDEWEB)

    Agullo, Y.

    2005-09-15

    This thesis present the extension of mono-component seismic pre-stack data stratigraphical inversion method to multicomponent data, with the objective of improving the determination of reservoir elastic parameters. In addiction to the PP pressure waves, the PS converted waves proved their interest for imaging under gas clouds; and their potential is highly significant for the characterization of lithologies, fluids, fractures... Nevertheless the simultaneous use ol PP and PS data remains problematic because of their different the time scales. To jointly use the information contained in PP and PS data, we propose a method in three steps first, mono-component stratigraphic inversions of PP then PS data; second, estimation of the PP to PS time conversion law; third, multicomponent stratigraphic inversion. For the second point, the estimation of the PP to PS conversion law is based on minimizing the difference between the S impedances obtained from PP and PS mono-component stratigraphic inversion. The pre-stack mono-component stratigraphic inversions was adapted to the case of multicomponent data by leaving each type of data in its own time scale in order to avoid the distortion of the seismic wavelet. The results obtained on a realistic synthetic PP-PS case show on one hand that determining PP to PS conversion law (from the mono-component inversion results) is feasible, and on the other hand that the joint inversion of PP and PS data with this conversion law improves the results compared to the mono-component inversion ones. Although this is presented within the framework of the PP and PS multi-component data, the developed methodology adapts directly to PP and SS data for example. (author)

  18. Automated recognition of stratigraphic marker shales from geophysical logs in iron ore deposits

    Science.gov (United States)

    Silversides, Katherine; Melkumyan, Arman; Wyman, Derek; Hatherly, Peter

    2015-04-01

    The mining of stratiform ore deposits requires a means of determining the location of stratigraphic boundaries. A variety of geophysical logs may provide the required data but, in the case of banded iron formation hosted iron ore deposits in the Hamersley Ranges of Western Australia, only one geophysical log type (natural gamma) is collected for this purpose. The information from these logs is currently processed by slow manual interpretation. In this paper we present an alternative method of automatically identifying recurring stratigraphic markers in natural gamma logs from multiple drill holes. Our approach is demonstrated using natural gamma geophysical logs that contain features corresponding to the presence of stratigraphically important marker shales. The host stratigraphic sequence is highly consistent throughout the Hamersley and the marker shales can therefore be used to identify the stratigraphic location of the banded iron formation (BIF) or BIF hosted ore. The marker shales are identified using Gaussian Processes (GP) trained by either manual or active learning methods and the results are compared to the existing geological interpretation. The manual method involves the user selecting the signatures for improving the library, whereas the active learning method uses the measure of uncertainty provided by the GP to select specific examples for the user to consider for addition. The results demonstrate that both GP methods can identify a feature, but the active learning approach has several benefits over the manual method. These benefits include greater accuracy in the identified signatures, faster library building, and an objective approach for selecting signatures that includes the full range of signatures across a deposit in the library. When using the active learning method, it was found that the current manual interpretation could be replaced in 78.4% of the holes with an accuracy of 95.7%.

  19. Sequence stratigraphy in the middle Ordovician shale successions, mid-east Korea: Stratigraphic variations and preservation potential of organic matter within a sequence stratigraphic framework

    Science.gov (United States)

    Byun, Uk Hwan; Lee, Hyun Suk; Kwon, Yi Kyun

    2018-02-01

    The Jigunsan Formation is the middle Ordovician shale-dominated transgressive succession in the Taebaeksan Basin, located in the eastern margin of the North China platform. The total organic carbon (TOC) content and some geochemical properties of the succession exhibit a stratigraphically distinct distribution pattern. The pattern was closely associated with the redox conditions related to decomposition, bulk sedimentation rate (dilution), and productivity. To explain the distinct distribution pattern, this study attempted to construct a high-resolution sequence stratigraphic framework for the Jigunsan Formation. The shale-dominated Jigunsan Formation comprises a lower layer of dark gray shale, deposited during transgression, and an upper layer of greenish gray siltstone, deposited during highstand and falling stage systems tracts. The concept of a back-stepped carbonate platform is adopted to distinguish early and late transgressive systems tracts (early and late TST) in this study, whereas the highstand systems tracts and falling stage systems tracts can be divided by changes in stacking patterns from aggradation to progradation. The late TST would be initiated on a rapidly back-stepping surface of sediments and, just above the surface, exhibits a high peak in TOC content, followed by a gradually upward decrease. This trend of TOC distribution in the late TST continues to the maximum flooding surface (MFS). The perplexing TOC distribution pattern within the late TST most likely resulted from both a gradual reduction in productivity during the late TST and a gradual increase in dilution effect near the MFS interval. The reduced production of organic matter primarily incurred decreasing TOC content toward the MFS when the productivity was mainly governed by benthic biota because planktonic organisms were not widespread in the Ordovician. Results of this study will help improve the understanding of the source rock distribution in mixed carbonate

  20. The ANDRILL programme: a new multinational initiative to investigate Antarctica's climatic and tectonic history from stratigraphic drilling

    Science.gov (United States)

    Naish, T.; Andrill Steering Committee

    2003-04-01

    ANDRILL is a multinational initiative to investigate Antarctica’s role in Cenozoic-Recent (65 million years ago to the present) climatic, glacial and tectonic change through the recovery of stratigraphic records from and around the Antarctic margin. The ANDRILL programme was initially conceived and promoted by scientists who led the successful Cape Roberts Project (CRP) and other interested parties. A key motivation of ANDRILL is that the role of the Antarctic cryosphere (ice sheets, ice shelves and sea ice) in the climate system is complex and very poorly understood. While, high-quality sedimentary archives of past ice sheet behaviour have recently be-come available from projects such as the Cape Roberts Project and the Ocean Drilling Program (Leg 188, Prydz Bay), unfortunately they are too few in number to allow a comprehensive understanding of the continents influence on global climate. ANDRILL will address this issue through drilling a targeted portfolio of sites initially in the McMurdo Sound region. Here the dynamic behaviour of the East and West Antarctic ice sheets, and the Ross Ice Shelf have left their signature in the thick Cenozoic sedimentary fills of the West Antarctic Rift system and flexural moat basins. The ANDRILL McMurdo Sound Portfolio, is an 8 to 9 year programme spanning from 2001 to 2010 of which geophysical and site survey scientific investigations are nearing completion and the drilling phase will soon begin. An ANDRILL consortium has been established comprising five countries : USA, Italy, Germany, UK and NZ. This paper will present the scientific objectives of the programme, discuss the current status and future plans.

  1. USA kunstidessant Venemaale

    Index Scriptorium Estoniae

    2007-01-01

    USA kunstnike näitus "Kolm sajandit ameerika kunsti" Moskvas Pushkini muuseumis. Eksponeeritakse Mark Rothko, Jean-Michel Basguiat', Roy Lichtensteini, Robert Rauschenbergi, Georgia O'Keefe'i, Willem de Kooningi töid

  2. USA Hire Testing Platform

    Data.gov (United States)

    Office of Personnel Management — The USA Hire Testing Platform delivers tests used in hiring for positions in the Federal Government. To safeguard the integrity of the hiring processes and ensure...

  3. Contemporary sand wedge development in seasonally frozen ground and paleoenvironmental implications

    Science.gov (United States)

    Wolfe, Stephen A.; Morse, Peter D.; Neudorf, Christina M.; Kokelj, Steven V.; Lian, Olav B.; O'Neill, H. Brendan

    2018-05-01

    Contemporary sand wedges and sand veins are active in seasonally frozen ground within the extensive discontinuous permafrost zone in Northwest Territories, Canada. The region has a subarctic continental climate with 291 mm a-1 precipitation, -4.1 °C mean annual air temperature, warm summers (July mean 17.0 °C), and cold winters (January mean -26.6 °C). Five years of continuous observations indicate that interannual variation of the ground thermal regime is dominantly controlled by winter air temperature and snow cover conditions. At sandy sites, thin snow cover and high thermal conductivity promote rapid freezing, high rates of ground cooling, and low near-surface ground temperatures (-15 to -25 °C), resulting in thermal contraction cracking to depths of 1.2 m. Cracking potentials are high in sandy soils when air temperatures are air temperatures are ≤-17 °C, and snow cover is conditions in peatlands maintain permafrost, but thermal contraction cracking does not occur because thicker snow cover and the thermal properties of peat prolong freezeback and maintain higher winter ground temperatures. A combination of radiocarbon dating, optical dating, and stratigraphic observations were used to differentiate sand wedge types and formation histories. Thermal contraction cracks that develop in the sandy terrain are filled by surface (allochthonous) and/or host (autochthonous) material during the thaw season. Epigenetic sand wedges infilled with allochthonous sand develop within former beach sediments beneath an active eolian sand sheet. Narrower and deeper syngenetic wedges developed within aggrading eolian sand sheets, whereas wider and shallower antisyngenetic wedges developed in areas of active erosion. Thermal contraction cracking beneath vegetation-stabilized surfaces leads to crack infilling by autochthonous host and overlying organic material, with resultant downturning and subsidence of adjacent strata. Sand wedge development in seasonally frozen ground

  4. A paleoenvironmental study of subsurface Quaternary sediments at Wainuiomata, Wellington, New Zealand, and tectonic implications

    Energy Technology Data Exchange (ETDEWEB)

    Begg, J G; Mildenhall, D C; Lyon, G L; Stephenson, W R; Funnell, R H; Van Dissen, R J; Bannister, S; Brown, L J [Institute of Geological and Nuclear Sciences Ltd., Lower Hutt (New Zealand); Pillans, B; Harper, M A [Research School of Earth Sciences, Victoria University of Wellington, Wellington (New Zealand); Whitton, J [Manaaki Whenua - Landcare Research, Lower Hutt, (New Zealand)

    1994-12-31

    A stratigraphic drillhole (WS-1) sited on the floor of Wainuiomata Valley near Lower Hutt, revealed a 61.6 m thick Quaternary sequence overlying Torlesse Supergroup greywacke sandstone and argillite. The Quaternary sediments consist of three sequences separated by disconformities. The lower sequence, 10.7 m thick (61.6-50.9 m), consists of fluvial sediments of probable early Quaternary age. The middle sequence, about 48.3 m in thickness (50.9-c. 2.6 m), spans most of the Last Glaciation. Fluvial/overbnak (50.9-42.0 m), floodplain/swamp (42.9-34.5 m), and fluvial (34.5-31.3 m) sediments overlie the disconformity at 50.9 m. Conformably overlying these sediments are swamp and lacustrine deposits between 31.3 and 4.1 m. Diatoms and algal spores and coenobia show the existence of an extensive lake during much of this sequence, from 25.6 to 4.0 m. at the peak of its development, at a drillhole depth of c. 23 m, the lake was >10 m deep and had a high algal biomass. Kawakawa Tephra (22 600 yr b.p.) occurs near the top of the middle sequence at 4.1 m depth. The upper sequence, of Holocene-Recent age, is <2.6 m thick, including .06 m of fill. The existence of sediments of the lower sequence of at least Castlecliffian age (early Pleistocene) uncomformably overlying basement greywacke provides a minimum age for the K-surface in the area. The Last Glacial sediments show evidence of ponfing, which may be a result of one factor or a more of the following: ponding behind an aggradational terrace of the Wainuiomata River; landslide blockage of the Black Stream drainage near its confluence with Wainuiomata River; and tectonic deformation. Progressive tectonic deformation since the start of the Last Glaciation is considered the most likely dominant factor. This has resulted in the elevation of greywacke basement near the junction of Black Stream and Wainuiomata River. The nature of the deformation - faulting, tilting, and/or folding - has not been established. 38 refs,6 figs,2 tables.

  5. A paleoenvironmental study of subsurface Quaternary sediments at Wainuiomata, Wellington, New Zealand, and tectonic implications

    International Nuclear Information System (INIS)

    Begg, J.G.; Mildenhall, D.C.; Lyon, G.L.; Stephenson, W.R.; Funnell, R.H.; Van Dissen, R.J.; Bannister, S.; Brown, L.J.; Pillans, B.; Harper, M.A.; Whitton, J.

    1993-01-01

    A stratigraphic drillhole (WS-1) sited on the floor of Wainuiomata Valley near Lower Hutt, revealed a 61.6 m thick Quaternary sequence overlying Torlesse Supergroup greywacke sandstone and argillite. The Quaternary sediments consist of three sequences separated by disconformities. The lower sequence, 10.7 m thick (61.6-50.9 m), consists of fluvial sediments of probable early Quaternary age. The middle sequence, about 48.3 m in thickness (50.9-c. 2.6 m), spans most of the Last Glaciation. Fluvial/overbnak (50.9-42.0 m), floodplain/swamp (42.9-34.5 m), and fluvial (34.5-31.3 m) sediments overlie the disconformity at 50.9 m. Conformably overlying these sediments are swamp and lacustrine deposits between 31.3 and 4.1 m. Diatoms and algal spores and coenobia show the existence of an extensive lake during much of this sequence, from 25.6 to 4.0 m. at the peak of its development, at a drillhole depth of c. 23 m, the lake was >10 m deep and had a high algal biomass. Kawakawa Tephra (22 600 yr b.p.) occurs near the top of the middle sequence at 4.1 m depth. The upper sequence, of Holocene-Recent age, is <2.6 m thick, including .06 m of fill. The existence of sediments of the lower sequence of at least Castlecliffian age (early Pleistocene) uncomformably overlying basement greywacke provides a minimum age for the K-surface in the area. The Last Glacial sediments show evidence of ponfing, which may be a result of one factor or a combination of the following: ponding behind an aggradational terrace of the Wainuiomata River; landslide blockage of the Black Stream drainage near its confluence with Wainuiomata River; and tectonic deformation. Progressive tectonic deformation since about the start of the Last Glaciation is considered the most likely dominant factor. This has resulted in the elevation of greywacke basement near the junction of Black Stream and Wainuiomata River. The nature of the deformation - faulting, tilting, and/or folding - has not been established. (authors

  6. Rare earth element composition of Paleogene vertebrate fossils from Toadstool Geologic Park, Nebraska, USA

    Energy Technology Data Exchange (ETDEWEB)

    Grandstaff, D.E., E-mail: grand@temple.edu [Department of Earth and Environmental Science, Temple University, Philadelphia, PA 19122 (United States); Terry, D.O. [Department of Earth and Environmental Science, Temple University, Philadelphia, PA 19122 (United States)

    2009-04-15

    Fossil bones and teeth from terrestrial environments encode unique rare earth and trace element (REE and TE) signatures as a function of redox conditions, pH, concentrations of complexing ligands, and water-colloid interactions. This signature is set early in the fossilization process and serves as a paleoenvironmental and paleoclimatic proxy. These signatures can also be used to interpret temporal and spatial averaging within vertebrate accumulations, and can help relocate displaced fossil bones back into stratigraphic context. Rare earth elements in vertebrate fossils from upper Eocene and Oligocene strata of Toadstool Geologic Park, northwestern Nebraska, record mixing and evolution of Paleogene vadose or groundwaters and variations in paleoenvironments. REE signatures indicate that HREE-enriched alkaline groundwater reacted with LREE- and MREE-enriched sediments to produce 3-component mixtures. REE signatures become increasingly LREE- and MREE-enriched toward the top of the studied section as the paleoenvironment became cooler and drier, suggesting that REE signatures may be climate proxies. Time series analysis suggests that REE ratios are influenced by cycles of ca. 1050, 800, 570, 440, and 225 ka, similar to some previously determined Milankovitch astronomical and climate periodicities.

  7. Stable isotope (δ"1"3C and δ"1"5N) based interpretation of organic matter source and paleoenvironmental conditions in Al-Azraq basin, Jordan

    International Nuclear Information System (INIS)

    Ahmad, Khaldoun; Davies, Caroline

    2017-01-01

    This study examines the stable isotopes of carbon and nitrogen from cored lacustrine sediments of the Al-Azraq, an arid lake basin on the Jordan Plateau. Lacustrine sediments contain valuable records of paleoenvironmental conditions, recording local and regional responses to environmental change. Previous paleo-reconstructions on the Jordan Plateau are based on archaeology, pollen, mineralogy, and stratigraphy. The application of organic geochemistry analyses to these lake sediments identifies multiple sources of organic matter, biological production, and contributes to understanding the paleoenvironments of the Al-Azraq basin during the mid-Pleistocene period. Organic carbon concentration (Corg) provides an overview of the organic matter distribution. Carbon isotopic composition (δ13Corg) and nitrogen isotopic composition (δ15N) are indicators of organic matter sources and paleoproductivity. Magnetic susceptibility (MGSUS) measured the concentration of ferromagnetic minerals and indicated aeolian inputs. Organic geochemistry differentiated five paleoenvironmental zones with specific sources of organic matter, both aquatic and terrestrial. It identified a long period of climate wetter than the present, punctuated by a short intense period of aridity. Diagenesis plays an important role in the decomposition of organic matter and studies indicate this degradation can alter the isotopic signals of organic matter. Analyses of the isotopic signals and statistical analyses demonstrate diagenesis is not a factor in the Al-Azraq sediments in all but Zone 4 of the paleoenvironmental zones. This Zone is defined by less negative carbon isotopic composition and the presence of thick primary gypsum layers, in addition to the influx of high peaks of aeolian sediment as reflected in the magnetic susceptibility data. Stable isotope geochemistry provides detailed information on the paleoenvironments of lake sediments, and is applicable to typically challenging arid basin sediments

  8. Selected stratigraphic data for drill holes located in Frenchman Flat, Nevada Test Site. Rev. 1

    International Nuclear Information System (INIS)

    Drellack, S.L. Jr.

    1997-02-01

    Stratigraphic data are presented in tabular form for 72 holes drilled in Frenchman Flat, Nevada Test Site, between 1950 and 1993. Three pairs of data presentations are included for each hole: depth to formation tops, formation thicknesses, and formation elevations are presented in both field (English) and metric units. Also included for each hole, where available, are various construction data (hole depth, hole diameter, surface location coordinates) and certain information of hydrogeologic significance (depth to water level, top of zeolitization). The event name is given for holes associated with a particular nuclear test. An extensive set of footnotes is included, which indicates data sources and provides other information. The body of the report describes the stratigraphic setting of Frenchman Flat, gives drill-hole naming conventions and database terminology, and provides other background and reference material

  9. Stratigraphic and tectonic revision of Cerro Olivo Complex located of Southeastern of Uruguay

    International Nuclear Information System (INIS)

    Masquelin, E.

    2004-01-01

    This paper presents a stratigraphic and tectonic revision of Cerro Olivo Complex, located in the Southeastern part of the Uruguayan Predevonian Shield. This informal lithostratigraphic unit constitutes the country rock for the emplacement of late-orogenic granitoids, during Neoproterozoic to Cambrian times. This unit groups all the lithodemes affected by deformation and metamorphism. Recent studies indicate the presence of straight gneisses of quartzo-feldspathic composition in the coast of Maldonado Department. These rocks were interpreted as the result of intense deformation in high temperature. These tectonites base a new stratigraphic insight for the complex. They allow their lithotypes to be organized by petrotectonic features, being a function of PT conditions for every last strain process [es

  10. Geoarchaeologic and paleopedologic evidences for the holocene paleoenvironmental evolution of the Crisuri plain (Western Romania

    Directory of Open Access Journals (Sweden)

    Nicolae Josan

    2007-12-01

    Full Text Available This study is based mainly on the correlation established between the fossil soils identified within several archaeological sites from Crisuri Plain as well as the information that could be obtained by analysing their content in artefacts and paleozoological remains and takes into account the validity of some consecrated points of view, almost unanimously accepted concerning the paleoenvironmental evolution of the North Western part of Romania. Some very popular "clichés" such as the supposition of the warm and pregnant humid climate during the Atlantic period, fact which determined the wide spreading of the forests or that explains the appearance of the steppe and forest-steppe elements as a result of an intense deforestation process, seems to be contested by paleopedologic and geoarchaelogic arguments that prove the existence of several periods of climatic optimum separated by paleoenvironmental crisis periods.L'étude a pour objectif de préciser l'évolution holocène des secteurs inférieurs de la Plaine de Crişuri, domaine marqué par des mouvements de subsidence et par une tectonique encore active. La méthode utilisée s'appuie sur les relations entre différents éléments : les sols fossiles dans lesquels ont été trouvés des fragments de céramiques dont l'appartenance culturelle et de l'âge peuvent être déterminés à l'aide des méthodes archéologiques ; le rapport spatial entre les sites archéologiques et les facteurs géomorphologiques ; les données des recherches paléobotaniques et paléozoologiques existantes ; les connaissances sur les sols fossiles dont des profils représentatifs sont décrits dans des études récentes sur l'évolution holocène des paysages de la Plaine de la Transylvanie ; les travaux récents sur la reconstruction paléoenvironnementale de l'Holocène supérieur de l'Europe Centrale.Les sites contenant des vestiges de plusieurs périodes successives sont nombreux dans la plaine de Cri

  11. Repeated fault rupture recorded by paleoenvironmental changes in a wetland sedimentary sequence ponded against the Alpine Fault, New Zealand

    Science.gov (United States)

    Clark, K.; Berryman, K. R.; Cochran, U. A.; Bartholomew, T.; Turner, G. M.

    2010-12-01

    At Hokuri Creek, in south Westland, New Zealand, an 18 m thickness of Holocene sediments has accumulated against the upthrown side of the Alpine Fault. Recent fluvial incision has created numerous exposures of this sedimentary sequence. At a decimetre to metre scale there are two dominant types of sedimentary units: clastic-dominated, grey silt packages, and organic-dominated, light brown peaty-silt units. These units represent repeated alternations of the paleoenvironment due to fault rupture over the past 7000 years. We have located the event horizons within the sedimentary sequence, and identified evidence to support earthquake-driven paleoenvironmental change (rather than climatic variability), and developed a model of paleoenvironmental changes over a typical seismic cycle. To quantitatively characterise the sediments we use high resolution photography, x-ray imaging, magnetic-susceptibility and total carbon analysis. To understand the depositional environment we used diatom and pollen studies. The organic-rich units have very low magnetic susceptibility and density values, with high greyscale and high total carbon values. Diatoms indicate these units represent stable wetland environments with standing water and predominantly in-situ organic material deposition. The clastic-rich units are characterised by higher magnetic susceptibility and density values, with low greyscale and total carbon. The clastic-rich units represent environments of flowing water and deep pond settings that received predominantly catchment-derived silt and sand. The event horizon is located at the upper contact of the organic-rich horizons. The event horizon contact marks a drastic change in hydrologic regime as fault rupture changed the stream base level and there was a synchronous influx of clastic sediment as the catchment responded to earthquake shaking. During the interseismic period the flowing-water environment gradually stabilised and returned to an organic-rich wetland. Such

  12. The distribution of organic carbon fractions in a typical loess-paleosol profile and its paleoenvironmental significance

    Directory of Open Access Journals (Sweden)

    Qingqing Zhang

    2018-04-01

    Full Text Available Background The loess-paleosol sequence on the Loess Plateau has been considered an important paleoclimatic archive to study global climatic and environmental changes in the Quaternary. So far, little attention has been paid to the characteristics of soil organic carbon fractions in loess-paleosol sequences, which may provide valuable information for exploring the evolution of climate and environment in the Quaternary on the Loess Plateau. Methods In order to explore the significance of mineral-associated organic carbon to total organic carbon (MOC/TOC ratios in the loess-paleosol sequence for reconstructing paleoenvironmental and paleoclimatic evolution in the Quaternary on the Loess Plateau, we selected a typical loess-paleosol profile in Chunhua county, Xianyang city, Shaanxi province, as the research object. The content of total organic carbon (TOC and MOC/TOC ratio in each loess and paleosol layers of the Chunhua loess-paleosol profile were analyzed, together with the paleoclimatic proxies, such as soil grain size, CaCO3 content and their correlations with organic carbon parameters. Results The main results were as follows: (1 the total content of soil organic carbon and MOC/TOC ratios were generally higher in paleosol layers than in the underlying loess layers of the Chunhua loess-paleosol profile. Compared to total organic carbon content, MOC/TOC ratios changed more obviously in soil layers below a paleosol layer S8; (2 soil clay content and median grain size (Md (ϕ were higher in paleosol than in the underlying loess, while CaCO3 content showed an opposite tendency. In the Chunhua profile, the distribution characteristics of the three paleoclimatic proxies showed good indications of paleoclimate changes in the Quaternary; (3 in the Chunhua loess-paleosol profile, MOC/TOC ratios were positively correlated with clay content and median grain size (ϕ, while negatively correlated with CaCO3 content, and the correlations were more significant

  13. The distribution of organic carbon fractions in a typical loess-paleosol profile and its paleoenvironmental significance

    Science.gov (United States)

    Hu, Feinan; Huo, Na; Shang, Yingni; Chang, Wenqian

    2018-01-01

    Background The loess-paleosol sequence on the Loess Plateau has been considered an important paleoclimatic archive to study global climatic and environmental changes in the Quaternary. So far, little attention has been paid to the characteristics of soil organic carbon fractions in loess-paleosol sequences, which may provide valuable information for exploring the evolution of climate and environment in the Quaternary on the Loess Plateau. Methods In order to explore the significance of mineral-associated organic carbon to total organic carbon (MOC/TOC) ratios in the loess-paleosol sequence for reconstructing paleoenvironmental and paleoclimatic evolution in the Quaternary on the Loess Plateau, we selected a typical loess-paleosol profile in Chunhua county, Xianyang city, Shaanxi province, as the research object. The content of total organic carbon (TOC) and MOC/TOC ratio in each loess and paleosol layers of the Chunhua loess-paleosol profile were analyzed, together with the paleoclimatic proxies, such as soil grain size, CaCO3 content and their correlations with organic carbon parameters. Results The main results were as follows: (1) the total content of soil organic carbon and MOC/TOC ratios were generally higher in paleosol layers than in the underlying loess layers of the Chunhua loess-paleosol profile. Compared to total organic carbon content, MOC/TOC ratios changed more obviously in soil layers below a paleosol layer S8; (2) soil clay content and median grain size (Md (ϕ)) were higher in paleosol than in the underlying loess, while CaCO3 content showed an opposite tendency. In the Chunhua profile, the distribution characteristics of the three paleoclimatic proxies showed good indications of paleoclimate changes in the Quaternary; (3) in the Chunhua loess-paleosol profile, MOC/TOC ratios were positively correlated with clay content and median grain size (ϕ), while negatively correlated with CaCO3 content, and the correlations were more significant in soil

  14. Revised Cretaceous and Tertiary stratigraphic nomenclature in the Colville Basin, Northern Alaska

    Science.gov (United States)

    Mull, Charles G.; Houseknecht, David W.; Bird, Kenneth J.

    2003-01-01

    A revised stratigraphic nomenclature is proposed for Cretaceous and Tertiary geologic units of the central and western North Slope of Alaska. This revised nomenclature is a simplified and broadly applicable scheme suitable for a suite of digital geologic quadrangle maps being prepared jointly by the U.S. Geological Survey and the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas. This revised nomenclature scheme is a simplification of a complex stratigraphic terminology that developed piecemeal during five decades of geologic investigations of the North Slope. It is based on helicopter-supported geologic field investigations incorporating information from high-resolution aerial photography, satellite imagery, paleontology, reflection seismic records, and sequence stratigraphic concepts. This revised nomenclature proposes the abandonment of the Colville Group; demotion of the Nanushuk Group to formation status; abandonment of six formations (Kukpowruk, Tuktu, Grandstand, Corwin, Chandler, and Ninuluk); revision of four formations (Sagavanirktok, Prince Creek, Schrader Bluff, and Seabee); elevation of the Tuluvak Tongue of the Prince Creek Formation to formation status; revision of two members (Franklin Bluffs Member and Sagwon Member of the Sagavanirktok Formation); abandonment of eight members or tongues (Kogosukruk, Rogers Creek, Barrow Trail, Sentinel Hill, Ayiyak, Shale Wall, Niakogon, and Killik); and definition of one new member (White Hills Member of the Sagavanirktok Formation).

  15. Salt Repository Project site study plan for stratigraphic boreholes: Revision 1, December 18, 1987

    International Nuclear Information System (INIS)

    1987-01-01

    This site study describes the Stratigraphic Boreholes field work to be conducted during the early stages of Site Characterization at the Deaf Smith County, Texas site. The field program has been designed to provide data useful in addressing information/data needs resulting from Federal/State/local regulations, and repository program requirements. Four Stratigraphic Holes will be drilled near the perimeter of the site to document the subsurface geologic conditions in that area and to provide data necessary for design and construction of the Exploratory Shaft Facilities. Continuous samples will be recovered from the ground surface to the total depth of each sell. Geophysical well logs will provide additional coverage of the stratigraphic section. In-situ down hole testing will include short term hydrologic tests and hydraulic fracture tests to provide information on deep groundwater characteristics and regional stress patterns, respectively. Field methods/tests are chosen that provide the best or only means of obtaining the required data. The Salt Repository Project (SRP) Networks specify the schedule which the program will operate. The Technical Services Contractor is responsible for conducting the field program of drilling and testing. Samples and data will be handled and reported in accordance with established SRP procedures. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that the appropriate documentation is maintained. 30 refs., 13 figs., 4 tabs

  16. A method of reconstructing complex stratigraphic surfaces with multitype fault constraints

    Science.gov (United States)

    Deng, Shi-Wu; Jia, Yu; Yao, Xing-Miao; Liu, Zhi-Ning

    2017-06-01

    The construction of complex stratigraphic surfaces is widely employed in many fields, such as petroleum exploration, geological modeling, and geological structure analysis. It also serves as an important foundation for data visualization and visual analysis in these fields. The existing surface construction methods have several deficiencies and face various difficulties, such as the presence of multitype faults and roughness of resulting surfaces. In this paper, a surface modeling method that uses geometric partial differential equations (PDEs) is introduced for the construction of stratigraphic surfaces. It effectively solves the problem of surface roughness caused by the irregularity of stratigraphic data distribution. To cope with the presence of multitype complex faults, a two-way projection algorithm between threedimensional space and a two-dimensional plane is proposed. Using this algorithm, a unified method based on geometric PDEs is developed for dealing with multitype faults. Moreover, the corresponding geometric PDE is derived, and an algorithm based on an evolutionary solution is developed. The algorithm proposed for constructing spatial surfaces with real data verifies its computational efficiency and its ability to handle irregular data distribution. In particular, it can reconstruct faulty surfaces, especially those with overthrust faults.

  17. Tectonic-stratigraphic evolution of Cumuruxatiba Basin - Brazil; Evolucao tectono-estratigrafica da Bacia de Cumuruxatiba

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, Gustavo; Fernandes, Flavio L.; Silva, Eric Zagotto; Ferreira Neto, Walter Dias [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem Multidisciplinar de Bacias Sedimentares; Ribeiro, Juliana [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Brasilia, DF (Brazil)

    2008-07-01

    In recent years, the exploratory interest on Cumuruxatiba Basin has been inconstant, with modest discoveries of oil. Aiming to deepen the geological knowledge of the basin and in order to attract the interest of oil companies, the ANP (National Agency of Petroleum, Natural Gas and Biofuels) signed contract with COPPE/UFRJ for carrying out an analysis basin project. The project was developed by the Basin Analysis Multidisciplinary Modeling Laboratory (Lab2M/UFRJ) in the period 2006/2007, and was with the main objective outline the main structural and seismo-stratigraphic features of the basin, and in an integrated and multidisciplinary way, build a model of its sedimentation and tectono-stratigraphic evolution. This paper presents the results of the regional seismic mapping, aided by well and potential methods data. The stratigraphic succession the basin has been divided into genetic units (UN-B, UN-C e UN-D) corresponding to second order depositional sequences, they are: UN-B, corresponding by a rift and sag-rift siliciclastic deposits, plus the Aptian evaporitic deposits; UN-C, characterized by carbonatic deposits, and shelf related sediments; and UN-D, corresponding by a final transgressive (siliciclastic) - regressive (mix) cycle, between Cenomanian and actual days. (author)

  18. Paleoenvironmental change in the southern Kenya Rift System: A case study based on the Pleistocene Olorgesailie and Oltulelei Formations

    Science.gov (United States)

    Behrensmeyer, A. K.; Potts, R.; Deino, A. L.

    2017-12-01

    The Pleistocene paleoenvironmental history of the East African Rift in southern Kenya is recorded by the Olorgesailie Fm. (1.2 - 0.5 ma) and the overlying Oltulelei Fm. ( 320 ka - 50 ka), which occur in a depositional basin north of Mt. Olorgesailie that extends into the northern end of the Koora Graben west of the mountain. The two formations preserve abundant archeological sites and fossil remains that document hominin behavior and paleoecology during the time in Africa when Homo erectus evolved into Homo sapiens. Geochronological calibration, based primarily on Ar-Ar dates of interbedded tephras, shows shifts in the physical landscape on time scales of 104 - 105 yrs, with a prolonged period of primarily lacustrine deposition (Olorgesailie Fm.) followed by tectonically driven changes in base level leading to accelerating cycles of erosion and deposition (Oltulelei Fm.). Following major erosion of the Olorgesailie Fm. between 500 and 320 ka, the Oltulelei Fm. was deposited during three cycles of aggradation and erosion, with fluvial, lacustrine and wetlands deposits preserved in fault-controlled areas or temporarily blocked drainage valleys. Deposition occurred in three sub-basins with varying degrees of linkage, reflecting a changing balance of sediment input and accommodation space controlled by climate, volcanism, and periodic movement of faults in the volcanic basement. Large volumes of sediment were removed during erosive phases, requiring increased precipitation and through-flowing drainage into Koora Graben southwest and south of Mt. Olorgesailie. The southern Kenya rift provided a shifting array of habitats and environmental challenges for hominins, which were driven both by the dynamic tectonic setting and climate cycles. Portions of both the Olorgesailie and Oltulelei Fms. correlate geochronologically with a drill core record 20 km to the south (ODP-OLO12-1A), which will provide paleoclimate information for times when erosion and subaerial landscapes

  19. The Alleret Maar lacustrine sequence (French Massif Central): a 150 ka long early-middle Pleistocene continental paleoenvironmental record.

    Science.gov (United States)

    Nomade, S.; Pastre, J.; Guillou, H.; Gauthier, A.; Scaillet, S.

    2008-12-01

    Lacustrine maar sequences of the French Massif Central are of great interest for paleoclimatic and paleoenvironmental reconstructions of mid-latitudes Quaternary continental environments. In particular, the western Velay region yields exceptional sequences spanning the last 450 ka (Reille et al., J. Quat. Sci. 2000). However, older sequences remain largely unknown despite the presence of interbedded alkaline tephras allowing precise absolute radiochronological control of many lacustrine squences. The Alleret maar is a 1500 m wide phreatomagmatic crater that provides a long lacustrine sequence (41 m). The upper part of this sequence (AL2 core, 14.6 m) was studied between 2005 and 2006 (Pastre et al., C. R. Acad Sci, 2007). A 39Ar/40Ar date (557 ± 5ka) obtained from an interbedded tephra layer located at 7m as well as the associated pollen data attribute the beginning of this sequence to the MIS 15. Thanks to the AL3 core recovered in 2005 (40.6 m, CNRS Meudon) several new tephra layers were discovered in the bottom part of this lacustrine sequence. Three new 39Ar/40Ar ages (single crystal analyses) from trachytic tephra layers were obtained at the LSCE Argon Laboratory (France). These layers are located at -30.2, -36.2 and -39.2m. Ages obtained relative to the ACR-2 flux standard (1,201Ma, Kuiper et al., Science, 2008) range from 692 ± 6 ka (MSWD: 2.3, n=18) for the youngest (-30.2m) to 726 ± 9Ka Ka (MSWD: 2.2, n=12) for the lowest tephra located at -39.2m. These new dates indicate a relatively homogeneous deposition rate of 3.5cm/ka and that the last 10 meters cover the MIS 17-MIS18 period. According to these current radiochronological data the complete lacustrine sequence last more than 150ka. Ongoing sedimentary and pollen studies will allow to extend the paleoenvironmental and paleoclimatic records of the French Massif Central towards the beginning of the early middle Pleistocene.

  20. Stable isotopes in modern ostrich eggshell: a calibration for paleoenvironmental applications in semi-arid regions of southern Africa

    Science.gov (United States)

    Johnson, Beverly J.; Fogel, Marilyn L.; Miller, Gifford H.

    1998-07-01

    An isotopic study of modern ostrich eggshell (OES) is presented as a calibration for terrestrial paleoenvironmental applications. The stable carbon and nitrogen isotope fractionations of OES were determined for various organic fractions of eggshell by measuring the isotopic ratios of modern OES samples collected from controlled settings (i.e., zoos and farms) and corresponding ostrich diet. These fractionations were used to evaluate the relationship between the isotope composition of OES laid by free-range birds living in South Africa and their environment. The carbon isotope composition of the total organic and inorganic fractions of OES were enriched by 2 and 16‰, respectively, relative to the diet. In natural settings, the δ 13C values of both the organic and inorganic fractions of OES reflected that of ambient vegetation, with a noted dietary preference for C 3 plants. The nitrogen isotope composition of the total organic fraction of OES was 3‰ enriched relative to the diet, and varied inversely with mean annual precipitation (MAP) in natural settings. A decrease in MAP of 100 mm was accompanied by an increase in δ 15N values of approximately 1‰. The oxygen isotope composition of the inorganic fraction of the OES varied linearly with that of the drinking water in controlled settings. However, in natural settings, the δ 18O of OES values were highly variable and are thought to be controlled primarily by the δ 18O of ingested plant leaf-water. The stability of the isotopic signal in the organic fraction of OES through geologic time was evaluated through a series of heating experiments. The δ 13C and δ 15N values of the total organic fraction of heated OES increased by less than 0.6 and 0.2‰ for carbon and nitrogen, respectively, in spite of extensive diagenetic alteration and changes in the amino acid composition of the samples. The results of this study indicate that the stable carbon and nitrogen isotope composition of OES is relatively stable

  1. Det sorte USA

    DEFF Research Database (Denmark)

    Brøndal, Jørn

    Bogen gennemgår det sorte USAs historie fra 1776 til 2016, idet grundtemaet er spændingsforholdet mellem USAs grundlæggelsesidealer og den racemæssige praksis, et spændingsforhold som Gunnar Myrdal kaldte "det amerikanske dilemma." Bogen, der er opbygget som politisk, social og racemæssig histori......, er opdelt i 13 kapitler og består af fire dele: Første del: Slaveriet; anden del: Jim Crow; tredje del. King-årene; fjerde del: Frem mod Obama....

  2. Paleoenvironmental evolution of the coastal plain of Southern Brazil: palynological data from a Holocene core in Santa Catarina State

    Directory of Open Access Journals (Sweden)

    LIDIA A. KUHN

    2017-10-01

    Full Text Available ABSTRACT This paper presents a paleoenvironmental reconstruction from palynological analyses of a sedimentary core of Holocene age, drilled at municipality of Garopaba (Santa Catarina, Southern Brazil. A total of 46 samples was collected for palynological analyses in the 450 cm-long core PCSC-3, as also three samples for radiocarbon dating and granulometric analyses. The palynological content includes 84 taxa related to pollen grains of angiosperms (38 and gimnosperm (3, spores of pteridophyta (16 and bryophyta (2, spores of fungi (8, algae (3, acritarchs (3, dinoflagellate cysts (2 and microforaminiferal linings (1. Three specimens of acritarchs are described and illustrated in detail. Three palynological phases were defined based on changes in assemblages: Phase I, Phase II and Phase III. The Phase I is characterized as a lagoonal paleoenvironment with marine influence from the beginning of the sedimentation (5390 cal yr BP, based on occurrences of acritarchs, dinoflagellate cysts and microforaminiferal linings. The Phase II (3032 yr BP until 858 cal yr BP also is characterized by a lagoonal paleoenvironment, however, presented decrease in percentage of marine elements and increase in freshwater algae record, suggesting less marine influence in the lagoonal body. In Phase III (last 856 years, underwater sedimentation prevailed, under swamp-like conditions.

  3. Facies analysis and paleoenvironmental reconstruction of Upper Cretaceous sequences in the eastern Para-Tethys Basin, NW Iran

    Energy Technology Data Exchange (ETDEWEB)

    Omidvar, M.; Safari, A.; Vaziri-Moghaddam, H.; Ghalavand, H.

    2016-07-01

    Upper Cretaceous mixed carbonate-siliciclastic sequences are among the most important targets for hydrocarbon exploration in the Moghan area, located in the eastern Para-Tethys Basin. Despite of their significance, little is known about their facies characteristics and depositional environments. Detailed facies analysis and paleoenvironmental reconstruction of these sequences have been carried out in eight surface sections. Accordingly, four siliciclastic facies, eight carbonate facies and one volcanic facies have been recognized. Detailed facies descriptions and interpretations, together with the results of facies frequency analysis, standard facies models and Upper Cretaceous depositional models of Para-Tethys Basin, have been integrated and a non-rimmed carbonate platform is presented. This platform was affected by siliciclastic influx, in the form of coastal fan delta and submarine fans in the shallow- to deep-marine parts, respectively. This model is interpreted to be shallower in the central and northeastern parts of the Moghan area. Toward the southeast and southwest, this shallow platform turns into deep marine settings along steep slopes without remarkable marginal barriers. (Author)

  4. Revised paleoenvironmental analysis of the Holocene portion of the Barbados sea-level record: Cobbler's Reef revisited

    Science.gov (United States)

    Toscano, Marguerite A.

    2016-06-01

    Sample elevations corrected for tectonic uplift and assessed relative to local modeled sea levels provide a new perspective on paleoenvironmental history at Cobbler's Reef, Barbados. Previously, 14C-dated surface samples of fragmented Acropora palmata plotted above paleo sea level based on their present (uplifted) elevations, suggesting supratidal rubble deposited during a period of extreme storms (4500-3000 cal BP), precipitating reef demise. At several sites, however, A. palmata persisted, existing until ~370 cal BP. Uplift-corrected A. palmata sample elevations lie below the western Atlantic sea-level curve, and ~2 m below ICE-6G-modeled paleo sea level, under slow rates of sea-level rise, negating the possibility that Cobbler's Reef is a supratidal storm ridge. Most sites show limited age ranges from corals likely damaged/killed on the reef crest, not the mixed ages of rubble ridges, strongly suggesting the reef framework died off in stages over 6500 yr. Reef crest death assemblages invoke multiple paleohistoric causes, from ubiquitous hurricanes to anthropogenic impacts. Comparison of death assemblage ages to dated regional paleotempestological sequences, proxy-based paleotemperatures, recorded hurricanes, tsunamis, European settlement, deforestation, and resulting turbidity, reveals many possible factors inimical to the survival of A. palmata along Cobbler's Reef.

  5. Middle to Late Eocene paleoenvironmental changes in a marine transgressive sequence from the northern Tethyan margin (Adelholzen, Germany)

    Science.gov (United States)

    GEBHARDT, Holger; ĆORIĆ, Stjepan; DARGA, Robert; BRIGUGLIO, Antonino; SCHENK, Bettina; WERNER, Winfried; ANDERSEN, Nils; SAMES, Benjamin

    2015-01-01

    The northern Tethyan margin is a key region for determining environmental changes associated with the collision of continental and oceanic tectonic plates and Alpine orogeny. Herein we investigated Middle to Late Eocene neritic to bathyal sediments deposited during an interval of unstable climatic conditions. In order to quantify paleoenvironmental changes, we developed a detailed age model based on biozonations of planktic foraminifera, calcareous nannoplankton, and larger benthic foraminifera. The section at Adelholzen covers the almost complete Lutetian Stage (calcareous nannoplankton zones NP15a-16, planktic foraminifera zones E8-11, shallow benthic (foraminifera) zones SBZ13-15) and large parts of the Priabonian Stage (NP18-20, E14/15), while the intermediate Bartonian Stage (NP17) is completely missing. Foraminiferal, calcareous nannoplankton, and macrofossil assemblages were analyzed for changes in paleo-water depth, mixing and stratification, paleo-primary productivity (pPP), food supply, and bottom water oxygenation. Paleo-water depth estimates range from 50 m (middle neritic, early Lutetian) to nearly 500 m (upper bathyal, late Priabonian). The combination of assemblage composition, planktic and benthic foraminiferal accumulation rates, and derived parameters (carbon-flux to sea floor, pPP) enabled us to identify a series of distinct paleoceanographic events of at least regional significance. Such events are characterized by considerable changes in primary productivity or reduced bottom water ventilation. Calculated pPP-values indicate oligotrophic conditions throughout. PMID:26346423

  6. BRACKISH MARSH BENTHIC MICROFAUNA AND PALEOENVIRONMENTAL CHANGES DURING THE LAST 6000 YEARS AT THE COASTAL PLAIN OF MARATHON (SE GREECE

    Directory of Open Access Journals (Sweden)

    MARIA V.TRIANTAPHYLLOU

    2003-11-01

    Full Text Available The present study, based mainly on the analysis of foraminifers and ostracodes, provides evidence of paleoenvironmental changes on the coastal plain of Marathon (E. Greece during the last 6.000 yrs. Three sedimentary units -lagoonal formations - were recognized and identified as A, B and C. They range in time between before 5500BP-3500BP, 3500BP-2500BP and 2500BP-recent, respectively. The study of the brackish marsh microfauna of the Marathon plain Holocene sediments reveals the presence, during the last 5500 yrs., of three distinct biofacies in the sedimentary units already established. Alternating mesohaline - oligohaline (MO, oligohaline - fresh water (OFW and mesohaline - oligohaline to oligohaline - fresh water (MO-OFW biofacies in the framework of the sedimentary units indicate a general trend landward along the plain suggesting a slowing of sea-level rise probably correlated with a relevant tectonic uplift. One prominent feature of this study is the clarification of the ecological preference of the species Trichohya1us aguayoi (Bermudez, 1935, which is dominant in oligohaline conditions under an influence of fresh water input (salinity less than 15 ‰. 

  7. Baltimaade kunsti turnee USAs

    Index Scriptorium Estoniae

    1998-01-01

    5. nov.-st USA Lõuna-Carolina osariigis Wellington B. Grey galeriis ja Jenkins Fine Art Center's 13 eesti, läti ja leedu kunstniku näitus, mis hakkab kolme aasta jooksul ringlema Ameerikas. Eksponeeritud fotokunst, video, installatsioon, joonistused. Kuraator Peeter Linnap ja Mari Laanemets peavad ettekande näituse avamisega samal ajal toimuval Fotohariduse Ühingu konverentsil

  8. Stratigraphic condensation of marine transgressive records: Origin of major shell deposits in the Miocene of Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Kidwell, S.M. (Univ. of Chicago, IL (USA))

    1989-01-01

    Cyclic stratigraphic sequences in shallow marine records are commonly charaterized by a condensed transgressive lag at the base of thicker, shallowing-upward facies. The standard actualistic model for these thin fossiliferous lags, by which most of the shelf is starved owing to coastal trapping of sediment and fossils are suspected of being reworked because of the association with an erosional ravinement, is contradicted by detailed stratigraphic and taphonomic analysis of Miocene examples in the Maryland coastal plain. The complex internal stratigraphies of the shell deposits and the mixture of soft- and shell-bottom faunas indicate condensation under a regime of dynamic bypassing rather than complete sediment starvation; bypassed fine sediments accumulated in deeper water environments below storm wavebase. Deeper, even more basinward parts of the shelf were starved of all sediment size fractions and accumulated shell-poor, bone-rich condensed deposits that lie mid-cycle (bracketing the time of maximum water depth). The base-of-cycle shell deposits and mid-cycle bone bed differ not only in composition and in environment and dynamics of condensation, but also in chronostratigraphic value: the onlapping shell deposits must be diachronous to some degree, whereas the mid-cycle bone bed approximates an isochronous marker for correlation. Thus, in some settings at least, transgressive shelves present a spatial mosaic of condensational and depositional regimes. Regardless of origin, all condensed intervals can time-average assemblages and telescope biostratigraphic datums. They otherwise differ widely, however, in paleontologic attributes and are characterized by highly variable and complex stratigraphic anatomies.

  9. Tectonic evolution of the Paranoá basin: New evidence from gravimetric and stratigraphic data

    Science.gov (United States)

    Martins-Ferreira, Marco Antonio Caçador; Campos, José Eloi Guimarães; Von Huelsen, Monica Giannoccaro

    2018-06-01

    Field gravimetric and stratigraphic surveys were conducted with the aim to constraint the mechanisms responsible for the initiation of the Stenian-Tonian Paranoá basin, central Brazil, a subject not yet studied in detail. The Paranoá Group crops out in the external zone of the Brasília Belt, a Neoproterozoic orogen in the western margin of the São Francisco Craton. Detailed geological mapping confirmed the existence of a regional scale fault that controlled sedimentation of the Paranoá Group during the deposition of its basal formations, revealing important details about basin initiation and early evolution. Gravimetric modeling indicates the existence of paleorift structures beneath the Paranoá sequence in the study area. Results from both stratigraphic and gravimetric surveys show strong evidence of mechanical subsidence by faulting during basin initiation. Unsorted, angular, clasts cut by quartz veins and brecciated boulders present in the basal conglomerate, support this hypothesis. Basin initiation faults coincide with deeper paleorift faults and are thus interpreted as reactivations of the older Statherian Araí Rift. The reactivations favored an initial regime of mechanical subsidence, dominated by the development of epirogenic arches subsiding at different rates. Apart from faulting activity, the post-basal sequence presents no evidence of rift environment in the strict sense. Besides, the great lateral continuity and relatively constant thickness of facies, indicate that an initial mechanic subsidence rapidly gave way to flexural subsidence during subsequent stages of basin evolution. The Paranoá Group do not present reliable characteristics that would allow its strict classification as a passive margin. Its main stratigraphic characteristics, tectonic location and basement architecture, indicate that the Paranoá Group was deposited in a cratonic margin basin, and may have been either connected to a passive margin basin at times of sea level rise

  10. Stratigraphic evidence of desertification in the west-central Great Plains within the past 1000 yr

    Science.gov (United States)

    Madole, R.F.

    1994-01-01

    Stratigraphic and geomorphic relations, archaeological data, and eight radiocarbon ages at five widely scattered localities in northeastern Colorado indicate that eolian sand was mobilized over broad areas within the past 1000 yr. The mobilization began after 1 ka, was episodic, and ended at some as yet undetermined time prior to the latter part of the 19th century. Given that climate-model simulations suggest only slight variation in average surface temperature and annual precipitation in this region during the past 1000 yr, this part of the Great Plains evidently is near the threshold of widespread eolian sand transport under the present climate. -Author

  11. Neogene and Quaternary geology of a stratigraphic test hole on Horn Island, Mississippi Sound

    Science.gov (United States)

    Gohn, Gregory S.; Brewster-Wingard, G. Lynn; Cronin, Thomas M.; Edwards, Lucy E.; Gibson, Thomas G.; Rubin, Meyer; Willard, Debra A.

    1996-01-01

    During April and May, 1991, the U.S. Geological Survey (USGS) drilled a 510-ft-deep, continuously cored, stratigraphic test hole on Horn Island, Mississippi Sound, as part of a field study of the Neogene and Quaternary geology of the Mississippi coastal area. The USGS drilled two new holes at the Horn Island site. The first hole was continuously cored to a depth of 510 ft; coring stopped at this depth due to mechanical problems. To facilitate geophysical logging, an unsampled second hole was drilled to a depth of 519 ft at the same location.

  12. The stratigraphic distribution of large marine vertebrates and shell beds in the Pliocene of Tuscany

    Science.gov (United States)

    Dominici, Stefano; Benvenuti, Marco; Danise, Silvia

    2015-04-01

    The record of 337 shark fossils, 142 cetaceans and 10 sea cows from the Pliocene of Tuscany, mostly from historical museum collections, is revised. The majority of these fossils are concentrated at a few geographic sites from separated hinterland basins, on the South-Western side of the Northern Apennines. To better understand the meaning of these concentrations, the sequence stratigraphic distribution of more recent findings of large marine vertebrates is reconstructed against a high-resolution framework based on sedimentary facies analysis. These remains are usually covered by, or included in mudstones deposited far from the coast (N=12), skeletons being usually articulated, slightly displaced, and often bioeroded. A minor part of better preserved articulated skeletons is associated with sandstones from deltaic paleonenvironments (N=2). Marine mammal and shark remains may be associated with laterally-continuous shell accumulations, a type of concentration occurring at maximum flooding surfaces, separating relatively coarse-grained facies from open marine mudstones. Shell beds were bulk-sampled at 66 locations from six basins, covering a wide range of sedimentary facies, and spanning a chronologic interval of about 2.5 million years. A dataset of 62,655 mollusc specimens belonging to 496 species formed the basis of a statistical study to reconstruct the structure of the benthic communities, and to estimate paleodepths from intertidal to upper bathyal settings. Mollusc associations closely mirror the distribution of sedimentary facies, allowing for a fine tuning of the sequence stratigraphic architecture. Merging paleogeographic, stratigraphic and paleoecologic data, we conclude that the more abundant and diverse accumulations of large vertebrates took place in settings under the influence of coastal upwelling. A modern analogue occurs today in the Ligurian Sea, on the Tuscan offshore, where abundant nutrients carried by deep-marine currents of Western origin

  13. Full 3-D stratigraphic inversion with a priori information: a powerful way to optimize data integration

    Energy Technology Data Exchange (ETDEWEB)

    Grizon, L.; Leger, M.; Dequirez, P.Y.; Dumont, F.; Richard, V.

    1998-12-31

    Integration between seismic and geological data is crucial to ensure that a reservoir study is accurate and reliable. To reach this goal, there is used a post-stack stratigraphic inversion with a priori information. The global cost-function combines two types of constraints. One is relevant to seismic amplitudes, and the other to an a priori impedance model. This paper presents this flexible and interpretative inversion to determine acoustic impedances constrained by seismic data, log data and geologic information. 5 refs., 8 figs.

  14. Guantanamo rikub USA seadusi / Krister Paris

    Index Scriptorium Estoniae

    Paris, Krister, 1977-

    2003-01-01

    Kaks USA tsiviilkohut leiavad oma otsuses, et USA valitsus rikub USA-s ja Guantanamo sõjaväebaasis kinnipeetavate nn. vaenlasvõitlejate õigusi. Inimõigusorganisatsioonid avaldavad heameelt kohtute otsuste üle

  15. A three-dimensional stratigraphic model for aggrading submarine channels based on laboratory experiments, numerical modeling, and sediment cores

    Science.gov (United States)

    Limaye, A. B.; Komatsu, Y.; Suzuki, K.; Paola, C.

    2017-12-01

    Turbidity currents deliver clastic sediment from continental margins to the deep ocean, and are the main driver of landscape and stratigraphic evolution in many low-relief, submarine environments. The sedimentary architecture of turbidites—including the spatial organization of coarse and fine sediments—is closely related to the aggradation, scour, and lateral shifting of channels. Seismic stratigraphy indicates that submarine, meandering channels often aggrade rapidly relative to lateral shifting, and develop channel sand bodies with high vertical connectivity. In comparison, the stratigraphic architecture developed by submarine, braided is relatively uncertain. We present a new stratigraphic model for submarine braided channels that integrates predictions from laboratory experiments and flow modeling with constraints from sediment cores. In the laboratory experiments, a saline density current developed subaqueous channels in plastic sediment. The channels aggraded to form a deposit with a vertical scale of approximately five channel depths. We collected topography data during aggradation to (1) establish relative stratigraphic age, and (2) estimate the sorting patterns of a hypothetical grain size distribution. We applied a numerical flow model to each topographic surface and used modeled flow depth as a proxy for relative grain size. We then conditioned the resulting stratigraphic model to observed grain size distributions using sediment core data from the Nankai Trough, offshore Japan. Using this stratigraphic model, we establish new, quantitative predictions for the two- and three-dimensional connectivity of coarse sediment as a function of fine-sediment fraction. Using this case study as an example, we will highlight outstanding challenges in relating the evolution of low-relief landscapes to the stratigraphic record.

  16. Greigite formed in early Pleistocene lacustrine sediments from the Heqing Basin, southwest China, and its paleoenvironmental implications

    Science.gov (United States)

    Qiang, Xiaoke; Xu, Xinwen; Zhao, Hui; Fu, Chaofeng

    2018-05-01

    The ferrimagnetic iron sulfide greigite (Fe3S4) occurs widely in sulfidic lacustrine and marine sedimentary environments. Knowledge of its formation and persistence is important for both magnetostratigraphic and paleoenvironmental studies. Although the formation mechanism of greigite has been widely demonstrated, the sedimentary environments associated with greigite formation in lakes, especially on relatively long timescales, are poorly understood. A long and continuous sequence of Pleistocene lacustrine sediments was recovered in the Heqing drill core from southwestern China, which provides an outstanding record of continental climate and environment. Integrated magnetic, geochemical, and paleoclimatic analysis of the lacustrine sequence provides an opportunity to improve our understanding of the environmental controls on greigite formation. Rock magnetic and scanning electron microscope analyses of selected samples from the core reveal that greigite is present in the lower part of the core (part 1, 665.8-372.5 m). Greigite occurs throughout this interval and is the dominant magnetic mineral, irrespective of the climatic state. The magnetic susceptibility (χ) record, which is mainly controlled by the concentration of greigite, matches well with variations in the Indian Summer Monsoon (ISM) index and total organic carbon (TOC) content, with no significant time lag. This indicates that the greigite formed during early diagenesis. In greigite-bearing intervals, with the χ increase, Bc value increase and tends to be stable at about 50 mT. Therefore, we suggest that χ values could estimate the variation of greigite concentration approximately in the Heqing core. Greigite favored more abundant in terrigenous-rich and organic-poor layers associated with weak summer monsoon which are characterized by high χ values, high Fe content, high Rb/Sr ratio and low TOC content. Greigite enhancement can be explained by variations in terrigenous inputs. Our studies demonstrate

  17. Neoproterozoic–Cambrian stratigraphic framework of the Anti-Atlas and Ouzellagh promontory (High Atlas), Morocco

    Science.gov (United States)

    Alvaro, Jose Javier; Benziane, Fouad; Thomas, Robert; Walsh, Gregory J.; Yazidi, Abdelaziz

    2014-01-01

    In the last two decades, great progress has been made in the geochronological, chrono- and chemostratigraphic control of the Neoproterozoic and Cambrian from the Anti-Atlas Ranges and the Ouzellagh promontory (High Atlas). As a result, the Neoproterozoic is lithostratigraphically subdivided into: (i) the Lkest-Taghdout Group (broadly interpreted at c. 800–690 Ma) representative of rift-to-passive margin conditions on the northern West African craton; (ii) the Iriri (c. 760–740 Ma), Bou Azzer (c. 762–697 Ma) and Saghro (c. 760?–610 Ma) groups, the overlying Anezi, Bou Salda, Dadès and Tiddiline formations localized in fault-grabens, and the Ouarzazate Supergroup (c. 615–548 Ma), which form a succession of volcanosedimentary complexes recording the onset of the Pan-African orogeny and its aftermath; and (iii) the Taroudant (the Ediacaran–Cambrian boundary lying in the Tifnout Member of the Adoudou Formation), Tata, Feijas Internes and Tabanite groups that have recorded development of the late Ediacaran–Cambrian Atlas Rift. Recent discussions of Moroccan strata to select new global GSSPs by the International Subcommissions on Ediacaran and Cambrian Stratigraphy have raised the stratigraphic interest in this region. A revised and updated stratigraphic framework is proposed here to assist the tasks of both subcommissions and to fuel future discussions focused on different geological aspects of the Neoproterozoic–Cambrian time span.

  18. Geochemical evaluation of a shale stratigraphic profile from Paraiba Valley (Tremembe)

    International Nuclear Information System (INIS)

    Loureiro, M.R.B.; Cardoso, J.N.

    1987-01-01

    The sedimentary core ranges 0-35m depth and covers three types of bituminous shales, intercalated by two layers of sterile clay. A systematic geochemical study of samples of most stratigraphic layers was undertaken for the first time in this work, including elemental analysis (C, H), carbonate content, type of organic matter, infrared spectrometry and molecular characterization of organic extracts (hight-resolution) gas chromatography, mass spectrometry). No consistent correlation between lithology and amount/type of organic matter was observed, contrary to literature data, pointing out the paper shale strata as richest in organic matter. Molecular stratigraphy of the core presented similar n-alkane profiles generally maximizing at n-C 27 attesting to a small variation in input along the sedimentary section. Characterization of the branched/cyclic hydrocarbons evidenced a continental input to the sediment, as revealed by the presence, in several layers, of isometric des-A-fernenes, presumed products of diagenesis of arborinone. A microbial input was also evidenced through the general occurrence of hopanoids, trace amounts of steroidal skeletons as well as atomic H/C ratios ca. 2. The sharp variations in biomarker profiles with depth showed great potential as correlation markers in a detailed stratigraphic study of the basin, as a valuable supplement to traditional lithological parameters. (author) [pt

  19. Genetic and stratigraphic significance of the Upper Devonian Frasnian Z Marker, west-central Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Wendte, J. [Geological Survey of Canada, Calgary, AB (Canada); Stoakes, F. [Stoakes Consulting Group Ltd., Calgary, AB (Canada); Bosman, M. [Canadian Hunter Exploration Ltd., Calgary, AB (Canada); Bernstein, L. [Talisman Energy Inc., Calgary, AB (Canada)

    1995-12-01

    The stratigraphic model from the west-central Alberta basin was provided. It defined the Z Marker as a distinctive and widespread wireline log marker within the thick Frasnian Ireton shale basin succession. The marker represents an interval of condensed sedimentation and corresponds to an abrupt change from a calcareous signature below to an argillaceous character above. Toward the shelf, in the West Pembina area, the Z Marker correlates to a level within a conformable succession of nodular lime wackestones and corresponds to the base of a depositional cycle near the middle of the Lobstick member of the Nisku Formation. Further shelfward, the Z Marker continues as a well-defined log marker until the Nisku shelf margin. The stratigraphic significance of the Z Marker in delineating various oil bearing formations in Alberta were explained in great detail. The correct recognition and correlation of this marker was claimed to permit an understanding of basin evolution beyond that discernable from the existing lithostratigraphic nomenclature alone. 17 refs., 13 figs.

  20. 14C dating of the Early to Late Bronze Age stratigraphic sequence of Aegina Kolonna, Greece

    International Nuclear Information System (INIS)

    Wild, E.M.; Gauss, W.; Forstenpointner, G.; Lindblom, M.; Smetana, R.; Steier, P.; Thanheiser, U.; Weninger, F.

    2010-01-01

    Aegina Kolonna, located in the center of the Saronic Gulf in the Aegean Mediterranean (Greece), is one of the major archaeological sites of the Aegean Bronze Age with a continuous stratigraphic settlement sequence from the Late Neolithic to the Late Bronze Age. Due to its position next to the maritime cross roads between central mainland Greece, the northeast Peloponnese, the Cyclades and Crete, the island played an important role in the trade between these regions. In the course of new excavations, which focused on the exploration of the Early, Middle and Late Bronze Age at Kolonna, several short lived samples from different settlement phases have been 14 C-dated with the AMS method at the VERA laboratory. Bayesian sequencing of the 14 C data according to the stratigraphic position of the samples in the profile was performed to enable estimates of the transition time between the cultural phases. The Aegina Kolonna 14 C sequence is one of the longest existing so far for the Aegean Bronze Age, and therefore of major importance for the absolute Bronze Age chronology in this region. Preliminary results indicate that the Middle Helladic period seems to have started earlier and lasted longer than traditionally assumed. Further, at the present stage of our investigation we can give also a very tentative time frame for the Santorini volcanic eruption which seems to be in agreement with the science derived VDL date.

  1. Geological Identification of Seismic Source at Opak Fault Based on Stratigraphic Sections of the Southern Mountains

    Directory of Open Access Journals (Sweden)

    Hita Pandita

    2016-08-01

    Full Text Available Earthquake is one of the unpredicted natural disasters on our earth. Despite of the absence of high-accuracy method to precisely predict the occurrence of earthquake, numerous studies have been carried out by seismologists to find it. One of the efforts to address the vulnerability of a region to earthquakes is by recognizing the type of rock as the source of the earthquake. Opak Fault is an active fault which was thought to be the source of earthquakes in Yogyakarta and adjacent areas. This study aimed to determine the seismic source types of rocks in Yogyakarta and adjacent areas. The methods were by measuring stratigraphic sections and the layer thickness in the western part of Southern Mountains. Field study was done in 6 (six research sites. Results of stratigraphic measurement indicated the sedimentary rocks in the Southern Mountains was 3.823 km in thick, while the bedrock was more than 1.042 km in thick. Based on the result, the rock types as the seismic source were thought to originate from the continental crust rocks formed of granite and metamorphic complex.

  2. The use of handheld radiometry for the identification of stratigraphic characteristics of Paraiba Basin units

    International Nuclear Information System (INIS)

    Souza, Ebenezer Moreno de; Villar, Heldio Pereira; Lima, Ricardo de Andrade; Lima Filho, Mario

    2000-01-01

    A study on the use of radiometric techniques for the identification of stratigraphic characteristics of Paraiba Basin units was carried out with handheld instrumentation. The area chosen ran from north Pernambuco to south Paraiba. The presence of radioactive material had been previously determined. For this work a portable scintillometer was fixed to the door of a vehicle, on the outside, with the probe directed downwards. Background radiation was measured as 40 cps (counts per second). The scintillometer has an alarm which sounds whenever the measured count rate rises above a pre-established figure, 100 cps in the present case. Monitoring then proceeded manually. In sites where the count rate was much higher than 100 cps, the probe was lowered to the soil surface. Local coordinates were obtained by GPS. Therefore, an isoradioactivity map of the area could be drawn. The comparison between this map and local geological charts showed significant correlation between observed count rates and geologic formations. Low count rates were indicative of the Barreiras formation, whereas the highest rates were obtained for the Gramame formation (with urano-phosphatic lythotypes). It is concluded that handheld radiometry is a useful tool in geological charting, is special in areas where stratigraphic units have been masked by environmental changes and human activities. (author)

  3. USA-USSR protocol

    CERN Multimedia

    1970-01-01

    On 30 November the USA Atomic Energy Commission and the USSR State Committee for the Utilization of Atomic Energy signed, in Washington, a protocol 'on carrying out of joint projects in the field of high energy physics at the accelerators of the National Accelerator Laboratory (Batavia) and the Institute for High Energy Physics (Serpukhov)'. The protocol will be in force for five years and can be extended by mutual agreement.

  4. Applying and improving a sedimentary facies model for exploration of stratigraphic traps in the Austrian Molasse basin

    Energy Technology Data Exchange (ETDEWEB)

    Hinsch, R.; Kofler, N. [Rohoel-Aufsuchungs AG (RAG), Vienna (Austria); Hubbard, S. [Calgary Univ., Calgary (Canada). Dept. of Geology and Geophysics

    2007-09-13

    In the Molasse foreland basin of Upper Austria gas is produced from deep-water sandstones and conglomerates of the Puchkirchen and basal Hall formations (Oligocene-Lower Miocene). The basin is mature, with >750 wells drilled by RAG to date. An extensive 3-D seismic reflection dataset that covers much of the paleo-basin foredeep has been acquired in the study area over the last 15 years. Seismic stratigraphic analysis has revealed that deepwater sedimentation in the basin was dominated by a channel belt up to 5 km wide that transported sediment derived from the Central and Eastern Alps eastward along the basin axis (Linzer, 2001; de Ruig, 2003). Based on these findings, a detailed sedimentary facies model has been developed, outlining several distinct depositional elements that reveal numerous possible stratigraphic trap types (de Ruig and Hubbard, 2006). This depositional model is currently being applied and tested in exploration and refined by ongoing research. Channel abandonment and migration are important processes that resulted in stratigraphic configurations consisting of coarse-grained sandstones and conglomerates overlain by channel and overbank mudstones. This represents ideal reservoir architecture, including porous reservoir facies sealed by impermeable deposits. Additional stratigraphic trapping conditions can result from special spatial arrangements of depositional elements, for example a sandstone-filled tributary channel that is sealed by an overlying mudstone-filled abandonment channel. Recognizing and further improving such stratigraphic trapping configurations are important for future exploration in Upper Austria, where most of the structural traps have been drilled. (orig.)

  5. Late Pliensbachian-early Toarcian paleoenvironmental changes in the Cleveland Basin: new clues from high-resolution trace element analysis

    DEFF Research Database (Denmark)

    Thibault, Nicolas Rudolph; Ruhl, Micha; Ullmann, Clemens Vinzenz

    on the behaviour of elements associated with organic matter and the sulphur cycle such as Ni, Cu, Zn and As. Cu is well-correlated to the TOC whereas As shows an enrichment in the interval of black shale deposition after the CIE and two distinct correlation lines with sulphur, one before and during the event...... Europe after the CIE. Detrital elements (Al, Si, Ti, Zr) are used as proxies for sea-level change and match well previous sequence stratigraphic interpretations in the Cleveland Basin. Black shale deposition and anoxia were favored by a major transgression and appear to be paced by 3rd to 4th order sea...... elements across the late Pliensbachian to middle Toarcian of the Cleveland Basin. The Pl/To boundary CIE is associated with low Total Organic Carbon (TOCZn and Ni, which together suggest that water-mass restriction and anoxia occurred...

  6. Characteristics of Chinese petroleum geology. Geological features and exploration cases of stratigraphic, foreland and deep formation traps

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Chengzao [PetroChina Company Limited, Beijing (China)

    2012-07-01

    The first book of this subject in the recent 10 years. ''Characteristics of Chinese Petroleum Geology: Geological Features and Exploration Cases of Stratigraphic, Foreland and Deep Formation Traps'' systematically presents the progress made in petroleum geology in China and highlights the latest advances and achievements in oil/gas exploration and research, especially in stratigraphic, foreland and deep formation traps. The book is intended for researchers, practitioners and students working in petroleum geology, and is also an authoritative reference work for foreign petroleum exploration experts who want to learn more about this field in China.

  7. Recent developments: USA

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The development of a National Energy Stategy (NES) for the USA is discussed. On July 26, 1989 President Bush directed of the Secretary of Energy to submit to the President a NES based on the following guidelines: to develop a NES through the year 2030 that could be implemented as son as possible, rather than waiting until the next energy crisis; to formulate the program so that it will create public consensus; build upon market reliance, rather than coercion; and to take a can do approach, capitalizing on US scientific knowledge and common abuse

  8. Radioisotope investigations on the stratigraphic distribution of poly/methyl methacrylate/grafted onto leather

    International Nuclear Information System (INIS)

    Pietrucha, K.; Kroh, J.

    1984-01-01

    Investigations on the stratigraphic distribution of poly/methyl methacrylate/ in leather follow our earlier experiments on radiation grafting of vinyl monomers in situ. Polymer distribution was determined for pigskins and cattlehides tanned with basic sulphates of chromium/III/. 14 C-labelled methyl methacrylate was used in present experiments. Precision slicing technique was employed to cut consecutive slices parallel to the grain surface of the radiation modified leather. Quantative analysis of polymer distribution in leather was based on radioactivity measurements. Each layer was burned in Oxymat apparatus and resulting 14 CO 2 was analysed by liquid scintillation method. On the basis of radioactivity measurements and visual observations with light microscope conclusion on desirable distribution of polymer was reached. In the midcorium part of leather polymer is evenly distributed and its content is much higher than for outer layers next to surface and flesh. Mechanism of relevant processes as well as formation and role played by peroxide compounds is discussed

  9. Radioisotope investigations on the stratigraphic distribution of poly(methyl methacrylate) grafted onto leather

    International Nuclear Information System (INIS)

    Pietrucha, K.; Kroh, J.

    1985-01-01

    Investigations on the stratigraphic distribution of poly(methyl methacrylate) in leather follow our earlier experiments on radiation grafting of vinyl monomers in situ. Polymer distribution was determined for pigskins and cattlehides tanned with basic sulphates of chromium (III). 14 C-labelled methyl methacrylate was used in present experiments. Precision slicing technique was employed to cut consecutive slices parallel to the grain surface of the radiation modified leather. Quantitative analysis of polymer distribution in leather was based on radioactivity measurements. Each layer was burned in Oxymat apparatus and resulting 14 CO 2 was analysed by liquid scintillation method. On the basis of radioactivity measurements and visual observations with light microscope conclusion on desirable distribution of polymer was reached. In the midcorium part of leather polymer is evenly distributed and its content is much higher than for outer layers next to surface and flesh. Mechanism of relevant processes as well as formation and role played by peroxide compounds are discussed. (author)

  10. Seismic stratigraphic architecture of the Disko Bay trough-mouth fan system, West Greenland

    Science.gov (United States)

    Hofmann, Julia C.; Knutz, Paul C.

    2015-04-01

    Spatial and temporal changes of the Greenland Ice Sheet on the continental shelf bordering Baffin Bay remain poorly constrained. Then as now, fast-flowing ice streams and outlet glaciers have played a key role for the mass balance and stability of polar ice sheets. Despite their significance for Greenland Ice Sheet dynamics and evolution, our understanding of their long-term behaviour is limited. The central West Greenland margin is characterized by a broad continental shelf where a series of troughs extend from fjords to the shelf margin, acting as focal points for trough-mouth fan (TMF) accummulations. The sea-ward bulging morphology and abrupt shelf-break of these major depositional systems is generated by prograding depocentres that formed during glacial maxima when ice streams reached the shelf edge, delivering large amounts of subglacial sediment onto the continental slope (Ó Cofaigh et al., 2013). The aim of this study is to unravel the seismic stratigraphic architecture and depositional processes of the Disko Bay TMF, aerially the largest single sedimentary system in West Greenland, using 2D and 3D seismic reflection data, seabed bathymetry and stratigraphic information from exploration well Hellefisk-1. The south-west Disko Bay is intersected by a deep, narrow trough, Egedesminde Dyb, which extends towards the southwest and links to the shallower and broader cross-shelf Disko Trough (maximum water depths of > 1000 m and a trough length of c. 370 km). Another trough-like depression (trough length of c. 120 km) in the northern part of the TMF, indicating a previous position of the ice stream, can be distinguished on the seabed topographic map and the seismic images. The Disko Bay TMF itself extends from the shelf edge down to the abyssal plain (abyssal floor depths of 2000 m) of the southern Baffin Bay. Based on seismic stratigraphic configurations relating to reflection terminations, erosive patterns and seismic facies (Mitchum et al., 1977), the TMF

  11. Stratigraphic controls on saltwater intrusion in the Dominguez Gap area of coastal Los Angeles

    Science.gov (United States)

    Edwards, B.D.; Ehman, K.D.; Ponti, D.J.; Reichard, E.G.; Tinsley, J.C.; Rosenbauer, R.J.; Land, M.

    2009-01-01

    The Los Angeles Basin is a densely populated coastal area that significantly depends on groundwater. A part of this groundwater supply is at risk from saltwater intrusion-the impetus for this study. High-resolution seismic-reflection data collected from the Los Angeles-Long Beach Harbor Complex have been combined with borehole geophysical and descriptive geological data from four nearby ??400-m-deep continuously cored wells and with borehole geophysical data from adjacent water and oil wells to characterize the Pliocene to Holocene stratigraphy of the Dominguez Gap coastal aquifer system. The new data are shown as a north-south, two- dimensional, sequence-stratigraphic model that is compared to existing lithostratigraphic models of the Los Angeles Basin in an attempt to better understand pathways of saltwater intrusion into coastal aquifers. Intrusion of saltwater into the coastal aquifer system generally is attributed to over-pumping that caused the hydraulic gradient to reverse during the mid-1920s. Local water managers have used the existing lithostratigraphic model to site closely spaced injection wells of freshwater (barrier projects) attempting to hydraulically control the saltwater intrusion. Improved understanding of the stratigraphic relationships can guide modifications to barrier design that will allow more efficient operation. Allostratigraphic nomenclature is used to define a new sequence-stratigraphic model for the area because the existing lithostratigraphic correlations that have been used to define aquifer systems are shown not to be time-correlative. The youngest sequence, the Holocene Dominguez sequence, contains the Gaspur aquifer at its base. The Gaspur aquifer is intruded with saltwater and consists of essentially flat-lying gravelly sands deposited by the ancestral Los Angeles River as broad channels that occupied a paleovalley incised into the coastal plain during the last glacio-eustatic highstand. The underlying sequences are deformed into

  12. Structural, stratigraphic and hydrodynamic analysis of the Paleozoic section of central New York State

    International Nuclear Information System (INIS)

    Willette, P.D.

    1979-01-01

    A structural, stratigraphic and hydrodynamic analysis of 12 formations in central New York State between longitudes 75 30' and 78 30' is presented in the form of structure, isopach and potentiometric-fluid flow maps. Information used in the study was obtained from 2804 wells drilled for gas and oil. New concepts, approaches or reinterpretations of ideas presented in previous studies include: evidence of Taconic orogenic features as far west as Rochester, structural control of Trenton gas fields, a new interpretation of Oriskany erosional features and Onondaga reef trends, and structurally controlled fluid-flow patterns. Because fluid flow is toward the water supply of major population centers and because of the likelihood of drilling for natural gas in the area, the Salina Formation in central New York State is not a good site for a high level radioactive waste repository

  13. Oyster-bioimmured ammonites from the Upper Albian of Annopol, Poland: stratigraphic and palaeobiogeographic implications

    Science.gov (United States)

    Machalski, Marcin; Kennedy, William J.

    2013-12-01

    Machalski, M. and Kennedy, W.J. 2013. Oyster-bioimmured ammonites from the Upper Albian of Annopol, Poland: stratigraphic and palaeobiogeographic implications. Acta Geologica Polonica, 63 (4), 545-554. Warszawa. Ammonites Mortoniceras (Subschloenbachia) sp. are preserved as attachment scars on the oyster shells from the topmost portion of the Albian succession at Annopol, Poland. These oyster-bioimmured ammonites show a closest affinity to the representatives of Mortoniceras (Subschloenbachia) characteristic of the upper Upper Albian Mortoniceras perinflatum Zone. No ammonites indicative of the uppermost Albian-lowermost Cenomanian Praeschloenbachia briacensis Zone are recorded. Thus, the hiatus at the Albian-Cenomanian boundary at Annopol embraces the latter zone. The presence (and dominance) of Mortoniceras in the upper Upper Albian ammonite assemblage of Annopol suggests that the representatives of this Tethyan genus could migrate into the epicratonic areas of Poland directly from the Tethyan Realm, via the Lwow (Lviv) region.

  14. A multi-proxy geochemical investigation of late-Quaternary paleoenvironmental change from Burial Lake, Noatak National Preserve, Alaska

    Science.gov (United States)

    Finkenbinder, M. S.; Abbott, M.; Stoner, J. S.; Dorfman, J. M.

    2012-12-01

    Here we present a new multi-proxy geochemical analysis of paleoenvironmental change inferred from sediment cores recovered from Burial Lake (68.434° N, 159.174° W; 430 m ASL) in northwest Alaska. Previous work on cores from 7.9 m water depth sampled at comparatively low resolution revealed basal sediments date to ~ 40,000 cal yr BP and an unconformity during a period of aridity around the Last Glacial Maximum (LGM). We therefore collected multiple overlapping Livingston cores from the lake depocenter (21.5 m water depth) in the summer of 2010 in an effort to develop a temporally continuous, high resolution record spanning prior to the LGM to the present. We focus our interpretations on a 6.51 m core developed through wiggle matching proxy data from core sites A10 and C10. We use traditional laboratory methods and investigate new approaches to assess changes in sedimentation and productivity. We are measuring dry bulk density, organic matter via Loss-on-ignition at 550° C, biogenic silica, magnetic susceptibility, grain size via laser diffractometry, and elemental abundances via scanning x-ray fluorescence (XRF). Future research seeks to test the reliability of two commonly used XRF proxies, for organic matter (incoherence/coherence ratios) and aquatic productivity (Si/Ti ratios). Age control is provided by 12 Accelerator Mass Spectrometry radiocarbon dates of discrete terrestrial macrofossils. Results from these analyses indicate that the depocenter core is continuous and the sediment record spans the last ~ 38,000 cal yr BP and most importantly contains sediments spanning the LGM. Preliminary geochemical results demonstrate substantial cyclicity in organic matter and aquatic productivity beginning in the late-glacial. We seek to analyze the periodicity of these proxies through spectral analysis, although initial observations suggest multi-century to millennial scale variability. In addition, we note the presence of two abrupt, non-linear transitions in organic

  15. Radial ooids from Great Salt Lake (Utah) as paleoenvironmental archives: Insights from radiocarbon chronology and stable isotopes

    Science.gov (United States)

    Paradis, O. P.; Corsetti, F. A.; Bardsley, A.; Hammond, D. E.; Xu, X.; Walker, J. C.

    2017-12-01

    in a relative sense, with evidence for a higher lake altitude around 2700 yr BP. We conclude that 1) 14C-dating using sequential leaching methods indicates ooids began forming in Great Salt Lake over 6,000 yr BP and have continued to the present; and 2) lacustrine ooids are robust high-resolution paleoenvironmental archives when paired with radiochronology.

  16. Sedimentological and Stratigraphic Controls on Natural Fracture Distribution in Wajid Group, SW Saudi Arabia

    Science.gov (United States)

    Benaafi, Mohammed; Hariri, Mustafa; Abdullatif, Osman; Makkawi, Mohammed; Korvin, Gabor

    2016-04-01

    The Cambro-Permian Wajid Group, SW Saudi Arabia, is the main groundwater aquifer in Wadi Al-Dawasir and Najran areas. In addition, it has a reservoir potentiality for oil and natural gas in Rub' Al-Khali Basin. Wajid Group divided into four formations, ascending Dibsiyah, Sanamah, Khussyayan and Juwayl. They are mainly sandstone and exposed in an area extend from Wadi Al-Dawasir southward to Najran city and deposited within fluvial, shallow marine and glacial environments. This study aims to investigate the sedimentological and stratigraphic controls on the distribution of natural fractures within Wajid Group outcrops. A scanline sampling method was used to study the natural fracture network within Wajid Group outcrops, where the natural fractures were measured and characterized in 12 locations. Four regional natural fracture sets were observed with mean strikes of 050o, 075o, 345o, and 320o. Seven lithofacies characterized the Wajid Group at these locations and include fine-grained sandstone, coarse to pebbly sandstone, cross-bedded sandstone, massive sandstone, bioturbated sandstone, conglomerate sandstone, and conglomerate lithofacies. We found that the fine-grained and small scale cross-bedded sandstones lithofacies are characterized by high fracture intensity. In contrast, the coarse-grained sandstone and conglomerate lithofacies have low fracture intensity. Therefore, the relative fracture intensity and spacing of natural fractures within Wajid Group in the subsurface can be predicted by using the lithofacies and their depositional environments. In terms of stratigraphy, we found that the bed thickness and the stratigraphic architecture are the main controls on fractures intensity. The outcomes of this study can help to understand and predict the natural fracture distribution within the subsurface fractured sandstone hosting groundwater and hydrocarbon in Wajid and Rub' Al-Khali Basins. Hence, the finding of this study might help to explore and develop the

  17. Neoproterozoic stratigraphic framework of the Tarim Craton in NW China: Implications for rift evolution

    Science.gov (United States)

    Wu, Lin; Guan, Shuwei; Zhang, Shuichang; Yang, Haijun; Jin, Jiuqiang; Zhang, Xiaodan; Zhang, Chunyu

    2018-06-01

    The Tarim Craton is overlain by thick Neoproterozoic sedimentary successions in rift tectonic setting. This study examines the latest outcrop, seismic, and drilling core data with the objective of investigating the regional stratigraphy to deeply recognize the evolution of rifting in the craton. Cryogenian to Lower Ediacaran successions are mainly composed of clastic rocks with thicknesses of 2000-3000 m, and the Upper Ediacaran successions are composed of carbonate rocks with thicknesses of 500-800 m. The rift basins and stratigraphic zones are divided into northern and southern parts by a central paleo-uplift. The northern rift basin extends through the northern Tarim Craton in an E-W direction with two depocenters (Aksu and Kuruktag). The southern rift basin is oriented NE-SW. There are three or four phases of tillites in the northern zone, while there are two in the southern zone. Given the north-south difference of the stratigraphic framework, the northern rift basin initiated at ca. 740 Ma and the southern rift basin initiated at ca. 780 Ma. During the Cryogenian and Ediacaran, the northern and southern rift basins were separated by the central paleo-uplift, finally connecting with each other in the early Cambrian. Tectonic deformation in the Late Ediacaran led to the formation of a parallel unconformity in the rift basins and an angular unconformity in the central paleo-uplift. The Neoproterozoic rift basins continued to affect the distribution of Lower Cambrian hydrocarbon source rocks. The north-south distribution and evolution of the rift basins in the Tarim Craton have implications for reconstructions of the Rodinia supercontinent.

  18. Controlling factors of stratigraphic occurrences of fine-grained turbidites: Examples from the Japanese waters

    Science.gov (United States)

    Ikehara, K.

    2017-12-01

    Fine-grained turbidite has been used for subaqueous paleoseismology, and has been recognized from shallow- to deep-water environments around the Japanese islands. Stratigraphic occurrence of fine-grained turbidites in the deepest Beppu Bay, south Japan, with its water depth of 75 m suggest clear influence of sea-level changes. Turbidite frequency was high during the post glacial sea-level rising and last 2.7 ka, and was low during the Holocene maximum sea-level highstand (5.3-2.7 ka). Retreat and progress of coastal delta front of the nearby river might affect the sediment supply to the deepest basin. On the other hand, fine-grained turbidites found in the forearc basins ( 3500 and 4500 m in water depths) and trench floor ( 6000 m in water depth) along the southern Ryukyu arc have no clear relation with sea-level changes. Sediment and bathymetric characteristics suggest that origin of these fine-grained turbidites is Taiwan. Remarkable tectonic uplift of Taiwanese coast with small mountainous rivers and narrow shelf may produce the continuous supply of fine-grained turbidites in this area. The Japan Trench floor composes of a series of small basins reflecting subducting horst-graben structure of the Pacific Plate. Each small basin acts as a natural sediment trap receiving the earthquake-induced turbidity currents. Thick fine-grained turbidites are also occurred in the small basins in the Japan Trench floor ( 7500 m in water depth). These are most likely induced by huge earthquakes along the Japan Trench. Thus, their stratigraphic occurrences might have close relation with recurrence of huge earthquakes in the past.

  19. The necessity and application of stratigraphic borings in hydrogeologic site assessments

    International Nuclear Information System (INIS)

    Sciacca, J.

    1991-01-01

    The siting and placement of monitoring wells is one of the most critical elements in hydrogeologic assessments of contaminated sites. Monitoring wells are placed to collect hydraulic and chemical concentration data to: (1) determine potential groundwater flow paths and rates: (2) analyze the nature and extent of chemical constituents in groundwater; and (3) estimate contaminant fate and transport. In many instances monitoring wells provide inappropriate or erroneous hydraulic data, do not provide coverage of potential high permeability flow pathways (such as channel sands) or may themselves create (through improper construction) a vertical conduit for contaminant flow from low permeability to high permeability units. This problem is commonly due to installing monitoring wells before conducting essential stratigraphic analysis and formulating a depositional model for the site area. This paper presents case examples where stratigraphic borings were drilled and logged in the vicinity of proposed well locations to effectively design and install the monitoring well network. The borings were continuously sampled or geophysically logged to provide a vertical profile of the borehole. In addition, the geophysical logs provided curve signatures which allowed interpretation of depositional facies. These data were used to interpret subsurface stratigraphy and effectively position monitoring wells that achieve the above objectives and prevent problems associated with faulty well positioning. This method may cost more initially. However, these initial costs are cheaper than long-term project expenses for abandoning improperly completed wells. subsequently installing supplemental monitoring wells or modifying poorly designed treatment systems which resulted from improper or insufficient data generated from the initial monitoring network

  20. Stratigraphical sequence and geochronology of the volcanic rock series in caifang basin, south jiangxi

    International Nuclear Information System (INIS)

    Xu Xunsheng; Wu Jianhua

    2010-01-01

    The late Mesozoic volcanic rocks in Jiangxi constitute two volcanic belts: the northern is Xiajiang-Guangfeng volcanic belt, the volcanic rocks series belong to one volcano cycle and named Wuyi group which is subdivided into three formations (Shuangfengling formation, Ehuling formation and Shixi formation); the southern is Sannan-Xunwu volcanic belt, the volcanic rocks series in Caifang basin which locates on Sannan-Xunwu volcanic belt also belong to only one volcano cycle. It can be subdivided into two lithology and lithofacies units (upper and lower): the lower unit consists of sedimentary rocks and associated with a subordinate amount of volcanic rocks, it belongs to erupt-deposit facies which is the product of early volcanic stage; the upper unit is mostly composed of volcanic rocks, it belongs to erupt facies that is the volcanic eruption product. SHRIMP zircon U-Pb age of rhyolite? which locates at the top of the upper unit is 130.79 ± 0.73) Ma. According to the new International Stratigraphic Chart, the boundary of Jurassic and Cretaceous is (145.4 ± 4.0) Ma, so the age shows that the geologic period of Caifang volcanic rocks series is early Early Cretaceous epoch. On the basis of lithological correlation, lithofacies and stratigraphic horizon analysis, the volcanic rock series in Caifang basin fall under Wuyi group, and the lower unit could be incorporated into Shuangfengling formation, the upper unit could be incorporated into Ehuling formation. The subdivision of sequence and the determination of geochronology of the volcanic rock series in Caifang basin provide some references for the study of the late Mesozoic volcanic rocks series of the Sannan-Xunwu volcanic belt. (authors)

  1. Stratigraphic controls on fluid and solute fluxes across the sediment-water interface of an estuary

    Science.gov (United States)

    Sawyer, Audrey H.; Lazareva, Olesya; Kroeger, Kevin D.; Crespo, Kyle; Chan, Clara S.; Stieglitz, Thomas; Michael, Holly A.

    2014-01-01

    Shallow stratigraphic features, such as infilled paleovalleys, modify fresh groundwater discharge to coastal waters and fluxes of saltwater and nutrients across the sediment–water interface. We quantify the spatial distribution of shallow surface water–groundwater exchange and nitrogen fluxes near a paleovalley in Indian River Bay, Delaware, using a hand resistivity probe, conventional seepage meters, and pore-water samples. In the interfluve (region outside the paleovalley) most nitrate-rich fresh groundwater discharges rapidly near the coast with little mixing of saline pore water, and nitrogen transport is largely conservative. In the peat-filled paleovalley, fresh groundwater discharge is negligible, and saltwater exchange is deep (∼1 m). Long pore-water residence times and abundant sulfate and organic matter promote sulfate reduction and ammonium production in shallow sediment. Reducing, iron-rich fresh groundwater beneath paleovalley peat discharges diffusely around paleovalley margins offshore. In this zone of diffuse fresh groundwater discharge, saltwater exchange and dispersion are enhanced, ammonium is produced in shallow sediments, and fluxes of ammonium to surface water are large. By modifying patterns of groundwater discharge and the nature of saltwater exchange in shallow sediments, paleovalleys and other stratigraphic features influence the geochemistry of discharging groundwater. Redox reactions near the sediment–water interface affect rates and patterns of geochemical fluxes to coastal surface waters. For example, at this site, more than 99% of the groundwater-borne nitrate flux to the Delaware Inland Bays occurs within the interfluve portion of the coastline, and more than 50% of the ammonium flux occurs at the paleovalley margin.

  2. Tšarterkool USA-s / Johannes Kiersch

    Index Scriptorium Estoniae

    Kiersch, Johannes

    2001-01-01

    24.-27. mainì 01 toimub Tallinnas EFFE 2001 (European Forum of Freedom in Education) konverents "Haridus tänases kodanikuühiskonnas." Konverentsil esineb ka Witteni Waldorf-pedagoogika Instituudi õppejõud Johannes Kiersch. Lähemalt tema artiklist USA-s populaarsust võitvate tsharterkoolide kohta, mis on riigi- ja erakooli vahevorm

  3. Petroleum system elements within the Late Cretaceous and Early Paleogene sediments of Nigeria's inland basins: An integrated sequence stratigraphic approach

    Science.gov (United States)

    Dim, Chidozie Izuchukwu Princeton; Onuoha, K. Mosto; Okeugo, Chukwudike Gabriel; Ozumba, Bertram Maduka

    2017-06-01

    Sequence stratigraphic studies have been carried out using subsurface well and 2D seismic data in the Late Cretaceous and Early Paleogene sediments of Anambra and proximal onshore section of Niger Delta Basin in the Southeastern Nigeria. The aim was to establish the stratigraphic framework for better understanding of the reservoir, source and seal rock presence and distribution in the basin. Thirteen stratigraphic bounding surfaces (consisting of six maximum flooding surfaces - MFSs and seven sequence boundaries - SBs) were recognized and calibrated using a newly modified chronostratigraphic chart. Stratigraphic surfaces were matched with corresponding foraminiferal and palynological biozones, aiding correlation across wells in this study. Well log sequence stratigraphic correlation reveals that stratal packages within the basin are segmented into six depositional sequences occurring from Late Cretaceous to Early Paleogene age. Generated gross depositional environment maps at various MFSs show that sediment packages deposited within shelfal to deep marine settings, reflect continuous rise and fall of sea levels within a regressive cycle. Each of these sequences consist of three system tracts (lowstand system tract - LST, transgressive system tract - TST and highstand system tract - HST) that are associated with mainly progradational and retrogradational sediment stacking patterns. Well correlation reveals that the sand and shale units of the LSTs, HSTs and TSTs, that constitute the reservoir and source/seal packages respectively are laterally continuous and thicken basinwards, due to structural influences. Result from interpretation of seismic section reveals the presence of hanging wall, footwall, horst block and collapsed crest structures. These structural features generally aid migration and offer entrapment mechanism for hydrocarbon accumulation. The combination of these reservoirs, sources, seals and trap elements form a good petroleum system that is viable

  4. UPPER PLEISTOCENE SMALL MAMMAL FAUNA FROM SALNOVA QUARRY (SALTRIO-VARESE-NORTHWESTERN LOMBARDY: PALEOENVIRONMENTAL RECONSTRUCTION AND CHIONOMYS NIVALIS POPULATION STUDY

    Directory of Open Access Journals (Sweden)

    FABIO BONA

    2011-07-01

    Full Text Available The small mammals collection described in the present paper has been collected during three field small excavation at the Upper Pleistocene site of Cava Salnova (Saltrio - VA -. The collection consists of 501 determined remains of small mammals coming from all 17 stratigraphical levels and belonging at least to 26 species. Two 14C datings (AMS has been made on small mammals bones belonging to the lev. 1b: 1- 34315 ± 200 yr BP; 2- 35101± 250 yr BP. The interpretation of faunal data enables us to propose the following palaeoenvironmental framework: lower levels, lev. b and liv. c, are characterized by a cool weather with a high degree of plant cover. The deposition of lev. e to the lev. g coincided with an important reforestation occurred at the same time of the hottest Wurmian interpleniglacial. In lev. m, n, o, the snow vole, although rare, reappears. This may indicate the beginning of the climatic cooling, which is the prelude to the Last Glacial Maximum. 

  5. Paleoenvironmental change as derived from loess sediment properties: Examples of last glacial loess sites from the Carpathian Basin

    Science.gov (United States)

    Lehmkuhl, Frank; Zeeden, Christian; Bösken, Janina; Eckmeier, Eileen; Hambach, Ulrich; Hauck, Thomas; Klasen, Nicole; Markovic, Slobodan; Obreht, Igor; Schulte, Philipp; Sümegi, Pal; Chu, Wei; Timar-Gabor, Alida; Veres, Daniel

    2015-04-01

    The project B1 within the CRC 806 "Our way to Europe" focuses on the "Eastern Trajectory" of modern human migration from Africa into Europe. The Middle East, and SE Europe constitute the principal areas to be investigated. SE Europe has become a special research focus since two early Homo sapiens individuals have been found at Oase Cave in the southern Banat. The fossils lack any stratigraphic context; cultural and environmental circumstances of these findings have remained unclear. In the neighbourhood of Oase Cave, however, several early Upper Palaeolithic sites, embedded in loess sequences were known since the 1950's. Some sites were re-investigated by our research team. Conceptionally we are following the idea of upland-lowland interaction, which combines parameters as sedimentary transport, sediment distribution, and paleosol development in different altitudes, all influenced by paleoclimate in space and time. Furthermore, some detailed studies concerning site-formation processes and the quality of open-air sites (sedimentary development, paleoecology, multilayering, reworking, human impact on soils and sediments) are being conducted at selected localities. Recent investigations of the loess-paleosol sequences (LPS) in SE Europe provided important environmental information which differ from "classical" ecological approaches derived from other European loess provinces. New luminescence dating results provide a sensitive chronology of environmental changes recorded in the LPS from both upland and lowland positions, giving the potential to link these.

  6. TTÜ ja TÜ osalevad USA armee miljoniprojektides

    Index Scriptorium Estoniae

    2016-01-01

    TTÜ ja TÜ liitusid USA-s tegutseva meditsiinitehnoloogia ettevõtete konsortsiumiga. Nii jõuavad juhtivate Eesti kõrgkoolide teadmised USA armeesse, kes konsortsiumi kaudu innovaatilisi tooteid ja teenuseid sisse ostab

  7. Heritability of the Structures and 13C Fractionation in Tomato Leaf Wax Alkanes: A Genetic Model System to Inform Paleoenvironmental Reconstructions

    Directory of Open Access Journals (Sweden)

    Amanda L. D. Bender

    2017-06-01

    Full Text Available Leaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of n-alkanes as a paleoenvironmental proxy may be modulated by the extent to which biological as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is usually an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2H of waxes via rainwater and the δ13C of leaf waxes by changing plant communities. We measured the degree of genetic control over δ13C variation in leaf waxes within closely related species with an experimental greenhouse growth study. We measured the proportion of variability in structural and isotopic leaf wax traits that is attributable to genetic variation using a set of 76 introgression lines (ILs between two interfertile Solanum (tomato species: S. lycopersicum cv M82 (hereafter cv M82 and S. pennellii. Leaves of S. pennellii, a wild desert tomato relative, produced significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions. We report a methylation index to summarize the ratio of branched (iso- and anteiso- to total alkanes. Between Solanum pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2–1.4‰ over n-alkanes. The broad-sense heritability values (H2 of leaf wax traits describe the degree to which genetic variation contributes to variation of these traits. Variation of individual carbon isotopic compositions of alkanes were of low heritability (H2 = 0.13–0.19, suggesting that most variation in δ13C of leaf waxes in this study can be attributed to environmental variance. This supports the interpretation that variation in the δ13C of wax compounds recorded in sediments

  8. Heritability of the structures and 13C fractionation in tomato leaf wax alkanes: a genetic model system to inform paleoenvironmental reconstructions

    Science.gov (United States)

    Bender, Amanda L. D.; Chitwood, Daniel H.; Bradley, Alexander S.

    2017-06-01

    Leaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of n-alkanes as a paleoenvironmental proxy may be modulated by the extent to which biological as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is usually an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2H of waxes via rainwater and the δ13C of leaf waxes by changing plant communities. We measured the degree of genetic control over δ13C variation in leaf waxes within closely related species with an experimental greenhouse growth study. We measured the proportion of variability in structural and isotopic leaf wax traits that is attributable to genetic variation using a set of 76 introgression lines (ILs) between two interfertile Solanum (tomato) species: S. lycopersicum cv M82 (hereafter cv M82) and S. pennellii. Leaves of S. pennellii, a wild desert tomato relative, produced significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions. We report a methylation index to summarize the ratio of branched (iso- and anteiso-) to total alkanes. Between S. pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2-1.4‰ over n-alkanes. The broad-sense heritability values (H2) of leaf wax traits describe the degree to which genetic variation contributes to variation of these traits. Variation of individual carbon isotopic compositions of alkanes were of low heritability (H2 = 0.13-0.19), suggesting that most variation in δ13C of leaf waxes in this study can be attributed to environmental variance. This supports the interpretation that variation in the δ13C of wax compounds recorded in sediments reflects

  9. Euroopa teadis USA salavanglaist / Tõnis Erilaid

    Index Scriptorium Estoniae

    Erilaid, Tõnis, 1943-

    2005-01-01

    USA endise välisministri Colin Powelli sõnul pole see tema sõpradele Euroopas uudiseks, et USA on viinud vange riikidesse, kus tema seadused ei kehti. USA praeguse välisministri Condoleezza Rice'i sõnul on USA vange üle kuulanud väljaspool USA-d. USA Today kirjeldab Stare Kiejkuty küla Poolas, kus arvatavasti on olnud salavangla

  10. The Brahmaputra River: a stratigraphic analysis of Holocene avulsion and fluvial valley reoccupation history

    Science.gov (United States)

    Hartzog, T. R.; Goodbred, S. L.

    2011-12-01

    The Brahmaputra River, one of the world's largest braided streams, is a major component of commerce, agriculture, and transportation in India and Bangladesh. Hence any significant change in course, morphology, or behavior would be likely to influence the regional culture and economy that relies on this major river system. The history of such changes is recorded in the stratigraphy deposited by the Brahmaputra River during the Holocene. Here we present stratigraphic analysis of sediment samples from the boring of 41 tube wells over a 120 km transect in the upper Bengal Basin of northern Bangladesh. The transect crosses both the modern fluvial valley and an abandoned fluvial valley about 60 km downstream of a major avulsion node. Although the modern Brahmaputra does not transport gravel, gravel strata are common below 20 m with fluvial sand deposits dominating most of the stratigraphy. Furthermore, the stratigraphy preserves very few floodplain mud strata below the modern floodplain mud cap. These preliminary findings will be assessed to determine their importance in defining past channel migration, avulsion frequency, and the reoccupation of abandoned fluvial valleys. Understanding the avulsion and valley reoccupation history of the Brahmaputra River is important to assess the risk involved with developing agriculture, business, and infrastructure on the banks of modern and abandoned channels. Based on the correlation of stratigraphy and digital surface elevation data, we hypothesize that the towns of Jamalpur and Sherpur in northern Bangladesh were once major ports on the Brahmaputra River even though they now lie on the banks of small underfit stream channels. If Jamalpur and Sherpur represent the outer extent of the Brahmaputra River braid-belt before the last major avulsion, these cities and any communities developed in the abandoned braid-belt assume a high risk of devastation if the next major avulsion reoccupies this fluvial valley. It is important to

  11. Salt tectonics and sequence-stratigraphic history of minibasins near the Sigsbee Escarpment, Gulf of Mexico

    Science.gov (United States)

    Montoya, Patricia

    The focus of this research is to understand the stratigraphic and structural evolution of lower-slope minibasins in the Gulf of Mexico by examining the influence of salt tectonics on sediment transport systems and deep-water facies architecture. Results showed that gravitational subsidence and shortening can cause variations in the relief of salt massifs on opposing sides of a minibasin. These bathymetric variations, combined with changes in sedimentation rates through time, affected not only the distribution of deep-water facies inside the minibasins, but also influenced the evolution of sediment transport systems between minibasins. In order to understand the evolution of salt massifs, this dissertation presents a new approach to evaluate qualitatively the rate of relative massif uplift based on depoaxis shifts and channel geometries identified in minibasins surrounded by mobile salt. From these results it was established that compression was long-lived, and that extension only dominated during late intervals. Stratigraphic analyses showed that there is a strong cyclicity in deep-water facies stacking patterns within lower-slope minibasins, related primarily to cyclical changes in sedimentation rates. A typical sequence starts with a period of slow sedimentation associated with drape facies above each sequence boundary. Then, towards the middle and final stages of the sequence, sedimentation rates increase and turbidity flows fill the minibasin. Previous studies describe processes of fill-and-spill for two adjacent minibasins in the upper and middle slope. However, these models fail to adequately explain fill-and-spill processes in lower slope minibasins surrounded by mobile salt. In particular, they do not consider the effect of variations in bathymetric relief of the intervening massif, nor do they examine multidirectional connections between proximal and distal minibasins. A new dynamic-salt fill-and-spill model is proposed in this dissertation in order to

  12. Sequence stratigraphic interpretation of parts of Anambra Basin, Nigeria using geophysical well logs and biostratigraphic data

    Science.gov (United States)

    Anakwuba, E. K.; Ajaegwu, N. E.; Ejeke, C. F.; Onyekwelu, C. U.; Chinwuko, A. I.

    2018-03-01

    The Anambra basin constitutes the southeastern lower portion of the Benue Trough, which is a large structural depression that is divided into lower, middle and upper parts; and is one of the least studied inland sedimentary basins in Nigeria. Sequence stratigraphic interpretation had been carried out in parts of the Anambra Basin using data from three wells (Alo-1 Igbariam-1 and Ajire-1). Geophysical well logs and biostratigraphic data were integrated in order to identify key bounding surfaces, subdivide the sediment packages, correlate sand continuity and interpret the environment of deposition in the fields. Biostratigraphic interpretation, using foraminifera and plankton population and diversity, reveals five maximum flooding surfaces (MFS) in the fields. Five sequence boundaries (SB) were also identified using the well log analysis. Four 3rd order genetic sequences bounded by maximum flooding surfaces (MFS-1 to MFS-6) were identified in the areas; four complete sequences and one incomplete sequence were identified in both Alo-1 and Igbariam-1 wells while Ajire-1 has an no complete sequence. The identified system tracts delineated comprises Lowstand Systems Tracts (progradational to aggradational to retrogradational packages), Transgressive Systems Tracts (retrogradational packages) and Highstand Systems Tracts (aggradational to progradational packages) in each well. The sand continuity across the fields reveal sands S1 to S5 where S1 is present in Ajire-1 well and Igbariam-1 well but not in Alo-1 well. The sands S4 to S5 run across the three fields at different depths. The formations penetrated by the wells starting from the base are; Nkporo Formation (Campanian), Mamu Formation (Late Campanian to Early Maastrichtian), Ajali Sandstone (Maastrichtian), Nsukka Formation (Late Maastrichtian to Early Palaeocene), Imo Formation (Palaeocene) and Nanka Sand (Eocene). The environments of deposition revealed are from coastal to bathyal. The sands of lowstand system

  13. Paleomagnetic constrains in the reconstruction of the recent stratigraphic evolution of the Po delta

    Science.gov (United States)

    Correggiari, Annamaria; Vigliotti, Luigi; Remia, Alessandro; Perini, Luisa; Calabrese, Lorenzo; Luciani, Paolo

    2014-05-01

    The delta and prodelta deposits are characterized by a complex stratigraphic architecture that can be approached with several multidisciplinary tools. We present an example from the Po delta system characterized by alternating phases of rapid advance and abandonment of its multiple deltaic lobes that has been investigated through: (1) a review of historical cartography extending back several centuries; (2) integrated surveys of VHR seismic profiles recorded offshore of the modern delta from water depths as shallow as 5 m to the toe of the prodelta in about 30 m; and (3) sedimentological and geochronological data from precisely positioned sediment cores. Within this well known stratigraphic framework we have acquired seismic data and sediment cores in the area of the post roman Po delta system. However a precise dating of the recent evolution of depositional delta lobes is difficult because of the lack of suitable dating methods. To constrain the emplacement timing of the Renaissance lobes a paleomagnetic studies was carried out on a sedimentary sequence representing a seismic facies well correlated in the cores by whole core magnetic susceptibility profile. Forty eight samples were collected from a core section (RER96-1) characterized by a fine grained lithology suitable for paleomagnetic investigations. The characteristic remanent magnetization (ChRM) of the sediments has been obtained by applying an AF cleaning between 10 and 30 millitesla. The results have been compared with the directions recorded by the historical lavas of the Etna and Vesuvius. The combination of the trends observed in the declination and inclination suggests that the results can be compatible with the directions of the secular variation of the earth magnetic field occurring during the XVII century. This allow to date the sismic unit as representative of the beginning of the new delta following the Porto Viro avulsion made by the Venice Republic in 1604 AD. This delta history reflects the

  14. Variations in petrophysical properties of shales along a stratigraphic section in the Whitby mudstone (UK)

    Science.gov (United States)

    Barnhoorn, Auke; Houben, Maartje; Lie-A-Fat, Joella; Ravestein, Thomas; Drury, Martyn

    2015-04-01

    In unconventional tough gas reservoirs (e.g. tight sandstones or shales) the presence of fractures, either naturally formed or hydraulically induced, is almost always a prerequisite for hydrocarbon productivity to be economically viable. One of the formations classified so far as a potential interesting formation for shale gas exploration in the Netherlands is the Lower Jurassic Posidonia Shale Formation (PSF). However data of the Posidonia Shale Formation is scarce so far and samples are hard to come by, especially on the variability and heterogeneity of the petrophysical parameters of this shale little is known. Therefore research and sample collection is conducted on a time and depositional analogue of the PSF: the Whitby Mudstone Formation (WMF) in the United Kingdom. A large number of samples along a ~7m stratigraphic section of the Whitby Mudstone Formation have been collected and analysed. Standard petrophysical properties such as porosity and matrix densities are quantified for a number of samples throughout the section, as well as mineral composition analysis based on XRD/XRF and SEM analyses. Seismic velocity measurements are also conducted at multiple heights in the section and in multiple directions to elaborate on anisotropy of the material. Attenuation anisotropy is incorporated as well as Thomsen's parameters combined with elastic parameters, e.g. Young's modulus and Poisson's ratio, to quantify the elastic anisotropy. Furthermore rock mechanical experiments are conducted to determine the elastic constants, rock strength, fracture characteristics, brittleness index, fraccability and rock mechanical anisotropy across the stratigraphic section of the Whitby mudstone formation. Results show that the WMF is highly anisotropic and it exhibits an anisotropy on the large limit of anisotropy reported for US gas shales. The high anisotropy of the Whitby shales has an even larger control on the formation of the fracture network. Furthermore, most petrophysical

  15. Stratigraphic architecture of bedrock reference section, Victoria Crater, Meridiani Planum, Mars

    Science.gov (United States)

    Edgar, Lauren A.; Grotzinger, John P.; Hayes, Alex G.; Rubin, David M.; Squyres, Steve W.; Bell, James F.; Herkenhoff, Ken E.

    2012-01-01

    The Mars Exploration Rover Opportunity has investigated bedrock outcrops exposed in several craters at Meridiani Planum, Mars, in an effort to better understand the role of surface processes in its geologic history. Opportunity has recently completed its observations of Victoria crater, which is 750 m in diameter and exposes cliffs up to ~15 m high. The plains surrounding Victoria crater are ~10 m higher in elevation than those surrounding the previously explored Endurance crater, indicating that the Victoria crater exposes a stratigraphically higher section than does the Endurance crater; however, Victoria strata overlap in elevation with the rocks exposed at the Erebus crater. Victoria crater has a well-developed geomorphic pattern of promontories and embayments that define the crater wall and that reveal thick bedsets (3–7m) of large-scale cross-bedding, interpreted as fossil eolian dunes. Opportunity was able to drive into the crater at Duck Bay, located on the western margin of Victoria crater. Data from the Microscopic Imager and Panoramic Camera reveal details about the structures, textures, and depositional and diagenetic events that influenced the Victoria bedrock. A lithostratigraphic subdivision of bedrock units was enabled by the presence of a light-toned band that lines much of the upper rim of the crater. In ascending order, three stratigraphic units are named Lyell, Smith, and Steno; Smith is the light-toned band. In the Reference Section exposed along the ingress path at Duck Bay, Smith is interpreted to represent a zone of diagenetic recrystallization; however, its upper contact also coincides with a primary erosional surface. Elsewhere in the crater the diagenetic band crosscuts the physical stratigraphy. Correlation with strata present at nearby promontory Cape Verde indicates that there is an erosional surface at the base of the cliff face that corresponds to the erosional contact below Steno. The erosional contact at the base of Cape Verde

  16. Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Overview of scientific and technical program

    Science.gov (United States)

    Hunter, R.B.; Collett, T.S.; Boswell, R.; Anderson, B.J.; Digert, S.A.; Pospisil, G.; Baker, R.; Weeks, M.

    2011-01-01

    The Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled within the Alaska North Slope (ANS) Milne Point Unit (MPU) from February 3 to 19, 2007. The well was conducted as part of a Cooperative Research Agreement (CRA) project co-sponsored since 2001 by BP Exploration (Alaska), Inc. (BPXA) and the U.S. Department of Energy (DOE) in collaboration with the U.S. Geological Survey (USGS) to help determine whether ANS gas hydrate can become a technically and commercially viable gas resource. Early in the effort, regional reservoir characterization and reservoir simulation modeling studies indicated that up to 0.34 trillion cubic meters (tcm; 12 trillion cubic feet, tcf) gas may be technically recoverable from 0.92 tcm (33 tcf) gas-in-place within the Eileen gas hydrate accumulation near industry infrastructure within ANS MPU, Prudhoe Bay Unit (PBU), and Kuparuk River Unit (KRU) areas. To further constrain these estimates and to enable the selection of a test site for further data acquisition, the USGS reprocessed and interpreted MPU 3D seismic data provided by BPXA to delineate 14 prospects containing significant highly-saturated gas hydrate-bearing sand reservoirs. The "Mount Elbert" site was selected to drill a stratigraphic test well to acquire a full suite of wireline log, core, and formation pressure test data. Drilling results and data interpretation confirmed pre-drill predictions and thus increased confidence in both the prospect interpretation methods and in the wider ANS gas hydrate resource estimates. The interpreted data from the Mount Elbert well provide insight into and reduce uncertainty of key gas hydrate-bearing reservoir properties, enable further refinement and validation of the numerical simulation of the production potential of both MPU and broader ANS gas hydrate resources, and help determine viability of potential field sites for future extended term production testing. Drilling and data acquisition operations demonstrated that gas hydrate

  17. Future USA development

    International Nuclear Information System (INIS)

    Stephen, J.D.; Biancheria, A.; Leibnitz, D.; O'Reilly, B.D.; Liu, Y.Y.; Labar, M.P.; Gneiting, B.C.

    1979-01-01

    The planning for further development in the USA at this time is a mixture of expectation and guessing. Modeling development is certain to continue, but the target reactor is uncertain. The next plant may or may not use the FFTR driver fuel design. The planning, therefore, emphasizes fundamentals and flexibility. There are many options to be modeled. The FFTF driver fuel performance in FFTF must be evaluated; both the reference and improved designs. A decision to use the FFTR driver design in the large plant will demand predictions on the effects of axial blankets, constant power (rather than decreasing) throughout life, and power changes, behavior beyond breach and design basis transients in large plants. A decision favoring a lower doubling time oxide design adds the effects of higher strength/lower swelling alloys, increased pin diameter, reduced cladding thickness/diameter, increased smeared density, gap versus pellet density, and reduced pin pitch/diameter. A helium bonded carbide design adds concern about increased potential for fuel-cladding-assembly mechanical interactions. And blanket pin performance predictions, either in a homogeneous or a heterogeneous core, add an increasing power history and enhanced assembly interactions. It is possible that the decision will be to choose a first core and retain all options for later cores. The modeling objective, for whatever options are chosen, is to predict the effect of normal and off-normal design conditions on performance limits (i.e., fuel temperature, pin deformation, pin lifetime). Several significant uncertainties in the mechanisms associated with the performance limits remain and will be addressed. These include gap closure, gap conductance and fuel properties at higher burnup, fuel-fission product reactions, retained gas, breach mechanisms, assembly interactions and behavior beyond breach, plus establishing appropriate criteria. The LIFE system, with its elements of 1D and 2D fundamental modeling

  18. Pepeljajev eesti näitlejatega USA-s

    Index Scriptorium Estoniae

    2008-01-01

    Sasha Pepeljajevi tantsulavastust "Uksed" etendati USA rahvusvahelisel teatrifestivalil "Arts & Ideas". Vene-Eesti trupi Apparatus lavastus on pühendatud Daniil Harmsi 100. sünniaastapäevale ning põhineb tema töödel

  19. Stratigraphic and microfossil evidence for a 4500-year history of Cascadia subduction zone earthquakes and tsunamis at Yaquina River estuary, Oregon, USA

    Science.gov (United States)

    Graehl, Nicholas A; Kelsey, Harvey M.; Witter, Robert C.; Hemphill-Haley, Eileen; Engelhart, Simon E.

    2015-01-01

    The Sallys Bend swamp and marsh area on the central Oregon coast onshore of the Cascadia subduction zone contains a sequence of buried coastal wetland soils that extends back ∼4500 yr B.P. The upper 10 of the 12 soils are represented in multiple cores. Each soil is abruptly overlain by a sandy deposit and then, in most cases, by greater than 10 cm of mud. For eight of the 10 buried soils, times of soil burial are constrained through radiocarbon ages on fine, delicate detritus from the top of the buried soil; for two of the buried soils, diatom and foraminifera data constrain paleoenvironment at the time of soil burial.We infer that each buried soil represents a Cascadia subduction zone earthquake because the soils are laterally extensive and abruptly overlain by sandy deposits and mud. Preservation of coseismically buried soils occurred from 4500 yr ago until ∼500–600 yr ago, after which preservation was compromised by cessation of gradual relative sea-level rise, which in turn precluded drowning of marsh soils during instances of coseismic subsidence. Based on grain-size and microfossil data, sandy deposits overlying buried soils accumulated immediately after a subduction zone earthquake, during tsunami incursion into Sallys Bend. The possibility that the sandy deposits were sourced directly from landslides triggered upstream in the Yaquina River basin by seismic shaking was discounted based on sedimentologic, microfossil, and depositional site characteristics of the sandy deposits, which were inconsistent with a fluvial origin. Biostratigraphic analyses of sediment above two buried soils—in the case of two earthquakes, one occurring shortly after 1541–1708 cal. yr B.P. and the other occurring shortly after 3227–3444 cal. yr B.P.—provide estimates that coseismic subsidence was a minimum of 0.4 m. The average recurrence interval of subduction zone earthquakes is 420–580 yr, based on an ∼3750–4050-yr-long record and seven to nine interearthquake intervals.The comparison of the Yaquina Bay earthquake record to similar records at other Cascadia coastal sites helps to define potential patterns of rupture for different earthquakes, although inherent uncertainty in dating precludes definitive statements about rupture length during earthquakes. We infer that in the first half of the last millennia, the northern Oregon part of the subduction zone had a different rupture history than the southern Oregon part of the subduction zone, and we also infer that at ca. 1.6 ka, two earthquakes closely spaced in time together ruptured a length of the megathrust that extends at least from southwestern Washington to southern Oregon.

  20. Monogenetic origin of Ubehebe Crater maar volcano, Death Valley, California: Paleomagnetic and stratigraphic evidence

    Science.gov (United States)

    Champion, Duane E.; Cyr, Andy; Fierstein, Judy; Hildreth, Wes

    2018-04-01

    Paleomagnetic data for samples collected from outcrops of basaltic spatter at the Ubehebe Crater cluster, Death Valley National Park, California, record a single direction of remanent magnetization indicating that these materials were emplaced during a short duration, monogenetic eruption sequence 2100 years ago. This conclusion is supported by geochemical data encompassing a narrow range of oxide variation, by detailed stratigraphic studies of conformable phreatomagmatic tephra deposits showing no evidence of erosion between layers, by draping of sharp rimmed craters by later tephra falls, and by oxidation of later tephra layers by the remaining heat of earlier spatter. This model is also supported through a reinterpretation and recalculation of the published 10Be age results (Sasnett et al., 2012) from an innovative and bold exposure-age study on very young materials. Their conclusion of multiple and protracted eruptions at Ubehebe Crater cluster is here modified through the understanding that some of their quartz-bearing clasts inherited 10Be from previous exposure on the fan surface (too old), and that other clasts were only exposed at the surface by wind and/or water erosion centuries after their eruption (too young). Ubehebe Crater cluster is a well preserved example of young monogenetic maar type volcanism protected within a National Park, and it represents neither a protracted eruption sequence as previously thought, nor a continuing volcanic hazard near its location.

  1. CORRELATIONS OF THERMAL CONDUCTIVITY BETWEEN STRATIGRAPHIC UNITS IN THE BROADER AREA OF ZAGREB

    Directory of Open Access Journals (Sweden)

    Miron Kovačić

    2007-12-01

    Full Text Available Thermal conductivity (KTV of geological formations is one of the parameters responsible for the propagation of the heat under the earth surface. During geothermal investigations in the broader area of the Croatian capital of Zagreb the thermal conductivity was measured on the rock samples from the surface and the boreholes. The results of the measurements are presented in this work and used as a basis for calculations of the thermal conductivity of distinct geological formations within the investigated area. It was found out that the values of the thermal conductivity of the rocks in the investigated area vary greatly. The measurements are within the well known scope for certain rock types. The thermal conductivity of the rocks from the Tertiary units corresponds with the average values being typical for such kind of rocks, while the basement carbonate rocks are characterized by the values being by 1 W/K-1m-1 higher than the average. After comparing the thermal conductivity of the stratigraphic units in the broader area of Zagreb it has been established that the values of the thermal conductivity of geological formations in the investigated area are also very different, and that they generally rise with their age. The relative relationships show that the Quaternary, Pliocene and Tertiary sedimentary rocks act as thermal insulators, while Triassic rocks behave as the heat conductor (the paper is published in Croatian.

  2. Stratigraphical analysis of the neoproterozoic sedimentary sequences of the Sao Francisco Basin

    International Nuclear Information System (INIS)

    Martins, Mariela; Lemos, Valesca Brasil

    2007-01-01

    A stratigraphic analysis was performed under the principles of Sequence Stratigraphy on the neoproterozoic sedimentary sequences of the Sao Francisco Basin (Central Brazil). Three periods of deposition separated by unconformities were recognized in the Sao Francisco Megasequence: (1) Sequences 1 and 2, a cryogenian glaciogenic sequence, followed by a distal scarp carbonate ramp, developed during stable conditions, (2) Sequence 3, a Upper Cryogenian stack homoclinal ramps with mixed carbonate-siliciclastic sedimentation, deposited under a progressive influence of compressional stresses of the Brasiliano Cycle, (3) Sequence 4, a Lower Ediacaran shallow platform dominated by siliciclastic sedimentation of molassic nature, the erosion product of the nearby uplifted thrust sheets. Each of the carbonate-bearing sequences presents a distinct δ 13 C isotopic signature. The superposition to the global curve for carbon isotopic variation allowed the recognition of a major depositional hiatus between the Paranoa and Sao Francisco Megasequences, and suggested that the glacial diamictite deposition (Jequitai Formation) took place most probably around 800 Ma. This constrains the Sao Francisco Megasequence deposition to the interval between 800 and 600 Ma (the known ages of the Brasiliano Orogeny defines the upper limit). A minor depositional hiatus (700.680 Ma) was also identified separating sequences 2 and 3. Isotopic analyses suggest that from then on, more restricted environmental conditions were established in the basin, probably associated with a first order global event, which prevailed throughout deposition of the Sequence 3. (author)

  3. The geostatistical approach for structural and stratigraphic framework analysis of offshore NW Bonaparte Basin, Australia

    International Nuclear Information System (INIS)

    Wahid, Ali; Salim, Ahmed Mohamed Ahmed; Yusoff, Wan Ismail Wan; Gaafar, Gamal Ragab

    2016-01-01

    Geostatistics or statistical approach is based on the studies of temporal and spatial trend, which depend upon spatial relationships to model known information of variable(s) at unsampled locations. The statistical technique known as kriging was used for petrophycial and facies analysis, which help to assume spatial relationship to model the geological continuity between the known data and the unknown to produce a single best guess of the unknown. Kriging is also known as optimal interpolation technique, which facilitate to generate best linear unbiased estimation of each horizon. The idea is to construct a numerical model of the lithofacies and rock properties that honor available data and further integrate with interpreting seismic sections, techtonostratigraphy chart with sea level curve (short term) and regional tectonics of the study area to find the structural and stratigraphic growth history of the NW Bonaparte Basin. By using kriging technique the models were built which help to estimate different parameters like horizons, facies, and porosities in the study area. The variograms were used to determine for identification of spatial relationship between data which help to find the depositional history of the North West (NW) Bonaparte Basin

  4. The Neo-Alagoas in the Ceara, Araripe and Potiguar basins (Brazil): stratigraphic and paleoecologycal caracterization

    International Nuclear Information System (INIS)

    Hashimoto, A.T.; Appi, C.J.; Soldan, A.L.; Cerqueira, J.R.

    1987-01-01

    The stratigraphic analysis of the Alagoas Stage (local stage) in Ceara Basin allows the investigated interval to be divided into two parts, with distictive tectono-sedimentary and paleobiological features. The lower part shows non-marine environmental character and the upper part, informally named Aptian-Albian transition, contains marine organisms in certain levels. These records would represent the first phases of a primitive equatorial Atlantic Ocean in the area. The Trairi Beds at the top of the continental section were deposited in an environmental complex which includes a marginal sabkha, reflecting cyclical conditions of extreme aridity or humidity. Similar events have ocurred in the Potiguar Basin with the Ponta do Tubarao Beds and in Araripe Basin with the deposition of thinny calcareous and shale layers, here informally named ''Batateria Beds''. These environmental conditions provided an excellent setting for preservation of organic matter due to cyclical anoxic processes. The observation that the organic extracts from shales of all these strata are similar supports the hypothesis of correspondence of these events. (author) [pt

  5. Stratigraphic imaging of sub-basalt sediments using waveform tomography of wide-angle seismic data

    Science.gov (United States)

    Sain, K.; Gao, F.; Pratt, G.; Zelt, C. A.

    2003-12-01

    The oil industry is interested in imaging the fine structures of sedimentary formations masked below basalt flows for commercial exploration of hydrocarbons. Seismic exploration of sediments hidden below high-velocity basalt cover is a difficult problem because near-vertical reflection data are contaminated with multiples, converted waves and scattering noise generated by interbeds, breccia and vesicles within the basalt. The noise becomes less prominent as the source-receiver offset increases, and the signals carrying sub-surface information stand out at the wide-angle range. The tomography of first arrival traveltime data can provide little information about the underlying low-velocity sediments. Traveltime inversion of wide-angle seismic data including both first arrivals and identifiable wide-angle reflected phases has been an important tool in the delineation of the large-scale velocity structure of sub-basalt sediments, although it lacks the small-scale velocity details. Here we apply 2-D full-waveform inversion ("waveform tomography") to wide-angle seismic data with a view to extracting the small-scale stratigraphic features of sedimentary formations. Results from both synthetic data, generated for a realistic earth model, and field dataset from the basalt covered Saurashtra peninsula, India, will be presented. This approach has potential to delineate thin sedimentary layers hidden below thick basalt cover also, and may serve as a powerful tool to image sedimentary basins, where they are covered by high-velocity materials like basalts, salts, carbonates, etc. in various parts of the world.

  6. Stratigraphic response of salt marshes to slow rates of sea-level change

    Science.gov (United States)

    Daly, J.; Bell, T.

    2006-12-01

    Conventional models of salt-marsh development show an idealized spatial relationship between salt-marsh floral and foraminiferal zones, where the landward margin of the marsh gradually migrates inland in response to sea-level rise. This model predicts that transgression will result in persistent and possibly expanded salt marshes at the surface, depending on a variety of factors including sediment supply, hydrologic conditions, tidal range, and rate of sea-level rise. However, in areas with abundant sediment supply and slow rates of sea- level rise, the extent of back-barrier salt marshes may decline over time as the barrier-spits mature. Sea level around the northeast coast of Newfoundland is rising at a very slow rate during the late Holocene (flora. These transitions are interpreted to reflect the progradation of the spit, decreased tidal exchange in the back-barrier, and increased influence of freshwater streams discharging into the back-barrier setting. Decreased marine influence on the back-barrier environment leads to a floral and faunal shift associated with a regressive stratigraphy in an area experiencing sea-level rise. For studies of Holocene sea-level change requiring salt-marsh stratigraphic records, it is necessary to account for changing micro-environments to locate sites appropriate for study; salt marshes may play an important role in defining the record, but may not exist at the surface to guide investigation.

  7. Stratigraphic structure of the B1 Tertiary tectonostratigraphic unit in eastern Slovenia

    Directory of Open Access Journals (Sweden)

    Bogomir Jelen

    2002-06-01

    Full Text Available High inconsistency and incoherence in the stratigraphy of the Slovenian upper Paleogene and lower Miocene have remained unsolved in the past 150 years. To solve the problem, we tried to rigorously conduct the authentic Galilei’s scientific method. Steps of logical and empirical verification confirmed the existence of the posited B1 Tertiary tectonostratigraphic unit, and a general chronostratigraphic model of new positional relationships of lithologic units resulted from rather good biochronostratigraphic resolution achieved by nannoplankton and planktonic foraminifera biostratigraphy. The application of principles of newly developed fields in science helped us to avoid errors in transmission of messages (to reduce noise from the source (rock to the concept formation,which had been done previously. This in turn has strongly reduced inconsistency andincoherence (high information entropy = uncertainty. The released amount of information enabled us to answer also questions that reached beyond the original difficulty, e.g.: is the tectonostratigraphic structure of eastern Slovenia a manifestation of plate tectonics processes, and of which ones, are theories of continental escape in the Alps and associated dissection and offset of the formerly uniform Slovenian-Hungarian Paleogene basin tenableor not, are then there in the B1 stratigraphic equivalents of the Hungarian Paleogene basin formations, where are the important Eocene / Oligocene, Paleogene / Neogene, Rupelian / Chattian and Kiscellian / Egerian boundaries in Slovenia, and is there acontinuation of the B1 in Croatia and in the Mid-Hungarian tectonic zone?

  8. New SHRIMP zircon results from Broken Hill: towards robust stratigraphic and event timing

    International Nuclear Information System (INIS)

    Page, R.W.; Stevens, B.P.J.

    1999-01-01

    Full text: Zircon U-Pb SHRIMP geochronology is a powerful means of elucidating geological ages, providing that it is integrated with unequivocal field constraints, and providing that the fundamental assumptions which are behind any isotopic dating methods are geologically validated. In an attempt to better quantify the timing of Broken Hill's complex history and to reduce some current uncertainties, we report initial results from a new U-Pb SHRIMP investigation. This program was planned within the background of our own disparate stratigraphic and structural approaches to Broken Hill geology, and with objectives to (a) benchmark our new age results with those of previous workers as well as our own previous work in the Broken Hill Group, (b) evaluate and test the evidence for reported Archaean basement terrain, (c) date stratigraphic units in the upper parts of the Willyama Supergroup, (d) better constrain the timing of deformational events. Our U-Pb SHRIMP work on zircons from layered paragneisses in the Redan Geophysical Zone near Farmcote was catalysed by Nutman and Ehlers' (1998a) preferred interpretation that these 'strondhjemitic' gneisses represent an original ∼2650 Ma protolith. Our work finds zircon provenance age signatures typical of almost all ca. 1700 Ma metasediments, whether in the Broken Hill Block or other Australian Palaeoproterozoic settings. This therefore suggests that the rocks are not Archaean basement, but are part of a Thackaringa Group package possibly deposited about 1705-1710 Ma ago. New SHRIMP work on the Alma Gneiss provides a magmatic age of 1704±3 Ma, and a minimum stratigraphic age for host Thackaringa Group. This result is within error of our ages for other granitoids (1703±3 Ma, 1704±3 Ma) in the same stratigraphic position near Farmcote. As the Thackaringa Group is no more than 1000-1500 metres thick and includes 1710-1700 Ma detrital zircons, pan of the Alma Gneiss intrusion may well have been shallowly intruded, and akin to

  9. Stratigraphic and morphologic signatures of continental shelves, IGC 2016, Cape Town: an introduction

    Science.gov (United States)

    Green, A. N.; Cooper, J. A. G.

    2018-02-01

    This special issue of Geo-Marine Letters comprises seven contributions to the session "Stratigraphic and morphologic signatures of continental shelves" of the 35th International Geological Congress held in Cape Town (Republic of South Africa) on 27 August-4 September 2016. There is an additional article not presented at the conference but falling into the same general theme. The guest editors are A.N. Green and J.A.G. Cooper. The eight articles address several contemporary themes in continental shelf geology. They include the role of antecedent conditioning on the development of shelf stratigraphy and geomorphology; erosion of submerged shorelines and their preservation during (stepped) postglacial sea-level rise; the role of glacial processes (e.g. iceberg scouring during ice-sheet retreat); and the utility of archival data in addressing contemporary issues such as Holocene climate change and global oceanographic circulation systems. The continental shelf holds important information for understanding past and present global circulation and earth-ice-atmosphere interactions including sea-level change. It is hoped that these themes will spur further research that is slowly coming to the fore in several new and innovative mapping and exploration programmes emerging from an increasing number of coastal nations.

  10. The geostatistical approach for structural and stratigraphic framework analysis of offshore NW Bonaparte Basin, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Wahid, Ali, E-mail: ali.wahid@live.com; Salim, Ahmed Mohamed Ahmed, E-mail: mohamed.salim@petronas.com.my; Yusoff, Wan Ismail Wan, E-mail: wanismail-wanyusoff@petronas.com.my [Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610 Tronoh, Perak (Malaysia); Gaafar, Gamal Ragab, E-mail: gaafargr@gmail.com [Petroleum Engineering Division, PETRONAS Carigali Sdn Bhd, Kuala Lumpur (Malaysia)

    2016-02-01

    Geostatistics or statistical approach is based on the studies of temporal and spatial trend, which depend upon spatial relationships to model known information of variable(s) at unsampled locations. The statistical technique known as kriging was used for petrophycial and facies analysis, which help to assume spatial relationship to model the geological continuity between the known data and the unknown to produce a single best guess of the unknown. Kriging is also known as optimal interpolation technique, which facilitate to generate best linear unbiased estimation of each horizon. The idea is to construct a numerical model of the lithofacies and rock properties that honor available data and further integrate with interpreting seismic sections, techtonostratigraphy chart with sea level curve (short term) and regional tectonics of the study area to find the structural and stratigraphic growth history of the NW Bonaparte Basin. By using kriging technique the models were built which help to estimate different parameters like horizons, facies, and porosities in the study area. The variograms were used to determine for identification of spatial relationship between data which help to find the depositional history of the North West (NW) Bonaparte Basin.

  11. Ages of subsurface stratigraphic intervals in the Quaternary of Enewetak Atoll, Marshall Islands

    Science.gov (United States)

    Szabo, B. J.; Tracey, J.I.; Goter, E.R.

    1985-01-01

    Drill cores of Enewetak Atoll, Marshall Islands, reveal six stratigraphic intervals, numbered in downward sequence, which represent vertical coral growth during Quaternary interglaciations. Radiocarbon dates indicate that the Holocene sea transgressed the emergent reef platform by about 8000 yr B.P. The reef grew rapidly upward (about 5 to 10 mm/yr) until about 6500 yr B.P. Afterward vertical growth slowed to about 0.5 mm/yr, then lateral development became dominant during the last several thousand years. The second interval is dated at 131,000 ?? 3000 yr B.P. by uranium series. This unit correlates with oxygen-isotope substage 5e and with terrace VIIa of Huon Peninsula, New Guinea, and of Main Reef-2 terrace at Atauro Island. The third interval is not dated because corals were recrystallized and it is tentatively correlated with either oxygen-isotope stages 7 or 9. The age of the fourth interval is estimated at 454,000 ?? 100,000 yr B.P. from measured 234U 238U activity ratios. This unit is correlated with either oxygen-isotope stage 9, 11, or 13. ?? 1985.

  12. Nordkorea kan endelig ramme USA

    DEFF Research Database (Denmark)

    Jakobsen, Peter Viggo

    2017-01-01

    Nordkoreas evne til at nå USA baner vej for en forhandlet løsning, fordi præsident Trump ikke har andre alternativer. Krig vil koste over en million døde, og Kina er imod effektive sanktioner. Det nødvendige pres for at få USA til forhandlingsbordet er nu på plads.......Nordkoreas evne til at nå USA baner vej for en forhandlet løsning, fordi præsident Trump ikke har andre alternativer. Krig vil koste over en million døde, og Kina er imod effektive sanktioner. Det nødvendige pres for at få USA til forhandlingsbordet er nu på plads....

  13. Using Outcrop Exposures on the Road to Yellowknife Bay to Build a Stratigraphic Column, Gale Crater, Mars

    Science.gov (United States)

    Stack, K. M.; Grotzinger, J. P.; Sumner, D.; Ehlmann, B. L.; Milliken, R. E.; Eigenbrode, J. L.; Gupta, S.; Williams, R. M. E.; Kah, L. C.; Lewis, K. W.

    2013-01-01

    Since landing in Gale Crater on August 5, 2012, the Curiosity rover has driven 450 m east, descending approximately 15 m in elevation from the Bradbury landing site to Yellowknife Bay. Outcrop exposure along this drive has been discontinuous, but isolated outcrops may represent windows into underlying inplace stratigraphy. This study presents an inventory of outcrops targeted by Curiosity (Figs. 1-2), grouped by lithological properties observed in Mastcam and Navcam imagery. Outcrop locations are placed in a stratigraphic context using orbital imagery and first principles of stratigraphy. The stratigraphic models presented here represent an essential first step in understanding the relative age relationships of lithological units encountered at the Curiosity landing site. Such observations will provide crucial context for assessing habitability potential of ancient Gale crater environments and organic matter preservation.

  14. FrogwatchUSA

    Science.gov (United States)

    Droege, S.

    2002-01-01

    full text: Frogs and toads are perhaps the most approachable and available of all our wildlife. In many, if not most places, they are abundant. In wetter parts of the East, almost anyone outside on a warm rainy night in spring will hear their dream-like calls, bellows, trills and snores. Even in the deserts of the Southwest, a nocturnal trip after a summer monsoon will yield toads moving across the roads toward a cacophonous orgy of mating and calling in the roadside ditches and desert pools. Birds share with frogs and toads this same sense of presence in our daily lives. But the difference is that birds are like the attractive neighbor who just never gives you the time of day, while frogs are more like the troglodyte who appears regularly to chat, philosophize, and have a beer. Uninvited, frogs appear in our water gardens, toads are on our stoops in the morning, we catch them when we are kids, raise their babies in the aquarium, and feel sorry when we find we have run them over with the lawnmower. When concerns about declining populations of amphibians reached the mass media, the Secretaries' office became involved. In addition to using traditional research mechanisms to investigate the problem, the Secretary also wanted to involve the public directly. The combination of high public appeal and the relative ease with which frog calls can be learned made a large-scale monitoring program for frogs and toads possible. What emerged was a program called Frogwatch USA, modeled after a successful Canadian program with a similar name. A web site was created (www.frogwatch.org) that presented potential frogwatchers with directions and a way to register their site online as well as enter their data. Observers chose where to count frogs depending on what they felt was important. For some it was their backyard, others chose vulnerable wetlands in their neighborhoods, or spots on local refuges and parks. Initially funded at $8,000 a year and then after two years increased to

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

    DEFF Research Database (Denmark)

    Kalsbeek, F.; Frei, Robert

    2010-01-01

    The Neoproterozoic Volta basin of Ghana (not, vert, similar115,000 km2; depth up to 5–7 km) consists of flat-lying sedimentary rocks, mainly sandstones that unconformably overlie the crystalline basement of the West-African craton. The stratigraphical column has been subdivided into three main...... and Obosum Groups is used to solve one of the outstanding controversies regarding the stratigraphy of the Volta basin....

  16. Spectral and stratigraphic mapping of hydrated minerals associated with interior layered deposits near the southern wall of Melas Chasma, Mars

    Science.gov (United States)

    Liu, Yang; Goudge, Timothy A.; Catalano, Jeffrey G.; Wang, Alian

    2018-03-01

    Orbital remote sensing data acquired from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard Mars Reconnaissance Orbiter (MRO), in conjunction with other datasets, are used to perform detailed spectral and stratigraphic analyses over a portion of south Melas Chasma, Mars. The Discrete Ordinate Radiative Transfer (DISORT) model is used to retrieve atmospherically corrected single scattering albedos from CRISM I/F data for mineral identification. A sequence of interbedded poly- and monohydrated sulfates associated with interior layered deposits (ILDs) is identified and mapped. Analyses from laboratory experiments and spectral unmixing of CRISM hyperspectral data support the hypothesis of precipitation and dehydration of multiple inputs of complex Mg-Ca-Fe-SO4-Cl brines. In this scenario, the early precipitated Mg sulfates could dehydrate into monohydrated sulfate due to catalytic effects, and the later-precipitated Mg sulfates from the late-stage "clean" brine could terminate their dehydration at mid-degree of hydration to form a polyhydrated sulfate layer due to depletion of the catalytic species (e.g., Ca, Fe, and Cl). Distinct jarosite-bearing units are identified stratigraphically above the hydrated sulfate deposits. These are hypothesized to have formed either by oxidation of a fluid containing Fe(II) and SO4, or by leaching of soluble phases from precursor intermixed jarosite-Mg sulfate units that may have formed during the later stages of deposition of the hydrated sulfate sequence. Results from stratigraphic analysis of the ILDs show that the layers have a consistent northward dip towards the interior of the Melas Chasma basin, a mean dip angle of ∼6°, and neighboring strata that are approximately parallel. These strata are interpreted as initially sub-horizontal layers of a subaqueous, sedimentary evaporite deposits that underwent post-depositional tilting from slumping into the Melas Chasma basin. The interbedded hydrated sulfate

  17. USA pelgab Hiina tehnoloogialuuret / Tõnis Arnover

    Index Scriptorium Estoniae

    Arnover, Tõnis, 1952-

    2005-01-01

    Hiina Ameerika-vastasest majandusluurest. USA luureameti andmetel on USA-s loodud üle kolme tuhande Hiina firma, kelle ülesandeks on tööstusliku või sõjalise tehnoloogia hankimine. Vt. samas: Hiina firmad ostavad üha suuremaid USA ettevõtteid

  18. Stratigraphic dictionary of the mesozoic and cenozoic deposits of the western Siberian lowland. Stratigraficheskii slovar' mezozoiskikh i kainozoiskikh otlozhenii zapadno-Sibirskoi nizmennosti

    Energy Technology Data Exchange (ETDEWEB)

    Rostovtseva, N N

    1978-01-01

    The dictionary contains 655 descriptions of stratigraphic subdivisions (series, suites, subsuites, layers, packets, horizons, strata) of Triassic, Jurassic, Cretaceous, Tertiary, Neogene, and Quaternary deposits of the western Siberian lowland. Also presented are maps indicating the demarcation limits of all of the adopted stratigraphic subdivisions (Appendices 1 to 14), and correlative stratigraphic diagrams (Appendices 15 to 21). The dictionary may be of use as a reference manual for geologists of all fields of specialization, particularly for those working in western Siberia. 202 references, 21 figures.

  19. The stratigraphic record of Khawr Al Maqta, Abu Dhabi, United Arab Emirates

    Science.gov (United States)

    Lokier, S. W.; Herrmann, S.

    2012-04-01

    Well-constrained modern depositional analogues are vital to the development of accurate geological reservoir models. The development of realistic hydrocarbon reservoir models requires the application of high-precision, well-constrained outcrop and sub-surface data sets with accurately-documented facies geometries and depositional sequence architectures. The Abu Dhabi coastline provides the best modern analogue for the study of ramp-style carbonate depositional facies akin to those observed in the sub-surface reservoirs of the United Arab Emirates (UAE). However, all previous studies have relied on temporally limited surface datasets. This study employed thirty five shallow subsurface cores spanning the width of the Khawr Al Maqta - the narrow shallow tidal channel that separates Abu Dhabi Island from the mainland. The cores were taken over a transect measuring 1.2 km in length by 50 m wide thus providing a high-resolution record of sub-surface facies geometries in a stratigraphically complex setting. Geometries in these Pleistocene to Holocene facies are complex with interdigitating, laterally heterogeneous carbonate, siliciclastic and evaporite units represented throughout the area of the study. Carbonate facies range from molluscan rudstones to marls and are all indicative of deposition in a shallow, relatively low energy marine setting akin to that seen in the environs of Abu Dhabi Island today. Texturally mature quartz sands occur as thin lenses and as thin cross bedded or laminated horizons up to twenty five centimetres thick. Glauconitic mudstones are common and locally exhibit evidence of rootlets and desiccation cracks. Evaporites are present in the form of gypsum occurring as isolated crystals and nodules or as massive chicken-wire units in excess of three metres thick. All of these textures are consistent with evaporite development in the shallow subsurface. Early, shallow-burial diagenesis has been important. Bioclasts are pervasively leached throughout

  20. Tectonic-stratigraphic evolution of Espirito Santo Basin - Brazil; Evolucao tectono-estratigrafica da Bacia do Espirito Santo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Eric Zagotto; Fernandes, Flavio L.; Lobato, Gustavo; Ferreira Neto, Walter Dias [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem de Bacias (LAB2M); Petersohn, Eliane [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Brasilia, DF (Brazil)

    2008-07-01

    This paper documents the analysis of seismic data of the Espirito Santo basin obtained during the project realized through partnership between COPPE/UFRJ/Lab2M with the Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP) during 2006 and 2007. The major objective of the seismic data interpretation in the project was to define the main structural and stratigraphic features in order to build a sedimentation model and a tectonic-stratigraphic evolution model of the Espirito Santo basin. Thus, the sedimentary package has been divided into eight genetic units (UN), grouped into five third order stratigraphic sequences, namely: UN-B, represented by siliciclastics rocks of the rift stage and evaporitic sag-rift stage, deposited during the Aptian; UN-C, which represents the carbonatic rocks deposited in a marine environment, and siliciclastics rocks located in the proximal portions during the Albian; and UN-D, represented by sediments, composed mainly by pelites, deposited in between the Cenomanian and Recent, and includes the Eocene volcanic event, which one changed the sedimentation pattern of the basin. (author)

  1. Fine reservoir structure modeling based upon 3D visualized stratigraphic correlation between horizontal wells: methodology and its application

    Science.gov (United States)

    Chenghua, Ou; Chaochun, Li; Siyuan, Huang; Sheng, James J.; Yuan, Xu

    2017-12-01

    As the platform-based horizontal well production mode has been widely applied in petroleum industry, building a reliable fine reservoir structure model by using horizontal well stratigraphic correlation has become very important. Horizontal wells usually extend between the upper and bottom boundaries of the target formation, with limited penetration points. Using these limited penetration points to conduct well deviation correction means the formation depth information obtained is not accurate, which makes it hard to build a fine structure model. In order to solve this problem, a method of fine reservoir structure modeling, based on 3D visualized stratigraphic correlation among horizontal wells, is proposed. This method can increase the accuracy when estimating the depth of the penetration points, and can also effectively predict the top and bottom interfaces in the horizontal penetrating section. Moreover, this method will greatly increase not only the number of points of depth data available, but also the accuracy of these data, which achieves the goal of building a reliable fine reservoir structure model by using the stratigraphic correlation among horizontal wells. Using this method, four 3D fine structure layer models have been successfully built of a specimen shale gas field with platform-based horizontal well production mode. The shale gas field is located to the east of Sichuan Basin, China; the successful application of the method has proven its feasibility and reliability.

  2. A Stratigraphic Pollen Record from a Late Pleistocene Cypress Forest, Northern Gulf of Mexico Continental Shelf

    Science.gov (United States)

    Reese, A.; Harley, G. L.; DeLong, K. L.; Bentley, S. J.; Xu, K.; Gonzalez Rodriguez, S. M.; Truong, J. T.; Obelcz, J.; Caporaso, A.

    2017-12-01

    Stratigraphic pollen analysis was performed on a layer of preserved peat found near the bottom of a 4.75m vibracore taken in 18m of water off the coast of Orange Beach, Alabama. The core was taken from a site where the remains of a previously buried bald cypress (Taxodium distichum) forest was discovered after wave action, likely from Hurricane Ivan in 2004, scoured and removed the overlying Holocene/late Pleistocene sand sheet. Many of the cypress stumps found at the site are still in growth position, and rooted in the preserved terrestrial soils below. Radiocarbon dating of the peat recovered in core DF1 suggests that the sediment is likely Marine Isotope Stage 3 (MIS 3), or earlier. We hypothesize that the site was quickly buried and preserved by floodplain aggradation associated with sea-level rise that occurred near the end of MIS 3. This rare find provides an opportunity to study in situ fossil pollen from a glacial refugium in the Northern Gulf of Mexico. Pollen results from the lowermost sections within the peat layer show an assemblage consistent with a bald cypress/tupelo gum (Nyssa aquatica) backwater. This is eventually replaced by a more open, possibly brackish, environment, dominated by grasses (Poaceae) and sedges (Cyperaceae). During this change however, there is a brief but very interesting period where the pollen assemblage is likely analogous to the modern day Atlantic Coastal Plain Blackwater Levee/Bar Forests of North and South Carolina. In this modern assemblage, as well as the core samples, birch (Betula), oak (Quercus) and bald cypress are the dominant taxa, along with a strong presence of alder (Alnus), grasses and sedges. We hypothesize that these bar forests formed on areas of higher ground, which resulted from floodplain aggradation that accompanied sea level rise at the end of MIS 3.

  3. THE BALNEARY RESOURCE, A GENERATOR OF BUILT HERITAGE. THE STRATIGRAPHIC FEATURES OF HERCULANE BATHS

    Directory of Open Access Journals (Sweden)

    S. SPÂNU

    2012-03-01

    Full Text Available The balneary resource, a generator of built heritage. The stratigraphic features of Herculane Baths. The exploitation of natural resources, regardless of type, usually consists of two phases: firstly, the development of exploitation processes and secondly the development of exploitation structures – elements or built structures intended for the processing of the concerned natural resources. Many such structures have been declared architectural heritage monuments due to their historical, documentary, representative and aesthetical value, examples being numerous and varied. Water is the main resource that dictates the occurrence and development of human settlements and creates various typologies that derive from the accessibility, exploitation methods, and adaptation to the conditions and characteristics of the resource. With a peculiar evolution in terms of the dynamics of the binomial composed of natural resource and architectural heritage resource, mineral resources (especially balneal waters fall in a distinct category: although mainly utilitarian in function, they have also cultural, aesthetic and even religious purposes. Besides their curative properties, spa mineral waters can be used as is, in many cases directly from the source, this being the explanation why they have generated such great and continuous interest - forming today a highly stratified built heritage background. Keeping in mind the sustainable development for a medium or a long period of time, an analysis of the interrelations between the balneal natural resource and the deriving architectural heritage is necessary. The purpose of such analysis is determining the limitations of exploitation and identifying the optimal means of safeguarding both elements, the natural water resource and the anthropogenic one, for a more rational territory management.

  4. Stratigraphic charcoal analysis on petrographic thin sections: Application to fire history in northwestern Minnesota

    Science.gov (United States)

    Clark, James S.

    1988-07-01

    Results of stratigraphic charcoal analysis from thin sections of varved lake sediments have been compared with fire scars on red pine trees in northwestern Minnesota to determine if charcoal data accurately reflect fire regimes. Pollen and opaque-spherule analyses were completed from a short core to confirm that laminations were annual over the last 350 yr. A good correspondence was found between fossil-charcoal and fire-scar data. Individual fires could be identified as specific peaks in the charcoal curves, and times of reduced fire frequency were reflected in the charcoal data. Charcoal was absent during the fire-suppression era from 1920 A.D. to the present. Distinct charcoal maxima from 1864 to 1920 occurred at times of fire within the lake catchment. Fire was less frequent during the 19th century, and charcoal was substantially less abundant. Fire was frequent from 1760 to 1815, and charcoal was abundant continuously. Fire scars and fossil charcoal indicate that fires did not occur during 1730-1750 and 1670-1700. Several fires occurred from 1640 to 1670 and 1700 to 1730. Charcoal counted from pollen preparations in the area generally do not show this changing fire regime. Simulated "sampling" of the thin-section data in a fashion comparable to pollen-slide methods suggests that sampling alone is not sufficient to account for differences between the two methods. Integrating annual charcoal values in this fashion still produced much higher resolution than the pollen-slide method, and the postfire suppression decline of charcoal characteristic of my method (but not of pollen slides) is still evident. Consideration of the differences in size of fragments counted by the two methods is necessary to explain charcoal representation in lake sediments.

  5. Preliminary stratigraphic and petrologic characterization of core samples from USW-G1, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Waters, A.C.; Carroll, P.R.

    1981-11-01

    Tuffs of the Nevada Test Site are currently under investigation to determine their potential for long-term storage of radioactive waste. As part of this program, hole USW-G1 was drilled to a depth of 6000 ft below the surface, in the central part of the Yucca Mountain area, Nevada Test Site, Nevada. Petrographic study of the USW-G1 core is presented in this report and shows the tuffs (which generally were variably welded ash flows) are partly recrystallized to a variety of secondary minerals. The important alteration products are zeolites (heulandite, clinoptilolite, mordenite and analcime), smectite clays with minor interstratified illite, albite, micas, potassium feldspar, and various forms of silica. Iijima's zeolite zones I through IV of burial metamorphism can be recognized in the core. Zeolites are first observed at about the 1300-ft depth, and the high-temperature boundary of zeolite stability in this core occurs at about 4350 ft. Analcime persists, either metastably or as a retrograde mineral, deeper in the core. The oxidation state of Fe-Ti oxide minerals, through most of the core, increases as the degree of welding decreases, but towards the bottom of the hole, reducing conditions generally prevail. Four stratigraphic units transected by the core may be potentially favorable sites for a waste repository. These four units, in order of increasing depth in the core, are (1) the lower cooling unit of the Topopah Spring Member, (2) cooling unit II of the Bullfrog Member, (3) the upper part of the Tram tuff, and (4) the Lithic-rich tuff

  6. The Oligocene-Miocene stratigraphic evolution of the Majella carbonate platform (Central Apennines, Italy)

    Science.gov (United States)

    Brandano, Marco; Cornacchia, Irene; Raffi, Isabella; Tomassetti, Laura

    2016-03-01

    The stratigraphic architecture of the Bolognano Formation documents the evolution of the Majella carbonate platform in response to global and local changes that affected the Mediterranean area during the Oligocene-Miocene interval. The Bolognano Formation consists of a homoclinal ramp that developed in a warm, subtropical environment. Five different lithofacies associations have been identified: Lepidocyclina calcarenites, cherty marly limestones, bryozon calcarenites, hemipelagic marls and marly limestones, and Lithothamnion limestones. Each association corresponds to a single lithostratigraphic unit except for the Lepidocyclina calcarenites that form two distinct lithostratigraphic units (Lepidocyclina calcarenites 1 and 2). These six units reflect alternation of shallow-water carbonate production and drowning. Specifically, two of the three stages of shallow-water carbonate production regard the development of wide dune fields within the middle ramp, one stage dominated by red algae and a sea-grass carbonate factory, whereas the two drowning phases are represented by marly cherty limestones and calcareous marls. A new biostratigraphic framework for Bolognano Formation is presented, based on high-resolution analysis of calcareous nannofossil assemblages, which proved to be very useful for biostratigraphic constraints also in shallow-water settings. Using this approach, we have linked the first drowning phase, late Chattian-Aquitanian p.p. in age, to western Mediterranean volcanism and the Mi-1 event, and the second drowning phase, late Burdigalian-Serravallian in age, to the closure of the Indo-Pacific passage and the occurrence of the global Monterey event. These results permit a new deciphering, in terms of sequence stratigraphy, of the Bolognano Formation that is interpreted as a 2nd-order super-sequence that can be subdivided into 3 transgressive-regressive sequences.

  7. Sequence stratigraphic analysis and the origins of Tertiary brown coal lithotypes, Latrobe Valley, Gippsland Basin, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Holdgate, G R; Kershaw, A P; Sluiter, I R.K. [Monash University, Clayton, Vic. (Australia). Dept. of Earth Sciences

    1995-11-01

    Sequence analysis methods have been applied to the onshore Gippsland Basin and to the Latrobe Valley Group coal measures. In the east of the Latrobe Valley evidence for marine transgressions into the coal measures are recorded in most of the interseam sediment splits by the presence of contained foraminifer and dinoflagellates. To the west these splits pinch out into continuous coal. However, they can be followed westwards as enhanced organic sulphur levels along sharply defined boundaries between light coal lithotypes below and dark coal lithotypes above. The dark lithotype immediately overlying each of these boundaries contains the highest sulphur value and warmer climate pollen assemblages. Colorimeter and lithotype logging supports an upwards lightening cyclicity to coal colour at 12-20 m intervals through the approx. 100 m thick seams, with cycle boundaries defined at sharp planar to undulating surfaces. The lightening upward lithotype cycles together with their unique boundary conditions are interpreted as parasequences and parasequence boundaries respectively. Each major coal seam can comprise up to five parasequences and is interpreted to represent deposition during an outbuilding high stand systems tract at one of several maximum periods of Tertiary coastal onlap. Stratigraphic correlation of the sequence boundaries identified in the coal measures to the internationally dated marine Seaspray Group, provides a basis for chronostratigraphic correlation of the coal successions to the coastal onlap charts of Haq et al (1989). It appears that each major seam is confined to high standards of third order eustatic cycles. It follows that the lithotype cycles that comprise each seam are related to fourth order eustatic cycles. 49 refs., 11 figs., 1 tab.

  8. Preliminary stratigraphic and petrologic characterization of core samples from USW-G1, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Waters, A.C.; Carroll, P.R. (eds.)

    1981-11-01

    Tuffs of the Nevada Test Site are currently under investigation to determine their potential for long-term storage of radioactive waste. As part of this program, hole USW-G1 was drilled to a depth of 6000 ft below the surface, in the central part of the Yucca Mountain area, Nevada Test Site, Nevada. Petrographic study of the USW-G1 core is presented in this report and shows the tuffs (which generally were variably welded ash flows) are partly recrystallized to a variety of secondary minerals. The important alteration products are zeolites (heulandite, clinoptilolite, mordenite and analcime), smectite clays with minor interstratified illite, albite, micas, potassium feldspar, and various forms of silica. Iijima`s zeolite zones I through IV of burial metamorphism can be recognized in the core. Zeolites are first observed at about the 1300-ft depth, and the high-temperature boundary of zeolite stability in this core occurs at about 4350 ft. Analcime persists, either metastably or as a retrograde mineral, deeper in the core. The oxidation state of Fe-Ti oxide minerals, through most of the core, increases as the degree of welding decreases, but towards the bottom of the hole, reducing conditions generally prevail. Four stratigraphic units transected by the core may be potentially favorable sites for a waste repository. These four units, in order of increasing depth in the core, are (1) the lower cooling unit of the Topopah Spring Member, (2) cooling unit II of the Bullfrog Member, (3) the upper part of the Tram tuff, and (4) the Lithic-rich tuff.

  9. Stratigraphic units overlying the Zambales Ophiolite Complex (ZOC) in Luzon, (Philippines): Tectonostratigraphic significance and regional implications

    Science.gov (United States)

    Queaño, Karlo L.; Dimalanta, Carla B.; Yumul, Graciano P.; Marquez, Edanjarlo J.; Faustino-Eslava, Decibel V.; Suzuki, Shigeyuki; Ishida, Keisuke

    2017-07-01

    The Zambales Ophiolite Complex (ZOC) on the island of Luzon, Philippines is one of the most well-studied crust-mantle sequences in the region. Several massifs comprise the ZOC, one of which is the Coto Block overlain by clastic sedimentary units previously dated as Eocene. Geochronologic studies from diabase, granodiorites and other late-stage magmatic products similarly yielded the same age. Succeeding tectonic models have therefore all been grounded on the assumption that the entire ZOC is Eocene. Recent investigations, however, revealed the presence of chert blocks within the Early to Middle Miocene clastic formation overlying the Acoje Block in the northern part of the ophiolite complex. Radiolarians extracted from the cherts yielded a stratigraphic range that suggests a Late Jurassic to Early Cretaceous age. The recognition of a much older age than previously reported of the ZOC warrants a re-examination of its actual distribution and genesis. Correlating with other similarly-aged ophiolites, we suggest defining a western Mesozoic ophiolite belt, largely extending from the west-central portion of the archipelago to the northeastern tip of Luzon island. Tentatively, we attribute the Mesozoic ophiolitic and associated rocks in western Luzon to an arc-continent collision involving the Philippine Mobile Belt and the Palawan Microcontinental Block. In addition, differences in the clastic compositions of the Cenozoic sedimentary formations provide material not only for deciphering the ZOC's unroofing history but also for constraining the timing of province linkage. The intermittent appearance of lithic fragments and detrital minerals from the ophiolite in the units of the Middle Miocene Candelaria Limestone and the Late Miocene to Early Pliocene Sta. Cruz Formation indicates significant but geographically variable contributions from the ophiolite complex. In the northern Zambales Range, the Sta. Cruz Formation caps the Coto Block and the Acoje Block of the ZOC

  10. A stratigraphic model to support remediation of groundwater contamination in the southern San Francisco Bay area

    International Nuclear Information System (INIS)

    Steinpress, M.G.

    1993-01-01

    Some early regional studies in the southern San Francisco Bay Area applied the term 'older bay mud' to Wisconsin and older deposits thought to be estuarine in origin. This outdated interpretation has apparently contributed to an expectation of laterally-continuous aquifers and aquitards. In fact, heterogeneous alluvial deposits often create complex hydrogeologic settings that defy simple remedial approaches. A more useful stratigraphic model provides a foundation for conducting site investigations and assessing the feasibility of remediation. A synthesis of recent regional studies and drilling results at one site on the southwest margin of the Bay indicate that the upper quaternary stratigraphy consists of four primary units in the upper 200 feet of sediments (oldest to youngest): (1) Illinoian glacial-age alluvium (an important groundwater source); (2) Sangamon interglacial-age deposits, which include fine-grained alluvial deposits and estuarine deposits equivalent to the Yerba Buena Mud (a regional confining layer); (3) Wisconsin glacial-age alluvial fan and floodplain deposits; and (4) Holocene interglacial-age sediments, which include fine-grained alluvial and estuarine deposits equivalent to the 'younger bay mud'. Remedial investigations generally focus on groundwater contamination in the Wisconsin and Holocene alluvial deposits. Detailed drilling results indicate that narrow sand and gravel channels occur in anastomosing patterns within a Wisconsin to Holocene floodplain sequence dominated by interchannel silts and clays. The identification of these small-scale high-permeability conduits is critical to understanding and predicting contaminant transport on a local scale. Discontinuous site-specific aquitards do not provide competent separation where stacked channels occur and the correlation of aquitards over even small distance is often tenuous at best

  11. WheelerLab: An interactive program for sequence stratigraphic analysis of seismic sections, outcrops and well sections and the generation of chronostratigraphic sections and dynamic chronostratigraphic sections

    OpenAIRE

    Adewale Amosu; Yuefeng Sun

    2017-01-01

    WheelerLab is an interactive program that facilitates the interpretation of stratigraphic data (seismic sections, outcrop data and well sections) within a sequence stratigraphic framework and the subsequent transformation of the data into the chronostratigraphic domain. The transformation enables the identification of significant geological features, particularly erosional and non-depositional features that are not obvious in the original seismic domain. Although there are some software produ...

  12. Stratigraphic constraints on the timing and emplacement of the Alika 2 giant Hawaiian submarine landslide

    Science.gov (United States)

    McMurtry, Gary M.; Herrero-Bervera, Emilio; Cremer, Maximilian D.; Smith, John R.; Resig, Johanna; Sherman, Clark; Torresan, Michael E.

    1999-01-01

    Previous work has found evidence for giant tsunami waves that impacted the coasts of Lanai, Molokai and other southern Hawaiian Islands, tentatively dated at 100 + and 200 + ka by U-series methods on uplifted coral clasts. Seafloor imaging and related work off Hawaii Island has suggested the Alika phase 2 debris avalanche as the source of the ~ 100 ka "giant wave deposits", although its precise age has been elusive. More recently, a basaltic sand bed in ODP site 842 (~ 300 km west of Hawaii) estimated at 100 ?? 20 ka has been suggested to correlate with this or another large Hawaiian landslide. Our approach to the timing and linkage of giant submarine landslides and paleo-tsunami deposits is a detailed stratigraphic survey of pelagic deposits proximal to the landslide feature, beginning with a suite of seven piston, gravity and box cores collected in the vicinity of the Alika 2 slide. We used U-series dating techniques, including excess 230Th and 210Pb profiling, high-resolution paleomagnetic stratigraphy, including continuous, U-channel analysis, δ18O stratigraphy, visual and X-ray sediment lithology, and the petrology and geochemistry of the included turbidites and ash layers. Minimum ages for the Alika phase 2a slide from detailed investigation of two of the cores are 112 ± 15 ka and 125 ± 24 ka (2σ) based on excess 230Th dating. A less precise age for the Alika phase 1 and/or South Kona slide is 242 ± 80 ka (2σ), consistent with previous geological estimates. Oxygen isotope analyses of entrained planktonic foraminifera better constrain the Alika phase 2a maximum age at 127 ± 5 ka, which corresponds to the beginning of the stage 5e interglacial period. It is proposed that triggering of these giant landslides may be related to climate change when wetter periods increase the possibility of groundwater intrusion and consequent phreatomagmatic eruptions of shallow magma chambers. Our study indicates the contemporaneity of the Alika giant submarine landslides

  13. Stratigraphic, Granulometric and Geochemical Studies of a Major Plinian Eruption on Dominica, Lesser Antilles

    Science.gov (United States)

    Smith, A. L.; Daly, G.; Killingsworth, N.; Deuerling, K.; Schneider, S.; Fryxell, J. E.

    2008-12-01

    The island of Dominica, located in the center of the Lesser Antilles island arc has witnessed, probably within the last 100,000 years, three large volume Plinian eruptions. One of these, associated with the Morne Diablotins center, forms the Grande Savane pyroclastic flow fan, that extends off shore as a distinctive submarine feature for a distance of at least 14 km. Stratigraphical studies of road cuts and well-exposed sea cliffs indicate the fan is composed of an older unit composed of reworked deposits at the base followed by at least four sequences, based on the presence of paleosols, of block and ash flow deposits. The upper unit of block and ash flows is overlain, with no evidence of an intervening paleosol, by a sequence of ignimbrites and pumiceous surges (representing the Plinian eruption). There is no evidence of an initial Plinian fall deposit, so the lowest bed in the succession is an ignimbrite with a highly irregular base that cuts into the underlying block and ash flow deposits, the upper parts of which are colored red due to thermal effects. This lowest ignimbrite is welded (minimum porosity of 15%) throughout its thickness (maximum thickness of greater than 21 m), although a few outcrops near the margins show a thin (20-30 cm) non-welded but lithified zone beneath the welded zone. The remainder of the sequence is composed of lithified ignimbrite that can be subdivided into three units separated by pumiceous surge layers. The ignimbrite succession is overlain, with no obvious break, by a thin fall deposit containing accretionary lapilli and gas cavities, followed by three pumiceous surge deposits (lower and upper show planar stratification and the middle surge shows massive bedding); towards the north the upper two surge deposits are separated by thin pumiceous lapilli fall and ash fall deposits. This surge sequence extends laterally outside of the main area of ignimbrite deposition. The pumice clasts from the ignimbrites are andesitic in

  14. Sequence stratigraphic analysis of Cenomanian greenhouse palaeosols: A case study from southern Patagonia, Argentina

    Science.gov (United States)

    Varela, Augusto N.; Veiga, Gonzalo D.; Poiré, Daniel G.

    2012-10-01

    proximal fluvial floodplains, respectively. The palaeosol succession for the Mata Amarilla Formation can be analysed within a sequence stratigraphic scheme considering changes in depositional environments in relation to accommodation/supply conditions. The results contrast with classical models, mainly in that the palaeosols of the Mata Amarilla Formation are relatively well-developed throughout the whole sequence, including transgressive periods of relatively high aggradation rate. Also, even when during regressive episodes, when a thick palaeosol succession that marks the sequence boundary is developed in the classical models, the lack of incised valleys in this succession led to the preservation of thick palaeosol successions during lowstand conditions. The vertical and lateral palaeosol distribution identified in the Mata Amarilla Formation could be eventually extrapolated to other sequences deposited during climate optimums.

  15. Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Coring operations, core sedimentology, and lithostratigraphy

    Science.gov (United States)

    Rose, K.; Boswell, R.; Collett, T.

    2011-01-01

    In February 2007, BP Exploration (Alaska), the U.S. Department of Energy, and the U.S. Geological Survey completed the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) in the Milne Point Unit on the Alaska North Slope. The program achieved its primary goals of validating the pre-drill estimates of gas hydrate occurrence and thickness based on 3-D seismic interpretations and wireline log correlations and collecting a comprehensive suite of logging, coring, and pressure testing data. The upper section of the Mount Elbert well was drilled through the base of ice-bearing permafrost to a casing point of 594??m (1950??ft), approximately 15??m (50??ft) above the top of the targeted reservoir interval. The lower portion of the well was continuously cored from 606??m (1987??ft) to 760??m (2494??ft) and drilled to a total depth of 914??m. Ice-bearing permafrost extends to a depth of roughly 536??m and the base of gas hydrate stability is interpreted to extend to a depth of 870??m. Coring through the targeted gas hydrate bearing reservoirs was completed using a wireline-retrievable system. The coring program achieved 85% recovery of 7.6??cm (3??in) diameter core through 154??m (504??ft) of the hole. An onsite team processed the cores, collecting and preserving approximately 250 sub-samples for analyses of pore water geochemistry, microbiology, gas chemistry, petrophysical analysis, and thermal and physical properties. Eleven samples were immediately transferred to either methane-charged pressure vessels or liquid nitrogen for future study of the preserved gas hydrate. Additional offsite sampling, analyses, and detailed description of the cores were also conducted. Based on this work, one lithostratigraphic unit with eight subunits was identified across the cored interval. Subunits II and Va comprise the majority of the reservoir facies and are dominantly very fine to fine, moderately sorted, quartz, feldspar, and lithic fragment-bearing to

  16. Deciphering Depositional Signals in the Bed-Scale Stratigraphic Record of Submarine Channels

    Science.gov (United States)

    Sylvester, Z.; Covault, J. A.

    2017-12-01

    Submarine channels are important conduits of sediment transfer from rivers and shallow-marine settings into the deep sea. As such, the stratigraphic record of submarine-channel systems can store signals of past climate- and other environmental changes in their upstream sediment-source areas. This record is highly fragmented as channels are primarily locations of sediment bypass; channelized turbidity currents are likely to leave a more complete record in areas away from and above the thalweg. However, the link between the thick-bedded axial channel deposits that record a small number of flows and the much larger number of thin-bedded turbidites forming terrace- and levee deposits is poorly understood. We have developed a relatively simple two-dimensional model that, given a number of input flow parameters (mean velocity, grain size, duration of deposition, flow thickness), predicts the thickness and composition of the turbidite that is left behind in the channel and in the overbank areas. The model is based on a Rouse-type suspended sediment concentration profile and the Garcia-Parker entrainment function. In the vertical direction, turbidites tend to rapidly become thinner and finer-grained with height above thalweg, due to decreasing concentration. High near-thalweg concentrations result in thick axial beds. However, an increase in flow velocity can result in high entrainment and no deposition at the bottom of the channel, yet a thin layer of sand and mud is still deposited higher up on the channel bank. If channel thalwegs are largely in a bypass condition, relatively minor velocity fluctuations result in a few occasionally preserved thick beds in the axis, and numerous thin turbidites - and a more complete record - on the channel banks. We use near-seafloor data from the Niger Delta slope and an optimization algorithm to show how our model can be used to invert for likely flow parameters and match the bed thickness and grain size of 100 turbidites observed in a

  17. Stratigraphic architecture of hydromagmatic volcanoes that have undergone vent migration: a review of Korean case studies

    Science.gov (United States)

    Sohn, Y.

    2011-12-01

    prominent or subtle, commonly laterally extensive truncation surfaces or stratigraphic discontinuities. Careful documentation of these surfaces and discontinuities thus appears vital to proper interpretation of eruption history, morphologic evolution, and even deep-seated magmatic processes of a hydromagmatic volcano. In this respect, the technique known as 'allostratigraphy' appears useful in mapping, correlation, and interpretation of many hydrovolcanic edifices and sequences.

  18. The Pleistocene Eastern Equatorial Pacific: Insights from a New Carnegie Platform Stratigraphic Record

    Science.gov (United States)

    Gwizd, S.; Lea, D. W.

    2016-12-01

    Renewed interest in a classic Eastern Equatorial Pacific paleoceanographic site at 3° 35.85' S, 83° 57.79' W, previous site of cores V19-29 and TR163-31, prompted a re-coring in 2009 using the recently developed CDH giant piston coring system on cruise KNR195-5. Giant piston core CDH-36 (3225 m depth, 42.61 m length) nearly triples the length of previous cores at this site. When spliced together with companion multicore MC-34A (0.36 m length), these two cores generate continuous stratigraphy throughout most of the middle Pleistocene, and include recognized stratigraphic tie points ash layer "L" (Ninkovich and Shackleton, 1975) and the extinction of pink G. ruber. A new age model utilizing Bayesian analysis of 17 N. dutertrei radiocarbon dates in MC-34A and the top 3.4 m of CDH-36, and alignment of a new CDH-36 δ18O record with the LR04 benthic stack (Lisiecki and Raymo, 2005), demonstrates that this new "Carnegie Platform" (CP) record extends from 0 to 720 ka (MIS 18), tripling the timescale of previous studies, with an average sedimentation rate of 7 cm/kyr. The CP C. wuellerstorfi δ18O and δ13C records reveal strong consistencies in timing and extent of glacial and interglacial episodes with previously studied regional records. Coarse fraction percentage (%CF) ([coarse fraction/bulk dry sample] * 100) is also evaluated throughout the CP core in order to qualitatively assess dissolution cycles. The CP %CF dataset primarily records Pleistocene dissolution cycles, yet exhibits variability representative of potential local bathymetric and hydrographic effects. The timing of %CF cyclicity is consistent with processes which affect basin-wide calcium carbonate dissolution cycles, including changes in terrestrial carbon input to the oceans and changes in water mass ventilation (Shackleton, 1977; Toggweiler et al., 2006; Sexton and Barker, 2012). Establishing the stratigraphy of the CP record provides the first step towards a more thorough and extended analysis of

  19. Stratigraphic and structural compartmentalization observed within a model turbidite reservoir, Pennsylvanian Upper Jackfork Formation, Hollywood Quarry, Arkansas

    Energy Technology Data Exchange (ETDEWEB)

    Slatt, R. [Colorado School of Mines, Golden, CO (United States); Jordan, D. [Arco International Oil and Gas Co., Plano, TX (United States); Stone, C. [Arkansas Geological Commission, Little Rock, AR (United States)] [and others

    1995-08-01

    Hollywood Quarry is a 600 x 375 x 150 ft. (200 x 125 x 50m) excavation which provides a window into lower Pennsylvanian Jackfork Formation turbidite stratal architecture along the crest of a faulted anticlinal fold. A variety of turbidite facies are present, including: (a) lenticular, channelized sandstones, pebbly sandstones, and conglomerates within shale, (b) laterally continuous, interbedded thin sandstones and shales, and (c) thicker, laterally continuous shales. The sandstone and shale layers we broken by several strike-slip and reverse faults, with vertical displacements of up to several feet. This combination of facies and structural elements has resulted in a highly compartmentalized stratigraphic interval, both horizontally and vertically, along the anticlinal flexure. The quarry can be considered analogous to a scaled-down turbidite reservoir. Outcrop gamma-ray logs, measured sections, a fault map, and cross sections provide a database which is analogous to what would be available for a subsurface reservoir. Thus, the quarry provides an ideal outdoor geologic and engineering {open_quote}workshop{close_quote} venue for visualizing the potential complexities of a combination structural-stratigraphic (turbidite) reservoir. Since all forms of compartmentalization are readily visible in the quarry, problems related to management of compartmentalized reservoirs can be discussed and analyzed first-hand while standing in the quarry, within this {open_quote}model reservoir{close_quotes}. These problems include: (a) the high degree of stratigraphic and structural complexity that may be encountered, even at close well spacings, (b) uncertainty in well log correlations and log-shape interpretations, (c) variations in volumetric calculations as a function of amount of data available, and (d) potential production problems associated with specific {open_quote}field{close_quote} development plans.

  20. Ichnology applied to sequence stratigraphic analysis of Siluro-Devonian mud-dominated shelf deposits, Paraná Basin, Brazil

    Science.gov (United States)

    Sedorko, Daniel; Netto, Renata G.; Savrda, Charles E.

    2018-04-01

    Previous studies of the Paraná Supersequence (Furnas and Ponta Grossa formations) of the Paraná Basin in southern Brazil have yielded disparate sequence stratigraphic interpretations. An integrated sedimentological, paleontological, and ichnological model was created to establish a refined sequence stratigraphic framework for this succession, focusing on the Ponta Grossa Formation. Twenty-nine ichnotaxa are recognized in the Ponta Grossa Formation, recurring assemblages of which define five trace fossil suites that represent various expressions of the Skolithos, Glossifungites and Cruziana ichnofacies. Physical sedimentologic characteristics and associated softground ichnofacies provide the basis for recognizing seven facies that reflect a passive relationship to bathymetric gradients from shallow marine (shoreface) to offshore deposition. The vertical distribution of facies provides the basis for dividing the Ponta Grossa Formation into three major (3rd-order) depositional sequences- Siluro-Devonian and Devonian I and II-each containing a record of three to seven higher-order relative sea-level cycles. Major sequence boundaries, commonly coinciding with hiatuses recognized from previously published biostratigraphic data, are locally marked by firmground Glossifungites Ichnofacies associated with submarine erosion. Maximum transgressive horizons are prominently marked by unbioturbated or weakly bioturbated black shales. By integrating observations of the Ponta Grossa Formation with those recently made on the underlying marginal- to shallow-marine Furnas Formation, the entire Paraná Supersequence can be divided into four disconformity-bound sequences: a Lower Silurian (Llandovery-Wenlock) sequence, corresponding to lower and middle units of the Furnas; a Siluro-Devonian sequence (?Pridoli-Early Emsian), and Devonian sequences I (Late Emsian-Late Eifelian) and II (Late Eifelian-Early Givetian). Stratigraphic positions of sequence boundaries generally coincide with

  1. CORE-BASED INTEGRATED SEDIMENTOLOGIC, STRATIGRAPHIC, AND GEOCHEMICAL ANALYSIS OF THE OIL SHALE BEARING GREEN RIVER FORMATION, UINTA BASIN, UTAH

    Energy Technology Data Exchange (ETDEWEB)

    Lauren P. Birgenheier; Michael D. Vanden Berg,

    2011-04-11

    An integrated detailed sedimentologic, stratigraphic, and geochemical study of Utah's Green River Formation has found that Lake Uinta evolved in three phases (1) a freshwater rising lake phase below the Mahogany zone, (2) an anoxic deep lake phase above the base of the Mahogany zone and (3) a hypersaline lake phase within the middle and upper R-8. This long term lake evolution was driven by tectonic basin development and the balance of sediment and water fill with the neighboring basins, as postulated by models developed from the Greater Green River Basin by Carroll and Bohacs (1999). Early Eocene abrupt global-warming events may have had significant control on deposition through the amount of sediment production and deposition rates, such that lean zones below the Mahogany zone record hyperthermal events and rich zones record periods between hyperthermals. This type of climatic control on short-term and long-term lake evolution and deposition has been previously overlooked. This geologic history contains key points relevant to oil shale development and engineering design including: (1) Stratigraphic changes in oil shale quality and composition are systematic and can be related to spatial and temporal changes in the depositional environment and basin dynamics. (2) The inorganic mineral matrix of oil shale units changes significantly from clay mineral/dolomite dominated to calcite above the base of the Mahogany zone. This variation may result in significant differences in pyrolysis products and geomechanical properties relevant to development and should be incorporated into engineering experiments. (3) This study includes a region in the Uinta Basin that would be highly prospective for application of in-situ production techniques. Stratigraphic targets for in-situ recovery techniques should extend above and below the Mahogany zone and include the upper R-6 and lower R-8.

  2. DØ Collaboration at FNAL, USA

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. DØ Collaboration at FNAL, USA. Articles written in Pramana – Journal of Physics. Volume 62 Issue 3 March 2004 pp 561-563 Experimental Particle Physics. Search for narrow-width t t ¯ resonances in p p ¯ collisons at ( s ) = 1.8 TeV · Supriya Jain DØ Collaboration at FNAL, ...

  3. Dyslexia Laws in the USA

    Science.gov (United States)

    Youman, Martha; Mather, Nancy

    2013-01-01

    Throughout the various states of the USA, the appropriate identification of dyslexia and the timely provision of interventions are characterized by variability and inconsistency. Several states have recognized the existence of this disorder and the well-established need for services. These states have taken proactive steps to implement laws and…

  4. USA panustab keskkonda / Jeffrey Goldstein

    Index Scriptorium Estoniae

    Goldstein, Jeffrey

    2007-01-01

    USA uus energiapoliitika kava näeb ette bensiini tarbimise vähendamist järgneva 10 aasta jooksul 20%, mis omakorda vähendab ameeriklaste autodest eralduva süsihappegaasi heitmete kasvu ning vähendab sõltuvust naftast

  5. USA asekaitseminister seisab Eesti eest

    Index Scriptorium Estoniae

    2010-01-01

    Eestis visiidil viibiv USA asekaitseminister poliitika alal Michele Flournoy ütles, et pooldab koostöökohtade otsimist Moskvaga, kuid on kindlal seisukohal, et Venemaa ei tohi end siin piirkonnas kehtestada. Flournoy tunnustas Eesti panust Afganistani ning samuti liitlassuhetesse laiemalt

  6. Avian metapneumovirus in the USA

    Science.gov (United States)

    In the United States of America (USA), avian metapneumovirus (aMPV) causes an upper respiratory tract infection in turkeys; no outbreaks have been reported in commercial chicken flocks. Typical clinical signs of the disease in turkey poults include coughing, sneezing, nasal discharge, tracheal rale...

  7. A not-so-big crisis: re-reading Silurian conodont diversity in a sequence-stratigraphic framework

    Science.gov (United States)

    Jarochowska, Emilia; Munnecke, Axel

    2016-04-01

    Conodonts are extensively used in Ordovician through Triassic biostratigraphy and fossil-based geochemistry. However, their distribution in rock successions is commonly taken at face value, without taking into account their diverse and poorly understood ecology. Multielement taxonomy, ontogenetic and environmental variability, difficulties in extraction, and relative rarity all contribute to the general lack of quantitative studies on conodont stratigraphic distribution and temporal turnover. With respect to Silurian conodonts, the concept of recurrent conodont extinction events - the so called Ireviken, Mulde and Lau events - has become a standard in the stratigraphic literature. The concept has been proposed based on qualitative observations of local extirpations of open-marine pelagic or nekto-benthic taxa and temporary dominance of shallow-water species in the Silurian succession of the Swedish island of Gotland. These changes coincided with positive carbon isotope excursions, abrupt facies shifts, "blooms" of benthic fauna, and changes in reef communities, which have all been combined into a general view of Silurian bio-geochemical events. This view posits a deterministic, reproducible pattern in Silurian conodont diversity, attributed to recurrent ecological or geochemical conditions. The growing body of sequence-stratigraphic interpretations across these events in Gotland and other sections worldwide indicate that in all cases the Silurian "events" are associated with rapid global regressions. This suggests that faunal changes such as the dominance of shallow-water, low-diversity conodont fauna and the increase of benthic invertebrate diversity and abundance represent predictable consequences of the variation in the completeness of the rock record and preservation potential of different environments. Our studies in Poland and Ukraine indicate that the magnitude of change in the taxonomic composition of conodont assemblages across the middle Silurian global

  8. Quartz Ti-center in ESR dating of Xigeda formation in Sichuanand contrast with magnetic stratigraphic profiles

    International Nuclear Information System (INIS)

    Wang Ping; Li Jianping; Liu Chunru; Han Fei; Gao Lu; Wang Jiancun

    2011-01-01

    Xigeda formation is a famous fluvial-lacustrine sedimentation formed in late cenozoic in southwest China, distributed in the valley of Dadu River, Anning River, Chin-sha River etc. The age of Xigeda formation,ranges between 4.18 and 1.78 Ma BP, depending on the magnetic stratigraphy research of the stratigraphic section. Quartz Ti-center in ESR dating of sand samples from several typical sections of Xigeda formation in Sichuan shows that they are sediments in mid-pleistocene. Comparing the ESR ages and mainly normal polarity, Xigeda formation can be confirmed in Brunhes epoch according to magnetic stratigraphy. (authors)

  9. Eesti ja USA sõlmisid kokkuleppe

    Index Scriptorium Estoniae

    2017-01-01

    Kaitseminister Margus Tsahkna ja Ameerika Ühendriikide suursaadik Eestis James Melville allkirjastasid Eesti ja USA kaitsekoostöö kokkuleppe, mis hakkab reguleerima Eestis viibivate USA relvajõudude liikmete, nende pereliikmete ja lepinglaste õiguslikku staatust

  10. A promising location in Patagonia for paleoclimate and paleoenvironmental reconstructions revealed by shallow firn core from Monte San Valentin (Northern patagonia Icefield, Chile)

    DEFF Research Database (Denmark)

    Vimeux, F.; de Angelis, M.; Ginot, P.

    2008-01-01

    temperature is -11.9°C at 10-m depth allowing to expect well preserved both chemical and isotopic signals, unperturbed by water percolation. The dating of the core, on the basis of a multi-proxy approach combining annual layer counting and radionuclide measurements, shows that past environment and climate can......The study of past climate variability from ice core investigations has been largely developed both in polar areas over the past decades and, more recently, in tropical regions, specifically along the South American Andes between 0° and 20°S. However a large gap still remains at mid......-latitudes in the Southern Hemisphere. In this framework, a 15.3-m long shallow firn core has been extracted in March 2005 from the summit plateau of Monte San Valentín (3747 m, 46°35'S, 73°19'W) in the Northern Patagonia Icefield to test its potential for paleoclimate and paleoenvironmental reconstructions. The firn...

  11. Paleoenvironmental interpretation through the analysis of ostracodes and carbonate microfacies: study of the Jandaíra Formation, Upper Cretaceous, Potiguar Basin

    Directory of Open Access Journals (Sweden)

    Marcos Antonio Batista dos Santos Filho

    Full Text Available Paleoecological analyses are important tools for the reconstruction of paleoenvironments. This paper had the objective of using analysis of ostracode assemblages and carbonate microfacies of a well (Carbomil and an outcrop (Quixeré from the Jandaíra Formation, Potiguar Basin, in order to verify how they corroborate and complement the other. Two paleoenvironments for Carbomil Well (assemblages 1 and 2, respectively marine and brackish to neritic environments and one for Quixeré Outcrop (assemblage 3, marine environment were identified through the ostracode assemblage analysis. Thin section analysis allowed the identification of two different facies for Carbomil Well, i.e. bioclastic packstones to wackstones, a marine brackish or restricted marine system; and bioclastic grainstones to packstones, a normal, shallow marine system. High levels of alteration on the samples prevented an adequate analysis of Quixeré Outcrop; however, it seems to point towards a low-energy environment. Overall, information provided by the thin sections corroborate and complement data of the ostracode assemblages, which allowed a higher degree of certainty for the paleoenvironmental analysis.

  12. Stratigraphic landscape analysis, thermochronology and the episodic development of elevated, passive continental margins

    Directory of Open Access Journals (Sweden)

    Green, Paul F.

    2013-12-01

    Full Text Available The continental margin of West Greenland is similar in many respects to other elevated, passive continental margins (EPCMs around the world. These margins are characterised by extensive regions of low relief at elevations of 1–2 kilometres above sea level sloping gently inland, with a much steeper, oceanward decline, often termed a 'Great Escarpment', terminating at a coastal plain. Recent studies, based on integration of geological, geomorphological and thermochronological evidence, have shown that the high topography of West Greenland was formed by differential uplift and dissection of an Oligo-Miocene peneplain since the late Miocene, many millions of years after continental break-up between Greenland and North America. In contrast, many studies of other EPCMs have proposed a different style of development in which the high plateaux and the steep, oceanward decline are regarded as a direct result of rifting and continental separation. Some studies assume that the elevated regions have remained high since break-up, with the high topography continuously renewed by isostasy. Others identify the elevated plains as remnants of pre-rift landscapes. Key to understanding the development of the West Greenland margin is a new approach to the study of landforms, stratigraphic landscape analysis, in which the low-relief, high-elevation plateaux at EPCMs are interpreted as uplifted peneplains: low-relief surfaces of large extent, cutting across bedrock of different age and resistance, and originally graded to sea level. Identification of different generations of peneplain (re-exposed and epigene from regional mapping, combined with geological constraints and thermochronology, allows definition of the evolution leading to the formation of the modern-day topography. This approach is founded particularly on results from the South Swedish Dome, which document former sea levels as base levels for the formation of peneplains. These results support the view

  13. Revised geochronology, correlation, and dinosaur stratigraphic ranges of the Santonian-Maastrichtian (Late Cretaceous) formations of the Western Interior of North America.

    Science.gov (United States)

    Fowler, Denver Warwick

    2017-01-01

    Interbasinal stratigraphic correlation provides the foundation for all consequent continental-scale geological and paleontological analyses. Correlation requires synthesis of lithostratigraphic, biostratigraphic and geochronologic data, and must be periodically updated to accord with advances in dating techniques, changing standards for radiometric dates, new stratigraphic concepts, hypotheses, fossil specimens, and field data. Outdated or incorrect correlation exposes geological and paleontological analyses to potential error. The current work presents a high-resolution stratigraphic chart for terrestrial Late Cretaceous units of North America, combining published chronostratigraphic, lithostratigraphic, and biostratigraphic data. 40Ar / 39Ar radiometric dates are newly recalibrated to both current standard and decay constant pairings. Revisions to the stratigraphic placement of most units are slight, but important changes are made to the proposed correlations of the Aguja and Javelina formations, Texas, and recalibration corrections in particular affect the relative age positions of the Belly River Group, Alberta; Judith River Formation, Montana; Kaiparowits Formation, Utah; and Fruitland and Kirtland formations, New Mexico. The stratigraphic ranges of selected clades of dinosaur species are plotted on the chronostratigraphic framework, with some clades comprising short-duration species that do not overlap stratigraphically with preceding or succeeding forms. This is the expected pattern that is produced by an anagenetic mode of evolution, suggesting that true branching (speciation) events were rare and may have geographic significance. The recent hypothesis of intracontinental latitudinal provinciality of dinosaurs is shown to be affected by previous stratigraphic miscorrelation. Rapid stepwise acquisition of display characters in many dinosaur clades, in particular chasmosaurine ceratopsids, suggests that they may be useful for high resolution biostratigraphy.

  14. USA suursaadikuga Tallinna lahel / Katrin Kruss

    Index Scriptorium Estoniae

    Kruss, Katrin

    2007-01-01

    USA suursaadik Stanley Davis Phillips oma haridusteest, perekonnast, armastusest mere vastu, panusest isa Earl Phillipsi mööbliäri laiendamisse, golfiharrastusest, suursaadikute ettevalmistusest USA-s, suursaadiku residentsist Pirital ning uue saatkonnahoone otsingutest Tallinnas. Lisa: Stanley Davis Phillips

  15. USA andis Gruusiale vastakaid signaale / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2008-01-01

    USA välisministri Condoleezza Riceþi saabumisest Thbilisisse, et avaldada Gruusiale toetust. USA poolt antud soovitustest Gruusia president Mihhail Saakashvilile mitte jõudu kasutada ega alluda Venemaa provokatsioonidele ning hoiatustest sõjalise konflikti tagajärgede eest. USA analüütikute arvamusi

  16. 3D visualization of liquefaction-induced dune collapse in the Navajo Sandstone, Utah, USA

    Science.gov (United States)

    Ford, Colby; Nick, Kevin; Bryant, Gerald

    2015-04-01

    The eolian Navajo Sandstone outcrop on the Canyon Overlook Trail in Zion National Park in Southern Utah is dissected by modern erosion in a way which reveals a great deal of the three-dimensional architecture of a major soft-sediment deformation event. The feature is bounded below by a well-developed interdune complex made up of two superimposed carbonate lenses, above by an irregular truncational surface, and incorporates 3 - 10 m of sandstone over an approximately 2 km area. The material above the deformed interval is undeformed cross-bedded sandstone, with crossbeds downlapping onto the surface of truncation. The stratigraphic confinement of deformation and the irregularity of the upper bounding surface suggests a deformation process which created topography, which was in turn covered by the next upwind dune before it could be eroded flat. The deformed material itself is laterally segmented by a stacked succession of shear surfaces, which all strike approximately perpendicular to the paleo-wind direction and dip at decreasing angles in the down paleo-wind direction. These factors point to the collapse of a major dune into the downwind interdune area, likely initiated by liquefaction in the interdune complex. The foundering of the dune's toe into the liquefied area created a powerful lateral stress field which did not extend significantly into the subsurface. The dune collapse process has been used in the past to describe other soft-sediment deformation features in the Navajo Sandstone, but this site provides a wealth of physical details which were not previously associated with dune collapse. Shear surfaces originate in the interdune deposit as slip between laminae, then the cohesive muds provided support as they were thrust upward to angles of up to 50 degrees. The margins of the site also contain important paleoenvironmental indicators. Dinosaur tracks are exposed both at the extreme upwind and downwind margins of the interdune deposit in and slightly above

  17. Sõda, mille USA on juba kaotanud / Mart Helme

    Index Scriptorium Estoniae

    Helme, Mart, 1949-

    2003-01-01

    USA pole suutnud Iraagi-vastase sõja vajalikkust põhjendada, arvavad paljud USA poliitikavaatlejad. Rängaks diplomaatiliseks eksimuseks peetakse USA kaitseministri Donald Rumsfeldi avaldust, et USA ei vaja kellegi abi sõjas

  18. A unique fossil record from neptunian sills: the world's most extreme example of stratigraphic condensation (Jurassic, western Sicily)

    Science.gov (United States)

    Wendt, Jobst

    2017-06-01

    Neptunian sills at Rocca Busambra, a fragment of the Trapanese/Saccense Domain in western Sicily, host the most abundant ammonite and gastropod fauna which has ever been recorded from the Jurassic of the western Tethys. The fauna is dominated by parautochthonous organisms which were swept into the sills by gentle transport. Ammonites are characterized by perfect preservation and small size, a feature which is due to the predominance of microconchs but also of stunting. The most complete sill is 0.7 m thick and could be separated into 17 levels which range in age from the early Toarcian into the late Kimmeridgian, thus representing the most extreme case of palaeontologically and depositionally documented stratigraphic condensation in Earth history. The unique feature of the Rocca Busambra sills is due to the interaction of three processes: extreme stratigraphic condensation on the sea floor, weak tectonic fracturing of the host rock and repeated reopening on top of already existing sills. Contrasting percentages of gastropods in individual levels reflect sea-level oscillations which correspond to long known low- and highstands during the Jurassic of the western Tethys. Comparisons with other ammonite-bearing sill faunas reveal several similarities, but represent only short-timed phases of tectonic pulses and deposition.

  19. Preliminary stratigraphic and hydrogeologic cross sections and seismic profile of the Floridan aquifer system of Broward County, Florida

    Science.gov (United States)

    Reese, Ronald S.; Cunningham, Kevin J.

    2013-01-01

    To help water-resource managers evaluate the Floridan aquifer system (FAS) as an alternative water supply, the U.S. Geological Survey initiated a study, in cooperation with the Broward County Environmental Protection and Growth Management Department, to refine the hydrogeologic framework of the FAS in the eastern part of Broward County. This report presents three preliminary cross sections illustrating stratigraphy and hydrogeology in eastern Broward County as well as an interpreted seismic profile along one of the cross sections. Marker horizons were identified using borehole geophysical data and were initially used to perform well-to-well correlation. Core sample data were integrated with the borehole geophysical data to support stratigraphic and hydrogeologic interpretations of marker horizons. Stratigraphic and hydrogeologic units were correlated across the county using borehole geophysical data from multiple wells. Seismic-reflection data were collected along the Hillsboro Canal. Borehole geophysical data were used to identify and correlate hydrogeologic units in the seismic-reflection profile. Faults and collapse structures that intersect hydrogeologic units were also identified in the seismic profile. The information provided in the cross sections and the seismic profile is preliminary and subject to revision.

  20. Geomorphologic, stratigraphic and sedimentologic evidences of tectonic activity in Sone-Ganga alluvial tract in Middle Ganga Plain, India

    Science.gov (United States)

    Sahu, Sudarsan; Saha, Dipankar

    2014-08-01

    The basement of the Ganga basin in the Himalayan foreland is criss-crossed by several faults, dividing the basin into several sub-blocks forming horsts, grabens, or half-grabens. Tectonic perturbations along basement faults have affected the fluvial regime and extent of sediment fill in different parts of the basin during Late Quaternary. The East Patna Fault (EPF) and the West Patna Fault (WPF), located in Sone-Ganga alluvial tract in the southern marginal parts of Middle Ganga Plain (MGP), have remained tectonically active. The EPF particularly has acted significantly and influenced in evolving the geomorphological landscape and the stratigraphic architecture of the area. The block bounded by the two faults has earlier been considered as a single entity, constituting a half-graben. The present investigation (by morpho-stratigraphic and sedimentologic means) has revealed the existence of yet another fault within the half-graben, referred to as Bishunpur-Khagaul Fault (BKF). Many of the long profile morphological characters (e.g., knick-zone, low width-depth ratio) of the Sone River at its lower reaches can be ascribed to local structural deformation along BKF. These basement faults in MGP lie parallel to each other in NE-SW direction.

  1. Study on the application of seismic sedimentology in a stratigraphic-lithologic reservoir in central Junggar Basin

    Science.gov (United States)

    Yu, Yixin; Xia, Zhongmou

    2017-06-01

    This paper discusses the research idea of description for stratigraphic-lithologic reservoir based on seismic sedimentology methods. The sandstone reservoir of Jurrassic XiShanyao Formation in Junggar Basin is studied according to the theory and approaches of seismic sedimentology. By making full use of borehole data, the technologies of layer correlation based on the stratigraphic sequence framework, the forward seismic modeling, the stratal slicing and lithologic inversion are applied. It describes the range of denudation line, the distribution characteristics of sedimentary facies of the strata, the vertical and horizontal distribution of sand bodies and the favourable oil-gas bearing prospective area. The results shows that study area are dominated braided delta deposition including underwater distributary channel and distributary bay microfacies, the nip-out lines of the formation are northeast to southwest from north to south, the second Middle Jurassic sand body is the most widely distributed one among three sand bodies, the prospective oil-gas bearing area located in the south part and around the YG2 well area. The study result is effective on the practice of exploration in study area.

  2. Stratigraphical discontinuities, tropical landscape evolution and soil distribution relationships in a case study in SE-Brazil

    Directory of Open Access Journals (Sweden)

    M. Cooper

    2002-09-01

    Full Text Available On a regional summit surface in the county of Piracicaba (SP within the Peripheric Depression of São Paulo, formed of discontinued flattened tops, there is an abrupt transition between a Typic Hapludox and a Kandiudalfic Eutrudox, together with two stoneline layers. Using stratigraphical, mineralogical, and cartographic studies, this transition and the soil distribution of this surface were studied, correlating them with the different parent materials and the morphoclimatic model of landscape evolution in Southeastern Brazil. The Typic Hapludox was formed on a sandy Cenozoic deposit (Q that overlies a pellitic deposit of the Iratí formation (Pi, representing a regional erosive discordance. Westwards to the Piracicaba River, this sequence is interrupted by a diabase sill overlain by a red clayey material which gave origin to the Kandiudalfic Eutrudox. Two post-Permian depositional events were identified by the two stonelines and stratigraphical discontinuities. The first event generated the deposition of a sandy sediment in the form of levelled alveoluses on regional barriers, most of these formed by dikes and diabase sills, probably during a drier phase. The second depositional event, leading to the deposition of the red clay was probably the dissection of the previously formed pediplane during a humid climate, followed by another pedimentation process during a later, drier period.

  3. WheelerLab: An interactive program for sequence stratigraphic analysis of seismic sections, outcrops and well sections and the generation of chronostratigraphic sections and dynamic chronostratigraphic sections

    Science.gov (United States)

    Amosu, Adewale; Sun, Yuefeng

    WheelerLab is an interactive program that facilitates the interpretation of stratigraphic data (seismic sections, outcrop data and well sections) within a sequence stratigraphic framework and the subsequent transformation of the data into the chronostratigraphic domain. The transformation enables the identification of significant geological features, particularly erosional and non-depositional features that are not obvious in the original seismic domain. Although there are some software products that contain interactive environments for carrying out chronostratigraphic analysis, none of them are open-source codes. In addition to being open source, WheelerLab adds two important functionalities not present in currently available software: (1) WheelerLab generates a dynamic chronostratigraphic section and (2) WheelerLab enables chronostratigraphic analysis of older seismic data sets that exist only as images and not in the standard seismic file formats; it can also be used for the chronostratigraphic analysis of outcrop images and interpreted well sections. The dynamic chronostratigraphic section sequentially depicts the evolution of the chronostratigraphic chronosomes concurrently with the evolution of identified genetic stratal packages. This facilitates a better communication of the sequence-stratigraphic process. WheelerLab is designed to give the user both interactive and interpretational control over the transformation; this is most useful when determining the correct stratigraphic order for laterally separated genetic stratal packages. The program can also be used to generate synthetic sequence stratigraphic sections for chronostratigraphic analysis.

  4. WheelerLab: An interactive program for sequence stratigraphic analysis of seismic sections, outcrops and well sections and the generation of chronostratigraphic sections and dynamic chronostratigraphic sections

    Directory of Open Access Journals (Sweden)

    Adewale Amosu

    2017-01-01

    Full Text Available WheelerLab is an interactive program that facilitates the interpretation of stratigraphic data (seismic sections, outcrop data and well sections within a sequence stratigraphic framework and the subsequent transformation of the data into the chronostratigraphic domain. The transformation enables the identification of significant geological features, particularly erosional and non-depositional features that are not obvious in the original seismic domain. Although there are some software products that contain interactive environments for carrying out chronostratigraphic analysis, none of them are open-source codes. In addition to being open source, WheelerLab adds two important functionalities not present in currently available software: (1 WheelerLab generates a dynamic chronostratigraphic section and (2 WheelerLab enables chronostratigraphic analysis of older seismic data sets that exist only as images and not in the standard seismic file formats; it can also be used for the chronostratigraphic analysis of outcrop images and interpreted well sections. The dynamic chronostratigraphic section sequentially depicts the evolution of the chronostratigraphic chronosomes concurrently with the evolution of identified genetic stratal packages. This facilitates a better communication of the sequence-stratigraphic process. WheelerLab is designed to give the user both interactive and interpretational control over the transformation; this is most useful when determining the correct stratigraphic order for laterally separated genetic stratal packages. The program can also be used to generate synthetic sequence stratigraphic sections for chronostratigraphic analysis.

  5. Heavy mineral delineation of the Cretaceous, Paleocene, and Eocene stratigraphic sections at the Savannah River Site, Upper Coastal Plain of South Carolina

    International Nuclear Information System (INIS)

    Cathcart, E.M.; Sargent, K.A.

    1994-01-01

    The Upper Atlantic Coastal Plain of South Carolina consists of a fluvial-deltaic and shallow marine complex of unconsolidated sediments overlying the crystalline basement rocks of the North American continent. Because of the lateral and vertical variability of these sediments, stratigraphic boundaries have been difficult to distinguish. Portions of the Cretaceous, Paleocene, and eocene stratigraphic sections from cores recovered during the construction of two monitoring wells at the Savannah River Site were studied to determine if heavy mineral suites could be utilized to distinguish boundaries. The stratigraphic sections include: the Late Cretaceous Middendorf, Black Creek, and Steel Creek Formations, the Paleocene Snapp Formation, the late Paleocene-Early Eocene Fourmile Branch Formation, and the Early Eocene Congaree formation. In previous studies composite samples were taken over 2.5 ft. intervals along the cores and processed using a heavy liquid for heavy mineral recovery. During this study, heavy mineral distributions were determined by binocular microscope and the mineral identifications confirmed by x-ray diffraction analysis of hand-picked samples. The heavy mineral concentration data and grain size data were then compared to the stratigraphic boundary positions determined by other workers using more classical methods. These comparisons were used to establish the utility of this method for delineating the stratigraphic boundaries in the area of study

  6. Characterizing Structural and Stratigraphic Heterogeneities in a Faulted Aquifer Using Pump Tests with an Array of Westbay Multilevel Monitoring Wells

    Science.gov (United States)

    Johnson, B.; Zhurina, E. N.

    2001-12-01

    We are developing and assessing field testing and analysis methodologies for quantitative characterization of aquifer heterogenities using data measured in an array of multilevel monitoring wells (MLW) during pumping and recovery well tests. We have developed a unique field laboratory to determine the permeability field in a 20m by 40m by 70m volume in the fault partitioned, siliciclastic Hickory aquifer system in central Texas. The site incorporates both stratigraphic variations and a normal fault system that partially offsets the aquifer and impedes cross-fault flow. We constructed a high-resolution geologic model of the site based upon 1050 m of core and a suite of geophysical logs from eleven, closely spaced (3-10m), continuously cored boreholes to depths of 125 m. Westbay multilevel monitoring systems installed in eight holes provide 94 hydraulically isolated measurement zones and 25 injection zones. A good geologic model is critical to proper installation of the MLW. Packers are positioned at all significant fault piercements and selected, laterally extensive, clay-rich strata. Packers in adjacent MLW bracket selected hydrostratigraphic intervals. Pump tests utilized two, uncased, fully penetrating irrigation wells that straddle the fault system and are in close proximity (7 to 65 m) to the MLW. Pumping and recovery transient pressure histories were measured in 85 zones using pressure transducers with a resolution of 55 Pa (0.008 psi). The hydraulic response is that of an anisotropic, unconfined aquifer. The transient pressure histories vary significantly from zone to zone in a single MLW as well as between adjacent MLW. Derivative plots are especially useful for differentiating details of pressure histories. Based on the geologic model, the derivative curve of a zone reflects its absolute vertical position, vertical stratigraphic position, and proximity to either a fault or significant stratigraphic heterogeneity. Additional forward modeling is needed to

  7. Spatio-temporal variation in groundwater head affected by stratigraphic heterogeneity of the alluvial aquifer in Northwest India

    Science.gov (United States)

    van Dijk, W. M.; Joshi, S. K.; Densmore, A. L.; Jackson, C. R.; Sutanudjaja, E.; Lafare, A. E. A.; Gupta, S.; Mackay, J. D.; Mason, P. J.; Sinha, R.

    2017-12-01

    Groundwater is a primary source of freshwater in the alluvial aquifer system of northwestern India. Unsustainable exploitation of the groundwater resources has led to a regional hotspot in groundwater depletion. Rapid groundwater-level decline shows spatial variation, as the effects of various stresses, including precipitation, potential evapotranspiration and abstraction, are likely to be influenced by the stratigraphic and geomorphic heterogeneity between sediment fan and interfan areas (see Geomorphological map in Figure A). We used a transfer function-noise (TFN) time series approach to quantify the effect of the various stress components in the period 1974-2010, based on predefined impulse response functions (IRFs) of von Asmuth et al. (2008). The objective of this study was 1) to acquire the impulse response function of various stresses, 2) assess the spatial estimation parameter (the zeroth moment, M0) of the spatial development of the groundwater head and 3) relate the spatial M0 to the observed stratigraphic and geomorphic heterogeneity. We collected information on the groundwater head pre- and post-monsoon, the district-wise monthly precipitation and potential evapotranspiration, and we modeled the monthly abstraction rate using land-use information. The TFN identified the IRF of precipitation as well as abstraction. The IRF, summarized in the parameter M0, identified a hotspot for the abstraction stress (see M0 spatial map for abstraction in Figure B) at the margins of the Sutlej and Yamuna fans. No hotspot is observed for the precipitation stress, but the M0 for precipitation increases with distance from the Himalayan front. At larger distances from the Himalayan front, observed groundwater head rises cannot be explained by the IRFs for the abstraction and precipitation stresses. This is likely because the current TFN models do not account for other stresses, such as recharge by canal leakage, which are locally important. We conclude that the spatial

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

    Science.gov (United States)

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

    2015-04-01

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

  9. Stratigraphic cross section of measured sections and drill holes of the Neslan Formation and adjacent formations, Book Cliffs Area, Colorado and Utah

    Science.gov (United States)

    Kirshbaum, Mark A.; Spear, Brianne D.

    2012-01-01

    This study updates a stratigraphic cross section published as plate 2 in Kirschbaum and Hettinger (2004) Digital Data Series 69-G (http://pubs.usgs.gov/dds/dds-069/dds-069-g/). The datum is a marine/tidal ravinement surface within the Cozzette Sandstone Member of the Iles Formation and the Thompson Canyon Sandstone and Sulphur Canyon Sandstone Beds of the Neslen Formation. One of the cores shown was included on the original cross section, and new core descriptions have been added to the upper part of the cored interval. A new core description (S178) is included in this report. Cores are stored in the U.S. Geological Survey Core Research Facility at the Denver Federal Center, Colorado. The following information has also been added to help define the stratigraphic framework: 1) At least five claystones interpreted as altered volcanic ashes have been identified and may give future workers a correlation tool within the largely continental section. 2) Thickness and general geometry of the Sego Sandstone, Buck Tongue of the Mancos Shale, and Castlegate Sandstone have been added to provide additional stratigraphic context. 3) The geometry in the Sego Sandstone, Buck Tongue of the Mancos Shale, and Castlegate Sandstone has been added to provide additional stratigraphic context. 4) Ammonite collections are from Gill and Hail. The zone of Didymoceras nebrascense projected into the East Salt Wash area is based on correlation of the flooding surface at the base of the Cozzette Member to this point as shown in Kirschbaum and Hettinger. 5) A leaf locality of the Denver Museum of Nature and Science is shown in its approximate stratigraphic position near Thompson Canyon. 6) A dinosaur locality of the Natural History Museum of Utah is shown in the Horse Canyon area measured section at the stratigraphic position where it was extracted.

  10. Stratigraphic Stacking of Deepmarine Channel Levee Turbidites: Scales of Cyclicity and their Origin. Examples from the Laingsburg Fm. (Karoo, South Africa) and the Rosario Fm. (Baja, Mexico)

    Science.gov (United States)

    Kane, I. A.; Hodgson, D.

    2009-12-01

    Thinning upwards of the turbidite beds that form deepmarine channel levees is a common motif reported from modern and recent levees on the seafloor, from subsurface examples, and from outcropping ancient examples. Because levees are thought to be built by deposition from turbidity currents superelevated over their channel form, the volume and style of overbank deposition are controlled primarily by the relationship between levee height (i.e., thalweg to crest) and flow thickness, determining the amount of overspill. Thus stratigraphic variability of turbidite thickness is explained by some change in either or both of those factors, which may arise autocyclicly or allocyclicly. Variation in the ratio of intra-channel and extra-channel deposition can be an autocyclic stratigraphic response, e.g., in bypass dominated systems, thalweg aggradation may be retarded with respect to levee aggradation, hence as levee relief increases, flows become more confined and, given a relatively narrow range of flow sizes, the volume of overbank flow and deposit thickness decrease with stratigraphic height. However, the same stratigraphic response of the levee may occur due to allocyclic flow magnitude variation, i.e., through decreasing flow magnitude. In both the autocyclic and allocyclic case the stratigraphic response of the levee may be one of thinning upwards, even if the overall system response may be one of progradation (autocyclic bypassing case) or retrogradation (allocyclic decreasing flow magnitude case), with entirely different connotations for sequence stratigraphic interpretation. Here we report examples of different scales of bed thickness cyclicity (both thickening and thinning upward cycles superimposed by smaller scale cycles) within levees of the Rosario Formation, Baja California, Mexico, and from the Laingsburg Formation, Karoo, South Africa, and, together with published examples, discuss criteria for the recognition, and drivers of, autocyclic and allocyclic bed

  11. Review and protection possibilities of some trans-border (East Serbia-West Bulgaria stratigraphic/palaeontological geosites

    Directory of Open Access Journals (Sweden)

    Jovanović Velimir

    2012-01-01

    Full Text Available Stratigraphic/palaeontological geosites of Stara Planina Mountain in east Serbia are well developed in the area of Serbian/Bulgarian state border, where with this occassion, three sections of exeptional geological and scientific interest are selected: Jelovica, Rosomač and Senokos. These geosites represent the important localities for study of Triassic and Jurassic terrigene-carbonate deposits, for which the scientific value from the domains of palaeontology, stratigraphy and sedimentology is widely known. The aim of this work is to represent the main scientific arguments for inventory and protection of detached transborder geological sites that are unique according to their composition and content.[Projekat Ministarstva nauke Republike Srbije, br. 176008

  12. Stratigraphic sequence and sedimentary characteristics of Lower Silurian Longmaxi Formation in Sichuan Basin and its peripheral areas

    Directory of Open Access Journals (Sweden)

    Yuman Wang

    2015-03-01

    Full Text Available A high-precision sedimentary environment study of the Lower Silurian Longmaxi Formation is an important subject for shale gas exploration and development in Sichuan Basin and its surrounding areas. On the basis of outcrops and drilling data, its isochronous stratigraphic framework was built according to a particular graptolite zone and an important marker bed, and lithofacies, paleontology, calcareous content, well logging, geochemistry and other geologic information were combined to describe the sedimentary microfacies of Longmaxi Formation and its stratigraphic sequence, sedimentary evolution process and high quality shale distribution features as follows: ① with regional diachronism of the top and the bottom, the Longmaxi Formation is divided into two third-order sequences (SQ1 and SQ2, of which SQ1 is mainly an abyssal sedimentary assemblage deposited in the marine transgression period, and SQ2 is a bathyal to shallow sea sedimentary assemblage deposited in the marine regression period; ② there are eight microfacies such as deep calcareous shelf and deep argillaceous shelf in this formation and the organic-rich shale was mainly deposited in the deep water area of SQ1; and ③ from SQ1 to SQ2, the depocenter moved from the depression area in southern-eastern to northern Sichuan Basin, but the central Sichuan uplift remained an underwater one. It is concluded from this study that: ① shale gas production layers were mainly deposited in SQ1, the southern-eastern depression area was the depocenter in SQ1 and a shale gas enrichment area; and ② black shale in northern Sichuan was deposited in late SQ2, with limited distribution and relatively insufficient exploration potential, but the potential of shale gas exploration in western Hubei area is between southern-eastern and northern Sichuan Basin.

  13. Social and environmental impact of volcaniclastic flows related to 472 AD eruption at Vesuvius from stratigraphic and geoarcheological data

    Science.gov (United States)

    Di Vito, Mauro A.; de Vita, Sandro; Rucco, Ilaria; Bini, Monica; Zanchetta, Giovanni; Aurino, Paola; Cesarano, Mario; Ebanista, Carlo; Rosi, Mauro; Ricciardi, Giovanni

    2017-04-01

    There is a growing number of evidences in the surrounding plain of Somma-Vesuvius volcano which indicate that along with primary volcanic processes (i.e. fallout, pyroclastic density currents) the syn-eruptive and post-eruptive volcaniclastic remobilization has severely impacted the ancient civilizations, which flourished in the area. This represents an important starting point for understanding the future hazard related to a potential (and not remote) renewal of volcanic activity of the Campaniana volcanoes. We present geoarcheological and stratigraphic data obtained from the analysis of more than 160 sections in the Campanian plain showing the widespread impact of volcaniclastic debris flows and floods originated from the rapid remobilization of the products of the AD 472 eruption of Somma-Vesuvius, both on the environment and on the human landscape. This eruption was one of the two sub-Plinian historical events of Somma Vesuvius. This event largely impacted the northern and eastern territory surrounding the volcano with deposition of a complex sequence of pyroclastic-fallout and -current deposits. These sequences were variably affected by syn- and post-eruptive mobilization both along the Somma-Vesuvius slopes and the Apennine valleys with the emplacement of thick mud- and debris-flows which strongly modified the preexisting paleogeography of the Plain with irretrievable damages to the agricultural and urban landscape. The multidisciplinary approach to the study of the sequences permitted to reconstruct the palaeoenvironment before the eruption and the timing of the emplacement of both pyroclastic and volcanoclastic deposits. The preexisting landscape was characterized by intense human occupation, although showing strong evidences of degradation and abandonment due to the progressive decline of the Roman Empire. The impact of volcaniclastic flows continued for decades after the eruption as highlighted in the studied sequences by stratigraphic and archaeologic

  14. Stratigraphic And Lithofacies Study Of Distal Rain-Triggered Lahars: The Case Of West Coast Of Ecuador

    Science.gov (United States)

    Mulas, M.; Chunga, K.; Peña Carpio, E.; Falquez Torres, D. A.; Alcivar, R., Sr.; Lopez Coronel, M. C.

    2015-12-01

    The central zone of the coast of Ecuador at the north of Manabí Province, on the area comprised between Salango and Jama communities, is characterized by the presence of whitish to grey, centimeters to meters thick, consolidated to loose distal ash deposits. Recent archeological studies on Valdivia (3500 BC) and Manteña (800-1500 AC - Harris et al. 2004) civilizations remains link this deposits with the intense eruptive phases that afflicted Ecuador 700-900 years ago (Usselman, 2006). Stratigraphic evidences and bibliographic datations of paleosols (Estrada, 1962; Mothes and Hall, 2008), allowed to estimate that these deposits are linked with the 800 BP eruption of Quilotoa and the following eruptions of Cotopaxi. According to the Smith and Lowe classification (1991), the deposits outcropping on the coast (located at a distance greater than 160 km from the volcanic vents), varied from whitish to grey, loose to weakly consolidated, massive to weakly stratified, centimeters to meters thick, coarse to fine ash matrix layers (diluite streamflow facies) to massive, large angular to sub-rounded siltitic blocks-rich and coarse to medium ash matrix deposits (debris flow facies). These types of lithofacies are associated to a rain-triggered lahar (De Belizal et al., 2013). The presence in some stratigraphic sections of sharp contacts, laminated layers of very fine ash, and also cm-thick sand and silt layers between the ash beds of the same deposits permit to understand that the different pulses were generated in short periods and after a long period. Structures like water pipes imply that the lahar went into the sea (Schneider, 2004), and allow the reconstruction of the paleotopographic condition during the emplacement of these deposits. This study focuses on the characterization of these types of deposits, permit to understand the kind of risk that may affect the towns located on the coast of Ecuador after VEI 4 to 6 eruptions on short time and within years.

  15. USA otsib Iraanist aktiivselt tuumainfot / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2005-01-01

    Iraan avaldas protesti USA luurelendude üle Iraani kohal. USA endine kaitseminister James Baker peab Iraani ja Põhja-Koreaga nende tuumaprogrammide hävitamiseks sõja alustamist suurimaks veaks. Kuigi Bushi meeskond rõhutab vajadust lahendada küsimus rahumeelselt, toovad Dick Cheney' ja Condoleezza Rice'i avaldused mitme USA kommentaatori arvates meelde Iraagi sõja eelse taktika

  16. Eesti on USA uus lemmik / Argo Ideon

    Index Scriptorium Estoniae

    Ideon, Argo, 1966-

    2007-01-01

    President Toomas Hendrik Ilvese visiidist Washingtoni, kohtumistest USA presidendi George W. Bushi, asepresident Dick Cheney, asevälisminister John Negroponte, kaitseminister Robert M. Gates'i, USA Kongressi esindajatekoja spiikri Nancy Pelosi ja kongresmenidega. Eestil õnnestus korraldada USA pealinnas kohtumised, mille järjekorras ootab hulk palju suuremaid riike. Vabariigi President töövisiidil Ameerika Ühendriikides 25.-26.06.2007

  17. The energy situation in the Usa

    International Nuclear Information System (INIS)

    2006-01-01

    This analyses discusses the energy supplying security, the natural gas demand increase and its consequences, the climatic change in the long-dated, the long dated perspectives of the Usa energy policy, the law on the energy and the consequences for the nuclear activity, the financial incentives in favor of the construction of new nuclear power plants in the Usa and the good nuclear energy industry situation in the Usa. (A.L.B.)

  18. USA NCAP - a glance at harmonization

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, R.M.; Park, B.T.; Beuse, N.M.; Lowrie, J.C. [National Highway Traffic Safety Administration, Washington, DC (United States); Swanson, J.L.; Rockwell, T.E. [ACE Systems Technologies, Inc. (United States)

    2001-07-01

    This paper is separated roughly into four parts. First, the authors discuss the frontal tests of the USA New Car Assessment Program (NCAP) and then consider similarities and differences in the two different types of frontal tests worldwide. Second, the focus is placed on the side crash of the USA NCAP and comparisons are made between the results of the two different types of lateral tests worldwide. Third, the paper explains the Congressional requirements to establish a child safety rating system (in the USA) by model year 2003 and looks at the approach taken by NCAPs worldwide. Finally, the growth in requests for consumer information (in the USA) is measured. (orig.)

  19. Development of a shelf margin delta due to uplift of Munkagrunnur Ridge at the margin of Faroe-Shetland Basin: a seismic sequence stratigraphic study

    DEFF Research Database (Denmark)

    Òlavsdóttir, Jana; Boldreel, Lars Ole; Andersen, Moretn S

    2010-01-01

    During the last decade several 3D digital reflection seismic datasets have been acquired in the Faroese sector of the Faroe-Shetland Basin which allow detailed seismic interpretation and mapping of parts of the area. This study presents mapping and seismic sequence stratigraphic interpretation of...

  20. Carnian bauxite horizon on the Kopitov grič near Borovnica (Slovenia – is there a »forgotten« stratigraphic gap in its footwall?

    Directory of Open Access Journals (Sweden)

    Bogomir Celarc

    2008-12-01

    Full Text Available Beds underlying the Carnian bauxite on the Kopitov gri~ (Slovenia are by the author’s opinion not Carnian (Cordevolian, but Ladinian age. The considerable stratigraphical gap is presented between Carnian clastic rocks and underlying limestones and dolomites. Bauxite is result of the weathering during the emersion.

  1. Palaeolithic/Mesolithic stratigraphic sequences at Údolí samoty and Janova zátoka rock shelters (Northern Bohemia)

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Jiří; Novák, J.; Novák, Martin; Sázelová, S.; Demek, J.; Hladilová, Š.; Peša, V.

    2013-01-01

    Roč. 43, č. 4 (2013), s. 469-488 ISSN 0342-734X R&D Projects: GA ČR GA13-08169S Institutional support: RVO:68081758 Keywords : Pleistocene/Holocene boundary * Northern Bohemia * stratigraphic sequences * rock shelters * environment Subject RIV: AC - Archeology, Anthropology, Ethnology

  2. A Ten Step Protocol and Plan for CCS Site Characterization, Based on an Analysis of the Rocky Mountain Region, USA

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, Brian; Matthews, Vince

    2013-09-15

    This report expresses a Ten-Step Protocol for CO2 Storage Site Characterization, the final outcome of an extensive Site Characterization analysis of the Rocky Mountain region, USA. These ten steps include: (1) regional assessment and data gathering; (2) identification and analysis of appropriate local sites for characterization; (3) public engagement; (4) geologic and geophysical analysis of local site(s); (5) stratigraphic well drilling and coring; (6) core analysis and interpretation with other data; (7) database assembly and static model development; (8) storage capacity assessment; (9) simulation and uncertainty assessment; (10) risk assessment. While the results detailed here are primarily germane to the Rocky Mountain region, the intent of this protocol is to be portable or generally applicable for CO2 storage site characterization.

  3. Green electricity - experiences from USA; Groen el - erfarenheter fraan USA

    Energy Technology Data Exchange (ETDEWEB)

    Graens, N

    1995-10-01

    Environmental concern has opened a market for electric power produced from renewable energy sources in USA. A number of American electric utilities have responded to the interest from the public and offered green electricity at a price somewhat above the normal rates. Most of these programs, that have existed for a few years, have succeeded quite well, giving the utilities better relations to their customers and experiences from marketing new products. The customers have been satisfied and shown enthusiasm for the new product. The present report reviews the attitudes to and drive behind green electricity from/relative to utilities, customers, environmental organizations and authorities. The programs and experiences of the utilities are described, and the prospects for green power on a deregulated market are discussed. Speculations about market responses to green power in Sweden are also made. 37 refs, 13 figs

  4. 77 FR 6587 - Startek USA, Inc. Alexandria, LA; Startek USA, Inc., Collinsville, VA; Amended Certification...

    Science.gov (United States)

    2012-02-08

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-75,089; TA-W-75,089A] Startek USA, Inc. Alexandria, LA; Startek USA, Inc., Collinsville, VA; Amended Certification Regarding Eligibility... for Worker Adjustment Assistance on January 26, 2011, applicable to workers of StarTek USA, Inc...

  5. SEDIMENTATION AND BASIN-FILL HISTORY OF THE PLIOCENE SUCCESSION EXPOSED IN THE NORTHERN SIENA-RADICOFANI BASIN (TUSCANY, ITALY: A SEQUENCE-STRATIGRAPHIC APPROACH

    Directory of Open Access Journals (Sweden)

    IVAN MARTINI

    2017-08-01

    Full Text Available Basin-margin paralic deposits are sensitive indicators of relative sea-level changes and typically show complex stratigraphic architectures that only a facies-based sequence-stratigraphic approach, supported by detailed biostratigraphic data, can help unravel, thus providing constraints for the tectono-stratigraphic reconstructions of ancient basins. This paper presents a detailed facies analysis of Pliocene strata exposed in a marginal key-area of the northern Siena-Radicofani Basin (Tuscany, Italy, which is used as a ground for a new sequence-stratigraphic scheme of the studied area. The study reveals a more complex sedimentary history than that inferred from the recent geological maps produced as part of the Regional Cartographic Project (CARG, which are based on lithostratigraphic principles. Specifically, four sequences (S1 to S4, in upward stratigraphic order have been recognised, each bounded by erosional unconformities and deposited within the Zanclean-early Gelasian time span. Each sequence typically comprises fluvial to open marine facies, with deposits of different sequences that show striking lithological similarities.The architecture and internal variability shown by the studied depositional sequences are typical of low-accommodation basin-margin settings, that shows: i a poorly-developed to missing record of the falling-stage systems tract; ii a lowstand system tract predominantly made of fluvio-deltaic deposits; iii a highstand system tract with substantial thickness variation between different sequences due to erosional processes associated with the overlying unconformity; iv a highly variable transgressive system tract, ranging from elementary to parasequential organization.

  6. Stratigraphic and structural configuration of the Navajo (Jurassic) through Ouray (Mississippian-Devonian) formations in the vicinity of Davis and Lavender Canyons, southeastern Utah

    International Nuclear Information System (INIS)

    McCleary, J.R.; Romie, J.E.

    1986-04-01

    This study developed a three-dimensional computer model of stratigraphic and structural relationships within a 3497-km 2 (1350-mi 2 ) study area centered on the proposed site for a high-level nuclear waste repository in southeastern Utah. The model consists of a sequence of internally reconciled isopach and structure contour maps horizontally registered and stored in stratigraphic order. This model can be used to display cross sections, perspective block diagrams, or fence diagrams at any orientation; estimate depth of formation contacts and thicknesses for any new stratigraphic or hydrologic boreholes; facilitate ground-water modeling studies; and evaluate the structural and stratigraphic evolution of the study area. This study also includes limited evaluations of aquifer continuity in the Elephant Canyon and Honaker Trail Formations, and of salt dissolution and flowage features as interpreted from geophysical logs. The study identified a long history of movement in the fault system in the north-central part of the study area and a major salt flowage feature in the northeastern part. It describes the Elephant Canyon Formation aquifer as laterally limited, the Honaker Trail Formation aquifer as fairly continuous over the area, and Beef Basin in the southern part of the area as a probable dissolution feature. It also concludes that the Shay-Bridger Jack-Salt Creek Graben system is apparently a vertically continuous feature between the basement and ground surface. No stratigraphic or structural discontinuities were detected in the vicinity of Davis Canyon that appear to be detrimental to the siting of a waste repository

  7. A 27 ka paleoenvironmental lake sediment record from Taro Co, central Tibetan Plateau: implications for the interplay between monsoon and the Westerlies

    Science.gov (United States)

    Wang, J.; Ma, Q.; Huang, L.; Ju, J.; Guo, Y.; Lin, X.; Li, Y.; Zhu, L.

    2017-12-01

    The climate of Tibetan Plateau (TP) is mainly influenced by the Indian Ocean Summer Monsoon (IOSM) and the Westerlies. The interaction of these two air masses is therefore a crucial scientific issue to understand how they impact the climate in this area, especially in the geological times. However, constrained by the available archives, researches on this topic are still very few in the hinterland of the TP, especially covering the Last Glacial Maximum (LGM) period. Here we present a new lake sediment record retrieved from Taro Co covering the last 27 ka to elucidate how the IOSM and the Westerlies interact and the possible mechanisms. Taro Co (486 km2, Dmax: 132m, 4565 m a.s.l., currently closed), located on the central TP, is a fresh lake with the major supply from glaciers. Two parallel piston cores as well as several gravity cores were retrieved from the deepest parts. These cores were correlated based on high resolution XRF scanning and a continuous 1069 cm-long core was finally integrated. Chronology was determined by 210Pb, 137Cs and AMS 14C measurements. Multidiscipline analyses including grain size, total organic carbon (TOC), total nitrogen, diatom, ostracod, pollen and n-alkanes were accomplished to reconstruct paleoenvironmental changes. The lake level of Taro Co was low since 27 cal ka BP indicated by very coarse materials and diatom assemblages with gradually increased temperature and salinity (TOC and carbonate getting higher). The terrestrial water input decreased continuously reflected by such elements as Si, Ti, Fe, K. It is likely that there was a sedimentation gap between 961-954cm, corresponding to 23.4 to 18.6 cal ka BP probably demonstrated Taro Co was very shallow at that period. The first prominent abrupt change of most proxies was observed at 14.7 cal ka BP showing a great lake deepening which likely indicated an enhancement of IOSM. There were several spells with abrupt changes of cold/warm stages before the Holocene and the Younger Dryas

  8. Geochemical characterization of the Jurassic Amran deposits from Sharab area (SW Yemen): Origin of organic matter, paleoenvironmental and paleoclimate conditions during deposition

    Science.gov (United States)

    Hakimi, Mohammed Hail; Abdullah, Wan Hasiah; Makeen, Yousif M.; Saeed, Shadi A.; Al-Hakame, Hitham; Al-Moliki, Tareq; Al-Sharabi, Kholah Qaid; Hatem, Baleid Ali

    2017-05-01

    Calcareous shales and black limestones of the Jurassic Amran Group, located in the Sharab area (SW Yemen), were analysed based on organic and inorganic geochemical methods. The results of this study were used to reconstruct the paleoenvironmental and paleoclimatic conditions during Jurassic time and their relevance to organic matter enrichment during deposition of the Amran calcareous shale and black limestone deposits. The analysed Amran samples have present-day TOC and Stotal content values in the range of 0.25-0.91 wt % and 0.59-4.96 wt %, respectively. The relationship between Stotal and TOC contents indicates that the Jurassic Amran deposits were deposited in a marine environment as supported by biomarker environmental indicators. Biomarker distributions also reflect that the analysed Amran deposits received high contributions of marine organic matter (e.g., algal and microbial) with minor amount of land plant source inputs. Low oxygen (reducing) conditions during deposition of the Jurassic Amran deposits are indicated from low Pr/Ph values and relatively high elemental ratios of V/Ni and V/(V + Ni). Enrichment in the pyrite grains and very high DOPT and high Fe/Al ratios further suggest reducing bottom waters. This paleo-redox (i.e., reducing) conditions contributed to preservation of organic matter during deposition of the Jurassic Amran deposits. Semi-arid to warm climatic conditions are also evidenced during deposition of the Amran sediments and consequently increased biological productivity within the photic zone of the water column during deposition. Therefore, the increased bio-productivity in combination with good preservation of organic matter identified as the major mechanisms that gave rise to organic matter enrichment. This contradicts with the low organic matter content of the present-day TOC values of less than 1%. The biomarker maturity data indicate that the analysed Amran samples are of high thermal maturity; therefore, the low present-day TOC

  9. Ichnological analysis of the Upper Miocene in the ANH-Tumaco-1-ST-P well: assessing paleoenvironmental conditions at the Tumaco Basin, in the Colombian Pacific

    Science.gov (United States)

    Giraldo-Villegas, Carlos A.; Celis, Sergio A.; Rodríguez-Tovar, Francisco J.; Pardo-Trujillo, Andrés; Vallejo-Hincapié, Diego F.; Trejos-Tamayo, Raúl A.

    2016-11-01

    Tumaco is a frontier basin located on the SW Colombian Pacific coast. It is composed of a thick siliciclastic sequence up to reach 10,000 m-thick. In recent years, the National Hydrocarbon Agency-ANH has promoted new exploration wells in order to understand the sedimentary dynamic and its relationship with petroleum systems. One of them, the ANH-Tumaco-1-ST-P well has ∼3000 m (12,000 feet). We carried out sedimentological, geochemical, and micropaleontological detailed analyses with special attention to the ichnology on a 55 m-cored interval (from 1695.3 to 1640.4 m = 5563-5382 ft) in order to assess paleoenvironmental conditions. Beds are composed of green and gray mudrocks interbedded with lithic sandstones and fine-grained tuffs. Calcareous microfossil assemblages defined by the recovery of Uvigerina carapitana, Uvigerina laviculata, Uvigerina pigmaea, Globigerina woodi, Globigerionoides obliquus, Discoaster bellus gr., Catinaster coalitus, Reticulofenestra pseudoumbilicus and Sphenolithus abies indicated a Tortonian age, between CN6/CN7 biozones. Six sedimentary facies were identified: (1, 2) massive and laminated mudrocks, (3, 4) massive and normal-graded sandstones, (5) heterolithic beds, and in some cases (6) sandstones with soft-deformation structures. These rocks were accumulated in a shallowing platform-prodelta environment with continuous volcanic influence. Ichnotaxonomic analysis, conducted for the first time in the Colombian Pacific, allowed the identification of eighteen ichnogenera: Alcyonidiopsis, Asterosoma, Chondrites, Conichnus, Cylindrichnus, Diplocraterion, Ophiomorpha, Palaeophycus, Phycosiphon, Planolites, Rhyzocorallium, Schaubcylindrichnus, Scolicia, Siphonichnus, Taeinidum, Teichichnus, Thalassinoides, and Zoophycos. The ichnological association belongs to the archetypal Cruziana ichnofacies and its "distal" expression. By integrating lithofacies and ichnological results, two segments have been distinguished: 1) the lower one (1695

  10. Stratigraphic and structural relationships between Meso-Cenozoic Lagonegro basin and coeval carbonate platforms in southern Apennines, Italy

    Science.gov (United States)

    Pescatore, Tullio; Renda, Pietro; Schiattarella, Marcello; Tramutoli, Mariano

    1999-12-01

    Stratigraphic studies and facies analysis integrated with a new geological and structural survey of the Meso-Cenozoic units outcropping in the Campania-Lucania Apennines, southern Italy, allowed us to restore the palaeogeographic pattern and the tectonic evolution of the chain during Oligo-Miocene times. The southern Apennines are a N150°-striking and NE-verging fold-and-thrust belt mainly derived from the deformation of the African-Apulian passive margin. Four wide belts with different features have been recognized in the chain area. From east to west the following units outcrop: (a) successions characterized by basinal to marginal facies, ranging in age from Cretaceous to Miocene, tectonically lying on Plio-Pleistocene foredeep deposits; (b) successions characterized by shallow-water, basinal and shelf-margin facies, ranging in age from middle Triassic to Miocene ('Lagonegro units'), overthrust on the previous ones; (c) Triassic to Miocene carbonate platform successions ('Apenninic platform units'), overthrust on the Lagonegro units; (d) Jurassic-Cretaceous to Miocene deep-water successions (ophiolite-bearing or 'internal' units and associated siliciclastic wedges), outcropping along the Tyrrhenian belt and the Calabria-Lucania boundary, overthrust on the Apenninic platform units. All these units tectonically lie on the buried Apulian platform which is covered, at least in the eastern sector of the chain, by Pliocene to Pleistocene foredeep deposits. Stratigraphic patterns of the Cretaceous to lower Miocene Lagonegro successions are coherent with the platform margin ones. Calcareous clastics of the Lagonegro basin are in fact supplied by an adjacent western platform, as inferred by several sedimentological evidences (slump and palaeocurrent directions and decreasing grain size towards the depocentre of the basin). Tectonic relationships among the different units of the chain — with particular emphasis on the Lagonegro and Apenninic platform units of the

  11. 3D stratigraphic modeling of the Congo turbidite system since 210 ka: an investigation of factors controlling sedimentation

    Science.gov (United States)

    Laurent, Dimitri; Picot, Marie; Marsset, Tania; Droz, Laurence; Rabineau, Marina; Granjeon, Didier; Molliex, Stéphane

    2017-04-01

    The geometry and internal functioning of turbidite systems are relatively well-constrained today. However, the respective role of autogenic (topographic compensation, dynamics of turbidity currents…) and allogenic factors (tectonics, sea-level, climate) governing their architectural evolution is still under debate. The geometry of the Quaternary Congo Fan is characterized by successive sedimentary prograding/retrograding cycles bounded by upfan avulsions, reflecting a periodic control of sedimentation (Picot et al., 2016). Multi-proxy studies revealed a strong interplay between autogenic control and climate forcing as evidenced by changes in fluvial sediment supplies consistent with arid and humid periods in the Congo River Basin. In the light of these results, the aim of this study is to investigate the relative impact of internal and external forcing factors controlling, both in time and space, the formation and evolution of depocenters of the Congo Deep-Sea Fan since 210 ka. This work represents the first attempt to model in 3D the stratigraphic architecture of the Congo turbidite system using DionisosFlow (IFP-EN), a diffusion process-based software. It allows the simulation of sediment transport and the 3D geometry reproduction of sedimentary units based on physical processes such as sea level changes, tectonics, sediment supply and transport. According to the modeling results, the role of topographic compensation in the deep-sea fan geometry is secondary compared to climate changes in the drainage basin. It appears that a periodic variation of sediment discharge and water flow is necessary to simulate the timing and volume of prograding/retrograding sedimentary cycles and more particularly the upfan avulsion events. The best-fit simulations show that the overriding factor for such changes corresponds to the expansion of the vegetation cover in the catchment basin associated to the Milankovitch cycle of precession which controlled the West African Monsoon

  12. USA tankid jõudsid Tapale

    Index Scriptorium Estoniae

    2017-01-01

    Tapale saabus poolsada USA sõjamasinat, nende seas neli tanki Abrams M1A2 ja 15 jalaväe lahingumasinat Bradley. Tehnikat hakkab kasutama USA maaväe 4. jalaväediviisi 68. soomusrügemendi esimese pataljoni C-kompanii

  13. USA allveelaev uputas kalalaeva / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2001-01-01

    Hawaii lähistel õppustel kiiret pinnaletõusu harjutanud USA allveelaev USS Greeneville põrkas kokku Jaapani õppelaevaga Ehime Maru, õnnetuse tagajärjel hukkus tõenäoliselt 9 jaapanlast. Skeem: Õnnetused USA allveelaevadega

  14. Poola ootab USA maaväelasi

    Index Scriptorium Estoniae

    2014-01-01

    Poola kaitseministri Tomasz Siemoniaki sõnul saadab USA Poolasse maavägesid, et laeindada NATO kohalolekut ajal, mil pingeline olukord Ukrainas kestab, kirjutas Washington Post. Siemoniak ütles lehele, et sõjalised planeerijad juba töötavad vastava kava üksikasjade kallal. Ta lisas, et tõenäoliselt saadetakse USA sõdureid ka Baltimaadesse

  15. Krossil on probleeme USA viisaga? / Raimo Poom

    Index Scriptorium Estoniae

    Poom, Raimo

    2011-01-01

    Eesti Päevaleht esitas USA Eesti-saatkonnale järelepärimise seoses sellega, et Eerik-Niiles Krossi USA-viisa on tühistatud. Saatkonna pressi- ja kultuuriatašee James Landi vastusest. Eerik-Niiles Krossi kommentaare

  16. Bulgaaria valitsus tahab USA raketikilpi / Mihkel Niglas

    Index Scriptorium Estoniae

    Niglas, Mihkel

    2007-01-01

    Bulgaarias küsiti USA presidendilt George W. Bushilt, miks Poolasse ja Tšehhi kavandatav raketikilp ei hakka katma Bulgaariat. USA paigutab septembris Bulgaaria sõjabaasi üle 3000 sõduri. George W. Bush toetab Bulgaaria nõudmist Liibüale vabastada Bulgaaria meditsiiniõed

  17. Etteheide: USA okupeerib Haitit / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2010-01-01

    Prantsusmaa ja Brasiilia on esitanud protesti, sest USA sõjalennukitele on antud eelisõigus Haiti pealinna Port-au-Prince'i lennujaama kasutamisel. Paljude kommentaatorite hinnangul on Prantsusmaa püüdnud haarata prominentset rolli Haiti abistamisel, kuid USA on tegutsenud kiiremini ja jõulisemalt. Kaart

  18. USA raport hoiatab tuumaterroristide eest / Karin Volmer

    Index Scriptorium Estoniae

    Volmer, Karin

    2007-01-01

    USA-s tegutseva tuumaterrori vastase organisatsiooni Nuclear Threat Initiative (NTI) raport kinnitab maailma edusamme tuumamaterjali turvalisuses, kuid on ka palju ohuallikaid. Analüütikud kahtlevad Venemaa ja Pakistani armee usaldusväärsuses tuumamaterjali hoidmisel. Lisa: Tuumaterrori raport

  19. USA's litterære superstjerne

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2010-01-01

    Jonathan Franzen er den mest omtalte forfatter i USA lige nu og ombejlet af alle fra Time Magazine til Oprah Winfrey. Hvad er det, han kan, manden bag ”Freedom”?......Jonathan Franzen er den mest omtalte forfatter i USA lige nu og ombejlet af alle fra Time Magazine til Oprah Winfrey. Hvad er det, han kan, manden bag ”Freedom”?...

  20. Stratigraphic evolution of the Late Jurassic Hanifa Formation along the Tuwaiq Escarpment, Saudi Arabia: Evidence for a carbonate ramp system

    Science.gov (United States)

    Fallatah, Mohammed I.; Kerans, Charles

    2018-01-01

    A sequence stratigraphic framework of the Late Jurassic (Oxfordian) Hanifa Formation at its exposure in Central Arabia is presented for the first time. This study offers the first high-resolution stratigraphic framework of the Hanifa along the Tuwaiq Escarpment by measuring 15 sections ( 770 m total thickness) over an oblique-to-dip distance of 260 km and collecting 295 samples for petrographic analysis. On the basis of these data, the Hanifa Formation can be subdivided into eight facies; 1) tabular cross-bedded quartz-peloidal-skeletal grainstone, 2) cross-bedded skeletal-peloidal grainstone, 3) bioturbated foraminiferal wackestone/mud-dominated packstone, 4) oncolitic rudstone, 5) stromatoporoid-coral biostrome/bioherm, 6) peloidal/composite-grain grain-dominated packstone/grainstone, 7) bioturbated spiculitic wackestone/mud-dominated packstone, and 8) thinly-bedded argillaceous mudstone/wackestone. The vertical and lateral distributions of these facies along the exposure define their sequence setting using the principals of sequence stratigraphy. By recognizing erosional surfaces, facies offset, and changes in facies proportions, five third-order sequences, with an average duration of 1.1 Myr, are interpreted for the Hanifa Formation. The correlation of the sequences across the study area shows that only four sequences are preserved in the north where shallow-water deposits are well-developed. Facies trends within these sequences are further illustrated in depositional models representing the highstand systems tracts (HST) and the transgressive systems tracts (TST) of the Hanifa Formation. These proposed models represent depositional settings of a carbonate ramp with normal open-marine conditions. The HST depositional model is characterized by a high-energy shoreline and depicts the presence of an offshore, structurally controlled skeletal-peloidal shoal body described here for the first time at the Hanifa exposure in the Hozwa area. This work provides a

  1. The ``Problem of the quaternary'' and the taxonomic rank of the late cenozoic in the international stratigraphic scale

    Science.gov (United States)

    Zubakov, V. A.

    2011-02-01

    An international scientific conflict has arisen around the International Stratigraphic Scale, the main document that regulates the rules of reading of geological records and, hence, concerns all Earth sciences. The matter of debate is the geological time scale of 2004, developed by the International Commission on Stratigraphy, where the Quaternary system was abandoned. This ICS decision triggered a protest among Quaternary geologists, members of INQUA, and became the subject of much controversy. This article provides a comprehensive analysis of the Quaternary problem and proposes a reasonable scientific solution that may be appropriate for both parties. The subject of Late Cenozoic geology is discussed: glaciations, human evolution, and recent deposits. In contrast to Charles Lyell's definition of the Plio-Pleistocene according to the percentage of modern mollusk species, it is defined here as a blanket formation, which is correlative to the topography and consists of mapped stratogens hosting fossils of modern biogeocenoses. Features of the description of the Plio-Pleistocene in terms of gravitational orbital tuning are considered. Four paleogeographic phases of modern environment evolution are recognized and ranked as stages: (1) The Messinian evolutionary explosion involved the appearance of many biogeocenoses and the bipedal walking of our extinct ancestors armed with sticks. It was a consequence of the Early Greenland (7.6 Ma BP) and Patagonian (6.7 Ma BP) hyperglaciations. (2) The Zanclean age is marked by climatic and hydrological but not evolutionary boundaries. (3) The appearance of the Villafranchian animal assemblage and Australopithecus, who used stones as weapon: 4.0-3.6 Ma BP. Orogeny and isolation of the Arctic Ocean changed the global climate dramatically. (4) The sexual revolution became the third evolutionary jump: the appearance of the first woman, "Eve", and the genus Homo with her: 1.9 Ma BP. According to the current view, the Plio

  2. Ideaalne torm USA majanduses / Ken Goldstein ; interv. Neeme Raud

    Index Scriptorium Estoniae

    Goldstein, Ken

    2008-01-01

    USA majandusuuringute organisatsiooni The Conference Board analüütik USA majanduse olukorrast, mõjust maailmamajandusele, arenguvõimalustest ning uue presidendi vajalikest sammudest majanduses. Lisa: Enamuse arvates on USA valel teel

  3. High resolution spectroscopic mapping imaging applied in situ to multilayer structures for stratigraphic identification of painted art objects

    Science.gov (United States)

    Karagiannis, Georgios Th.

    2016-04-01

    The development of non-destructive techniques is a reality in the field of conservation science. These techniques are usually not so accurate, as the analytical micro-sampling techniques, however, the proper development of soft-computing techniques can improve their accuracy. In this work, we propose a real-time fast acquisition spectroscopic mapping imaging system that operates from the ultraviolet to mid infrared (UV/Vis/nIR/mIR) area of the electromagnetic spectrum and it is supported by a set of soft-computing methods to identify the materials that exist in a stratigraphic structure of paint layers. Particularly, the system acquires spectra in diffuse-reflectance mode, scanning in a Region-Of-Interest (ROI), and having wavelength range from 200 up to 5000 nm. Also, a fuzzy c-means clustering algorithm, i.e., the particular soft-computing algorithm, produces the mapping images. The evaluation of the method was tested on a byzantine painted icon.

  4. New insights into the stratigraphic, paleogeographic and tectonic evolution and petroleum potential of Kerkennah Islands, Eastern Tunisia

    Science.gov (United States)

    Elfessi, Maroua

    2017-01-01

    This work presents general insights into the stratigraphic and paleogeographic evolution as well as the structural architecture and the petroleum potential of Kerkennah Islands, located in the Eastern Tunisia Foreland, from Cenomanian to Pliocene times. Available data from twenty wells mostly drilled in Cercina and Chergui fields are used to establish three lithostratigraphic correlations as well as isopach and isobath maps in order to point out thickness and depth variations of different geological formations present within our study area; in addition to a synthetic log and isoporosity map of the main carbonate reservoir (the nummulites enriched Reineche Member). The integrated geological study reveals relatively condensed but generally continuous sedimentation and a rugged substrate with horsts, grabens and tilted blocks due to the initiation and the individualization of Kerkennah arch throughout the studied geological times. Furthermore, a relationship was highlighted between the evolution of our study zone and those of Sirt basin, Western Mediterranean Sea and Pelagian troughs; this relationship is due to the outstanding location of Kerkennah Islands. The main Bou Dabbous source rock is thicker and more mature within the central-east of the Gulf of Gabes indicating therefore the southeast charge of Reineche reservoir which shows NW-SE trending tilted block system surrounded by normal faults representing the hydrocarbon migration pathways. Besides, the thick Oligo-Miocene formations deposited during the collapse of the Pelagian block caused the maturation of the Ypresian source rock, while the Pliocene unconformity allowed basin inversion and hydrocarbon migration.

  5. Inversion aided systems for stratigraphic models; Systemes d'aide a l'inversion des modeles stratigraphiques

    Energy Technology Data Exchange (ETDEWEB)

    Dobranszky, G.

    2005-12-15

    Stratigraphic modeling aims at rebuilding the history of the sedimentary basins by simulating the processes of erosion, transport and deposit of sediments using physical models. The objective is to determine the location of the bed-rocks likely to contain the organic matter, the location of the porous rocks that could trap the hydrocarbons during their migration and the location of the impermeable rocks likely to seal the reservoir. The model considered within this thesis is based on a multi-lithological diffusive transport model and applies to large scales of time and space. Due to the complexity of the phenomena and scales considered, none of the model parameters is directly measurable. Therefore it is essential to inverse them. The standard approach, which consists in inverting all the parameters by minimizing a cost function using a gradient method, proved very sensitive to the choice of the parameterization, to the weights given to the various terms of the cost function (hearing on data of very diverse nature) and to the numerical noise. These observations led us to give up this method and to carry out the in-version step by step by decoupling the parameters. This decoupling is not obtained by fixing the parameters but by making several assumptions on the model resulting in a range of reduced but relevant models. In this thesis, we show how these models enable us to inverse all the parameters in a robust and interactive way. (author)

  6. Hydrodynamism, crude oil distribution and geochemistry of the stratigraphic column in a transect of the Eastern Venezuelan Basin

    Energy Technology Data Exchange (ETDEWEB)

    Gallango, O.; Escandon, M.; Alberdi, M. (Intevep, S.A. Caracas (Venezuela)); Parnaud, F.; Pascual, J.C. (Beicip, Rueil Malmaison (France))

    1992-01-01

    The hydrocarbon accumulation history in a transect of the Eastern Venezuelan Basin is closely related to the generation and migration process as a consequence of the stratigraphic, structural and tectonic evolution of the basin during the Cretaceous and Cenozoic times. Thermal maturity assessment based on kinetic parameters using the appropriate software indicates that the generation of oil from the marine facies of the Querecual and San Antonio source rocks in the northern part of the basin took place during early Paleocene to early Miocene times prior to the start of thrusting, while the second and third phase occurred during middle Miocene to recent times in zones beneath the principal thrust in the Maturing area. The third phase of oil generation is associated with the latter thrusts which are out of sequence. Taking into consideration the development of the oil and gas kitchen through time, the hydrodynamism, the characteristics and distribution of the hydrocarbons, the migration of oil and gas have been outlined. The major differences observed among the oils, are due to maturity and post-accumulation processes such as oil mixing and biodegradation. A wide range of thermal maturity was observed in the oils, which is mainly due to the thermal stress experienced by the source rock. Association of light crudes with meteoric waters have been observed, as well as heavy to extra-heavy crudes with connate waters at greater depth. These unusual associations of crudes and formation waters are related to the hydrodynamical regime in the basin.

  7. Stratigraphic, Structural and Petrophysical Evaluation of borehole images obtained in oil based mud environment from Clastics of Niger Delta

    International Nuclear Information System (INIS)

    Ogunyemi, T.

    2003-01-01

    With the advent of oil-base and synthetic muds, drilling risks are substantially reduced and efficiency dramatically increased, but the benefits of borehole imaging devices were lost as it presents a 'brick-wall' and difficult environment that precludes the use of conventional water- base mud microresistivity imaging devices. The introduction of Oil Base Imager tools offers a solution to the situation and even brings additional values. Borehole images integrated with high resolution Magnetic Resonnance data and other open hole logs has been evaluated for stratigraphic, structural and petrophysical applications as well as computing high-resolution sand count. Examples will be discussed in this paper. The sequence studied is clastics with intercalated sand/shale sequences typical of Niger Delta. The use of oil based mud images and open-hole log data helped to further classify the sequence into depositional environments. Generally speaking high-resolution image data presents opportunity for accurate results especially in intercalated sand/shale sequence compare to standard open hole logs. Individual pad resistivity response offer a very high resolution measurement that was used to drive the net pay sand count analysis. This approach has been proven to be helpful in completion decision, providing accurate reservoir parameters for well/field economics and development

  8. On the question of stratigraphic detail Konkian deposits Borysthenian Bay (southern Ukraine on the fauna of molluscs

    Directory of Open Access Journals (Sweden)

    Staryn D.A.

    2013-09-01

    Full Text Available The results of study marine bivalve and gastropod from konkian-sarmatian deposits of the Southern Ukraine are gave. Their lateral and vertical distribution is studied. Local stratigraphic schemes for the Northern Black Sea region, Plane Crimea and Kerch peninsula are built. It is confirmed the Konkian regional stage divisible into three parts: the Kartvel (Ervilia and Pholada, Sartagan and Veselyanka layers. The lower part (Kartvel layers is characterized by monomorphic fauna of Ervilia and / or Pholada; other shellfish are virtually absent. The middle part (Sartagan layers contains polihalin shellfish such as Turritella, Chlamys et al., but their findings are rare. In this common transit fauna, which can cause significant difficulties in the stratification of the regional stage. The upper part (Veselyanka layers by the absence of (or single polihalin elements and extensive development of some types of Cardiidae. The individual seams with Ervilia and Barnea met throughout the section tram and fauna differ from the Kartvel layers joint finding other taxa Konkian shellfish and usually less power. The possibility of fractional stratification Sarmatian regional stage in different structural-facial areas of the Southern Ukraine. Change shellfish communities on the border of the lower and middle Sarmatian occurs gradually in clay sediments and more clearly in the coastal sandy and sandy-clay rocks. Separation of Vasilyevsky and Dnepropetrovsk layers of middle Sarmatian malacofauna problematic in areas of strong recrystallized limestone. For the detail section is necessary to study rocks in thin sections.

  9. Proposed stratigraphic nomenclature and macroscopic identification of lithostratigraphic units of the Paintbrush Group exposed at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Buesch, D.C.; Spengler, R.W.; Moyer, T.C.; Geslin, J.K.

    1996-09-01

    This paper describes the formations of the Paintbrush Group exposed at Yucca Mountain, Nevada, presents a detailed stratigraphic nomenclature for the Tiva Canyon and Topopah spring Tuffs, and discusses the criteria that define lithostratigraphic units. The Tiva Canyon and Topopah Spring Tuffs are divided into zones, subzones, and intervals on the basis of macroscopic features observed in surface exposures and borehole samples. Primary divisions reflect depositional and compositional zoning that is expressed by variations in crystal content, phenocryst assemblage, pumice content and composition, and lithic content. Secondary divisions define welding and crystlalization zones, depositional features, or fracture characteristics. Both formations are divided into crystal-rich and crystal-poor members that have an identical sequency of zones, although subzone designations vary slightly between the two units. The identified lithostratigraphic divisions can be used to approximate thermal-mechanical and hydrogeologic boundaries in the field. Linking these three systems of nomenclature provides a framework within which to correlate these properties through regions of sparse data.

  10. Diversity and Distribution of Archaea Community along a Stratigraphic Permafrost Profile from Qinghai-Tibetan Plateau, China

    Directory of Open Access Journals (Sweden)

    Shiping Wei

    2014-01-01

    Full Text Available Accompanying the thawing permafrost expected to result from the climate change, microbial decomposition of the massive amounts of frozen organic carbon stored in permafrost is a potential emission source of greenhouse gases, possibly leading to positive feedbacks to the greenhouse effect. In this study, the community composition of archaea in stratigraphic soils from an alpine permafrost of Qinghai-Tibetan Plateau was investigated. Phylogenic analysis of 16S rRNA sequences revealed that the community was predominantly constituted by Crenarchaeota and Euryarchaeota. The active layer contained a proportion of Crenarchaeota at 51.2%, with the proportion of Euryarchaeota at 48.8%, whereas the permafrost contained 41.2% Crenarchaeota and 58.8% Euryarchaeota, based on 16S rRNA gene sequence analysis. OTU1 and OTU11, affiliated to Group 1.3b/MCG-A within Crenarchaeota and the unclassified group within Euryarchaeota, respectively, were widely distributed in all sediment layers. However, OTU5 affiliated to Group 1.3b/MCG-A was primarily distributed in the active layers. Sequence analysis of the DGGE bands from the 16S rRNAs of methanogenic archaea showed that the majority of methanogens belonged to Methanosarcinales and Methanomicrobiales affiliated to Euryarchaeota and the uncultured ZC-I cluster affiliated to Methanosarcinales distributed in all the depths along the permafrost profile, which indicated a dominant group of methanogens occurring in the cold ecosystems.

  11. Earlier (late Pliocene) first appearance of the Caribbean reef-building coral Acropora palmata: Stratigraphic and evolutionary implications

    Science.gov (United States)

    McNeill, Donald F.; Budd, Ann F.; Borne, Pamela F.

    1997-10-01

    An integrated stratigraphic study of reefal deposits on the Caribbean side of the Isthmus of Panama (Limon, Costa Rica) has discovered a significantly earlier first appearance of the major reef-building coral Acropora palmata. A. palmata is here reported from the early late Pliocene, constrained in age to within the Gauss chron (ca. 3.6 2.6 Ma). This coral was previously thought to have originated in the earliest Pleistocene and has subsequently been used as a Quaternary marker throughout the Caribbean and the Bahamas. An earlier appearance in the southern Caribbean implies a diachronous first appearance datum relative to the northern Caribbean. This older age also places A. palmata well within the transition phase of a Pliocene (4 1 Ma) faunal turnover that was marked by widespread extinction and origination of Caribbean coral species. An early late Pliocene origination is coincident with formation of the Isthmus, climate reorganization, and frequent sea-level changes associated with onset of Northern Hemisphere glaciations. The rapid growth and accumulation rates that characterize A. palmata may therefore be adaptive to these fluctuating environmental conditions, enabling its success during the subsequent Pleistocene glacial cycles.

  12. Interpretation of wireline geophysical logs. ERDA No. 9 stratigraphic test borehole, DOE WIPP Site, Eddy County, New Mexico

    International Nuclear Information System (INIS)

    Griswold, G.B.; McWhirter, V.C.

    1981-02-01

    A stratigraphic core hole known as ERDA No. 9 was drilled at the approximate center of the Waste Isolation Pilot Plant (WIPP) site located east of Carlsbad, New Mexico. The hole was continuously cored from 1090 to 2887 feet, the total depth of the hole. A suite of 20 wireline geophysical logs were made under open hole conditions over the cored interval. Recording in the field was by analog strip charts. The records were subsequently digitized at 0.5 foot intervals with the data placed on magnetic tape. A simple computer program was devised to interpret rock type and calculate elastic properties based on the digital data. All of the data is available in convenient digital form, and additional computer-assisted analysis is now possible to describe the detailed stratigraphy of the evaporites penetrated in ERDA No. 9. The analysis performed thus far is in excellent agreement with physical examination of the core. The main advantage of correlating the wireline geophysical logs with core is to provide a better basis for using wireline logs to describe rock conditions either in future holes drilled by the simpler rotary method or where core has been lost in cored holes

  13. Microfacies models and sequence stratigraphic architecture of the Oligocene–Miocene Qom Formation, south of Qom City, Iran

    Directory of Open Access Journals (Sweden)

    Mahnaz Amirshahkarami

    2015-07-01

    Full Text Available The Oligocene–Miocene Qom Formation has different depositional models in the Central Iran, Sanandaj–Sirjan and Urumieh-Dokhtar magmatic arc provinces in Iran. The Kahak section of the Qom Formation in the Urumieh-Dokhtar magmatic arc has been studied, in order to determinate its microfacies, depositional model and sequence stratigraphy. The textural analysis and faunal assemblages reveal ten microfacies. These microfacies are indicative of five depositional settings of open marine, patch reef, lagoon, tidal flat and beach of the inner and middle ramp. On the basis of the vertical succession architecture of depositional system tracts, four third-order sequences have been recognized in the Oligocene–Miocene Kahak succession of Qom Formation. Based on the correlation charts, the transgression of the Qom Sea started from the southeast and continued gradually towards the north. This resulted in widespread northward development of the lagoon paleoenvironment in the Aquitanian-Burdigalian stages. Also, the sequence stratigraphic model of the Oligocene–Miocene Qom Formation has an architecture similar to those that have developed from Oligocene–Miocene global sea level changes.

  14. Geomorphology and till architecture of terrestrial palaeo-ice streams of the southwest Laurentide Ice Sheet: A borehole stratigraphic approach

    Science.gov (United States)

    Norris, Sophie L.; Evans, David J. A.; Cofaigh, Colm Ó.

    2018-04-01

    A multidimensional study, utilising geomorphological mapping and the analysis of regional borehole stratigraphy, is employed to elucidate the regional till architecture of terrestrial palaeo-ice streams relating to the Late Wisconsinan southwest Laurentide Ice Sheet. Detailed mapping over a 57,400 km2 area of southwestern Saskatchewan confirms previous reconstructions of a former southerly flowing ice stream, demarcated by a 800 km long corridor of megaflutes and mega-scale glacial lineations (Ice Stream 1) and cross cut by three, formerly southeast flowing ice streams (Ice Streams 2A, B and C). Analysis of the lithologic and geophysical characteristics of 197 borehole samples within these corridors reveals 17 stratigraphic units comprising multiple tills and associated stratified sediments overlying preglacial deposits, the till thicknesses varying with both topography and distance down corridor. Reconciling this regional till architecture with the surficial geomorphology reveals that surficial units are spatially consistent with a dynamic switch in flow direction, recorded by the cross cutting corridors of Ice Streams 1, 2A, B and C. The general thickening of tills towards lobate ice stream margins is consistent with subglacial deformation theory and variations in this pattern on a more localised scale are attributed to influences of subglacial topography including thickening at buried valley margins, thinning over uplands and thickening in overridden ice-marginal landforms.

  15. Proposed stratigraphic nomenclature and macroscopic identification of lithostratigraphic units of the Paintbrush Group exposed at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Buesch, D.C.; Spengler, R.W.; Moyer, T.C.; Geslin, J.K.

    1996-01-01

    This paper describes the formations of the Paintbrush Group exposed at Yucca Mountain, Nevada, presents a detailed stratigraphic nomenclature for the Tiva Canyon and Topopah spring Tuffs, and discusses the criteria that define lithostratigraphic units. The Tiva Canyon and Topopah Spring Tuffs are divided into zones, subzones, and intervals on the basis of macroscopic features observed in surface exposures and borehole samples. Primary divisions reflect depositional and compositional zoning that is expressed by variations in crystal content, phenocryst assemblage, pumice content and composition, and lithic content. Secondary divisions define welding and crystlalization zones, depositional features, or fracture characteristics. Both formations are divided into crystal-rich and crystal-poor members that have an identical sequency of zones, although subzone designations vary slightly between the two units. The identified lithostratigraphic divisions can be used to approximate thermal-mechanical and hydrogeologic boundaries in the field. Linking these three systems of nomenclature provides a framework within which to correlate these properties through regions of sparse data

  16. paleoenvironmental settings and assemblage changes

    African Journals Online (AJOL)

    Kasanzu

    shallow borehole drilled in the southern coastal basin of Tanzania with the aim of characterizing foraminifera and palynomorphs assemblage changes aiming at reconstructing ..... decline in temperature at EOT which caused the extinction of ...

  17. Atomic power development in USA

    International Nuclear Information System (INIS)

    Wiggin, E.

    1976-01-01

    Many problems concerning the atomic power development in USA are investigated and discussed. (Introduction of fast breeder reactors is not considered in this paper). The first problem is the raising of capital for plant construction. The second problem is the supply of uranium. Estimated amount of yellow cake and its price are presented and compared with estimated demands. It is concluded that 3.5x10 6 tons of yellow coke is sufficient for generating 7x10 8 KW of electric power up to about 2000. The third problem is the enrichment service. Balance of supply and demand is discussed together with the projected extension of existing plants and the construction of new plants. The completion of nuclear fuel cycle is discussed as the fourth problem. According to the author's opinion, technological problems of reprocessing, storing, waste disposal, and the utilization of mixed oxide fuel are not difficult to solve. Definite judgement of NRC and ERDA is strongly required. The last problem discussed in this paper is the public acceptance. The movements of anti-nuclear groups and the opinion of general public are analyzed and the role of AIF in presenting paper informations is discussed. (Aoki, K.)

  18. Obchodní politika USA

    OpenAIRE

    Vaculíková, Hana

    2008-01-01

    Práce se zabývá nástroji a cíli obchodní politiky USA - aktivitami, které liberalizují celosvětový obchod. V první části je popsáno postavení Spojených států amerických v mnohostranném obchodním systému a vývoj zahraničního obchodu v posledních letech. Druhá kapitola je zaměřena na autonomní a smluvní nástroje obchodní politiky ovlivňující import, export a domácí výrobu. O obchodních dohodách uzavřených na mnohostranné, regionální a dvoustranné úrovni pojednává třetí kapitola....

  19. Licensing reform in the USA

    International Nuclear Information System (INIS)

    1991-01-01

    The licensing process for nuclear power plants in the USA is currently in two distinct stages: the issuance of a construction permit followed later by the issuance of an operation license. The ''two-step'' process has come under heavy criticism from the U.S. nuclear industry on the grounds that it causes uncertainty and delays and therefore inhibits new commitments to nuclear power plants. In 1989 the NRC published new regulations for the licensing of nuclear power plants which provide for the issuance of early site permits, safety certifications of standard designs, and combined construction permits and operating licences. The new rule was challenged by intervenors representing antinuclear groups who filed a legal challenge seeking to have the rule set aside on the grounds that it violates the Atomic Energy Act which they allege makes two-step licensing mandatory. In November 1990 the US Court of Appeals upheld the NRC's authority to issue combined licenses. An appeal for a rehearing has been filed. The paper analyses the events and the possible consequences of an adverse court decision. It reviews the options open to the NRC and industry if the court decision is upheld. The possibility of congressional action to amend the Atomic Energy Act is discussed. (author)

  20. Small mammal taxonomy, taphonomy, and the paleoenvironmental record during the Middle and Upper Paleolithic at Geißenklösterle Cave (Ach Valley, southwestern Germany)

    Science.gov (United States)

    Rhodes, Sara E.; Ziegler, Reinhard; Starkovich, Britt M.; Conard, Nicholas J.

    2018-04-01

    the proportion of cold tundra adapted species, suggesting that the tundra expanded leading up to the Neanderthal depopulation, but no period of drastic climatic change is recognizable. The Aurignacian was significantly colder and drier than the preceding period, with cold tundra expansion reaching its apex (for the time period studied). Based on these results the Swabian landscape first encountered by Aurignacian groups was significantly less hospitable than that known to the earlier Middle Paleolithic populations. These results correlate well with past paleoenvironmental reconstructions based on sedimentary, botanical, and faunal assemblages. There is no evidence in the small mammal record that climatic pressure drove Neanderthals from the Ach Valley, instead it seems likely they enjoyed a more temperate environment than later Aurignacian groups. Ongoing work focused on greater resolution of these climatic oscillations at similarly well-dated Swabian sites will shed further light on the timing and speed of this climatic shift and the response of the biological communities affected, including early human groups.

  1. Aeolian sedimentary processes at the Bagnold Dunes, Mars: Implications for modern dune dynamics and sedimentary structures in the aeolian stratigraphic record of Mars

    Science.gov (United States)

    Ewing, Ryan C.; Bridges, Nathan T.; Sullivan, Rob; Lapotre, Mathieu G. A.; Fischer, Woodward W.; Lamb, Mike P.; Rubin, David M.; Lewis, Kevin W.; Gupta, Sanjeev

    2016-04-01

    Wind-blown sand dunes are ubiquitous on the surface of Mars and are a recognized component of the martian stratigraphic record. Our current knowledge of the aeolian sedimentary processes that determine dune morphology, drive dune dynamics, and create aeolian cross-stratification are based upon orbital studies of ripple and dune morphodynamics, rover observations of stratification on Mars, Earth analogs, and experimental and theoretical studies of sand movement under Martian conditions. In-situ observations of sand dunes (informally called the Bagnold Dunes) by Curiosity Rover in Gale Crater, Mars provide the first opportunity to make observations of dunes from the grain-to-dune scale thereby filling the gap in knowledge between theory and orbital observations and refining our understanding of the martian aeolian stratigraphic record. We use the suite of cameras on Curiosity, including Navigation Camera (Navcam), Mast Camera (Mastcam) and Mars Hand Lens Imager (MAHLI), to make observations of the Bagnold Dunes. Measurements of sedimentary structures are made where stereo images are available. Observations indicate that structures generated by gravity-driven processes on the dune lee slopes, such as grainflow and grainfall, are similar to the suite of aeolian sedimentary structures observed on Earth and should be present and recognizable in Mars' aeolian stratigraphic record. Structures formed by traction-driven processes deviate significantly from those found on Earth. The dune hosts centimeter-scale wind ripples and large, meter-scale ripples, which are not found on Earth. The large ripples migrate across the depositional, lee slopes of the dune, which implies that these structures should be present in Mars' stratigraphic record and may appear similar to compound-dune stratification.The Mars Science Laboratory Curiosity Rover Team is acknowledged for their support of this work.

  2. Discovery of Jurassic ammonite-bearing series in Jebel Bou Hedma (South-Central Tunisian Atlas): Implications for stratigraphic correlations and paleogeographic reconstruction

    Science.gov (United States)

    Bahrouni, Néjib; Houla, Yassine; Soussi, Mohamed; Boughdiri, Mabrouk; Ali, Walid Ben; Nasri, Ahmed; Bouaziz, Samir

    2016-01-01

    Recent geological mapping undertaken in the Southern-Central Atlas of Tunisia led to the discovery of Jurassic ammonite-bearing series in the Jebel Bou Hedma E-W anticline structure. These series represent the Southernmost Jurassic rocks ever documented in the outcrops of the Tunisian Atlas. These series which outcrop in a transitional zone between the Southern Tunisian Atlas and the Chott basin offer a valuable benchmark for new stratigraphic correlation with the well-known Jurassic series of the North-South Axis of Central Tunisia and also with the Jurassic subsurface successions transected by petroleum wells in the study area. The preliminary investigations allowed the identification, within the most complete section outcropping in the center of the structure, of numerous useful biochronological and sedimentological markers helping in the establishment of an updated Jurassic stratigraphic framework chart of South-Western Tunisia. Additionally, the Late Jurassic succession documents syn-sedimentary features such as slumping, erosion and reworking of sediments and ammonite faunas that can be considered as strong witnesses of an important geodynamic event around the Jurassic-Cretaceous boundary. These stratigraphic and geodynamic new data make of the Jurassic of Jebel Bou Hedma a key succession for stratigraphic correlation attempt between Atlas Tunisian series and those currently buried in the Chott basin or outcropping in the Saharan platform. Furthermore, the several rich-ammonite identified horizons within the Middle and Upper Jurassic series constitute reliable time lines that can be useful for both paleogeographic and geodynamic reconstructions of this part of the North African Tethyan margin but also in the refinement of the potential migration routes for ammonite populations from the Maghrebian Southern Tethys to Arabia.

  3. The Application of Seismic Attributes and Wheeler Transformations for the Geomorphological Interpretation of Stratigraphic Surfaces: A Case Study of the F3 Block, Dutch Offshore Sector, North Sea

    OpenAIRE

    Mohammad Afifi Ishak; Md. Aminul Islam; Mohamed Ragab Shalaby; Nurul Hasan

    2018-01-01

    This study was carried out in the Pliocene interval of the southern North Sea F3 Block in the Netherlands. This research paper demonstrates how an integrated interpretation of geological information using seismic attributes, sequence stratigraphic interpretation and Wheeler transformation methods allow for the accurate interpretation of the depositional environment of a basin, as well as locating seismic geomorphological features. The methodology adopted here is to generate a 3D dip-steered H...

  4. Geostatistical and stratigraphic analysis of deltaic reservoirs from the Reconcavo Basin, Brazil; Analise estratigrafica e geoestatistica de reservatorios deltaicos da Bacia do Reconcavo (BA)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Carlos Moreira

    1997-07-01

    This study presents the characterization of the external geometry of deltaic oil reservoirs, including the description of their areal distribution using geo statistic tools, such as variography and kriging. A high-resolution stratigraphic study was developed over a 25 km{sup 2} area, by using data from 276 closely-spaced wells of an oil-producer field from the Reconcavo Basin, northeastern Brazil. The studied succession records the progressive lacustrine transgression of a deltaic environment. Core data and stratigraphic cross sections suggest that the oil reservoirs are mostly amalgamated, delta-front lobes, and subordinately, crevasse deposits. Some important geometrical elements were recognized by the detailed variographic analysis developed for each stratigraphic unit (zone). The average width for the groups of deltaic lobes of one zone was measured from the variographic feature informally named as hole effect. This procedure was not possible for the other zones due to the intense lateral amalgamation of sandstones, indicated by many variographic nested structures. Net sand krigged maps for the main zones suggest a NNW-SSE orientation for the deltaic lobes, as also their common amalgamation and compensation arrangements. High-resolution stratigraphic analyses should include a more regional characterization of the depositional system that comprises the studied succession. On the other hand, geostatistical studies should be developed only after the recognition of the depositional processes acting in the study area and the geological meaning of the variable to be treated, including its spatial variability scales as a function of sand body thickness, orientation and amalgamation. (author)

  5. Lithostratigraphy and volcanology of the Serra Geral Group, Paraná-Etendeka Igneous Province in Southern Brazil: Towards a formal stratigraphical framework

    Science.gov (United States)

    Rossetti, Lucas; Lima, Evandro F.; Waichel, Breno L.; Hole, Malcolm J.; Simões, Matheus S.; Scherer, Claiton M. S.

    2018-04-01

    The volcanic rocks of the Lower Cretaceous Paraná-Etendeka Igneous Province, in Brazil, are grouped in the Serra Geral Group. The province can be chemically divided into low-TiO2, and high-TiO2. In southern Brazil, the low-TiO2 lava pile reaches a thickness of 1 km and is formed of heterogeneous lava packages here divided into four lava formations. Torres Formation (TF) is characterized by chemically more primitive basaltic (> 5 wt% MgO) compound pahoehoe flow fields; these lavas stratigraphically overly aeolian sandstones of Botucatu Formation and represent the onset of the volcanic activity. Vale do Sol Formation (VSF) groups vertically stacked sheet-like rubbly pahoehoe basaltic andesites (SiO2 > 51 wt%; MgO < 5 wt%). These lavas covered the former basalts in the Torres Syncline axis and pinch out towards southwest and represent the most voluminous mafic lava flows. Dacites and rhyolites of Palmas Formation (PF) overlay VSF flows in the central and eastern outcrop area and rest directly upon TF lavas in the west. The acidic units were emplaced as lava domes and widespread tabular lava flows. Esmeralda Formation (EF) is the upper stratigraphic unit and it is formed by a basaltic pahoehoe flow field emplaced during the waning phase of volcanic activity of the low-TiO2 lava sequence. Sedimentary interbeds are preserved throughout the whole lava pile and were deposited during quiescence periods of volcanic activity, and represent important stratigraphic markers (e.g. TF-VSF contact). The newly proposed stratigraphy provides promptly recognized stratigraphic units in a regional framework of fundamental importance for future correlations and provide vital information in the understanding of how the Paraná-Etendeka Igneous Province evolved through time.

  6. Stratigraphic architecture of a fluvial-lacustrine basin-fill succession at Desolation Canyon, Uinta Basin, Utah: Reference to Walthers’ Law and implications for the petroleum industry

    Science.gov (United States)

    Ford, Grace L.; David R. Pyles,; Dechesne, Marieke

    2016-01-01

    A continuous window into the fluvial-lacustrine basin-fill succession of the Uinta Basin is exposed along a 48-mile (77-kilometer) transect up the modern Green River from Three Fords to Sand Wash in Desolation Canyon, Utah. In ascending order the stratigraphic units are: 1) Flagstaff Limestone, 2) lower Wasatch member of the Wasatch Formation, 3) middle Wasatch member of the Wasatch Formation, 4) upper Wasatch member of the Wasatch Formation, 5) Uteland Butte member of the lower Green River Formation, 6) lower Green River Formation, 7) Renegade Tongue of the lower Green River Formation, 8) middle Green River Formation, and 9) the Mahogany oil shale zone marking the boundary between the middle and upper Green River Formations. This article uses regional field mapping, geologic maps, photographs, and descriptions of the stratigraphic unit including: 1) bounding surfaces, 2) key upward stratigraphic characteristics within the unit, and 3) longitudinal changes along the river transect. This information is used to create a north-south cross section through the basin-fill succession and a detailed geologic map of Desolation Canyon. The cross section documents stratigraphic relationships previously unreported and contrasts with earlier interpretations in two ways: 1) abrupt upward shifts in the stratigraphy documented herein, contrast with the gradual interfingering relationships proposed by Ryder et al., (1976) and Fouch et al., (1994), 2) we document fluvial deposits of the lower and middle Wasatch to be distinct and more widespread than previously recognized. In addition, we document that the Uteland Butte member of the lower Green River Formation was deposited in a lacustrine environment in Desolation Canyon.

  7. The role of sediment supply in large-scale stratigraphic architecture of ancient Gilbert-type deltas (Pliocene Siena-Radicofani Basin, Italy)

    Science.gov (United States)

    Martini, Ivan; Ambrosetti, Elisa; Sandrelli, Fabio

    2017-04-01

    Aggradation, progradation and retrogradation are the main patterns that define the large-scale architecture of Gilbert-type deltas. These patterns are governed by the ratio between the variation in accommodation space and sediment supply experienced during delta growth. Sediment supply variations are difficult to estimate in ancient settings; hence, it is rarely possible to assess its significance in the large-scale stratigraphic architecture of Gilbert-type deltas. This paper presents a stratigraphic analysis of a Pliocene deltaic complex composed of two coeval and narrowly spaced deltaic branches. The two branches recorded the same tectonic- and climate-induced accommodation space variations. As a result, this deltaic complex represents a natural laboratory for testing the effects of sediment supply variations on the stratigraphic architecture of Gilbert-type deltas. The field data suggest that a sediment supply which is able to counteract the accommodation generated over time promotes the aggradational/progradational attitude of Gilbert-type deltas, as well as the development of thick foreset deposits. By contrast, if the sediment supply is not sufficient for counterbalancing the generated accommodation, an aggradational/retrogradational stratigraphic architecture is promoted. In this case, the deltaic system is forced to withdraw during the different phases of generation of accommodation, with the subsequent flooding of previously deposited sub-horizontal topset deposits (i.e., the delta plain). The subsequent deltaic progradation occurs above these deposits and, consequently, the available space for foresets growth is limited to the water depth between the base-level and the older delta plain. This leads to the vertical stacking of relatively thin deltaic deposits with an overall aggradatational/retrogradational attitude.

  8. Endise USA vastuluuraja naasmine / Priit Pullerits

    Index Scriptorium Estoniae

    Pullerits, Priit, 1965-

    2008-01-01

    USA poliitikateaduste professorist Christopher L. Kukest, kes käesoleval õppeaastal töötab Fulbright Scholar programmi stipendiaadina Tartu Ülikoolis. Lisa: CV. Kommenteerib Tartu Ülikooli riigiteaduste instituudi doktorant Mihkel Solvak

  9. Skandaal USAs : Obamat kujutati islamiterroristina / Aadu Hiietamm

    Index Scriptorium Estoniae

    Hiietamm, Aadu, 1954-

    2008-01-01

    The New Yorkeri esiküljel ilmus karikatuur, kus USA demokraatide presidendikandidaati Barack Obamat ja tema abikaasat Michelle'i kujutati islamiterroristidena, karikaturisti väitel joonistas ta selle Obama laimajate naeruvääristamiseks

  10. Ilves kritiseeris USA juhtidega Venemaad / Dagne Hanschmidt

    Index Scriptorium Estoniae

    Hanschmidt, Dagne

    2008-01-01

    Ilmunud ka: Postimees : na russkom jazõke 21. apr. lk. 4. President Toomas Hendrik Ilves kohtus töövisiidil Ameerika Ühendriikidesse USA asepresidendi Dick Cheney ja riigisekretär Condoleezza Rice'iga. Arutusel olid Euroopa Liidu suhted Venemaaga, Venemaa käitumine Gruusiaga, NATO viimase tippkohtumise tulemused. USA välisminister C. Rice avaldas Eesti presidendile tänu Eesti silmapaistva panuse eest Afganistanis. Kohtumisi kommenteerivad Riigikogu Euroopa Liidu asjade komisjoni esimees Marko Mihkelson ja Riigikogu väliskomisjoni esimees Sven Mikser. Vt. samas: Euroliit andis USA viisavabadusele rohelise tee. Euroopa Liidu sise- ja justiitsministrite kohtumisel kiideti heaks otsused, mis võimaldavad Eestil liituda USA viisavabadusprogrammiga. Vabariigi President töövisiidil Ameerika Ühendriikides 17.-23.04.2008

  11. LHV soovib USA-s kohtuvälist kokkulepet / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2005-01-01

    Kohtuväline kokkulepe LHV ja USA väärtpaberituru järelevalveasutuse SEC vahel tähendaks külmutatud väärtpaberikontode avamist, ent tõenäoliselt ka seda, et LHV peab maksma trahvi. Kohtuistungil USA-s esindavad LHV töötajaid Kristjan Lepikut ja Oliver Peeki advokaadid. Lisa: Teisedki on "sundpuhkusel"

  12. Punctuated Sediment Input into Small Subpolar Ocean Basins During Heinrich Events and Preservation in the Stratigraphic Record

    Science.gov (United States)

    Hesse, R.

    2006-12-01

    generated from fresh-water discharges into the sea that can produce reversed buoyancy, as is well known from experiments. When the flows have traveled long enough, their tops will have lost enough sediment by settling such that their density decreases below that of the ambient seawater causing the current tops to lift up. The turbid fresh-water clouds buoyantly rise out of the turbidity current to a level of equal density, presumably the pycnocline, where they spread out laterally, even up-current, and generate interflows that deposit graded layers. The process is slow enough to allow incorporation into the graded layers of debris melting out of drifting icebergs. The observed lofted depositional facies is exclusively found in Heinrich layers. The most likely candidates for the parent currents from which lofting occurred were the sandy flows that formed the sand abyssal plain. Through this stratigraphic relationship the lofted facies ties the main pulses of Late Pleistocene sediment supply in the Labrador Basin to Heinrich events. Dating of pelagic interlayers during future ocean drilling may provide the proof that packages of sand turbidites underlying the abyssal plain are correlated to individual Heinrich events. The correlation may thus be documented in the stratigraphic record. Similar situations may exist in the Bering Sea or along the Maury Channel System in North Atlantic.

  13. The stratigraphic imprint of a mid-Telychian (Llandovery, Early Silurian glaciation on far-field shallow-water carbonates, Anticosti Island, Eastern Canada

    Directory of Open Access Journals (Sweden)

    François Clayer

    2014-12-01

    Full Text Available The near-field stratigraphic record of the Early Silurian glaciations is well documented in the literature. Data from far-field areas are, however, sparse. One of the best far-field stratigraphic records of these Llandovery glaciations is exposed on Anticosti Island in eastern Canada. Eight shallow-water paleotropical facies are present close to the mid-Telychian Jupiter–Chicotte formational boundary along the south-central coast of Anticosti Island. These can be grouped into three facies associations that include, from bottom to top: a carbonate facies association (FA-1, a mixed siliciclastic and carbonate facies association (FA-2 and an encrinitic facies association (FA-3. These mid- to outer-ramp strata represent deposition mostly from episodic, high-energy storm events as evidenced by their sharp bases, hummocky cross-stratification, large wave ripples, gutter casts and wave-enhanced sediment gravity flow deposits. Superimposed on a long-term regressive trend, one main transgressive–regressive (TR sequence and four meter-scale TR cycles are evident, indicating a multi-order stratigraphic framework developed under the influence of glacio-eustasy. The Jupiter–Chicotte formational boundary, a regional discontinuity surface caused by a forced regression, corresponds to the onset of a far-field mid-Telychian glaciation.

  14. Prehistoric floods on the Tennessee River—Assessing the use of stratigraphic records of past floods for improved flood-frequency analysis

    Science.gov (United States)

    Harden, Tessa M.; O'Connor, Jim E.

    2017-06-14

    Stratigraphic analysis, coupled with geochronologic techniques, indicates that a rich history of large Tennessee River floods is preserved in the Tennessee River Gorge area. Deposits of flood sediment from the 1867 peak discharge of record (460,000 cubic feet per second at Chattanooga, Tennessee) are preserved at many locations throughout the study area at sites with flood-sediment accumulation. Small exposures at two boulder overhangs reveal evidence of three to four other floods similar in size, or larger, than the 1867 flood in the last 3,000 years—one possibly as much or more than 50 percent larger. Records of floods also are preserved in stratigraphic sections at the mouth of the gorge at Williams Island and near Eaves Ferry, about 70 river miles upstream of the gorge. These stratigraphic records may extend as far back as about 9,000 years ago, giving a long history of Tennessee River floods. Although more evidence is needed to confirm these findings, a more in-depth comprehensive paleoflood study is feasible for the Tennessee River.

  15. Status of image analysis methods to delineate stratigraphic position in the Topopah Spring Member of the Paintbrush Tuff, Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    Campbell, K.; Broxton, D.E.; Spaw, J.

    1989-10-01

    The Topopah Spring Member of the Paintbrush Tuff is an ash-flow cooling unit that is the candidate host rock for a potential high-level nuclear waste repository at Yucca Mountain, Nevada. The repository workings will be mostly confined to the member's rhyolitic portion, which is chemically homogenous but texturally variable. This report describes the status of work to develop a useful internal stratigraphy for the rhyolitic portion of the member; our approach is to use an image analysis technique to map textural variations within the member as a function of stratigraphic height. Fifteen petrographic thin sections of Topopah Spring rhyolitic tuff were studied in each of two drill holes (USW GU-3 and USW G-4). Digital color images were collected in transmitted light for two scenes 1 cm on a side for each thin section. Objects within a scene were classified by color, and measurements of area, elongation, and roughness were determined for each object. Summary statistics were compiled for all measurements for each color component within a scene, and each variable was statistically examined for correlations with stratigraphic position. Our initial studies using image analysis have not yet produced a useful method for determining stratigraphic position within the Topopah Spring Member. Simplifications made in this preliminary application of image analysis may be largely responsible for these negative results. The technique deserves further investigation, and more detailed analysis of existing data is recommended. 9 refs., 11 figs., 4 tabs

  16. Use of stratigraphic models as soft information to constrain stochastic modeling of rock properties: Development of the GSLIB-Lynx integration module

    International Nuclear Information System (INIS)

    Cromer, M.V.; Rautman, C.A.

    1995-10-01

    Rock properties in volcanic units at Yucca Mountain are controlled largely by relatively deterministic geologic processes related to the emplacement, cooling, and alteration history of the tuffaceous lithologic sequence. Differences in the lithologic character of the rocks have been used to subdivide the rock sequence into stratigraphic units, and the deterministic nature of the processes responsible for the character of the different units can be used to infer the rock material properties likely to exist in unsampled regions. This report proposes a quantitative, theoretically justified method of integrating interpretive geometric models, showing the three-dimensional distribution of different stratigraphic units, with numerical stochastic simulation techniques drawn from geostatistics. This integration of soft, constraining geologic information with hard, quantitative measurements of various material properties can produce geologically reasonable, spatially correlated models of rock properties that are free from stochastic artifacts for use in subsequent physical-process modeling, such as the numerical representation of ground-water flow and radionuclide transport. Prototype modeling conducted using the GSLIB-Lynx Integration Module computer program, known as GLINTMOD, has successfully demonstrated the proposed integration technique. The method involves the selection of stratigraphic-unit-specific material-property expected values that are then used to constrain the probability function from which a material property of interest at an unsampled location is simulated

  17. Early Permian transgressive-regressive cycles: Sequence stratigraphic reappraisal of the coal-bearing Barakar Formation, Raniganj Basin, India

    Science.gov (United States)

    Bhattacharya, Biplab; Bhattacharjee, Joyeeta; Bandyopadhyay, Sandip; Banerjee, Sudipto; Adhikari, Kalyan

    2018-03-01

    The present research is an attempt to assess the Barakar Formation of the Raniganj Gondwana Basin, India, in the frame of fluvio-marine (estuarine) depositional systems using sequence stratigraphic elements. Analysis of predominant facies associations signify deposition in three sub-environments: (i) a river-dominated bay-head delta zone in the inner estuary, with transition from braided fluvial channels (FA-B1) to tide-affected meandering fluvial channels and flood plains (FA-B2) in the basal part of the succession; (ii) a mixed energy central basin zone, which consists of transitional fluvio-tidal channels (FA-B2), tidal flats, associated with tidal channels and bars (FA-B3) in the middle-upper part of the succession; and (iii) a wave-dominated outer estuary (coastal) zone (FA-B4 with FA-B3) in the upper part of the succession. Stacked progradational (P1, P2)-retrogradational (R1, R2) successions attest to one major base level fluctuation, leading to distinct transgressive-regressive (T-R) cycles with development of initial falling stage systems tract (FSST), followed by lowstand systems tract (LST) and successive transgressive systems tracts (TST-1 and TST-2). Shift in the depositional regime from regressive to transgressive estuarine system in the early Permian Barakar Formation is attributed to change in accommodation space caused by mutual interactions of (i) base level fluctuations in response to climatic amelioration and (ii) basinal tectonisms (exhumation/sagging) related to post-glacial isostatic adjustments in the riftogenic Gondwana basins.

  18. THE TYRRHENIAN SECTION OF SAN GIOVANNI DI SINIS (SARDINIA:STRATIGRAPHIC RECORD OF AN IRREGULAR SINGLE HIGH STAND

    Directory of Open Access Journals (Sweden)

    LUCIANO LECCA

    2007-11-01

    Full Text Available A new analysis of the most representative Upper Pleistocene (Tyrrhenian, MIS 5e section of San Giovanni di Sinis (Oristano, Sardinia has provided a more detailed genetic stratigraphy of a low wave energy beach and temperate lagoon up to emerged peri-lagoonal facies deposits. These peri-lagoonal facies contain remains of fossil vertebrates, which, though few and fragmentary, bear witness to an at least temporary freshwater palaeoenvironment and the presence of deers and terrapins. Besides, the stratigraphy of this outcrop shows shoreface-backshore sandstones overlaying an erosion surface cut on the vertebrate-bearing layers. Facies analysis and sequence stratigraphy of the succession have provided support to a new eustatic interpretation significance. In fact, there appears to be evidence of one irregular single eustatic highstand, rather than two eustatic peaks as previously believed. The facies evolution and the local stratigraphic disconformities are interpreted as being associated with a lateral shift of the depositional environment within the same system formed during the MIS 5e sea level variations. As sea water level continued to rise so an erosional unconformity, caused by wave ravinement, formed between the low wave energy beach-lagoon sequence and the successive wave dominated beach facies sequence. This interpretation is supported by comparison with other sections of the Tyrrhenian in western Sardinia. The maximum sea level attained during the Tyrrhenian stage is a clear indication of a warm-temperate climate which can be correlated to the well known orbital interglacial configuration when the eustatic signal of Greenland's ice sheet melting occurred. SHORT NOTES

  19. Depositional features and stratigraphic sections in granitic plutons: implications for the emplacement and crystallization of granitic magma

    Science.gov (United States)

    Wiebe, R. A.; Collins, W. J.

    1998-09-01

    Many granitic plutons contain sheet-like masses of dioritic to gabbroic rocks or swarms of mafic to intermediate enclaves which represent the input of higher temperature, more mafic magma during crystallization of the granitic plutons. Small-scale structures associated with these bodies (e.g. load-cast and compaction features, silicic pipes extending from granitic layers into adjacent gabbroic sheets) indicate that the sheets and enclave swarms were deposited on a floor of the magma chamber (on granitic crystal mush and beneath crystal-poor magma) while the mafic magma was incompletely crystallized. These structures indicate 'way up', typically toward the interior of the intrusions, and appear to indicate that packages of mafic sheets and enclave concentrations in these plutons are a record of sequential deposition. Hence, these plutons preserve a stratigraphic history of events involved in the construction (filling, replenishment) and crystallization of the magma chamber. The distinctive features of these depositional portions of plutons allow them to be distinguished from sheeted intrusions, which usually preserve mutual intrusive contacts and 'dike-sill' relations of different magma types. The considerable thickness of material that can be interpreted as depositional, and the evidence for replenishment, suggest that magma chamber volumes at any one time were probably much less than the final size of the pluton. Thus, magma chambers may be constructed much more slowly than presently envisaged. The present steep attitudes of these structures in many plutons may have developed gradually as the floor of the chamber (along with the underlying solidified granite and country rock) sank during continuing episodes of magma chamber replenishment. These internal magmatic structures support recent suggestions that the room problem for granites could be largely accommodated by downward movement of country rock beneath the magma chamber.

  20. La Galite Archipelago (Tunisia, North Africa): Stratigraphic and petrographic revision and insights for geodynamic evolution of the Maghrebian Chain

    Science.gov (United States)

    Belayouni, Habib; Brunelli, Daniele; Clocchiatti, Roberto; Di Staso, Angelida; El Hassani, Iz-Eddine El Amrani; Guerrera, Francesco; Kassaa, Samia; Ouazaa, Nejia Laridhi; Martín, Manuel Martín; Serrano, Francisco; Tramontana, Mario

    2010-01-01

    The location of the La Galite Archipelago on the Internal/External Zones of the Maghrebian Chain holds strong interest for the reconstruction of the geodynamic evolution of the Mesomediterranean Microplate-Africa Plate Boundary Zone. New stratigraphic and petrographic data on sedimentary successions intruded upon by plutonic rocks enabled a better definition of the palaeogeographic and palaeotectonic evolutionary model of the area during the early-middle Miocene. The lower Miocene sedimentary units ( La Galite Flysch and Numidian-like Flysch) belong to the Mauritanian (internal) and Massylian (external) sub-Domains of the Maghrebian Chain, respectively. These deposits are related to a typical syn-orogenic deposition in the Maghrebian Flysch Basin Domain, successively backthrusted above the internal units. The backthrusting age is post-Burdigalian (probably Langhian-Serravallian) and the compressional phase represents the last stage in the building of the accretionary wedge of the Maghrebian orogen. These flysch units may be co-relatable to the similar well-known formations along the Maghrebian and Betic Chains. The emplacement of potassic peraluminous magmatism, caused local metamorphism in the Late Serravallian-Early Tortonian (14-10 Ma), after the last compressional phase (backthrusting), during an extensional tectonic event. This extensional phase is probably due to the opening of a slab break-off in the deep subduction system. La Galite Archipelago represents a portion of the Maghrebian Flysch Basin tectonically emplaced above the southern margin of the "Mesomediterranean Microplate" which separated the Piemontese-Ligurian Ocean from a southern oceanic branch of the Tethys (i.e. the Maghrebian Flysch Basin). The possible presence of an imbricate thrust system between La Galite Archipelago and northern Tunisia may be useful to exclude the petroleum exploration from the deformed sectors of the offshore area considered.

  1. Improving the Hydro-stratigraphic Model of the Oxnard Forebay, Ventura County, California, using Transient Electromagnetic Surveying

    Science.gov (United States)

    Quady, Maura Colleen

    2013-01-01

    To characterize the hydro-stratigraphy of an area, drilling and well logs provide high resolution electrical resistivity data, albeit for limited areas (points). The expense of drilling indirectly leads to sparse data and it is necessary to assume lateral homogeneity between wells when creating stratigraphic maps. Unfortunately, this assumption may not apply to areas in complex depositional and tectonically active settings. The goal of this study is to fill in data gaps between wells in a groundwater basin in order to better characterize the hydro-stratigraphy under existing and potential sites for managed aquifer recharge. Basins in the southern California study area have been used for decades to recharge surface water to an upper aquifer system; this work also addresses whether the local hydro-stratigraphy favors surface infiltration as a means to recharge water to the lower aquifer system. Here, soundings of transient electromagnetism (TEM), a surface geophysical method, are correlated with nearby down-hole resistivity and lithology well logs for grain size interpretations of the subsurface in unsaturated conditions. Grain size is used as a proxy for permeability (hydraulic conductivity), with resistivity contrasts highlighting variations in the media, which would affect groundwater flow in both vertical and horizontal directions. Results suggest a nearly horizontal, extensive, low permeability layer exists in the area and only a few noted locations are favorable for surface -to-lower aquifer system recharge. Furthermore, zones of higher permeability deeper than the upper aquifer system are discontinuous and isolated among lower permeability zones. However, the TEM profiles show areas where lower permeability zones are thin, and where alternatives to surface percolation methods could be explored. In addition, the survey adds information about the transition between the upper and lower aquifer systems, and adds detail to the topography of the base of freshwater

  2. Late Miocene ignimbrites at the southern Puna-northern Sierras Pampeanas border (˜27°S): Stratigraphic correlation

    Science.gov (United States)

    Montero-López, Carolina; Guzmán, Silvina; Barrios, Fabiola

    2015-10-01

    New field observations and petrographic and geochemical data of pyroclastic deposits exposed along the Las Papas valley (border between southern Puna and northern Sierras Pampeanas, Argentina) and further north, lead us to propose a new stratigraphic correlation and classification of the late Miocene volcanism in this area. We redefine the Las Papas, Las Juntas, Aguada Alumbrera and Rosada ignimbrites and define the Agua Caliente and Del Medio ignimbrites. The whole set of ignimbrites are rhyolites and less frequently dacites of calc-alkaline affinity. In the present contribution we divide ignimbrites into the Agua Negra and Rincón groups, based mainly on their geochemical signature. The Agua Negra Group is formed by the Las Papas and Las Juntas ignimbrites, indurated and welded, lithic-rich, with crystal-poor pumices and crystal-rich matrix. The Rincón Group comprises the Agua Caliente, Aguada Alumbrera, Rosada and Del Medio ignimbrites, with variable welding degrees, lithic and crystal content. The greater enrichment of crystals in the matrix in comparison with the crystal content in pumices indicates significant elutriation during flow transport and thus volume estimations are to be considered lower bounds for the actual erupted volume. The total minimum estimated volume for the ignimbrites of the Agua Negra and Rincón groups is 2.8 km3 (2.3 km3 DRE). Field relationships and new analytical data indicate that the different acid ignimbrites that crop out in this small area are related to at least two different magma chambers. The widespread Quaternary volcanism in this area covers the older deposits, thus making it difficult to recognize the volcanic centers that produced these late Miocene ignimbrites.

  3. STRATIGRAPHIC EVOLUTION, PALEOENVIRONMENTS AND HYDROCARBON POTENTIALS OF THE BENUE/DAHOMEY BASINS, NIGERIAN AND POTIGUAR/CEARA BASINS, NE BRAZIL

    International Nuclear Information System (INIS)

    Akande, S.O; Adekeye, O.A.; Oj, O.J; Erdtmann, B.D.; Koutsokous, E.I.

    2004-01-01

    The stratigraphy, facies relationship and paleoenvironment of selected West African and the Brazillian rift basins permit the recognition of at least two major petroleum systems apart from the prolific Niger Delta petroleum system. The Lower Cretaceous fluivio-lacustrine petroleum system and Upper Cretaceous to Lower Tertiary, marine dominated petroleum system. Our combined studies of the stratigraphic, structural framework, paleoenvironment and time-space relationships of the petroleum systems in the Benue/Dahomey and the Potiguar/Ceara basins indicated that rifting and subsequent drifting during the opening of the South Atlantic controlled subsidence, sediment deposition and facies associations in individual basins. Whereas in the Potiguar/Ceara basins, the best developed source rocks are within the Neomacin-Aptian fluvio- lacustrine sequence of the Pendencia and Alagamar Formations which generated reserved hydrocarbon in the Acu Formation, empirical evidence for this petroleum system in the contiguous Benue/Dahomey basins are only based on the geochemical characteristics of the lower parts of the Bima Formation and the Abeokuta Group. In contrast, the Upper Cretaceous-Lower Tertiary marine petroleum system, which is constrained by poor development of reservoirs in the Potiguar/Ceara basin is productive in the Benue/Dahomey basins where source rocks, reservoir and sealing facies occur at this interval. Considering the recent hydrocarbon discoveries of the East Niger basin, the Doba (southern Chad), the Muglad basin (southern Sudan) sourced from the fluvio-lacustrine rift sequences, we suggest that this petroleum system needs more detailed exploration and has some potentials in the Benue/Dahomey frontier basins

  4. USA võtab hoogu maha / Tarvo Vaarmets

    Index Scriptorium Estoniae

    Vaarmets, Tarvo

    2010-01-01

    Pärast riiklike soodustuste lõppu koduostjatele on USA-s vähenenud kinnisvara soetamine, jaemüüjate käive langes juunis võrreldes maiga 0,5%. USA keskpanga presidendi Ben Bernanke hinnangul on USA majandus ebatavaliselt ebamäärane

  5. Quo vadis, USA dollar? : finantsturgude viimastest arengutest / Robert Liljequist

    Index Scriptorium Estoniae

    Liljequist, Robert

    2013-01-01

    Swedbank AB Soome strateegiajuht vastab küsimustele, mis puudutavad USA majandust alanud aastal, dollari n.-ö turvalise valuuta staatuse kaotamise ohtu, võlakirjade ostmise vähendamist ja selle mõju USA dollarile, Euroopa Keskpanga poliitika mõju euro ja USA dollari suhtele. Swebanki prognoos USA dollari kohta

  6. USA tahab Iraagilt täispuutumatust / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2008-01-01

    USA ja Iraagi läbirääkimised USA vägede staatuse üle venivad, USA soovib oma sõduritele täielikku immuniteeti. Iraak olevat nõus nende USA üksuste immuniteediga, kes on sõjalistes rajatistes või missioonil, milles on varem kokku lepitud

  7. Lahingustress ajab USA sõdurid jooma / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2007-01-01

    Ilmunud ka: Postimees : na russkom jazõke, 15. märts 2007, lk. 10. USA kaitseministeeriumi siseuurimuse kohaselt kasvas alkoholi kuritarvitamine tegevteenistuses olevate USA sõjaväelaste seas aastatel 2002-2005 enam kui 30%. Alkoholi ja uimastite tarvitamisest Iraagis ja Afganistanis teenivate USA sõdurite hulgas. Vt. samas: USA relvajõududes puhkes uus homoskandaal

  8. USA suursaadik : hirmud on alistanud lootuse / Toomas Sildam

    Index Scriptorium Estoniae

    Sildam, Toomas, 1961-

    2004-01-01

    Eestist lahkuv USA suursaadik Joseph de Thomas andis USA iseseisvuspäeva kõnes hinnangu Eesti toetusele Iraagis ja USA Iraagi-poliitikale. Parlamendiliige Eiki Berg USA suursaadiku kõnest. Vt. ka: Suursaadiku sõnum lk. 10

  9. An 18,000 year-long eruptive record from Volcán Chaitén, northwestern Patagonia: Paleoenvironmental and hazard-assessment implications

    Science.gov (United States)

    Alloway, Brent V.; Pearce, Nick J. G.; Moreno, Patricio I.; Villarosa, Gustavo; Jara, Ignacio; De Pol-Holz, Ricardo; Outes, Valeria

    2017-07-01

    The 2008 eruption of Volcán Chaitén (VCha) in northwestern Patagonia was the first explosive rhyolitic eruption to have occurred within a century and provided an unprecedented scientific opportunity to examine all facets of the eruption ranging from magma rheology/ascent rates to ash-fall effects on biota and infrastructure. Up to very recently it was thought that the latest eruption prior to the 2008 event occurred c. 9750 cal. a BP. Although a number of researchers have recognised additional eruptive products, but their stratigraphy, age, and geochemical attributes have not been systematically described and/or recorded. In this study, we provide a detailed examination of andic cover-beds and tephra-bearing lake sequences located both proximally and distally to VCha, which record a series of hitherto unknown rhyolitic eruptive products and place all previous observations firmly within a coherent stratigraphic framework. Through major- and trace-element glass shard geochemistry we are able to confidently verify eruptive source. A total of 20 discrete tephra beds are recognised, with at least 10 having widespread areal distributions and/or depositional imprints broadly comparable to, or greater than, the 2008-tephra event. This record indicates that VCha has been continuously but intermittently active as far back as the end of the Last Glacial Maximum (c. 18,000 cal a BP) with two dominant, genetically related magma types and an intermediary 'mixed' type. Before this the eruptive record has been largely obscured and/or erased by widespread Andean piedmont glaciation. However, based on the tempo of VCha activity over the last c. 18,000 years, older VCha eruptives can be anticipated to occur as well as future hazardous explosive events. The new eruptive inventory will ultimately be useful for correlating equivalent-aged sequences and refining long-term eruptive tempo as well as corresponding temporal changes in magmatic evolution.

  10. Stratigraphic reconstruction of two debris avalanche deposits at Colima Volcano (Mexico): Insights into pre-failure conditions and climate influence

    Science.gov (United States)

    Roverato, M.; Capra, L.; Sulpizio, R.; Norini, G.

    2011-10-01

    Throughout its history, Colima Volcano has experienced numerous partial edifice collapses with associated emplacement of debris avalanche deposits of contrasting volume, morphology and texture. A detailed stratigraphic study in the south-eastern sector of the volcano allowed the recognition of two debris avalanche deposits, named San Marcos (> 28,000 cal yr BP, V = ~ 1.3 km 3) and Tonila (15,000-16,000 cal yr BP, V = ~ 1 km 3 ). This work sheds light on the pre-failure conditions of the volcano based primarily on a detailed textural study of debris avalanche deposits and their associated pyroclastic and volcaniclastic successions. Furthermore, we show how the climate at the time of the Tonila collapse influenced the failure mechanisms. The > 28,000 cal yr BP San Marcos collapse was promoted by edifice steep flanks and ongoing tectonic and volcanotectonic deformation, and was followed by a magmatic eruption that emplaced pyroclastic flow deposits. In contrast, the Tonila failure occurred just after the Last Glacial Maximum (22,000-18,000 cal BP) and, in addition to the typical debris avalanche textural characteristics (angular to sub-angular clasts, coarse matrix, jigsaw fit) it shows a hybrid facies characterized by debris avalanche blocks embedded in a finer, homogenous and partially cemented matrix, a texture more characteristic of debris flow deposits. The Tonila debris avalanche is directly overlain by a 7-m thick hydromagmatic pyroclastic succession. Massive debris flow deposits, often more than 10 m thick and containing large amounts of tree trunk logs, represent the top unit in the succession. Fluvial deposits also occur throughout all successions; these represent periods of highly localized stream reworking. All these lines of evidence point to the presence of water in the edifice prior to the Tonila failure, suggesting it may have been a weakening factor. The Tonila failure appears to represent an anomalous event related to the particular climatic

  11. Topographic Growth, the Development of Rivers and Implications for the Marine Stratigraphic Record in SE Asia (Invited)

    Science.gov (United States)

    Clift, P. D.; Zheng, H.

    2013-12-01

    that are unrelated to either of the local tectonics or regional climate change. Only the Pearl River appears to be unaffected by the evolving topography. Provenance in its offshore basins indicates a constant source in southern China, albeit one that expands gradually inland after the rifting of the South China Sea, but without any major capture events on the scale seen in other Asian river systems. Presently the origin of the Mekong is the most enigmatic, because the marine stratigraphic record suggests its initiation during the late Miocene, at least in the present position.

  12. Timing of the Toarcian Ocean Anoxic Event (Early Jurassic) from correlation of astronomically forced global stratigraphic sections

    Science.gov (United States)

    Huang, C.; Hinnov, L. A.; Hesselbo, S. P.

    2012-12-01

    The Early Toarcian Oceanic Anoxic Event (OAE) in the Early Jurassic Period is associated with a major negative carbon isotope excursion (CIE), mass extinction, marine transgression and global warming. The Toarcian OAE is thought to have been caused by flood basalt magmatism, and may have been a trigger for mass extinction. However, these proposed causes of the Toarcian OAE and associated biotic crisis are not adequately resolved by a precise chronology. The duration of the Toarcian OAE has been estimated to be anywhere from ~0.12 to ~0.9 Myr, most recently 0.74 to 3.26 Myr from U-Pb dating. The CIE associated with the Toarcian OAE has a similar pattern at numerous localities, and there is evidence for astronomical forcing of marine carbon isotopes. Here we estimate a duration of ~625 kyr for the main negative CIE, ~860 kyr for the polymorphum zone and >1.58 Myr for the levisoni zone based on 405-kyr astronomical eccentricity tuning of the marine section at Peniche (Portugal). This 405-kyr tuned series provides a ~2.5 Myr continuous high-resolution chronology through the Early Toarcian. There are 6, or possibly 7 short eccentricity cycles in the main CIE interval at Peniche. To confirm this astronomically based estimate, we analyzed five other sections at Yorkshire (UK), Dotternhausen (Germany), Valdorbia (Italy), Mechowo (Poland) and Serrucho, Neuquén (Argentina), from marine and terrestrial carbon isotopic series. These six stratigraphic sections from Early Jurassic western Tethys and eastern Panthalassa record the Toarcian OAE with ~6 prominent carbon isotope cycles in the CIE that provide us a 600 ± 100 kyr duration. The Peniche 405 kyr-tuned series indicates that the pre- and post-CIE intervals experienced strong precession-eccentricity-forced climate change, whereas the CIE interval is marked by dominant obliquity forcing. These dramatic and abrupt changes in astronomical response in the carbon isotopes point to fundamental shifting in the Early Toarcian

  13. Stratigraphic distribution of veins in the Murray and Stimson formations, Gale crater, Mars: Implications for ancient groundwater circulation

    Science.gov (United States)

    Nachon, M.; Sumner, D. Y.; Borges, S. R.; Stack, K.; Stein, N.; Watkins, J. A.; Banham, S.; Rivera-Hernandez, F.; Wiens, R. C.; l'Haridon, J.; Rapin, W.; Kronyak, R. E.

    2017-12-01

    Since landing at Gale crater, Mars, in August 2012, the Curiosity rover has driven through more than 300m of stratigraphy. From the first to the most recent sedimentary rocks explored, light-toned veins have been observed cutting the host-rock and were interpreted as diagenetic features emplaced by hydraulic fracturing. Chemical and mineralogical analyses show they consist of Ca-sulfate. Here we report on the veins' distribution within two geological formations explored more recently by the rover: (a) the Murray Formation that consists mainly of fine-grained laminated rocks that have been interpreted as having been deposited in a former lacustrine environment [1], and (b) the Stimson Formation, which lies unconformably above the Murray, and consists of cross bedded sandstones interpreted as being deposited in a aeolian environment [2]. We have performed a systematic observation of the veins within the MastCam images, from the base of the Murray (Sol 750) up to Sol 1515 [3], described their main geometrical characteristics (e.g. orientation to laminae, relative density, branching). Five veins facies were defined based on veins' geometrical properties, abundance, and host-rock grain size. The distribution of veins facies was placed within the broader stratigraphic context. The distribution of veins within the Murray and Stimson Formations shows strong rheological controls. In the Murray, light-toned veins are present from the basal part of the section up to the most recently explored exposures. Several dense vein outcrops are associated with local variations in host-rock type, suggesting rheological control of fluid circulation. In Stimson sandstones, light-toned veins are also present though much rarer, again possibly due to rheological properties. The light-toned veins represent post depositional fluid circulation, occurring after accumulation of the lacustrine Murray rocks; at least some veins formed after Murray's burial, erosion, and the deposition and

  14. Quebec-USA electricity export contracts

    International Nuclear Information System (INIS)

    Labbe, J.-F.

    1993-06-01

    Electricity exports from Hydro-Quebec to utilities in the USA significantly affects the economy and environment of Quebec. These exports may be arranged under interconnection agreements to sell excess capacity and production during off-peak periods or under firm sales contracts. Hydro-Quebec exports could also replace power plants that would otherwise be needed in the USA. The economic environment for Hydro-Quebec exports to the USA is reviewed along with the regulatory environment applicable to international trade (General Agreement on Tariffs and Trade, Canada-USA Free Trade Agreement, North American Free Trade Agreement), Quebec (Canadian federal and provincial law), and the USA (federal and state law). A jurisdictional analysis of power export contracts is then presented, citing examples of contracts already signed by Hydro-Quebec with utilities in New York and New England. Contract law and contract provisions are discussed, including common clauses and particular clauses. Suggestions are made for new clauses that would improve the electricity trade. 215 refs., 13 figs., 3 tabs

  15. USA National Phenology Network observational data documentation

    Science.gov (United States)

    Rosemartin, Alyssa H.; Denny, Ellen G.; Gerst, Katharine L.; Marsh, R. Lee; Posthumus, Erin E.; Crimmins, Theresa M.; Weltzin, Jake F.

    2018-04-25

    The goals of the USA National Phenology Network (USA-NPN, www.usanpn.org) are to advance science, inform decisions, and communicate and connect with the public regarding phenology and species’ responses to environmental variation and climate change. The USA-NPN seeks to advance the science of phenology and facilitate ecosystem stewardship by providing phenological information freely and openly. To accomplish these goals, the USA-NPN National Coordinating Office (NCO) delivers observational data on plant and animal phenology in several formats, including minimally processed status and intensity datasets and derived phenometrics for individual plants, sites, and regions. This document describes the suite of observational data products delivered by the USA National Phenology Network, covering the period 2009–present for the United States and accessible via the Phenology Observation Portal (http://dx.doi.org/10.5066/F78S4N1V) and via an Application Programming Interface. The data described here have been used in diverse research and management applications, including over 30 publications in fields such as remote sensing, plant evolution, and resource management.

  16. Hvad SKER der med drikkevandet i USA?

    DEFF Research Database (Denmark)

    Ramsay, Loren Mark

    2017-01-01

    Forskellige lande har forskellige traditioner indenfor drikkevandsbehandling. Denne beretning fra ”Water Quality Technology Conference” i USA er set med en særlig vinkel, da forfatteren er amerikansk statsborger, men har arbejdet i den danske vandbranche i mere end 25 år.......Forskellige lande har forskellige traditioner indenfor drikkevandsbehandling. Denne beretning fra ”Water Quality Technology Conference” i USA er set med en særlig vinkel, da forfatteren er amerikansk statsborger, men har arbejdet i den danske vandbranche i mere end 25 år....

  17. Storm-related sedimentation influenced by coastal configuration in the stratigraphic record of a tectonically active shelf (Upper Pleistocene Le Castella terrace, Italy)

    Science.gov (United States)

    Nalin, Ronald; Massari, Francesco

    2018-03-01

    Analysis of patterns of coastal circulation and sediment dispersal is an essential step for the study of controlling factors influencing the long-term dynamics of coastal systems. Modern settings offer the possibility to monitor relevant parameters over relatively short time spans. However, geological examples complement this perspective by providing a time-averaged record where longer trends and stratigraphically significant processes can be evaluated. This study investigates the shallow marine deposits of Le Castella terrace (Upper Pleistocene, southern Italy) to document how patterns of circulation influenced by coastline configuration can affect the preserved millennial-scale depositional record of a progradational shoreline system. The regressive portion of the Le Castella terrace deposits, developed during a relative sea-level highstand and falling stage, consists of a progradational wedge mainly composed of redistributed skeletal particles of a coeval shallow water carbonate factory. Preservation of the morphology of the paleocoastline and abundant current-related sedimentary structures allow reconstruction of the predominant sediment dispersal dynamics responsible for the formation of this sedimentary wedge. Facies and paleocurrent analysis indicate offshore and alongshore sediment transport modes, consistent with coastal circulation driven by storms normally incident to the shoreline and a sharp change in coastline orientation. This coastal inflection influenced circulation patterns causing flow separation and eddy formation in the lee of the curved coastline. Syndepositional tectonic deformation also affected the architecture of the preserved deposits, controlling the nucleation and development of a clinostratified body and determining localized lateral stratigraphic variability. This study illustrates how transient but recurrent circulation patterns associated with changes in coastal orientation and related to high-energy storm events can leave a

  18. Facies associations, depositional environments and stratigraphic framework of the Early Miocene-Pleistocene successions of the Mukah-Balingian Area, Sarawak, Malaysia

    Science.gov (United States)

    Murtaza, Muhammad; Rahman, Abdul Hadi Abdul; Sum, Chow Weng; Konjing, Zainey

    2018-02-01

    Thirty-five stratigraphic section exposed along the Mukah-Selangau road in the Mukah-Balingian area have been studied. Sedimentological and palynological data have been integrated to gain a better insight into the depositional architecture of the area. Broadly, the Mukah-Balingian area is dominated by fluvial, floodplain and estuarine related coal-bearing deposits. The Balingian, Begrih and Liang formations have been described and interpreted in terms of seven facies association. These are: FA1 - Fluvial-dominated channel facies association; FA2 - Tide-influenced channel facies association; FA3 - Tide-dominated channel facies association; FA4 - Floodplain facies association; FA5 - Estuarine central basin-mud flats facies association; FA6 - Tidal flat facies association and FA7 - Coastal swamps and marshes facies association. The Balingian Formation is characterised by the transgressive phase in the base, followed by a regressive phase in the upper part. On the basis of the occurrence of Florscheutzia trilobata with Florscheutzia levipoli, the Early to Middle Miocene age has been assigned to the Balingian Formation. The distinct facies pattern and foraminifera species found from the samples taken from the Begrih outcrop imply deposition in the intertidal flats having pronounced fluvio-tidal interactions along the paleo-margin. Foraminiferal data combined with the pronounced occurrence of Stenochlaena laurifolia suggest at least the Late Miocene age for the Begrih Formation. The internal stratigraphic architecture of the Liang Formation is a function of a combination of sea level, stable tectonic and autogenic control. Based on stratigraphic position, the Middle Pliocene to Pleistocene age for the Liang Formation is probable. The Balingian, Begrih and Liang formations display deposits of multiple regressive-transgressive cycles while the sediments were derived from the uplifted Penian high and Rajang group.

  19. Milankovitch cyclicity in modern continental margins: stratigraphic cycles in terrigenous shelf settings; El registro de la ciclicidad de Milankovitch en margenes continentales actuales: ciclos estratigraficos en plataformas terrigenas

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, F. J.; Ridente, D.

    2013-06-01

    We present a synthesis of the sedimentary responses to Late Quaternary Milankovitch-type sea-level cycles (100 and 20 kyr periodicities) as a basis for our investigations into the patterns and concepts of composite sequences in shallow-shelf settings. We describe the record of both 100 and 20 kyr cycles as documented worldwide and discuss the pattern of composite cyclicity mainly on the basis of previously published data from the Adriatic Sea and Gulf of Cadiz margins. Cycles of 100 kyr are those most frequently documented in Quaternary margins; they occur in the form of unconformity-bounded depositional sequences dominated by fairly uniform pro gradational-regressive units and more variable, though less well developed, transgressive deposits. Sequence boundaries correspond to prominent polygenic (regressive-transgressive) erosional surfaces that bear witness to considerable transgressive reworking of the original sub-aerial unconformity. Although the progradational units making up the greater part of these sequences have usually been interpreted as a record of a falling sea-level stage, recent evidence is pointing towards a more complex stratigraphic picture, including a distinction between relative highstand and lowstand deposits. The 20-kyr stratigraphic motifs show greater variation compared to that displayed by the more common 100-kyr sequences, particularly in the basic structure of systems tracts and the nature of bounding surfaces. The two case studies described here, the Adriatic Sea and Gulf of Cadiz margins, highlight the fact that, concomitantly with an increase in frequencies of cycles and sequences, sediment supply and the dynamics of their dispersal significantly affected the stratigraphic response to the main controlling factor, which was sea-level, thus determining the variety of expression in the 20 kyr cycles. (Author)

  20. Late oligocene and miocene faulting and sedimentation, and evolution of the southern Rio Grande rift, New Mexico, USA

    Science.gov (United States)

    Mack, Greg H.; Seager, William R.; Kieling, John

    1994-08-01

    The distribution of nonmarine lithofacies, paleocurrents, and provenance data are used to define the evolution of late Oligocene and Miocene basins and complementary uplifts in the southern Rio Grande rift in the vicinity of Hatch, New Mexico, USA. The late Oligocene-middle Miocene Hayner Ranch Formation, which consists of a maximum of 1000 m of alluvial-fan, alluvial-flat, and lacustrine-carbonate lithofacies, was deposited in a narrow (12 km), northwest-trending, northeast-tilted half graben, whose footwall was the Caballo Mountains block. Stratigraphic separation on the border faults of the Caballo Mountains block was approximately 1615 m. An additional 854 m of stratigraphic separation along the Caballo Mountains border faults occurred during deposition of the middle-late Miocene Rincon Valley Formation, which is composed of up to 610 m of alluvial-fan, alluvial-flat, braided-fluvial, and gypsiferous playa lithofacies. Two new, north-trending fault blocks (Sierra de las Uvas and Dona Ana Mountains) and complementary west-northwest-tilted half graben also developed during Rincon Valley time, with approximately 549 m of stratigraphic separation along the border fault of the Sierra de las Uvas block. In latest Miocene and early Pliocene time, following deposition of the Rincon Valley Formation, movement continued along the border faults of the Caballo Mountains, Dona Ana Mountains, and Sierra de las Uvas blocks, and large parts of the Hayner Ranch and Rincon Valley basins were segmented into smaller fault blocks and basins by movement along new, largely north-trending faults. Analysis of the Hayner Ranch and Rincon Valley Formations, along with previous studies of the early Oligocene Bell Top Formation and late Pliocene-early Pleistocene Camp Rice Formation, indicate that the traditional two-stage model for development of the southern Rio Grande rift should be abandoned in favor of at least four episodes of block faulting beginning 35 Ma ago. With the exception of

  1. Early evolution of the southern margin of the Neuquén Basin, Argentina: Tectono-stratigraphic implications for rift evolution and exploration of hydrocarbon plays

    Science.gov (United States)

    D'Elia, Leandro; Bilmes, Andrés; Franzese, Juan R.; Veiga, Gonzalo D.; Hernández, Mariano; Muravchik, Martín

    2015-12-01

    Long-lived rift basins are characterized by a complex structural and tectonic evolution. They present significant lateral and vertical stratigraphic variations that determine diverse basin-patterns at different timing, scale and location. These issues cause difficulties to establish facies models, correlations and stratal stacking patterns of the fault-related stratigraphy, specially when exploration of hydrocarbon plays proceeds on the subsurface of a basin. The present case study corresponds to the rift-successions of the Neuquén Basin. This basin formed in response to continental extension that took place at the western margin of Gondwana during the Late Triassic-Early Jurassic. A tectono-stratigraphic analysis of the initial successions of the southern part of the Neuquén Basin was carried out. Three syn-rift sequences were determined. These syn-rift sequences were located in different extensional depocentres during the rifting phases. The specific periods of rifting show distinctly different structural and stratigraphic styles: from non-volcanic to volcanic successions and/or from continental to marine sedimentation. The results were compared with surface and subsurface interpretations performed for other depocentres of the basin, devising an integrated rifting scheme for the whole basin. The more accepted tectono-stratigraphic scheme that assumes the deposits of the first marine transgression (Cuyo Cycle) as indicative of the onset of a post-rift phase is reconsidered. In the southern part of the basin, the marine deposits (lower Cuyo Cycle) were integrated into the syn-rift phase, implying the existence of different tectonic signatures for Cuyo Cycle along the basin. The rift climax becomes younger from north to south along the basin. The post-rift initiation followed the diachronic ending of the main syn-rift phase throughout the Neuquén Basin. Thus, initiation of the post-rift stage started in the north and proceeded towards the south, constituting a

  2. Assessing New and Old Methods in Paleomagnetic Paleothermometry: A Test Case at Mt. St. Helens, USA

    Science.gov (United States)

    Bowles, J. A.; Gerzich, D.; Jackson, M. J.

    2017-12-01

    Paleomagnetic data can be used to estimate deposit temperatures (Tdep) of pyroclastic density currents (PDCs). The typical method is to thermally demagnetize oriented lithic clasts incorporated into the PDC. If Tdep is less than the maximum Curie temperature (Tc), the clast is partially remagnetized in the PDC, and the unblocking temperature (Tub) at which this remagnetization is removed is an estimate of Tdep. In principle, juvenile clasts can also be used, and Tub-max is taken as the minimum Tdep. This all assumes blocking (Tb) and unblocking temperatures are equivalent and that the blocking spectrum remains constant through time. Recent evidence shows that Tc in many titanomagnetites is a strong function of thermal history due to a crystal-chemical reordering process. We therefore undertake a study designed to test some of these assumptions and to assess the extent to which the method may be biased by a Tb spectrum that shifts to higher T during cooling. We also explore a new magnetic technique that relies only on stratigraphic variations in Tc. Samples are from the May 18, 1980 PDCs at Mt. St. Helens, USA. Direct temperature measurements of the deposits were 297 - 367°C. At sites with oriented lithics, standard methods provide a Tdep range that overlaps with measured temperatures, but is systematically higher by a few 10s of °C. By contrast, pumice clasts all give Tdep_min estimates that greatly exceed lithic estimates and measured temperatures. We attribute this overestimate to two causes: 1) Tc and Tub systematically increase with depth as a result of the reordering process. This results in Tdep_min estimates that vary by 50°C and increase with depth. 2) MSH pumice is multi-domain, where Tub > Tb, resulting in a large overestimate in Tdep. At 5 sites, stratigraphic variations in Tc were conservatively interpreted in terms of Tdep as 300°C. More sophisticated modeling of the time-temperature-depth evolution of Tc allows us to place tighter constraints on

  3. "Riia ring, "luurepost ja tööjaotus USA esindustest Baltikumis 1920. aastatel / Eero Medijainen""

    Index Scriptorium Estoniae

    Medijainen, Eero, 1959-

    2012-01-01

    Diplomaatilisest taustast. USA esinduste rajamisest Baltikumi. Olukorrast USA saatkonnas 1922. aastal. USA sõjalisest vaatlejast "Balti provintsides" 1919-1922. Luurekeskusest ja Sergius Riisist. "Vene sektsiooni" formaliseeerumisest.

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

    Science.gov (United States)

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

    2017-04-01

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

  5. Professional Training of Economists in the USA

    Science.gov (United States)

    Rudnitska, Kateryna

    2014-01-01

    The article deals with the peculiarities of American professional undergraduate and graduate training in economics. The analysis of documents, scientific and educational literature demonstrates the diversity of the US training courses and combinations of disciplines in economics. It has been defined that leading position of the USA in the world…

  6. Cultural-Based Development in the USA

    NARCIS (Netherlands)

    Tubadji, A.; Osoba, B.J.; Nijkamp, P.

    2015-01-01

    This paper explores the link between culture and regional development in USA counties by explicitly including an arts variable in an attitudes-driven culture-based development (CBD) production function. The main aims of the research are (1) to revisit the standard CBD model in order to examine

  7. Angiostrongylus cantonensis Meningitis and Myelitis, Texas, USA.

    Science.gov (United States)

    Al Hammoud, Roukaya; Nayes, Stacy L; Murphy, James R; Heresi, Gloria P; Butler, Ian J; Pérez, Norma

    2017-06-01

    Infection with Angiostrongylus cantonensis roundworms is endemic in Southeast Asia and the Pacific Basin. A. cantonensis meningitis and myelitis occurred in summer 2013 in a child with no history of travel outside of Texas, USA. Angiostrongyliasis is an emerging neurotropic helminthic disease in Texas and warrants increased awareness among healthcare providers.

  8. USA abandons K1 - or does it

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1985-01-01

    The controversy over the USA's Federal Radiological Preparedness Coordinating Committee (FRPCC) policy to distribute potassium iodide to emergency workers and institutionalised individuals in the event of a nuclear reactor accident but not to recommend the predistribution or stockpiling of potassium iodide for the general public is discussed. (U.K.)

  9. Gridded bathymetry of Penguin Bank, Hawaii, USA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (5 m cell size) of Penguin Bank, Hawaii, USA. The netCDF grid and ArcGIS ASCII file include multibeam bathymetry from the Simrad EM3002d, and...

  10. Babesia microti infection, eastern Pennsylvania, USA.

    Science.gov (United States)

    Acosta, Marcela E Perez; Ender, Peter T; Smith, Erin M; Jahre, Jeffrey A

    2013-07-01

    Infection with Babesia microti has not been well-described in eastern Pennsylvania, USA, despite the vector of this organism being prevalent. We report 3 cases of babesiosis in eastern Pennsylvania in persons without recent travel outside the region or history of blood transfusions, suggesting emergence of this infection.

  11. Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA.

    Science.gov (United States)

    Alrowais, Hind; McElheny, Christi L; Spychala, Caressa N; Sastry, Sangeeta; Guo, Qinglan; Butt, Adeel A; Doi, Yohei

    2015-11-01

    Fosfomycin resistance in Escherichia coli is rare in the United States. An extended-spectrum β-lactamase-producing E. coli clinical strain identified in Pennsylvania, USA, showed high-level fosfomycin resistance caused by the fosA3 gene. The IncFII plasmid carrying this gene had a structure similar to those found in China, where fosfomycin resistance is commonly described.

  12. Euroopa ja USA: liidus tulevikuks / Barack Obama

    Index Scriptorium Estoniae

    Obama, Barack, 1961-

    2010-01-01

    Ameerika Ühendriikide president kirjutab 19.-20. novembril Lissabonis toimuvast NATO tippkohtumisest, USA ja Euroopa vastastikusest vajalikkusest ning NATO-sisesest koostööst. Barack Obama leiab, et NATO ja Venemaa võiksid taaskäivitada oma suhted

  13. Recognition of Milankovitch cycles in the stratigraphic record:application of the CWT and the FFT to well-log data

    Institute of Scientific and Technical Information of China (English)

    YU Ji-feng; SUI Feng-gui; LI Zeng-xue; LIU Hua; WANG Yu-lin

    2008-01-01

    The authors applied a the combination of Continuous Wavelet Transform (CWT) and Fast Fourier Transform (FFF)methods to gamma ray well-log data from the Q3, G1 and D2 wells. This high-resolution stratigraphic study was based on Milankovitch's orbital cycle theory. It was found that the CWT scale factors, 'a,' of 12, 24 and 60 match the ratios of the periodicities of precession, obliquity and eccentricity very well. Nine intervals of the Permo-carboniferous strata were recognized to have Milankovitch cycles in them. For example, section A of well Q3 has 29 precession cycles, 15 obliquity cycles and 7 short eccentricity cycles. The wavelengths are 2.7, 4.4 and 7.8 m for precession, obliquity and eccentricity, respectively. Important geological parameters such as the stratigraphic completeness and the accumulation rate were also estimated. These results provide basic information for further cyclostratigraphic correlation studies in the area. They are of great significance for the study of ancient and future climate change.

  14. USA suursaadik : toetame Eestit / Stanley Davis Phillips ; interv. Erkki Bahovski

    Index Scriptorium Estoniae

    Phillips, Stanley Davis

    2007-01-01

    USA suursaadik Eestis Stanley Davis Phillips vastab küsimustele, mis puudutavad USA positsiooni Tõnismäe pronkssõduri suhtes, Eesti saatkonna piiramist Moskvas, USA ja Venemaa suhteid ning koostööd, sõda terrorismiga, USA kava paigutada Tšehhi ja Poolasse raketitõrjebaasid, Eesti presidendi Toomas Hendrik Ilvese visiiti USAsse. Lisa: Stanley Davis Phillips. Ilmunud ka: Postimees : na russkom jazõke 16. mai lk. 5

  15. Võidurelvastumise tagasitulek : USA kiiluvees Venemaa ja Hiina / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2007-01-01

    USA eelarvekavas on ette nähtud kaitsekulutuste jätkuv suurenemine, suureneda võib ka relvajõudude isikkoosseis. Relvajõududele kulub USA-s ligi 4% SKT-st. Globaalselt liidetuna tõusid kõikide riikide kulutused relvajõududele 1990. aasta tasemele. Hiina ja Venemaa kaitsekulutustest. Lisad: Aasia riigid kasvatavad sõjalisi kulutusi; 25 riigil pole oma sõjaväge. Graafik: USA sõjalised kulutused

  16. 3D stratigraphic forward modelling of Shu'aiba Platform stratigraphy in the Bu Hasa Field, Abu Dhabi, United Arab Emirates.

    Science.gov (United States)

    Hu, J.; Lokier, S. W.

    2012-04-01

    This paper presents the results of three dimensional sequence stratigraphic forward modelling of the Aptian age Shu'aiba Formation from Abu Dhabi, United Arab Emirates (UAE). The Shu'aiba Formation lies within the uppermost part of the Lower Cretaceous Thamama Group and forms one of the most prolific hydrocarbon reservoir intervals of the Middle East with production dating back to the 1960's. The Shu'aiba Formation developed as a series of laterally-extensive shallow-water carbonate platforms in an epeiric sea that extended over the northern margin of the African-Arabian Plate. This shallow sea was bounded by the Arabian Shield to the west and the passive margin with the Neo-Tethys Ocean towards the north and east (Droste, 2010). The exposed Arabian Shield acted as a source of siliciclastic sediments to westernmost regions, however, more offshore areas were dominated by shallow-water carbonate deposition. Carbonate production was variously dominated by Lithocodium-Baccinella, orbitolinid foraminifera and rudist bivalves depending on local conditions. While there have been numerous studies of this important stratigraphic interval (for examples see van Buchem et al., 2010), there has been little attempt to simulate the sequence stratigraphic development of the formation. During the present study modelling was undertaken utilising the CARBONATE-3D stratigraphic forward modelling software (Warrlich et al., 2008; Warrlich et al., 2002)) thus allowing for the control of a diverse range of internal and external parameters on carbonate sequence development. This study focuses on platform development in the onshore Bu Hasa Field - the first giant oilfield to produce from the Shu'aiba Formation in Abu Dhabi. The carbonates of the Bu Hasa field were deposited on the southwest slope of the intra-shelf Bab Basin, siliciclastic content is minor. Initially these carbonates were algal dominated with rudist mounds becoming increasingly important over time (Alsharhan, 1987

  17. USA-reis nõuab biomeetrilist passi / Tuuli Koch

    Index Scriptorium Estoniae

    Koch, Tuuli

    2004-01-01

    USA-s pikendati viisavabastusprogrammi biomeetrilise passi tähtaega 2005. aasta 26. oktoobrini. USA Eesti-saatkonna töötaja Christopher Smithi sõnul ei kehti viisavabadusprogrammi raames reisimise puhul passid, mida ei saa masinaga lugeda

  18. USA tunnistab valge fosfori relvana kasutamist Iraagis / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2005-01-01

    Kui varem USA eitas valge fosfori kasutamist Iraagis Falluja linnas, siis nüüd on ta eitamisest loobunud. USA välisministeeriumi pressiteate kohaselt ei kasutatud fosforit keemiarelvana. Sütitavate relvade kasutamine tsiviilisikute vastu on keelatud. Vt. samas: Ahto Lobjakas. Europarlamendis USA hukkamõist

  19. Tšehhid protestisid USA raketikilbi vastu / Igor Taro

    Index Scriptorium Estoniae

    Taro, Igor

    2007-01-01

    USA soovib rajada oma ballistiliste rakettide eest kaitsva süsteemi rajatisi Poola ja Tšehhi territooriumile, mille vastu on protestinud ka Venemaa. Tšehhi Trokaveci küla elanike korraldatud referendumist ja Prahas toimunud meeleavaldustest USA raketikilbi radarijaama vastu. Lisa: USA raketikilp

  20. 76 FR 35715 - Establishment of the SelectUSA Initiative

    Science.gov (United States)

    2011-06-20

    ... Establishment of the SelectUSA Initiative By the authority vested in me as President by the Constitution and the... unnecessary obstacles to investment. Sec. 2. SelectUSA Initiative. (a) Establishment. There is established the SelectUSA Initiative (Initiative), a Government-wide initiative to attract and retain investment in the...

  1. Genomic and transcriptomic differences in community acquired methicillin resistant Staphylococcus aureus USA300 and USA400 strains.

    Science.gov (United States)

    Jones, Marcus B; Montgomery, Christopher P; Boyle-Vavra, Susan; Shatzkes, Kenneth; Maybank, Rosslyn; Frank, Bryan C; Peterson, Scott N; Daum, Robert S

    2014-12-19

    Staphylococcus aureus is a human pathogen responsible for substantial morbidity and mortality through its ability to cause a number of human infections including bacteremia, pneumonia and soft tissue infections. Of great concern is the emergence and dissemination of methicillin-resistant Staphylococcus aureus strains (MRSA) that are resistant to nearly all β-lactams. The emergence of the USA300 MRSA genetic background among community associated S. aureus infections (CA-MRSA) in the USA was followed by the disappearance of USA400 CA-MRSA isolates. To gain a greater understanding of the potential fitness advantages and virulence capacity of S. aureus USA300 clones, we performed whole genome sequencing of 15 USA300 and 4 USA400 clinical isolates. A comparison of representative genomes of the USA300 and USA400 pulsotypes indicates a number of differences in mobile genome elements. We examined the in vitro gene expression profiles by microarray hybridization and the in vivo transcriptomes during lung infection in mice of a USA300 and a USA400 MRSA strain by performing complete genome qRT-PCR analysis. The unique presence and increased expression of 6 exotoxins in USA300 (12- to 600-fold) compared to USA400 may contribute to the increased virulence of USA300 clones. Importantly, we also observed the up-regulation of prophage genes in USA300 (compared with USA400) during mouse lung infection (including genes encoded by both prophages ΦSa2usa and ΦSa3usa), suggesting that these prophages may play an important role in vivo by contributing to the elevated virulence characteristic of the USA300 clone. We observed differences in the genetic content of USA300 and USA400 strains, as well as significant differences of in vitro and in vivo gene expression of mobile elements in a lung pneumonia model. This is the first study to document the global transcription differences between USA300 and USA400 strains during both in vitro and in vivo growth.

  2. Diagenetic Iron Cycling in Ancient Alkaline Saline Lacustrine Sedimentary Rocks: A Case Study on the Jurassic Brushy Basin Member of the Morrison Formation, Colorado Plateau, USA

    Science.gov (United States)

    Potter-McIntyre, S. L.; Chan, M. A.; McPherson, B. J. O. L.

    2014-12-01

    The upper part of the Brushy Basin Member in the Four Corners region of the U.S. was deposited in an ephemeral alkaline saline lake system with copious input of volcanic ash. The variegated shale formation provides a setting for the study of early diagenetic iron cycling that records the action of alkaline saline fluid chemistries reacting with volcaniclastic sediments in the presence of microbes. A bull's-eye pattern of authigenic minerals with increasing alteration towards the basinal center similar to modern alkaline saline lakes provides evidence for an extreme paleoenvironmental interpretation. The purpose of this research is to document specific factors, such as reactive sediments, microbial influences, and grain size that affect concretion formation and iron cycling in an ancient extreme environment. Three broad diagenetic facies are interpreted by color and associated bioturbation features: red, green and intermediate. Diagenetic facies reflect meter-scale paleotopography: red facies represent shallow water to subaerial, oxidizing conditions; green facies reflect saturated conditions and reducing pore water chemistry shortly after deposition, and intermediate facies represent a combination of the previous two conditions. Evidence of biotic influence is abundant and trace fossils exhibit patterns associated with the diagenetic facies. Red diagenetic facies typically contain burrows and root traces and green diagenetic facies exhibit restricted biotic diversity typically limited to algal molds (vugs). Microbial fossils are well-preserved and are in close proximity to specific iron mineral textures suggesting biotic influence on the crystal morphology. Three categories of concretions are characterized based on mineralogy: carbonate, iron (oxyhydr)oxide and phosphate concretions. Concretion mineralogy and size vary within an outcrop and even within a stratigraphic horizon such that more than one main category is typically present in an outcrop. Variation in

  3. High-temperature carbonates in the Stillwater Complex, Montana, USA

    Science.gov (United States)

    Aird, H. M.; Boudreau, A. E.

    2012-12-01

    by Cl-rich fluids [4]. The association of high-temperature carbonates with sulphides beneath the J-M reef supports the hydromagmatic theory which involves a late-stage chloride-carbonate fluid percolating upwards, dissolving PGE and sulphides and redepositing them at a higher stratigraphic level. [1] Anovitz, L.M., and Essene, E.J., 1987, Phase Equilibria in the System CaCO3-MgCO3-FeCO3: Journal of Petrology, v. 28, p. 389-414. [2] Hanley, J.J., Mungall, J.E., Pettke, T., Spooner, E.T.C., and Bray, C.J., 2008, Fluid and Halide Melt Inclusions of Magmatic Origin in the Ultramafic and Lower Banded Series, Stillwater Complex, Montana, USA: Journal of Petrology, v. 49, p. 1133-1160. [3] Boudreau, A.E., and McCallum, I.S., 1989, Investigations of the Stillwater Complex: Part V. Apatites as indicators of evolving fluid composition: Contributions to Mineralogy and Petrology, v. 102, p. 138-153. [4] Newton, R.C., and Manning, C.E., 2002, Experimental determination of calcite solubility in H2O-NaCl solutions at deep crust/upper mantle pressures and temperature: implications for metasomatic processes in shear zones: American Mineralogist, v. 87, p. 1401-1409.

  4. Multivariate study of trace element distribution in the geological record of Roñanzas Peat Bog (Asturias, N. Spain). Paleoenvironmental evolution and human activities over the last 8000 calyr BP.

    Science.gov (United States)

    Gallego, José Luis R; Ortiz, José E; Sierra, Carlos; Torres, Trinidad; Llamas, J F

    2013-06-01

    Trace element concentrations in the Roñanzas peat bog record reveal a contribution of natural processes but the influence of anthropogenic factors predominates in the last two millenniums, particularly aerosol deposition linked to mining and industrial activities in northern Spain. We observed that the Roñanzas record can be considered a preserved environment, suitable to search for local (major elements. Our study design represents a novel approach to assign natural vs. human contributions in peatlands. Therefore, synergies obtained by the simultaneous study of multivariate statistics and enrichment factors allow robust conclusions about paleoenvironmental evolution and human activities. Anthropogenic influence has also been reported in similar records in other parts of Europe, thereby suggesting large-scale sources for atmospheric pollution. However, here we revealed remarkable particularities, such as the association of Cd, Zn and Pb, mainly linked to regional and local factors (mining and more recently the metallurgical industry), whereas we propose that the occurrence of Hg is associated with a combination of regional factors and global atmospheric pollution. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Licensing the ACR-700 in the USA

    International Nuclear Information System (INIS)

    Langman, V.; Ion, R.; Reid, C.; Snell, V.

    2003-01-01

    Atomic Energy of Canada Ltd. (AECL), via its 100% owned US subsidiary AECL Technologies Inc., is performing a pre-application review of the Advanced CANDU Reactor (ACR) with the US Nuclear Regulatory Commission (USNRC). Completion of this pre-application review by mid-2004, is in support of an application to the USNRC for Standard Design Certification that is targeted for the fall of 2004. The intent of the pre-application review is to deal up-front with potential issues associated with the CANDU reactor genealogy of the ACR that are different from the Light Water Reactor (LWR) and Boiling Water Reactor (BWR) regulatory framework in the USA. The focus of the paper will be to describe the pre-application review process currently underway with the NRC staff. In the context of the pre-application review this paper will provide an overview of the licensing approach being used to introduce the ACR-700 to the USA. (author)

  6. Licensing the ACR-700 in the USA

    Energy Technology Data Exchange (ETDEWEB)

    Langman, V.; Ion, R. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada); Reid, C. [Bechtel Power Corporation, San Fransisco, California (United States); Snell, V. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada)

    2003-07-01

    Atomic Energy of Canada Ltd. (AECL), via its 100% owned US subsidiary AECL Technologies Inc., is performing a pre-application review of the Advanced CANDU Reactor (ACR) with the US Nuclear Regulatory Commission (USNRC). Completion of this pre-application review by mid-2004, is in support of an application to the USNRC for Standard Design Certification that is targeted for the fall of 2004. The intent of the pre-application review is to deal up-front with potential issues associated with the CANDU reactor genealogy of the ACR that are different from the Light Water Reactor (LWR) and Boiling Water Reactor (BWR) regulatory framework in the USA. The focus of the paper will be to describe the pre-application review process currently underway with the NRC staff. In the context of the pre-application review this paper will provide an overview of the licensing approach being used to introduce the ACR-700 to the USA. (author)

  7. Nuclear power in Japan and the USA

    International Nuclear Information System (INIS)

    Titterton, E.

    1979-06-01

    The development of the nuclear power industry in Japan and the USA is discussed. The author lists the number of nuclear power plants operating, under construction and planned and considers the contribution made by nuclear power stations to the total electricity generated. The advantages of nuclear power to both countries are outlined and forecasts are made of the role to be played by nuclear power in future years

  8. USA asepresident vihastas Venemaad / Erkki Bahovski

    Index Scriptorium Estoniae

    Bahovski, Erkki, 1970-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke 15. mai lk. 9. Läänemere ja Musta mere piirkonna riikide tippkohtumisel Vilniuses esinenud USA asepresident Dick Cheney märkis, et Ameerikal ja Euroopal on raske näha Venemaad demokraatlike riikide seas, kuna reformivastased püüavad Venemaal hävitada möödunud kümnendi edusamme. Vt. samas: Eesti pakub abiks oma kogemusi

  9. Utility procurement policies in the USA

    International Nuclear Information System (INIS)

    Lurf, G.; Nikazmerad, N.M.

    1983-01-01

    The subject is discussed under the headings: introduction; market history (historical uranium demand and production in the USA); recent long-term contract activity (expected US reactor demand and uranium production; expected US reactor demand and contracted uranium supplies); utility procurement attitudes; impact of inventories on procurement; current regulatory environment (spot-market price vs average long-term contract price); embargo and imports; conclusion. (U.K.)

  10. Revival of coal. [France and USA

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    This edition is devoted to the production and consumption of coal in France. It presents a study of the main topics involved, discusses the position of coal in France - under what form should it beused, and deals with coal consumption in cement works role of coal for urban district heating, future of coal gasification in France, France's coal policy, coal industry in the USA, underground gasification of coal, France's coal reserves, etc.. (In French)

  11. Burial and exhumation history of southern Sweden estimated from apatite fission-track data, stratigraphic landform analysis and the geological record

    Science.gov (United States)

    Japsen, Peter; Green, Paul F.; Lidmar-Bergström, Karna; Bonow, Johan M.; Erlström, Mikael

    2014-05-01

    We present new apatite fission-track analysis (AFTA) data from 87 samples of basement and sediment from southern Sweden, including samples from a 1.7 km deep borehole. The new AFTA data allow us to confirm the development of the South Swedish Dome as inferred from stratigraphic landform analysis (e.g. Lidmar-Bergström et al., 2013) and also to define the timing and magnitude of the events of burial and exhumation that shaped this prominent feature. Southern Sweden underwent a complex Palaeozoic - early Triassic history of burial and exhumation, but after a mid-Triassic event of uplift and exhumation, rocks on the Sub-Cambrian Peneplain cooled from palaeotemperatures ≥100°C. This event, that also affected southern Norway, West and East Greenland, marks an important phase in the breakup of Pangea. A second, regional phase of cooling and exhumation affected the area in the mid-Jurassic and eventually lead to stripping of the basement along the western and southern flanks of the South Swedish Dome prior to Late Cretaceous subsidence and burial and thus to formation of the sub-Cretaceous hilly relief. This event affected much of NW Europe as well as West and East Greenland, and it is coeval with the initial opening of the central Atlantic. A third, regional phase of cooling and exhumation from palaeotemperatures of 50-60°C took place in the Miocene and lead to the formation of the South Småland Peneplain. This phase affected southern Scandinavia but has no counterpart in Greenland. A final uplift phase that raised the South Småland Peneplain to its present elevation and lead to re-exposure of sub-Cretaceous hilly relief is not resolved in the AFTA data. The results underline the importance of epeirogenic movements (both uplift and subsidence) in regions that are often considered as stable cratons (cf. Green et al., 2013). Green, P.F., Lidmar-Bergström, K., Japsen, P., Bonow, J.M., Chalmers, J.A., 2013. Stratigraphic landscape analysis, thermochronology and the

  12. Syndepositional tectonics recorded by soft-sediment deformation and liquefaction structures (continental Lower Permian sediments, Southern Alps, Northern Italy): Stratigraphic significance

    Science.gov (United States)

    Berra, F.; Felletti, F.

    2011-04-01

    The Lower Permian succession of the Central Southern Alps (Lombardy, Northern Italy) was deposited in fault-controlled continental basins, probably related to transtensional tectonics. We focussed our study on the stratigraphic record of the Lower Permian Orobic Basin, which consists of a 1000 m thick succession of prevailing continental clastics with intercalations of ignimbritic flows and tuffs (Pizzo del Diavolo Formation, PDV) resting on the underlying prevailing pyroclastic flows of the Cabianca Volcanite. The PDV consists of a lower part (composed of conglomerates passing laterally to sandstones and distally to silt and shales), a middle part (pelitic, with carbonates) and an upper part (alternating sandstone, silt and volcanic flows). Syndepositional tectonics during the deposition of the PDV is recorded by facies distribution, thickness changes and by the presence of deformation and liquefaction structures interpreted as seismites. Deformation is recorded by both ductile structures (ball-and-pillow, plastic intrusion, disturbed lamination, convolute stratification and slumps) and brittle structures (sand dykes and autoclastic breccias). Both the sedimentological features and the geodynamic setting of the depositional basin confidently support the interpretation of the described deformation features as related to seismic shocks. The most significant seismically-induced deformation is represented by a slumped horizon (about 4 m thick on average) which can be followed laterally for more than 5 km. The slumped bed consists of playa-lake deposits (alternating pelites and microbial carbonates, associated with mud cracks and vertebrate tracks). The lateral continuity and the evidence of deposition on a very low-angle surface along with the deformation/liquefaction of the sediments suggest that the slump was triggered by a high-magnitude earthquake. The stratigraphic distribution of the seismites allows us to identify time intervals of intense seismic activity

  13. Maestrichtian benthic foraminifers from Ocean Point, North Slope, Alaska ( USA).

    Science.gov (United States)

    McDougall, K.

    1987-01-01

    Previous studies of fauna and flora from Ocean Point, Alaska, have suggested ages ranging from Campanian to early Eocene and that these assemblages are either highly endemic or commonplace. I demonstrate that the moderately abundant benthic foraminifers constitute early Maestrichtian boreal assemblages common to Canada and northern Europe. Paleoenvironmental analysis indicates that deposition took place in outer neritic settings (50 to 150m). The Ocean Point benthic foraminiferal assemblages contain species that migrated from the US Gulf Coast, North American Interior and Europe during the Campanian, and from Europe during the Maestrichtian. These faunal affinities suggest that seaways connected the Arctic to the North American Interior and Atlantic during the Campanian and that a shallow seaway connected the Arctic to the Atlantic during the early Maestrichtian. - from Author

  14. Stratigraphic Reconstruction of a Late Pleistocene Cypress Forest Discovered on the Northern Gulf of Mexico Continental Shelf

    Science.gov (United States)

    Gonzalez Rodriguez, S. M.; Bentley, S. J.; Obelcz, J.; Truong, J. T.; DeLong, K. L.; Xu, K.; Harley, G. L.; Reese, C. A.; Caporaso, A.; Shen, Z.

    2017-12-01

    A previously buried bald cypress forest (Taxodium distichum) was discovered on the continental shelf, offshore of Orange Beach, Alabama, USA, in 20 m water depth. The forest was possibly exhumed by Hurricane Ivan in 2004, and is now exposed as stumps in life position in a trough located in the northern Gulf of Mexico continental shelf seafloor. We are investigating the local stratigraphy, paleo-landscape, and mode of forest preservation of this unique site. In August 2015 and July 2016, submersible vibracores (18 in total) were collected. Core analysis included: bulk density and imaging via Geotek multi sensor core logger, sediment grain size, structure, and organic content via loss-on-ignition. Selected samples have been dated using 14C and optically stimulated luminescence (OSL) methods. Multibeam and CHIRP subbottom bathymetry provide context for litho- and chrono-stratigraphy of the site. Integration of core lithostratigraphy and modern shelf bathymetry reveal Holocene transgressive sands blanketing diverse sedimentary facies that are truncated by the late Pleistocene-early Holocene ravinement. Deposits below the ravinement surface include interbedded sand and mud (exact age unknown, but possibly pertaining to a shallow marine environment), overlying a floodplain/swamp facies of woody debris, peat, and mud (provisionally dated by 14C to 41-45 ka). These units grade laterally into paleosols that appear to be 10-15 ka older, based on recently obtained preliminary OSL dates. Occurrence of paleosols and swamp deposits of broadly similar age and elevation suggests that the ancient landscape possessed topographic relief that allowed wetland and upland habitats to develop in close proximity. These new OSL dates enhance our initial hypothesis that floodplain aggradation in the area was a key factor that might have allowed forest preservation. The timing of temporary sea level rises (SLR) ca. 40 and 60 ka. with our 14C and preliminary OSL dates, suggests that floodplain

  15. Origin of the Squantum 'Tillite', Massachusetts, USA: Modern Analogs and Implications for Neoproterozoic Climate Models

    Science.gov (United States)

    Carto, S. L.; Eyles, N.

    2009-05-01

    A central challenge to the 'Snowball Earth' hypothesis is whether the sedimentary rocks deposited during the Neoproterozoic (c. 750-570 Ma) are glacial tillites that accumulated under global ice sheets during this era. This uncertainty stems from the fact that diamictites are not uniquely glacial in origin, as the slumping and mixing of sediment downslope can also produce diamictites. A key deposit in this debate is the Squantum 'tillite' (ca. 595-570 Ma) preserved in the Boston Basin in Massachusetts, USA, which originated as an arc- related basin within the Avalon island arc terrane during the Neoproterozoic. Detailed field examinations of the Squantum by the author suggest that it owes its origin to the downslope transport of large volumes of unstable volcanic and sedimentary debris from steep basin margin slopes. No evidence of a glacial environment was identified. Thin-section analysis of this deposit has revealed a significant volcanic influence on sedimentation in the form of hitherto unrecognized volcanic lapilli tuff horizons and turbidites consisting of reworked ash in strata associated with Squantum diamictite. These results point to deposition related to tectonic activity and basin development rather than severe global glacial conditions. In light of these results, the Squantum diamictite was compared to the volcaniclastic mass flows deposits exposed along the active Lesser Antilles Arc in the Caribbean. Many of these flows are transported into the adjacent Grenada back-arc Basin by debris flows and turbidity currents resulting in the deposition of volcaniclastic conglomerates, diamictites and thin ash turbidites. Gross stratigraphic and sedimentological similarities of the mass flow facies in the Caribbean can be identified with the Squantum deposits, suggesting that appropriate depositional analogs for the Squantum can be found along the Lesser Antilles Arc. The significance of these results is that they emphasize the importance of detailed field

  16. Late Devonian spermatophyte diversity and paleoecology at Red Hill, north-central Pennsylvania, USA

    Energy Technology Data Exchange (ETDEWEB)

    Cressler, Walter L. III. [Francis Harvey Green Library, 29 West Rosedale Avenue, West Chester University, West Chester, PA, 19383 (United States); Prestianni, Cyrille [Universite de Liege, Boulevard du Rectorat B18, Liege 4000 (Belgium); LePage, Ben A. [The Academy of Natural Sciences, 1900 Benjamin Franklin Parkway, Philadelphia, PA, 19103 and PECO Energy Company, 2301 Market Avenue, S9-1, Philadelphia, PA 19103 (United States)

    2010-08-01

    Early spermatophytes have been discovered at Red Hill, a Late Devonian (Famennian) fossil locality in north-central Pennsylvania, USA. The Red Hill locality contains an Archaeopteris-dominated flora within an outcrop of the Duncannon Member of the Catskill Formation. Palynological analyses of the plant fossil-bearing horizons within the Red Hill outcrop indicate deposition within the VCo palynozone. This is the earliest time horizon known to contain evidence for spermatophytes, and is contemporaneous with well-known spermatophyte-bearing deposits in West Virginia and Belgium. Some of the spermatophyte material from Red Hill compares well with Aglosperma sp., previously known as isolated ovules from the latest Devonian of South Wales and England, thus extending its geographic and stratigraphic range. Red Hill specimens of Aglosperma sp. occur both as isolated ovules and attached to dichotomously forking axes. Additional spermatophyte cupules discovered at Red Hill are morphologically similar to those of the previously described Late Devonian spermatophytes Elkinsia Rothwell, Scheckler, et Gillespie, Moresnetia Stockmans, and Xenotheca Arber et Goode. Some of the Red Hill cupule complexes are distinct from the aforementioned taxa in consisting of slender dichotomously forking axes terminating in paired cupules with highly fused and symmetric cupule quadrant lobes. The distinctive nature of these Red Hill specimens warrants the creation of Duodimidia pfefferkornii Cressler, Prestianni, et LePage gen. et sp. nov. Plant fossil remains with sphenopteroid foliage are also present at Red Hill, possibly attributable to the spermatophytes. Previous systematic sampling of the rich plant-fossil bearing layer at Red Hill and analysis of its floristic diversity and abundance as well as the presence and absence of charcoal suggests a pattern of floral turnover from a local-scale Rhacophyton-dominated community to spermatophyte colonization following disturbance by wildfires

  17. New insights into structural and stratigraphic aspects of central Northern Switzerland from the Nagra 2D reflection seismic campaign 2011/12

    International Nuclear Information System (INIS)

    Meier, B.

    2015-01-01

    In this article, some findings resulting from the interpretation of reprocessed and newly acquired 2D seismic data in the central Northern Switzerland are presented. The seismic examples illustrate the relationship between basement and cover-tectonics and offer a closer look at seismic-stratigraphic characteristics which can be observed in the Middle Jurassic sequence. The new 2D seismic data have closed an important data gaps between the Nagra siting regions 'Jura Ost' and Nördlich Lägern' proposed for radioactive waste disposal and allow clarification of the general structural framework and internal composition of the Permo-Carboniferous Through. Furthermore, the kinematic relationships between the basement and cover structures can be studied and the newly acquired seismic data have allowed detailed depositional structures and seismic facies changes within the Mid-Upper Dogger sequence to be recognized, particularly east and west of the lower Aare valley. (author)

  18. Pseudoclypeina? crnogorica Radoičić, 1972: Stratigraphic revision and taxonomic note on a little known dasycladalean alga from Montenegro

    Directory of Open Access Journals (Sweden)

    Radoičić Rajka

    2013-01-01

    Full Text Available Pseudoclypeina? crnogorica was first described in 1972 from the Lower, Cretaceous limestone of the Njegoš Mt. area, Montenegro, Dinaric Carbonate Platform. It differs from other species of the genus Pseudoclypeina by its calcification pattern, the shape and relative length of the first and second order laterals, and by the presence in the type-material (a thin section containing the holotype of sections standing for the sterile portion of the thallus. This is why in this paper, the generic name is left in open nomenclature. On this occasion the species, whose presence is also reported from southern Iran, is re-described and better illustrated, based on material originating from other outcrops in Montenegro. The stratigraphic position is reviewed as well. Pseudoclypeina? crnogorica occurs in shallow water inner platform facies of early Neocomian age, along with Selliporella neocomiensis.

  19. Facies-succession and architecture of the third-order sequences and their stratigraphic framework of the Devonian in Yunnan-Guizhou-Guangxi area, South China

    Directory of Open Access Journals (Sweden)

    Mei Mingxiang

    2013-01-01

    Full Text Available The Caledonian orogeny at the end of the Silurian resulted in great changes in the palaeogeography in the Yunnan-Guizhou-Guangxi area of South China; the continental area of the Early Paleozoic evolved into the extensive Dian-Qian-Gui Sea in the Late Paleozoic. Early in the Devonian, as a result of a major transgression, seawater encroached gradually from the south to the north and clastic facies were deposited. Carbonate deposition was then established in the Yunnan-Guizhou-Guangxi area, with a palaeogeography marked by attached platforms, isolated platforms and narrow basins. As a result of the Ziyun movement towards the end of the Devonian, the Upper Devonian strata are regressive and thin out from the open-sea to the land areas. A study of the nature and distribution of sedimentary facies in space and time recognises 13 third-order sequences in the Devonian strata in Yunnan-Guizhou-Guangxi area, and these form two second-order sequences. The strata of the Lower Devonian comprise 5 third-order sequences (SQ1 to SQ5, which are dominated by transgressive clastics. 4 third-order sequences (SQ6 to SQ9 in the Middle Devonian are characterized by alternations of transgressive clastics and highstand carbonates. In the Upper Devonian, carbonates constitute 4 third-order sequences (SQ10 to SQ13, which are generally marked by the transgressive limestones and highstand dolomites. On the basis of earlier biostratigraphic studies, sea-level changes represented by the third-order sequences with their different facies successions are explored, and the sequence stratigraphic framework is established. Therefore, the Devonian strata in the study area provide an example for further understanding of depositional trends within the sequence-stratigraphic framework.

  20. Stratal Control Volumes and Stratal Control Trajectories: A New Method to Constrain, Understand and Reconcile Results from Stratigraphic Outcrop Analysis, Subsurface Analysis and Analogue and Numerical Modelling

    Science.gov (United States)

    Burgess, P. M.; Steel, R. J.

    2016-12-01

    Decoding a history of Earth's surface dynamics from strata requires robust quantitative understanding of supply and accommodation controls. The concept of stratigraphic solution sets has proven useful in this decoding, but application and development of this approach has so far been surprisingly limited. Stratal control volumes, areas and trajectories are new approaches defined here, building on previous ideas about stratigraphic solution sets, to help analyse and understand the sedimentary record of Earth surface dynamics. They may have particular application reconciling results from outcrop and subsurface analysis with results from analogue and numerical experiments. Stratal control volumes are sets of points in a three-dimensional volume, with axes of subsidence, sediment supply and eustatic rates of change, populated with probabilities derived from analysis of subsidence, supply and eustasy timeseries (Figure 1). These empirical probabilities indicate the likelihood of occurrence of any particular combination of control rates defined by any point in the volume. The stratal control volume can then by analysed to determine which parts of the volume represent relative sea-level fall and rise, where in the volume particular stacking patterns will occur, and how probable those stacking patterns are. For outcrop and subsurface analysis, using a stratal control area with eustasy and subsidence combined on a relative sea-level axis allows similar analysis, and may be preferable. A stratal control trajectory is a history of supply and accommodation creation rates, interpreted from outcrop or subsurface data, or observed in analogue and numerical experiments, and plotted as a series of linked points forming a trajectory through the stratal control volume (Figure 1) or area. Three examples are presented, one from outcrop and two theoretical. Much work remains to be done to build a properly representative database of stratal controls, but careful comparison of stratal

  1. Holocene alluvial stratigraphy and response to climate change in the Roaring River valley, Front Range, Colorado, USA

    Science.gov (United States)

    Madole, Richard F.

    2012-09-01

    Stratigraphic analyses and radiocarbon geochronology of alluvial deposits exposed along the Roaring River, Colorado, lead to three principal conclusions: (1) the opinion that stream channels in the higher parts of the Front Range are relics of the Pleistocene and nonalluvial under the present climate, as argued in a water-rights trial USA v. Colorado, is untenable, (2) beds of clast-supported gravel alternate in vertical succession with beds of fine-grained sediment (sand, mud, and peat) in response to centennial-scale changes in snowmelt-driven peak discharges, and (3) alluvial strata provide information about Holocene climate history that complements the history provided by cirque moraines, periglacial deposits, and paleontological data. Most alluvial strata are of late Holocene age and record, among other things, that: (1) the largest peak flows since the end of the Pleistocene occurred during the late Holocene; (2) the occurrence of a mid- to late Holocene interval (~ 2450-1630(?) cal yr BP) of warmer climate, which is not clearly identified in palynological records; and (3) the Little Ice Age climate seems to have had little impact on stream channels, except perhaps for minor (~ 1 m) incision.

  2. USA erisaadik : USA investorid Eestis rahul / J. Frank Mermoud ; interv. Sirje Rank

    Index Scriptorium Estoniae

    Mermoud, J. Frank

    2004-01-01

    Ameerika Ühendriikide välisministri nõunik ja erisaadik majandusküsimustes kiidab Eesti edu, räägib USA investorite rahuolust Eesti majanduskeskkonnaga ja väljendab muret Euroopa Liidu kavade pärast maksude ühtlustamiseks

  3. The birth and growth of neuroradiology in the USA

    International Nuclear Information System (INIS)

    Gutierrez, C.; Goettingen Univ. Germany, F.R. Klinik fuer Neurochirurgie)

    1981-01-01

    Neuroradiology in the USA was started by the neurosurgeons Harvey Cushing, who personally made the first X-rays used to treat a patient with a neurological disability, and Walter Dandy, who first performed air ventriculography, ventriculoscopy, air encephalography and air myelography. The father of neuroradiology in the USA was Merrill Sosman, Cushing's associate. Modern neuroradiology was introduced into the USA from Europe by Mannie Schechter who was one of the original team of three Chief Editors of Neuroradiology. (orig.)

  4. USA relvastab araabia maid miljardite dollaritega / Kunnar Kukk

    Index Scriptorium Estoniae

    Kukk, Kunnar

    2007-01-01

    USA välisminister Condoleezza Rice ja kaitseminister Robert Gates tegid visiidi Saudi-Araabiasse. Arvatakse, et nad on pehmendamas katastroofi, mis järgneks USA vägede järk-järgulisele taandumisele Iraagist. USA kavatseb anda Pärsia riikidele sõjalist abi, et tuua Iraan kolmepoolsetele läbirääkimistele. Lisa: Kodusõda võib olla vältimatu

  5. Short history of PACS. Part I: USA

    International Nuclear Information System (INIS)

    Huang, H.K.

    2011-01-01

    This historical review covers the PACS development in the USA during the past 28 years from 1982 to 2010. General historical remarks of PACS and international scene in three stages from infancy, puberty to adolescence are presented. Early PACS development was mostly financed by the federal government including the National Institutes of Health (NIH) and the U.S. Army Medical Research and Materiel Command. PACS evolution went through several stages. The earliest stages included the definition of large-scale PACS, establishment of the DICOM and other standards, the development of some early key PACS related technologies, and PACS implementation strategies. The later stages were in the concept of enterprise PACS, IHE (Integrating the Healthcare Enterprise) workflow profiles, and ePR with image distribution. The current most excited accomplishment is in the development of the new field in medical imaging informatics. This review goes through these stages and events in the USA during these 28 years, whenever an event involved participants from other countries, the contributors are cited.

  6. Short history of PACS. Part I: USA.

    Science.gov (United States)

    Huang, H K

    2011-05-01

    This historical review covers the PACS development in the USA during the past 28 years from 1982 to 2010. General historical remarks of PACS and international scene in three stages from infancy, puberty to adolescence are presented. Early PACS development was mostly financed by the federal government including the National Institutes of Health (NIH) and the U.S. Army Medical Research and Materiel Command. PACS evolution went through several stages. The earliest stages included the definition of large-scale PACS, establishment of the DICOM and other standards, the development of some early key PACS related technologies, and PACS implementation strategies. The later stages were in the concept of enterprise PACS, IHE (Integrating the Healthcare Enterprise) workflow profiles, and ePR with image distribution. The current most excited accomplishment is in the development of the new field in medical imaging informatics. This review goes through these stages and events in the USA during these 28 years, whenever an event involved participants from other countries, the contributors are cited. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  7. Overview of the USA inertial fusion program

    International Nuclear Information System (INIS)

    Kahalas, S.L.

    1989-01-01

    The next step in the USA inertial fusion program is to begin planning for a Laboratory Microfusion Facility or LMF. The LMF would have an output energy of between 200 and 1000 MJ, the latter energy being equivalent to a quarter ton of high explosive, with an input driver energy of 5-10 MJ. This implies a high target gain, 100-200 or more, with either a laser or particle beam driver. The LMF would cost a half billion to a billion dollars and would require a serious commitment by the country and the Department of Energy. The Department is in the stage of preliminary planning for an LMF and beginning a process by which a driver selection can be made in the fiscal year 1991-1992 timeframe. Construction initiation will require that a departmental decision be made as well as appropriation of funds within the Congressional funding cycle. In this paper, we review recent progress leading to the new USA program planning for the next facility and describe the status of this preliminary planning as well as characteristics of the LMF. (orig.)

  8. Short history of PACS. Part I: USA

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.K., E-mail: hkhuang@aol.com [Departments of Radiology and Biomedical Engineering, University of Southern California (United States); Hong Kong Polytechnic University (Hong Kong); Shanghai Institute of Technical Physics, Chinese Academy of Sciences (China)

    2011-05-15

    This historical review covers the PACS development in the USA during the past 28 years from 1982 to 2010. General historical remarks of PACS and international scene in three stages from infancy, puberty to adolescence are presented. Early PACS development was mostly financed by the federal government including the National Institutes of Health (NIH) and the U.S. Army Medical Research and Materiel Command. PACS evolution went through several stages. The earliest stages included the definition of large-scale PACS, establishment of the DICOM and other standards, the development of some early key PACS related technologies, and PACS implementation strategies. The later stages were in the concept of enterprise PACS, IHE (Integrating the Healthcare Enterprise) workflow profiles, and ePR with image distribution. The current most excited accomplishment is in the development of the new field in medical imaging informatics. This review goes through these stages and events in the USA during these 28 years, whenever an event involved participants from other countries, the contributors are cited.

  9. Läbikatsumine USA lennujaamades riivab siin tehtavast vähem / Raimo Poom

    Index Scriptorium Estoniae

    Poom, Raimo

    2010-01-01

    USA sisejulgeoleku ministeeriumi privaatsuse ja andmekaitse juht Mary Ellen Callahan kinnitab, et USA-sse reisivate inimeste krediitkaardiandmeid kasutatakse vaid elektroonilise reisi autoriseerimise süsteemi jaoks ning andmeid säilitab USA rahandusministeerium. Ta on arvamusel, et USA-s on kehaskannerite kasutamisel reisija privaatsuse kaitse parem kui Euroopas

  10. Refining the timing of the MIS 5e signal, West Caicos, Bristish West Indies:implications for paleoclimatic interpretation of the stratigraphic record

    Science.gov (United States)

    Kerans, C.; Zahm, C.; Bachtel, S.; Hearty, P.; Cheng, H.

    2017-12-01

    The progressive refinement of the Last Interglacial (LIG) tropical carbonate record has focused attention on the dramatically abrupt and episodic nature of this critical approximate 12 ka time window. From initial carbonate platform flooding at 133 ka to rapid sea level fall and exposure at 118 ka, the majority of present-day Bahamian and Caribbean strata were produced in a remarkably similar pattern extending from Bermuda and the Bahamas through the Cayman Islands, Yucatan, and south to the Dominican Republic. The position of coral reefs and oolitic sands of the LIG to a first order fit the global insolation-driven climate warming signal. Less well accepted/resolved is the existence of two distinct SL peaks with an intervening sea level fall implying a non-orbitally forced climate shift during this broader highstand. West Caicos, a 10 x 5 km leeward island on the Caicos Platform is an excellent example of LIG carbonate stratigraphic complexity. We collected sub-meter-resolution whole-island airborn LIDAR and decimeter-resolution UAV-constructed DEM's of the western and southern coastal outcrops to serve as a base for decimeter-scale mapping of the MIS 11, 7?, 5e, and Holocene units of the island, with particular focus on the continuous 8.4 km west coast outcrop of the MIS 5e. Seventy-five AAR relative age assignments from ooid separates, pinned by 16 U/Th dates from corals coming from MIS stage 11, lower MIS 5e, and upper MIS 5e reefs helped establish the age model for the Pleistocene-Holocene stratigraphy. The lower MIS 5e reef system averages 128 ka with an onset age of 133 ka. Upper MIS 5e corals ranges from 123 ka to 116 ka, bracketing the intra-MIS 5e sea-level fall between to approximately 125 ka. The intra-MIS 5e fall is a distinct erosional unconformity across 5 km of continuous outcrop, truncating the upper 2.5 m of lower 5e reef. The complexity of MIS 5e record on West Caicos and in the Northern Atlantic and Caribbean platforms regionally provides

  11. Impact of the AD 79 explosive eruption on Pompeii, II. Causes of death of the inhabitants inferred by stratigraphic analysis and areal distribution of the human casualties

    Science.gov (United States)

    Luongo, Giuseppe; Perrotta, Annamaria; Scarpati, Claudio; De Carolis, Ernesto; Patricelli, Giovanni; Ciarallo, Annamaria

    2003-08-01

    Detailed descriptions of the effects of explosive eruptions on urban settlements available to volcanologists are relatively rare. Apart from disease and starvation, the largest number of human deaths caused by explosive eruptions in the twentieth century are due to pyroclastic flows. The relationship between the number of victims related to a specific hazard and the presence of urban settlements in the area covered by the eruption has been shown. However, pyroclastic falls are also extremely dangerous under certain conditions. These conclusions are based on archaeological and volcanological studies carried out on the victims of the well-known AD 79 eruption of Vesuvius that destroyed and buried the Roman city of Pompeii. The stratigraphic level in the pyroclastic deposit and the location of all the casualties found are described and discussed. The total number of victims recovered during the archaeological excavations amounts to 1150. Of these, 1044 well recognisable bodies plus an additional group of 100 individuals were identified based on the analysis of several groups of scattered bones. Of the former, 394 were found in the lower pumice lapilli fall deposit and 650 in the upper stratified ash and pumice lapilli pyroclastic density currents (PDCs) deposits. In addition, a tentative evaluation suggests that 464 corpses may still be buried in the unexcavated part of the city. According to the reconstruction presented in this paper, during the first phase of the eruption (August 24, AD 79) a huge quantity of pumice lapilli fell on Pompeii burying the city under 3 m of pyroclastic material. During this eruptive phase, most of the inhabitants managed to leave the city. However, 38% of the known victims were killed during this phase mainly as a consequence of roofs and walls collapsing under the increasing weight of the pumice lapilli deposit. During the second phase of the eruption (August 25, AD 79) 49% of the total victims were on the roadways and 51% inside

  12. Structural and stratigraphic constraints on tsunamigenic rupture along the frontal Sunda megathrust from MegaTera bathymetric and seismic reflection data

    Science.gov (United States)

    Bradley, K. E.; Qin, Y.; Villanueva-Robles, F.; Hananto, N.; Leclerc, F.; Singh, S. C.; Tapponnier, P.; Sieh, K.; Wei, S.; Carton, H. D.; Permana, H.; Avianto, P.; Nugroho, A. B.

    2017-12-01

    The joint EOS/IPG/LIPI 2015 MegaTera expedition collected high-resolution seismic reflection profiles and bathymetric data across the Sunda trench, updip of the Mw7.7, 2010 Mentawai tsunami-earthquake rupture patch. These data reveal rapid lateral variations in both the stratigraphic level of the frontal Sunda megathrust and the vergence of frontal ramp faults. The stratigraphic depth of the megathrust at the deformation front correlates with ramp-thrust vergence and with changes in the basal friction angle inferred by critical-taper wedge theory. Where ramp thrusts verge uniformly seaward and have an average dip of 30°, the megathrust decollement resides atop a high-amplitude reflector that marks the inferred top of pelagic sediments. Where ramp thrusts are bi-vergent (similar throw on both landward- and seaward-vergent faults) and have an average dip of 42°, the decollement is higher, within the incoming clastic sequence, above a seismically transparent unit inferred to represent distal fan muds. Where ramp thrusts are uniformly landward vergent, the decollement sits directly on top of the oceanic crust that forms the bathymetrically prominent, subducting Investigator Ridge. The two, separate regions of large tsunamigenic ground-surface uplift during the 2010 tsunami earthquake that have been inferred from joint inversions of seismic, GPS, and tsunami data (e.g. Yue et al., 2014; Satake et al., 2013) correspond to the areas of frontal bi-vergence in the MegaTera data. We propose that enhanced surface uplift and tsunamigenesis during this event occurred when rupture propagated onto areas where the decollement sits directly above the basal muds of the incoming clastic sequence. Thus we hypothesize that frontal bi-vergence may mark areas of enhanced tsunami hazard posed by small magnitude, shallow megathrust ruptures that propagate to the trench. [Yue, H. et al., 2014, Rupture process of the…, JGR 119 doi:10.1002/2014JB011082; Satake, K. et al., 2013, Tsunami

  13. 3D seismic investigation of the structural and stratigraphic characteristics of the Pagasa Wedge, Southwest Palawan Basin, Philippines, and their tectonic implications

    Science.gov (United States)

    Ilao, Kimberly A.; Morley, Christopher K.; Aurelio, Mario A.

    2018-04-01

    The Pagasa Wedge is a poorly imaged deepwater orogenic wedge that has been variously interpreted as representing an accretionary prism, a former accretionary prism modified by thrusting onto a thinned continental margin, and a gravity-driven fold-thrust belt. This study, using 2D and 3D seismic data, together with well information indicates that at least the external part of the wedge is dominantly composed of mass transport complexes, capped by syn-kinematic sediments that have thrusts and normal faults superimposed upon them. Drilling shows that despite stratigraphic repetition of Eocene Middle Miocene units, there is stratigraphic omission of Oligocene and Early Miocene units. This absence suggests that mass transport processes have introduced the Eocene section into the wedge rather than tectonic thrusting. The accretionary prism stage (Oligocene) of the Central Palawan Ophiolite history appears to be marked by predominantly north-vergent deformation. The Deep Regional Unconformity (∼17 Ma) likely indicates the approximate time when obduction ceased in Palawan. The Pagasa Wedge is a late-stage product of the convergence history that was active in its final phase sometime above the top of the Nido Limestone (∼16 Ma) and the base of the Tabon Limestone in the Aboabo-A1X well (∼9 Ma). The top of the wedge is traditionally associated with the Middle Miocene Unconformity (MMU), However the presence of multiple unconformities, diachronous formation tops, local tectonic unconformities and regional diachronous events (e.g. migrating forebulges) all suggest simply giving a single age (or assigning a single unconformity, such as the MMU as defining the top of the Pagasa Wedge is inappropriate. The overall NE-SW trend of the wedge, and the dominant NW transport of structures within the wedge diverge from the more northerly transport direction determined from outcrops in Palawan, and also from the Nido Limestone in the SW part of the Pagasa Wedge. Possibly this NW

  14. The Bero Volganic Group: New Lithological, Stratigraphic, and Geochemical Data of this Extension of the Parana-Etendeka Igneous Province into SW Angola with Implications

    Science.gov (United States)

    Marsh, J.; Swart, R.

    2015-12-01

    The Bero Volcanic Group, an extension of the Etendeka-Paraná Igneous Province into SW Angola, forms the eroded basement to the on-shore Namibe Basin, an Early Cretaceous-Cenozoic terrestrial and marine sedimentary sequence. The igneous suite outcrops between latitudes 14.68o and 15.25o S and comprises quartz latite rheoignimbrites/lavas, tholeiitic basaltic lavas, pyroclastic/volcaniclastic deposits, minor aeolian sandstones, and mafic tholeiitic dykes and gabbroic sheets. Quartz latite lithologies dominate. In the Rio Bero area in the S quartz latites are underlain by several thin flows of basalt interbedded with, and underlain by, thin discontinuous lenses of aeolian sandstone. This sequence is consistent with the general stratigraphic sequence in the northern Etendeka of Namibia. To the N basalts and aeolian sandstones are absent and the quartz latites lie directly on Precambrian basement rocks in places. To date, data for a quartz latite correlated with a Chapecó rhyolites of the Paraná are available from only one locality in Angola. This study's wider sampling and major and trace element and radiogenic isotope analysis reveals the following: (1) all mafic rocks are high-Ti, the lavas being equivalent to the Khumiba/Urubici type; (2) mafic dykes cutting the quartz latites having affinities to the Paranapanema-Ribeira mafic lavas; (3) five quartz latite geochemical types are present, three of which are known from Etendeka/Paraná (Sarusas/Guarapuava, Khoraseb/Ourinhos and Ventura) and their stratigraphic relationships in Angola are consistent with those in the Etendeka and Paraná; (4) their Angolan occurrence significantly extends the area covered by, and potential eruptive volumes of, these silicic types; (5) two other quartz latite types are unknown in the Etendeka and Paraná and are probably products of low-volume, local eruptions. The Chinguau type is geochemically similar to the low-Ti quartz lalites of the southern Etendeka but has lower Epsilon Nd

  15. USA üritab leida Teherani agente Iraagist / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2007-01-01

    USA süüdistab Iraani, et see abistab Iraagis mahdiste, mida juhib Muqtada al-Sadri. Autori sõnul on Iraani eliitüksuse Qudsi korpuse koostööd al-Sadriga aga sama vähe tõestatud kui omal ajal USA väidet Saddam Husseini ja al-Qaida vahel

  16. Ruslands betændte forhold til USA

    DEFF Research Database (Denmark)

    Skak, Mette

    2015-01-01

    Rusland udgør en anden stormagtsudfordring for USA. Rusland er en stormagt i forfald, som imidlertid har genopfundet sin gamle sovjetiske 'Manifest Destiny'.......Rusland udgør en anden stormagtsudfordring for USA. Rusland er en stormagt i forfald, som imidlertid har genopfundet sin gamle sovjetiske 'Manifest Destiny'....

  17. Oletus : USA luurevanglad on Poolas ja Rumeenias / Krister Paris

    Index Scriptorium Estoniae

    Paris, Krister, 1977-

    2005-01-01

    USA ajalehe Washington Post andmeil hoiab USA terrorismis kahtlustavaid Ida-Euroopa riikides. Poola ajalehe allikate väitel on üks neist riikidest Poola. Poola, Rumeenia, Bulgaaria tõrjuvad kahtlustusi, Tšehhi väitel on ameeriklaste palvele vange majutada ära öeldud

  18. USA kliimamuutuse vastu: Kopenhaagenis ja edaspidi / Michael C. Polt

    Index Scriptorium Estoniae

    Polt, Michael C., 1954-

    2009-01-01

    Käsitledes Kopenhaageni kliimakonverentsi, märgib USA Eesti-suursaadik, et USA on valmis paika panema eesmärgi vähendada kohalike seadustega kooskõlas 2020. aastaks kasvuhoonegaaside heitmete emissiooni tasemeni, mis oleks 17% väiksem 2005. aasta tasemest

  19. Valitsus vaeb USA viisavabadusenõudeid / Raimo Poom

    Index Scriptorium Estoniae

    Poom, Raimo

    2008-01-01

    USA viisavabaduse aluseks oleva vastastikuse mõistmise memorandumi projekt on täna valitsuse istungi päevakorras. Tšehhi ja USA on juba sõlminud kahepoolse memorandumi, mõnedel hinnangutel on Tšehhi järele andnud kogu ameeriklaste nõudmiste paketile. Lisa: Andmekaitsjad pole viimase seisuga kursis

  20. USA toetab Lähis-Ida konfliktides Iisraeli / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2006-01-01

    USA kasutas ÜRO Julgeolekunõukogus vetoõigust resolutsiooni suhtes, milles nõuti Iisraelilt Gaza sektoris toimuvate rünnakute kohest lõpetamist, USA ÜRO suursaadiku John Boltoni sõnul oleks dokumendi vastuvõtmine õõnestanud Julgeolekunõukogu usaldusväärsust

  1. Distribution, hosts and identification of Meloidogyne partityla in the USA

    Science.gov (United States)

    Pecan, Carya illinoensis, is an economically important nut crop and member of the Juglandaceae native to the southern USA. Discovered in South Africa in 1986, Meloidogyne partityla was first found infecting pecan in USA in 1996 and currently occurs in Texas, New Mexico, Georgia, Arizona, Oklahoma a...

  2. 77 FR 38039 - Corporation for Travel Promotion (dba Brand USA)

    Science.gov (United States)

    2012-06-26

    ... DEPARTMENT OF COMMERCE International Trade Administration Corporation for Travel Promotion (dba Brand USA) AGENCY: International Trade Administration, Commerce. ACTION: Notice of an opportunity for... Corporation for Travel Promotion (Board) (dba Brand USA). The purpose of the Board is to guide the Corporation...

  3. 78 FR 53728 - Corporation for Travel Promotion (dba Brand USA)

    Science.gov (United States)

    2013-08-30

    ... DEPARTMENT OF COMMERCE International Trade Administration Corporation for Travel Promotion (dba Brand USA) AGENCY: International Trade Administration, U.S. Department of Commerce. ACTION: Notice of an... the Corporation for Travel Promotion (dba Brand USA). The purpose of the Board is to guide the...

  4. 78 FR 44531 - Corporation for Travel Promotion (dba Brand USA)

    Science.gov (United States)

    2013-07-24

    ... DEPARTMENT OF COMMERCE International Trade Administration Corporation for Travel Promotion (dba Brand USA) AGENCY: International Trade Administration, U.S. Department of Commerce. ACTION: Notice of an... the Corporation for Travel Promotion (dba Brand USA). The purpose of the Board is to guide the...

  5. FY2015 Analysis of the Teamwork USA Program. Memorandum

    Science.gov (United States)

    Howard, Mark

    2015-01-01

    The Department of Research and Evaluation (DRE) has completed an analysis of the performance of students who participated in the Teamwork USA Program, administered in FY2014 at three District schools. Teamwork USA hopes to improve student achievement at select Title I elementary schools via its Instrumental Music Program grant. This memorandum to…

  6. Tropical Trametes lactinea is widely distributed in the eastern USA

    Czech Academy of Sciences Publication Activity Database

    Vlasák, Josef; Kout, J.

    2011-01-01

    Roč. 115, č. 1 (2011), s. 271-279 ISSN 0093-4666 Institutional research plan: CEZ:AV0Z50510513 Keywords : Basidiomycota, USA new record, taxonomy * USA new record * taxonomy Subject RIV: EF - Botanics Impact factor: 0.709, year: 2011

  7. Nuclear reactor safety in the USA

    International Nuclear Information System (INIS)

    Vigil, J.C.

    1983-01-01

    Nuclear reactor safety in the USA has emphasized a defense-in-depth approach to protecting the public from reactor accidents. This approach was severely tested by the Three Mile Island accident and was found to be effective in safeguarding the public health and safety. However, the economic impact of the TMI accident was very large. Consequently, more attention is now being given to plant protection as well as public-health protection in reactor-safety studies. Sophisticated computer simulations at Los Alamos are making major contributions in this area. In terms of public risk, nuclear power plants compare favorably with other large-scale alternatives to electricity generation. Unfortunately, there is a large gulf between the real risks of nuclear power and the present public perception of these risks

  8. SAT for NPP personnel training in USA

    International Nuclear Information System (INIS)

    Spinney, R.

    1995-01-01

    This discussion addressed the experience with the application of SAT at USA NPPs. In particular, the transition of NPP training processes, staff composition, and reporting structure from the TMI accident to present. As well, oversight and guidance activities of the INPO and more intensive inspection by the NRC began during this period. The average NPP training staff grew to 30-40 per unit, along with a change in reporting line from plant to corporate management. With the reduction of resources occurring in the late 1980s, overall training staff size decreased, the composition changed, and reporting line reverted to plant management. The overall lessons-learned for application of the SAT consisted of the need for simplification, management involvement, and exploitation of the technology

  9. Report of a mission to the USA

    International Nuclear Information System (INIS)

    Valentin, A.

    1959-01-01

    As the personnel working with radioactive products is facing hazards due to irradiation and to contamination by absorption, glove boxes provide a sufficient protection against pure alpha and low beta or gamma emitters, but beta and gamma emitters such as irradiated uranium alloys require the protection by thick lead or concrete walls and handling alpha and gamma emitters (such as polonium, plutonium and uranium 233) requires alpha-tight and gamma-protective enclosures. In some cases, inert or semi-inert atmosphere are required. In this report, the author present and describe how these protections are provided or projected in installations visited in the USA (in Oak Ridge, Los Alamos, Brookhaven, and Argonne laboratories). They distinguish the conventional design of beta-gamma cells, the transformation of gamma cells into alpha-gamma cell, and different types of alpha-gamma cells (glove boxes in gamma enclosure, tight enclosure with possible staff entrance, tight enclosure with forbidden entrance)

  10. Snus use and rejection in the USA.

    Science.gov (United States)

    Biener, Lois; Roman, Anthony M; Mc Inerney, Scott A; Bolcic-Jankovic, Dragana; Hatsukami, Dororthy K; Loukas, Alexandra; O'Connor, Richard J; Romito, Laura

    2016-07-01

    To determine whether snus might become a strategy for reducing the harm associated with cigarette smoking in the USA as appears to be the case in Sweden, we examined receptivity to snus use in two cities with the greatest exposure to the major brands. A dual frame, telephone survey and a brief mail survey were conducted in 2011 and 2012 in Indianapolis, Indiana and Dallas/Fort Worth Texas. Over 5000 adults completed surveys. Trial, ever use, current use and reasons for using or quitting snus after trial were measured. Among male smokers, 29.9% had ever tried snus (CI 22.7 to 38.1) and 4.2% were current users (CI 1.6 to 10.7). Among female smokers, 8.5% ever tried snus (CI 4.4 to 15.7) and current use was unknown. Current use was virtually absent among former smokers and never smokers. A major predictor of any level of snus use was current use of conventional smokeless tobacco. Those who tried and gave up snus cited curiosity (41.3%) and the fact that it was available at low or no cost (30%) as reasons for trial; reasons for not continuing included preferring another form of tobacco (75.1%) and disliking the mouth feel (34.6%). Almost all current snus users indicated that they were trying to cut down on cigarettes, but few (3.9%) were using it to quit smoking entirely. The low rate of adoption of snus suggests that neither the hopes nor the fears surrounding this new product are likely to be realised in the USA with the current marketing patterns. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  11. Strontium-90 migration in Hanford sediments, USA

    International Nuclear Information System (INIS)

    Steefel, C.I.; Yang, L.; Carroll, S.A.; Roberts, S.; Zachara, J.M.; Yabusaki, S.B.

    2005-01-01

    Full text of publication follows: Strontium-90 is an important risk-driving contaminant at the Hanford site in eastern Washington, USA. Disposal operations at the Hanford 100-N area released millions of liters of reactor cooling water containing high concentrations of strontium-90 into the vadose zone immediately adjacent to the Columbia River. The effectiveness of pump-and-treat methods for remediation have been questioned, largely because the strontium is strongly sorbed on subsurface sediments via ion exchange reactions and co-precipitation in carbonates. In addition, groundwater monitoring wells show a fluctuating seasonal behavior in which high strontium-90 concentrations correlate with high Columbia River stage, even while average concentrations remain approximately constant. A series of fully saturated reactive transport column experiments have been conducted to investigate the important controls on strontium migration in Hanford groundwater [1]. The experiments were designed to investigate the multicomponent cation exchange behavior of strontium in competition with the cations Na + , Ca +2 , and Mg +2 , the concentration of which differs between river water and groundwater. Reactive transport modeling of the experiments indicates that the Sr +2 selectivity coefficient becomes larger with increasing NaNO 3 concentration, a behavior also shown by the divalent cations Ca +2 and Mg +2 . A new set of column experiments investigates the effect of wetting and drying cycles on strontium- 90 sorption and migration by considering episodic flow in Hanford sediments. In addition, the effect of fluctuating aquifer chemistry as a result of changes in the Columbia River stage on Sr +2 sorption is addressed. Modeling of multicomponent reactive transport under variably saturated conditions is used to interpret the results of the episodic flow/chemistry experiments. [1] Experimental and modeling studies of the migration behavior of strontium in Hanford sediments, USA. C

  12. A geostatical model for USA uranium deposits

    International Nuclear Information System (INIS)

    Drew, M.W.

    1979-01-01

    Evidence exists which suggests that the frequency distributions of both grade and size of metal deposits may be well approximated by lognormal distribution functions. Using data on presently viable deposits and a simplified function which links production cost to deposit grade and size, a bivariate lognormal deposit grade/size distribution may be calibrated for a given geological environment. Exploration is introduced by assuming that the proportion discovered of the potential uranium reserve available at or below a given production can be represented by a fraction of the average deposit size and the limit exploration expenditure. As output, the model derives estimates of total reserves linked to maximum production costs and to exploration expenditure where the latter may be expressed either as expenditure per lb of mineral discovered or as a given percentage of operating profit. Reserve/price functions have been derived for the USA based on USAEC data. Tentative conclusions which may be drawn from the results are: (1) Assuming that a similar proportion of profits continues to be allocated to exploration in the future, then the USA should be able to meet its own national demand for uranium up to the end of the century (say 2 M tons U) at prices up to US$35/lb U 3 O 8 (1.1.75$ values). (2) If instead of all exploration being funded from a fixed maximum proportion of mining company profits, consumers were to fund additional exploration separately, then it is possible that the total unit cost of uranium to the consumers would thereby be reduced. It should be stressed that these conclusions are tentative and are only as reliable as the input data and assumptions of the model. In particular no account is taken of commercial or political forces which could artificially restrict supplies or raise prices. The model should be regarded as a first attempt and is offered as a basis for discussion leading to further development. (author)

  13. Integrating seismic-reflection and sequence-stratigraphic methods to characterize the hydrogeology of the Floridan aquifer system in southeast Florida

    Science.gov (United States)

    Cunningham, Kevin J.

    2013-01-01

    The Floridan aquifer system (FAS) is receiving increased attention as a result of regulatory restrictions on water-supply withdrawals and treated wastewater management practices. The South Florida Water Management District’s Regional Water Availability Rule, adopted in 2007, restricts urban withdrawals from the shallower Biscayne aquifer to pre-April 2006 levels throughout southeast Florida. Legislation adopted by the State of Florida requires elimination of ocean outfalls of treated wastewater by 2025. These restrictions have necessitated the use of the more deeply buried FAS as an alternate water resource to meet projected water-supply shortfalls, and as a repository for the disposal of wastewater via Class I deep injection wells and injection of reclaimed water. Some resource managers in Broward County have expressed concern regarding the viability of the FAS as an alternative water supply due to a lack of technical data and information regarding its long-term sustainability. Sustainable development and management of the FAS for water supply is uncertain because of the potential risk posed by structural geologic anomalies (faults, fractures, and karst collapse structures) and knowledge gaps in the stratigraphy of the system. The integration of seismic-reflection and borehole data into an improved geologic and hydrogeologic framework will provide a better understanding of the structural and stratigraphic features that influence groundwater flow and contaminant transport.

  14. Multi-scale constraints of sediment source to sink systems in frontier basins: a forward stratigraphic modeling case study of the Levant region

    Science.gov (United States)

    Hawie, Nicolas; Deschamps, Remy; Granjeon, Didier; Nader, Fadi-Henri; Gorini, Christian; Müller, Carla; Montadert, Lucien; Baudin, François

    2015-04-01

    Recent scientific work underlined the presence of a thick Cenozoic infill in the Levant Basin reaching up to 12 km. Interestingly; restricted sedimentation was observed along the Levant margin in the Cenozoic. Since the Late Eocene successive regional geodynamic events affecting Afro-Arabia and Eurasia (collision and strike slip deformation)induced fast marginal uplifts. The initiation of local and long-lived regional drainage systems in the Oligo-Miocene period (e.g. Lebanon versus Nile) provoked a change in the depositional pattern along the Levant margin and basin. A shift from carbonate dominated environments into clastic rich systems has been observed. Through this communication we explore the importance of multi-scale constraints (i.e.,seismic, well and field data) in the quantification of the subsidence history, sediment transport and deposition of a Middle-Upper Miocene "multi-source" to sink system along the northernLevant frontier region. We prove through a comprehensive forward stratigraphic modeling workflow that the contribution to the infill of the northern Levant Basin (offshore Lebanon) is split in between proximal and more distal clastic sources as well as in situ carbonate/hemipelagic deposition. In a wider perspective this work falls under the umbrella of multi-disciplinary source to sink studies that investigate the impact of geodynamic events on basin/margin architectural evolutions, consequent sedimentary infill and thus on petroleum systems assessment.

  15. Late-Holocene vegetation dynamics in response to a changing climate and anthropogenic influences - Insights from stratigraphic records and subfossil trees from southeast Lithuania

    Science.gov (United States)

    Edvardsson, Johannes; Stančikaitė, Miglė; Miras, Yannick; Corona, Christophe; Gryguc, Gražyna; Gedminienė, Laura; Mažeika, Jonas; Stoffel, Markus

    2018-04-01

    To increase our understanding of long-term climate dynamics and its effects on different ecosystems, palaeoclimatic and long-term botanical reconstructions need to be improved, in particular in underutilized geographical regions. In this study, vegetation, (hydro)climate, and land-use changes were documented at two southeast Lithuanian peatland complexes - Čepkeliai and Rieznyčia - for the Late-Holocene period. The documentation was based on a combination of pollen, plant macrofossils, peat stratigraphic records, and subfossil trees. Our results cover the last two millennia and reveal the existence of moist conditions in Southern Lithuania between 300 and 500 CE and from 950 to 1850 CE. Conversely, changes towards warmer and/or dryer conditions have been recorded in 100, 600, and 750 CE, and since the 1850s. Significant differences with other Baltic proxies prevent deriving a complete and precise long-term reconstruction of past hydroclimatic variability at the regional scale. Yet, our results provide an important cornerstone for an improved understanding of regional climate change, i.e. in a region for which only (i) few detailed palaeobotanical studies exist and which has, in addition, been considered as (ii) an ecologically sensitive region at the interface between the temperate and boreal bioclimatic zones.

  16. Representation of the thickness distribution of channels and stratigraphic events at one of the Iranian fields in the Hormuz Strait using a composite plot and RGB display technique

    International Nuclear Information System (INIS)

    Saadatinejad, M R; Javaherian, A; Hassani, H

    2011-01-01

    The Hormuz Strait is an important area which is located between the Persian Gulf, with half the oil reserves of the world, and the Oman Sea south of Iran. Many geophysical studies have been done to analyse the structure of subsurface layers in this strait and explore many new gas reservoirs as these findings help to simulate images from reservoir stratigraphy and understand the paleo-depositional environments. Spectral decomposition, which is a quick and important method in seismic interpretation, provides a strong tool to study these types of subsurface layers. In this paper, a red–green–blue (RGB) multi-colour display technique has been performed as an effective interpretation tool. This technique stacks three different frequencies with three different colours for composite display. So, these frequency components show the distribution of channel thickness as we map the variation of thickness with a colour scale that is equal to the quantitative thickness according to its relationship with frequency. In addition, seismic attributes such as coherency, peak and instantaneous frequency, which are sensitive to the edges of stratigraphic events (such as channels), are shown with a composite plot too; although the RGB technique is better than other techniques, for thickness variation a combined application is the best method of study

  17. The use of Rb-Sr and K-Ar dating methods as a stratigraphic tool applied to sedimentary rocks and minerals

    International Nuclear Information System (INIS)

    Bonhomme, M.G.

    1982-01-01

    Rb-Sr and K-Ar methods can be used for direct numerical chronostratigraphy of sediments using the clay silicates they contain. The interpretation of the ages calculated depends on the satisfaction of the following requirements: (1) The series studied must include diagenetic clay sediments. Coarsely-detrital or slightly-metamorphic formations must be excluded. Studies in progress concerning decarbonatation may lead to the application of direct dating of sediments being extended to carbonate sediments. (2) Careful mineralogical study of the clay minerals must prove early diagenetic recrystallization or new formation. This part of the study must precede any isotopic work. (3) The isotopic study must involve the use of both Rb-Sr and K-Ar methods. The extreme sensibility of the K-Ar isotopic system to late diagenesis helps to choose between early or late diagenesis: a younger K-Ar age may generally be regarded as that of the late diagenesis, whereas the Rb-Sr age may be that of the early diagenesis. (4) The initial 87 Sr/ 86 Sr isotopic ratio is not always a reliable criterion, owing to the effects of the dilution of the radiogenic 87 Sr by the great amounts of primary Sr contained in carbonates. (5) The regularly-decreasing succession of isotopic ages must follow the stratigraphic succession. When this condition is satisfied, there is a high probability that the calculated ages are indeed those of the deposition dates. (Auth.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Bassant, Ph

    1999-06-01

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

  19. President Meri näitas USA-le vabaduse ilu / Daniel Fried ; interv. Kaarel Kaas

    Index Scriptorium Estoniae

    Fried, Daniel, 1952-

    2006-01-01

    USA abivälisminister Daniel Fried USA välispoliitika ühest eesmärgist - demokraatia levitamisest maailmas, demokraatia olukorrast Venemaal ning USA ja Venemaa vahelistest suhetest. Lisa: Daniel Fried

  20. Riskiäri USA kõrbes / Tarmo Vahter, Sulev Vedler

    Index Scriptorium Estoniae

    Vahter, Tarmo, 1970-

    2011-01-01

    Eesti Energia ostis USA kõrbes mahajäetud kaevanduse koos põlevkivivaruga, millest Brasiilia naftagigant Petrobras ja Jaapani suurfirma Mitsui ja Co loobusid. Eesti Energia põlevkiviprojektist USA-s

  1. Vaiksed professionaalid USA erivägedes on tulevased liidrid / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2006-01-01

    USA eriüksuste juhid kinnitavad esiterrorist Osama bin Ladeni peatset tabamist. Floridas Tampas asuvast USA Lähis-Ida operatsioonide peastaabist. Lisa: USA erioperatsioonide keskused. Vt. samas: Ameerika pikk ja väsitav sõda

  2. Ameerikat sõtta õhutanud Iraagi prominent kaotas USA soosingu / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2004-01-01

    Iraaklase Ahmed Chalabi tegevusest ja lubadustest USA Iraagi-vastase sõja alustamiseks. USA toetuse kahanemisest Chalabile ja süüdistustest, et ta andis salajast infot Iraanile USA vägede tegevuse kohta Iraagis

  3. USA ja EL vähendavad kaubandustõkkeid / Kertu Ruus

    Index Scriptorium Estoniae

    Ruus, Kertu, 1977-

    2005-01-01

    Tippkohtumisel Washingtonis arutasid Euroopa Komisjoni president Jose Manuel Barroso ja USA president George W. Bush, kuidas EL-i ja USA majandussuhteid vabamaks muuta. Diagramm: EL-i kaubavahetus USA-ga

  4. USA politoloogid : Obama võit oleks ka Eesti oma / Laura Vetik

    Index Scriptorium Estoniae

    Vetik, Laura

    2008-01-01

    USA politoloogide sõnul oleks pingestunud Venemaa ja USA suhete taustal Eestile kasulikum, kui 56. USA presidendivalimised võidaks demokraat Barack Obama. Erinevate politoloogide hinnanguid. Vt. samas: Obama ja McCain loovad kabinette

  5. Lithofacies and sequence stratigraphic description of the upper part of the Avon Park Formation and the Arcadia Formation in U.S. Geological Survey G–2984 test corehole, Broward County, Florida

    Science.gov (United States)

    Cunningham, Kevin J.; Robinson, Edward

    2017-07-18

    Rock core and sediment from U.S. Geological Survey test corehole G–2984 completed in 2011 in Broward County, Florida, provide an opportunity to improve the understanding of the lithostratigraphic, sequence stratigraphic, and hydrogeologic framework of the intermediate confining unit and Floridan aquifer system in southeastern Florida. A multidisciplinary approach including characterization of sequence stratigraphy, lithofacies, ichnology, foraminiferal paleontology, depositional environments, porosity, and permeability was used to describe the geologic samples from this test corehole. This information has produced a detailed characterization of the lithofacies and sequence stratigraphy of the upper part of the middle Eocene Avon Park Formation and Oligocene to middle Miocene Arcadia Formation. This enhancement of the knowledge of the sequence stratigraphic framework is especially important, because subaerial karst unconformities at the upper boundary of depositional cycles at various hierarchical scales are commonly associated with secondary porosity and enhanced permeability in the Floridan aquifer system.

  6. Pricing behavior of USA exporter in wheat international market

    Science.gov (United States)

    Wibowo, R. P.; Sumono; Iddrisu, Y.; Darus, M.; Sihombing, L. P.; Jufri

    2018-02-01

    The number of wheat producing countries is changing over time. It is expected the change in wheat supply will lead world wheat market become more competitive and reduce market power of major exporter country. This paper tries to identify and examined the degree of market power on wheat international market for USA by using the Pricing to Market (PTM) method. USA is the biggest producer and exporter in wheat market. The PTM method found that USA impose noncompetitive strategy by applying price discrimination and apply market power to their importer country.

  7. Reevaluation of the Piermont-Frontenac allochthon in the Upper Connecticut Valley: Restoration of a coherent Boundary Mountains–Bronson Hill stratigraphic sequence

    Science.gov (United States)

    Rankin, Douglas W.; Tucker, Robert D.; Amelin, Yuri

    2013-01-01

    The regional extent and mode and time of emplacement of the Piermont-Frontenac allochthon in the Boundary Mountains–Bronson Hill anticlinorium of the Upper Connecticut Valley, New Hampshire–Vermont, are controversial. Moench and coworkers beginning in the 1980s proposed that much of the autochthonous pre–Middle Ordovician section of the anticlinorium was a large allochthon of Silurian to Early Devonian rocks correlated to those near Rangeley, Maine. This ∼200-km-long allochthon was postulated to have been transported westward in the latest Silurian to Early Devonian as a soft-sediment gravity slide on a hypothesized Foster Hill fault. New mapping and U-Pb geochronology do not support this interpretation. The undisputed Rangeley sequence in the Bean Brook slice is different from the disputed sequence in the proposed larger Piermont-Frontenac allochthon, and field evidence for the Foster Hill fault is lacking. At the type locality on Foster Hill, the postulated “fault” is a stratigraphic contact within the Ordovician Ammonoosuc Volcanics. The proposed Foster Hill fault would place the Piermont-Frontenac allochthon over the inverted limb of the Cornish(?) nappe, which includes the Emsian Littleton Formation, thus limiting the alleged submarine slide to post-Emsian time. Mafic dikes of the 419 Ma Comerford Intrusive Complex intrude previously folded strata attributed to the larger Piermont-Frontenac allochthon as well as the autochthonous Albee Formation and Ammonoosuc Volcanics. The Lost Nation pluton intruded and produced hornfels in previously deformed Albee strata. Zircons from an apophysis of the pluton in the hornfels have a thermal ionization mass spectrometry 207Pb/206Pb age of 444.1 ± 2.1 Ma. Tonalite near Bath, New Hampshire, has a zircon sensitive high-resolution ion microprobe 206Pb/238U age of 492.5 ± 7.8 Ma. The tonalite intrudes the Albee Formation, formerly interpreted as the Silurian Perry Mountain Formation of the proposed allochthon

  8. Ordovician and Silurian Phi Kappa and Trail Creek formations, Pioneer Mountains, central Idaho; stratigraphic and structural revisions, and new data on graptolite faunas

    Science.gov (United States)

    Dover, James H.; Berry, William B.N.; Ross, Reuben James

    1980-01-01

    Recent geologic mapping in the northern Pioneer Mountains combined with the identification of graptolites from 116 new collections indicate that the Ordovician and Silurian Phi Kappa and Trail Creek Formations occur in a series of thrust-bounded slices within a broad zone of imbricate thrust faulting. Though confirming a deformational style first reported in a 1963 study by Michael Churkin, our data suggest that the complexity and regional extent of the thrust zone were not previously recognized. Most previously published sections of the Phi Kappa and Trail Creek Formations were measured across unrecognized thrust faults and therefore include not only structural repetitions of graptolitic Ordovician and Silurian rocks but also other tectonically juxtaposed lithostratigraphic units of diverse ages as well. Because of this discovery, the need to reconsider the stratigraphic validity of these formations and their lithology, nomenclature, structural distribution, facies relations, and graptolite faunas has arisen. The Phi Kappa Formation in most thrust slices has internal stratigraphic continuity despite the intensity of deformation to which it was subjected. As revised herein, the Phi Kappa Formation is restricted to a structurally repeated succession of predominantly black, carbonaceous, graptolitic argillite and shale. Some limy, light-gray-weathering shale occurs in the middle part of the section, and fine-grained locally pebbly quartzite is present at the base. The basal quartzite is here named the Basin Gulch Quartzite Member of the Phi Kappa. The Phi Kappa redefined on a lithologic basis represents the span of Ordovician time from W. B. N. Berry's graptolite zones 2-4 through 15 and also includes approximately 17 m of lithologically identical shale of Early and Middle Silurian age at the top. The lower contact of the formation as revised is tectonic. The Phi Kappa is gradationally overlain by the Trail Creek Formation as restricted herein. Most of the coarser

  9. Defeating diplostomoid dangers in USA catfish aquaculture.

    Science.gov (United States)

    Overstreet, Robin M; Curran, Stephen S

    2004-06-01

    Diplostomoid digenean metacercariae have caused widescale mortalities of channel catfish, Ictalurus punctatus (Rafinesque), at aquaculture farms in Louisiana, Mississippi and Arkansas, USA. Originally, based on a tentative diagnosis, the industry considered the primary harmful agent to be an introduced species from Europe, Bolbophorus confusus (Krause, 1914), frequently reported from the American white pelican, Pelecanus erythrorhynchos Gmelin. Our group has now shown, using ITS 1-2 plus three more-conservative gene fragments, that two sympatric species of Bolbophorus exist in the American white pelican. One, B. damnificus Overstreet et Curran, 2002, infects the musculature of catfish, and the other, probably not B. confusus, does not infect catfish. However, at least four other pathogenic diplostomoids and a clinostomoid infect the catfish, and they use at least four different snail hosts, including the planorbids Planorbella trivolvis (Say) and Gyraulus parvus (Say), the physid Physella gyrina (Say) and a lymnaeid. Two metacercariae, B. damnificus and Bursacetabulus pelecanus Dronen, Tehrany et Wardle, 1999, infect the catfish and mature in the pelican; two others, Austrodiplostomum compactum (Lutz, 1928) and Hysteromorpha cf. triloba (Rudolphi, 1819), mature in cormorants; one, Diplostomum sp., matures in seagulls and at least one, Clinostomum marginatum (Rudolphi, 1819), matures in herons, egrets and other wading birds. Consequently, management of catfish ponds relative to digenean infections requires considerable biological information on the fish, bird, and snail hosts as well as the parasites.

  10. A BWR licensing experience in the USA

    International Nuclear Information System (INIS)

    Powers, J.; Ogura, C.; Arai, K.; Thomas, S.; Mookhoek, B.

    2015-09-01

    The US-Advanced Boiling Water Reactor (A BWR), certified by the United States Nuclear Regulatory Commission (US NRC), is a third generation, evolutionary boiling water reactor design which is the reference for the South Texas Project Units 3 and 4 (STP3-4) Combined License Application (Cola). Nuclear Innovation North America (Nina) is the License Applicant for this new build project, and Toshiba is the selected primary technology contractor. The STP3-4 project has finished the US NRC technical review of the Cola through the final meeting of the Advisory Committee on Reactor Safeguards (ACRS), and the Final Safety Evaluation Report (FSER) is scheduled to be issued by the US NRC in the middle of 2015. The next steps are to support the Mandatory Hearing process, and voting by the NRC commissioners on the motion to grant the Combined License, which is scheduled beginning of 2016 according to US NRC schedule as of March 30, 2015. This paper summarizes the history and progress of the US-A BWR licensing, including the experiences of the Licensee, Nina, and Toshiba as the Epc team worked through the Code of Federal Regulations Title 10 (10-Cfr) Part 52 process, and provides some perspectives on how the related licensing material would also be of value within a 10-Cfr Part 50, two-step process to minimize schedule and financial risks which could arise from ongoing technical developments and regulatory reviews. (Author)

  11. Causes of sinks near Tucson, Arizona, USA

    Science.gov (United States)

    Hoffmann, J.P.; Pool, D.R.; Konieczki, A.D.; Carpenter, M.C.

    1998-01-01

    Land subsidence in the form of sinks has occurred on and near farmlands near Tucson, Pima County, Arizona, USA. The sinks occur in alluvial deposits along the flood plain of the Santa Cruz River, and have made farmlands dangerous and unsuitable for farming. More than 1700 sinks are confined to the flood plain of the Santa Cruz River and are grouped along two north-northwestward-trending bands that are approximately parallel to the river and other flood-plain drainages. An estimated 17,000 m3 of sediment have been removed in the formation of the sinks. Thirteen trenches were dug to depths of 4-6 m to characterize near-surface sediments in sink and nonsink areas. Sediments below about 2 m included a large percentage of dispersive clays in sink areas. Sediments in nonsink areas contain a large component of medium- to coarse-grained, moderately to well sorted sand that probably fills a paleochannel. Electromagnetic surveys support the association of silts and clays in sink areas that are highly electrically conductive relative to sand in nonsink areas. Sinks probably are caused by the near-surface process of subsurface erosion of dispersive sediments along pre-existing cracks in predominantly silt and clay sediments. The pre-existing cracks probably result from desiccation or tension that developed during periods of water-table decline and channel incision during the past 100 years or in earlier periods.

  12. A BWR licensing experience in the USA

    Energy Technology Data Exchange (ETDEWEB)

    Powers, J.; Ogura, C. [Toshiba America Nuclear Energy, Charlotte, North Carolina (United States); Arai, K. [Toshiba Corporation, Yokohama, Kanagawa (Japan); Thomas, S.; Mookhoek, B., E-mail: jim.powers@toshiba.com [Nuclear Innovation North America, Lake Jackson, Texas (United States)

    2015-09-15

    The US-Advanced Boiling Water Reactor (A BWR), certified by the United States Nuclear Regulatory Commission (US NRC), is a third generation, evolutionary boiling water reactor design which is the reference for the South Texas Project Units 3 and 4 (STP3-4) Combined License Application (Cola). Nuclear Innovation North America (Nina) is the License Applicant for this new build project, and Toshiba is the selected primary technology contractor. The STP3-4 project has finished the US NRC technical review of the Cola through the final meeting of the Advisory Committee on Reactor Safeguards (ACRS), and the Final Safety Evaluation Report (FSER) is scheduled to be issued by the US NRC in the middle of 2015. The next steps are to support the Mandatory Hearing process, and voting by the NRC commissioners on the motion to grant the Combined License, which is scheduled beginning of 2016 according to US NRC schedule as of March 30, 2015. This paper summarizes the history and progress of the US-A BWR licensing, including the experiences of the Licensee, Nina, and Toshiba as the Epc team worked through the Code of Federal Regulations Title 10 (10-Cfr) Part 52 process, and provides some perspectives on how the related licensing material would also be of value within a 10-Cfr Part 50, two-step process to minimize schedule and financial risks which could arise from ongoing technical developments and regulatory reviews. (Author)

  13. Recurrent Kawasaki disease: USA and Japan.

    Science.gov (United States)

    Maddox, Ryan A; Holman, Robert C; Uehara, Ritei; Callinan, Laura S; Guest, Jodie L; Schonberger, Lawrence B; Nakamura, Yosikazu; Yashiro, Mayumi; Belay, Ermias D

    2015-12-01

    Descriptive epidemiologic studies of recurrent and non-recurrent Kawasaki disease (KD) may identify other potentially important differences between these illnesses. Data from the USA and Japan, the Centers for Disease Control and Prevention (CDC) national KD surveillance(1984-2008) and the 17th Japanese nationwide survey (2001-2002), respectively, were analyzed to examine recurrent KD patients <18 years of age meeting the CDC KD case or atypical KD case definition. These patients were compared with non-recurrent KD patients. Of the 5557 US KD patients <18 years of age during 1984-2008, 97 (1.7%) were identified as having had recurrent KD. Among the US Asian/Pacific Islander KD patients, 3.5% had recurrent KD, which was similar to the percentage identified among KD patients (3.5%) in the Japanese survey. Compared with non-recurrent KD patients, KD patients [with recurrent KD] were more likely to be older, fulfill the atypical KD case definition, and have coronary artery abnormalities (CAA) despite i.v. immunoglobulin (IVIG) treatment. Differences in the age, race, and frequency of CAA exist between recurrent and non-recurrent KD patients. The increased association of CAA with recurrent KD suggests that more aggressive treatment strategies in conjunction with IVIG may be indicated for the second episode of KD. © 2015 Japan Pediatric Society.

  14. Stratigraphic and structural controls on groundwater flow in an outcropping fossil fan delta: the case of Sant Llorenç del Munt range (NE Spain)

    Science.gov (United States)

    Anglés, Marc; Folch, Albert; Oms, Oriol; Maestro, Eudald; Mas-Pla, Josep

    2017-12-01

    Hydrogeological models of mountain regions present the opportunity to understand the role of geological factors on groundwater resources. The effects of sedimentary facies and fracture distribution on groundwater flow and resource exploitation are studied in the ancient fan delta of Sant Llorenç de Munt (central Catalonia, Spain) by integrating geological field observations (using sequence stratigraphy methods) and hydrogeological data (pumping tests, hydrochemistry and environmental isotopes). A comprehensive analysis of data portrays the massif as a single unit, constituted by different compartments determined by specific layers and sets of fractures. Two distinct flow systems—local and regional—are identified based on pumping test analysis as well as hydrochemical and isotopic data. Drawdown curves derived from pumping tests indicate that the behavior of the saturated layers, whose main porosity is given by the fracture network, corresponds to a confined aquifer. Pumping tests also reflect a double porosity within the system and the occurrence of impervious boundaries that support a compartmentalized model for the whole aquifer system. Hydrochemical data and associated spatial evolution show the result of water-rock interaction along the flow lines. Concentration of magnesium, derived from dolomite dissolution, is a tracer of the flow-path along distinct stratigraphic units. Water stable isotopes indicate that evaporation (near a 5% loss) occurs in a thick unsaturated zone within the massif before infiltration reaches the water table. The hydrogeological analysis of this outcropping system provides a methodology for the conceptualization of groundwater flow in similar buried systems where logging and hydrogeological information are scarce.

  15. Uplift history of a transform continental margin revealed by the stratigraphic record: The case of the Agulhas transform margin along the Southern African Plateau

    Science.gov (United States)

    Baby, Guillaume; Guillocheau, François; Boulogne, Carl; Robin, Cécile; Dall'Asta, Massimo

    2018-04-01

    The south and southeast coast of southern Africa (from 28°S to 33°S) forms a high-elevated transform passive margin bounded to the east by the Agulhas-Falkland Fracture Zone (AFFZ). We analysed the stratigraphic record of the Outeniqua and Durban (Thekwini) Basins, located on the African side of the AFFZ, to determine the evolution of these margins from the rifting stage to present-day. The goal was to reconstruct the strike-slip evolution of the Agulhas Margin and the uplift of the inland high-elevation South African Plateau. The Agulhas transform passive margin results from four successive stages: Rifting stage, from Late Triassic to Early Cretaceous ( 200?-134 Ma), punctuated by three successive rifting episodes related to the Gondwana breakup; Wrench stage (134-131 Ma), evidenced by strike- and dip-slip deformations increasing toward the AFFZ; Active transform margin stage (131-92 Ma), during which the Falkland/Malvinas Plateau drifts away along the AFFZ, with an uplift of the northeastern part of the Outeniqua Basin progressively migrating toward the west; Thermal subsidence stage (92-0 Ma), marked by a major change in the configuration of the margin (onset of the shelf-break passive margin morphology). Two main periods of uplift were documented during the thermal subsidence stage of the Agulhas Margin: (1) a 92 Ma short-lived margin-scale uplift, followed by a second one at 76 Ma located along the Outeniqua Basin and; (2) a long-lasting uplift from 40 to 15 Ma limited to the Durban (Thekwini) Basin. This suggests that the South African Plateau is an old Upper Cretaceous relief (90-70 Ma) reactivated during Late Eocene to Early Miocene times (40-15 Ma).

  16. The occurrence, origin and stratigraphic significance of bone-bearing mudstone pellet conglomerates from the Beaufort group in the Jansenville district, Cape Province, South Africa

    International Nuclear Information System (INIS)

    Turner, B.R.

    1981-01-01

    The lack of useful lithostratigraphic markers in the Beaufort Group in the southern Karoo Basin has focused attention on the biostratigraphy of the sediments. As a result a more refined scheme of biostratigraphic classification is now possible which may prove useful in fixing the stratigraphic position of the uranium mineralized horizons. The most important mineralized horizon in the Beaufort West area (contains about 90 per cent of all known uranium occurrences) is associated with the Pristerognathus/Diictodon assemblage zone, but the way in which this relates to the important uranium occurrences farther east, between Graaff-Reinet and Jansenville, is uncertain because of the lack of biostratigraphic control. Vertebrate remains have recently been found in mudstone pellet conglomerates in Beaufort channel sandstones along the Bullrivier in the Jansenville District, in an area that is extensively mineralized. The sandstones were deposited as point bar sands within a meandering river system flowing towards the north-east. The rivers drained a dry, arid to semi-arid alluvial plain and were characterized by fluctuating discharge and periods of low or negligible flow. These conditions promoted flood scour and fill activity and the deposition of internal mudstone pellet conglomerates. Hydrodynamic considerations suggest that estimates of bone transport velocity from their hydrodynamically equivalent quartz sphere is of limited value and can seldom, if ever, be applied to fossil bone accumulations. Identification of the bones from the conglomerates indicates that they belong to the Dino-cephalia biozone and not the overlying Pristerognathus/Diictodon zone. This suggests that the lower part of the Beaufort succession (formerly the Tapinocephalus zone) extends farther east than previously thought, and that the main mineralized horizon in this area occurs lower down in the succession than that around Beaufort West

  17. Facies architecture and stratigraphic evolution of aeolian dune and interdune deposits, Permian Caldeirão Member (Santa Brígida Formation), Brazil

    Science.gov (United States)

    Jones, Fábio Herbert; Scherer, Claiton Marlon dos Santos; Kuchle, Juliano

    2016-05-01

    The Permian Caldeirão Member (Santa Brígida Formation), located in the Tucano Central Basin, northeast region of Brazil, is characterized by a sandstone succession of aeolian origin that comprises the preserved deposits of dunes and interdunes. Grainflow and translatent wind-ripple strata, and frequent presence of reactivation surface, compose the cross-bedding of crescent aeolian dune deposits. The aeolian cross-strata show a mean dip toward the ENE. In places, interlayered with dune cross-beds, occur interdune units composed of facies indicative of dry, damp and wet condition of the substrate, suggesting spatial and/or temporal variations in the moisture content of the interdune accumulation surface. The presence of NNW current ripple cross-lamination in wet interdune areas indicates streamflows confined to interdune corridors and oriented perpendicular to aeolian transport direction. Lenses of damp and wet interdune strata exhibit mainly interdigitated and transitional relationships with the toe-sets of overlying aeolian dune units in sections parallel to aeolian transport, indicating that dune migration was contemporaneous with accumulation in adjacent interdunes. Lateral variations in the preserved thickness of the interdune units and the associated rare occurrence of abrupt and erosive contacts between interdune and overlying dune sets, suggest temporal variations in the angle of dune and interdune climb that may be related to high-frequency changes in water table position. Four stratigraphic intervals in the Caldeirão Member can be identified, two intervals showing cross-bedding of aeolian dunes without wet interdune areas and two intervals exhibiting aeolian dunes separated by wet interdune areas, marking the transition between dry aeolian systems (Intervals I and III) and wet aeolian systems (Intervals II and IV). The temporal alternations between dry and wet aeolian systems reflect changes in the availability of dry sand and/or the rate in the water

  18. The Cretaceous-Paleogene transition and Chicxulub impact ejecta in the northwestern Gulf of Mexico: Paleoenvironments, sequence stratigraphic setting and target lithologies

    Science.gov (United States)

    Schulte, Peter

    2003-07-01

    The Cretaceous-Paleogene (K-P) transition is characterized by a period of mass extinctions, the Chicxulub impact event, sea-level changes, and considerable climate changes (e.g., cooling). The Gulf of Mexico region is a key area for addressing these issues, specifically because of the proximity to the large Chicxulub impact structure in southern Mexico, and because of its shallow shelf areas throughout the Maastrichtian to Danian period. This study presents the results of a multidisciplinary investigation of Chicxulub impact ejecta and marine sediments from the K-P transition in the western Gulf of Mexico. Sedimentological, mineralogical, and geochemical aspects of K-P sections and cores from northeastern Mexico, Texas, and Alabama have been by studied with focus on Chicxulub ejecta, long- or short-term facies change, and sequence stratigraphic setting. CHICXULUB EJECTA: The Chicxulub ejecta (or impact spherule) deposits from northeastern Mexico and Texas revealed an unexpected complex and localized ejecta composition. Fe-Mg-rich chlorite- as well as Si-Al-K-rich glass-spherules are the predominant silicic ejecta components in northeastern Mexico, whereas in Texas, spherules of Mg-rich smectite compositions were encountered. Spherules contain Fe-Ti-K-rich schlieren, Fe-Mg-rich globules, and rare µm-sized metallic and sulfidic Ni-Co-(Ir-?) rich inclusions. This composition provides evidence for a distinct range of target rocks of mafic to intermediate composition, presumably situated in the northwestern sector of the Chicxulub impact structure, in addition to the possibility of contamination by meteoritic material. The absence of spinels and the ubiquitous presence of hematite and goethite points to high oxygen fugacity during the impact process. Besides these silicic phases, the most prominent ejecta component is carbonate.! Carbonate is found in ejecta deposits as unshocked clasts, accretionary lapilli-like grains, melt globules (often with quenching textures

  19. Unearthing The Eruptive Personality Of El Salvador's Santa Ana (Ilamatepec) Volcano Though In-depth Stratigraphic Analysis Of Pre-1904 Deposits

    Science.gov (United States)

    Gallant, E.; Martinez-Hackert, B.

    2011-12-01

    The Santa Ana (Ilamatepec) volcano (2384 m) in densely populated El Salvador Central America presents serious volcanic hazard potential. The volcano is a prevalent part of every day life in El Salvador; the sugarcane and coffee belt of the country are to its Southern and Western flanks, recreational areas lies to its East, and second and third largest cities of El Salvador exist within its 25 km radius. Understanding the eruptive characteristics and history is imperative due to the volcano's relative size (the highest in the country) and it's explosive, composite nature. Historical records indicate at least 9 potential VEI 3 eruptions since 1521 AD. The volcano's relative inaccessibility and potential hazards do not promote a vast reservoir of research activity, as can be seen in the scarcity of published papers on topics prior to the 1904 eruption. This research represents the first steps towards creating a comprehensive stratigraphic record of the crater and characterizing its eruptive history, with an eventual goal of recreating the volcanic structure prior to its collapse. Samples of pre-1904 eruptive material were taken from the southern wall of an E-W oriented fluvial gully located within the SSW of the tertiary crater. These were analyzed using thin sections and optical microscopy, grain size distribution techniques, and scanning electron microscopy. The 15-layer sequence indicates an explosive history characterized by intense phreatomagmatic phases, plinian, sub-plinian and basaltic/andesitic composition strombolian activity. Another poster within the session will discuss an older sequence within the walls of the secondary crater. Further detailed studies will be required to gain a better understanding of the characteristics of Santa Ana Volcano.

  20. Coupling Geophysical, Geotechnical and Stratigraphic Data to Interpret the Genesis of Mega-Scale-Glacial-Lineations on the Yermak Plateau, Arctic Ocean

    Science.gov (United States)

    O'Regan, M. A.; Jakobsson, M.; Kirchner, N.; Dowdeswell, J. A.; Hogan, K.

    2010-12-01

    The recent collection and analysis of multi-beam bathymetry data has revealed Mega-Scale Glacial Lineations (MSGL) in up to 600 m present water depth on the Yermak Plateau (Dowdeswell et al., 2010; Jakobsson et al., 2010). This evidence for large-scale ice grounding in the region supports previous interpretations from side-scan sonar, high-resolution subbottom and multi-channel seismic data. Detailed integration with regional subbottom data illustrates that the formation of the MSGL occurred in the late Quaternary, around MIS6. This event is distinct from a middle Quaternary ice grounding in the same region, that was first recognized by the transition into heavily overconsolidated sediments at ~20 mbsf at Ocean Drilling Program Site 910. While the middle Quaternary ice grounding left an easily recognizable imprint on the geotechnical properties of the sediments, the imprint from the late Quaternary event is far subtler, and not formerly recognized by analysis of sediments from Site 910. Furthermore, stratigraphic information indicates that neither event was associated with significant erosion, implying that the observed stress state of the sediments arose from ice-loading. Coupled with the orientation of the late Quaternary MSGL, the available evidence argues against an active ice-stream being responsible for their formation, and that they were more likely formed by a very large tabular iceberg traversing the ridge. This lends considerable support to the argument that MSGL-like features are not exclusively associated with fast flowing ice-streams. References Jakobsson, M., et al., An Arctic Ocean iceshelf during MIS 6 constrained by new geophysical and geological data. Quaternary Science Reviews (2010), doi:10.1016/j.quascirev.2010.03.015. Dowdeswell, J. A., et al., High-resolution geophysical observations of the Yermak Plateau and northern Svalbard margin: implications for ice-sheet grounding and deep-keeled icebergs. Quaternary Science Reviews (2010), doi:10

  1. Correlation and stratigraphic eruption age of the pyroclastic flow deposits and wide spread volcanic ashes intercalated in the Pliocene-Pleistocene strata, central Japan

    International Nuclear Information System (INIS)

    Nagahashi, Yoshitaka; Satoguchi, Yasufumi; Yoshikawa, Shusaku

    2000-01-01

    Three pyroclastic flow deposits in the Takayama and Omine area, central Honshu, are correlated to the distal widespread volcanic ashes intercalated in the Plio-Pleistocene boundary strata in central Japan. The correlation is based on these stratigraphic relationships, facies, magnetostratigraphy, petrographic properties such as mineral assemblage, refractive index and chemical composition of the volcanic glasses and orthopyroxene. As the result of these correlation, the eruption age of the proximal pyroclastic flow deposits have become clear. And precise correlation between proximal eruption units and distal depositional units is now possible. Ho-Kd 39 Tephra erupted at about 1.76 Ma, forming a co-ignimbrite ash, which deposited in the Kanto sedimentary basin. Eb-Fukuda Tephra erupted at about 1.75 Ma, and distal volcaniclastic deposit sedimented in the Kinki, Niigata and Kanto sedimentary basins. The eruptional and depositional phase are divided into the stage 1, stage 2 (early), stage 2 (late) and stage 3. Stage 1 is phreato-plinian type eruption phase, forming distal ash fall deposit. Stage 2 (early) is plinian pumice fall, intra-plinian pyroclastic flow and plinian pumice fall eruption phase, forming distal ash fall. Stage 2 (late) is final eruptional phase of the biggest pyroclastic flow of the Eb-Fukuda Tephra, forming a co-ignimbrite ash fall. Stage 3 is resedimented stage after the end of the explosive eruption. It is notable that resedimented volcaniclastic deposit reached Osaka sedimentary basin 300 km away from the eruption center. Om-SK110 Tephra erupted at about 1.65 Ma, divided into the stage 1, stage 2 and stage 3. Stage 1 is eruption phase of the plinian pumice fall and first pyroclastic flow. Stage 2 is pauses in eruption activity. Stage 3 is second pyroclastic flow phase, it is inferred that the pyroclastic flow of the stage 3 directly entered the Niigata sedimentary basin and simultaneously formed a co-ignimbrite ash. (author)

  2. Use of radiometric (Cs-137, Pb-210), geomorphic, and stratigraphic techniques to date recent oxbow sediments in the Rio Puerco drainage Grants uranium region, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Popp, C.J.; Dehn, M. (New Mexico Inst. of Mining and Tech., Socorro (United States)); Hawley, J.W.; Love, D.W. (New Mexico Bureau of Mines and Mineral Resources, Socorro (United States))

    1988-06-01

    In the absence of historic geochemical baseline data for the Grants uranium region, environmental changes resulting from uranium mine-mill activities can be determined only by indirect methods. A methodology for determining the age of recent sediments in streams draining the region has been established based on combined geomorphic, stratigraphic, and radiometric dating techniques. Because clay-rich sediments retain possible radionuclides and heavy metals derived from mineralization and mined sources, sample sites which contain fine-grained deposits that both predate and postdate mine-mill activity were located in abandoned-channel segments (oxbows) of major streams draining the eastern Grants uranium region. Aerial photographs (and derivative maps) taken between 1935 and 1971 provided the historical and geomorphic documentation of approximate dates of oxbow formation and ages of alluvial fills in the abandoned-channel segments. Pits were dug at these oxbow sites to determine stratigraphy and composition of the deposits. Samples collected from pit walls and auger holes below the pits were subjected to radiometric analysis by gamma ray spectrometry for the artificial radionuclide Cs-137 and the natural radionuclide Pb-210 as well as other U-238 and Th-232 daughters. Because of the dynamic nature of the system, absolute dating with Cs-137 was not possible but samples could be dated as either pre- or post-1950. The 1950 date is important because it marked the beginning of the uranium exploitation in the region. The Pb-210 dating was not possible because background Pb-210 was very high relative to fallout Pb-210.

  3. High-resolution well-log derived dielectric properties of gas-hydrate-bearing sediments, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Science.gov (United States)

    Sun, Y.; Goldberg, D.; Collett, T.; Hunter, R.

    2011-01-01

    A dielectric logging tool, electromagnetic propagation tool (EPT), was deployed in 2007 in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert Well), North Slope, Alaska. The measured dielectric properties in the Mount Elbert well, combined with density log measurements, result in a vertical high-resolution (cm-scale) estimate of gas hydrate saturation. Two hydrate-bearing sand reservoirs about 20 m thick were identified using the EPT log and exhibited gas-hydrate saturation estimates ranging from 45% to 85%. In hydrate-bearing zones where variation of hole size and oil-based mud invasion are minimal, EPT-based gas hydrate saturation estimates on average agree well with lower vertical resolution estimates from the nuclear magnetic resonance logs; however, saturation and porosity estimates based on EPT logs are not reliable in intervals with substantial variations in borehole diameter and oil-based invasion.EPT log interpretation reveals many thin-bedded layers at various depths, both above and below the thick continuous hydrate occurrences, which range from 30-cm to about 1-m thick. Such thin layers are not indicated in other well logs, or from the visual observation of core, with the exception of the image log recorded by the oil-base microimager. We also observe that EPT dielectric measurements can be used to accurately detect fine-scale changes in lithology and pore fluid properties of hydrate-bearing sediments where variation of hole size is minimal. EPT measurements may thus provide high-resolution in-situ hydrate saturation estimates for comparison and calibration with laboratory analysis. ?? 2010 Elsevier Ltd.

  4. High resolution seismic stratigraphic analysis. An integrated approach to the subsurface geology of the SE Persian Gulf[Paper 2 is not open for the public

    Energy Technology Data Exchange (ETDEWEB)

    Farzadi, Pourdad

    2006-07-01

    Dariyan. The traditional surface based seismic interpretation only gives insights into variability at the top and base of this formation and not from within it. To enhance internal stratigraphic relations a multivariate seismic analysis, combined with a data reduction algorithm, enabled interpretation in an integrated fashion to construct a sequence stratigraphic framework. Six seismic attribute volumes were used, and Principal Component Analysis (PCA) reduced noise and redundant data. Three eustatically-controlled depositional units are recognized in the Dariyan Formation from well data. By analogy with the Shu'aiba, isolated rudist-dominated build-ups in the middle fining-upward unit probably have the best reservoir potential. The extent of platforms and shelf flooding such as the Mishrif and Dariyan reservoirs discussed in this study is generally greatest during sea-level high stands. The carbonate factory is most robust and carbonate sedimentation is greatest at such times. The studied depositional processes result in a variety of stratal geometries, ranging from parallel platform-interior beds to gently- to steeply-dipping fore slope beds, and complex-massive- to chaotically-bedded platform margin facies. The shingled geometry of the reservoir intervals is expressed as a series of bas inward inclined clinoforms. Turonian subaerial exposure of massive carbonates of the Mishrif Formation led to extensive karst formation. Karstification disrupted the normal bedding patterns at the top of the Mishrif Formation making chaotic stratal patterns, and dissolution expanded and enhanced fractures. This provides opportunity for complex raypaths, dispersion of wavefronts, and multiple diffraction points causing a lowered seismic resolution. Distinctive chaotic seismic facies with circular sinkhole and collapse features, discovered by integrated attribute analysis of the Mishrif Formation, clearly correlate with the production rates of existing wells. Pro grading high stand

  5. Stratigraphic position, origin and characteristics of manganese mineralization horizons in the Late Cretaceous volcano-sedimentary sequence, south-southwest of Sabzevar

    Directory of Open Access Journals (Sweden)

    Sajjad Maghfouri

    2014-10-01

    Full Text Available Introduction The Mn mineralization occurs in the northeastern segment of the Sabzevar zone (SZ, north of the Central Iranian Microcontinent (CIM. This Zone (SZ is located between the CIM fragmentation in the south and the Kopeh dagh sedimentary sequence in the north. The ore deposits of the northeastern segment of the Sabzevar zone can be divided into three groups, each with different metal association and spatial distribution and each related to a major geodynamic event. The first mineralization with associated Ordovician host rock is characterized by Taknar polymetallic (Fe-rich massive sulfide deposit. The Cretaceous mineralization consists of Cr deposits associated with serpentinized peridotites, Cyprus type VMS, Mn deposit in pillow lava, volcano-sedimentary hosted Besshi type VMS and Mn deposit. Paleogene mineralization in eastern segment of the Sabzevar zone began with porphyry deposits, Cu Red Bed mineralization occurs in the Paleogene sandy red marl. Materials and methods A field study and sampling was performed during the autumn of 2012. To assess the geochemical characteristics of 48 systematic samples (least fractured and altered of ore-bearing layers and host rocks were collected from the deposit for polished thin section examination. In order to correctly characterize their chemical compositions, 15 least-altered and fractured samples were chosen for major elements analysis. Results The Late Cretaceous volcano-sedimentary sequence in south-southwest of Sabzevar hosts numerous manganese mineralization. The sequence based on the stratigraphic position, age and composition of the rocks, can be divided into two lower and upper parts. The lower part or K2tv unit mainly formed from marine sediments interbedded with volcanic rocks. The sedimentary rocks of this part include silicified tuff, chert, shale and sandstone, and the volcanic rocks involve pyroclastic rocks of various composition, rhyolite, dacite and andesitic lava. The upper

  6. Curt Teichert - Dokumente zu einer Emigration (Dänemark - Australien - USA)

    Science.gov (United States)

    Seibold, Eugen; Seibold, Ilse

    2008-05-01

    Curt Teichert (Königsberg 1905—Arlington, Virginia 1996) provides in his life story examples of the many hardships and difficulties encountered by emigrants who were fortunate to escape Hitleŕs regime. He was a great paleontologist and stratigrapher whose fieldwork on four continents involved nearly every fossil group; his interests were focussed mainly on the Paleozoic and the Triassic. His results and critical remarks on many general topics filled numerous publications. Remarkably, he accomplished all this under partly very unfavorable working conditions. He donated his scientific correspondence from his times in Germany, Denmark and Australia to the Geological Archive in Freiburg. The following article makes use of these documents. Teichert’s professional career started in Germany in the scientifically exciting nineteen-twenties; he worked at the universities in Königsberg, Munich and Freiburg/Breisgau. In Freiburg, however, he had serious disagreements with the Director of the Geological Institute there—this in spite of his investigations having produced some excellent results. The times around 1930 were a period of a global economic crisis, and, like many others, he could only survive financially by getting fellowships from different institutions and payments for publications. In 1933, his situation in Germany became even more critical: this was because he had married a “Non-Aryan”. However, he was able to work in Copenhagen from the end of 1933; this was largely a result of his having participated in 1931 1932 in an expedition to Greenland led by the Dane Lauge Koch. Unfortunately, he could not get a permanent position in Copenhagen because the relations between him and the influential Koch became very unpleasant. Noting Hitleŕs war preparation, Teichert tried to escape from Europe. He wrote many touching letters to correspondents around the globe, receiving mostly disappointing answers. Finally, in 1937, he succeeded in getting the post of a

  7. Ameerika suursaadik Aldona Sofia Wos : toon kättpidi USA suurfirmad Eestisse / Aldona Zofia Wos ; interv. Airi Ilisson

    Index Scriptorium Estoniae

    Wos, Aldona Zofia

    2005-01-01

    USA suursaadik Eestis vastab küsimustele, mis on seotud Londonis USA riigidepartemangu korraldatud konverentsiga, kus Balti riikide juhid rääkisid USA ettevõtete esindajatele, miks tuleks investeerida Balti riikidesse. USA tehtud investeeringutest Eestisse, Eesti ettevõtjate võimalustest USA-s. Lisa: Tõhus rahapüüdja

  8. The climate protection policy of the USA under president Obama; Die Klimaschutzpolitik der USA unter Praesident Obama

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Wolfgang; Schenk, Olga [Forschungszentrum Juelich (Germany). Inst. fuer Energieforschung - Systemforschung und Technologische Entwicklung; Holtrup-Mostert, Petra [Transatlantic Networks - Foreign Policy Analysis, Koenigswinter (Germany)

    2009-01-15

    Barack Obama's slogan 'Are you ready for a Change?' may become the motto fo the future climate protection policy of the USA. While the USA is slowly beginning to play a more active role in this area, there are many political and institutional obstacles to overcome before the USA can become one of the big global players here. The authors analyse the status quo of the US climate protection policy in an attempt to indicate national and international perspectives of climate protection. (orig.)

  9. 2002 Bird Strike Committee USA/Canada Conference

    National Research Council Canada - National Science Library

    Dolbeer, Richard

    2002-01-01

    Over 380 people from 20 countries and 17 exhibitors attended the 4th annual joint meeting of Bird Strike Committee-USA and Bird Strike Committee Canada in Sacramento, California on October 21-24, 2002...

  10. Emmonsia helica Infection in HIV-Infected Man, California, USA.

    Science.gov (United States)

    Rofael, Martin; Schwartz, Ilan S; Sigler, Lynne; Kong, Li K; Nelson, Nicholas

    2018-01-01

    Emmonsia-like fungi have rarely been reported from North America. We report a fatal case of E. helica infection in a man with advanced HIV infection from California, USA, who had progressive respiratory failure and a brain abscess.

  11. Eesti ja USA kaitsekoostöö saab uue aluspaberi

    Index Scriptorium Estoniae

    2017-01-01

    Valitsus kiitis eilsel istungil heaks Eesti ja Ameerika Ühendriikide valitsuse kaitsekoostöö kokkuleppe ning volitas kaitseminister Margus Tsahknat allkirjastama selle USA suursaadikuga Eestis. Leppe peab ratifitseerima ka riigikogu

  12. Film teeb USA valmistumise Iraagi okupatsiooniks maatasa / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2007-01-01

    Dokumentaalfilm "Lõppu ei ole näha" ("No End in Sight") : autor ja režissöör professor Charles Ferguson : Ameerika Ühendriigid 2007. Lisa: USA vead Iraagis. Vt. samas: Sunniidid lahkusid Iraagi valitsusest

  13. USA uus ÜRO saadik alustas pealetungi / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2005-01-01

    Ameerika Ühendriikide uus ÜRO suursaadik John Bolton nõuab 190 liikmesriigile saadetud kirjas ÜRO reformikavades suurte ja oluliste muudatuste tegemist: reformikavast peaks USA arvates kustutama vähemalt 400 paragrahvi

  14. Gridded bathymetry of Barbers Point, Oahu Hawaii, USA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (1m) of Barbers Point ship grounding site, Oahu, Hawaii, USA. The data include multibeam bathymetry from the Reson 8101 multibeam sonar collected...

  15. News and Features Updates from USA.gov

    Data.gov (United States)

    General Services Administration — Stay on top of important government news and information with the USA.gov Updates: News and Features RSS feed. We'll update this feed when we add news and featured...

  16. Ämari baas sobib USA-le ja brittidele

    Index Scriptorium Estoniae

    2013-01-01

    Eelmisel nädalal Eestit külastanud USA ja Ühendkuningriigi sõjalised esindajad NATO juures kindralleitnandid David R. Hogg ja Christopher Harper kinnitasid, et on valmis oma lennukeid Ämari baasist opereerima

  17. Reson 8101 Backscatter imagery of Penguin Bank, Molokai, Hawaii, USA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Backscatter imagery extracted from gridded bathymetry of Penguin Bank, Molokai, Hawaii, USA. These data provide almost complete coverage between 0 and 100 meters....

  18. Biochar in the USA. Starting new methods for green energy

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Chris

    2012-07-01

    Companies in the USA develop pyrolysis and gasification systems to generate electricity from biomass and sell the by-product. Up to now it is interesting for agriculture and livestock producers. (orig.)

  19. USA Balti-spetsialist maandus Eestisse / Priit Pullerits

    Index Scriptorium Estoniae

    Pullerits, Priit, 1965-

    2004-01-01

    USA välispoliitika ekspert Paul Goble kavatseb Tartus elades tõmmata oma artiklitega ameeriklaste ja eurooplaste tähelepanu Tartule kui aknale Euraasiasse. Lisa: Välispoliitika ekspert Paul A. Goble

  20. Holocene coastal paleoenvironmental record, Bay of Brest

    Science.gov (United States)

    Fernane, Assia; Gandouin, Emmanuel; Goslin, Jérôme; Penaud, Aurélie; Van Vliet lanoë, Brigitte

    2013-04-01

    Coastal areas are sensitive environments regarding the risk of submersion and the impact on biodiversity induced by salinity changes. These areas thus provide good palaeocecological archives to monitor palaeo sea level changes and the associated adaptation of different biological communities. The north-western coast of France has poorly been investigated regarding its Holocene palaeoecological signatures (Morzadec-Kerfourn, 1974; Naughton et al., 2007). Chironomids have been recognized to be an efficient tool for palaeoclimate and palaeosalinity reconstructions in lakes (Brooks, 2006), and more recently in river floodplains (Gandouin et al, 2006). In this study, environmental changes related to both climate processes and human disturbances, were reconstructed ov