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Showing 1 to 20 of 37 for “"turbidites"”.
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Lacustrine Turbidites from Tropical African Lakes as Indicators of Hydrologic and Climatic Changes
<p>Flood-sourced turbidites (i.e. hyperpycnites) preserved in lake basins are proven indicators of hydrologic changes, yet their usefulness as recorders of tropical paleoclimate variability has long been overlooked. The primary focus of this dissertation research is to investigate the late …
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Sedimentology and Stratigraphy of a Matrix-Poor to Matrix-Rich Depositional Continuum in Proximal Basin Floor Strata, Upper Kaza Group, Windermere Supergroup, B.C., Canada.
… analyses identified five facies: classic turbidites; sandstones; clayey sandstones; sandy claystones and fine-grained banded couplets, which laterally are arranged systematically from matrix-poor sandstones to thin-bedded turbidites. This lateral change is interpreted to represent a …
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Quantifying channelized submarine depositional systems from bed to basin scale
… seismic data and outcrop exposures to study turbidites at scales ranging from bed to basin. At the basin scale, I develop a method to estimate the time-frame over which sedimentation and subsidence come into equilibrium. Using seismic data from the Fisk Basin, Gulf of Mexico, I find that, …
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Bottom currents and abyssal sedimentation processes south of Iceland
… on 3.5 kHz echo-sounder records). Holocene silty turbidites are locally thick in a sub-marine channel; sandy turbidites and current-winnowed 'sandy contourites' are present in the axis of the major submarine canyon. ‘ Sandy contourite' deposits beneath the axis of the Iceland-Scotland Overflow …
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Quantifying channelized submarine depositional systems from bed to basin scale
… seismic data and outcrop exposures to study turbidites at scales ranging from bed to basin. At the basin scale, I develop a method to estimate the time-frame over which sedimentation and subsidence come into equilibrium. Using seismic data from the Fisk Basin, Gulf of Mexico, I find that, …
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Sedimentology, petrology, and structure of the Moffet Creek Formation, Eastern Klamath Mountains, Northern California
… indicate a coherent succession of folded turbidites that experienced younger thrust faulting. A major flat-lying thrust overlies a northeast-vergent footwall syncline indicating southwest to northeast thrusting. Similar fold vergence in the overlying Gazelle Formation may be the result of …
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Geology and Tectonic Significance of the Late Precambrian Eastern Blue Ridge Cover Sequence in Central Virginia
… are believed to be channelized submarine fan turbidites formed in an anoxic environment. Lynchburg ill consists of fine to medium grained feldspathic quartz arenites and a minor amount of conglomeratic rocks, which are considered to be channelized submarine turbidites with a more open marine …
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Thin-bedded Facies Analysis of a Ferron Storm-dominated Delta Front and Prodelta: Cretaceous Ferron Sandstone, Utah
… river/flood dominated, containing both ignitive turbidites and hyperpycnites. Parasequence 11 is dominated by graded bedding, and shows the highest degree of river/flood dominance with the highest evidence of hyperpycnal deposits seen within the three parasequences. Parasequence 16 is dominated …
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The Carboniferous Courceyan-Chadian) Sedimentary Facies Mosaic of the Keel -Ardagh Area of County Longford, Eire
… oldest rocks are Silurian shales with turbidites. Deposition was in forearc basins in an active subduction zone on the north margin of lapetus.<br/><br/>The area was one of net erosion in the Lower Devonian following the continental collision which closed lapetus. <br/><br/>The Upper …
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Megaturbidites and the late Quaternary regional sedimentology of the eastern and central Mediterranean Sea
… of the many turbidity current deposits (turbidites) noted in the stratigraphy. Radiocarbon dating and geochemical fingerprinting of turbidite muds has allowed construction of an accurate stratigraphy and correlation for the Herodotus Basin, with the recognition of climatically-controlled …
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Geology of an Archean Greenstone Belt at Point Lake, Northwest Territories, Canada
… belt which contains metamorphosed graywacke turbidites, ultramafic and gabbroic rocks, pillow basalts, limestone, shale and tuff. A mylonite zone separates the gneissic terrane from the supracrustal sequence. The mylonite is interpreted to be a basal decollement along which the supracrustal …
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Paleocurrent Analysis of the Cretaceous Mitchell Formation, North-Central Oregon
… fan complex consisting of fan-apron-facies turbidites and mudstones (Hudspeth mudstone facies) and channel-facies conglomerates and sandstones (Gable Creek sandstone-conglomerate facies). Sole marks, flute casts, pebble imbrication, and alignment of plant fragments indicate that sediment …
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ΣΥΜΒΟΛΗ ΣΤΗ ΓΝΩΣΗ ΤΗΣ ΓΕΩΔΥΝΑΜΙΚΗΣ ΕΞΕΛΙΞΗΣ ΚΑΤΑ ΤΟ ΠΕΡΜΟΤΡΙΑΔΙΚΟ ΣΤΟ ΧΩΡΟ ΤΗΣ ΑΝΑΤΟΛΙΚΗΣ ΕΛΛΑΔΑΣ
… ATTICA, C. EUBOEA), CONTINENTAL SLOPES WITH TURBIDITES, OLISTOSTROMES ETC (KAKI VIGLA OF SALAMINA), CALCAREOUS NERITIC PLATFORMS (PTELEOS, HYDRA, CHIOS), AREAS WHICH REMAIN FOR A LONG PERIOD EMERGED (CHIOS ALLOCHTHON FROM M. PERMIAN TO U. TRIASSIC). THE EXISTENCE OF ALL THESE FACIES TOGETHER …
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Interpreting Ancient Climate Signals from Sedimentary Archives of Lake Bosumtwi, Ghana
… interprets temporal and thickness data of lake turbidites observed in scientific drill cores from Lake Bosumtwi, in conjunction with carbon and nitrogen data from organic matter of bulk sediments to assess their climatic implications. A total of 315 layers of flood-induced turbidites …
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GEOCHEMICAL CHARACTERIZATION OF THE BONE SPRING FORMATION, DELAWARE BASIN, USING CHEMOSTRATIGRAPHY AND INTEGRATED PETROPHYSICS
… facies change are manifested by debris flows, turbidites, and slumps. In addition to glacio-eustasy, both tectonism and broader Milankovitch cycles have influenced the depositional history. Previous investigations have utilized cores and wireline logs to provide high-resolution chemo-facies …
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A study of epigenetic mineralisation in the Central Zone of the Damara Orogen, Namibia with special reference to gold, tungsten, tin and rare earth elements
… is hosted by meta-arkoses, marbles and metaturbidites in the magmatic arc (Central Zone; CZ) of the orogen, a tectonostratigraphic entity that is characterised by multiple deformation, greenschist/amphibolite-facies, low-pressure/high-temperature metamorphism and numerous granitic and …
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Turbidity current processes and deposits on the northwest African Margin
… with a total length of 1500 km. Individual turbidites can be correlated across three interconnected deep-water basins, giving an unprecedented insight into the turbidite depositional architecture of a system with complex seafioor topography and multiple sources. A detailed, core-based study …
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Well log petrophysics and re-interpretation of the exploration target intervals in the southern Walvis basin
… petrophysical properties similar to those of turbidites sandstones (e.g. the Murombe-1 Baobab sandstones and the Wingat-1 Cenomanian sandstones). In addition, integration of well log with seismic profiles revealed that the volcanics are lava flows with intercalated sediments. The lava flows …
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Eocene to Miocene geology of southwest Viti Levu, Fiji
… Wainimala Group which includes volcaniclastic turbidites, hemipelagic carbonates and vitric tuffs deposited in the Sigatoka sedimentary basin, and further south volcaniclastic rudites, intrusive/extrusive dacites and andesites, and minor reef/platform limestones representing the Wainimala …
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Paleocene Turbidite Deposition in the Central American Seaway (NW Costa Rica): Geochemical Analysis and Provenance of Detrital Spinel and Clinopyroxene
… of the Paleocene deep water Rivas and Descartes turbidites that crop out on the northern part of the Santa Elena peninsula in northwestern Costa Rica. Understanding the sedimentary fill of the Sandino Basin that contributed to the closing of the seaway may lead to a better understanding of the …
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