Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"Marine Carbonates"”.
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Petrophysical facies mapping of the Pennsylvanian Cline Shale, Midland Basin, West Texas.
… the distribution of undifferentiated shallow-marine carbonates across the Horseshoe Atoll and borehole washouts. By mapping the petrophysical facies, it was determined that the distribution of the most prospective Organic Rich Shale (ORS) facies, located principally in southwest Howard and …
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Using Nd Isotopes to understand changes in continental weathering flux in Mid-Pennsylvanian (Desmoinesian) carbonate cycles
… relationships between climate change on coeval marine and continental deposits is difficult due to post-depositional erosion and tectonic processes. Nd isotopes measured in marine carbonates are a proxy for regional-scale continental weathering flux (CWF) and can help resolve these difficulties …
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Paleoclimate and mammal paleocology during the paleocene of North America: insights from stable isotopes.
… geographic distribution of mammals. Sedimentary carbonates found throughout exposures of Paleocene terrestrial formations of the Crazy Mountains Basin, south-central Montana are unlike most other non-marine carbonates described previously in the literature, but may have formed under similar …
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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
… the SCZ, predominantly continental and shallow marine Damaran metasediments are floored by a 1.7-2.0 Ga granite gneiss basement inlier, that is transected by numerous ENE-trending aurif erous megashears. These structures controlled late Proterozoic mafic dyke emplacement, Damaran rifting and …
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Chemostratigraphy of the Uppermost Cambrian Below the Ordovician GSSP
… primary carbon isotope signatures in marine carbonates can provide high-resolution profiles for sedimentary sequences supplementing the need for distinguishing fossils from different depositional environments and those lacking fossil materials. The Global Boundary Stratotype Section …
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Lead isotopes as a palaeodietary tracer in southwestern South Africa
… coastal soils contain not only aerosol-derived marine Sr, but frequently also include fragments of shells and other marine carbonates, so their 87Sr/86Sr is like the ocean. This study analysed Pb and Sr concentrations and isotopic compositions of animals and plants derived from the various …
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The geochemistry of carbonate-hosted Pb-Zn-Ag mineralization in the Lavrion District, Attica, Greece: fluid inclusion, stable isotope, and rare earth element studies
… As, and Pb, particularly at Plaka and Kamariza. Carbonates are intergrown with earlier sulfide and sulfosalt mineralization, but are more abundant late in the paragenetic sequence with fluorite and barite. Fluid inclusion studies of sphalerite, fluorite, calcite, and quartz in …
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Carbonate rock-water diagenesis lower cretaceous, Stuart City Trend, South Texas
… shelf-edge buildup of bioclastic and reefal carbonates. This carbonate system is currently buried to depths of between 3,300 and 5,000 meters. Combined with the equivalent updip shallow water, shelf carbonates of the Edwards and Glen Rose Formations, these carbonates form an extensive …
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Marine carbonate accumulation during the greenhouse climate of the Eocene
… links between climate change, carbon cycling and marine carbonate accumulation. Our study finds a strong correlation between magnitude of CIEs and intensity of dissolution for early Eocene hyperthermal events which appears to significantly weaken for multiple dissolution events in middle-late …
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Geochemical investigation of the co-evolution of life and environment in the Neoproterozoic Era
… from prokaryote to eukaryote dominance in marine ecosystems during the Tonian Period (1000 Ma to 720 Ma). To assess whether the availability of nitrate, an important macro-nutrient, played a critical role in this evolutionary event, nitrogen isotope compositions (δ<sup>15</sup>N) of marine …
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Petrogenesis of Pliocene limestones in southern Hawke’s Bay, New Zealand: a contribution to unravelling the sequence stratigraphy and diagenetic pathways of cool-water shelf carbonate facies
… it is now appreciated that shallow-marine carbonates are not restricted to warm-water tropical settings, but can also be produced on modern cool-water shelves outside tropical latitudes. In the last two decades, many publications have not only advanced our knowledge about modern …
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Earth’s oceanic oxygen history from Phanerozoic to Pleistocene glacial cycles: insights from the carbonate iodine-to-calcium proxy
… changes over a range of values where most modern marine animals are sensitive, i.e., at higher oxygen levels rather than euxinia (containing H2S) or anoxia (no O2). Four major projects in my dissertation are:</p> <p>1) Phanerozoic upper ocean oxygenation history and its coevolution with life.</p> …