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 “"paleoredox"”.
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The Fate and Mobility of Heavy Metals in East Anglian Salt Marsh Sediments
… to test the effect of diagenesis on these paleoredox proxies. This site is particularly applicable because of an intriguing geochemical dichotomy that exists; the anoxic sedimentary porewater beneath ponds either contains high concentrations of ferrous iron or aqueous sulfide, which are …
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Spatial heterogeneity in isotope and biomarker distributions : insights from the End-Devonian OAE in Western Canada.
… and carbonaceous shales capture changes in paleoredox conditions, water depth, and tectonism over time. Overall, this research contributes to our current understanding of nutrient dynamics and across an ancient anoxic shallow marine basin and factors influencing preservation of biomarkers in …
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Testing the ancient marine redox record from oxygenic photosynthesis to photic zone euxina
… which is implicit in their utility as PZE paleoredox proxies. Results from a modern case study underscore the need to consider allochthonous and microbial mat sources and the role of basin restriction as alternative explanations for these biomarkers in the geologic record, in addition to an …
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Testing the ancient marine redox record from oxygenic photosynthesis to photic zone euxina
… which is implicit in their utility as PZE paleoredox proxies. Results from a modern case study underscore the need to consider allochthonous and microbial mat sources and the role of basin restriction as alternative explanations for these biomarkers in the geologic record, in addition to an …
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Geochemical Characterization of the Utica Shale Play using XRF-Based Chemostratigraphy in Ohio
… in different amounts of terrigenous input. Paleoredox conditions revealed the Farley core was deposited in oxygenated bottom waters which account for the depletion of trace metals throughout the core. In the Tracker core, analysis showed that bottom-water conditions at the time of deposition …
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Source rock potential of the Bakken shales in the Williston Basin, North Dakota and Montana
… Nickel elements are strongly sensitive to the paleoredox conditions of the depositional setting. The location of maximum flooding surface was identified near the top contact of the lower and upper Bakken shales, where the most enrichment of V and Ni occurs. Oil-generation kinetics were also …
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A multiproxy investigation of oceanic redox conditions during the Cambrian SPICE event
… of spatial scales using the iron speciation paleoredox proxy to characterize redox conditions within individual basins and to facilitate comparison of conditions between basins. In addition to these analyses, we apply a new proxy, thallium stable isotopes to this interval to assess potential …
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Investigation of Rhenium's Biogeochemistry
The form of the paleoredox indicator, rhenium, that is sequestered in reducing sediments is not known. To probe this question, I used Laser Ablation ICP-MS to look for correlations between Re signals and those of other elements. My results point to the possibility that Re is incorporated into …
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Organic and inorganic geochemical characterization of the Juana Lopez and Montezuma Valley members of the lower Mancos Shale, Piceance Basin, Colorado
… influxes, grain-size, paleo-productivity, paleoredox conditions, organophillic elements, etc. do closely correlate with paleodepositional conditions. Given the relative lack of available data and the increasing interest in organic-rich units for unconventional plays, additional research to …
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Chromium and uranium isotopic exchange kinetics and isotope fractionation during oxidation of tetravalent uranium by dissolved oxygen
… tools in environmental remediation and paleoredox reconstruction studies. Correctly interpreting Cr and U isotopic compositions in groundwater and sed- imentary rock samples requires thorough understanding of relevant isotope fractionation mechanisms, many of which are still poorly …
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Developing antimony stable isotope methods as a new geochemical redox indicator: computational isotopic fractionation studies
The student, Hannah Shay, submitted this Thesis for approval on 2021-04-21 at 15:54.
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Importance of Sulfide, Polysulfides, and Elemental Sulfur for Abiotic and Biotic Redox Processes in Sulfur-Metal(loid)Systems
… an important indicator for reconstructing paleoredox conditions. However, up to now there is no evidence about thiomolybdate occurrence in the environment. In the laboratory, we found that rate and extent of thiomolybdate formation increased with increasing sulfide to molybdate excess and a …