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 5 of 5 for “"Redox proxies"”.
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Geochemical and Paleontological investigations of the Neoproterozoic-Cambrian Transition: Case Studies on geochemical clast provenance, emerging paleo redox proxies, and ambiguous dubiofossils
… sediment sourcing along with changes in marine redox, such as the development of photic zone euxinia. In the third chapter, I investigate the identity of Brooksella alternata, a purportedly cnidarian fossil that was later suggested to be a hexactinellid sponge fossil. My morphological and …
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GEOCHEMICAL ANALYSIS OF THE EAGLE FORD SHALE IN WEBB AND DIMMIT COUNTIES, TX
… mineralogical analysis, and elemental ratio proxies to reconstruct depositional environments and assess controls on detrital influx, paleoproductivity, and redox conditions across multiple cores in Webb and Dimmit counties. Major, trace, and redox-sensitive elements were evaluated alongside …
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From Continental Margins to the Deep Ocean
… is uncertain, making reconstructions of past redox conditions, to better understand the future, essential. For this porpose, redox-sensitive proxies are widely used, but their signals can be altered by depositional and diagenetic processes. In this thesis, we investigate the behavior of these …
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Developing iodine proxies for oceanic oxygenation conditions during greenhouse episodes
… question, exacerbated by a lack of sensitive redox proxies, especially at the interface between oxic and anoxic conditions. To address this problem, I use I/Ca in bulk carbonate and I/TOC in black shale to reconstruct redox changes in the upper and deep waters in multiple ocean basins through …
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Earth’s oceanic oxygen history from Phanerozoic to Pleistocene glacial cycles: insights from the carbonate iodine-to-calcium proxy
… elusive in Earth’s oxygen history, because few redox proxies can track secular variations in dissolved oxygen concentrations around threshold values for metazoan survival in the upper ocean. To address this question, we measured I/Ca in an extensive Phanerozoic collection of shallow marine …