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 20 of 84 for “"hydrothermal fluids"”.
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XAS studies of metal speciation in hydrothermal fluids
… to elucidate nickel and manganese speciation in hydrothermal chloride solutions, and obtain the thermodynamic properties for predominant species. Ab initio XANES simulation methods were used in this study to provide independent or complementary information about the nature (stoichiometry and …
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Homogeneous equilibria in hydrothermal fluids at near critical conditions.
The activities of aqueous entities in fluids from active hydrothermal systems can provide detailed fluid-mineral equilibria information. Numerical integration of the equations describing homogeneous equilibria as a function of temperature and pressure is the best way to determine ion activities at …
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Geochemical and isotopic characteristics of palaeo-hydrothermal fluids related to granite magmatism, S W England
… investigation into the origin of fluids which characterised the earliest episodes of palӕohydrothermal activity associated with the granites of S W England indicates that the abundance of trace carbon species (CO<sub>2</sub> , CH<sub>4</sub> ) and nitrogen in the fluids was …
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Geochemical tracers of processes affecting the formation of seafloor hydrothermal fluids and deposits in the Manus back-arc basin
… metalloid concentrations) of seafloor vent fluids and related deposits from hydrothermal systems in the Manus back–arc basin (Eastern Manus Basin, EMB and Manus Spreading Center, MSC) are used to investigate processes that affect their formation. Processes responsible for observed …
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Geochemical tracers of processes affecting the formation of seafloor hydrothermal fluids and deposits in the Manus back-arc basin
… metalloid concentrations) of seafloor vent fluids and related deposits from hydrothermal systems in the Manus back-arc basin (Eastern Manus Basin, EMB and Manus Spreading Center, MSC) are used to investigate processes that affect their formation. Processes responsible for observed …
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The geochemistry of boron and lithium in mid -ocean ridge hydrothermal vent fluids
<p>Examining the chemistry of hydrothermal vent fluids can provide insight into processes occurring below the seafloor along the mid-ocean ridge axis. Boron and lithium in hydrothermal vent fluids were studied because previous results indicated that these elements might be useful tracers of …
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The marine biogeochemistry of zinc isotopes
… data on Zn isotopes in anthropogenic materials, hydrothermal fluids and minerals, cultured marine phytoplankton, natural plankton, and seawater. By measuring Zn isotopes in a diverse array of marine samples, we hope to understand how Zn isotopes are fractionated in the oceans and how Zn isotopes …
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The marine biogeochemistry of zinc isotopes
… data on Zn isotopes in anthropogenic materials, hydrothermal fluids and minerals, cultured marine phytoplankton, natural plankton, and seawater. By measuring Zn isotopes in a diverse array of marine samples, we hope to understand how Zn isotopes are fractionated in the oceans and how Zn isotopes …
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The role of gypsum in Cu-Co ore genesis within the Upper Miocene Boleo deposit of the Santa Rosalía Basin, Baja California Sur, México
… fault arrays as feeder zones for metal-enriched hydrothermal fluids, with subsurface gypsum bodies acting as halogen suppliers. These feeders exhibit distinct metal tonnages and ratios, indicating proximity to the source. The dissertation also examines the physicochemical characteristics of …
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Geochemistry of deep-sea hydrothermal vent fluids from the Mid-Cayman Rise, Caribbean Sea
… inorganic, and volatile species distributions in hydrothermal fluids venting at Von Damm and Piccard, two vent fields at the ultraslow spreading Mid-Cayman Rise, Earth’s deepest mid-ocean ridge. In Chapter 2, abiotic organic synthesis is shown to occur via two distinct mechanisms in the …
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Thallium Isotope Implications for the Metalliferous Source of Carlin-type Deposits in northern Nevada
… clastic sedimentary rocks, and (3) magmatic-hydrothermal fluids evolved from magmas. Traditional geochemical and isotopic tracers, including Pb, H, O, S, and C, have yielded ambiguous results, and sources of hydrothermal fluids and their components, especially gold remain enigmatic.Because …
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Laboratory and field-based investigations of subsurface geochemical processes in seafloor hydrothermal systems
… and inorganic chemical composition of seafloor hydrothermal fluids in a variety of geologic settings. Though Chapters 2 through 5 of this thesis are disparate in focus, each represents a novel investigation aimed at furthering our understanding of subsurface geochemical processes affecting …
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Laboratory and field-based investigations of subsurface geochemical processes in seafloor hydrothermal systems
… and inorganic chemical composition of seafloor hydrothermal fluids in a variety of geologic settings. Though Chapters 2 through 5 of this thesis are disparate in focus, each represents a novel investigation aimed at furthering our understanding of subsurface geochemical processes affecting …
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Diagenetic controls on porosity, thermal history, and hydrocarbons in the Wolfcamp A, eastern Midland Basin, Texas
… of the Th record indicate tectonic valving of hydrothermal fluids. Relatively non-radiogenic 87Sr/86Sr for high temperature cements (0.707464 – 0.707846) suggest a fluid origin from a sedimentary basin rather than basement. The most likely source for the hydrothermal fluids is the much deeper …
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Geochemical Analysis of Mississippian Cherts and Devonian-Mississippian Novaculites, Southern Midcontinent Region
… the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb …
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Geology and geochemistry of the Bully Hill area of the East Shasta district, Shasta County, California.
… replacement by barite. ΣSO₄⁼ and H₂S contents of hydrothermal fluids decreased from Stages 2a to 3a. δ³⁴S values of sulfides increased successively from Stages 1 (-15.8 per mil) to 3a (3.0 per mil), reflecting variable inputs of biogenic sulfur and deep-seated fluid evolution. δ³⁴S values of …
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Geochemistry of a volcanic hydrothermal system at Mount Spurr, Alaska
… research aims to characterize more fully the hydrothermal system and builds on published geological mapping, geophysical surveys, soil sampling, exploration drilling, and water sampling. Aqueous and mineralogical geochemical investigations at a field area on the south flank of Mt. Spurr focus …
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Winning Silver
… base on theoretical and experimental studies of fluids properties, mineral phase equilibrium, physical and chemical mechanisms. Making the technique highly transportable so that it can be applied in the field during an exploration program base on petrographic characteristics of mineral textures …
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Geochemistry of deep-sea hydrothermal vent fluids from the Mid-Cayman Rise, Caribbean Sea
… inorganic, and volatile species distributions in hydrothermal fluids venting at Von Damm and Piccard, two recently discovered vent fields at the ultra slow spreading Mid-Cayman Rise, Earth's deepest mid-ocean ridge. A wide variety of possible temperatures and substrates for fluid/rock reaction …
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