Browsing Electronic Theses and Dissertations by Subject "zircon"
Now showing items 1-8 of 8
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(2015-07-21)Department: Environmental EngineeringTiming and duration of magmatism, involvement of fluid or assimilation of material, and geodynamic context are all important when assessing the processes by which silicic magmas are produced, erupted, or emplaced. This ...
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(2014-07-22)Department: Environmental EngineeringSilicic magmas pose threats to society in the form of explosive volcanism. Understanding silicic magmatism is thus crucial for evaluating eruption-related risks, but numerous questions are unresolved: How are silicic magmas ...
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(2010-07-16)Department: Earth and Environmental SciencesThis two-part study is focused on the evolution of silicic magma in two very different settings. The first part is a study of zircon to understand the generation, storage, and evolution of felsic magmas erupted in historical ...
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(2014-07-22)Department: Environmental EngineeringIceland’s great abundance of silicic rock (10-13% of subaerial exposures), coupled with the unusual thickness of the island’s crust, hints at continental nucleation and permanent crust construction in an oceanic environment. ...
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(2006-07-31)Department: GeologyZirconium and Hf are nearly identical geochemically, and therefore most of the crust maintains near chondritic Zr/Hf ratios of ~35-40. By contrast, many high-silica rhyolites and granites have anomalously low Zr/Hf (15-30). ...
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(2011-04-06)Department: Environmental EngineeringThe processes by which magma is transported into, stored within, and expelled (erupted) from the upper crust are critical to understanding volcanism and crustal construction. Recent studies suggest that magmatic systems ...
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(2011-08-08)Department: Earth and Environmental SciencesThis study aims at understanding the processes by which silicic magmas are generated, how silicic magmatic systems evolve and how they are terminated, and the link between magmatic processes at depth and eruptive centers ...
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(2009-12-08)Department: Earth and Environmental SciencesThis study employs combined U-Th radiometric age and trace element analyses of zircon from rocks of the Swift Creek stage (16 to 10 ka) of Mount St. Helens in order to obtain time-temperature-composition records of the ...