Platinum group element enriched hydrothermal magnetite of the Union Bay Alaska-type ultramafic intrusion, Southeast Alaska
dc.contributor.author | Van Treeck, Christopher Jared | |
dc.date.accessioned | 2022-03-18T21:38:49Z | |
dc.date.available | 2022-03-18T21:38:49Z | |
dc.date.issued | 2009-08 | |
dc.identifier.uri | http://hdl.handle.net/11122/12795 | |
dc.description | Thesis (M.S.) University of Alaska Fairbanks, 2009 | en_US |
dc.description.abstract | "The Union Bay Alaskan-type Complex represents a completely different type of platinum group element (PGE) concentration from the classic Alaskan-type Complex PGE mineralization model, with PGEs localized in vein/veinlet magnetite, commonly within the olivine + pyroxene portions of the body. PGE concentrations of 18 g/t occur in magnetite veins and pods which cross magmatic layering and have an irregular morphology in both outcrop and thin section. Fe-Ti oxide geothermometry indicates that this mineralization formed at temperatures between 675-475°C. A variation in the amount of ilmenite and Mg-Al spinel exsolution in magnetite correlates with temperature estimates, lower temperature magnetite has less exsolution. Magnetite veins with a formation temperature of less than 600°C are surrounded by an alteration envelope of hydrous silicates that vary with temperature and contain appreciable amounts of Cl. Interaction of a PGE-Fe-Cl rich fluid with clinopyroxene and olivine increased the fluids pH and decreased PGE and Fe solubility depositing a PGE enriched magnetite within the wehrlite and clinopyroxenite of the Union Bay Alaskan-type complex. Potentially this fluid remobilized the PGE from disseminated euhedral magnetite of the peripheral units to form PGE enriched magnetite veins in the near-central portion of the complex"--Leaf iii | en_US |
dc.description.sponsorship | Pacific North West Capital | en_US |
dc.description.tableofcontents | 1. Introduction, regional geology, and methodology -- 2. Geology of the Union Bay AT -- 3. Geology and geochemistry of the Union Bay PGE prospects -- 4. Petrographic observations -- 5. Mineral analyses -- 6. Discussion, summary, and conclusions -- Future work -- References cited. | en_US |
dc.language.iso | en_US | en_US |
dc.subject | Geochemistry | en_US |
dc.subject | Geology | en_US |
dc.subject | Magnetite | en_US |
dc.subject | Platinum group | en_US |
dc.subject | Ultrabasic rocks | en_US |
dc.subject | Geological intrusions | en_US |
dc.title | Platinum group element enriched hydrothermal magnetite of the Union Bay Alaska-type ultramafic intrusion, Southeast Alaska | en_US |
dc.type | Thesis | en_US |
dc.type.degree | ms | en_US |
dc.identifier.department | Department of Geology and Geophysics | en_US |
refterms.dateFOA | 2022-03-18T21:38:50Z |
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