The Union Bay Platinum Prospect, SE Alaska, a Hydrothermal PGE Deposit
- Organization:
- Canadian Institute of Mining, Metallurgy and Petroleum
- Pages:
- 15
- File Size:
- 689 KB
- Publication Date:
- May 1, 2003
Abstract
PGE concentrations of 18 g/t occur in the pyroxene rich rocks at the Union Bay Alaskantype complex. This PGE enrichment is hosted in magnetite veins. These veins cross magmatic layering and have an irregular morphology in both outcrop and thin section. Fe-Ti oxide geothermometry suggests that this mineralization took place between ~700-400°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. Hydrous silicates form an alteration envelope around magnetite veins with a formation temperature of <575oC, vary with temperature, and contain appreciable amounts of Cl. Interaction of a PGE-Fe-Cl rich fluid with clinopyroxene increased the fluids pH and decreased PGE and Fe solubility depositing a PGE enriched magnetite within the Pyroxenites and Olivine Pyroxenites of the Union Bay complex.
Citation
APA: (2003) The Union Bay Platinum Prospect, SE Alaska, a Hydrothermal PGE Deposit
MLA: The Union Bay Platinum Prospect, SE Alaska, a Hydrothermal PGE Deposit. Canadian Institute of Mining, Metallurgy and Petroleum, 2003.