Review of Favorable Offshore and Coastal Depositional Sites for Platinum-Group Metals in the Goodnews Bay Mining District, Alaska

摘要

The Bureau of Mines (Bureau) reviewed all available information regarding geologic and depositional processes contributing to potential coastal and offshore platinum group metal (PGM) placer deposits around the Goodnews Bay Mining District. The Bureau found that favorable environments for PGM along with gold and chromite enrichment include: (1) buried paleofluvial channels; (2) recent paleofluvial channels with little marine sediment overburden; (3) beach deposits, particularly in the upper swash zone and near back beach environments; (4) plaeostrand lines; (5) shoal lag deposits inside the mouths of Goodnews and Chagvan Bays; and (6) bases of far offshore tidal ridges which may represent reworked glacial deposits.