Project: Petrological linkages between Tertiary Porphyry Cu (Mo-Au) deposits in the Cascades, Washington, Vancouver Island and adjacent Coast Mountains, southwest British Columbia
A genetic link between Tertiary porphyry Cu-(Mo-Au) deposits in the Central Cascades of Washington and those on south Vancouver Island has long been suspected. This research investigates the petrology of a number of Tertiary felsic intrusions and associated porphyry-style mineralization in the Pacific Northwest. Specifically, the Catface porphyry Cu (Mo-Au) deposit, located on the central-west coast of Vancouver Island, is examined in detail, and associations to the Cascadian North Fork, and British Columbian O.K. and Gambier Island porphyry Cu deposits are evaluated. A combination of biotite-ilmenite oxybarometry, amphibole-plagioclase thermobarometry, lithogeochemistry, U-Pb geochronology, and Re-Os dating are applied to quantify the oxidation states of the magmas, depths and temperatures of pluton emplacement, magma chemistries, age of the plutons, and timing(s) of mineralization. In addition, geochemical and geochronological data from distinct suites of Eocene magmatism on Vancouver Island studied by Madsen et al. (2004, 2006) will be applied to further define the lithological units at Catface.