LA-ICPMS analyses of PGEs in pyrite and Cu-sulfides from Mt. Polley alkalic porphyry Cu-Au deposit, Canada

The Mt. Polley alkalic porphyry Cu-Au deposit has elevated concentrations of Pd and Pt in its Central and Northeast ore zones. Platinum and Pd are primarily hosted in pyrite from the breccia-hosted main stage of mineralization. Low concentrations of Pd and Pt were also identified in main stage chalcopyrite and bornite. We have conducted LA-ICPMS analyses by traditional spot analyses, and have also produced element maps using a new LA-ICPMS technique developed at CODES. These data show that Pd occurs as discrete inclusions primarily in pyrite, but also in chalcopyrite and bornite. Palladium may also occur homogeneously throughout pyrite crystals. Mapping has shown that Pd occurs in growth zones with Te, Ni, Bi, Co and in some cases Au and As, whereas Pt occurs as discrete isolated inclusions with Bi and Te (+/-As). Although Mt. Polley is predominantly mined for Cu, Au and Ag, the relatively high Pd content of its concentrate is encouraging for a Pd by-product.