Re-Os PYRITE GEOCHRONOLOGY OF THE YELLOWHEAD-TYPE MINERALIZATION, PEND OREILLE MINE, KOOTENAY ARC, METALINE DISTRICT, WASHINGTON

摘要

Pend Oreille, a carbonate-hosted Zn-Pb sulfide deposit, is the only base metal mine recently in production within the historically prolific Kootenay arc belt. The deposit consists of two spatially and lithologically distinct types of stratabound, carbonate-hosted Zn-Pb mineralization: Josephine and Yellowhead. The Yellowhead-type sulfide mineralization, the focus of this study, consists of en échelon tabular to lensoidal pyrite-sphalerite–rich orebodies hosted by the middle Cambrian to Early Ordovician Metaline Formation. The Yellowhead-type mineralization is characterized by carbonate replacement and open-space filling textures, indicating diagenetic and epigenetic origin. As with most low-temperature deposits not directly associated with igneous activity, the timing of sulfide mineralization has traditionally been difficult to constrain using radiometric methods.