The Schaft Creek Porphyry Cu-Mo-Au Deposit

2006

Jeremy Richards, Guillermo Salazar,

The Schaft Creek porphyry Cu-Mo-Au deposit is an unexploited pre-accretionary deposit occurring in Triassic andesites of the Stuhini group of the Stikina terrane in northwestern British Columbia. The deposit lies directly east of two major plutonic bodies which have been dated in previous studies: the ~176Ma quartz-monzonitic Yehiniko batholith of the Three Sisters plutonic suite, and the ~217Ma granodioritic Hickman batholith of the Stikine plutonic suite. Existing age data for the Schaft Creek deposit suggests an age of ~220Ma, indicating a likely genetic association with the Hickman batholith. Copper mineralization throughout the deposit occurs within hydrothermal veins and stockworks as chalcopyrite and bornite. Disseminated sulphides are typically closely spatially associated with vein-hosted mineralization of similar mineralogy. Molybdenum mineralization occurred in two stages, with molybdenite occurring both with copper sulphides in mineralized hydrothermal veins, and later within cross-cutting hydrothermal veins and shear zones. Highly mineralized units include an intrusive igneous breccia which appears to have acted as a fluid conduit for later hydrothermal mineralization due to its elevated permeability, and the “West Breccia Zone” which is a hydrothermal fluid stockwork zone of tourmaline and quartz with significant chalcopyrite and molybdenite.

Keywords: British Columbia, Porphyry, Copper, Schaft Creek