General geology and genesis of silver and gold veins in the Beaverdell area, South-central British Columbia

Granodiorite of the Jurassic(?) Westkettle batholith, intruded by stocks of Tertiary quartz monzonite, underlies the Beaverdell Ag-Pb-Zn vein mining camp. Remnants of pendants or screens of metamorphosed sediments and volcanic rocks of the Permian(?) Wallace formation are contained in the granodiorite. Ag vein mineralization is generally within the Westkettle batholith; Au mineralization is commonly found near the contact of Westkettle granodiorite and the Wallace formation. Geological and K/Ar data provide the constraints necessary for a critical examination of models illustrating the derivation of galena-Pb isotope ratios in the Beaverdell region. Three models have been examined, and the most feasible interpretation at present is that veins in the district formed at two distinct times: Jurassic and Tertiary. The differences between the two categories may be significant for exploration.