Discontinuous pyrite-galena-carbonate-quartz veins, up to four centimetres thick, are hosted in Upper Triassic Stuhini Group volcanic breccia. Also irregular iron-carbonate-pyrite-quartz veins, up to five centimetres wide, occur in augite-bearing volcanic breccia. Narrow zones (less than 15 centimetres wide) of buff weathering, clay-altered wallrock extend beyond the veins.

The "Strata Mountain Pluton", a hornblende quartz monzodiorite body, believed to be Middle Jurassic age, intrudes the Stuhini Group immediately west of the veins.