The area is underlain by the Hazelton Group, which is a northwest trending belt of folded volcanic rocks, which contains a thick sedi- mentary sequence infolded along a synclinal axis. This group is bounded on the west by the Coast Crystalline Complex, and on the east by the Bowser Basin.

The host rock is the Texas Creek Batholith of Early Jurassic Age. The mineralization occurs in a series of northwest striking quartz veins in a coarse-grained hornblende granodiorite. Mineralization consists of galena, pyrite, tetrahedrite, sphalerite, and chalco- pyrite. Locally there is considerable barite, and minor amounts of scheelite. A specimen of tetrahedrite, which assayed at 9120.0 grams per tonne silver and 46.4 grams per tonne gold (USGS Bulletin 807, page 75), came from a vein which strikes 125 degrees and dips 75 degrees northeast. This vein, which averages 10 centimetres thick, is likely part of the Olympia Extension vein (104B 164), 600 metres to the southeast.