In this area the geology from northeast to southwest consists of northwest trending Karmutsen Formation andesites and minor limestone, Quatsino Formation limestone, both of the Upper Triassic Vancouver Group, and Lower Jurassic Bonanza Group shales. To the south this succession is in fault contact with Karmutsen Formation rocks.

In the southern block of the Karmutsen Formation, there are many small showings of chalcopyrite, bornite and native copper.