The area is underlain by Upper Triassic Karmutsen Formation volcanic rocks of the Vancouver Group. These are interbedded with and overlain to the northeast by a northwest trending belt of Quatsino Formation limestone (Vancouver Group) known historically as the "lime-belt". The Vancouver Group rocks are in fault and/or intrusive contact to the northeast with intrusive rocks of the Juro- Cretaceous Coast Plutonic Complex.

A 6 metre wide contact metamorphic zone, enclosed on both sides by andesite, is composed mainly of garnet, epidote, chlorite, hornblende and related silicates. Limestone outcrops within 15 metres and the andesite is intruded by a granitic dyke.

Ore minerals are chiefly limited to a 1.8 metre wide band and consist mainly of pyrrhotite with some chalcopyrite and pyrite. The ore material occurs irregularly distributed throughout the metamorphic zone as particles, lenses and masses which generally follow fractures. Some magnetite is also observed.