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 pyrrhotite deposit in andesitic rock near granitic intrusive rocks strikes 135 degrees and has a thickness of about 1.8 metres. The ore material extends over the surface, blanket fashion, for 15 metres or more and then suddenly dips down almost vertically.

A 40 metre crosscut tunnel cuts the ore material about 30 metres from the surface. Here, the deposit consists dominantly of pyrrhotite, pyrite and some disseminated chalcopyrite, small amounts of quartz, garnet, epidote, hornblende and associated silicates. One sample taken across the ore material assayed trace gold, nil silver and 0.61 per cent copper (Geological Survey of Canada Summary Report 1913).

A magnetite deposit also occurs nearby. The deposit is from 0.3 to 1.8 metres in thickness and is composed mainly of magnetite, epidote and related silicates.