The Raven occurrence is underlain by amygdaloidal basalt of the Upper Triassic Karmutsen Formation (Vancouver Group). A narrow band of diorite and quartz monzonite outcrops south and north respective- ly, of Raven Bay.

Massive magnetite lenses containing pyrite and minor chalcopy- rite are irregularly distributed in a fracture zone in basalt. The zone is 0.3 to 2.4 metres wide and traceable for 45 metres along strike. Locally, a band of chalcopyrite 2 to 38 centimetres wide is found within the magnetite. Minor garnet occurs with the magnetite and erythrite is also present.

A shaft and two drifts exploited the magnetite lenses. Histor- ically, a considerable amount of material was stoped out and shipped as a flux (Geological Survey of Canada Memoir 58, page 67).