The Molly occurrence lies close to the contact between Quatsino Formation limestone and Karmutsen Formation basalt, both of the Upper Triassic Vancouver Group.

Minor iron skarn occurs and is comprised of magnetite and chalcopyrite with high cobalt values. A Ministry of Mines sample from a shaft at the showing identified erythrite and assayed 2 per cent copper, 0.16 per cent cobalt and 13 grams per tonne silver (Assessment Report 7843).