The island is composed of diorite, granodiorite and quartz diorite of the Jurassic to Cretaceous Coast Plutonic Complex. Shear zones crosscut the island in a southwest direction. Fine minerali- zation in the form of pyrite is found disseminated throughout, but most concentrated in the shear zones. Molybdenite is recorded as being found on the island, but later exploration was unable to locate it (Minister of Mines Annual Report 1968, page 73; Assessment Report 3446).

Showing Number Two is 1.5 metres wide, trends 260 degrees with 50 degrees north dip and occurs on the extremely irregular hangingwall contact of a feldspathic dyke. The host is medium to coarse-grained and most likely gabbroic in composition, with an abundance of epi- dote and chlorite. The mineralization consists of coarsely dis- seminated sphalerite, galena and minor chalcopyrite. A small sample assayed 1.01 per cent zinc, 0.44 per cent lead and 0.06 per cent copper (Assessment Report 3446).