Andesitic and rhyolite flows of the Upper division of the Jurassic Hazelton Group are intruded by granites and granodiorites of the Cretaceous to Tertiary Coast Plutonic Complex. The Hazelton rocks strike east and dip northward at moderate angles. All rocks are cut by Tertiary age diabase dykes and northwest striking slip faults.
The mineralized area is largely confined to hornfelsed green- stones consisting of undifferentiated andesitic tuffs, flows and breccias, which occur above a weakly mineralized cupola of leuco- granite. Molybdenite and lesser chalcopyrite and pyrite occur in fault or fissure-type quartz veins, as disseminations in leuco- granite, and as disseminations in and selvages on quartz or pegmatite veins within hornfelsed greenstone. The main mineralized area measures 1000 by 600 by 350 metres, but grades are very low. Propy- litic alteration consisting of epidote, chlorite, actinolite, pyrite and pyrrhotite is widespread. A series of eleven rock-chip channel samples were taken over 70 metres along a northwest trending fault. The weighted average was 0.036 per cent molybdenum, including a 5.6 metre sample assaying 0.094 per cent molybdenum and 7.5 grams per tonne silver (Assessment Report 8205).