The area is underlain by a northwest trending, northeast dipping belt of Upper Paleozoic-Triassic metasediments consisting of horn- blende-biotite schist, quartzites and impure marble. Cretaceous to Tertiary granodiorite of the Coast Plutonic Complex lies west of the metasediments and quartz porphyry and pegmatitic dykes intrude the metasediments.

Clots and small lenses of chalcopyrite, pyrite and pyrrhotite with minor sphalerite, bornite and molybdenite occur in small carbonate-rich zones within hornblende schists and amphibolite. Isolated bodies, up to 2 metres wide and a few metres long, lie along a 1.6 kilometre northwest trend. A 1.2 metre sample of the Young Bull showing assayed 6.2 per cent copper, 1.7 grams per tonne gold and 27.43 grams per tonne silver (Minister of Mines Annual Report 1916, pages 50,51).