Thin-bedded, argillaceous siltstones and greywackes of the Jurassic to Cretaceous Bowser Lake Group are intruded by a 300 by 800 metre size stock consisting of mainly granodiorite with gradations to quartz monzonite. A 45 to 60 metre hornfels halo extends from the northeast trending stock.

Molybdenite mineralization occurs in the intrusive as selvages along widely spaced, 1.2 to 2.5 centimetre wide milky white quartz veins, as disseminations in aplite stringers, and as coatings on fracture planes with sericite.