The claim is underlain by a northwest trending sequence of volcanic and sedimentary rocks of Upper Jurassic through Lower Cretaceous age mapped as the Fire Lake Group. Argentiferous galena and sphalerite occur disseminated, as breccia fillings and in later stringers and boxworks within some of the stratigraphic units - principally rhyolitic tuffs. Strong gold geochemical values occur spatially associated with an intermediate to rhyolitic tuff near its contact with a black argillite unit.