This occurrence is underlain by undifferentiated volcanic and sedimentary rocks of the Upper Triassic Stuhini Group. In this area they are mainly andesitic and basaltic flows, tuffs and breccias with minor interbedded sediments consisting of siltstone, mudstone, limestone and conglomerate. Plugs of granodiorite and quartz monzonite along with Juro-Triassic stocks and dykes of syenite and tabular bodies of rhyolite also intrude these rocks. Younger dykes of diorite or monzonite intrude all other rock types.

A mineralized area above Strata Creek occurs in andesitic volcanics that are cut by syenite, rhyolite and diorite dykes. Float pieces below the rock bluffs carry zoned veins of massive chalcopyrite with pyrite rims. Near the top of the ridge at least two narrow veins of chalcopyrite occur. The chalcopyrite is less than 15 centimetres across. The sulphide veins and the syenite dykes have the same 20 degree strike and there appears to be some relation- ship between them. No values were reported from rocks sampled at this occurrence.