The Van Winkle showing occurs in an area underlain dominantly by metasedimentary rocks of the Harveys Ridge succession of the Snowshoe Group. These rocks comprise black siltstone, phyllite, micaceous quartzite and limestone regionally metamorphosed to greenschist facies.
Mineralization consists of chalcopyrite and pyrrhotite in five quartz veins up to 0.6 metres wide.