Drilling discovered that the claims are underlain by a Jurassic Topley Intrusion comprised of granodiorite. Younger, highly magnetic, Tertiary Endako Group volcanics are exposed along Redtop Creek. The volcanics consist of Oligocene vesicular basalt and basaltic breccia of the China Nose Breccias (GSC Map 351).

The Topley granitic rocks contain pyrite, chalcopyrite and molybdenite. Where they are relatively unaltered, the rock is fine-grained granodiorite which is light grey in colour and consists of quartz, plagioclase with incipient sericite alteration, potassic feldspar, hornblende altered to green biotite, and primary biotite altered to chlorite. Better grades of mineralization occur in the intensely altered varieties of granodiorite which are buff coloured and consist essentially of quartz, sericite, and carbonate.

The chalcopyrite, molybdenite, and pyrite commonly occur as selvages or disseminations in 0.3 to 0.6 centimetre quartz veinlets which are rimmed by secondary potassic-feldspar.

Approximately 30 metres of glacial drift overlies the minera- lized zone.