The general area is primarily underlain by Mesozoic Skeena Group rocks consisting of basaltic lava flows, tuff breccia, flow-banded rhyolite lava, chert and argillite. Rhyolite dikes and sills in the area have been dated (potassium-argon: 76.5 +/- 3 Ma) as Upper Cretaceous. The Skeena Group rocks are intruded by an Eocene Nanika Intrusion comprised of quartz monzonite and porphyritic monzonite.

The Summit showing consists of mineralized amygdaloidal basalt which is locally hornfelsed. Fractures and amygdules are filled with quartz, calcite, amphibole and concentrations of pyrrhotite, molybdenite, minor pyrite and chalcopyrite. The Summit showing and the Grubstake showing (093L 003) have been explored as part of the same property.