Several shear zones occur in chloritic Upper Triassic Karmutsen Formation (Vancouver Group) basalt, basaltic agglomerate and amygdaloidal basalt. Numerous quartz-carbonate alteration zones are developed along or adjacent to these structures.

The Cisco occurrence comprises a northwest trending, pyritic quartz-carbonate (ankerite) shear zone within chloritic basalt and basaltic agglomerate. Some chalcopyrite has been identified within this zone. A rock sample assayed up to 1.35 grams per tonne gold (Assessment Report 16013).