The Tab occurrence is based and located on very meagre information which merely reports sparse chalcopyrite in shale on the Homathko River (Minister of Mines Annual Report 1968). The area lies in the Cadwallader terrane between the Yalakom fault and the northeastern margin of the Jurassic to Tertiary Coast Plutonic Complex (Geological Survey of Canada Open File 1163, Map 1713A).

Assuming the location is approximately accurate, the most likely host rock is shale of the Lower to Middle Jurassic Ladner Group, as this is the closest outcrop shown in the Homathko River Valley (Geological Survey of Canada Open File 1163). In either case, the occurrence lies within 2 kilometres of a large quartz diorite intrusion, probably related to the Cadwallader Plutonic Suite.