The Barnacle/3060 adit occurrence lies in the Zeballos gold camp which is underlain by the Lower Jurassic Bonanza Group. The Bonanza Group is an island arc sequence consisting of basaltic to rhyolitic volcanic rocks. Conformably underlying the Bonanza Group rocks are limestones and limy clastics of the Quatsino and Parson Bay forma- tions, and Karmutsen Formation tholeiitic basalts, all belonging to the Upper Triassic Vancouver Group. Dioritic to granodioritic plutons of the Zeballos Intrusion phase of the Jurassic Island Plutonic Suite, have intruded all older rocks. The Eocene Zeballos stock, a quartz diorite phase of the Catface Intrusions, is spatially related to the area's gold-quartz veins. Bedded rocks are predomi- nantly northwest striking, southwest dipping, and anticlinally folded about a northwest axis.

The occurrence, 150 metres south-southwest of the Barnacle Ex- tension 1-3 showing (092L 029), consists of a shear zone set with three gouge zones. These are 2.5 to 15 centimetres wide and contain 2.5 to 7.5 centimetre wide vuggy quartz veins that carry coarse gold. The shear zone follows the wall of a 1 metre wide diabase dyke in fine-grained Bonanza Group andesite. The vein strikes 022 degrees and has been explored by an open cut and adit for 10 metres.