The C Extension occurrence is located on west facing slopes, east of the Malksope River.

The region is underlain by Lower Jurassic Bonanza Group intermediate to felsic flows and pyroclastics. Minor calcareous sediments of the Upper Triassic Parson Bay and Quatsino formations of the Vancouver Group are in fault contact with the volcanic rocks. A diorite stock of the Jurassic Island Plutonic Suite. occurs at the head of Kashutl Inlet, 5 kilometres to the northeast.

Locally, pyritic, clay-altered and silicified mafic volcanic rocks of the Karmutsen Formation are exposed over at least 300 metres. Pyrite mostly occurs as fine-grained disseminations up to 5 per cent; it occurs less commonly as blebs and fracture fillings. The southern margin of the zone is flanked by a halo of propylitic alteration approximately 25 metres wide. The northern margin of the zone is not exposed. Quartz-carbonate-sulphide veins occur throughout the zone. The veins are generally less than 5 centimetres wide, but range up to 20 centimetres. Some are locally vuggy. Sulphides include sphalerite with lesser pyrite and chalcopyrite, and, rarely, galena.

In 1989, grab samples of vein material yielded up to 0.81 gram per tonne gold, 4.1 grams per tonne silver, 0.141 per cent copper, 1.07 per cent zinc and 0.35 per cent lead (Assessment Report 19462).

Work History

In 1982, BP Minerals Ltd. completed a program of geological mapping and rock sampling on the area as the Sin 1-7 claims. During 1986 through 1990, Taywin Resources completed programs of geological mapping, geochemical sampling, trenching and eight diamond drill holes, totalling 304.9 metres, on the area as the Sin 1-7 claims.