The A Chalcocite occurrence is located approximately 8 kilometres west of Sustut Peak about 151 kilometres northwest of the community of Germansen Landing.

The regional geology is similar to that of the Sustut deposit (094D 063) located 4 kilometres north-northeast, and the local geology is similar to that of the A Bornite occurrence (094D 038) located 3 kilometres north.

The occurrence lies within Lower Jurassic Telkwa Formation (Hazelton Group) bedded and lapilli tuffs. A west trending feldspar porphyry sill intrudes these rocks.

Mineralization consists of chalcocite within malachite stained, epidote-calcite-quartz veins, in fracture fillings and in sheared tuffs. The feldspar porphyry sill is associated with the local mineralization and contains minor malachite stained chalcocite-filled fractures. Epidote alteration is commonly found within the country rocks around the larger veins. In 1973, a rock sample from this area assayed 1.5 per cent copper and 22 grams per tonne silver (Assessment Report 4625).

Cross Lake Minerals Ltd. mapped and sampled the Sustut Perimeter property in 1997. A talus float sample assayed 10.59 per cent copper and 215.0 grams per tonne silver (McCrea, J.A. (2011-03-07): Technical Report on the Day Property).