An extensive, complex shear system occurs in intrusive and gneissic volcanics and metasediments of the Coast Plutonic Complex. Gold associated with pyrite occurs in quartz-ankerite-sericite- sulphide veins.
The Cassie showing is located in the southern part of the north- south trending shear system, about 3700 metres south of the Surf Inlet Mine (103H 027). Two parallel northwest trending quartz veins occur along the contact between diorite and quartz-feldspar-biotite- hornblende gneiss. The contact zone is altered with chlorite, seri- cite, ankerite and quartz. Grab samples from an ore dump assayed 63.0 grams per tonne gold, 93.2 grams per tonne silver and 0.0022 per cent tellurium (Assessment Report 15377).
The zircon date shows that the host is 105 Ma. A previous K/Ar from Dawson is a cooling date of 80 Ma. Thus the mineralization is between 80 and 105 Ma in age.(op cit).