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 within the shear zone.

The Bonanza showing is located in the southern part of the north-south trending shear system, about 2700 metres south of the Surf Inlet Mine (103H 027). Two parallel north-northwest trending quartz veins occur along the contact between diorite and quartz- feldspar-biotite-hornblende gneiss. The contact zone is altered with chlorite, sericite, ankerite and quartz. A 1.2 metre sample across a quartz vein assayed 12.8 grams per tonne gold, 86.0 grams per tonne silver, 1.72 per cent copper and 0.0033 grams per tonne tellurium (Assessment Report 15377).