Banks Island lies along the western edge of the Coast Plutonic Complex characterized by northwest trending granitic bodies, mainly granodiorite-quartz monzonite and quartz diorite which are separated by narrow, persistent Permian (?) or older metasedimentary belts, mainly crystalline limestone, micaceous quartzite skarn, and schist. The metasedimentary rocks generally exhibit a wide range of "granitization" effects and contact metasomatism.
Regional and local faulting, fracturing, and folding are common on the Island. Two major, right lateral faults, trending 310 degrees known as the Arseno and Hepler faults have associated 045 degree linears. Left lateral faults trending 090 degrees also occur. Many contacts between the plutonic and metasedimentary rocks are faults or drag folds. Some faults have been healed by recrystallization. Structure is the prime factor in ore localization.
The Englishman Zone lies along a major east-west fracture-shear system and is characterized by intense sericite-chlorite-quartz alteration, hosted by biotite quartz monzonite. The Main Zone strikes 115 degrees and dips 80 degrees north and the North Zone strikes 135 degrees and is close to vertical. The two zones are separated by a 20 to 30 metre distinctive hornblende quartz diorite with many intrusive breccia features. Pyrite, pyrrhotite, and arsenopyrite, with minor sphalerite, galena, and molybdenite occur as disseminations.
The east-west trend of the Englishman Zone is displaced by 045 degree cross faults with up to 50 metre left-lateral displacements. The Main Zone strikes 380 metres, has a vertical depth of 90 metres, and widths up to 24 metres. The North Zone strikes a similar length, has a 40 metre vertical depth and widths up to 4 metres. Both zones are open in length and depth.
A 2.44 metre drill intersection in the Main Zone assayed 7.54 grams per tonne gold and 10.29 grams per tonne silver. A 4.0 metre intersection of the North Zone assayed 4.8 grams per tonne gold (Assessment Report 14171).