The area around Brucejack Lake, near the headwaters of Sulphurets Creek, is underlain by Upper Triassic-Middle Jurassic Hazelton Group rocks comprised mainly of crystal and lithic tuffs, minor chert, greywacke and limestone.

The Brucejack Peninsula can be divided into three areas by faults. The northern and central area are elongate fault blocks which trend about 120 degrees. A silicified zone in arkose occurs between and parallel to faults which are at 45 degrees to the Brucejack fault. The northern area has an intensely silicified zone with low gold and silver values along its axis, near the northeast shore of the peninsula. The central area consists of arkose with only minor quartz veining. The southern area, or Discovery zone, consists of arkose, arenite and tuffs with ubiquitous silicification, sericitization and veining.

An intensely shattered quartz vein striking 050 degrees and dipping 75 degrees north was located in 1980. This vein is impregnated with argentite and electrum. A sample taken over 1.0 metre assayed 1028.6 grams per tonne gold and 22,765 grams per tonne silver. In 1982, a silicified mass adjacent to the discovery site was trenched. Values were low, except for a 3.0 metre section from Trench 2, which assayed 8.57 grams per tonne gold and 814.27 grams per tonne silver (Bridge and Melnyk, 1982). The Discovery vein is located about 10 metres south of a barite vein. This barite occurrence is thought to be the Luck occurrence which was located in 1935. A sample of this quartz-barite vein, taken from Trench 6 which is located about 45 metres northwest of Trench 2, assayed 4.11 grams per tonne gold and 238.28 grams per tonne silver over 2.0 metres. Another 1.5 metre sample taken from Trench 1 assayed 3.42 grams per tonne gold and 87.43 grams per tonne silver (Bridge and Melnyk, 1982).

The Windy Point zone was discovered in 1993. The zone consists of a quartz vein/stockwork structure up to 9.5 metres wide and 250 metres long. It trends northwest, dips vertically, and appears to merge with the Trachsel zone (104B 386) at its northwest end. Mineralization consists of disseminated and fracture fill pyrite with minor amounts of arsenopyrite, tennantite, tetrahedrite, sphalerite and galena. Significant trench results were 2.1 grams per tonne gold and 167.2 grams per tonne silver across 0.55 metre (Assessment Report 24610, page 19).

Refer to West (104B 193) for details of related mineralization and work history.