The western half of Quadra Island lies within the Insular belt and is underlain primarily by andesitic volcanics of the Upper Triassic Karmutsen Formation, Vancouver Group. These are interbedded with and overlain to the east by a northwest trending belt of Upper Triassic Quatsino Formation limestone, also of the Vancouver Group.

The eastern half of Quadra Island lies within the Coast Crystalline belt and is mainly underlain by Jurassic to Tertiary intrusive rocks of the Coast Plutonic Complex. These granitic rocks are in fault and/or intrusive contact with the Insular rocks along a northwest trending zone from Open Bay to Granite Bay.

The Lucky Jim deposit is situated 4 kilometres southeast of Granite Bay. Irregular lenticular bodies of limestone occur at inter- vals along a narrow northeast trending zone intercalated with rocks of andesitic composition.

The skarn-type main zone upon which a shaft has been sunk, strikes between 111 and 128 degrees and dips about 80 degrees to the southwest. The ore material follows a prominent line of faulting within the andesite but occurs along the limestone-andesite contact in the shaft area.

The ore material consists almost entirely of pyrrhotite with some chalcopyrite, pyrite and marcasite. At other points along its strike this deposit includes more quartz, epidote, garnet and other silicates, and to the southeast of the shaft a mass of magnetite is exposed. A 0.5 metre sample was taken near the top of the shaft and assayed 8.23 grams per tonne gold and 4.13 per cent copper (Geological Survey of Canada Summary Report 1913). Free gold and sylvanite were also reported (Minister of Mines Annual Report 1908).

The shaft was reported to be down 46 metres with ore still present near the bottom. Drifts are present at the 15 and 30 metre levels with drifts on the latter totalling some 67 metres.

Two parallel zones of mineralization occur 90 metres to the north and 90 metres to the south of the Lucky Jim shaft. All ore deposits in the area occur in the vicinity of limestone.

Over 396 metres of drilling were completed in 1984 by Butler Mountain Minerals Corporation. The resulting indicated reserves were 12,700 tonnes grading 10.97 grams per tonne gold, 17.14 grams per tonne silver and 2 per cent copper (George Cross Newsletter, April 28, 1986).

The Lucky Jim was discovered in 1903 and held by G.D. Mumford. It was later taken over by Great Granite Development Syndicate Ltd.