Lasqueti Island is dominated by dark, grey-green amygdaloidal and agglomeratic basalt of the Upper Triassic Vancouver Group, Karmutsen Formation. Regional bedding strikes northwest and dips moderately northeast. The volcanic rocks are locally intruded in the False Bay area by a north-northeast trending stock of the Early to Middle Jurassic Island Plutonic Suite quartz diorite. Narrow shear zones along the stock margins are common and locally contain minor quartz veining. Some hornfelsing of the basalt is also common along the quartz diorite contact but is not significant on a large scale.

Seams of massive sulphide mineralization in the area is often associated with the shear zones along the quartz diorite contact. These zones are narrow, less than 2 metres wide, strike from 010 to 040 degrees and are evident in basalt and quartz diorite.

The St. Joseph occurrence area is 300 metres east of the Venus adits (092F 131) and is underlain by massive and amygdaloidal basalt of the Karmutsen Formation, east of the eastern margin of the Island Intrusions quartz diorite stock. Mineralization occurs as seams of massive chalcopyrite, pyrite and magnetite hosted within 1 to 2 metre wide shear zones. These zones dip vertically, strike from 030 to 035 degrees, are continuous for at least 600 metres and hosted wholly in basalt. The seams of massive sulphide mineralization are often separated by 30 to 50 centimetre wide zones of barren basalt.

Several adits have been developed on the main shear zone. The lower or main adit is just above high tide level on Lot 50 while the upper adit is 185 metres south. The adits are not along strike which may suggest an east striking, right-lateral fault system. Rock samples taken from the adits assayed 5.48 per cent copper and 36.54 grams per tonne gold (George Cross Newsletter #58, 1988). In 1909 and 1937, 44 tonnes of ore was mined producing 498 grams of gold, 1,368 grams of silver and 1,790 kilograms of copper.

Six hundred and fifty metres to the south of the upper St.Joseph adit is the Hill 60 showing which is believed to be the southern extension of the St. Joseph occurrence. A shear zone 0.6 to 1.2 metres wide and up to 274 metres long occurs in basalt and quartz diorite. Samples obtained (1920) from the zone where it crosses quartz diorite assayed 14.4 per cent copper, 13.03 grams per tonne gold and 61.72 grams per tonne silver (Assessment Report 16086).

Past work consists of several adits and some underground development.