The Jack occurrence is located west of Wolf Creek, approximately 13.5 kilometres south west of Nanaimo.

The area is underlain primarily by massive basalts of the Upper Triassic Karmutsen Formation (Vancouver Group) intruded by granodiorite and hornblende diorite of the Jurassic Island Intrusions. Sandstone, pebbly sandstone and conglomerate of the Cretaceous Nanaimo Group unconformably overlies this sequence.

Locally, the occurrence comprises two small outcrops of intensely iron carbonate altered basalt of the Karmutsen Formation. The basalt is brecciated and cut by calcite and occasionally, quartz veins. Carbonate forms the matrix in areas of brecciation. Tetrahedrite blebs (less than 1 per cent) with associated malachite staining occur within the basalt.

In 1987, Chevron Canada Resources completed programs of geological mapping and rock and soil geochemical sampling on the Jack and nearby TEL 1-4 (MINFILE 092F 164) claims. In 1990, T.E. Lisle completed a program of geological mapping and ground electromagnetic and magnetic geophysical surveys.