The Woss Lake No.4 occurrence is located on the southern side of Torback Creek, approximately 3 kilometres south east of the creek mouth on Woss Lake. It is described as the showing Number 1 in Assessment Report 663.

The region of the Woss Lake occurrence is underlain by a thick sequence of north trending, gently west dipping tholeiitic basalts of the Upper Triassic Vancouver Group, Karmutsen Formation which are in fault contact with andesitic to dacitic basalts and minor sediments of the Lower Jurassic Bonanza Group. Granodiorite of the Late Jurassic Island Plutonic Suite has intruded the older rocks. The presence of a 60 to 90 metre limestone unit interbedded with basalts suggests that the rocks at the occurrence are part of the Bonanza Group.

At the occurrence, amygdaloidal, porphyritic and fine-grained basalts are intruded by a complex of reddish porphyritic monzonite dikes related to a granodiorite batholith one kilometre northeast. The contact zone between the basalts and the granodiorite dips south- west at 26 degrees.

The occurrence consists of lenses of chalcopyrite and pyrite filling fractures and voids in epidote-altered brecciated basalt. The mineralized fractures dip about 35 degrees south. Northwest striking monzonite dikes with strong associated epidote alteration are present.

In 1965, Empire Development completed a program of geological mapping and a dip needle survey on the are as the Woss Lake 1-6 claims. In 1972 and 1973, programs of geological mapping and ground electromagnetic and magnetic surveys were completed. In 1985, Archer Minerals completed a program of rock and soil sampling.