The Thorne Lake occurrence is located approximately 5 kilometres due east of Thorne Lake about 169 kilometres north-northwest of the community of Germansen Landing.

The showing is hosted in Upper Triassic Savage Mountain Formation (Takla Group) mafic to intermediate volcanics. In this area, the Savage Mountain Formation is bounded to the west by the northwest trending Moose Valley fault and to the east by an Early Jurassic quartz monzodiorite intrusion.

Mineralization consists of chalcopyrite, galena and sphalerite with associated pyrite in a gossanous sulphide zone. Numerous small quartz veins and rusty fracture zones cut silicified mafic to intermediate volcanics near this zone. The volcanics are locally intruded by hornblende porphyry and a lamprophyre dike. The volcanics are fractured and exhibit propylitic alteration. Malachite and azurite staining is common on weathered shears and veins.

In 1984, a grab sample from this sulphide zone assayed 0.179 per cent copper. A grab sample from a mafic volcanic approximately 600 metres to the north assayed 0.35 gram per tonne gold (Assessment Report 13001).