The Inca occurrence is located approximately 6 kilometres northeast of Thorne Lake and 6 kilometres west of the lowermost of the McConnell lakes, about 172 kilometres north-northwest of the community of Germansen Landing.

The occurrence consists of four copper showings with the plotted location centred on a chalcopyrite and bornite showing. Two malachite-stained fracture coatings are located approximately 1 and 2 kilometres northwest of this location and a chalcopyrite showing is located approximately 1 kilometre to the southeast.

The area is underlain by Upper Triassic Savage Mountain Formation (Takla Group) volcanics and Devonian-Permian Asitka Group volcanics and sediments. These rocks are intruded by an Early Jurassic quartz monzodiorite stock. The area lies within a north trending fault slice bounded to the west by the Moose Valley fault and to the east by the Ingenika fault.

Volcanic rocks in the western portion of the property are commonly porphyritic basalts with interfingered tuffs, lapilli tuffs, volcanic breccias and minor flows. The phenocrysts are predominantly augite and feldspar.

The sedimentary rocks on the property are argillites, limestones, cherts and rare conglomerates. Hornfelsed equivalents of the sedimentary and volcanic rocks are found near the contact of the quartz monzodiorite stock and within the intrusive body as pendants. Faults within the property are small and discontinuous. Bedding strikes northwest with variable northeast and southwest dips. Minor tight and broad scale folding is apparent in cliff faces.

Alteration in volcanic rocks is predominantly chloritization with lesser epidotization, silicification, carbonatization and rarely, potassic. The dominant alteration in the sediments is silicification. In intrusive rocks, the alteration is similar to that in the volcanic rocks, with the exception of a more pronounced potassic alteration giving the intrusive rocks a strong pink hue (Assessment Report 19249). The intrusive rocks also exhibit minor sericitic alteration.

Mineralization consists of disseminated chalcopyrite and lesser bornite with associated pyrite within the volcanic rocks. Malachite and azurite staining is common on the fractures. Pyrite is found disseminated and as fracture filling, in all rock types. In 1989, a sample taken from greenstone with malachite and azurite fracture coatings assayed 0.8144 per cent copper and 14.5 grams per tonne silver (Assessment Report 19249).