The Thorne Creek occurrence is located on the ridge north of the headwaters of Thorne Creek, approximately 9 kilometres southeast of Thorne Lake, about 162 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 the 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.

Locally, the area is predominantly underlain by basaltic to andesitic augite porphyry flows. These flows typically have an aphanitic groundmass with euhedral augite phenocrysts averaging 3 to 5 millimetres. Lessor fragmental (lapilli tuffs) rocks and feldspar porphyry flows are also present. These rocks are intruded by a hornblende diorite to the southwest. Several monzonite and monzodiorite dikes occur on the property.

Steeply dipping normal and reverse faults are numerous in the area and have a dominant trend to the north (000 to 010 degrees) and to the east (090 to 100 degrees).

Alteration in the volcanic rocks is widespread. The alteration consists of weak pervasive epidotization and chloritization within the rocks and intense pervasive epidotization and potassic alteration along fractures and veins. Potassium feldspar, epidote and pyrite veining is common.

Visible copper mineralization is separated into two zones: Zone A and Zone B. Zone A, 15 metres wide, is the larger of the two and trends east. This zone consists of a shear zone with stringers and pods of semi-massive pyrite hosted in epidote and chlorite altered volcanic flows. Minor pyrrhotite, sphalerite and chalcopyrite also occur with the pyrite. In 1984, a chip sample across this zone assayed 0.1011 per cent copper (Assessment Report 13459).

Zone B lies approximately 900 metres to the east and consists of a north trending pyrite (with minor amounts of chalcopyrite and sphalerite) vein within bleached and silicified feldspar porphyry flows. The pyrite forms discontinuous pods, up to 10 centimetres long and 5 centimetres wide, along an exposed length of 8 metres (Assessment Report 13459). Traces of malachite occur on the fracture surfaces with abundant limonite. In 1984, a chip sample assayed 0.1388 per cent copper and 0.015 gram per tonne gold (Assessment Report 13459).

Similar mineralization occurs in shears and veins within 1 kilometre to the north.

In 2018, Electrum Resource Corporation completed an airborne LiDAR topographic survey and subsequent desktop surficial geological mapping, interpretation and recommendations for geochemical sampling. The survey block over the Thor-Marmot property totals approximately 110 square kilometres (ca. 2018) and covers six occurrences (Thor, 094D 064; Thorne, 094D 126; Thorne Lake, 094D 127; Inca, 094D 129; Thorne Creek, 094D 131; and Marmot, 094D 005). See Marmot (094D 005) for a detailed work history of the area.