The Chalco (092K 016) and Chal 4 (092K 068) occurrences are located approximately 16 kilometres northwest of Campbell River, immediately west of Provincial Highway Number 19.

The area is underlain by a very thick, gently dipping to flat-lying sequence of Upper Triassic Karmutsen Formation volcanic flows. Locally minor interflow sediments occur.

The copper-vanadium minerals occur mainly within lenses of sedimentary rock intercalated with volcanic rocks in a northwest trending shear zone at least 366 metres long. A gently dipping, twisting, pinching seam of mineralized sedimentary rocks lies within brown weathered, dark green, amygdaloidal andesite. The seam is approximately 1 metre thick at its widest point, strikes 315 degrees and dips 45 degrees northeast. It consists of black tuff-argillite overlain by fossiliferous limestone. The black tuff-argillite is heavily stained yellow, green, and blue after chalcocite and volborthite. Malachite, azurite, and bronchantite have also been identified.

The heavily stained black tuff-argillite was analyzed with the following result: 1.8 per cent vanadium, 4.6 per cent iron, less than 0.8 per cent copper, 0.42 per cent titanium, 0.057 per cent manganese, 0.018 per cent chromium and 0.007 per cent nickel (Geological Survey of Canada Economic Geology Number 27, page 54).

In 1955, 5 tonnes of high grade copper ore was shipped to the Tacoma smelter. This produced 1011 kilograms of copper and 249 grams of silver. In 1959, approximately 16 tonnes of sorted ore was trucked to the Cowichan Copper Company Limited dock. The ore averaged 24 per cent copper and was destined for a Japanese smelter (Minister of Mines Annual Report 1959, page 131).

In 1969, Calmac Mines completed a program of rock and soil sampling on the area as the Chal claim group. In 2004, J.W. Laird completed a program of geological mapping on the area as the V 1-10 claims.