Chalco Mine, Menzies Bay, Vancouver Island, Nanaimo Mining Division, British Columbia, Canada
|Latitude & Longitude (WGS84):||50° 8' 25'' North , 125° 25' 1'' West|
|Latitude & Longitude (decimal):||50.1402777778, -125.416944444|
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 brochantite 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).
18 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Late Triassic - Middle Triassic|
201.3 - 247.2 Ma
|Vancouver Group - Karmutsen Formation|
Age: Triassic (201.3 - 247.2 Ma)
Stratigraphic Name: Vancouver Group - Karmutsen Formation
Comments: N.W.D. Massey, P.J. Desjardins, and E.C. Grunsky, 1994, Geological Compilation of Vancouver Island, OF 1994-6, BCGS
Reference: B.C. Geological Survey. British Columbia Digital Geology.