The Grey Mask shaft is located on the west side and adjacent to Highway 5A, south of Separation Lake, about 10 kilometres south of Kamloops. The shaft explores a north trending shear zone in microdiorite of the Late Triassic-Early Jurassic Iron Mask batholith. The shear zone is mineralized with chalcopyrite, specular hematite, pyrite and some native copper. Occasional magnetite veinlets and malachite were noted and sparse disseminated native copper also occurs in sheared diorite outside the mineralized shear zone.
In 1994, drilling south of the shaft intersected weak to strongly potassic, epidote, carbonate and hematite altered diorite breccias. Mineralization consisted of narrow zones/bands of massive specular hematite with local 1-3 per cent fracture-controlled chalcopyrite. Mineralized intervals containing greater than 0.5 per cent copper were generally narrow with the best results of 1.1 per cent copper and 3.28 grams per tonne gold over 2.35 metres (Assessment Report 23894). The bottom of drillholes JK-94-03, 4 and possibly 5 intersected non-mineralized andesitic volcanics of the Upper Triassic Nicola Group in fault contact with the overlying diorite breccias (Assessment Report 23894).
The principal working is a shaft stated to be 8.5 metres deep, with a drift 12 metres to the south at the bottom. The working was inaccessible in the early 1940s. Similar mineralization in diorite was found in a well 42 metres to the southwest of the shaft and consisted of some coarsely intergrown calcite and specular hematite with chalcopyrite and quartz. A filled-in opencut is located between the well and shaft. Another caved shaft is located about 200 metres south of the Grey Mask shaft (Assessment Report 6717). In 1956, Commercial Minerals Limited conducted some diamond drilling in the Grey Mask shaft area. Two drillholes intersected 38 metres grading 0.18 per cent copper and 32 metres grading 0.27 per cent copper, respectively (Report by L.G. Phelan, 1967).
The Grey Mask group was staked by J. Surina but work on the claims has been abandoned and believed to be lapsed (ca. early 1940s). In 1956, eight short diamond-drill holes totalling 398 metres were drilled by Commercial Minerals Limited in the immediate vicinity of the filled-in Grey Mask shaft. In 1965, Mineral Mountain Mines Ltd. completed 18 kilometres of ground magnetometer survey and 13.1 kilometres of VLF-EM survey on the Bee claim group. In 1966, Fidelity Mining Investments Ltd. conducted a 21 kilometre induced polarization survey over the Pinnacle claim group which also covered the And (092INE124), Joker (092INE015) and Grey Mask showings. In 1968, Pinnacle Mines Limited took 1785 soil samples over the A, C, Cle and Pin claims which covered the And, Grey Mask and Joker showings. In 1972, geological mapping, soil sampling and 15.9 kilometres of ground magnetometer survey was completed on the large holding of JD claims on behalf of Flagstone Mines Ltd. The JD claims cover the Joker, Grey Mask and And showings. In 1977, Cominco Ltd. conducted geological mapping and rock sampling on the Lark claims which cover the Joker and Grey Mask showings. In 1978, Cominco Ltd. completed 6.5 kilometres of induced polarization and ground magnetometer survey on the And and Lark claims. In 1994, Teck Corporation completed six diamond-drill holes totalling 690.7 metres, 21 kilometres of VLF-EM and ground magnetometer surveys, geological mapping and soil sampling (389) on the Joke and Ace claims which cover the Joker, Grey Mask and Phil showings.
