This property is located at 1067 metres elevation on the west slope of Jubilee Mountain about 1.6 kilometres southeast of Ymir.
The Centre Star claim was located in 1900 and Crown-granted to J.S.C. Fraser & associates in 1905. No further activity was reported from the property until 1934. At this time Wesko Exploration and Development Company, Limited, acquired the Centre Star group consisting of the Centre Star, Redman, Twilight, Cold Island, Crowfoot, and Blind Canyon Crown-granted claims, and ten adjoining claims held by location. Exploration and development work was carried on through 1935 and in 1936 a 100 ton per day concentrator was put into operation.
During 1936 the company name was changed to Wesko Mines, Limited. The concentrator operated until August 1938 at which time the ore reserves were exhausted. A very limited diamond drilling program failed to locate additional ore and the mine closed late in the year.
Lessees carried on small scale intermittent salvage operations from 1940 until 1950. The mine has been developed by over 2012 metres of drifts, crosscuts and raises on 5 main levels and several subsidiary levels.
The Centre Star mine is located on the west slope of Jubilee Mountain, about 1.6 kilometres northeast of Ymir. The mine has been developed by over 2000 metres of drifts, crosscuts, and raises on 5 main levels and several secondary levels. Mining operations started in 1936 and by 1938 reserves were exhausted; intermittent salvage operations were carried on from 1940 to 1950.
The area is underlain by Jurassic Ymir Group sediments. The sheared and altered argillites and quartzites are intruded by the Nelson batholith comprising granite and granodiorite of the Middle to Late Jurassic Nelson Intrusions. Prominent shear zones, 5 to 10 metres wide, trending 30 to 55 degrees east with vertical or steep southeast dips, crosscut the host rocks. On the property, two such parallel shear zones occur about 122 metres apart.
Mineralization occurs in a broad contact zone consisting of sheared and altered argillites and quartzite intruded by granite. Ore shoots occur in veins, up to 8 metres wide, along fault fissures striking 280 to 300 degrees and dipping steeply northwest.
The deposit comprises a 152 metre long mineralized vein, dipping steeply northwest, occurs within a 1 to 2-metre wide fracture. The vein strikes 60 to 80 degrees east, diagonally between the two major northeast trending shear zones, and is terminated by shears. Ore shoots with an easterly pitch are developed at the intersection of the vein with northwest trending fractures. The fractures also host sulphides but they contain negligible to zero gold. Tongues of intrusive granite are close to the ore shoots.
Gangue consists of quartz and brecciated, siliceous country rock fragments, with pyrite, galena, sphalerite and pyrrhotite. Pyrrhotite is less common in the upper levels. Near surface, the vein is oxidized with limonite, manganite and pyromorphite stained by cerussite. The average grades from 51,458 tonnes of production were 7.5 grams per tonne gold, 57.3 grams per tonne silver, 1.88 per cent lead and 0.93 per cent zinc (Assessment Report 11753).
