The Homestake deposit is located on Homestead Creek, approximately 21.5 kilometres south east of the community of Barriere.
Earliest history of work within the claim area occurred during 1893-1894 when the
exploration interest in the outcropping barite and massive sulphide lenses was initiated.
These mineralized zones would form the nucleus of the Homestake Mine. This led to 2,500 tonnes of production during 1926 and 1927 followed by the erection of a 27 tonne per day mill in 1935. Between 1935 and 1936, 2,700 tonnes of massive sulphides and barite ore were processed. The property was essentially dormant until 1970 when Kamad Silver Ltd. acquired both the crown grants and surrounding mineral claims. Canadian Reserve Oil and Gas acquired the claims in the early 1980’s and completed the development of an 800 metre drift on the 1750 level which was connected to the 2250 level workings by a single raise collared from near the northeast terminus of the 1750 drift. Detailed underground sampling and mapping was carried out and 2,072 metres of underground drilling was completed, along with 2,993 metres of surface drilling. The mine was re-opened during the winter of 1983/1984. Esso Minerals conducted a significant exploration program on these claims from 1986 to 1989. Homestake Canada Ltd. assumed interest in Esso Minerals mineral properties in 1989. In the 1990's, the Kamad and Twin claims were allowed to lapse. In 1999, these claims were re-staked by Eagle Plains Resources Ltd. The claims were optioned to Amarc Resources Ltd. in December of 2004. In 2005, Amarc completed geological mapping programs, lithogeochemical studies and 3,639 metres of NQ diamond drilling in 16 boreholes.
The deposit is hosted by quartz-talc-sericite schists, sericite-quartz phyllite and sericite-chlorite-quartz phyllite derived from felsic to intermediate volcanic rocks (Unit EBA) of the Lower Cambrian and older(?) to Mississippian Eagle Bay Formation. The rocks are overlain by intermediate to felsic volcanic and volcaniclastic rocks (Unit EBF) which hosts the Rea Gold deposit (082M 191), 4 kilometres north. These units are overlain by metasedimentary rocks consisting of argillites, siltstones and grits, which are structurally overlain, to the east by mafic volcanic rocks (Unit EBG) (see Map 56 for unit descriptions).
The deposit lies on the southern limb of a northwest trending, tight, overturned syncline. An east dipping thrust fault is inferred to separate the felsic to intermediate metavolcanics and the more mafic metavolcanics to the east.
Several barite lenses with variable amounts of sulphides occur near the top of a bleached, rusty-yellowish weathered zone of pyritic sericite-quartz schist interpreted to be a highly altered, felsic tuff. The schistosity and compositional layering dip at shallow to moderate angles to the northeast.
The main mineralized areas occur as two tabular horizons separated by 4 to 5 metres of schist. The largest, called the "barite bluff", is 5 to 6 metres wide on surface and contains most of the sulphides. A lower horizon, 1 to 2 metres thick, is banded with only minor sulphides. Underground, the barite-sulphide lenses have been traced several hundred metres.
The main horizon consisting of massive to banded barite, metallic minerals and quartz-sericite are cut by veins and lenses of quartz. The metallic minerals include tetrahedrite, galena, sphalerite, pyrite, chalcopyrite, argentite, native silver and trace ruby silver and native gold. The bayle-basemetal deposit has an extremely large sericite mica envelope.
Several small sulphide lenses, known as the Victory Group, were intersected by old workings at 600, 1700 and 2100 metres respectively, southeast of the Homestake deposit (Property File - Stevenson, 1936b).
Twelve hundred metres northwest of the Homestake deposit, old workings intersected several conformable quartz lenses with pyrite, chalcopyrite, galena and sphalerite. These showings were known as the Silver King and Silver Queen (Minister of Mines Annual Report 1936).
Bands, up to 600 metres wide, of sericite and quartz-sericite extend for up to 7 kilometres from Squaam Bay northwest. The sericite schist is fine-grained, fissile and weathers yellow due to ferric sulphate coating. Nodules of augen-like quartz give the rock a mottled appearance (Z.D. Hora, personal communication, 1990). X-ray diffraction analyses in 1987, by the Ministry of Energy, Mines and Petroleum Resources found talc to be a component in a number of samples of quartz-sericite schist. This deposit is a major potential sericite-mica resource in British Columbia.
Probable reserves are 249,906 tonnes grading 226.6 grams per tonne silver, 36.7 per cent barite, 0.28 per cent copper, 1.24 per cent lead, 2.19 per cent zinc and 0.58 grams per tonne gold (Statement of Material Facts 06/06/86, Kamad Silver Company Ltd.). Caving occurs in unsupported ground. Test milling in 1981 was completed for flow sheet design.
The large sericite envelope of the deposit represents a metamorphosed alteration zone that is of potential interest as a source of mica and may contain substantial reserves of fine-grained muscovite within the sericite schist.