The Tyee (L.36G) past-producer is located on the western slopes of Mount Sicker, approximately 2 kilometres east of the Chemainus River.

Several past producers are located on Mount Sicker in the Cowichan uplift, one of three geo-anticlinal uplifts that expose rocks of the Paleozoic Sicker and Buttle Lake groups on Vancouver Island. Cretaceous sediments of the Nanaimo Group unconformably overlie the Paleozoic rocks; the contact is marked by a basal conglomerate containing volcanic fragments derived from the Sicker Group. The local stratigraphy is disrupted by folding, faulting (pre-Triassic as well as Paleogene–Neogene) and the intrusions of two gabbro sills (known as the Mount Hall Gabbro) that are coeval with the Upper Triassic Karmutsen Formation. The target of exploration activity has been the volcanogenic, polymetallic massive sulphides that are hosted within felsic volcanic tuffs of the Middle to Upper Devonian McLaughlin Ridge Formation (Sicker Group) and restricted to a belt running from Chipman Creek to Mount Richards, in the hangingwall of the Fulford fault.

Volcanogenic massive sulphides were discovered on Mount Sicker in the late 1800s with production from one main orebody issuing from three independent underground mines (Lenora [MINFILE 092B 001], Tyee [MINFILE 092B 002] and Richard III [MINFILE 092B 003]) for several years. These mines were later amalgamated and operated as the Twin J mine (1942–1952). The massive sulphides are hosted within rhyolitic tuffs and associated sediments of the Middle to Upper Devonian McLaughlin Ridge Formation (Sicker Group). The rocks in the mine include cherty tuffs and graphitic schists which together form a band of folded and/or sheared sediments 30 to 45 metres wide that near the workings are at least 640 metres long. The trend of the band and the strike of the sediments are 110 degrees. The dip of the sediments is 50 degrees southwest. See the Lenora deposit for further details of the geology.

Two types of ore are found in association with the cherty tuffs and graphitic schists: a barite ore consisting of a fine-grained mixture of pyrite, chalcopyrite, sphalerite and a little galena in a gangue of barite, quartz and calcite; and a quartz ore consisting of mainly quartz and chalcopyrite.

The two main orebodies, known as the North orebody and the South orebody, are long, lenticular bodies lying along two main dragfolds in the band of sediments. The North orebody measures approximately 500 metres along strike, 37 metres downdip and from 0.3 to 3 metres in thickness. The South orebody, which is 46 metres from the North, and has its upper limit 45 metres higher, measures 640 metres along the strike, 45 metres downdip and is approximately 6 metres in thickness. Two main faults, striking east and nearly vertical, displace the orebodies. A fracture zone is manifested by vertical silicified zones on the south sides of both the North and South orebodies.

Work History

The area was staked by Harry Smith in 1897 and over the next four years the occurrence was explored and developed with drifts, crosscuts and shafts. During 1902 through 1907, an aerial tramway was constructed to transport ore of the mountain and during this a time a 381-metre long shaft was sunk to develop ore on the 1000-, 1150- and 1250-foot levels.

The Tyee mine was worked intermittently from 1901 to 1909 producing 762 553 grams of gold, 13 725 069 grams of silver and 5 840 593 kilograms of copper from a total of 152 668 tonnes mined (Mineral Policy data).

In 1928, Tyee Holdings was taken over by Pacific Tidewater Mines Ltd. who obtained the lease on the adjacent Lenora (MINFILE 092B 001) mine and an adit was driven from the Lenora towards the Tyee mine. The following year, Pacific Tidewater Mines was taken over by Ladysmith Tidewater Smelters Ltd.

In 1939 and 1940, Sheep Creek Gold Mines Ltd. optioned the Lenora (MINFILE 092B 001), Tyee (MINFILE 092B 002]) and Richard III (MINFILE 092B 003) mines and are reported to have conducted a significant amount of diamond drilling and underground development before the option was dropped due to low zinc prices.

In 1942, the mines were taken over by Twin J Mines Ltd. and over the next two years programs of drilling and sampling, underground rehabilitation and mine site preparation were conducted. Milling began in mid-1943, with operations being suspended in 1944. In 1946, the mining and milling resumed after underground development was re-timbered and continued until September 1947. In 1949, the property was taken over by Vancouver Island Base Metals Ltd., who repaired the Tyee shaft, re-timbered tunnels and continued underground development and diamond drilling. The Mine was re-opened in 1951 with a modest exploration and development program being carried out before closing in January 1952.

The three mines (Lenora [MINFILE 092B 001], Tyee [MINFILE 092B 002] and Richard III [MINFILE 092B 003]) were amalgamated and operated intermittently between 1942 and 1952 as the Twin J mine. See the Lenora (MINFILE 092B 001) mine for the combined production and reserve figures that were derived after the three mines were amalgamated. Zinc, lead and cadmium are also reported in the Twin J production records.

During 1964 through 1966, the area was held and explored by Mt. Sicker Mines Ltd. In 1967 and 1968, Mt. Sicker Mines conducted programs of geological mapping, a 48.0 line-kilometre ground electromagnetic survey and a 3.0 line-kilometre ground magnetic survey on the Mt. Sicker property.

At this time, the Tyee, Upper Lenora and Lower Lenora dumps were estimated to contain approximately 45360 to 136 080 tonnes averaging 0.48 per cent copper; 18 150 to 45 360 tonnes averaging 0.22 per cent copper and an unknown scattered tonnage averaging 0.17 per cent copper, respectively (Assessment Report 1104).

In 1972, Duncanex Resources completed a program of prospecting, line-cutting, geological mapping and a 34.0 line-kilometre ground electromagnetic survey on the surrounding area as the CF Group. In 1974, Dresser Ind. completed four diamond drill holes, totalling 830.0 metres, on the Lenora property. In 1977, John Deighton conducted a geological mapping program on the area as the Yankee, Margie and Mollie claims. During 1978 through 1980, S.E.R.E.M. Limited completed programs of geological mapping, ground geophysical surveys, soil sampling and seven diamond drill holes, totalling 1235.9 metres, on the surrounding area as the Rocky claims.

In 1986, Falconbridge Copper completed a 23.3 line-kilometre induced polarization survey on the area. In 1987, Minnova Inc. completed 16 diamond drill holes, totalling 3217.2 metres, on the Twin property. A single hole (MTS35) was completed on the Tyee claim. No significant mineralization was encountered, with intercepts yielding a maximum of 0.28 per cent copper and 2.2 grams per tonne silver over 1.15 metres (229.00 to 230.15 metres down hole) from a dacitic tuff minor quartz-pyrite-chalcopyrite veins (Assessment Report 16716).

During 1988 through 1990, Minnova completed programs of geochemical sampling and at least 11 diamond drill holes, totalling 3865.8 metres, on the area as the Mount Sicker property. At least five drillholes (MTS-53, -54, -55, -56 and -57) were located south of the Tyee shafts and tested the downdip extent of the Lenora-Tyee massive sulphide zone. The holes were collared in a sequence of andesitic and quartz feldspar porphyry crystal tuffs. A zone of intermediate ashes and cherts that occurs at the contact between a dominantly andesitic package and an underlying felsic tuff package is interpreted as the downdip expression of the massive sulphides. Intercepts included: 0.87 per cent copper and 0.15 gram per tonne gold over 1.00 metre (279.05 to 280.05 metres down hole) in hole MTS-53 and 0.31 per cent copper and 0.32 gam per tonne gold over 0.90 metre (260.00 to 260.90 metres down hole) in hole MTS-57 (Assessment Report 18859).

In 2008, Westridge Resources completed a 440.3 line-kilometre airborne geophysical (magnetic and electromagnetic) survey on the area as part of the Fortuna property. In 2010 and 2011, Rock-Con Resources completed a program of prospecting and rock sampling on the Mount Sicker property. In 2013 and 2014, Conarry Ventures Inc. conducted programs of prospecting and rock sampling on the area as the Mount Sicker property.

In 2020, 911 Mining Co. conducted a program of prospecting and geochemical (rock and silt) sampling on the surrounding area as the Mount Sicker property. In 2021 and 2022, Scenc Resources Corp. completed a minor program of geological mapping, rock sampling, a 1.8 line-kilometre ground electromagnetic survey and four backpack drill holes, totalling 14.9 metres, on the Mount Sicker property. Four samples (one outcrop and three float) from the Tyee occurrence area yielded from 0.48 to 5.43 per cent copper, 0.01 to 1.90 per cent lead, 1.24 to greater than 30.00 per cent zinc, 14 to 173 grams per tonne silver and 0.47 to 4.33 grams per tonne gold (Assessment Report 40298).

Later in 2022, Sasquatch Resources Corp. completed a program of prospecting, geological mapping, drillcore and rock sampling and a 418.2 line-kilometre airborne electromagnetic survey on the Mount Sicker property. Sampling of the previous years drillcores from the Tyee stringer zone yielded 0.26 per cent copper, 3.99 per cent zinc, 9.3 grams per tonne silver and 0.10 gram per tonne gold over 1.35 metres in hole BD22-003 (Assessment Report 41178).