The Tan 4 showing area is underlain mainly by marine sedimentary and volcanic rocks of the Upper Triassic Stuhini Group, consisting of volcaniclastics, tuffs, tuffaceous breccias, argillites and minor limestone. These are intruded by several small structurally controlled stocks of hornblende diorite to augite porphyry of Triassic or possibly Jurassic age. The rocks are regionally metamorphosed to lower greenschist facies. Faults, with shear directions of 018 to 027 degrees, occur in the area. A diorite stock contains several quartz-carbonate veins, 5 to 35 centimetres wide, with pyrite and chalcopyrite. A sample assayed 19.5 grams per tonne silver, 0.38 gram per tonne gold, 0.03 per cent arsenic (Sample MG-385, Figure 3, Assessment Report 13840).

Work History

In July 1983, the TAN group was staked by Chevron Canada Resources and consisted of the Tan 3 to 6 and SUN 1 claims. This group surrounds the borders of ORO 1 and ORO 5-10 claims which were staked in 1983 prior to the TAN group. Chevron Canada Resources conducted geological mapping and a rock and soil sampling program on their TAN Group, possibly including additional work in 1984 or 1985 (Assessment Reports 11820 and 13840). In 1983, a total of 360 soil samples were collected from the SUN 1 and TAN 5 claims by Chevron Resource in the vicinity of the Oro and Tan showings.

In 1992, a BC Geological Survey geological mapping project in the Tatsamenie and Bearskin lakes area resulted in an updated regional geological framework and the discovery of several new showing including Muse showing (104K 119) just south of the Tan.

In 2019, Brixton Metals Corporation expanded their Thorn property through staking and acquisition of claims including those covering all the Tan showings as well as the Oro and Muse showings. No work is reported on the Tan and Oro showings since their discovery in the earliest 1980s or the Muse showing since discovery in 1992. Refer to Thorn (104K 031), Chivas (104K 180), East Outlaw (104K 083), Oban (104K 168), Trapper (Inlaw) (104K 078) and Metla (104K 161) for details of the work history of the greater Thorn property.

In 2020, Brixton Metals Corporation completed a program of geochemical (rock and soil) sampling, a 12.5 line-kilometre ground induced polarization survey, a 715 line-kilometre airborne magnetic and electromagnetic survey and 19 diamond drill holes, totalling 5292 metres, on the area of as part of the Thorn property. Drilling was performed on the Outlaw (MINFILE 104K 176) occurrence area.

For related geological and expanded work history information refer to the nearby Tan showings (104K 101 and 103), ORO (104K 039), Muse (104K 119), and to Golden Bear mine (104K 079) located about 5 kilometres north.