The occurrence is located on Lead Mountain on the west side of the Rocky Mountain Trench, 9 kilometres northwest of Harrogate which lies within the trench.
The first documented exploration at Lead Mountain occurred in 1904, when ground was staked as the IXL and the Condor claims. In 1919, lead and zinc mineralization was staked as the Rose and Daisy claims. At that time, an adit, elevation 1289 metres, was driven into the top of the mountain. In 1925, another adit, elevation 1259 metres, was driven. In 1926, approximately two tonnes of silver-lead ore were shipped from the Daisy claim. In 1954, Giant Mascot Mines staked the ground and in 1956 drove a third adit, elevation 1198 metres, in which underground work and diamond drilling was done. Underground drilling from the drifts totaled 610 metres. This work was undertaken jointly by Cominco Ltd. and Giant Mascot Mines. In 1966, the property comprised the Tony, Don and Ron groups. During the year, Giant Mascot carried out 137 metres of diamond drilling in three holes. When the claims lapsed in 1966, Cominco Ltd. staked the property as the Mitten claim. Work by Cominco to 1984 included geological mapping, underground sampling and a soil geochemistry programs. The property was staked as the Legacy claims by A.G. Louie in 1993 and is operated by WWC Consulting Ltd.
The region includes strata from the Purcell and Windermere Supergroups, overlain by a Paleozoic platformal carbonate succession. The structure of the area is dominated by the Mount Forster-Steamboat fault, one of a series of Mesozoic thrust faults and it carries folded Middle and Upper Proterozoic strata over folded Upper Proterozoic and Paleozoic strata
While mapping at Lead Mountain, Cominco geologists considered the Upper Cambrian to Middle Ordovician McKay Group to be represented by debris flows, planar laminated mudstones and fine to coarse dolomitized gritstones exhibiting graded bedding and ripples. Here, the Middle to Upper Cambrian Jubilee Formation consists of dense, fine to coarse grained dolomites. The Lower Cambrian Cranbrook Formation, below the Jubilee Formation, consists of pink to white quartzose sandstone, grits and conglomerates.
At the top of Lead Mountain, primarily lead and zinc mineralization occurs in dolomite in an oval shaped area 610 by 245 metres. The mineralization is distributed in a zone 150 to 200 metres long, striking northwest and dipping 75 to 90 degrees southwest. Mineralized outcrops occur at the top of the ridge at an elevation of 1326 metres and on steep northeast cliffs between elevations of 1265 and 1295 metres. Sulphide minerals are associated with barite and include galena, sphalerite, pyrite and chalcopyrite. Mineralization is localized in breccias and tension fractures at the axis of a syncline. The ore, consisting of an intimate mixture of galena and sphalerite carries low silver values and can occur as replacements and impregnations of the limestone in contact with argillites. In places, the ore occurs in bunches and streaks and in others it seems to be disseminated throughout the limestone. The mineralization occurs primarily in the Jubilee Formation.
The following table lists the analyses from four grab samples from Lead Mountain. The analyses are from the Minister of Mines Annual Report 1918, page 153.
_____________________________________________________________________
SAMPLE SILVER LEAD ZINC
grams per tonne per cent per cent
1 92.6 7.8
2 274.3 10.2 24.5
3 137.1 27.5 20.0
4 7.6 4.5
_____________________________________________________________________
