The Elkhorn occurrence is situated west of Miller Creek on Crown Grant Lot 859 at 1143 metres elevation above sea level, in the Slocan Mining Division.
The Elkhorn claim in 1952 was held under lease from the Crown, by Neil Tattrie, New Denver. The workings are all caved, and the early history is incomplete. First recorded work was in 1895, when a shaft was sunk to a depth of 14 metres, and a tunnel driven 88 metres. In 1907 the property was worked by George Gormley and associates who owned the claim for many years.
Workings, according to Cairnes (1935), consist of 5 adits in addition to a shallow shaft. These adits are referred to by Cairnes, from uppermost to lowest, as Nos. A, B, 1, 2, and 3 respectively. The adits are spaced over a vertical distance of over 61 metres and altogether include about 610 metres of lineal work. Most of the work was done on adits Nos. 2 and 3. In No. 2 adit a strong shear zone was followed for over 61 metres and raises and stopes connect with surface workings 21.3 metres above. The lowest, or No. 3 adit, is a crosscut for about 140 metres to where it is reported to have intersected a fissure, perhaps corresponding to one of the mineralized cross-fissures encountered in the upper workings. The fissure at this depth carries abundant pyrite and considerable sphalerite. In the upper levels the principal ore mineral was galena. The workings in the other 3 adits are not described by either Cairnes (1935) or Hedley (1952).
In 1950 the Elkhorn claim was held under option by Kootenay Belle Gold Mines Limited. During this time the portal of No. 3 adit was reopened and the adit retimbered for about 15 metres before work was abandoned. Some 2750 tonens from No. 2 dump were trucked to the Whitewater mill at Retallack in 1951, but all work ceased in September, when it was found that excessive soluble silica made the zinc concentrate unacceptable at the Trail smelter.
Regionally, the area lies on the western margin of the Kootenay Arc, in allochthonous rocks of the Quesnel Terrane. In the vicinity of the occurrence, the Quesnel Terrane is dominated by the Upper Triassic Slocan Group, a thick sequence of deformed and metamorphosed shale, argillite, siltstone, quartzite and minor limestone. Rocks of the Slocan Group are tightly and disharmonically folded. Early minor folds are tight to isoclinal with moderate east plunging, southeast inclined axial planes and younger folds are open, southwest plunging with subhorizontal axial planes. The sedimentary sequence has been regionally metamorphosed to lower greenschist facies.
South of the occurrence, the Slocan Group has been intruded by the Middle Jurassic Nelson intrusions which comprise at least six texturally and compositionally distinct phases ranging from diorite to lamprophyre. The most dominant phase is a medium to coarse grained potassium feldspar porphyritic granite. Several feldspar porphyritic granodiorite dikes, apparently related to the Nelson intrusions, also cut the sedimentary sequence near the occurrence (Paper 1989-5).
The Elkhorn occurrence consists of a fissure vein hosted by argillite cut by a large sill of quartz porphyry. The strata generally strike north and dip 40 to 60 degrees east. The vein strikes 125 degrees, dips 75 degrees southwest and has been explored with at least five adits and a vertical shaft. Within the workings the vein averaged about 60 centimetres and was continuous for about 60 metres. The productive parts of the shear are at points where it is intersected by mineralized crossfissures striking 065 degrees and dipping 40 to 70 degrees southeast. The vein is vertically zoned. In the upper levels it consists mainly of galena with minor sphalerite, pyrite and chalcopyrite while in the lower level it contains abundant sphalerite and pyrite with lesser chalcopyrite in a gangue of siderite. Galena is argentiferous and gold appears associated with pyrite.
Production from the Elkhorn between 1907 and 1951 yielded 209,883 grams of silver, 55,441 kilograms of lead, 45,032 kilograms of zinc and 93 grams of gold from 2900 tonnes mined. See also New Springfield (082FNW199).
