The Wilds Creek (Leg, Legion, Liz B, Tag) deposit is located at about 915 metres elevation (over a range from 850 to 1250 metres elevation), mainly in the small valley of Wilds Creek that drains southwesterly into Kootenay River between Duck Lake and Wynndel, about 12 kilometres north-northwest of Creston.
The Wilds Creek deposit is one of a series of stratabound zinc-lead-barite prospects and mines in upper Purcell Supergroup stratigraphy along the western edge of the Purcell anticlinorium, typically hosted in dolomitic units of the Dutch Creek Formation near the contact of the overlying Mount Nelson Formation, intercalated with mafic volcanics of the Nicol Creek Formation. All these units are part of the Middle Proterozoic Purcell Supergroup, although the stratigraphic nomenclature and correlation varies with different workers. The rocks are all foliated and structurally complex, with the mineral occurrences lying in the hangingwall (west) of the Hall Lake fault. The occurrences have received various amounts of exploration as illustrated by the Mineral King (082KSE001) about 100 kilometres north of Wilds Creek. It produced 1.21 million tonnes of ore with an average grade of 4.12 per cent zinc, 1.76 per cent lead and 24.8 grams per tonne silver (Minister of Mines Annual Reports 1956 to 1964). Other properties with anomalous lead-zinc-silver geochemistry lie to the north (adjacent Ace or Rob claims: Assessment Reports 12919, 18834).
The first recorded exploration activity on the prospect occurred in 1924 when prospectors trenched and sank two short shafts. The first reported drilling was by Newmont in 1954 when 6 core holes were drilled, intersecting a mineralized zone about 2.0 metres thick with a strike length of approximately 335 metres. Holes S-1 and S-2 intersected greater than 5.0 per cent zinc over about 2.0 metres. Four holes drilled to the northeast of the original zone, holes S-3 to S-6, intersected 1.0 to 2.0-metres thick zones of 2.0 per cent to 4.0 per cent zinc, with up to 0.5 per cent lead. In 1961 the ground was re-staked by Sheep Creek Gold Mines Ltd. Two core holes were drilled to the southwest of the Newmont drilling. Drill hole Liz B-1 intersected 1.52 metres of 14.88 per cent zinc at a depth of 61 metres, and diamond drill hole Liz B-2 was terminated before reaching the zone penetrated in the first hole. The property was briefly examined by Canex later in 1961, and by Cominco in 1962. In 1963 evaluation of the property led to a preliminary reserve estimate. In 1964 the property was optioned to Aspen Grove Copper Mines Ltd., and exploration extended the mineralization approximately 100 metres to the south of the main showing. The entire Main Zone was trenched and 5 drill holes (A-1 to A-5) were completed by the end of 1965. Hole A-4 intersected 9.0 metres of 2.13 per cent zinc. From 1968 to 1970, VLF-EM and ground magnetic surveys were completed over the Main showing. In 1977 Cominco staked adjacent ground and in 1978 conducted a soil survey along Wilds Creek. In 1982 and 1984, Aspen Grove Mines Ltd. extended soil geochemical coverage and in 1988 line-cutting, geological mapping, geochemistry and IP geophysics were conducted. In 1989 Legion Resources Ltd. completed additional line-cutting and ground magnets, followed by diamond drilling (5 holes). From 1990 to 1992 Kokanee Explorations (Quest) completed fourteen diamond drill holes tracing mineralization for about 2.0 kilometres along strike and following the base metals down to a depth of 130 metres. In 1993 Kokanee completed soil geochemical and geophysical surveys, extending the mineralized horizon 3.5 kilometres along strike to the northeast.
The property geology has recently been described in detail by Brown and Klewchuck (Northwest Geology, October 1994; Fieldwork 1994). Two separate carbonate units contain the mineralization, known as the East zone and West zone. The carbonate units are described as dolomite and dolomitic siltstone, hosted in argillite, quartzite and sericite chlorite phyllite; minor mafic volcanics, rarely pillowed basalt, are intercalated. These rocks are intruded nearby by the Duck Lake stock, massive biotite granite (part of the middle Cretaceous Bayonne batholith, and probably responsible for the minor magnetite-epidote-diopside-tungsten-molybdenum skarn mineralization found on the property.
The Main or West mineralized zone is at least 300 metres long by 2 to 3 metres thick as defined by drilling (indicated ore reserves in 1964 of 136,000 to 150,000 tonnes of 6 per cent zinc, with up to 0.5 per cent lead and unspecified silver content, in a block 1.8 by 360 by 61 metres: Assessment Report 22771). It lies within the western dolomitic horizon and comprises at least two intervals of stratabound sulphide-rich material, 30 to 75 per cent pyrite and sphalerite. These intervals are bedding-parallel, fine grained pale yellow to red-brown sphalerite and fine to medium-grained pyrite within laminated baritic dolomite and calcareous quartzite and argillite. The semimassive and layered sulphides form narrow zones less than 25 centimetres thick in the silicic rock; alternating pyrite and sphalerite-rich layers may be a primary structure with a prominent, superimposed penetrative tectonic foliation. Disseminated pyrite is ubiquitous; minor galena occurs sporadically in dolomite layers. At surface, the mineralization is intensely oxidized and poorly exposed; mineralization is banded in the south and becomes more silicified and massive to the north (Assessment Report 19902).
The East zone was explored by drilling in 1989; the best intersection was 0.78 per cent zinc over 0.75 metre (Assessment Report 19902). The East zone is more intensely silicified than the Main zone, with abundant quartz veinlets and stockwork hosted within the eastern dolomitic siltstone unit. Mineralization comprises pyrite with sporadic sphalerite, galena, tetrahedrite and chalcopyrite. Minor silver (up to 23 grams per tonne, with 5.9 per cent lead and 7.1 per cent zinc) is reported over 0.6 metre in the 1992 drilling by Kokanee Explorations.
Irregular patches of pyrite with reaction rims of magnetite and associated narrow intervals of epidote and diopside occur locally in the dolomitic sediments; these patches have associated tungsten and molybdenum (up to 200 and 130 parts per million respectively), and are interpreted to be superimposed calcsilicate hornfels assemblages in the thermal aureole of the Duck Lake stock (Brown and Klewchuck, Fieldwork 1994).
The stratabound main zone at Wilds Creek is foliated and probably remobilized. The two most probable models of ore deposition are sedimentary exhalative (Sedex) or manto replacement. The stratabound zinc-lead-barite mineralization hosted by dolomite lies adjacent to mafic volcanic rocks that thicken rapidly to the north, possibly indicating synvolcanic growth faults developed during rifting. Such block faulting may have provided conduits for a hydrothermal system associated with volcanic activity that could have produced Sedex-style mineralization; the East zone could be a stringer feeder zone.
The Legion property is held by Quest International Resources Corporation (now Standard Mining Corporation) (55 per cent) and Legion Resources Ltd. (45 per cent).