The CT South (South Ridge) occurrence is located on a north-south–trending ridge, west of the Ospika River and approximately 20.5 kilometres south-southwest of Sikanni Chief Lake.
Regionally, the area is underlain by a thick succession of Ordovician to Devonian Road River Group rocks consisting of black graphitic-graptolitic shales, black pyritic mudstones, dolomites, arenite (siltstone) turbidites and mafic volcanic flows.
Locally, mineralization forms a discreet stratigraphic horizon within the upper portion of this package. Overlain by a finely laminated baritic siltstone, the mineralization consists of a massive pyrite and sphalerite base, dolomite-pyrite-sphalerite breccia in the centre and massive barite and sphalerite at the top. Underlying this zone is dolomite with quartz-carbonate veins containing minor galena and sphalerite. This zone overlies a mudstone with 1-centimetre-wide sphalerite and 10-centimetre-wide pyrite lenses. Beneath the mudstone, dolomite hosts barite veins and sphalerite-galena–bearing quartz-carbonate veins. The whole sequence, from the top of the mineralized zone to the bottom of the dolomite, varies from 15 to 24 metres in thickness. Other mineralized zones, referred to as the Cut (MINFILE 094F 010), Heavy Oxide, Main Ridge, West and North Ridge zones, have been traced over a strike length of approximately 2.5 kilometres.
In 1980, a chip sample from the South Ridge zone yielded 4.5 per cent zinc over 6 metres, including 8.2 per cent zinc over 2 metres, whereas another chip sample, located approximately 250 metres to the northwest of the South Ridge zone, yielded 6.4 per cent zinc over 2 metres (Assessment Report 9243).
Work History
During 1980 through 1983, Cominco Ltd. completed programs of geological mapping, geochemical (rock, silt and soil) sampling and minor trenching on the area as the CT claims. In 1996, Cominco completed one diamond drill hole, totalling 319.5 metres on the Cut zone of the CT property.
In 2007, Rio Grande Mining Corp. conducted a program of geochemical sampling, gravity geophysical surveys, prospecting and geological mapping on the area as part of the Kechika property. The following year, Rio Grande completed an airborne magnetic survey on the area.
