The Copper Star occurrence covers a small area of copper mineralization immediately south of Courtney Lake, in the historical Aspen Grove copper camp between Merritt and Princeton, where exploration dates back to the turn of the twentieth century. It is centred on one of a number of opencuts and adits, on a hill 200 metres south of Courtney Lake, 500 metres east of Highway 5A and 7 kilometres north-northeast of the community of Aspen Grove.
The occurrence is hosted in the Upper Triassic Nicola Group, which regionally consists of alkalic and calc-alkalic volcanics and intrusions of island arc origin and which is the principal component of the Quesnel terrane in southern British Columbia (Geological Survey of Canada Maps 41-1989, 1713A). This belt has been of major economic interest because of its potential for porphyry copper-gold mineralization.
The Copper Star occurrence is one of many in the Aspen Grove area. It lies in the Central Belt or facies of the Nicola Group (after Preto, Bulletin 69). This belt mainly consists of subaerial and submarine, red or purple to green augite plagioclase porphyritic andesitic and basaltic flows, volcanic breccia and tuff, and minor argillite and limestone. The volcanics are locally intruded by bodies of comagmatic Upper Triassic to Lower Jurassic diorite to monzonite.
The region is characterized by long-lived, primarily north-striking faults and related fracturing, which originally controlled intrusion emplacement. Two important fault systems in the Aspen Grove area—the Kentucky-Alleyne fault and a splay of the Allison fault—converge in the Copper Star area, just south of Courtney Lake. Numerous shear zones that host mineralization, described below, are probably related to these structures.
The Copper Star group of showings is hosted in red and green augite and/or plagioclase porphyritic flows, breccias and tuffs of andesitic or basaltic composition (Assessment Report 17554). The volcanics contain magnetite. The strata strike northwest and dip southwest.
Epidote alteration of the volcanics is pervasive and is commonly accompanied by disseminated jasper or hematite. Alteration is greater in shear fractures, which may also contain quartz and calcite veins as well as jasper and hematite. Epidote alteration, grain size in the volcanics, and copper mineralization all tend to increase from east to west (Assessment Report 17554).
Mineralization is most commonly hosted in the shear zones or in brecciated fracture zones. Here, alteration minerals are accompanied by malachite and pyrite, and smaller amounts of chalcopyrite, bornite, chalcocite and locally minor native copper (Annual Report 1915; Assessment Report 17554; Geological Survey of Canada Memoir 243). Outside the shear zones, there are local concentrations of disseminated chalcopyrite, and up to 10 per cent pyrite in volcanic tuff and breccia.
A number of old trenches, adits and opencuts exist in the area, and are most commonly located on the altered and mineralized shear zones or fractures in augite porphyry volcanics. The various old workings are scattered about an area 200 metres wide and trending northeast for 290 metres.
In 1972, a grab sample from an adit yielded 0.18 per cent copper, whereas a sample from the mineralized shear zone yielded 0.70 per cent copper (Assessment Report 4779).
In 1988, a sample (A-13) of jasperoid with malachite from an opencut yielded 0.288 per cent copper, whereas another sample (A-14) of basalt with epidote and malachite from a test pit to the southeast of the previous sample yielded 0.123 per cent copper (Assessment Report 17554).
Work History
In the early 1900s, a number of opencuts, trenches and at least two adits were developed on the occurrence area. The main adit was driven for approximately 15.4 metres. A small amount of production from the old workings is reported for 1915, when 41 tonnes of hand-sorted ore were shipped to a smelter. According to the returns, this shipment graded 8.7 per cent copper and 75.4 grams per tonne silver (Minister of Mines Annual Report 1915, page 227).
During 1970 through 1972, Tanjo Mines Ltd. completed programs of geological mapping, soil sampling and ground geophysical (induced polarization, self-potential, magnetic and electromagnetic) surveys on the area as the Dor claims.
In 1981, W.G. Timmins Exploration and Development Ltd. completed an airborne magnetic and electromagnetic survey on the area as the DOR, OC, RB and TP claims. In 1983, the Dor claims were staked by P. Peto and in 1986 Tarnex Geoservices completed a 10.2 line-kilometre survey control grid. In 1988, Redding Gold Inc. completed a program of geological mapping, geochemical (rock and soil) sampling and an 18.9 line-kilometre ground magnetic and electromagnetic survey on the Dor property.
In 2001, the Douglas Lake Cattle Co. staked the area and completed a limited program of geological mapping and geochemical sampling in 2002. The claims were re-staked in 2005 and 2006 by R. Billingsley, G. Richards and G. Diakow. In 2007, Etna Resources Inc. completed a 366 line-kilometre airborne geophysical survey on the area as the Aspen Grove property. In 2009, a further program of geological mapping, soil sampling and 48.8 line-kilometres of ground magnetic and induced polarization surveys were completed on the property.
In 2013, New Chris Minerals Ltd. completed a program of rock and soil sampling on the area as the Aspen Grove property on behalf of Richard Billingsley. In 2017, Cazador Explorations Ltd. completed a 145.0 line-kilometre airborne magnetic survey on the property. The following year, an airborne photo geological survey was completed on the area.
