The CM (Snowflake Gold Zone) occurrence is a prospect of copper-gold-silver mineralization in part of 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 a diamond drill hole that intersected significant mineralization in 1983; this hole was later discovered to be only 40 metres away from the 1967 diamond drill hole that discovered the mineralized zone when it was part of the CM claims (Assessment Reports 12113, 14983, 17523; George Cross News Letter 1967). The occurrence is located 2.3 kilometres east of Highway 5A and approximately 6 kilometres north of the community of Aspen Grove.
The occurrence is hosted in the Upper Triassic Nicola Group, which regionally consists of alkalic and calcalkalic 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 CM 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). These rocks mainly consist of subaerial and submarine, red or purple to green augite plagioclase porphyritic andesitic and basaltic flows, volcanic breccia and tuff, and minor argillites and limestone. Locally the strata strike north or northwest and dip gently to steeply west. The volcanics are intruded by bodies of comagmatic Upper Triassic to Lower Jurassic diorite to monzonite. The area is characterized by long-lived, primarily north-striking faults and related fracturing, which originally controlled intrusion emplacement. East-striking faults are subordinate, and commonly offset intrusive contacts.
The area of the CM occurrence has been called the Snowflake Gold zone or area (Area 4 in Assessment Report 13714). This is a thinly bedded volcanic-sedimentary sequence consisting of a composite unit of dark grey to black, carbonaceous, pyritic calcareous argillite or impure limestone, greywacke, chert and siltstone, which is overlain and underlain, possibly structurally, by andesitic to basaltic augite porphyry flows, tuffs and breccias (Assessment Reports 12113, 13714). The volcanics are weakly to moderately propylitized, and marked by epidote, calcite, quartz and pyrite (Assessment Report 12113). The sequence is cut by a number of faults and shear zones. The Snowflake Gold zone is marked by a strong induced polarization conductor (Assessment Report 14983).
Outcrop in the Snowflake Gold zone is virtually absent, so detailed information is based on drillcore (Assessment Reports 12113, 14983, 17523, 18019). A zone of silicification and pyritic and argillic alteration, tens of metres wide, straddles the contacts between the volcanic and sedimentary rocks, particularly the lower contact. In this alteration zone are fracture-controlled quartz and quartz-calcite veins, 1 to 6 centimetres thick, that host pyrite, chalcopyrite, and malachite; gold and silver, mainly as electrum, are associated with these sulphides (Assessment Reports 12113, 13714, 14983). Galena, sphalerite, bornite, molybdenite and argentite are less commonly associated (Assessment Reports 12113, 17523). The rocks also contain pyrite and pyrrhotite as fine disseminations and locally as massive lenses up to 0.3 metre across (Assessment Report 13714).
Overall, rock analyses indicate that higher gold values occur in the thinly bedded, cherty and argillaceous sediments, although there are also high values locally in the volcanics away from the altered contact zone. Gold and silver values in drillcore are generally low, although the better intersections, such as in hole 83-8, are in the range of 1 to 10 grams per tonne for each metal (Assessment Report 12113). More recent diamond drilling done in the late 1980s further defined the zone and controls of mineralization, although the high-grade values are generally erratic (Assessment Reports 17523, 18019).
In 1967, a diamond drill hole (DDH 1) yielded intercepts of 4.5, 5.1 and 3.9 grams per tonne gold, 39.3, 16.4 and 57.5 grams per tonne silver with 0.70, 0.20 and 0.26 per cent copper over 3.0, 18.0 and 3.0 metres (49.5 to 52.5, 63.0 to 81.0 and 93.0 to 96.0 metres down hole), respectively (Assessment Report 13714, page 4).
In 1983, drilling yielded up to 4.9 grams per tonne gold over 11.2 metres (39.6 to 51.8 metres down hole), including 35.9 grams per tonne gold, 411 grams per tonne silver and 0.29 per cent copper over a 1.4 metre interval (42.6 to 44.0 metres down hole) of pyritic argillite in hole 83-8 (Assessment Report 12113).
In 1986, a drillhole (86-5) on a zone of veined and altered volcanics, located approximately 200 metres south of the previous drillholes, assayed 4.49 grams per tonne gold, 21.94 grams per tonne silver and 2.1 per cent copper over 2 metres (84 to 86 metres down hole) of quartz-pyrite-chalcopyrite veining cutting volcanic conglomerate below the carbonaceous shale (Assessment Report 14983).
In 1987, diamond drilling yielded intercepts of up to 21.30 grams per tonne gold and 34.0 grams per tonne silver over 1.5 metres (36.0 to 37.5 metres down hole) and 6.83 grams per tonne gold with 17.5 grams per tonne silver over 1.50 metres (43.5 to 45.0 metres down hole) in hole 87-3, located near previous drillhole 83-8, while drilling approximately 200 metres to the south-southeast and in the area of the previous drillhole 86-5 yielded anomalous results of up to 0.25 gram per tonne gold over 16.5 metres (51.0 to 67.5 metres down hole) in hole 87-9 and 0.45 gram per tonne gold over 4.5 metres (75.0 to 79.5 metres down hole) in hole 87-10 (Assessment Report 17523).
Work History
The occurrence was first discovered in 1965 by Vananda Explorations Ltd. In 1967, Merritt Copper Company Ltd. completed ground magnetometer and induced polarization surveys and, later that year, three diamond-drill holes, totalling 438 metres, and one percussion hole, 248 metres deep, to test a geophysical anomaly. In 1979, Cominco Ltd. completed a 26.0 line-kilometre ground magnetic and induced polarization survey on the area as the Snowflake and Tule claim groups of the Grove property.
Snowflake Mining Company Ltd. examined the occurrence area in 1981. The occurrence was rediscovered by Laramide Resources Ltd. in 1983; 12 holes, totalling 996 metres, were drilled and ground magnetic and induced polarization surveys were completed. The following year, a program of geological mapping, rock sampling and ground magnetic and induced polarization surveys were completed. In 1986, Lornex Mining Corp. Ltd. completed an induced polarization survey and six diamond drillholes, totalling 576.7 metres, on the Snowflake property. In 1987 and 1988, Gerle Gold Ltd. conducted 1543 metres of diamond drilling in 18 holes. Total drilling between 1983 and 1988 amounts to 3801 metres in 41 holes.
In 2001, the Douglas Lake Cattle Co. staked the area as the Blue Jay 1-7 claims and completed a limited program of geological mapping and rock sampling the following year. 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 2008, Christopher James Gold Corp. completed a 1113.5 line-kilometre airborne magnetic-radiometric survey on the Big Kidd 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 Aspen Grove property.
In 2012, Richard Billingsley completed a photo geological structural (lineament) analysis on the area. In 2013, New Chris Minerals Ltd., on the behalf of Richard Billingsley, completed a program of rock and soil sampling on the area as the Aspen Grove property. 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.
