The Tab occurrence covers a small group of showings of copper 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. The occurrence is centred on a zone of mineralization called Zone 1 in Assessment Report 9386 and located 1 kilometre east of Highway 5, approximately 4 kilometres north of the community of Aspen Grove and 700 metres northwest of the northern end of Tule Lake.
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).
The Tab occurrence is one of many occurrences 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 argillite and limestone. Locally the strata strike north to northwest and dip southwest. The volcanics are intruded by a north-trending body of comagmatic Upper Triassic to Lower Jurassic diorite to monzonite, approximately 500 metres wide. 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 around the Tab occurrence is underlain by fine-grained porphyritic basaltic and andesitic volcanics and equivalent volcaniclastics, minor sedimentary rocks and a composite body of fine-, medium- and coarse-grained diorite and porphyritic monzonite. Hybrid or gradational volcanic-intrusive characteristics in some rocks in the contact area support a comagmatic origin. Most rocks contain fracture-related and disseminated pyrite and magnetite. Patterns of induced polarization and ground magnetic response correlate well with the concentration of pyrite (Assessment Reports 7122, 6260). The best copper mineralization occurs in rocks with little or no pyrite, that is, on the flanks of the induced polarization conductors (Assessment Report 7122).
Hydrothermal alteration and mineralization are strongest in a zone measuring at least 1100 by 120 metres that straddles the volcanics to the west and the fine-grained margin of the dioritic intrusion to the east (Assessment Reports 6260, 7122). The Tab occurrence is near the southern end of this zone (the Blue Jay occurrence, MINFILE 092HNE105, is near the northern end). This zone is also characterized by strong fracturing, brecciation in the diorite and above-average pyrite. The alteration is propylitic and carbonatitic, there being widespread epidote (especially along fractures), calcite, chlorite, albite, quartz, biotite, hematite and secondary potassium feldspar, although some of these minerals may represent metamorphic recrystallization (Assessment Report 7122).
At the main Tab occurrence mineralization is exposed over a north–south distance of 300 metres in numerous trenches in this volcanic-intrusive contact zone, which has also been explored by percussion and diamond drilling (Assessment Report 9386). Mineralization comprises fine patchy disseminated chalcopyrite, pyrite and minor malachite occur in altered and fractured porphyritic diorite/gabbro, which is gradational westwards with andesitic and basaltic volcanics and siltstones (Preliminary Maps 10, 15; Bulletin 69; Assessment Reports 3555, 5875, 6260, 13714, 22148). Biotite alteration is pervasive here (Assessment Report 3555). Copper values are low grade and erratic, and are generally proportional to the degree of alteration and fracturing, although the primary control appears to be the contact zone of the dioritic intrusion (Assessment Report 9386). Silver geochemical anomalies correlate more with magnetic and induced polarization highs, which reflect pyrite content, than with copper anomalies, which is consistent with the inverse relationship between pyrite and copper mineralization (Assessment Report 6260).
In 1973, drilling on the main occurrence yielded 0.115 per cent copper over 24.4 metres (51.8 to 76.2 metres down-hole) in hole BJP-1, whereas a drillhole (BJP-7) located a short distance north yielded 0.26 per cent copper over 18.3 metres (79.2 to 97.5 metres down hole; Assessment Report 7122, Plate 2).
In 1978, sampling of a trench located on the main Tab occurrence yielded 1.6 per cent over 3 metres, whereas other trenches are reported to have yielded 0.63 and 1.35 per cent copper (Assessment Report 7122).
In 1991, a chip sample from the main trenched area assayed 0.17 gram per tonne gold and 1.6 per cent copper over 2.0 metres (Assessment Report 22148, page 18).
Additional copper mineralization is found in an area extending up to 1000 metres west-southwest of the main showing. One showing exposed in numerous trenches, located approximate 500 metres southwest of the main zone, consists of epidote- and calcite-veined purple andesitic breccia with minor native copper, chalcocite and malachite mineralization over a width of approximately 3 to 6 metres.
In 1978, sampling of a trench, located on this zone, is reported to have yielded 0.9 per cent copper over 6.0 metres (Assessment Report 7122). In 1984, a rock sample assayed 3.9 grams per tonne silver (Assessment Report 13714).
A third showing lies approximately 500 metres farther southwest of the previous trenches. Here, a 9-metre-long quarry and a 4.5-metre-long adit have been driven to the southwest exposing bornite, chalcopyrite, native copper, chalcocite and malachite in green volcanic and laharic breccia. Nearby, to the east of the adit, a 2.4 (caved) shaft has been developed on a north-trending shear zone hosting minor malachite.
A fourth zone of mineralization is exposed in a 4.5-metre tunnel, located approximately 650 metres south of the main Tab occurrence, which was driven to the northeast along a dike(?) or two parallel faults in massive flow hosting minor malachite along fractures.
Another zone of mineralization is located approximately 400 metres east of the main Tab occurrence and comprises several pits exposing a fine-grained diorite hosting joint and fracture-filling disseminated chalcocite and bornite with minor malachite staining.
Work History
Historical shafts, adits and numerous trenches, likely dating to the early 1900s, are reported to have been developed on the occurrences. More recently, the Tab prospect has been explored by various operators, beginning with Granby Mining, Smelting and Power Company Ltd. in 1958, who completed a 70.8 line-kilometre ground magnetometer survey over the occurrence area as the K.M. group of claims.
Ashland Oil and Refining Company and Rio Tinto Canadian Exploration Ltd. geologically and magnetically surveyed the occurrence area in 1968 and 1971. Also, Norranco Mining and Refining drilled one hole in 1969 and conducted additional magnetometer surveying in 1971 on the area as the Tab claims. In 1973, Craigmont Mines Ltd. completed at least five percussion drill holes, totalling 375.0 metres, on the area. In 1975 and 1976, Robert York-Hardy and Fred Gingell completed programs of geological mapping, soil sampling and a ground electromagnetic survey on the area as the Snowflake claims. Cominco Ltd. drilled a number of percussion holes in 1978 and 1979, totalling at least 1280.2 metres in 14 holes. Also 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 and Laramide Resources Ltd. completed programs of geological mapping, rock sampling and ground magnetic and induced polarization surveys in 1981 and 1985. In 1986, Lornex Mining Corp. Ltd. completed an induced polarization survey and six diamond drillholes, totalling 576.7 metres, on the Snowflake property.
In 1991, Quilchena Resources Ltd. completed a program of geological mapping, rock sampling, a 4.5 line-kilometre induced polarization survey and three diamond drill holes, totalling 710.2 metres, on the Snowflake property. Also at this time, Northair Mines Ltd. completed a program of rock and soil sampling on the area as part of the Shear property.
In 2001, the Douglas Lake Cattle Co. staked the area as the Blue Jay 1-7 claims and the following year completed a limited program of geological mapping and rock sampling. 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.
