The Blue Jay occurrence is a copper prospect in the historical Aspen Grove copper camp, between Merritt and Princeton, where exploration dates back to the turn of the twentieth century. This prospect is located about 800 metres east of Highway 5A, 1.5 kilometres north-northwest of the northern end of Tule Lake and 5 kilometres north of the community of Aspen Grove. The Tab occurrence (092HNE052) is about 500 metres to the south.
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 Blue Jay 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 include 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 diorite to monzonite, about 500 metres wide, of Late Triassic to Early Jurassic age. 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 Blue Jay occurrence is underlain by fine-grained porphyritic basaltic and andesitic volcanics and equivalent volcaniclastics, and minor sedimentary rocks, and a composite body of fine, medium and coarse-grained diorite and porphyritic monzonite. Hybrid volcanic-intrusive characteristics in some rocks in the contact area support a comagmatic origin. Most rocks contain fracture-related and disseminated pyrite, up to 8 per cent, and magnetite. Patterns of induced polarization response correlate well with the concentration of pyrite. 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 is 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 Blue Jay occurrence is near the northern end of this zone (the Tab occurrence, 092HNE052, is near the southern end). This zone is also characterized by strong fracturing, brecciation in the diorite, and by above-average pyrite. The alteration is propylitic and carbonate, 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).
Mineralization is exposed in numerous trenches over a 300 by 200 metres area in this volcanic-intrusive contact zone, which has also been explored by percussion and diamond drilling (Bulletin 69; Preliminary Maps 10, 15; Assessment Report 9386). One prominent zone of mineralization, up to 30 metres wide, has been traced northward for 230 metres. Malachite is quite common on fracture surfaces; minor chalcopyrite, bornite, and chalcocite are diffusively disseminated in rusty weathering carbonate-pyrite zones. Native copper is present locally in fine-grained diorite and volcanics as fine disseminated specks; it and the chalcocite are probably primary and not of supergene origin (Assessment Report 7122).
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). One sample taken along the bottom of a trench assayed 0.29 per cent copper over 45 metres (Assessment Report 7122, page 3). Two percussion holes drilled in the area of the trenches analysed at least 0.1 per cent copper over 15 metres or more (Assessment Report 9386, Map SF-81-2). A diamond-drill hole, containing fine, patchy disseminated pyrite, chalcopyrite and minor bornite in sheared and propylitic-altered andesite, analysed 0.19 per cent copper and 0.204 gram per tonne gold over 97.6 metres (Assessment Report 22148, page 22, hole 91-1, 14.0 to 111.6 metres). Precious metal values are low, but anomalous, and do not necessarily correlate with high copper values. Rock sampling in 1985 yielded gold values of 0.135 to 0.595 gram per tonne and silver values of up to 1.8 grams per tonne (Assessment Report 13714, page 9). More recent sampling yielded gold values of up to 1.67 grams per tonne (Assessment Report 22148, page 18). One percussion- drill hole contained hydrocarbons of unknown origin (Assessment Report 7122).
The Blue Jay prospect has been explored by various operators, beginning with Granby Mining, Smelting and Power Company Ltd. in 1958, which completed a magnetometer survey over the occurrence. Valnica Copper Mines Ltd. drilled 6 holes totalling 600 metres in 1967. Ashland Oil and Refining Company and Rio Tinto Canadian Exploration Ltd. geologically and magnetically surveyed the deposit in 1968 and 1971. A number of percussion holes were drilled by Craigmont Mines Ltd. in 1973 and Cominco Ltd. in 1978 and 1979. Snowflake Mining Company Ltd. and Laramide Resources Ltd. completed geological and rock geochemical surveys in 1981 and 1985. Quilchena Resources Ltd. conducted geological and geophysical surveys and drilled three holes totalling 710 metres in 1991. 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 404 line-kilometre airborne geophysical survey on the area as the Aspen Grove property.