The Johnny occurrence is located approximately 108 kilometres northeast of the community of Dease Lake.
The area is underlain by south-dipping carbonate of the Lower Cambrian Atan Group, which are overlain by phyllites of the Cambrian to Ordovician Kechika Group. The strata is intruded by a small Cretaceous(?) quartz-feldspar porphyry stock and associate dikes and sills. Intrusion of the stock has produced a doming of the sediments and an extensive zone of hornfels within the phyllites. Low sulphide garnet-diopside skarn and overlying cherty, light-green to brown hornfels are exposed at the dolomite-phyllite contact immediately west of the stock.
Mineralization present includes scheelite, molybdenite, pyrite, pyrrhotite, galena and sphalerite, chalcopyrite, powellite, arsenopyrite and rhodochrosite. Scheelite and powellite occur within light-green skarn, garnet skarn and magnetite skarns. Scheelite occurs as blue and yellow fluorescing, coarse crystals up to 2 centimetres long in the magnetite skarn and fine-grained to powdery disseminations in the light-green and garnet skarns. Scheelite and powellite in the skarns are concentrated in a zone 200 metres long by up to 35 metres wide.
Molybdenite occurs as disseminations and streaks within the light-green and brown cherty hornfels and flakes along narrow fractures in the hornfels. Traces of disseminated molybdenite are also present in the light-green skarn and garnet skarn.
Galena-sphalerite and pyrrhotite occur in diopside-quartz veins within dolomite and in discontinuous pods with pyrite and chalcopyrite along the phyllite-dolomite contact. Pyrrhotite is common throughout all the rock units but is most abundant within the phyllitic and cherty hornfels as disseminations, veinlets and massive pods. Chalcopyrite blebs and veinlets are commonly associated with the massive pyrrhotite pods and are locally present within the dolomite and cherty hornfels. Massive arsenopyrite was observed in float with pyrite, galena-sphalerite and quartz. Rhodochrosite occurs in vertical, black-weathering carbonate veins with minor disseminated sphalerite, chalcopyrite, arsenopyrite and galena.
Work History
In 1971, the Johnny claims were staked by C.J. Shandallahese and explored by the Caltor Syndicate in the same year. Work included grid magnetometer, EM-16 survey, prospecting and mapping on a lead-zinc-silver skarn showing located southeast of Blue Sheep Lake. The mineralization is associated with skarn development at a limestone-felsic intrusive contact. The highest grade lead mineralization of five samples from the showing assayed 454 grams per tonne silver, 7.5 per cent lead, 1.23 per cent copper and 0.26 per cent zinc. The highest zinc mineralization assayed 4.32 per cent zinc, accompanied by 5.85 per cent lead, 93 grams per tonne silver and 0.14 per cent copper (Assessment Report 24764). No further work was carried out and the claims were allowed to lapse.
In 1980 and 1981, Amax of Canada Limited staked five Sky claims totalling 67 units. An exploration program of soil, silt and rock geochemical sampling and mapping was carried out in 1981, focussing on scheelite and molybdenite-bearing skarns located southeast of Blue Sheep Lake. The program outlined a 200- by 35-metre scheelite, molybdenite and powellite mineralized skarn zone developed in Atan Group carbonates intruded by a Cretaceous(?) quartz-feldspar porphyry stock. An average grade of 0.5 per cent tungsten tri-oxide plus molybdenum disulphide over 5 metres width was estimated for the skarn zone. Amax also soil sampled the breccia zone north of Blue Sheep Lake where galena, sphalerite and pyrite mineralization was found in intensely altered ‘dolostone’ fragments within the breccia. Highly anomalous lead, zinc and silver analyses were obtained in soils. It is this area that attracted Atna Resources Ltd. and resulted in the staking of the Bx 1 claim in 1995. In 1996, Atna Resources Ltd. explored the northeast comer of the Blue Sheep property (Bx 1 claim) by grid soil sampling, prospecting and mapping. Grid soil samples (83) were taken at a line spacing of 100 metres and sample interval of 25 metres and 13 rock samples were taken for whole rock geochemical analysis.
In 2005, an airborne magnetic and electromagnetic survey totalling 2,130 line-kilometres was flown over the Thrust property on behalf of United Exploration Management Inc.
In 2012, BCarlin Resources Ltd. completed a program of rock and silt sampling on the area as the B 1-100 claims of the Blue Sheep property.
