The Bluebell occurrence consists of gold mineralization, located 3.25 kilometres northeast of Perkins Peak, 20 kilometres southwest of the community of Kleena Kleene. The geological setting is essentially the same as for the Mountain Boss deposit (092N 010) which lies 1.2 kilometres to the west, and which is notable for high values of gold and silver with sulphides in quartz veins and zones of silicification.
The Bluebell Prospect is hosted by Lower Cretaceous rocks of the Cloud Drifter Formation consisting of arkosic and quartz sandstone, siltstone and minor dark grey to black shale, with minor discontinuous conglomerate lenses. The formation is generally tightly folded, with fold vergence to the north although in the Miner Lake valley, immediately north of the area, the structure is a broader anticline. Along the steep north-facing slope of the Colwell Lake-Miner Lake valley, in the vicinity of the Mountain Boss and Bluebell prospects, Bouma sequence deposition is exposed along road cuts and indicates deep water conditions, possibly as turbidites. The Bluebel is located about 11 kilometres southwest of the Tchaikazan fault, and approximately 5 kilometres northeast and southeast of the margin of the Jurassic to Paleogene Coast Plutonic Complex (Geological Survey of Canada Open File 1163, Map 1713A).
Rocks in the area consist of silicified black carbonaceous argillite, dark brown argillaceous sandstone or greywacke, and cherty conglomerate. The beds are gently folded but generally strike between 060 and 070 degrees, and dip southeast between 30 and 60 degrees. Faulting is generally minor, although locally there is strong fracturing. Andesitic flows and breccias conformably overlie the sedimentary rocks, and outcrop 1.5 kilometres to the south near Perkins Peak and southwards.
The silicification in the area, which includes several gossans, has been attributed to a small quartz diorite stock which occurs about 1 kilometre south of the Bluebell occurrence, and which is probably a satellite intrusion of the Coast Plutonic Complex. Numerous small, altered felsic to intermediate dykes and sills which intrude the sedimentary rocks may be related to the stock. Sulphide mineralization is proportional to the degree of silicification in the sedimentary rocks and quartz dioritic intrusions.
The occurrence is centred on the Bluebell adit. A significant Very Low Frequency (VLF) electromagnetic conductor around the adit is in alignment with that around the Mountain Boss occurrence, and it is likely that they represent portions of the same zone of mineralization (Assessment Report 6397; Minister of Mines Annual Report 1945). Around the adit are several irregular and poorly defined silicified zones, 3 to 6 metres wide, with minor disseminated arsenopyrite, containing a small amount of gold ("East" showings in Geological Survey of Canada Summary Report 1925). Several lenses and stringers of quartz, and massive pyrite and arsenopyrite are present at the Bluebell adit along the sheared contact between silicified argillite and black graphitic argillite. The latter represents a "substantial occurrence of graphite" which may have been produced by a leaching process related to the shear zone (Minister of Mines Annual Report 1945). The rocks are strongly oxidized, even below the surface.
See Mountain Boss (092N 010) and Briton (092N 011) for related geological and work history information.
