The historic Johannesburg camp is located south of Mineral Hill and approximately 2.6 kilometres east of Stumplake Creek.
The area is within a north trending belt of Upper Triassic intermediate volcanics, volcaniclastics and sediments belonging to the Nicola Group. These greenstones consist of massive, chlorite-epidote altered andesite and basalt, augite porphyry, andesitic flow breccia and tuff, minor interbedded argillite, conglomerate and limestone. Attitudes of tuff horizons and sedimentary bedding suggest that a north plunging axis of a syncline passes through Mineral Hill. Both west and northeast of Stump Lake, the Nicola Group volcanics are intruded by Lower Jurassic granitic batholiths; scattered granodiorite outcrops have been mapped in the vicinity of the Johannesburg camp. Secondary to the north-northeast trending Quilchena and Stump Lake regional faults are numerous smaller faults which form a complex fracture pattern and appear to control alteration and mineralization. Andesitic rocks are bleached, pervasively silicified, pyritic and brecciated. Mineralization occurs in numerous quartz, and less commonly calcite veins which strike generally to the north and dip steeply eastward.
Locally, at the Azela shaft, quartz and carbonate knots and stringers strike 015 degrees and dip 55 degrees east. They are up to 35 centimetres in width and occur within a 1 to 2 metre wide shear zone. Mineralization in the veins includes pyrite, galena, sphalerite, tetrahedrite, grains and narrow bands of scheelite, minor chalcopyrite, bornite, arsenopyrite, pyrrhotite and native gold. The wallrock is altered porphyritic andesite which contains 2 to 4 per cent disseminated pyrite.
A diamond-drill hole intersection across a 1.5 metre quartz vein assayed 1.39 per cent copper, 268.0 grams per tonne silver and 2.4 grams per tonne gold (Assessment Report 8310).
In 1974 and 1975, Juniper Mines explored the area as the Stump Lake property. In 1980, two diamond drill holes, totalling 98.7 metres, were completed. In 1984, Celebrity Energy completed a program of soil sampling and ground geophysical surveys on the area. In 1985, Times Square Energy Resources completed a program of geological mapping, soil sampling and a ground electromagnetic survey on the area as the CIG 100 property. In 1987, New Hombre Resources Ltd. completed a soil geochemical survey, a VLF-EM survey, a magnetometer survey, a geological survey, and the digging of three test pits. From 1992 to 1995, the GIG 100 ground was originally covered in part by the Spud claim group and subsequently by the WJA claim group, which was owned by Module Resources Incorporated. The only work completed for Module prior to the expiration of the WJA claims, in 1995, was minor trenching. In 1995, the S claim group was staked and followed by the completion of localized exploration programs. During 1997 through 2006, Capella Resources Ltd. completed various programs of trenching, geochemical sampling and geophysical surveys on the S claim group.
