The Granite Scheelite prospect is on the southwest slope of Granite Mountain, about 30 kilometres west-southwest of Princeton.
Granite Mountain is primarily underlain by hornblende, biotite and garnet-bearing amphibolites of the Late Jurassic to Early Cretaceous Eagle Plutonic Complex. These rocks are intruded by quartz-albite-muscovite pegmatite dykes. Diamond drilling in the vicinity of the deposit encountered mostly hornblende-quartz-feldspar gneiss (amphibolized metavolcanic).
A shear zone strikes 150 to 160 degrees for at least 900 metres and dips vertically to 80 degrees northeast. The zone, which averages about 1.8 metres in width, is developed along the western segmented margin of a pegmatite dyke. The shear contains a system of parallel and bifurcating quartz veins 2.5 to 100 centimetres wide. The sheared wallrock is highly silicified for up to 0.6 metre from individual quartz veins. Sericite and epidote are also noted.
The veins are comprised of slightly ribboned, occasionally vuggy quartz, containing blebs, small lenses and disseminations of pyrite, chalcopyrite, galena and sphalerite in fractures and along contacts. Grains of greenish to amber-coloured scheelite are also reported in the quartz. Disseminated pyrite and chalcopyrite are present in the silicified wallrock. Very fine-grained pyrite, chalcopyrite and galena occur throughout the rest of the zone. Grab sampling returned values of up to 60 grams per tonne and silver values of nearly 2000 grams per tonne in narrow quartz veins carrying chalcopyrite, sphalerite and galena (Geological Fieldwork 1991, page 59). A channel sample taken across the shear at the face of an adit assayed 8.85 grams per tonne gold, 85.0 grams per tonne silver, 0.28 per cent copper, 0.05 per cent lead and 0.13 per cent zinc over 1.8 metres (Property File - A.F. Roberts, 1972, assay certificate). A chip sample across 20 centimetres of quartz, with scheelite and sulphides, exposed in a trench assayed 4.1 grams per tonne gold, 58 grams per tonne silver and 0.05 per cent tungsten trioxide (Bulletin 10, page 116).
Inferred reserves of the Central zone are 72,568 tonnes grading 79.87 grams per tonne silver and 9.08 grams per tonne gold (Statement of Material Facts, February 28, 1980 - Northern Lights Resources Ltd., R.W. Phendler, October 17, 1979). The reserves are estimated over a strike length of 270 metres, with a minimum mining width of 0.91 metre projected to a depth of 90 metres. Grades quoted are diluted.
The deposit was first explored some time prior to 1942. Silver Tip Explorations Ltd. drove a 46-metre long adit along the shear zone in 1969, extracting a 120-tonne bulk sample in the process. Long Lac Mineral Exploration Ltd. drilled 5 holes totalling 307 metres in 1980.
