The Andreana showing is located at 2135 metres elevation, approximately 400 metres north of Joe Lake, 13 kilometres south-southwest of Keremeos, British Columbia.
Scheelite was first discovered in 1978 by R. Schneider. The claims were optioned to Dankoe Mines. A subsequent option agreement was reached with Black Giant Mines and an exploration program was conducted in 1979. The exploration program consisted of 7 diamond- drill holes totalling 592 metres, soil and stream sediment sampling, a magnetometer survey and local geological mapping. Later in 1979 the claims were restaked as the Birthday claim group by P. Folk. Drill core was relogged and analysed for tungsten, gold and silver.
The showing is hosted by Triassic Independence Formation chert and greenstone and chert, tuffs and greenstone of the underlying Carboniferous to Triassic Shoemaker Formation. In addition, a small volume of very hard siliceous tuff breccia, possibly Tertiary, and a small dike-like body of porphyritic diorite were observed. A thin sill of rhyolite porphyry has also been observed in drill core. This sequence has been intruded by the Middle Jurassic Similkameen intrusion, which lies some 2 kilometres to the south or east. Triassic strata have been folded with emplacement of the porphyritic diorite along the north trending axial plane of a poorly defined anticline. Greenschist grade, regional metamorphism has produced a pervasive foliation. Chlorite, epidote, pyrite and thin skarn bands are present on a regional scale.
Scheelite occurs in narrow bands and lenses within pyritized and silicified strata of the Shoemaker Formation. Small occurrences of scheelite-epidote skarn and scheelite-bearing quartz veinlets are widespread. The porphyritic diorite also hosts disseminated scheelite. Diamond drilling beneath the surface scheelite showing indicate that mineralized zones are lens-shaped. The Best scheelite exposures are along a ravine.
These exposures are high grade pods and lenses yielding up to 0.61 per cent tungsten over 2.4 metres, 0.5 per cent tungsten over 3 metres and close to 2 per cent tungsten in select samples (Assessment Report 8789). The best trench sample taken in 1979 by Black Giant Mines yielded 0.8 per cent WO3 over 3.5 metres (Dick, H. (1980): Diamond Drilling Report on the Joe Lake claim group). The best tungsten analytical results of relogged drill core yielded 1.42 per cent tungsten over 1.6 metres from drillhole #6 and 0.19 per cent tungsten over 4.5 metres from drillhole #5 (Assessment Report 8789).
