The Mystery occurrence is located at an elevation of approximately 1680 metres on a southeast-facing slope, west of Alki Creek and approximately 1.6 kilometres southeast of Mount Murphy.
Regionally, the area is underlain by rock of the Mesoproterozoic Aldridge Formation (Purcell Supergroup). These are fine-grained clastics that include impure quartzites, siltstones and argillites. The sedimentary rocks have been metamorphosed to lower green schist facies and have been intruded by a series of mafic sills and dikes.
Locally, a series of adits, driven in a gabbro sill, are reported to expose quartz veins hosting chalcopyrite with minor sphalerite and galena mineralization. Arsenopyrite, pyrrhotite and pyrite are also reported to be common. Bornite and native copper have also been reported. The adits are situated in a relatively wide east-trending pyritic zone.
In 1920, a grab sample from a dump estimated to contain approximately 227 tonnes assayed 6.8 per cent copper (Annual Report 1920-119).
In 1924, sampling of two veins, referred to as the east and west veins, is reported to have yielded 1.6 and 6.0 per cent copper, 30.9 and 37.7 grams per tonne silver with 2.06 and 1.03 grams per tonne gold, respectively (Property File - Starr, Charles C. (1924-09-01): Abstract of Report of C.C. Starr - Pollen - Dewar - Meacham Groups).
In 2011, a sample (GL-761S) of muck from the upper adit assayed 3.91 grams per tonne gold and 8.3 grams per tonne silver, and a grab sample (GL-730) of float from the lower adit yielded 1.47 grams per tonne gold, 4.3 grams per tonne silver and 0.56 per cent copper (Assessment Report 32814). Also at this time, an undescribed sample (0179782) from the Mystery occurrence area yielded 2.88 grams per tonne gold (Assessment Report 33145).
Another quartz vein hosting minor sulphides is reported approximately 900 metres to the south-southeast on the Magnet (L. 7213) Crown grant. The vein strikes north and dips 60 degrees east. The vein has been traced for approximately 305 metres along strike with varying widths of approximately 0.3 to 10.7 metres.
Work History
Three historical adits, likely dating to the late 1890s or early 1900s, have been reported in the occurrence area. Other sources indicate the adits to be located approximately 200 metres to the south-southwest of the adit locations identified in 2011. By 1920, a tunnel is reported to have been driven for approximately 55 metres. In 1924, development work is reported to have included three tunnels, totalling approximately 72 metres, and an 8-metre winze.
In 1956, Green Bay Mining an Exploration Ltd. is reported to have completed a geophysical survey and approximately 914.5 metres of exploration drilling on the Mystery claim.
In 1971, Kerr Addison Mines Ltd. conducted a regional program of geological mapping and geochemical (soil and silt) sampling on the are as part of the Dewar Creek project. In 1979, Cominco Ltd. conducted a geological mapping program on the area as the Clair 6-10 claims. In 1983, Noranda Mining and Exploration Inc. conducted an airborne magnetic and electromagnetic survey on the area as part of the Mount Evans property.
In 1992, Cominco completed a 14.0 line-kilometre ground electromagnetic survey on the area. During 1996 through 1999, Abitibi Mining completed exploration programs of prospecting, geological mapping, geochemical (rock, soil and silt) sampling and a gravity survey on the area as the Clair, Cleo and PMR claims. In 1999 and 2000, Rio Algom Exploration completed exploration programs consisting of geological mapping, rock sampling and three diamond drill holes, totalling 2555.2 metres, on the area as the Pyramid Peak property.
During 2011 through 2013, Electra Gold completed programs of rock sampling, geological mapping and prospecting and a photo-geological interpretation program on the area as the Gold Ledge property.
