The Gold Ledge (Gold Key) occurrence is located at an elevation of approximately 2365 metres on a high ridge separating the northwestern headwaters of Alki Creek and the southwestern headwaters of Matthew Creek, approximately 700 metres northeast of Pyramid Mountain.
The area lies within the Purcell Anticlinorium. The Mesoproterozoic Purcell Supergroup is exposed in the core of the anticlinorium with the Lower Aldridge Formation forming the basal part of the Purcell Supergroup. The Lower Aldridge Formation composed of thin-bedded, rusty, quartzitic wacke and siltstone. The formation is conformably overlain by the Middle Aldridge Formation, composed of thin- to medium-bedded, rusty to grey-weathering quartz wacke, quartzitic wacke and siltstone units.
Locally, the underground workings expose a 2.4-metre wide zone of quartz-filled breccia and 7.6 metres of fractured quartz with chalcopyrite, pyrite and arsenopyrite mineralization. These are hosted by quartzite and siltstone.
In 2011, a 0.5-metre chip sample (GL-718) from schisty sediments hosting a sericite-quartz vein with galena, scorodite and arsenopyrite, located adjacent to the adit, assayed 4.97 per cent lead and 52.8 grams per tonne silver; gold values up to 34 grams per tonne are reported at the main Gold Ledge workings from previous selected sampling (Assessment Report 32814).
Approximately 650 to 1100 metres east-southeast of the Gold Ledge workings, a series of short, underground adits and shafts, refered to as the Lake zone, are reported. The Lake zone comprises structurally controlled quartz veins that display numerous subparallel narrow (0.5 to 1.0 metres wide) veins across several metres with associated anastomosing quartz veinlets hosting sulphide mineralization. The brecciated hostrock, which is composed of quartzite and siltstone, is partly replaced by sulphide mineralization adjacent to the quartz veins
In 2000, a select dump sample (16732) from the shaft, located approximately 450 metres southeast of the Lake adit, assayed 0.19 gram per tonne gold, 77.5 grams per tonne silver, 0.495 per cent lead, 0.117 per cent zinc and 3.17 per cent copper, and a sample (PLG18) taken from a historical trench, located near the Lake adit, assayed 0.48 per cent copper, 1.58 per cent lead, 4.08 per cent zinc and 39.2 grams per tonne silver (Assessment Report 26361).
In 2011, four chip samples (GL-711-2 through -5) of mineralized quartz from the front of the Lake adit yielded values from 1.97 to 5.42 per cent lead, 6.50 to 9.61 per cent zinc, 0.44 to 1.18 per cent copper, 47.7 to 99.5 grams per tonne silver and 0.02 to 0.36 gram per tonne gold (Assessment Report 32814).
Another area of mineralization is reported approximately 1300 metres to the east-northeast of the Gold Ledge workings, at an elevation of approximately 2270 metres on a northeast-facing valley, south of Matthew Creek. At this site, altered (sericitic) sedimentary rocks host quartz veins with galena. In 1997, a panel sample (136636) assayed 0.14 per cent zinc, greater than 1.00 per cent lead and 103.0 grams per tonne silver (Assessment Report 25326).
Two historical trenches are located at elevations of approximately 2150 and 2220 metres on a southeast-trending ridge in the eastern headwaters of Pyramid Creek, approximately 2 kilometres northwest of Pyramid Mountain. In 2000, samples from the upper and lower trench yielded 5.56 and 0.50 per cent lead, 0.11 and 0.01 per cent zinc, 50.2 and 16.4 grams per tonne silver with 3.26 and 6.27 per cent arsenic, respectively (Assessment Report 26361).
Another adit is reported at an elevation of approximately 2000 metres on a northwest-facing slope in the southeastern headwaters of Pyramid Creek, approximately 1.7 kilometres southwest of Pyramid Peak. The adit exposes a quartz vein with arsenopyrite and galena mineralization. In 2000, a select dump sample (16738) assayed 5.6 grams per tonne silver and 0.274 per cent lead (Assessment Report 26361).
Work History
Several small-scale workings including an adit, a shaft and numerous trenches, mainly in quartz veins and shears, in the Pyramid Mountain peak area date to the 1890s or early 1900s. Underground workings on the Gold Ledge zone are reported to consist of a 41-metre drift with a 14-metre wide crosscut. Approximately 650 to 1100 metres east-southeast of the Gold Ledge workings, a series of short, underground adits and shafts, referred to as the Lake zone, are reported. Another adit and separate zone of trenching are reported in the headwaters of Pyramid Creek on the western slopes of Pyramid Mountain.
In 1971, Kerr Addison Mines Ltd. conducted a regional program of geological mapping and geochemical (soil and silt) sampling on the area as part of the Dewar Creek project. In 1979, Cominco completed a program of soil sampling and geological mapping on the area as the Clair claims 6-10. In 1982 and 1983, Cominco completed a ground electromagnetic survey and a seismic survey on the area.
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. In 2001, Abitibi Mining completed a program of geological mapping on the area.
During 2011 through 2013, Electra Gold completed programs of rock sampling, geological mapping and prospecting and a photogeological interpretation program on the area as the Gold Ledge property. In 2019, Wild West Gold Corp. conducted a program of historical airborne geophysics and regional geochemical interpretation on the Gold Ledge property.
