The area of the Canyon 18 showing is underlain by Triassic quartz diorite that has intruded Upper Triassic greenstone of the Stuhini Group.
Mineralization is reported to occur in fracture zones in megacrystic granite and in diorite. Argillic and propylitic alteration of the host rocks is common. The sulphide-quartz veins average 2 centimetres in width and are oriented parallel to the plagioclase porphyry dikes. Malachite and azurite staining covers crevices in the mineralized zones.
The main zone has been traced for 450 metres along strike and averages 25 metres in width. Within the zone the distribution of individual veins is variable; concentrations average one vein for every metre of rock. Veins are composed primarily of quartz containing veinlets and blebs of chalcopyrite and minor bornite. A few veins contain sections of massive chalcopyrite, but on average they run 5 per cent chalcopyrite. Rock samples assayed up to 3.52 grams per tonne gold and 20.8 per cent copper (Assessment Report 21479).
Work History
Previous work in the Grand Potter area was limited to mapping and rock sampling performed by Silver Standard Mmes in 1964. (Bik claims, Assessment Report 592).
In 1988 the Canyon 18, 19, 35, 36 and Gran 14 claims (South Scud property) were staked and later acquired by Homestake Mineral Development Co and Equity Silver Mines Ltd. Reconnaissance level exploration was performed by Homestake in 1989. Homestake prospected the property in 1989; reporting no significant results. 31 rock and 166 soils samples were collected. Work involved 1:10,000 scale mapping as well as the collection of 26 rock samples and 9 silt samples.
In 1990, Operator Yukon Minerals conducted reconnaissance traverses on the South Scud property located copper mineralization in a series of parallel quartz veins hosted by granite on the east side of the claim group. A 3.5 kilometre picket grid was established over the showing to facilitate mapping and soil geochemistry.