The Banshee occurrence is located 25 kilometres northwest of Mount Albert Dease, north and west of Park Creek, about 148 kilometres southeast of the community of Dease Lake.
The showing is underlain by a mixed metavolcanic-metasedimentary assemblage. Early regional mapping correlated these rocks with the Asitka Group based on lithological similarities (Geological Survey of Canada Open File 483). A tentative age of Devonian to Permian is assigned to these rocks (Geological Survey of Canada Paper 76-1A, pages 87-90). Fossil evidence suggests a Mississippian age for at least part of this sequence (Geological Survey of Canada Paper 80-1B, pages 207-211). Upper Triassic Takla Group rocks lie to the northwest of the showing (Assessment Report 9615). To the southwest lie Late Triassic granitoids of the Stikine Terrane and the Early to Middle Jurassic Three Sisters granitoid suite. To the southeast and northeast, are Late Triassic to Early Jurassic granitoid rocks in the Stikine and Quesnel terranes west and east of the Kutcho fault (Open File 1990-12).
On a property scale, rocks surrounding the Banshee showing have been divided into four units. The first of these units is a mixed metavolcanic-metasedimentary unit consisting of alternating intermediate pyroclastics and argillites. These intermediate pyroclastic rocks, dacitic to andesitic in composition, are composed of quartz, sericite, chlorite, actinolite, limonite and minor calcite. Metarhyolite overlies the previous unit. It is composed of 70 per cent quartz, 28 per cent sericite and 2 per cent combined iron oxides and pyrite. Locally, this unit contains up to 3 per cent disseminated pyrite and minor galena. At the Banshee showing, this unit hosts pyrite, sphalerite, chalcopyrite and minor galena. The most widespread of the four units is a metavolcanic unit consisting of mafic volcanic rock with felsic tuff layers. Composition ranges from andesitic to basaltic. These three units are overlain by a cherty metarhyolite tuffite unit. Quartz, feldspar, actinolite, calcite and iron oxides comprise this unit. A weak to strong foliation is pervasive in all units except the cherty metarhyolite tuffite.
The rocks underlying the Banshee showing have undergone two phases of deformation and have been metamorphosed to greenschist facies. The first phase of deformation was penetrative and produced a pervasive foliation. The second, weaker phase of deformation produced local kink bands and weakly defined foliation. A major fault striking north-northwest is found immediately east of the Banshee showing.
Mineralization consists of patchy areas in metarhyolite and quartz veins, of up to 5 per cent pyrite, 1 per cent sphalerite, 1 per cent galena and 0.5 per cent chalcopyrite (Assessment Report 6915). Three trenches were dug in response to rock samples yielding assay values of 10.3 grams per tonne silver, 0.19 gram per tonne gold, 1.79 per cent zinc, 0.12 per cent copper and 0.06 per cent lead (Assessment Report 9615). Analytical results from trenches were lower than rock samples. In 1981, the best results were from Trench C, which were 9.4 grams per tonne silver, 0.16 gram per tonne gold, 0.055 per cent zinc, 0.017 per cent copper and 0.012 per cent lead (Assessment Report 9615).
In 1977, Cominco Ltd. conducted geophysical work consisting of 12 lines of induced polarization which ran from one side of the cirque floor to the other. The same grid (7.7 kilometres) was covered by ground magnetics and partially by VLF-EM.
In 1981, work by Cominco Ltd. consisted of silt (19 samples), soil (145 samples) and rock (108 samples) geochemistry and geological mapping. A surveyed grid was laid out which was sampled and mapped in detail.
