The Rupert showings (veins 1-5), 35 kilometres southwest of Atlin, occur at elevations from 1175 to 1550 metres on the west side of Taku Arm, northeast of White Moose Mountain and below the Fee Glacier.
The Rupert prospect occurs in the area of a Middle Devonian gneissic assemblage of the Yukon-Tanana terrane (Nisling?) at or near the contact of the Early Jurassic Aishihik Suite consisting of granodiorite. About 500 metres west the Devonian assemblage is in contact with the Permian gneissic assemblage of the Boundary Ranges Metamorphic Suite (Stikinia terrane). Tertiary rhyolite, andesite, and basalt dikes of the Sloko-Hyder Plutonic Suite intrude the older units. The Llewellyn fault is 10 kilometres to the northeast.
Narrow discontinuous quartz veins are hosted in pelitic schists, gneisses, and granodiorites. The veins are up to 1 metre wide in shear zones and up to 3 metres wide in the granodiorite. Sulphide content is highly variable, usually less than 1 per cent. The veins often pinch out into barren shear zones, and several are en echelon. The veins strike from 020 to 166 degrees and dip 50 to 80 degrees west. The veins consist of massive white, locally vuggy quartz with massive to disseminated galena, pyrite, sphalerite, and minor arsenopyrite and chalcopyrite. Weathered portions contain azurite, malachite, and limonite. Particles of native gold have also been reported and the best samples are believed to be from vein 4.
Intermediate to felsic dikes are spatially related to mineralized quartz veins. The veins are mesothermal to epithermal in style. Chloritized alteration haloes and iron-staining occurs adjacent to the veins from 1 to 5 metres into the wallrock. Rhyolite-dacite dikes often have argillic alteration where adjacent to or cut by quartz veins.
The lowest vein (No. 1), at about 1175 metres elevation, outcrops in a gulch, strikes about 100 degrees and is 0.6 to 0.9 metres wide. Above the No. 1 vein, at about 1265 metres elevation, is the No. 2 vein, which is 1.8 to 2.4 metres wide, strikes 107 degrees, and is nearly vertical. The No. 3 vein, at 1286 metres elevation, is 0.6 to 0.9 metres wide and parallels the No. 2 vein. The No. 4 vein, 0.1 to 0.3 metres thick, occurs at 1465 metres elevation. At 1570 metres elevation, the No. 5 vein is 1.2 metres wide. Veins 1 to 4 can be traced for several hundred feet with persistent strikes and widths. A number of old blast pits are located in the area of mineralization.
A grab sample from vein 2 assayed 4.11 grams per tonne gold, 53.83 grams per tonne silver, 11.77 per cent lead, 0.60 per cent zinc, and 0.01 per cent copper. A 0.8-metre-wide chip sample across vein 3 assayed trace gold, 237.6 grams per tonne silver, 0.26 per cent lead, 0.32 per cent zinc, and 0.01 per cent copper (Assessment Report 8384). Samples taken of white quartz veins with bands and disseminations of galena and pyrite assayed up to 0.510 grams per tonne gold (343967) and 8 grams per tonne silver (343970) (Assessment Report 19827).
The showings were probably discovered at around the turn of the century. In 1900, the property was owned by Misters Rupert and Johnson, who had apparently been prospecting and developing the showings for several years previously. Trenching, reported in 1913, located 5 mineralized quartz veins. A title to a large group of claims on White Moose Mountain was acquired by Misters Partridge and Edgerton, and prospecting and development work was carried out during 1914, however, it is not known-if the Rupert group was included in these claims. Development work, apparently done prior to 1900, consisted of 96 metres of drift and crosscut on the No. 1 vein, and a second adit of unknown length.
The Fee Group was staked to cover these showings in 1979 by United Keno Hill Mines Limited and they conducted extensive geological and geochemical surveys. In 1986, Rise Resources optioned the Ice 1 claim and the 10 crown grants comprising the Rupert Group. Rise Resources confirmed the soil anomalies discovered by United Keno Hill Mines Ltd. Placer Dome optioned the property in 1989 and conducted mapping, geochemical sampling, and geophysical surveys.
Mapping, prospecting, rock -, silt -, and soil sampling occurred at several of the Rupert showings (I, J, K, L, and approaching F) (Assessment Report 19827), and integration of this work with the latest 2007-2008 airborne geophysics has demonstrated a probable structural control on the mineralization there. The analysis suggests a strong association of mineral occurrences with north-northwest-trending magnetic lineations that clearly transect granodiorite/gneiss contacts at multiple locations.
The 2011 airborne magnetic and EM geophysical survey over the Titan property indicated a string of airborne magnetic and EM geophysical anomalies that can tentatively be traced along strike from the Buchan showing area (104M 035), as far as 2 kilometres to the south-southeast, where the geophysical anomaly lineament also overlaps with the historical Rupert I showing (104M 008).
Refer to the Titan prospect (104M 089) for related details of the Titan property, of which the Rupert showings are part of.
