The Silver Cirque (Mac) occurrence is located on the western flank of Mount McNamara, approximately 3.5 kilometres south of the Chukachida River and 263 kilometres northwest of the community of Germansen Landing.
The area is underlain by marine sedimentary rocks and volcanic rocks of the Upper Triassic Stuhini Group. These have been intruded by the Early Jurassic Black Lake intrusive suite consisting of generally medium-grained granodiorite to quartz monzonite.
Locally, a 500 by 500 metre subcropping exposure of ‘toasted’ and phyllic altered andesite flows as well as a large percentage of rhyolite occurs. Alteration includes sericite, barite and occasionally fluorite. Mineralization comprises disseminations of sphalerite, galena, chalcopyrite and minor tetrahedrite.
The Silver Cirque area consists of red hematitic beds of fine grained to conglomeratic material, along with light green cherty units found stratigraphically above the red beds. These were previously mapped as an epiclastic unit. To the east of the ‘red beds’ on the floor of the cirque, altered andesite tuffs are rarely exposed and were previously assigned to the Metsantan Member of the Toodoggone Formation. The tuffs are elevated in barium and mercury, with several samples anomalous in silver.
In 2004, float samples (185354 through 185375) of propylitic-altered andesite hosting quartz-barite stockwork veins with disseminated pyrite, chalcopyrite, galena and malachite from the occurrence area yielded values of up to 26.96 grams per tonne gold, 1170 grams per tonne silver, 0.329 per cent copper, 0.309 per cent zinc and greater than 1.00 per cent lead (Assessment Report 27633).
In 2005, a subcrop chip sample (64613) of chlorite-altered, weakly sheared rock peripheral to a monzonite stock assayed 29.60 grams per tonne gold and 4.7 grams per tonne silver, whereas possible extensions of the mineralized zone in outcrop from cliffs to the southeast yielded 0.440 gram per tonne gold over 0.6 metre (sample 64616; Assessment Report 28041). Also at this time, two float samples (64610 and 64237) from the occurrence area and to the southeast yielded 1110.0 and 1350.0 grams per tonne silver, respectively, with up to 0.390 grams per tonne gold, 0.288 per cent copper, 0.116 per cent lead and 0.115 per cent cadmium (Assessment Report 28041).
In 2006, float samples (G06228) from the main Silver Cirque zone yielded up to 52.6 grams per tonne silver, 0.565 per cent lead and 0.371 per cent zinc, whereas two subcrop samples (G06218 and G06219) of barite-quartz veinlets with hematite, galena, sphalerite and chalcopyrite, located approximately 600 metres to the north-northeast, yielded 0.367 and 0.315 per cent lead, 0.432 and 0.384 per cent zinc with 611 and 451 grams per tonne silver, respectively (Assessment Report 28646).
In 2018, a grab sample (4111) from an outcrop of brecciated siliceous tuff(?) hosting disseminated specularite(?) and galena(?), from the north-northeast area previous sampled in 2006, assayed 63.8 grams per tonne silver, 0.530 per cent lead and 0.125 per cent zinc, whereas a nearby float sample (4062) of potassium feldspar-altered volcanic with minor malachite staining and amethyst stockwork assayed 419 grams per tonne silver (Assessment Report 38272). Also at this time a grab sample (4015) from an outcrop of chlorite-epidote–altered basalt in contact with a granodiorite dike with malachite staining, located approximately 750 metres to the southeast, yielded 0.669 per cent copper, whereas a nearby float sample (4014) of malachite-stained granodiorite assayed 1.045 per cent copper (Assessment Report 38272).
Work History
In 1981 and 1982, Golden Rule Resources Ltd. completed programs of geological mapping and geochemical (rock, silt and soil) sampling on the area as the QBX 1-12 claims.
In 1984, Newmont Exploration of Canada Ltd. completed a program geological mapping, geochemical (rock, silt and soil) sampling and ground magnetic and electromagnetic surveys on the area as the Lynx 1-7 and Guard claims. This work identified a zone (Spring) of siliceous sinter containing beds of nodular agate and opal along with amethystine quartz and quartz over an area of approximately 800 by 100 metres a short distance west of the Silver Cirque occurrence.
In 1986, Toodoggone Gold Inc. completed a 278 line-kilometre airborne electromagnetic and magnetic survey on the area as the Fisher 1-2 and Wolverine 1-2 claims.
From 2004 to 2006, Stealth Minerals Limited completed exploration programs of soil and rock geochemical sampling, prospecting and geological mapping as a part of its Toodoggone project.
In 2017, Sable Resources Ltd. completed a helicopter-borne geophysical survey over the Bot property which included radiometric, magnetic, and ZTEM data. In 2018, Talisker Resources Ltd. conducted prospecting of geophysical anomalies (identified in the 2017 survey) located on the northern half of the Bot property, some coincident with historically reported mineralization of which the Silver Cirque is included. A total of 148 rock, silt and talus samples were collected and submitted for assay.
