The Amethyst Cirque occurrence is located on a northeast-facing slope at an elevation of approximately 1750 metres, southeast of Jock Creek and approximately 5.8 kilometres south-southwest of the creek’s junction with the Toodoggone River.
Regionally, the area is situated within a Mesozoic volcanic arc assemblage, which lies along the eastern margin of the Intermontane Belt, a northwest-trending belt of Paleozoic to Paleogene sediments, volcanics and intrusions bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins.
Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region. They are commonly in thrust contact with Upper Triassic Stuhini Group andesite flows and pyroclastic rocks, and marine sedimentary and volcanic rocks of the Lower to Middle Jurassic Hazelton Group. These rocks have been intruded by plutons and other bodies of the mainly granodiorite to quartz monzonite Early Jurassic Black Lake Suite and are in turn unconformably overlain by or faulted against Lower Jurassic calc-alkaline volcanics of the Toodoggone Formation (Hazelton Group).
The dominant structures in the area are steeply dipping faults that define a prominent regional northwest structural fabric trending 140 to 170 degrees. In turn, high-angle, northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.
Mineralization consists of epidote-altered siliceous zones with disseminated galena and chalcedonic-amethystine quartz veins hosting chalcopyrite and pyrite, whereas up slope to the southwest, a chlorite-epidote–altered monzonite hosts galena and sphalerite.
In 2004, a chip sample (151855) assayed 0.752 per cent copper over 0.10 metres, whereas two other chip and outcrop samples (185828 and 185854), taken at locations to the southwest, yielded 0.504 and 0.944 per cent lead with 0.531 and 0.371 per cent zinc over 1.0 and 20.0 metres, respectively (Assessment Report 27634).
Another zone of mineralization, referred to as the PSQ zone, is located approximately 1 kilometre to the southwest and consists of chalcedonic and amethystine quartz vein systems on the east (down-dropped) side of the Black Lake fault in Toodoggone Formation flows and tuffs.
Work History
In 1971, Cordilleran Engineering Ltd. completed an induced polarization and resistivity survey on the area as the J.K. claim. This work identified minor occurrences of chalcopyrite, sphalerite, galena and hematite in the volcanic rocks associated with an electromagnetic conductor coinciding with a very extensive copper geochemical anomaly on the flank of a sharply positive magnetic feature.
In 1980 and 1981, Serem Ltd. completed programs of prospecting; geological mapping and rock, silt and soil sampling on the area as the Nub Mountain 1-5 claims. During 1987 through 1989, Toodoggone Gold Inc. completed programs of geological mapping, geochemical (heavy mineral, rock, silt and soil) sampling, trenching and a 248.0 line-kilometre airborne magnetic and electromagnetic survey on the area as the Fine 1-4 claims.
In 2003 and 2004, Stealth Minerals Ltd. completed programs of prospecting; geological mapping and rock, silt and soil sampling on the area as the Nub claims.
During 2016 through 2018, Amarc Resources Ltd. completed programs of soil and rock sampling, geological mapping, 115.0 line-kilometres of ground induced polarization surveying and 1940.0 line-kilometres of airborne magnetic surveying on the area as the Joy property.
