The Nub Tarn (Nub West) occurrence is located at an elevation of approximately 1600 metres in the southeast headwaters of a northwest-trending tributary of Jock Creek, approximately 7.5 kilometres south-southwest of the creek’s junction with the Finlay 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.
The area is underlain by undivided Lower to Middle Jurassic Hazelton Group volcanic rocks cut by feldspar porphyry dikes. Strong regional structures trend north-northwest and are accompanied by propylitic and argillic to advanced argillic alteration. A zone of argillic to advanced argillic alteration is largely exposed for approximately 1 kilometre in width and 5 to 6 kilometres in length between the Nub West quartz-alunite zone and the NWB (MINFILE 094E 241) to the south.
Locally, outcropping zones of northwest-trending quartz and quartz-carbonate veins between 0.5 and 1.5 metres in width are locally associated with gold and silver values within north to northwest zones of propylitic- to sericite-carbonate–altered intermediate to basaltic volcanic rocks. The quartz and quartz-carbonate veins, stockwork and breccia zones contain pyrite, chalcopyrite, sphalerite and galena associated with alunite, dickite, pyrophyllite and, locally, illite, montmorillonite and chlorite alteration assemblages.
Similar mineralization has been identified approximately 600 metres to the southeast and 350 metres to the southwest.
In 1999, a float sample (DR-48) of sphalerite in a quartz-feldspar vein assayed 2.0 grams per tonne silver and 23.5 per cent zinc (Assessment Report 26251).
In 2003, rock samples from the area yielded up to 0.28 gram per tonne gold, 26.9 grams per tonne silver, 0.720 per cent copper, 1.00 per cent lead and 6.251 per cent zinc (Assessment Report 27429).
Work History
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.
During 1999 through 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 surveys and 1940.0 line-kilometres of airborne magnetic surveys on the area as the Joy property.
