The Malachite Ridge (Malachite Bowl) occurrence is located on a ridge southeast of Jock Creek, approximately 6 kilometres south-southwest of the creek’s confluence 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.
Locally, two zones of mineralization, referred to as the Malachite Ridge and Malachite Bowl zones, have been identified; the Malachite Bowl zone is located immediately southeast of the Malachite Ridge zone. This mineralization is hosted in volcanics and augite porphyry of the Upper Triassic Stuhini Group, which are in contact with an Early Jurassic quartz monzonite intrusive body. The volcanics adjacent to the intrusive are fractured and in places show intense quartz stockwork. Epidote, chlorite± serpentine alteration occurs along fractures. Numerous northwest-trending feldspar porphyry and quartz monzonite dikes, ranging from 1 to 15 metres wide, are also reported.
The Malachite Ridge zone, as identified from float and subcrop samples, consists of weathered, oxidized and vuggy quartz veins containing carbonate, malachite, azurite, chalcopyrite and pyrite with occasional galena and sphalerite.
The Malachite Bowl zone, as identified from outcrops, comprises contact zones of volcanics and monzonite with quartz stockwork zones containing up to 10 per cent disseminated pyrite and 3 to 5 per cent chalcopyrite. The mineralized zones vary from 0.5 to 1.0 metre wide.
In 1980, a sample (JC-11-80-3a) of quartz vein material in feldspar porphyry from the area assayed 0.1 gram per tonne gold and 17.4 grams per tonne silver (Assessment Report 09747).
In 1999, two samples (DR-26 and DB-10) of quartz-calcite-epidote veining yielded 0.221 and 0.440 gram per tonne gold (Assessment Report 26251).
In 2003, rock samples from the area yielded up to 17.6 grams per tonne silver, 0.436 per cent copper and 0.810 per cent zinc (Assessment Report 27429).
In 2004, a float sample from the Malachite Ridge zone assayed 3.82 grams per tonne gold, greater than 200 grams per tonne silver and greater than 1 per cent copper, whereas other samples yielded up to 0.09 per cent tungsten (Assessment Report 27634). Also at this time, a sample from the Malachite Bowl zone of chlorite-altered rock with quartz veinlets and pyrite crystals assayed 1.95 grams per tonne gold, 57.9 grams per tonne silver and 0.77 per cent copper, whereas other samples from the southwest region of the zone, at the volcanic-intrusive contact, yielded up to 0.16 per cent tungsten (Assessment Report 27634).
In 2017, a rock sample (952370) assayed 0.665 gram per tonne gold (Assessment Report 37516).
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.
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 surveying and 1940.0 line-kilometres of airborne magnetic surveying on the area as the Joy property.
