The JD West (Ag-carbonate, Schmitt and Central B zones) occurrences are located at an elevation of approximately 1820 metres on a south-facing slope, approximately 4.6 kilometres north-northeast of Kadah Lake.
Regionally, the area is situated within a Mesozoic volcanic arc assemblage that lies along the eastern margin of the Intermontane Belt, a northwest-trending belt of Paleozoic to Neogene 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 Takla Group andesite flows and pyroclastic rocks. These Takla 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 occurrence area is underlain by a thick succession of Lower Jurassic volcanics assigned to the McClair and Metsantan members of the Toodoggone Formation, separated by a low angle thrust (?) fault. The Metsantan member consists of latite flows with lenses of lapilli tuff, and lahar; minor volcanic sandstone and conglomerate (Bulletin 86). The McClair member consists of heterogeneous, lapilli to block tuff, andesitic flows and numerous cogenetic dikes and subvolcanic plugs; minor mudstone and conglomerate (Bulletin 86). Both members are dominated by flows and flow breccias around the Woof showing (Assessment Report 18015). This sequence is cut by a series of steeply dipping diabasic and rhyolitic dikes.
Alteration is structurally controlled and ranges from weak propylitic to intense silicic, argillic and sericitic. Propylitic alteration is the most widespread and important alteration type of the prospect, either hosting mineralized veins or forming haloes around more intensely altered and mineralized systems. Propylitic alteration consists of replacement of plagioclase phenocrysts by epidote or hematite and mafic phenocrysts by chlorite, epidote, actinolite, talc and disseminated calcite.
Locally, three zones of mineralization have been identified in the JD West area and are referred to as the Ag-carbonate, Schmitt and Central B zones. Mineralization at the JD West zone is characterized by quartz-carbonate breccias and veins, and clay gouge associated with a low-angle thrust (?) fault. Most of the zone contains low to medium-grade gold and silver mineralization over widths of 0.5 to 4.0 metres and a strike length of a least 600 metres (Assessment Report 18015).
The Ag-carbonate zone is interpreted to be a multiphase quartz-carbonate-acanthite vein system associated with a north-trending fault system in the McClair member of the Toodoggone Formation. Mineralization appears to consist of a lens of carbonate breccia with acanthite and sulphides. The approximate surface dimensions of the breccia lens are 2 by 3 metres. Trenching on this zone identified a complex system of structurally controlled silicification, propylization and phyllic alteration hosting a 3- to 5-metre wide quartz breccia–veined zone with variable amounts of hematite, pyrite, sericite and local chalcopyrite and galena. The zone is associated with a 1- to 3- metre wide clay gouge zone.
The Schmitt zone is located approximately 200 metres northwest of the Ag-carbonate zone and consists of a float boulder train of very high grade gold- and silver-bearing sulphide breccia. In 1981, seven surface trenches on the zone were dug to uncover the source of the high-grade float, with only one of the seven trenches intersected in-situ vein material. Trenching on this vein uncovered 6 metres of vein length including the footwall and hangingwall rocks. The vein strikes east and schistosity of the hangingwall fault gouge suggests a steep northward dip. The vein is a complex breccia with two carbonate phases hosting acanthite, galena, pyrite and trace sphalerite and chalcopyrite. The earlier carbonate phase hosts up to 60 per cent of the mineralization.
The Central B zone is located approximately 250 metres east of the Ag-carbonate zone and comprises a variably altered andesite porphyry and andesitic volcanics with hematitic quartz veins that may represent a fault-displaced, eastern extension of the Ag-carbonate zone.
In 1971, a rock sample (RGR-116) from the occurrence area assayed 58 grams per tonne silver and 2.690 grams per tonne gold (Assessment Report 3831). It is not known which of the mineralized zones this sample came from.
In 1981, samples (18736 through 18740) of high-grade float boulders from the Schmitt zone yielded values from 40.80 to 326.06 grams per tonne gold, 1297.4 to 6150.9 grams per tonne silver with up to 0.39 per cent copper, 1.27 per cent lead and 1.57 per cent zinc, whereas samples (1544-1546) from a nearby area of mineralized siliceous breccia subcrop yielded 1.51 to 7.89 grams per tonne gold and 112.8 to 192.0 grams per tonne silver (Assessment Report 9372). Also at this time, a sample (18747) from a trench on the Ag-carbonate zone yielded 14.06 grams per tonne gold, 1600.8 grams per tonne silver, 0.72 per cent lead and 0.82 per cent zinc (Assessment Report 9372).
Later that year, further sampling of the mineralized zones yielded values of up to 0.320 per cent lead, 0.180 per cent zinc, 204.2 grams per tonne silver and 7.00 grams per tonne gold from float and subcrop samples (53926 through 53950) from the Central B zone; a sample (53918) from the Ag-carbonate area assayed 10.60 grams per tonne gold, 885.8 grams per tonne silver, 0.56 per cent lead and 0.39 per cent zinc and two samples (58636 and 61473) from a zone of quartz veining with gypsum located approximately 200 metres north-northwest of the Schmitt zone yielded 21.2 and 14.4 grams per tonne gold with 9.3 and 207.3 grams per tonne silver, respectively (Assessment Report 9833).
In 1982, three sets of channel samples were taken from trench 7 on the Ag-carbonate zone and analyzed as follows: Set 1 yielded 4.46 grams per tonne gold and 218.0 grams per tonne silver over 1.07 metres; set 2 yielded 12.00 grams per tonne gold and 717.61 grams per tonne silver over 1.53 metres and set 3 yielded 4.07 grams per tonne gold and 212.03 grams per tonne silver (Assessment Report 10739). The highest gold and silver assays were from set 2, with sample 70985 yielding 12.34 grams per tonne gold and 870.86 grams per tonne silver (Assessment Report 10739). While an in-situ sample (69321) from trench 6, located on the Schmitt zone, yielded 0.10 gram per tonne gold and 151.5 grams per tonne silver, whereas other chip samples from trenches 2, 3 and 4 on the Ag-carbonate zone yielded values of up to 2.350, 2.600 and 8.250 grams per tonne gold with 218.2, 700.0 and 260.0 grams per tonne silver over 0.5 by 1.0 metres each, respectively (Assessment Report 10739).
Also at this time, drilling on the Schmitt zone yielded intercepts including 211.0 grams per tonne silver over 26.4 metres (from 4.7 to 31.1 metres down hole), including 674.3 grams per tonne silver over 6.9 metres in hole J82-7; 177.7 grams per tonne silver over 10.5 metres (from 20.0 to 30.5 metres down- ), including 521.9 grams per tonne silver and 0.90 gram per tonne gold over 1.3 metres in hole J82-8; 75.1 grams per tonne silver over 39.9 metres (from 3.2 to 43.1 metres down hole) in hole J82-11; 340.9 grams per tonne silver over 22.45 metres (from 20.40 to 42.85 metres down hole), including 3000 grams per tonne silver and 5.50 grams per tonne gold over 0.55 metres in hole J82-12 (Assessment Report 10739).
Diamond drilling on the Ag-carbonate zone yielded intercepts including 0.87 gram per tonne gold over 19.35 metres (37.90 to 57.25 metres down hole), including 8.80 grams per tonne gold over 1.35 metres in hole J82-1; 5.80 grams per tonne gold and 16.0 grams per tonne silver over 0.25 metre (20.6 to 20.85 metres down hole), 1.40 grams per tonne gold and 26.6 grams per tonne silver over 21.1 metres (33.9 to 55.0 metres down- hole) in hole J82-2 and 1.3 grams per tonne gold and 8.0 grams per tonne silver over 12.65 metres (47.60 to 60.25 metres down- hole), including in hole J82-3 (Assessment Report 10739).
Diamond drilling on the Central B zone yielded intercepts including 131.3 grams per tonne silver and 0.23 gram per tonne gold over 76.6 metres (from 3.05 to 79.65 metres down hole), including 272.3 grams per tonne silver and 0.81 gram per tonne gold over 16.4 metres in hole J82-13; 136.1 grams per tonne silver and 0.31 gram per tonne gold over 63.5 metres (from 6.0 to 69.5 metres down hole), including 95 grams per tonne silver and 8.70 grams per tonne gold over 1.1 metres in hole J82-14; 98.6 grams per tonne silver and 0.35 gram per tonne gold over 105.75 metres (from 3.05 to 108.8 metres down hole), including 61.2 grams per tonne silver and 4.89 grams per tonne gold over 6.3 metres in hole J82-15 and 164.0 grams per tonne silver and 0.19 gram per tonne gold over 91.95 metres (from 3.05 to 95.0 metres down hole), including 216.6 grams per tonne silver and 1.08 grams per tonne gold over 12.4 metres in hole J82-16 (Assessment Report 10739).
In 1988, a grab sample from the Ag-carbonate zone analyzed 37.05 grams per tonne gold and 1049.2 grams per tonne silver, whereas channel samples from trench JD88-33 yielded 3.36 grams per tonne gold and 175.1 grams per tonne silver over 20.0 metres and 2.70 grams per tonne gold and 523.5 grams per tonne silver over 8.0 metres in trench JD88-35 (Assessment Report 18015).
In 2012, samples from the Schmitt, Ag-carbonate and Central B zones yielded 18.9, 5.5 and 14.8 grams per tonne gold and 300, 187 and 910 grams per tonne silver, respectively (Assessment Report 33556).
In 2013, a drillhole (JD-13-024), located near the eastern end of the Central B zone, yielded 1.75 grams per tonne gold and 38.1 grams per tonne silver over 12 metres, whereas a rock sample of hematite breccia outcrop (170942) from the Schmitt or Ag-carbonate zone yielded 1.25 grams per tonne gold and 510 grams per tonne silver (Assessment Report 34762).
Work History
The most extensive work on the JD West occurrence took place during 1980 through 1984, when Kidd Creek Mines Ltd. conducted programs of geological mapping, trenching, geochemical sampling, geophysical surveys and diamond drilling on the area.
Recent work history in the area included rock and soil sampling in 2012 by Tower Resources and aeromagnetic surveying by Duran Ventures in 2008. The 2008 airborne magnetic survey in the area referred to as Grid 1 extends from the area of the Creek zone (and generally associated Schmidt and Woof high-grade vein targets) northward into a cluster of magnetic responses suggesting a high-level intrusive system Duran's 2008 program reported gossans of interest in this sector.
Refer to JD-Finn (MINFILE 094E 171) occurrence for and completed exploration summary on the JD property.
