The Taurus II (Oro vein) occurrence is located north of McDame Lake in northern British Columbia, 115 kilometres southwest of Watson Lake, Yukon, and 120 kilometres north of Dease Lake, British Columbia. Access to the property is via Highway 37, which connects to these towns. The abandoned town of Cassiar is at the northwestern end of the property, and the unincorporated settlement of Jade City is on Highway 37 at the road entrance to the mine facilities.
Upper Paleozoic Slide Mountain Complex mafic volcanic rocks are the most widespread and crops out over most of the property area. The volcanic rocks comprise massive and pillowed basalt with rare chert intercalations with the lower portion in the Taurus area (MINFILE 104P 012) marked by magnetite and jasper-rich basalt. The non-magnetic and non-jasper–bearing basalt sequence hosts most of the vein systems in the camp and has been the focus of exploration. Upper Triassic Slide Mountain Complex rocks of the middle thrust sheet cap basalt of the lower thrust sheet and crop out extensively in the southern portion of the camp on Table Mountain and in the northern portion of the camp where they locally form thin klippen. The rocks comprise thin-bedded slaty siltstone, sandstone, calcareous mudstones, and grey limestone with rare veins. A thin discontinuous sheet of ultramafic rocks occurs at the base of this thrust sheet. The sheet locally thickens to large bodies in the order of hundreds of metres. Near vein systems, these ultramafic rocks are altered to a quartz-carbonate-fuchsite assemblage, referred to as listwanite.
The Oro vein structure and related Oro South structure are western extensions of the vein system encountered in the Trench 3 area and occur beneath the sediments and the listwanites occupying the thrust plane. The structures strike 090 degrees and dip 70 degrees south approximately normal to the thrust plane and have been defined over a strike length of 230 metres. The Oro vein and attendant mineralized wallrock intervals have an average core length of 7 metres translating to 3.5 metres true width. The Oro South structure, subparallel to and 10 to 15 metres into the hangingwall above the Oro structure has an average core length of 3.5 metres translating to 1.8 metres true width. Quartz veining, stringers and pyritic dolomitized wallrock are all mineralized.
The Oro occurrence has previously been referred to as the Newcoast No. 2 zone, during the 1970s and 1980s and later as the North Notch area during the late 1990s and early 2000s. Another zone of mineralization, referred to as the Newcoast No.3 zone, is located adjacent to the south bank of Troutline Creek and approximately 150 metres south-southeast of the main occurrence.
In 1984, a chip sample (P3157) from the No.2 (Oro vein) zone yielded 2.5 grams per tonne gold and 341 grams per tonne silver over 0.07 metre, whereas samples from a nearby trench yielded an average of 1.2 grams per tonne gold and 97.4 grams per tonne silver over 3.7 metres (Assessment Report 12627).
In 2006, an initial three diamond drill hole fence (06TII-01, 06TII-02, 06TII-03) 70 metres west of the vein exposure in trench 3, intersected and defined dip geometry on the structure. The Oro vein has an average core length of 1.9 metres on this section and contains trace to 1 per cent chalcopyrite, sphalerite, and tetrahedrite. The absence of coarse ‘clotty’ pyrite, typical of high-grade veins in the Table Mountain area of the property, was apparent. Assays from several narrow, intensely dolomitized, stringered, and pyritized, volcanic intervals intersected in hole 06TII-03 yielded gold grades in the sub-gram range over 1.8 to 3.5 metres core length.
Drillhole 06TII-04 was designed to intersect the structure 100 metres west of the initial fence assuming a strike of 110 degrees. The hole overshot the Oro vein target in the argillite cap by approximately 20 metres but intersected a pair of subparallel (?) quartz stringer zones approximately 115 metres north of the Oro vein plane that yielded 1.56 grams per tonne gold over 1.8 metres and 0.52 gram per tonne gold over 3.95 metres core length, respectively. Hole 06TII-05 was drilled approximately halfway between the initial fence and hole 06TII-04. The hole intersected what is interpreted to be the Oro vein at the thrust contact. The vein has a core length of 3.45 metres and contains trace to 0.5 per cent chalcopyrite, sphalerite and tetrahedrite. With the exception of a single 3.04-gram-per-tonne gold assay yielded by a 0.5-metre sample interval containing 3 per cent coarse clotty pyrite, the vein is barren. Hole 06TII-06 targeted a further step-out to the west from hole 06TII-05 (80 metres west of the original section) intersected a quartz vein breccia containing 5 per cent coarse subhedral to euhedral pyrite is interpreted to represent the Oro vein structure. This interval yielded 0.74 gram per tonne gold over 1.9 metres core length.
Holes 06TII-07 and 06TII-08 intersected a 9.8-metre core length vein/vein breccia approximately 45 metres below the listwanite. The interval contains an average of 3 per cent coarse pyrite and traces of chalcopyrite, sphalerite and tetrahedrite where best grades were yielded by an intensely dolomitized footwall alteration zone. Holes 06TII-09 and 06TII-10 were drilled a further 30-metre west step-out from 06TII-07 and 06TII-08. Hole 06TII-09 intersected a 1.5-metre core length quartz vein/vein breccia containing 1 per cent coarse pyrite, trace chalcopyrite and trace sphalerite approximately 15 metres below the listwanite. The best grades in this intersection were also yielded by the intensely dolomitized footwall alteration zone. Hole 06TII-10 intersected a 7.8-metre core length stringer/vein/vein breccia zone containing an average of 1.6 per cent coarse pyrite that graded 0.68 gram per tonne gold over 11.15 metres core length.
Holes 06TII-11 intersected a 5.4-metre vein with 0.5 to 5 per cent locally coarse pyrite approximately 50 metres below the interpreted listwanite that, with the wallrock alteration halo, graded 1.67 grams per tonne gold over 9.05 metres core length (Assessment Report 29235).
In 2019, two rock samples (667611 and 667612) taken from the north side of Troutline Creek, approximately 300 metres east-southeast of the occurrence, assayed 2.26 and 1.88, respectively (Assessment Report 38989).
Work History
The area has been explored in conjunction with the nearby Taurus (MINFILE 104P 012) occurrence and a completed regional and property exploration history can be found there.
In 1976 and 1979, Newcoast Silver Mines Ltd. completed programs of geological mapping, soil sampling, three diamond drill holes, totalling 220.2 metres, and approximately 24 line-kilometres of ground magnetic and electromagnetic surveys on the area as the Van and Tin claims.
In 1980 and 1981, Esso Resources Canada Ltd. completed programs of prospecting, geological mapping, trenching and geochemical (rock and soil) sampling on the area as the Goldhill, Nora, Val and Van claims. An adit, referred to as the Newcoast adit, was reported on the occurrence by this time. In 1984 and 1985, Erickson Gold Mining completed programs of prospecting, geological mapping, geochemical (rock and soil) sampling, trenching and ground magnetic survey on the area as the Camp, Diane Fr. and Panda claims.
In 1995, the area was held and examined by Cusac Gold Mines Ltd. as the Table Mountain Gold property.
In 2005, Cusac Gold Mines Ltd. drilled a total of 2444 metres in 13 drillholes on their Taurus II property, in three areas: the Backyard system (MINFILE 104P 121), with six holes totalling 1140.1 metres; the Somerville system (MINFILE 104P 016), with six holes totalling 1122.5 metres, and the Porcupine East (MINFILE 104P 077), with one hole totalling 181.4 metres.
In 2006, Cusac Gold Mines Ltd. conducted a soil geochemical survey (2720 samples), LiDAR survey (139 square kilometres), trenching program (eight trenches for a combined length of 530 metres), and diamond drilling program (21 holes for a combined depth of 3280.3 metres; 843 core samples) on the Taurus II area of their Table Mountain Gold property. Twelve holes (1885.5 metres) were drilled to test the western extension of the Oro Structure exposed in the trench 3 area; five holes (586.1 metres) were drilled to test the Blue zone exposed in the trench 5 area. An additional four holes (808.8 metres) were drilled to test isolated targets in the Reo, TR-6E, and McHwy areas.
In 2007, Hawthorne Gold Corp. and Cusac Gold Mines Ltd. agreed to merge. During During 2008 through 2010, Hawthorne Gold Corp., later China Minerals Mining Corp., completed regional programs of geological mapping, geochemical (rock and soil) sampling and 11,657 line-kilometres of airborne magnetic, radiometric and electromagnetic surveys on the area as the Cassiar Gold property.
In 2019, Margaux Resources completed a program of prospecting, geological mapping and rock sampling on the area as the Cassiar Gold property. In 2020, Cassiar Gold Corp. completed a program of regional photogeological interpretation, prospecting and rock sampling on the Cassiar Gold property.
