The Koopatoo occurrence is located 5.8 kilometres south-southwest of Bowser Lake approximately 50 kilometres north of the community of Stewart.
In the Koopatoo showing region, the Middle to Upper Jurassic upper Hazelton Group is referred to as the Iskut River Formation which occurs through the central and eastern parts of the Bowser property. The formation includes bimodal volcanics, as well as porphyritic intrusions and debris flows. The Iskut River Formation is capped by black carbonaceous pyritic mudstone interbedded with a light and dark banded tuffaceous siltstone, which are distinct in the region and referred to as the Quock Member (Formation) (formerly known as the “pyjama beds”) (Fieldwork 2017).
Three samples within 125 metres of each other assayed 3.1 grams per tonne gold, 3.74 grams per tonne gold, and 0.47 gram per tonne gold. Samples that were enriched in gold generally have an association with pyrite. Sample B072122 assayed 3.74 grams per tonne gold, 63.7 grams per tonne silver, 0.27 per cent zinc, 0.02 per cent lead, 0.76 per cent arsenic, and 0.29 per cent antimony (Assessment Report 37435). This sample was described as a quartz-carbonate vein with pyrite, sphalerite, arsenopyrite, and stibnite. The vein was reported to appear sheeted with local comb textures; sulphides occurred in the vein core. Rock samples in the immediate vicinity were reported as mafic volcanic rock, lapilli tuff and/or sandstone.
In 2017, Pretium Exploration conducted grassroots prospecting, sampling and mapping on their Bowser property, mostly southwest and south of Bowser Lake. They collected 2901 rock and 429 silt samples (Assessment Reports 37435, 37443). Several new MINFILE occurrence are documented and a number previously documented occurrences were visited by Pretium.
In 2018, beyond the Brucejack mine area (104B 193), Pretium continued to evaluate their surrounding 1250 square kilometres of mineral claims. From July to October, 31 diamond-drill holes totalling 7725.1 metres were completed on the Bowser property; 10 holes tested the Lilliane (104A 112), 2 holes tested the Moonlight (104A 005), 9 holes tested the Bluffy (104B 075), 1 hole tested the Virginia K (104A 118), 3 holes tested the Outlaw (located 1.3 kilometres north of Moonlight Glacier 1 (104A 120), 4 holes tested the Haimila (104A 226), and 2 holes tested the Ridgeback (located 1.9 kilometres west of Koopa Bowl (104A 233). The exploration targets were widespread and drillholes targeted epithermal, porphyry copper, shear zone-hosted gold, and volcanogenic massive sulphide (VMS) style mineralization. The company also carried out mapping and prospecting (Assessment Report 38235).
As of September 2019, two drills were testing the high-priority A6 zone volcanogenic massive sulphide (VMS) target located 14 kilometres northeast of Brucejack mine; a third drill targeted a VMS system at the Canoe zone (104B 732, 734) located 15 kilometres west-southwest of Sharktooth; and a fourth drill targeted an intrusion-related gold system at the Koopa zone (104A 222, 229, 233) located 10 kilometres south of the Sharktooth. Drilling earlier in the summer also focussed on the Tuck zone (104B 730) located 22 kilometres west of Sharktooth and Liliane zone (104A 112) located 17 kilometres south of Sharktooth, both epithermal gold system targets.
To date (2019), approximately 26,103.1 metres have been drilled in 81 holes. To facilitate exploration work, the Bowser property has been divided into zones and the drilling took place in seven of these zones: A6 Anomaly, Canoe, Koopa, Tuck, Haimila, Kirkham, and Lillianne (Assessment Report 39085).
See Betty (104A 008) and Koopa Bowl (104A 233) for details of relevant work done on Pretium's grassroots project on their Bowser property, including significant property-wide geophysical surveys completed prior to to 2017. Refer also to West (104B 193), located 23 kilometres west of Sharktooth, for details of related mineralization and a common work history relating to the Brucejack project of Pretium Resources.
