The Coral occurrence is located 3 kilometres southeast of Mount Burden and 92 kilometres north of the town of Mackenzie, approximately 15 kilometres north of Peace Reach (Williston Lake).
The showing occurs in Paleozoic Ancestral North America terrane platformal carbonates. Ordovician Skoki Formation, Silurian Nonda Formation, Silurian to Devonian Muncho-McConnell Formation and Lower and Middle Devonian Stone Formation and Middle Devonian Dunedin Formation carbonates, overlain by Devonian and Carboniferous Besa River Formation limy shale and Lower Carboniferous Prophet Formation cherty dolomite, are exposed in a folded thrust plate east of Mount Burden. West of Mount Burden, Cambro-Ordovician Kechika Group clastics and carbonates and Skoki and Nonda formation carbonates comprise the Mount Burden anticlinorium.
Red and yellow sphalerite with minor galena and pyrite disseminated in Dunedin or (upper) Stone formations dolomite breccia comprise the showing. The sphalerite and galena is commonly disseminated in dolomite fragments and in a white sparry dolomite matrix. The mineralization is hosted in an irregular zone of dolomite breccia with a 400-metre diameter surface expression. A sample of weathered rubble from a 1-metre trench excavated in 1984 assayed 1.45 per cent lead and 3.47 per cent zinc (Assessment Report 13724). The dolomite breccia is probably the same unit that hosts the Coral #2 occurrence (094B 021) located 1.6 kilometres to the west.
Mineralization comprises variable proportions of sphalerite, galena and pyrite in brecciated dolostone host rocks. Some oxidized secondary minerals, such as zinc and lead carbonates in addition to limonite/goethite may be present. Sulphide minerals range from trace quantities to more than 10 per cent. In the south end of the cleaned-out HDC Trench No. 1 is a zone of massive gossan composed essentially of limonite but with discrete visible grains of galena and pyrite glittering within it. Further north up the same trench is a face on the west side of the trench from which several slabs were sawn which display a classic coarse dolostone breccia with large patches of red sphalerite and lesser honey-yellow sphalerite and minor blebs of galena. It is evident from inspection of numerous fresh samples from HDC Trench No. 1 and the downstream outcrop sampled in summer 2016 that the simple paragenesis includes two generations of sphalerite. The predominant generation, at least along the Hound Dog Creek zone, is a fine-grained wine-red variety. Late sparry dolomite infills the breccia and may contain a generally less abundant but coarser sphalerite. This second generation is pale honey-yellow and, being very pale, is presumed to carry a significantly lower iron content. In 2016, a rock grab sample (A22515) from HDC Trench No. 1 assayed 2.37 per cent zinc and 0.014 per cent lead (Assessment Report 36370).
One outcrop, Showing No. 2, was located approximately 50 metres downstream from the original HDC Trench No. 1, which was on the southeast bank of the creek. After considerable cleaning, it was determined to be about 7 metres long and 1-2 metres high displaying variable amounts of disseminated red and honey sphalerite. This was channel sampled for its 7.0 metre horizontal length at 0.5 to 1.0 metre intervals. Samples yielded an average grade of 0.94 per cent zinc over 5.0 metres (including an interval of 2.33 per cent zinc over 1.5 metres) (Assessment Report 36370).
The discovery of the Robb Lake deposit (094B 005) in the early 1970s and its identification as a Mississippi Valley-type deposit resulted in a huge exploration effort covering hundreds of square kilometres of the northern Rocky Mountains. During that exploration, a Union Oil geologist identified a zinc-lead-silver-rich gossan on a spur east of Mount Burden, named by him as the Poco showing (094B 007). This showing is about 3.4 kilometres north of the Coral showings (094B 008). Union Oil and Brinco subsequently joint ventured the exploration of the area and undertook mapping and prospecting in the area of the Poco showing which revealed two more such showings on strike but further north over a strike extent of more than 1 kilometre. All these showings are well above treeline, though continuity may be obscured by talus slopes. In addition, they undertook a drainage geochemical survey of some of the creeks below the treeline and one creek yielded a strong anomaly. Thereafter, there was no activity until the 1980s when Harper and Manns orchestrated the staking of claims over the area on behalf of Northgate Exploration Ltd., and initiated a search for a source of the drainage anomaly below the treeline. Their efforts lead to the discovery of a very large and strong soil geochemical anomaly covering a gently sloping, dipslope, hillside several kilometres south from the Poco showing. Close to the geochemical soil anomaly an outcrop of zinc mineralization was discovered downslope in a creek which joins the anomalous creek. Trenching adjacent to this showing and subsequent packsack drilling in 1987 and 1988 all confirmed the existence of zinc and lead mineralization in a dolostone hostrock.
This large zinc geochemical anomaly and associated drillholes, mineralized trench and outcrops are referred to as the Hound Dog Creek zone or HDC zone in recognition of the location of the original showings. Since 1988, there has been little additional work, even though the area has been held under claims by various owners for short periods.
In 1999, Boliden staked the area and undertook geochemical surveys to confirm the Hound Dog Creek zone, which they did and also extended the zone another 200-300 metres along strike.
In June 2015, Minfocus Exploration Corp., by agreement with the claim owners, undertook an initial reconnaissance program, relocating the trench in Hound Dog Creek and resampling it, as well as prospecting and mapping in the area. A crew was helicoptered in to the property area and spent the first two days repairing and reinforcing the helipad near the trench on Hound Dog Creek, brushing out the landing zone, cleaning out the trench, extending it to the north by 2 metres and to the south by 0.5 metre and rock sawing channel samples.
In 2016, Minfocus Exploration completed a field program comprised of prospecting and diamond drilling. Nine diamond-drill holes were completed aggregating 514.50 metres. Zinc-lead mineralization was intersected in most of the holes with drillhole C16-9 exhibiting the most abundant mineralization including a short interval of massive sulphides. Prospecting and geological mapping continued during the period of diamond drilling.
The Minfocus 2015-2016 fieldwork, and research enabled by that work, plus the LiDAR survey in late 2017, have together added substantially to the knowledge (showings, soil and stream-sediment surveys) accumulated in the three earlier phases of exploration at Coral. Widespread zinc values seen across the Coral property include: rock samples on Poco Ridge, soil anomaly, two showings and sphalerite ± galena in drill core at Hound Dog Creek, and strong, extensive stream-sediment anomaly in Tangle Creek. The LiDAR results show multiple linear features suggestive of collapsed areas in the carbonate host rocks.
