American West Metals says it has defined more solid evidence of a possible giant copper deposit at its Storm project in Canada’s Nunavut territory, with two deep diamond holes boring through a respective 21.3m and 99.2m of visible copper.
The drilling of seven deep diamond holes to date have all intersected the company’s prospective target horizon at depth – stretching 10 square kilometres – and all have revealed copper mineralisation. Management believes it highlights the project’s potential to host large-scale stratigraphic and structurally-hosted high-grade copper deposits that could be similar to those in the Central African Copperbelt.
American West’s first two completed deep diamond holes for 2024 build on last year’s successful program, steadily fleshing out a picture of thick copper intercepts that exhibit visible copper in more enriched zones. Analyses for the two recent holes are not yet available, but are expected to be returned within a fortnight.
However, management says the first hole’s combined 21.3m of visual copper mineralisation includes 6.37m of visible copper sulphide from 293.7m and 2.43m of strong visible copper sulphide from 302m. It also picked up a further 12.5m of visible copper sulphide from 311m including 4.6m of strong visible native copper and copper sulphides from 315.4m.
The second hole cored out a combined total of 99.2m of visible copper sulphides, including highlights of 1.1m of strong visible copper sulphide from 195.5m, 1.3m of strong visible copper sulphide from 204m downhole and 17.1m of moderate-to-strong visible copper sulphide from 404.3m.
American West Metals managing director David O'Neill said: “Visual results show both drillholes have hit thick zones of copper mineralisation. Seven out of seven deep drill holes have intersected the prospective target horizon with copper in all holes. Every fault, every space, every gap in the rocks that we hit within the deep horizon, has copper in it.”
Both of the company’s latest holes were drilled to further test its conceptual sediment-hosted target it has dubbed the “Deep Copper Horizon”, where high-grade copper sulphides at deeper stratigraphic levels were first identified last year.
The first hole tested the southern side of the northern graben fault abutting the Cyclone deposit. A recent previous reverse-circulation (RC) drillhole close to the same location nailed 15.2m at 1.4 per cent copper and 2.4 grams per tonne silver from 103.6m including 6.1m at 2.7 per cent copper and 2.7 per cent silver from 108.2m.
The mineralisation and stratigraphy in the recent first diamond hole appears to be similar to that encountered in previous deep exploration drillholes at Storm, which points to a potentially extensive prospective copper horizon. Management says the hole confirms both shallow and deeper mineralisation in the relatively-unexplored central graben, which will now become a new key target for follow-up drilling.
It also views the ubiquitous presence of visible copper mineralisation in the second hole as a genuine pointer to the likely scale of the copper system at Storm.
American West has completed its phase-one electromagnetic moving loop geophysics (MLEM) and has identified 10 new priority shallow targets, which will be tested by initial RC drilling. A phase-two MLEM program to identify deeper targets in the Storm area has now also been finished, using bigger loop dimensions of 400m by 400m, and was optimised to screen targets lying between about 200m and 500m depth.
Management says the survey has identified five strong EM anomalies in favourable locations in the graben structural framework. Two of them coincide with known high-grade copper sulphides at Cyclone and the recently-discovered Gap prospect, while other anomalies have shown up in untested areas south of the southern graben fault.
The company says it is finding that the scale and strength of some of the new anomalies and the low false positive rate when using its MLEM systems at Storm makes them compelling targets that are now being tested by drilling.
American West is continuing its RC drilling at Storm, with its track-mounted drill rig testing resource extensions and high-priority geophysical targets, while its fly RC drill rig is drilling at the Tempest prospect. The company has already kicked off the drilling of its third diamond exploration hole at Storm, while its deep MLEM surveys are committed to the Tornado and Blizzard prospects.
The Storm project is highlighting abundant copper targets on both fault margins of the graben and is now also looking at possible stratigraphic, sediment-hosted deeper mineralisation. Management says the proliferation and volume of copper mineralisation is suggesting that Storm has a long-lived, robust mineral system with the potential for tier-one scale and that zeroing in on the strongest parts of the mineralisation will now be its prime deep exploration focus.
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By Doug Bright
