American West Metals has extended the high-grade Thunder copper zone at its Storm project in Canada’s Nunavut province to more than 300m after completing 66 reverse-circulation (RC) and diamond drillholes.
The company has also received encouraging visible indications of mineralisation in its first 22 drillholes, with nine step-out holes exhibiting thick copper mineralisation to confirm the 300m strike extent of the target.
One vertical hole intersected 121.2m of visually-continuous copper sulphide mineralisation from 18.3m downhole. A second hole – about 135m east of the first – also intersected 73.2m of visually-continuous copper sulphide mineralisation from 45.7m downhole, including multiple zones of semi-massive sulphides.
American West’s discovery hole at Thunder last year bored through 48.8m at an average grade of 3 per cent copper and observations from further drilling to date – which have probed no deeper than 100m – have led the company to conclude that high-grade copper mineralisation at the target remains open along strike and at depth.
Four RC holes were put into Thunder to determine the orientation of the mineralised zone. Two of them were drilled to test for a possible northwards extension of the mineralisation and both holes intersected thick intervals of visual copper sulphides (41.2m and 38.1m, respectively).
The other two RC holes were sited about 150m south of the interpreted Thunder mineralised zone and were drilled towards the north to test for both vertical and southwards extension of mineralisation. Both holes also intersected thick intervals of visible copper sulphides (38.1m and 39.2m, respectively), with strong visible chalcocite mineralisation observed in one of the holes between about 86.9m and 90m downhole.
American West Metals managing director Dave O’Neil said: “The Thunder drilling is continuing to impress. The drilling demonstrates that there is significant potential to convert the 2023 discovery into additional high-grade resources, which will quickly grow the copper endowment of Storm.”
At the company’s main Cyclone deposit – which is estimated to comprise 12.1 million tonnes at 1.2 per cent copper and 3.8 grams per tonne silver – multiple drillholes reveal thick zones of visible sulphides. It includes some holes well outside the current resource zone, suggesting plenty of scope for increasing the grade and extent of the resource.
Management says two holes drilled off to the north-east of the Cyclone deposit have expanded the strike of mineralisation, intersecting a combined 53.4m in two zones (in one hole) and a continuous 80.7m of visible copper mineralisation in the second hole from 48.8m downhole depth, which consists of fine chalcocite veinlets and breccias.
The significance of this style of copper mineral zonation is that it appears to be typical of sediment-hosted copper systems. Moreover, both holes lie in a big untested area to the north of the current Cyclone resource and their indicated thicknesses and visual copper mineralogy are strong indicators for likely significant resource extensions northwards from the main deposit.
They are expected to be incorporated into future resource upgrades for Cyclone.
Intriguingly, at a location opposite to the extension holes, a hole was drilled about 80m south-west of the Cyclone deposit to a downhole depth of 160m in a bid to define potential extensions to the existing resources in that direction and to follow-up further west of a previous drillhole. The 160m hole intersected a single, 16.8m-thick upper zone of visible copper sulphide mineralisation containing strong chalcopyrite-dominant mineralisation that also contains chalcocite between 91.4m and 96m downhole.
A lower zone of copper oxides was also intersected.
The big south-west step-out from the current Cyclone resource and thickness of the strong visible mineralisation indicates that significant potential for south-westerly resource extensions from Cyclone may also be inferred. If both north-east and south-west extensions can be proven, the Cyclone resource may grow considerably.
American West is charging ahead with ongoing RC drilling at Storm, using two rigs to explore resource expansion and high-priority geophysical targets. It also has a diamond rig drilling both exploration and resource targets and anticipates first assay returns from its summer program within a fortnight, with more due in four to six weeks.
The company is planning to soon kick off another round of electromagnetic (EM) geophysical surveys to finalise its deep-search surveys in the immediate Storm area, before shifting to its Tornado and Blizzard copper prospects.
It is also undertaking environmental monitoring and surveying, while its process beneficiation studies on a variety of ores from the Cyclone and Chinook deposits have been completed and results are due to be released shortly.
With high-grade hits, big copper mineral thicknesses at Cyclone and abundant copper sulphide shows coming out of Thunder, The Gap and Lightning Ridge – all reinforcing the company’s structural graben model for the mineralisation – management appears to be cooking up a significant Storm in Nunavut.
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By Doug Bright
