ASX-listed Legend Mining has kicked off a regional exploration program at its Rockford project in Western Australia’s famed Fraser Range. The diamond drill rods are now spinning into nickel-copper prospects along the western structural corridor with four holes, totalling 1800m, to be punched into the Magnus and Octagonal intrusive complexes. Another 100 aircore holes will be ploughed into regional targets to test geophysical and geochemical targets.
Interestingly, the western structural corridor hosts the famous Nova and Silver Knight deposits to the south-west.
The Rockford project area comprises 3088sqkm of under-explored prospective Fraser Range terrain south-east of Kalgoorlie-Boulder. Legend made a significant find in 2019 with a mineralised intrusion at Mawson on the eastern side of the project area and is now taking aim at the western corridor at Magnus and Octagonal before moving south to test the Crean and Hurley prospects.
The company is eyeing targets with similar characteristics to the Nova nickel-copper deposit within the same structural corridor 150km to the south-west. Both the Magnus and Octagonal prospects have been targeted on “eye” shaped features in regional aeromagnetic data. The prospects also contain mafic or ultramafic intrusive host rocks, another key component in the company’s search for magmatic nickel-copper-cobalt deposits.
Legend Mining Managing Director, Mark Wilson said: “The commencement of the regional program for this year is an exciting milestone for the Rockford project. The diamond drilling at Magnus will be the first ever into the Magnus intrusion and will be the first diamond drilling by Legend at Octagonal.”
The Magnus intrusion was identified by preliminary aircore drilling over the aeromagnetic feature that unearthed a fractionated norite intrusive suite surrounded by highly magnetic country rocks. The diamond drill holes have been targeted on gravity highs over known intrusions with coincident elevated nickel-copper results.
At Octagonal, previous aircore drilling over the magnetic feature also hit prospective nickel-copper intrusive host rocks, including norite, gabbronorite and peridotite. Reverse circulation and diamond drilling then intersected multiple intervals of massive, semi-massive and disseminated sulphides associated with the intrusives. The company believes the mineralisation identified so far demonstrates all the characteristics of a fertile magmatic nickel-copper sulphide system.
It says Octagonal is one of only four publicly disclosed massive nickel-copper sulphide occurrences in the Fraser Range.
The eastern margin of the Octagonal intrusive complex has been targeted with the first diamond hole testing a down plunge geochemical anomaly and geophysical response. The second diamond hole planned at Octagonal will be aimed at the contact between the intrusive and metasediment.
The aircore drilling program will test a combination of aeromagnetic and gravity features and will also follow up previous anomalous results, including holes that hit 12m going 0.10 per cent nickel from 32m and a lengthy 47m intersection grading 0.19 per cent nickel from 24m.
Infill drilling at Octagonal is planned around a hole that encountered a thick ultramafic intrusive, intersecting 59m at 0.12 per cent nickel. The company will also take aim at a recently identified untested gravity high to the immediate southwest of the Octagonal magnetic “eye”.
Legend plans to have geophysical downhole electromagnetic surveys completed in all diamond holes. The company expects to have both the diamond and aircore drilling programs wrapped up in six weeks.
The company has its saddle bags full and plans to spend more than $4 million on regional exploration this year whilst it smashes out a 10,000m drilling campaign this season at Rockford.
Legend also recently reported continued growth of the mineralised footprint at its Mawson project with the latest drilling and interpretation pegging the intrusive at 3km by 1.2km and still open in all directions. Significantly, three massive nickel-copper occurrences have been identified within that area and stand-out intercepts include an impressive 31.1m going 2.80 per cent nickel, 2.04 per cent copper and 0.15 per cent cobalt.
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