The latest round of diamond drilling at Legend Mining’s Mawson nickel, copper and cobalt discovery in Western Australia’s Fraser Range has hauled in massive nickel sulphides from a suite of prospective host rocks.
Legend’s probe with the diamond drill rig is designed to chase up a swag of valuable targets identified from a recently completed detailed 3D seismic survey that covered a 6.5 square kilometre area of the prospect.
Management says 3D seismic data was famously instrumental in the discovery of the nearby Nova Bollinger nickel and copper mine that boasts a 14.3 million tonne resource grading a generous 2.3 per cent nickel and 0.9 per cent copper.
The 3D seismic data maps the mineralised Mawson intrusion in drilled areas down to 500m below surface and the company says the data indicates it could extend below the Mawson fault to possibly 800-1000m depth.
Legend’s application of the exploratory technique at Mawson looks to be paying dividends, with the two latest diamond drill holes intersecting heavily disseminated and massive sulphides at depths that are consistent with the geological interpretation of the seismic data.
The third hole, from the five-hole program, pierced the mineralised mafic intrusive as expected above the Mawson fault. Further investigation below the fault revealed an array of metasedimentary units and mafic intrusive rocks with narrow cross-cutting veins of massive sulphide mineralisation.
Encouragingly, drilling also encountered a prospective ultramafic unit with a zone of heavily disseminated magmatic sulphides at roughly 751m down hole.
A further 1km north-west along strike of the mapped mafic intrusion, the fourth hole was aimed at interrogating the prospective mineralised intrusion below existing RC drilling.
Geological logging has confirmed the mineralised mafic intrusive package was intersected over a wide zone extending to depths as predicted by the 3D seismic data. The mafic intrusive rocks form as cross-cutting dykes into the metasedimentary sequence.
Importantly, Legend says the metasedimentary collection contains an abundance of carbonate and is the first time it has been identified at Mawson.
A zone of roughly 1m of massive magmatic sulphides with intense carbonate digestion was also reportedly intersected at 450m down hole.
The company says the massive sulphide intercept is evidence of carbonate horizons acting as preferential mineralisation traps and again makes the link to WA giant by pointing out that such formations are also a key signature of the Nova and Bollinger orebodies.
Drilling is continuing at Mawson with the fifth and final drill hole of the program.
All diamond drill holes will be followed up with a suite of downhole surveys, including electromagnetic geophysical surveys and petrophysical property measurements that will aid the in refining existing modelling as it looks to prove up the next round of drilling targets.
The Mawson prospect is within the company’s Rockford project that covers more than 3000 square kilometres of tenure within the celebrated Fraser Range, about 250km east of Kalgoorlie.
The region came to prominence almost a decade ago after Sirius Resources’ Nova-Bollinger nickel, copper and platinum discovery about 120km away.
Whilst the nickel price has taken a spell from its recent lofty heights, the demand for the base metal has not. According to S&P Global, the stainless-steel industry accounts for just over 70 per cent of nickel consumption while batteries take up a modest 5 per cent. The surge in the electric vehicle market has some predicting the figure to increase to 35 per cent of total demand by the end of the decade.
Legend’s investigations into its Mawson nickel, copper and cobalt discovery look to be piecing together an intriguing puzzle, with several key zones exhibiting uncanny similarities with its Nova-Bollinger neighbour. Time will tell how the part Legend will play in meeting rising base metal demand.
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By Matt Birney
