Greenstone hits it out of the park with Mt Thirsty cobalt, nickel and scandium intercepts

Greenstone is on a tear after drilling returned outstanding cobalt, nickel and scandium results from its Mt Thirsty joint venture project near Norseman, Western Australia.

The discovery of scandium, which was not previously assayed for, is encouraging as its oxide is priced at US$930,930 ($1.33m) per tonne due to its scarcity and importance in research use and hydrogen fuel cells.

Greenstone Resources’ (ASX:GSR) drilling identified three distinct zones of mineralisation were identified – an upper nickel-cobalt-manganese-scandium horizon, a middle platinum group element (PGE) horizon, and a lower nickel horizon – with hole MTRC011DA returning the sixth best cobalt intercept in Australia for 2022.

Notable intercepts in each of the zones are:

Upper zone – 15m grading 0.45% cobalt, 0.91% nickel, 5.42% manganese and 40.9

grams per tonne (g/t) scandium from a down-hole depth of 45m (MTRC011DA);

Middle zone – 9m at 0.14g/t 3E PGE, 0.09% nickel and 0.02% copper from 223m; and
Lower zone – 21.8m at 0.28% nickel and 49.8g/t scandium from 268.2m (MTRC009D).

Assays are still pending for 17 holes targeting the upper zone, four holes in the middle zone and five holes in the lower zone.

Options to consolidate the ownership structure of the Mt Thirsty JV to support an initial public offering are also being considered.

“These most recent results continue to highlight the prospectivity of the Mt Thirsty project and, importantly, the suite of target commodities, all of which serve to play a critical role in the continued decarbonisation of our economy,” managing director Chris Hansen said.

“Importantly, three discrete zones of horizontal mineralisation have now been defined, with the confirmation of a lower, and potentially higher-grade Ni-Co-Mn-Sc zone outside of the existing resource, serving to potentially complement a number of the other optimisation opportunities currently under consideration for the existing Mt Thirsty resource and PFS, including the use of high-pressure acid leaching, the addition of a cathode precursor plant and the recovery of other elements like manganese and scandium.”

He added that while the joint venture with Conico (ASX:CNJ) had yet to intersect high-grade PGE mineralisation, similar to the neighbouring Callisto deposit, it has nonetheless intercepted the target horizon and high anomalous PGE mineralisation in a number of holes.

“Furthermore, as the exploration campaign has evolved over the past months, we have gained a much better understanding of the local controls on mineralisation, having more recently focussed our attention on potential structural traps serving to accumulate sulphides,” Hansen added.

Drill results

The Phase 1 drill program was focussed on testing the deeper ultramafic sill horizons at Mt Thirsty, including any potential extensions to the recent palladium-platinum-gold-copper-nickel Callisto discovery by Galileo Mining (ASX:GAL) less than 200m from the project’s northern tenement boundary.

The upper zone consists of a weathered ultramafic peridotite rock hosting nickel-cobalt-manganese-scandium mineralisation with the most recent drilling confirming the presence of a lower and potentially higher-grade section which is currently outside of the existing resource and supported by historical drilling.

This is thanks to the use of both reverse circulation and diamond drilling allowing holes to be drilled to a depth of about 350m, significantly deeper than the holes drilled by aircore rigs at Mt Thirsty in the past.

Additionally, the current drill campaign employed a comprehensive multi-element assay suite, serving to identify the presence of scandium which had not previously been assayed for and is not included within the existing resource estimate.

The middle zone consists of an intrusive gabbro sill hosting anomalous Callisto-style palladium-platinum-gold-copper-nickel mineralisation while the lower zone consists of a chromium rich basalt hosting a thick zone of continuous nickel mineralisation.

This article was developed in collaboration with Greenstone Resources, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.