Wiluna Mining Corporation Ltd (ASX:WMC, OTC:WMXCF) has revealed bonanza grade drilling results including 0.30 metres at 3,270 g/t gold within a broader zone of 10 metres at 2.80 g/t from the very first hole testing the Bulletin North discovery target at the Wiluna Mining Centre in WA.
The Bulletin North target is one of nine large-scale sulphide shoot targets to be tested as part of a 40,000 metres discovery program across the Wiluna mine site.
Further, high-grade results from resource development and grade control drilling at Bulletin and Happy Jack zones support geology modelling and the short-term production profile in immediate mining areas during the ramp-up in sulphides concentrate production.
Wiluna’s 1,600 square kilometre exploration tenure in the broader Wiluna region is also geologically prospective for lithium pegmatites and nickel-copper-cobalt-platinum group element (Ni-Cu-Co-PGE) mineralisation.
Grass-roots exploration has commenced with a review of historical geophysical and geological datasets and the identification of initial targets that require follow-up fieldwork.
Discovery program
Wiluna has started a 40,000-metre discovery drilling campaign to test nine targets for new high-grade sulphide shoots “under the headframe” at Wiluna.
High-grade >5g/t shoot discoveries are targeted to substantially enhance the early years of the current mining plan with the intention of increasing the underground ore grade which will support plans to grow gold production with higher grade mining areas.
The company is targeting large-scale, high-grade shoot targets like those historically mined at Wiluna, such as the Bulletin shoot that has an endowment of past production combined with the current mineral resource of about 1.5 million ounces at 7 g/t.
Wiluna Mining Centre - nine targets within the 40,000-metre discovery program.
Bulletin North target
At Bulletin North, the first of 12 holes has intersected high-grade sulphide mineralisation about 150 metres along strike to the north of the current resource limits in a modelled new shoot location.
Stoping of the historical Bulletin shoot, mined in the 1930’s to 1950’s, came to within 50 metres of the Bulletin Main shoot that lay undiscovered until 1993 and has since produced 800koz at 8g/t.
The current Discovery program tests for a repeat of the Bulletin Main shoot, in a target area from 100 to 500 metres along strike, in an area that has never been tested despite the large-scale, high-grade past production and high-grade intersections in very shallow holes at surface.
Resource development
The latest assay results comprise an additional 12 holes for 3,326 metres of resource development drilling at Happy Jack, received since the preceding drilling update on 3 November 2021.
Highlight results include 7.84 metres at 6.48g/t and 11.95 metres at 6.04 g/t.
Wiluna’s drilling program has consistently delivered thick, high-grade intercepts over the past 18 months from targeted locations at shallow depths, and close to previous development that is easily accessible for rapid low-cost production.
Drilling is ongoing with four diamond drill rigs currently underground at Wiluna as the company continues drilling to define additional resources and reserves and to fully scope out the scale of the multi-million-ounce Wiluna ore body.
The drilling program is designed primarily to infill areas of Inferred Resource within preliminary stope designs, with the aim to upgrade geological confidence to Indicated Resource category and to grow the Ore Reserve.
Additionally, extensional drilling has aimed to extend potential stoping areas along strike, up-dip and down-dip.
The Happy Jack program also shows potential for resource growth where holes have intersected the mineralised shear zone outside of the current Inferred and Indicated Resource limits.
Wiluna’s drilling has focussed on the upper 500 metres below surface, and considerable potential for resource extensions exists where the lodes remain open in at depth and along strike.
Nickel-copper-cobalt-PGE exploration
The company’s tenement holding at Wiluna is prospective for tier-1 Ni-Cu-Co-PGE discoveries.
In the mid-2000’s, high-grade nickel sulphides were drilled by previous project operators at Bodkin prospect and numerous additional sulphide prospects have been identified by Wiluna for follow-up.
Wiluna’s tenure extends along the same ultramafic belt that hosts the world-class deposits owned by BHP Group Ltd at Honeymoon Well and Mouth Keith.
The northern ultramafics at Wiluna have not yet yielded similar economic discoveries, owing in part to the focus of previous operators on gold, and multiple changes in project ownership over the past 20 years.
Lithium exploration
Wiluna had commissioned lithium exploration experts CSA Global, an ERM Group Company, to provide lithium targeting and exploration advice.
The company’s tenure is considered prospective for Lithium-Caesium-Tantalum (LCT) type pegmatites, and the discovery of Liontown Resources (ASX:LTR) Ltd’s world-class Mt Mann-Kathleen Valley LCT pegmatite group only 90 kilometres to the south of Wiluna and within the same greenstone belt adds strong empirical support.
Following a review of available regional geological and geophysical data, CSA Global selected three areas in which to focus initial exploration for LCT pegmatites.
Wiluna’s strategy is to gain maximum value for its shareholders on its non-core, non-gold assets on its large tenement package.
Given the considerable scale of the company’s gold assets at the Wiluna Mining Centre, it is likely that it will take several years before Wiluna could justify spending the time and money developing the nickel and lithium opportunities.
As part of this strategy, the exploration and assessment work Wiluna is conducting on its nickel and lithium ground is intended to assist the company in assessing opportunities to monetise these assets in the future.