Key Highlights

  • The scoping study examines feeding high-grade underground ore from Challenger to a recommissioned Central Gawler Mill.
  • An October 2026 resource update more than doubled Challenger’s underground resources to 230,000 ounces.
  • The updated underground resource grades 3.65 grams per tonne gold.
  • The study runs alongside the tailings-based definitive feasibility study.

Barton Gold (ASX:BGD) has started a scoping study into feeding high-grade underground ore from its Challenger gold project in South Australia to a recommissioned Central Gawler Mill. The company says the study was expedited after an October 2026 resource update more than doubled Challenger's underground resources to 230,000 ounces at 3.65 grams per tonne gold.

SRK Consulting, which is already working on Barton's definitive feasibility study, will lead the work and has completed significant preliminary modelling. Managing director Alexander Scanlon said the company had been pleasantly surprised by its detailed remodelling of Challenger's high-grade underground mineralisation, and that the fully permitted mill offered valuable infrastructure leverage.

Where the extra underground ounces came from

Part of the increase came from reclassifying mineralisation previously modelled as open-pit material to underground, with a view to more selective mining. Barton reports that this produced material grade improvements.

The underground resource comprises 1.75 million tonnes at 3.68 g/t for 207,000 ounces above the 215-metre reduced level, of which only 17,000 ounces is Indicated and 190,000 ounces Inferred, plus 23,000 ounces of Inferred material at Challenger Deeps. That confidence profile is important. Inferred resources carry low geological certainty, so any scoping study relying heavily on them will itself be low-confidence and cannot support an Ore Reserve.

SRK's preliminary modelling also points to a significant Volume of high-grade mineralisation that has been drilled but not yet infilled or classified, which could potentially be added through further near-mine drilling.

Advantages of an old mine

Challenger produced more than one million ounces of gold between 2002 and 2018. Almost all of the current underground resource lies on or next to existing serviceable development, including dual declines, and the company describes the ground as very stable. Existing access can reduce the Capital and time needed to restart mining, although old workings also bring rehabilitation and dewatering requirements.

Tailings as a starting point

The tailings deposits are a notable part of the resource. TSF1 holds 3.19 million tonnes at 0.54 g/t for about 56,000 ounces and TSF2 a further 5.13 million tonnes at 0.31 g/t, both Indicated. Tailings reprocessing generally needs less Mining but depends on recoveries. Total Challenger resources stand at 11.2 million tonnes at 1.03 g/t for about 370,000 ounces.

How it fits the wider plan

Barton's definitive feasibility study is targeting an initial three to four-year Stage 1 operation using only higher-grade historical tailings from tailings storage Facility 1 and limited near-surface material, without disturbing the underground mine. Preliminary analyses support recommissioning the mill and suggest reprocessing TSF1 material is technically feasible.

The scoping study tests whether underground ore could be added to that baseline. Barton also sees potential feed from its Tarcoola and Wudinna gold projects and the Tolmer silver project, where geological modelling is under way. The company describes itself as a developer targeting 150,000 ounces of gold a year in future, with 2.3 million ounces of gold and 3.1 million ounces of silver in resources, and full ownership of the region's only gold mill.

That production target is an aspiration that would require multiple feed sources to be proven. The Stage 1 tailings operation is far smaller.

Next steps

No completion dates were given for the scoping study, the feasibility study or the Tolmer modelling. Follow-up drilling will focus on infill and extension at the new Challenger 3 deposit and Challenger SSW, aiming to convert open-pittable material to Indicated status as baseline feed, as well as the Challenger Main pit, where recent drilling found high-grade zones up to 170 g/t in the pit walls. Underground drilling is also planned to convert unclassified material.

Scanlon said the company looked forward to the study's implications for the optimal pathway of its Challenger assets. The feasibility study outcome remains the more important near-term milestone.