Barton Gold Hits 53m at 2.51 g/t at Tunkillia as Resource Upgrade Nears
Key Takeaways
- Hole TKB0745 returned 53m @ 2.51 g/t Au from just 60m depth, more than double the 1.05 g/t Au average grade currently modelled for the project.
- Phase 2 infill drilling covered 38,760m across 311 holes, with TKB0724 hitting 1m @ 53.5 g/t Au inside 26m @ 2.79 g/t Au.
- The Starter Pits are modelled at about $1.8bn operating profit over 2.5 years with a 73% unlevered pre-tax IRR, though that is scoping-level work.
- A gold JORC Resource upgrade is pending against current resources of 1.6Moz Au and 3.1Moz Ag, with no date and no disclosed outcome yet.
- The PFS and silver resource update are targeted for Q1 CY27, with a Mining Lease application to follow and the environmental Scoping Report already approved.
Final Tunkillia assays deliver broad, high-grade hits across Starter Pits
Barton Gold (ASX:BGD) has received final assays from its 39,000m ‘Phase 2’ reverse circulation (RC) Resource upgrade drilling at the Tunkillia Gold Project in South Australia. RC drilling collects rock chips from the hole as it is drilled, and the chips are then tested for gold.
The headline result is hole TKB0745, which returned 53m @ 2.51 g/t Au from 60m depth. Hole TKB0724 returned 26m @ 2.79 g/t Au from 126m depth, including 1m @ 53.5 g/t Au from 129m depth. The unit “g/t” means grams of gold per tonne of rock.
Across ‘Phase 1’ and ‘Phase 2’, Barton drilled 57,653m across 520 RC and diamond drilling (DD) holes. ‘Phase 2’ made up 38,760m across 311 holes.
A gold JORC Resource upgrade is pending. The silver JORC Resource update and a Pre-feasibility Study (PFS) are targeted for Q1 CY27.
For investors, the company says the assays infill the ‘Starter Pits’ and reinforce “the central high-grade zone driving early project economics”. That zone is where the project’s early cash flow is modelled to come from.
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Standout intersections from the Phase 2 drilling
Best results at a glance
Barton highlighted seven holes from the final assays. All are reported as downhole lengths, not true widths.
| Hole ID | Interval | Including |
|---|---|---|
| TKB0724 | 26m @ 2.79 g/t Au from 126m depth | 1m @ 53.5 g/t Au from 129m depth |
| TKB0736 | 2m @ 16.75 g/t Au from 56m depth | 1m @ 32.4 g/t Au from 56m depth |
| TKB0737 | 6m @ 3.05 g/t Au from 58m depth | 2m @ 7.20 g/t Au from 58m depth |
| TKB0742 | 21m @ 4.13 g/t Au from 61m depth | 2m @ 29.9 g/t Au from 79m depth |
| TKB0745 | 53m @ 2.51 g/t Au from 60m depth | 2m @ 18.25 g/t Au from 72m depth, and 1m @ 26.3 g/t Au from 92m depth |
| TKB0746 | 17m @ 2.26 g/t Au from 116m depth | 1m @ 20.7 g/t Au from 125m depth |
| TKB0748 | 14m @ 3.80 g/t Au from 67m depth | 1m @ 8.80 g/t Au from 75m depth, and 2m @ 11.0 g/t Au from 77m depth |
Managing Director Alexander Scanlon said the results support the highest-grade results of the earlier phase and point to possible new zones.
Alexander Scanlon, Managing Director
“We are pleased with the results of Tunkillia’s ‘Phase 2’ infill assays, which support the highest-grade results of ‘Phase 1’ drilling and the potential for new, shallower zones of high-grade mineralisation within the existing ‘Starter Pits’.”
What the cross-sections show
Barton prepared representative cross-sections for three optimised open pit areas from its May 2025 Optimised Scoping Study (OSS). Key observations include:
- Area 51: a south-plunging, thick higher-grade shoot. The main lode continues approximately 250m north and 200m south, and remains open to the south and west.
- Area 223 North: significant mineralisation at (or beyond) the limits of the previous modelling cut-off and pit profile from the May 2025 OSS.
- Area 223: shallow mineralisation appears more vertically controlled, and oxidised mafic dyke mineralisation continues to within 18m of surface.
Barton says remodelling will be required in Area 223 North, and anticipates a more vertically oriented model in Area 223. That could improve the grade profile and growth potential, though no outcome has been disclosed.
Why the Starter Pits matter to the investment case
Starter Pit economics (May 2025 OSS)
The ‘S1’ and ‘S2’ pits are modelled to produce approximately $1.8bn operating profit during the first 2.5 years of operation at current gold and silver prices. That drives an unlevered pre-tax equity IRR of 73% and a capital payback period of less than one year.
The presently modelled average grade is 1.05 g/t Au. Within the total project, the S1 and S2 pits are modelled to produce 365,000oz gold and 923,000oz silver in the first ~27 months at an average cash cost of A$1,429/oz Au.
The wider OSS outlined the following:
| Metric | OSS figure |
|---|---|
| Annual production | ~120,000oz gold and ~250,000oz silver |
| NPV7.5% (unlevered, pre-tax) | ~A$1.4 billion |
| IRR (unlevered, pre-tax) | ~73.2% |
| Payback period (unlevered, pre-tax) | ~0.8 years |
These are modelled scoping-level outputs, so they depend on the assumptions behind the study.
What do infill drilling and a Resource upgrade mean?
Infill drilling places new holes between existing ones. It tests whether mineralisation is continuous and how rich it is, so the geological model rests on more data.
A JORC Resource is a formal estimate of mineralisation, classified by confidence level. Re-modelling with new drilling can change both tonnes and grade. The model underpins a PFS and the planned Mining Lease application.
Tunkillia currently holds JORC Resources of 1.6Moz Au and 3.1Moz Ag. The announcement does not disclose the outcome of the upgrade, so you should treat any change in size or grade as unknown until Barton publishes it.
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Next steps: Resource updates, PFS and approvals pathway
Remodelling of all Tunkillia gold mineralisation has commenced, using nearly 58,000m of additional drilling. A comparison with the March 2025 JORC Mineral Resource Estimate (MRE) will follow in a forthcoming update, which Barton anticipates in the near future. No date has been given.
The silver JORC MRE (a subset of the gold MRE) is expected during Q1 CY27. Barton is targeting publication of the PFS in Q1 CY27, with a Mining Lease application planned thereafter.
Tunkillia’s environmental Scoping Report was recently approved by the South Australian Department for Energy and Mines (DEM). It will establish the official terms of reference for the development approvals process.
The PFS has commenced, with work programs also underway to support it, the planned Mining Lease application and project finance conversations:
- Flora, fauna, and water surveys and monitoring
- Aboriginal and cultural heritage surveys and work program clearances
- Technical studies for tailings storage facility (TSF) and other non-process infrastructure (NPI)
- Review of potential options for financing, construction and operation of camp infrastructure
- Evaluation of prospective renewable energy solutions for reduced reliance on diesel power supply
Barton describes itself as an Australian gold developer targeting future gold production of 150,000ozpa. It reports 2.2Moz Au and 3.1Moz Ag total JORC Mineral Resources and 100% ownership of the region’s only gold mill in the Gawler Craton of South Australia.
The next catalyst to watch is the gold MRE update, which will show how the new drilling changes the Tunkillia Resource.
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