Barton Gold's Tunkillia S1 Pit: A High-Grade Catalyst for JORC Resource Upgrade and Project Finance Readiness

Barton Gold's Tunkillia Gold Project in South Australia has emerged as a compelling case study in the de-risking of early-stage gold projects. With its S1 Pit poised to transition from inferred to measured and indicated JORC (2012) resource categories, the project demonstrates a rare alignment of geological clarity, financial discipline, and strategic operational planning. For investors seeking exposure to high-grade gold assets with clear technical and regulatory milestones, Tunkillia's progress offers a blueprint for how exploration-to-production risk can be systematically mitigated.

Geological De-Risking: High-Grade S1 Pit Advances to JORC Measured/Indicated

The cornerstone of Tunkillia's appeal lies in its S1 Pit, a shallow, high-grade gold deposit that has already delivered compelling results. According to a report by , Barton Gold completed Phase 1 reverse circulation (RC) drilling for the S1 and S2 pits ahead of schedule and under budget, with 18,893 meters drilled across 209 holes. This campaign targeted the conversion of mineralisation to JORC (2012) "Measured" and "Indicated" categories, a critical step for project financing and reserve estimation.

The S1 Pit's central zone hosts a 300-meter-long, 80–100-meter-wide corridor of bulk open-pittable mineralisation, with historical assays including 10 meters at 15.7 g/t Au from 54 meters. Such grades underscore the deposit's potential to generate robust operating cash flows. update notes that the S1 Pit is projected to yield 206,000 ounces of gold at a cost of A$997 per ounce, generating over A$800 million in operating cash and repaying development costs more than twice over in the first year of operations. These metrics position Tunkillia as a high-margin asset in a sector where all-in sustaining costs often exceed A$1,500/oz.

Financial Viability: A$1.4 Billion NPV and Path to Production

The project's economic strength is further reinforced by an optimized scoping study released in May 2025. This study outlined a potential 942,000 ounces of payable gold and 2 million ounces of silver, with an average all-in sustaining cost of A$2,222/oz and an unlevered pre-tax net present value (NPV) of A$1.4 billion according to the study. While these figures are preliminary, they reflect the scalability of Tunkillia's resource base and its compatibility with low-cost processing via the nearby Central Gawler Mill (CGM).

Barton Gold is currently advancing a Definitive Feasibility Study (DFS) for the CGM, led by Altris Pty Ltd and supported by SRK Consulting and Tetra Tech Coffey. The DFS aims to leverage the mill's existing permits to process historical tailings (Phase 1) and transition to fresh ore (Phase 2) by late 2026. This "brownfield" approach minimizes regulatory and environmental risks, a critical advantage in an industry grappling with rising ESG scrutiny.

Regulatory and Environmental Progress: A Low-Risk Transition to Production

Environmental and regulatory hurdles often delay gold projects, but Tunkillia's proximity to the fully permitted CGM mitigates these challenges. report, the DFS strategy exploits existing infrastructure to reduce capital intensity and accelerate timelines. Additionally, Barton Gold plans to submit a mining lease application for Tunkillia by year-end 2026, aligning with the completion of Phase 2 RC drilling (March–June 2026).

The company's Q3 2025 update highlights further progress: two-thirds of the Phase 1 drilling program was completed ahead of schedule, with assays from the S1 area expected to confirm the high-grade corridor's continuity. This transparency in drilling results-such as the 17 meters at 5.90 g/t Au from 79 meters-builds investor confidence in the project's technical integrity.

Investment Thesis: A Catalyst for Capital Appreciation

For investors, Tunkillia's value proposition hinges on its ability to convert inferred resources into bankable reserves while maintaining cost discipline. The A$1.4 billion NPV and A$800 million operating cash flow projections according to the update suggest a project capable of attracting project finance, particularly as gold prices remain elevated. Barton Gold's recent A$15 million capital raise, led by Franklin Templeton, and its inclusion in the S&P/ASX All Ordinaries Index further validate its transition from explorer to developer according to the update.

However, risks remain. The success of Phase 2 drilling and the DFS outcomes will determine whether Tunkillia's high-grade potential translates into a viable mine plan. Yet, given the project's current trajectory-under budget, ahead of schedule, and supported by robust metallurgical and geotechnical data-the balance of probabilities favors a positive outcome.

Conclusion

Barton Gold's Tunkillia S1 Pit exemplifies the ideal early-stage gold project: a high-grade, low-cost asset with clear de-risking milestones and a path to production. By prioritizing JORC resource upgrades, leveraging existing infrastructure, and maintaining operational transparency, the company has created a compelling investment case. For those willing to tolerate the inherent volatility of exploration-stage assets, Tunkillia offers a rare combination of geological promise and financial discipline-a catalyst worth watching in 2026.