Maritana Minerals Declares Maiden 31,600 Oz Ore Reserve at Rose Hill Underground

Maiden Ore Reserve Advances Rose Hill Towards Production

Maritana Minerals Limited (ASX:MRT) has taken a significant step forward at its Rose Hill Project near Coolgardie, Western Australia, by declaring a maiden underground Ore Reserve of 420,000 tonnes grading 2.34 grams per tonne gold, equating to 31,600 ounces. This milestone pushes Maritana’s total Ore Reserves inventory to 235,600 ounces, marking a meaningful advance in the company’s gold portfolio.

Managing Director Grant Haywood highlighted the importance of this reserve declaration, noting that it confirms Rose Hill’s economic viability and moves the project closer to development. The updated underground Mineral Resource stands at 524,000 tonnes at 4.49 g/t Au for 76,000 ounces, reported at a lowered 1.0 g/t cut-off grade, reflecting a stronger gold price and optimisation outcomes. An additional inferred resource of 194,000 tonnes at 4.53 g/t Au, containing 28,000 ounces, remains outside the Ore Reserve and offers upside potential with further drilling.

Mining Method and Economic Assessment

The pre-feasibility study underpinning the Ore Reserve was completed by Mining Plus in July 2026. It endorses long hole open stoping with pillars as the preferred underground mining method, chosen for its suitability to the steeply dipping orebody and operational efficiencies. The cut-off grade for the underground Ore Reserve was set at 1.3 g/t Au, balancing operating costs with expected revenue at a gold price assumption of AUD 4,500 per ounce.

Mining Plus’ detailed mine design incorporates a top-down extraction sequence with permanent rib pillars, aiming for a mine life of approximately 26 months and a production rate of around 270,000 tonnes per annum. The study includes comprehensive geotechnical assessments by Absolute Geotechnics, which informed stope sizes and pillar dimensions to maintain ground stability.

Economic modelling indicates positive free cash flow at the assumed gold price, with the Measured and Indicated inventory alone generating an estimated A$24.5 million. Including inferred material, which is excluded from reserves due to geological uncertainty, the project’s free cash flow projection rises to over A$54 million. Sensitivity analyses confirm that production rates and recovery assumptions materially impact cash flow outcomes.

Processing and Infrastructure Leverage

Rose Hill ore will be trucked approximately 85 kilometres to Maritana’s Black Swan Processing Hub near Kalgoorlie, where works are underway to convert the plant for gold processing. The Black Swan facility is planned to operate initially at 1.5 million tonnes per annum throughput, with capacity for up to 2.2 million tonnes. This hub-and-spoke approach leverages existing infrastructure, reducing capital intensity and expediting project timelines.

The company has also progressed key approvals and infrastructure at Black Swan, including power and water upgrades, and workforce accommodation solutions, aligning with expectations for first gold production in the second half of 2027. This integrated development strategy positions Maritana to efficiently bring Rose Hill underground production into the company’s broader gold portfolio.

Resource and Reserve Classification

The Mineral Resource and Ore Reserve estimates comply with the JORC Code (2012 edition), with Measured and Indicated Resources converted to Proved and Probable Reserves respectively. The underground Mineral Resource extends to approximately 400 metres below surface, with the open pit resource constrained to about 50 metres depth. The Ore Reserve excludes inferred material, reflecting standard industry caution given the speculative nature of such resources.

Maritana’s resource modelling employed Dynamic Anisotropic Ordinary Kriging within detailed geological domains, supported by extensive drilling data comprising over 22,000 metres from 284 holes. Quality assurance protocols and site visits by competent persons underpin confidence in the data integrity and resource estimation.

What Lies Ahead for Maritana Minerals

With the maiden underground Ore Reserve now declared, the focus shifts to advancing feasibility studies, securing full approvals, and continuing drilling to convert inferred resources at depth. Monitoring progress on the Black Swan Processing Hub upgrade will be critical, as the timing and success of the plant conversion directly influence production schedules.

Gold price volatility remains a key variable affecting the project’s economics, alongside mining recovery and capital development costs. How Maritana navigates these factors will shape Rose Hill’s trajectory from resource to revenue.