Aurelia Metals Posts 49% Reserve Jump After Depletion as Peak Copper-Gold Base Grows
Key Takeaways
- Aurelia Metals' Group Ore Reserve grew 49% after depletion to 8.2Mt, meaning the company replaced everything it mined and added significantly more — a net inventory gain, not a holding pattern.
- Peak underground reserve increased 22% after depletion to approximately 4.1Mt, with the Production Target rising 25% to 6.4Mt at an average NSR of A$310/t, up from A$270/t in 2025.
- Federation's grade sharpened to 14.7% Pb+Zn (from 12.1%), with Measured category resource jumping from 2% to 16% of total — a deliberate shift to higher-margin ore, not a resource contraction.
- A maiden New Occidental Tailings Ore Reserve of 2.3Mt at 0.64g/t Au adds low-capital gold production through existing Peak plant infrastructure, with retreatment targeted to commence FY28.
- Gold price leverage is built into the reserve base at US$2,400/oz — below the current spot assumption of US$2,600/oz used for Mineral Resources — providing a buffer against price volatility while still supporting the economic case.
Aurelia Metals Lifts Group Ore Reserve 49% as Peak Copper-Gold Base Strengthens
Aurelia Metals announced a significant expansion of its Cobar Basin resource inventory on 27 August 2026, with Group Ore Reserve increasing 49% after depletion to 8.2Mt. The updated estimate reflects 5.9Mt of underground reserves and 2.3Mt from the maiden New Occidental Tailings reserve, positioning the company’s three underground mines across two operations for extended production.
Group Mineral Resource rose 6% after depletion to 30.6Mt (from 29Mt in 2025), comprising 28Mt underground and 2.6Mt tailings. The update was supported by independent audit from Mining One, which identified no fatal flaws in the methodology or assumptions.
Interim CEO Martin Cummings positioned the results as “the foundation for a long-life operation in the Cobar Basin,” with Peak remaining the cornerstone copper-gold asset and Federation evolving into a high-grade zinc-lead-gold source.
| Metric | 2025 | 2026 | Change | Note |
|---|---|---|---|---|
| Group Ore Reserve | 5.5Mt | 8.2Mt | +49% | after depletion |
| Peak Underground Reserve | ~3.3Mt | ~4.1Mt | +22% | after depletion |
| Peak Production Target | 5.1Mt | 6.4Mt | +25% | avg NSR A$310/t |
| Group Production Target | 8.6Mt | 9.2Mt (u/g) | +7% | avg NSR A$330/t |
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Peak Cements Its Role as the Copper-Gold Cornerstone
Peak underground Ore Reserve increased 22% after depletion to approximately 4.1Mt, driven by drilling at the Kairos copper lens, Peak North and Chesney lower levels, plus updated economics showing strong leverage to gold price. The Mineral Resource grew to 21.4Mt, including 19.6Mt of copper mineralisation grading 1.8% Cu and 0.8g/t Au.
Peak Ore Reserves now carry a strong 1.8g/t Au gold grade, adding precious-metal leverage to the primary base metal value. Peak Production Target increased 25% to approximately 6.4Mt with average net smelter return (NSR) rising to A$310/t (from A$270/t in 2025).
The Peak Resource is anchored by the copper-gold system but retains optionality for expansion. The Great Cobar project—approved in April 2025—sits within the Peak operation footprint and will unlock further growth once underground drill platforms are established. Great Cobar’s infrastructure requirements, as documented in the Feasibility Study, include twin decline access, fresh air rise, primary surface fan upgrade, underground batching plant and dewatering of the Great Cobar historical workings.
The net smelter return (NSR) cut-off used to define economic reserves reflects the full cost chain: stoping, haulage, processing, freight, treatment charges, penalties and royalties. For Peak, stoping NSR cut-offs range from A$195/t to A$205/t depending on deposit complexity. Development material requires a minimum A$50/t NSR. These cut-offs are derived from Peak’s life-of-mine cash flow model and reflect steady-state operating costs.
Martin Cummings, Interim Chief Executive Officer
“Peak remains the cornerstone of our business, underpinned by a growing copper and gold Resource base, while Federation continues to evolve as a high-grade ore source, providing operational flexibility and growth opportunities.”
Federation Sharpens Into a Higher-Grade Base Metal Source
Federation’s updated Mineral Resource tells the story of tighter definition, not contraction. Infill drilling drove the Resource grade to 14.7% Pb+Zn (from 12.1% in 2025), with a much higher proportion now in the Measured category (16%, up from 2%). Mineral Resource tonnage decreased 27% to 3.2Mt, and Ore Reserve decreased 18% to 1.8Mt, reflecting depletion, higher cut-off values and tighter domain boundaries.
Production Target decreased 20% to 2.8Mt but at a significantly higher average NSR of A$360/t (up from A$300/t). What appears as a tonnage reduction is in fact a deliberate shift to a higher-grade, higher-margin orebody as infill drilling defines economic mineralisation more precisely.
An exploration decline is planned for excavation during FY27. This decline will provide platforms for extensional drilling, targeting zones below and along strike of the currently defined Resource. Federation’s role within Aurelia’s portfolio is evolving from a tonnage contributor to a high-grade, flexible ore source that can be blended with Peak feed to optimise metallurgical outcomes.
The Federation underground Ore Reserve supports stoping methods including uphole and downhole longhole stoping with cemented rockfill and unconsolidated fill. Stope shapes allow for up to 0.45m hangingwall and footwall dilution, with a minimum mining width of 3m. Additional dilution and recovery factors are applied based on ground conditions, with stopes in shear zones attracting higher dilution assumptions (10% for downhole stopes, 10% for uphole stopes, 20% for sill pillars).
What Mineral Resources and Ore Reserves Actually Mean
Mineral Resources and Ore Reserves operate within a JORC-defined hierarchy. A Mineral Resource is the portion of mineralisation in the ground that has reasonable economic prospects, categorised by geological confidence: Measured (highest), Indicated (moderate), Inferred (lowest). An Ore Reserve is the economically mineable portion of a Mineral Resource after applying mining, dilution and cost factors. Ore Reserves are classified as Proved (derived from Measured) or Probable (derived from Indicated).
The term “after depletion” refers to reserves that have grown even after accounting for ore extracted during the year. It is a net gain—a genuine increase in the company’s inventory of economically mineable material—and signals mine-life extension rather than depletion of the asset.
Net Smelter Return (NSR) is the net dollar value per tonne after processing, freight, treatment charges, penalties and royalties. NSR cut-offs are used to decide what material is economic to mine. Aurelia uses a A$145/t NSR for Mineral Resources across the Cobar region, reflecting break-even mining and milling costs. Ore Reserve cut-offs are higher and reflect additional operational constraints.
For you as an investor, the key insight is this: reserves grew after depletion, and the average NSR across the Group increased. That tells you the company is replenishing what it mines with higher-quality inventory, which reduces the risk of production shortfalls and supports reinvestment into future growth.
New Occidental Tailings Adds Low-Cost Incremental Production
Aurelia reported a maiden Group Tailings Stockpile Ore Reserve of 2.3Mt at 0.64g/t Au (Mineral Resource 2.6Mt at 0.65g/t Au). The New Occidental Tailings are legacy material from historic processing, reprocessed in the late 1980s and deposited into two dry-stacked surface facilities.
The metallurgical attraction is straightforward: free-dig surface material, processed through the existing Peak plant in parallel with fresh ore feed. Capital cost is low—a wet-trommel circuit, dewatering cyclone and trash screen, plus sheeting of the existing haul road. Operating cost is marginal. The Feasibility Study is progressing through H1 FY27, with retreatment planned to commence FY28.
Peak processing capacity will increase to 1.1–1.2Mtpa once the Tertiary Ball Mill is commissioned in early FY27. The New Occidental Tailings feed can be added without displacing underground ore throughput, effectively extending mill utilisation and recovering gold that was left in the tailings during the original processing campaign.
Metallurgical recovery assumptions for the New Occidental Tailings are based on a combination of onsite testwork (December 2023), a bulk sample campaign (November 2023 to October 2024), and offsite testwork (April 2025). Ausenco reviewed all data and recommended a recovery of 63.3% for project evaluation. Aurelia used 60% in the Pre-Feasibility Study financial modelling, providing a conservative margin.
The following table summarises the regional Mineral Resource position outside the main Peak and Federation operations:
| Project | Ownership | Tonnage (Mt) | Grade |
|---|---|---|---|
| Nymagee | 95% | 2.8 | 2.0% Cu |
| Queen Bee | 100% | 0.6 | 2.5% Cu |
Both Nymagee and Queen Bee saw Mineral Resource tonnage decreases in 2026, driven by an increase in the NSR cut-off value and updated economic parameters. For Queen Bee, the cut-off increased from A$130/t to A$145/t. The result is a smaller tonnage but higher average copper grade, as marginal material dropped out of the reportable inventory.
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The Investment Case and What Comes Next
Aurelia now reports producing operations, 49% reserve growth after depletion, organic growth projects (Great Cobar, Federation extensions, New Occidental Tailings), and a prospective exploration portfolio across the Cobar Basin. The updated Mineral Resource and Ore Reserve Statement positions the company to extend mine life and convert strategic inventory into profitable production.
The updated estimates reflect strong leverage to gold price. Peak’s Production Target carries an average NSR of A$310/t, up from A$270/t, driven primarily by higher gold prices and improved metallurgical recoveries. The gold price assumption for Ore Reserves is US$2,400/oz (A$3,429/oz at 0.70 exchange rate), below the Mineral Resource price assumption of US$2,600/oz, providing a buffer for price volatility.
Key forward milestones include:
- FY27: Federation exploration decline excavation; New Occidental Tailings Feasibility Study (H1); Tertiary Ball Mill commissioning
- FY28: New Occidental Tailings retreatment commences
- Ongoing: Great Cobar underground drill platforms to unlock expansion
Cummings framed the update within the context of long-term value creation: converting the strategic Resource base into “profitable production and growing returns for shareholders.” The updated inventory supports that thesis. The company has replaced what it mined, at higher average grade and higher average NSR, and added a low-cost gold project that leverages existing infrastructure.
The Production Target includes 19% Inferred material by tonnage. The JORC Code requires disclosure that Inferred Mineral Resources carry lower geological confidence, and there is no certainty they will convert to Indicated or that the Production Target will be realised. However, the Inferred portion is not the determining factor in project viability—the Ore Reserve (derived from Measured and Indicated Resources) represents 70% of the Group Production Target tonnage and underpins the economic case.
For you as an investor, the question is whether the company can execute on the organic growth pipeline while maintaining production discipline. The updated resource statement provides the inventory to support that execution. The next test is delivery.
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