Tolu Minerals Doubles Gold Resources to 1.33Moz as New Deposit Adds Second Growth Engine
Key Takeaways
- Tolu Minerals' total reported gold Mineral Resources have more than doubled to 1.33 Moz in September 2026 alone, rising 111% from 631,000 oz at the start of the month.
- The maiden Mt Penck Mineral Resource Estimate of 293,000 oz (7.3 Mt at 1.2 g/t Au) is constrained to the upper 200 m and is open in every direction, meaning the current estimate is a floor, not a ceiling.
- Beneath the gold cap sits the Kavola Porphyry — a copper-gold target approximately 1.6 km by 900 m in interpreted extent with chargeability persisting to at least 400 m depth — virtually untested by drilling.
- Rio Tinto has applied for an exploration licence adjoining Mt Penck to the south-west, adding independent weight to the corridor's prospectivity.
- Tolukuma remains the near-term production priority with seven rigs drilling a 75,000 m campaign and a return to gold production planned for early 2027, while the Board evaluates a separate funding vehicle for Mt Penck to advance both projects simultaneously.
Gold resources more than double to 1.33 Moz in a single month
September 2026 has delivered a milestone that reshapes how the market should think about Tolu Minerals (ASX: TOK). The company’s reported gold Mineral Resources have more than doubled this month to 1.33 Moz, up 111% from the 631,000 oz reported at the start of September.
Two events drove this result. The 81% uplift at Tolukuma, announced on 16 September 2026 and taking that deposit to 909,000 oz, combined with a maiden Mineral Resource Estimate (MRE) of 293,000 oz at the Mt Penck Gold-Copper Project, announced herein.
The portfolio now spans three deposits: Tolukuma (909,000 oz), Saki (128,000 oz), and Mt Penck (293,000 oz). Critically, this is not simply resource growth at a single asset. Mt Penck is emerging as a second, stand-alone project that operates independently of the Tolukuma restart.
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Portfolio snapshot: three deposits, 1.33 Moz
The full resource picture across the three deposits is set out below. Note that the estimates carry different effective dates, deposit styles, and cut-off grades, and their grades have not been aggregated.
| Project | Category | Tonnes (Mt) | Au (g/t) | Au (koz) | Cut-off |
|---|---|---|---|---|---|
| Tolukuma | Indicated | 0.85 | 7.33 | 199 | 3.0 g/t Au |
| Tolukuma | Inferred | 3.46 | 6.38 | 710 | 3.0 g/t Au |
| Saki | Inferred (previously reported) | 2.0 | 2.0 | 128 | 1.0 g/t Au |
| Mt Penck | Inferred | 7.3 | 1.2 | 293 | 0.5 g/t Au |
| Total | — | 13.6 | Not aggregated | 1,330 | — |
Source: Tolu Minerals reported gold Mineral Resources, September 2026. Minor rounding differences may occur.
Dr Chris Muller, Managing Director and CEO, Tolu Minerals
“At the start of this month Tolu’s reported gold resources stood at 631,000 ounces. Today that number is 1.33 million ounces. The Tolukuma upgrade did most of the work and remains our focus: the restart is fully permitted, seven rigs are drilling and we intend to be in production early next year.
Mt Penck is a different kind of opportunity and deserves to be understood on its own terms. It starts with 293,000 ounces of shallow gold that is open in every direction and will be the first target of our drills. But what makes it compelling is what sits beneath and beside that gold cap…”
Mt Penck: a coastal project with two prizes
The maiden MRE for Mt Penck totals 293,000 oz (7.3 Mt at 1.2 g/t Au), reported at a 0.5 g/t Au cut-off and classified entirely as Inferred under the JORC Code (2012). The estimate was prepared independently by Steve Rose of Rose Mining Geology Consultants, with an effective date of 20 September 2026.
The resource is constrained to the upper 200 m of the deposit and is open down dip and along strike. Almost all historical drilling stopped above that depth, meaning the current MRE represents a floor, not a ceiling.
Logistics are a genuine competitive advantage here. Mt Penck sits approximately 55 km west of Kimbe and its deep-water port, reachable by sea to an existing wharf at Silavuti, which is around 4.5 km from the licence. Drill rigs and heavy equipment can be landed by barge directly adjacent to the project area, a logistical position that is rarely available to gold-copper projects in Papua New Guinea.
The porphyry beneath the gold cap
The Mt Penck system offers two distinct layers of opportunity. The 293,000 oz gold MRE occupies the upper 200 m as a high-sulphidation epithermal cap. A high-sulphidation epithermal deposit is a style of gold mineralisation that forms near the surface, typically above a larger intrusive system. Beneath and beside that cap lies the Kavola Porphyry, a copper-gold porphyry target approximately 1.6 km by 900 m in interpreted extent, with a chargeability halo persisting to at least 400 m depth.
The target is virtually untested by drilling. Only two historical holes went below 300 m, and the one hole that reached the halo, MPD075, carried sulphides over its full 400 m length. The Independent Geologist’s Report describes the evidence for this porphyry system as “compelling.”
The Independent Geologist’s Report (Douglas Hutchison, effective 20 August 2026) classifies Mt Penck as an Advanced Exploration Project under the VALMIN Code. Mt Penck sits on the Kulu-Simi Corridor, which hosts the Simuku and Mt Nakru copper-gold deposits, referenced here for geological context only and not necessarily indicative of mineralisation at Mt Penck. Adding external weight to the corridor’s prospectivity, Rio Tinto has applied for an exploration licence adjoining Mt Penck to the south-west.
Planned drill program
Four priority targets have been identified for the first phase of drilling:
- Kavola Shallow — infill and step-out epithermal gold-silver target within the existing resource footprint
- Peni Creek — 400 m west of Kavola; Tolu’s 2023 trenching returned 4 m at 5.57 g/t Au including 1 m at 18.2 g/t Au (PCTR07)
- Kavola East — deep porphyry copper-gold target, diamond holes of 500 m to 1,000 m; undrilled
- Kavola Northeast — deep porphyry copper-gold target, diamond holes of 500 m to 1,000 m; undrilled
The Independent Geologist has reviewed a proposed two-year work program and budget of approximately A$30 million, comprising around 40,000 m of drilling using three company-operated rigs, together with mapping, sampling, LiDAR and ground geophysics, and considers the program and budget warranted and appropriate.
Beyond the MRE, the Competent Person has also estimated an Exploration Target for Mt Penck (exclusive of the Mineral Resource) as set out below.
| Domain | Range | Tonnes (Mt) | Grade |
|---|---|---|---|
| Gold | Low | 13.2 | 0.7 g/t Au |
| Gold | High | 33.0 | 1.2 g/t Au |
| Copper | Low | 17.6 | 0.2% Cu |
| Copper | High | 44.0 | 0.5% Cu |
Source: Mt Penck Exploration Target ranges for the gold and copper domains (RMG, 2026), exclusive of the Mineral Resource. The gold and copper domain targets are independent of each other with no double counting between them.
Cautionary statement: The potential quantity and grade of the Exploration Target is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a Mineral Resource.
What is a high-sulphidation epithermal system, and why does the porphyry matter?
High-sulphidation epithermal deposits form near the surface, directly above large intrusive systems known as porphyries. The shallow gold cap is typically the easier component to find and mine; the porphyry below is generally much larger in tonnage and can carry significant copper alongside gold.
At Mt Penck, that structure is clearly visible: 293,000 oz of shallow gold sits within the upper 200 m, with geophysics now revealing a 1.6 km by 900 m porphyry target at depth that has barely been tested by drilling. The Inferred classification of the MRE reflects historical drill spacing and data quality — Tolu has not yet drilled at Mt Penck itself — and the planned drilling program is specifically designed to upgrade confidence and grow the resource from this starting point.
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Tolukuma remains priority one, and Mt Penck gets its own funding lane
Tolukuma is the company’s immediate focus. A 75,000 m near-mine drilling campaign is underway with seven rigs, a detailed exploration update is expected in October 2026, and a return to gold production is planned for early 2027 from existing, fully permitted infrastructure.
The resource growth at Tolukuma builds on a series of structural discoveries made earlier this year, including the identification of new high-grade gold vein systems at Tolukuma that extended the known mineralised corridor and provided the geological foundation for the current 75,000 m drill campaign.
For Mt Penck, the Board is evaluating options to capitalise the project separately, including the potential for a dedicated vehicle with its own funding and technical team. Any such structure would be designed so that Tolu shareholders retain substantial exposure to the project’s upside. No decision has been made, and any transaction would be subject to Board approval, regulatory and shareholder requirements as applicable, and market conditions.
Dr Chris Muller, Managing Director and CEO, Tolu Minerals
“Mt Penck deserves its own funding and its own team so it can move at pace without competing with the mine for capital, and the Board is assessing how best to achieve that while keeping the upside with Tolu shareholders.”
The near-term catalyst pipeline for both projects is as follows:
- October 2026: Detailed Tolukuma drilling update expected
- Early 2027: Planned return to gold production at Tolukuma
- TBD: Mt Penck funding structure announcement
- TBD: Phase-one drilling program commencement at Mt Penck
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