QMines Ltd Deploys Floating Drill Rig Beneath Mt Chalmers Pit

QMines Deploys Floating Drill Rig Beneath Historic Pit in Bid to Access Copper-Gold Value

QMines (ASX:QML) has commenced diamond drilling beneath the historic Mt Chalmers open pit, using a purpose-built floating platform to reach mineralisation that has sat inaccessible under a flooded pit lake for decades. The Qmines Ltd floating drill rig beneath Mt Chalmers pit recovered its first drill core within a day of the programme commencing, according to the company's announcement.

The pontoon-based drilling forms part of a 10,000-metre campaign supporting the company's Definitive Feasibility Study (DFS) at its flagship Queensland copper-gold project. Management has flagged additional drilling at the Woods Shaft deposit as the next phase, describing the period ahead as one with a strong pipeline of catalysts.

"This is one of the most exciting drilling programs we've undertaken at Mt Chalmers because it has the potential to create value in two ways. Firstly, we're drilling beneath the existing pit where the deposit remains open at depth, providing an opportunity to grow the Mineral Resource. Secondly, we're upgrading confidence in existing mineralisation beneath the pit, creating the opportunity to convert additional resources into Ore Reserves that can support the Definitive Feasibility Study and potential for a larger or longer mine plan."
— Executive Chairman Andrew Sparke

Why Drilling Beneath a Flooded Pit Matters

The Mt Chalmers open pit has been flooded since mining ceased, and that body of water has prevented conventional land-based drill rigs from testing ground directly beneath the pit centre. Geologists have long interpreted the mineralised system as remaining open at depth, but validating that interpretation with modern drilling had not previously been possible.

To address the constraint, QMines engaged contractor United Drilling Services to design, mobilise and operate a floating drilling platform — a pontoon-mounted diamond drill rig capable of working from within the pit lake itself. This gives the company access to a zone that has never been systematically tested using modern diamond drilling techniques, according to the announcement.

The significance is tied to several factors:

• The deposit is interpreted as open along strike and at depth beneath existing mine workings.
• Previous drilling in this zone relied on older percussion drilling methods, which the company says can result in sample smearing within the drill hole and carry inherent limitations on sample quality.
• Much of the historic grade control drilling does not meet the quality assurance and quality control (QAQC) standards required under the current JORC Code, meaning this material remains classified as Inferred Resource and cannot be converted to Ore Reserves without modern validation.

A Dual-Purpose Programme Targeting Growth and Conversion

The Qmines Ltd floating drill rig beneath Mt Chalmers pit has been designed around two complementary objectives, according to the company.

Resource Growth Through Depth Extension Testing

The mineralised system at Mt Chalmers is interpreted to continue below the current pit floor. The programme represents the first systematic attempt to test that continuation using modern diamond core drilling. If successful, new mineralisation intersected at depth could contribute to an increase in the company's Mineral Resource estimate.

Reserve Conversion Through Inferred Material Upgrade

A portion of the existing Mineral Resource beneath the pit is currently classified as Inferred, partly because it was originally drilled using percussion methods that fall short of the confidence levels required under current JORC standards. By re-drilling this zone with diamond core and applying contemporary QAQC procedures, QMines aims to lift the confidence classification of this material and convert it into Ore Reserves capable of supporting the DFS and mine plan.

Understanding the Resource and Reserve Base

The scale of the drilling programme's potential impact is best understood against the project's existing resource and reserve position.

Mt Chalmers Ore Reserve

Mt Chalmers Mineral Resource

The 1.3 Mt of Inferred Resource at Mt Chalmers represents a direct conversion target — material that already sits within the deposit but requires modern drilling to be reclassified into a higher confidence category eligible for potential inclusion in the Ore Reserve.

Furthermore, QMines holds resources across three additional projects:

With Reserves of 9.6 Mt and combined Resources of approximately 20 Mt across the portfolio, QMines holds a resource base from which drilling programmes could contribute further growth.

Key Concept: What Is an Ore Reserve and Why Does It Matter?

What Is the Difference Between a Mineral Resource and an Ore Reserve?

A Mineral Resource is a geological estimate of mineralised material considered to have reasonable prospects for economic extraction. It is categorised by confidence level — Measured, Indicated, and Inferred — based on the density and quality of supporting drilling data.

An Ore Reserve, however, is a subset of a Mineral Resource assessed as economically mineable under stated conditions. It requires a higher level of data confidence, meaning Inferred Resources generally cannot be directly converted, and must be supported by detailed technical and economic studies.

Why Does This Matter for QMines?

The Ore Reserve underpins the DFS mine plan. A larger, higher-confidence Ore Reserve could support a larger or longer mine life, potentially strengthening the project economics the DFS is designed to establish. Converting Inferred material beneath the pit into Ore Reserves — one of the explicit aims of this programme — could support that case, according to management.

Quick Glossary

• DFS (Definitive Feasibility Study): A detailed technical and economic study assessing whether a project is viable for development.
• Diamond core drilling: A method that extracts a continuous cylindrical rock sample, providing higher-quality geological data than percussion methods.
• QAQC (Quality Assurance/Quality Control): Procedures ensuring the reliability of assay and sampling data.
• JORC Code: The Australasian standard for reporting mineral resources and reserves, setting the benchmark for data quality and disclosure.
• Percussion drilling: An older drilling method using repeated hammering action, faster and cheaper but generally less geologically precise than diamond drilling.
• Inferred Resource: The lowest confidence Mineral Resource category, which cannot be directly converted into Ore Reserves without further drilling.

What Comes Next in the Drilling Pipeline?

QMines has described the coming months as among its most active to date, with the Qmines Ltd floating drill rig beneath Mt Chalmers pit representing the opening stage of the broader 10,000-metre campaign.

Anticipated news flow includes assay results from the pontoon drilling, a commencement update and early results from the Woods Shaft programme, ongoing DFS progress as resource confidence develops, and a potential Mineral Resource update should drilling confirm extensions at depth.

The Investment Case: Multiple Workstreams Progressing in Parallel

QMines is at a stage where several activities are advancing simultaneously, each with the potential to independently affect project value. In addition to engineering progress, the company holds an identifiable resource conversion target with a defined pathway forward.

• Engineering progress: The DFS is underway, with drilling programmes designed to feed directly into its resource and reserve inputs.
• Resource conversion potential: The Inferred material beneath the Mt Chalmers pit represents an identifiable target with a defined pathway toward Ore Reserve status.
• Resource growth potential: The deposit remains open at depth, and this marks the first time it has been drilled with modern techniques, meaning the extent of any upside is not yet known.
• Portfolio depth: Combined resources of approximately 20 Mt across four projects — Mt Chalmers, Develin Creek, Woods Shaft, and Mt Mackenzie — provide optionality beyond the core mine plan.
• Technical execution: The design and deployment of a floating drill platform demonstrates a capacity to apply engineering solutions to access previously untestable ground.

Mt Chalmers carries considerable historical significance, having produced 1.2 Mt at 2.0% Cu, 3.6 g/t Au, and 19 g/t Ag between 1898 and 1982. The current resource estimate of 0.75% Cu and 0.42 g/t Au across 11.3 Mt represents a modern resource built around the same mineralised system.

Why Investors May Want to Watch QMines Closely

The commencement of pontoon drilling beneath Mt Chalmers marks the activation of a drilling capability at a deposit that has had a physical barrier to exploration for decades. The stated dual objective — growing resources while converting Inferred material to Ore Reserves — ties directly into the DFS process and the company's development pathway.

Consequently, with the Woods Shaft programme set to commence at a similar time, QMines will have multiple drilling operations running concurrently, each targeting outcomes that could affect the scale and economics of the broader project.

Key Takeaway
The Qmines Ltd floating drill rig beneath Mt Chalmers pit has been deployed to test ground that has been inaccessible for decades. The programme's dual objective — growing the Mineral Resource and converting Inferred material into Ore Reserves — is designed to feed directly into the DFS. Combined with the upcoming Woods Shaft drilling campaign and a combined resource base of approximately 20 Mt across the portfolio, the coming months present several catalysts for those following the company's copper-gold project.

Ready to Dig Deeper Into QMines' Copper-Gold Project?

QMines (ASX:QML) is advancing one of Australia's most compelling copper-gold development stories, with multiple drilling programmes now running concurrently and a clear pathway toward a Definitive Feasibility Study. From the pioneering pontoon drilling beneath Mt Chalmers' flooded pit to the imminent launch of the company's largest-ever Woods Shaft programme, the coming months are shaping up as a pivotal period for the company. With a combined resource base of approximately 20 Mt across four projects and identifiable conversion targets already in the ground, investors seeking exposure to a project with near-term catalysts may want to take a closer look. Visit the QMines investor page to learn more about the Mt Chalmers copper-gold opportunity.