QMines Pontoon Drilling Beats Resource Model by 20% With 2.07% Copper Hit

QMines Mt Chalmers pontoon drilling results show the first two holes beneath the flooded pit floor running about 20% above the 2024 resource model, with a 7.51% CuEq polymetallic lens at the top.
By William Hadrian -
  • The first two QMines Mt Chalmers pontoon holes ran roughly 20% above the 2024 Mineral Resource block model, the first modern-core test of ground beneath the pit lake.
  • Hole 26MCDD025 returned 16.7m at 1.04% Cu, 1.16g/t Au and 26g/t Ag, including 6.7m at 2.07% Cu, 2.37g/t Au and 60g/t Ag.
  • A 2.7m polymetallic lens at the top of 26MCDD025 grades 7.51% CuEq against a modelled 2.44%, and both holes began in mineralisation, so the zone remains open toward the pit floor.
  • Assays are pending for 37 more holes totalling 2,985m, with seven completed pontoon holes already at the laboratory and a third rig underway.
  • No new resource is reported and true widths are unknown, so continuity across the remaining holes will decide how much this feeds the next resource update and DFS.
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First pontoon assays return high-grade copper-gold-zinc beneath the Mt Chalmers pit floor

QMines Limited (ASX:QML) has received the first assay results from its in-pit pontoon diamond drilling program at the 100%-owned Mt Chalmers Copper-Gold Project. The results come from the first two holes returned from the laboratory, drilled from a rig mounted on a pontoon floating on the flooded pit.

Hole 26MCDD025 returned 16.7m at 1.04% Cu, 1.16g/t Au and 26g/t Ag from 23.3m, including 6.7m at 2.07% Cu, 2.37g/t Au and 60g/t Ag. Hole 26MCDD027, located 32m southeast, returned 11.3m at 1.32% Cu, 0.43g/t Au and 11g/t Ag from 42.7m.

Both holes ran approximately 20% above the 2024 Mineral Resource block model. That matters because since mining ended, the ground beneath the pit floor has sat under the pit lake, and the model has had to rely mainly on historical drilling. These are the first direct tests of that model with modern core.

All intercepts are downhole lengths, and true widths are not yet known. No new Mineral Resource or Ore Reserve estimate is reported.

Tom Bartschi, Exploration Manager, QMines

“These first two pontoon holes have delivered exactly what this program was designed to test, mineralisation directly beneath an area of the Mt Chalmers pit where modern drilling has previously been limited…”

Both holes beat the 2024 resource model

Copper equivalent (CuEq) is a single figure that converts the value of several metals into the equivalent amount of copper. It lets the drill results be compared directly with the resource model.

CuEq comparison

The table below sets the drill results against the model along each hole path. Both holes also exceeded the model blocks on either side of their traces.

Hole Interval Length Actual CuEq Model CuEq
26MCDD025 23.3m to 67.0m **43.7m** **1.31%** **1.10%**
26MCDD025 (including) 23.3m to 26.0m **2.7m** **7.51%** **2.44%**
26MCDD027 42.7m to 67.0m **24.3m** **0.99%** **0.84%**
26MCDD027 (including) 42.7m to 46.0m **3.3m** **3.50%** **1.67%**

The CuEq figures use the Mineral Resource formula, based on spot prices on 11 September 2026 and Pre-Feasibility Study (PFS) recoveries. Lead is not included.

Richest material sits at the top

The strongest grades sit immediately below the pit floor. The top 2.7m polymetallic lens in 26MCDD025 is about three times the grade of the model blocks it passes through, while the top 3.3m of 26MCDD027 is about twice the model.

Both holes start in mineralisation at the first core recovered, so the zone remains open up toward the pit floor. The depths of 23.3m and 42.7m must not be read as measured upper contacts.

Inside the polymetallic lens and copper zone

The top of 26MCDD025 holds a polymetallic lens of 2.7m at 5.25% Zn, 3.04% Pb, 4.44g/t Au, 109g/t Ag and 1.29% Cu from 23.3m. The first sample from the interval returned 174g/t Ag.

The lens sits directly above the highest-grade copper interval in the hole: 3.0m at 3.15% Cu, 1.15g/t Au and 31g/t Ag from 27.0m. The highest individual copper assay was 3.9% Cu from 28.0m to 29.0m.

Hole 26MCDD025 Vertical Zonation Profile

Other intercepts reported in the two holes include:

  • 26MCDD025: 5.0m at 0.57% Cu from 44.0m (copper-dominant)
  • 26MCDD025: 4.0m at 0.45% Cu from 52.0m (copper-dominant)
  • 26MCDD027: 8.3m at 1.64% Cu and 0.51g/t Au from 42.7m (copper-dominant, within the 11.3m interval)

Copper-dominant intervals use a 0.20% Cu lower cut-off, while polymetallic intervals use a 1.0% Zn lower cut-off. No top cuts were applied.

What is VHMS mineralisation, and why does it matter?

Mt Chalmers is a Kuroko-style volcanic-hosted massive sulphide (VHMS) system, hosted within the Permian volcanic sequence of the Berserker Graben. In plain terms, these deposits form from metal-bearing sulphide minerals laid down in volcanic rock.

In these systems, zinc, lead, silver and gold are commonly enriched toward the upper parts of the sulphide system. Copper-rich stringer and stockwork mineralisation typically occurs lower and closer to feeder zones.

The zinc-lead-gold-silver enrichment overlying copper-rich stringer mineralisation in 26MCDD025 is consistent with that vertical zonation. For you as an investor, it shows the new core behaving in line with the deposit type the project is understood to be.

What comes next for QMines

The pontoon program is the Company’s first drilling from inside the pit. The announcement points to several next steps:

  1. Assays are pending for a further 37 holes totalling 2,985m.
  2. A third drill rig is now underway.
  3. A further seven completed pontoon holes are at the laboratory.
  4. Every result will feed into the next Mineral Resource update, and the wider datasets will progressively inform the Mt Chalmers DFS.

For context, Mt Chalmers carries an Ore Reserve of 9.6Mt and a Mineral Resource of 11.3Mt, both from the 2024 PFS.

The Mt Chalmers DFS is being run in parallel with the drilling, with seven specialist firms engaged, so each new dataset from beneath the pit floor can feed engineering and design work as it arrives.

The pontoon holes also provide fresh core for geometallurgical testwork. No new metallurgical results are reported, and the company notes that assay grades alone do not establish metallurgical performance.

QMines says it has a substantial pipeline of results expected over the coming weeks, which should show whether the continuity and geometry of this mineralisation beneath the pit floor hold up across the remaining holes.

Ready to Discover More About the Mt Chalmers Copper-Gold Project?

QMines’ first pontoon assays have returned high-grade copper-gold-zinc beneath the Mt Chalmers pit floor, running about 20% above the 2024 Mineral Resource block model. With assays pending for a further 37 holes and the DFS progressing in parallel, the project has a substantial pipeline of results ahead.

Investors can explore the QMines Mt Chalmers project page to see the latest drilling results and the company’s development plans. Stay informed as each new dataset from beneath the pit floor is released.


Frequently Asked Questions

What is pontoon drilling at Mt Chalmers?

It is diamond drilling from a rig mounted on a pontoon floating on the flooded Mt Chalmers pit. QMines uses it to test mineralisation beneath the pit floor, where modern drilling has been limited.

What did the first QMines pontoon drilling results show?

Hole 26MCDD025 returned 16.7m at 1.04% Cu, 1.16g/t Au and 26g/t Ag, and hole 26MCDD027 returned 11.3m at 1.32% Cu, 0.43g/t Au and 11g/t Ag. Both ran roughly 20% above the 2024 Mineral Resource block model.

What is copper equivalent (CuEq) in drilling results?

Copper equivalent is a single figure that converts the value of several metals into the equivalent amount of copper. It lets drill results be compared directly with a resource model.

What is VHMS mineralisation?

Volcanic-hosted massive sulphide (VHMS) deposits form from metal-bearing sulphide minerals laid down in volcanic rock. Zinc, lead, silver and gold typically enrich the upper parts, with copper-rich stringer zones lower down.

What happens next after the QMines pontoon assays?

Assays are pending for a further 37 holes totalling 2,985m, including seven completed pontoon holes at the laboratory. The results will feed the next Mineral Resource update and the Mt Chalmers DFS.

William Hadrian
By William Hadrian
Partnerships Director
William supports Discovery Alert subscribers across Australia and overseas, helping them tailor alerts, troubleshoot technical issues, and optimise platform settings to suit their workflow.
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