Qmines Ltd (ASX:QML) Develin Creek Resource Upgrade Paves Way for Expansion Plans

23 February 2026

Price Sensitive Announcement $

Highlights:

Key Highlights

• Indicated Resources Jump 46% to 4.22Mt at 0.98% copper and 1.08% zinc
• Total Mineral Resource increases 14% to 4.70Mt at 0.94% copper and ~1.0% zinc
• 90% Indicated classification – a major leap in geological confidence following infill drilling
• Mineralisation remains open along strike and at depth, with upside still evident
• Supports advancement of optimisation studies and integration into the Mt Chalmers development pathway
• Builds on QMines’ consistent track record of resource growth (this marks another upgrade in the series)

Overview:

QMines Limited has reported an upgraded Mineral Resource Estimate (MRE) for the Develin Creek Copper–Zinc–Gold–Silver Project, located approximately 90 km northwest of Rockhampton, Queensland. The updated MRE has been completed by Hyland Geological and Mining Consultants (HGMC) in accordance with the JORC Code (2012) and ASX Listing Rule 5.8.1.

The upgrade reflects a significant increase in Indicated Mineral Resources, supported by the 2024– 2025 infill and extension drilling programs. It also incorporates a revised geological interpretation that better defines the stacked and locally discontinuous volcanogenic hosted massive sulphide (VHMS) lens geometry.

Updated Mineral Resource Estimate

The Mineral Resource Estimate (MRE) is reported on an individual metal basis using Cu % as the primary reporting variable at a nominal 0.30% Cu cut off. Copper equivalent is not used as the primary reporting basis for the current estimate. The 0.30% Cu cut-off grade represents a reporting threshold informed by preliminary metallurgical testwork and conceptual assumptions considered reasonable for VHMS-style deposits in the region. No Ore Reserves have been reported.

Infill drilling improved geological confidence and continuity, resulting in a 14% increase in total Mineral Resource tonnes, with a modest reduction in average copper grade.

Resource Upgrade Improves Confidence

This upgrade materially improves the confidence profile of the Develin Creek Mineral Resource and strengthens the technical platform for the next stage of evaluation. The principal change is the reclassification of a substantial proportion of previously Inferred material into the Indicated category.

This reclassification is supported by increased drill density, refined geological interpretation consistent with VHMS-style lens geometry, and improved estimation confidence measures.

Improved Continuity Control

The expanded Indicated classification is supported in areas where drill spacing is typically in the order of ~20m × 20m to 25m × 25m, providing a materially stronger spatial control on lens position, thickness variability, and grade distribution. In these zones, the informing data distribution supports tighter grade interpolation with reduced reliance on extrapolation, evidenced by:

• improved sample support within the defined search neighbourhoods, including sufficient informing composites and acceptable composite counts per estimate.
• lower kriging variance and improved local estimation confidence relative to the previously broader, more sparsely informed volumes.
• a more constrained and geologically realistic wireframe interpretation that reflects stacked, discontinuous sulphide lenses rather than assuming tabular continuity beyond data support.
• Collectively, these factors reduce uncertainty in short range continuity, which is the primary driver of classification uplift under JORC (2012) for VHMS lens systems.

Implications for Technical Evaluation

The upgraded confidence distribution materially improves the suitability of the resource model for earlystage evaluation work. An Indicated dominant resource base improves the reliability of:

• volumetric continuity and local thickness assumptions used in stope or open pit design concepting (depending on mining method options assessed).
• grade distribution assumptions underpinning preliminary mining selectivity, dilution and loss sensitivity analysis.
• development sequencing scenarios, where scheduling decisions are sensitive to local continuity and grade variability.

Remaining Inferred zones are interpreted to reflect either data spacing limitations, boundary uncertainty at the lens margins, or areas where local continuity is less well constrained. These areas represent clear targets for follow up drilling focused on reducing boundary uncertainty (lens edges), tightening grade continuity at depth or along plunge where applicable and confirming thickness variability in structurally modified portions of the system.

Development Readiness Uplift

QMines announced the development strategy for its flagship Mt Chalmers Project in January 20261, and announce the initiation of the Definitive Feasibility study (DFS) on 10 February2 . The Company intends to progress the 1Mtpa Mt Chalmers case and complete a scoping level expansion case which will assess the viability of processing Develin Creek mineralisation through the proposed Mt Chalmers Mill to grow throughput or extend mine life.

The high proportion of Indicated Mineral Resources strongly supports robust design and scheduling decisions once appropriate modifying factor work is completed. In practical terms, the confidence uplift achieved in the February 2026 update improves the technical basis for:

• progressing mine planning options and staging logic with reduced classification driven risk.
• defining targeted drilling programs that are conversion focused rather than broad reconnaissance, allowing higher efficiency deployment of metres.
• prioritising metallurgical and geotechnical testwork to match the improved spatial confidence in the mineralised envelopes, including representative composites and variability coverage aligned to the upgraded domains.
• refining process assumptions, recovery drivers and concentrate quality considerations in a way that is better grounded to the higher confidence volumes.

Overall, the improved classification profile enhances the foundation for the next phase of technical studies, including infill drilling, metallurgical optimisation and engineering definition work

Oxide And Fresh Material Breakdown

The February 2026 Mineral Resource Estimate has been sub-divided by oxidation state into Oxide and Fresh material domains. At a 0.30% Cu cut-off, the resource is dominated by fresh sulphide material, which accounts for approximately 91% of total tonnes. Oxide material represents the remaining ~9% and is predominantly classified as Indicated.

Develin Creek Mineral Resource Estimate – Oxide vs Fresh Breakdown (January 2026, 0.30% Cu cut-off):

Fresh sulphide material totals 4.27 Mt (91% of total tonnes), comprising 3.80 Mt Indicated at 0.99% Cu and 1.13% Zn, and 0.47 Mt Inferred at 0.61% Cu.

Oxide material totals 0.43 Mt (9% of total tonnes), comprising 0.42 Mt Indicated at 0.88% Cu and 0.59% Zn, with a minor Inferred component of approximately 0.01 Mt.

The predominance of fresh sulphide material is consistent with the VHMS deposit style at Develin Creek and is favourable for conventional flotation processing, with the oxide component representing a relatively modest proportion of the total inventory. Oxide material grades are lower across zinc, gold and silver relative to the fresh material, reflecting the mobility of these metals during weathering.

Company Notes:

Executive Chairman, Andrew Sparke, comments:
“This updated Develin Creek Mineral Resource marks an important step forward for QMines, with the deposit now reaching the scale and confidence required to progress into Phase 2 mine planning studies. With approximately 90% of the resource now classified in the Indicated category, the project has moved quickly from exploration towards development readiness, providing a strong foundation for future mine planning.

Importantly, the mineralisation remains open along strike and at depth, highlighting the strong potential for further resource growth through targeted exploration. As confidence in the geological model continues to build, the Company intends to commence underground optimisation studies to assess the deeper parts of the mineralized system and support detailed mine planning. Together, these next steps position Develin Creek as a key future production source within the broader Mt Chalmers hub strategy, with additional upside subject to further exploration and technical studies.”

Full ASX Announcement: QMines Ltd ASX Announcement