Mt Malcolm Mines Advances Calypso Gold Prospect Drilling Near Leonora

Mt Malcolm Mines Advances Drill Program at Calypso Gold Prospect — A Potential Game-Changer in the Yilgarn Craton

Mt Malcolm Mines NL (ASX: M2M) has announced it is advancing plans for a drilling program at its Calypso Gold Prospect, located approximately 25 km southeast of Leonora, Western Australia. The program is designed to convert a historical Exploration Target of 2.9–3.9 Mt at 1.6–2.2 g/t Au for 153,000–279,000 oz Au (assessed by independent consultants BMGS in 2019) into a Maiden JORC 2012 Mineral Resource, while also testing high-grade extensions discovered by M2M's own 2022–2023 diamond drilling campaign.

The announcement is significant for several reasons. Calypso sits within one of Australia's most celebrated gold-producing corridors — the Norseman–Wiluna Greenstone Belt of the Yilgarn Craton. It has attracted more than 20,000 m of cumulative historical drilling from major operators including BHP and North Ltd.

M2M's own recent drilling confirmed a new high-grade discovery zone — the Constance Lodes at T3 — with standout intercepts including 16.21 m at 4.01 g/t Au from 343.25 m depth, and mineralisation that remains open down plunge.

Critically, this program is not starting from scratch. Pre-drilling activities — including contractor tendering, geological model updates, drill planning, and regulatory submissions — are advancing in parallel with a capital raise, allowing the company to mobilise rapidly upon funding close.

Key Highlights at a Glance

The Exploration Target is not a Mineral Resource and has not been classified under JORC 2012. It is conceptual in nature and cited for historical reference only. There has been insufficient exploration to define a Mineral Resource, and it is uncertain whether further exploration will result in one being defined.

A Geologically Compelling Address in Australia's Premier Gold Belt

Calypso is not just another exploration prospect. Its location within the Norseman–Wiluna Greenstone Belt of the Yilgarn Craton places it in the same geological corridor that hosts some of Australia's most celebrated gold deposits — including Wallaby, Granny Smith, and Gwalia. While the scale of those deposits is not implied for Calypso, the geological pedigree of the belt provides meaningful context for the style of mineralisation being targeted.

The gold mineralisation at Calypso is hosted within magnetite-rich siltstone units, characterised by iron-carbonate–pyrite–quartz alteration — a signature consistent with orogenic gold systems. The mineralised sequence forms a macroscopic overturned syncline, with the western limb dipping at 40°–60° northwest.

This predictable structural geometry is a meaningful advantage. It enables confident targeting of down-plunge extensions and improves the probability of intersecting further mineralised lodes with systematic drilling.

In 2021, M2M completed a high-resolution ground gravity survey that, when integrated with historical magnetic data, defined four blind, high-priority geophysical targets (T1–T4). These gravity anomalies have no surface expression, meaning the gold-bearing structures are concealed at depth — a characteristic that explains why earlier shallow drilling may not have fully captured the system's extent.

Geophysical Target Status Summary

Understanding the Constance Lodes: M2M's Own High-Grade Discovery

The most significant development in Calypso's recent history is M2M's 2022–2023 diamond drilling program, which defined the Constance Lodes at the T3 geophysical target — a blind, down-plunge 400 m extension of the T2 target. The Constance Lodes comprise stacked, continuous gold-mineralised lodes within a porphyry–magnetite-siltstone corridor.

The drilling delivered multiple compelling intercepts, with the highest-grade result to date coming from wedge hole 22CALDD0011W1, which targeted the down-plunge extension of the main Constance Lode.

Selected High-Grade Intercepts — M2M 2022–2023 Diamond Drilling (Constance Lodes, T3)

All intercepts are reported as downhole widths and do not represent true widths. Drill holes were oriented approximately perpendicular to the interpreted mineralised structures.

What makes these results particularly significant is their depth. High-grade mineralisation confirmed at over 350 m below surface demonstrates the system's vertical extent — and critically, the Constance Lodes remain open along down plunge, meaning further drilling could extend the known mineralised envelope.

Furthermore, the T3 discovery is not included in the existing 2019 Exploration Target, which was based solely on T1 and T2 data. This means any future Mineral Resource estimate has the potential to incorporate T3 mineralisation as an additional contribution.

What Is an Exploration Target — and Why Does It Matter?

The Concept Explained for New Investors

An Exploration Target is a preliminary estimate of the potential quantity and grade of mineralisation within a defined area, based on available geological data. It is not a formal Mineral Resource — it has not yet met the rigorous data density, geological modelling, and quality assurance requirements needed to be classified under the JORC 2012 Code.

Think of it as the geological foundation — a well-informed assessment of what might be there, based on drilling, geophysics, and structural interpretation, but requiring further systematic work to confirm.

Why it matters to investors: An Exploration Target signals that there is sufficient geological evidence to justify a dedicated drilling program aimed at defining a formal Mineral Resource. Conversion of an Exploration Target to a JORC-classified Mineral Resource is a major value-creating milestone in the life of an exploration project — it is typically associated with significant re-rating of the asset.

In Calypso's case, the 2019 Exploration Target of 153,000–279,000 oz Au across T1 and T2 was estimated by independent consultants BMGS. The upcoming Mt Malcolm Mines Calypso Gold Prospect drilling program near Leonora WA is specifically designed to generate the data density required to attempt that conversion.

Quick Glossary

• JORC 2012: The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves — the industry standard for resource reporting in Australia.
• Mineral Resource: A formal, JORC-compliant estimate of in-situ mineralisation with reasonable prospects for economic extraction.
• Orogenic Gold: A type of gold deposit formed by hydrothermal fluids during tectonic events — the dominant gold deposit style in the Yilgarn Craton.
• RC Drilling (Reverse Circulation): A cost-effective drilling method that produces rock chip samples — commonly used for pre-collaring holes before deeper diamond drilling.
• Diamond Drilling: A core-recovery drilling method that provides high-quality geological samples and is used to define mineralisation geometry and grade at depth.
• Down Plunge: The direction in which a mineralised body extends deeper into the earth along its structural orientation.
• CIL (Carbon-in-Leach): A gold processing method where carbon is used to adsorb dissolved gold from a cyanide leach solution.

The Drilling Program: Designed to Define a Maiden Resource

The Mt Malcolm Mines Calypso Gold Prospect drilling program near Leonora WA is structured to systematically advance Calypso from an exploration-stage prospect toward resource definition. The program will combine RC pre-collars with diamond tail drilling, and extends well beyond simple resource drilling to include the studies required for a comprehensive geological understanding of the deposit.

Program Objectives

1. Systematic infill and extensional drilling at T1 and T2 to support conversion of the existing Exploration Target to a Maiden JORC 2012 Mineral Resource
2. Test mineralisation to a depth extent of 150–180 metres below surface at T1 and T2
3. Structural interpretation and 3D geological modelling
4. Delivery of a Maiden Mineral Resource Estimate
5. Metallurgical testwork results to assess processing characteristics
6. Geotechnical assessment to support future development studies

Planned Use of Capital Raise Proceeds

A key strategic element of the announcement is that all pre-drilling activities are advancing in parallel with the capital raise — including contractor tendering, regulatory submissions, and geological model updates. This means no time is wasted between funding close and first drill turn, demonstrating operational discipline and urgency.

Deep Historical Pedigree: Decades of Validation from Major Operators

Calypso's geological credentials are not new. The prospect has been systematically explored by some of Australia's most credible resource companies over four decades.

BHP Malcolm Joint Venture (1983–1988) conducted the most extensive early-stage programme at Calypso, comprising 14,043 m RAB, 6,452 m aircore, and 3,440 m diamond drilling. Selected intercepts from this programme include:

North Ltd (1996–1997) conducted further testing using aircore, RC, and diamond drilling. Selected intercepts include:

Historical results are presented as originally reported by the respective operators. They have not been independently verified by M2M and are provided for contextual and historical reference only.

The consistent presence of multi-gram intercepts across multiple operators, multiple time periods, and multiple target zones speaks to the geological robustness of the system — and reinforces why a modern, systematic resource definition program is a logical next step.

Malcolm Project Context: A Broader Platform for Value Creation

Calypso is the flagship exploration asset within M2M's Malcolm Project, a broader landholding in the Leonora region. The project already hosts a combined Maiden Mineral Resource Estimate across the Golden Crown and Dumbarton prospects.

Malcolm Project — Golden Crown & Dumbarton MRE Summary

Reported within conceptual pits at 0.5 g/t Au cut-off. Source: M2M ASX Release, 12 March 2026.

This existing resource base, while modest in scale, demonstrates M2M's capacity to deliver formal JORC resource estimates — and establishes the framework within which Calypso's potential resource would sit.

Adding further strategic context, M2M has commissioned financial and technical studies to assess the refurbishment and commissioning of a 500,000 tonnes per annum CIL gold processing plant acquired by the company in December 2025. Should Calypso deliver a substantial resource, the prospect of in-house processing capability on the same project platform would represent a meaningful step toward self-sufficiency.

The Investment Case: Why Calypso Deserves Attention

Several converging factors make this announcement a meaningful inflection point for M2M's investment case.

1. An Advanced, Well-Defined Geological System with Clear Resource Potential

Calypso has more than 20,000 m of historical drilling, a defined 2019 Exploration Target, and a structural framework that provides predictable targeting geometry. This is not speculative — it is a system with demonstrated mineralisation seeking formal definition.

2. A High-Grade Discovery That Extends the Known System

The Constance Lodes at T3, discovered and defined by M2M, returned the highest-grade composite intercept in the project's history — 16.21 m at 4.01 g/t Au at over 350 m depth. This is not captured in the existing Exploration Target, meaning any future resource estimate has the potential to be larger than the baseline suggests.

3. Multiple Untested Targets Representing Genuine Exploration Upside

T4 and the Northern Limb remain completely undrilled. These represent optionality beyond the current drilling program and support a longer-term exploration narrative for the Mt Malcolm Mines Calypso Gold Prospect drilling program near Leonora WA.

4. Operational Readiness to Move Quickly Post-Funding

Pre-drilling activities running in parallel with the capital raise eliminates lead time. The company has demonstrated a clear understanding that capital markets reward execution speed.

5. Proximity to Infrastructure and a Favourable Geological Address

The Leonora region is one of Western Australia's most established gold-mining districts, with access to established regional infrastructure. Mining Lease Applications have already been lodged over 475 ha of the tenements most relevant to Calypso.

6. Processing Infrastructure in Feasibility

Studies underway to assess a 500,000 tpa CIL plant acquired in December 2025 add a potential future processing pathway to the investment narrative. In addition, the existing MRE across Golden Crown and Dumbarton provides a platform upon which Calypso's resource potential can meaningfully build.

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