Granodiorite the new gold standard at Ramelius’ Mount Magnet

A shift in geological thinking is reshaping exploration at Ramelius Resources’ Mount Magnet Gold Camp, where the company is moving beyond traditional banded iron formation (BIF) deposits to focus on granodiorite-hosted mineralisation. This strategic change, outlined by executive general manager – exploration, Peter Ruzicka, at the RIU Explorers Conference in Fremantle, is unlocking new opportunities in one of Australia’s most established goldfields.

The significance of this shift lies in how Ramelius is targeting gold-bearing structures within the Boogardie Dome, using a combination of deep drilling and passive seismic ambient noise tomography (ANT) to refine exploration efforts. With recent discoveries at Eridanus and Bartus East, the company is proving that Mount Magnet still holds substantial potential beyond its historic BIF-hosted deposits.

“Eridanus was a brownfields discovery in 2017 and is still growing,” Ruzicka said. “A milestone resource update completed in May last year comprised 21 million tonnes at 1.5 grams per tonne gold.”

The success at Eridanus, which now boasts 1.2 million ounces outside of the recently mined open pit, has reinforced granodiorite-hosted mineralisation as a primary exploration focus. This, coupled with advances in geophysical targeting techniques, is allowing Ramelius to refine drill programs and model deeper, previously underexplored mineralised systems.

A New Geological Model

For decades, Mount Magnet’s gold deposits have been closely associated with BIF-hosted mineralisation, but the growing significance of granodiorite intrusions is changing how Ramelius approaches exploration.

Using Passive Seismic Ambient Noise Tomography (ANT), the company is mapping deeper intrusive systems to pinpoint new gold-bearing structures within the Boogardie Dome. Unlike traditional magnetics or gravity surveys, ANT allows for a clearer understanding of large-scale, buried intrusions, giving geologists a new tool to target mineralisation at depth.

“We’ve been using passive seismic ambient noise tomography to help us identify deeper, intrusive targets in the Mount Magnet area,” Ruzicka explained. “It gives us another tool in addition to traditional geophysical layers.”

The integration of ANT with drill targeting is already influencing how Ramelius approaches drilling programs at Mount Magnet, allowing for more precise step-out drilling and the identification of high-priority targets beneath existing resources.

Drilling Success and Future Prospects

The ongoing drilling campaign at Mount Magnet is focused on expanding the Eridanus deposit, where step-out drilling is being used to define deeper extensions beneath the existing open pit. At the same time, drill rigs are testing ANT-defined granodiorite-hosted targets within the Boogardie Dome, aiming to confirm the presence of additional mineralisation at depth. Geologists are also investigating the structural controls of high-grade zones, particularly where granodiorite intrusions intersect shear structures, as these settings have already proven to be highly prospective.

With an ore reserve of 570,000 ounces and a 10-year mine plan, the continued expansion of granodiorite-hosted mineralisation could significantly extend the life of Mount Magnet’s operations.

Beyond Mount Magnet

While Mount Magnet remains central to Ramelius’ exploration strategy, the company is also conducting high-impact drilling campaigns across its Cue, Penny, and Rebecca-Roe projects.

At the Cue Gold Project, drilling is focused on defining extensions at Break of Day, which remains a high-grade open-pit deposit with a resource grade of 8.2g/t and a reserve grade of 4.5g/t. Additional step-out drilling is targeting mineralisation along strike to determine the continuity of high-grade zones beyond the current resource boundary.

Exploration at the Penny Gold Project is also progressing, with diamond drilling targeting extensions of the Penny West lode. Recent results suggest the potential for additional lode repetitions along the Penny Shear Zone, prompting further drilling to test the structural continuity of mineralisation across the tenement package.

At the Rebecca-Roe Gold Project, drilling is supporting the recent pre-feasibility study (PFS) results, which confirmed an 850,000-ounce open-pit reserve. The focus now is on converting inferred underground resources into reserves, with deeper drilling underway to evaluate the underground potential ahead of the definitive feasibility study (DFS) scheduled for late 2025.

Future Exploration and Outlook

With $40–$50 million committed to exploration and resource development, Ramelius is refining its approach to resource expansion through advanced drilling and geophysical techniques. The company's growing reliance on granodiorite-hosted mineralisation at Mount Magnet is expected to shape future drilling programs, potentially unlocking new high-grade zones within the Boogardie Dome.

“We have a supportive management and board, and we have a highly prospective tenement package with multiple exploration opportunities,” Ruzicka said.

By refining its exploration and drilling methodologies, Ramelius is positioning itself for long-term production growth, while integrating new geological insights and geophysical technologies to enhance targeting and discovery success.

Craig Oliver Award Recognition

In recognition of its commitment to exploration and mining excellence, Ramelius was awarded the 2025 Craig Oliver Award during the conference. Named in memory of Craig Oliver, the award honours a small-to-mid-cap Australian mining company that has demonstrated leadership across exploration, corporate responsibility, and community engagement.