Great Southern Mining Accelerates 20,000m Gold Drilling Campaign Across Key Projects

Major Drilling Campaign Targets Western Australia Gold Extensions

Great Southern Mining (ASX:GSN) is ramping up exploration with a substantial 20,000-metre reverse circulation (RC) drilling program across its flagship Duketon gold projects in Western Australia. The campaign focuses on expanding mineralisation at the Golden Boulder and Amy Clarke discoveries, both of which exhibit significant strike lengths but remain shallowly drilled to date.

Golden Boulder, sitting on a northwest structural trend hosting multiple multi-hundred-thousand-ounce deposits, boasts a 3.5-kilometre strike of gold mineralisation. Previous drilling has yielded high-grade hits, including 5 metres at 14.6 grams per tonne (g/t) gold and 6 metres at 6.7 g/t gold near surface. However, drilling has only tested to depths of less than 100 metres, leaving substantial potential at depth and along strike. The July 2026 RC program aims to infill and extend these zones, with up to 15,000 metres planned to probe deeper mineralisation and untested southern extensions.

Amy Clarke Emerges as a Significant Gold Trend

Immediately following Golden Boulder, drilling will shift to the Amy Clarke prospect, where the gold mineralised trend now stretches over 4.7 kilometres and remains open to the south. Mineralisation starts from surface but has only been tested to an average depth of 50 metres. Notably, Amy Clarke lies less than 12 kilometres from Regis Resources’ Garden Well processing facility, positioning it well for potential near-term development. Significant intercepts from past campaigns include 17 metres at 1.4 g/t gold from 20 metres depth and 2 metres at 23.9 g/t gold from 10 metres, underscoring the prospect’s promise. The program will include up to 3,000 metres of RC drilling to test step-out and deeper zones of gold mineralisation.

Mon Ami Project Shows Potential for High-Grade Extensions

At the Mon Ami Gold Project, located approximately 10 kilometres east of the Granny Smith mill, extensional RC drilling is underway targeting a 55,000-ounce JORC Mineral Resource. The project benefits from granted mining licences and completed heritage and environmental studies, with trucking access to multiple nearby processing plants. Great Southern Mining views Mon Ami as a potential analogue to the nearby high-grade Ida H deposit, known for its exceptional grades of 22.6 g/t gold. Early signs indicate increasing grade with depth, and upcoming drilling will test extensions to high-grade zones and potential parallel lodes.

Edinburgh Park JV with Gold Fields Targets Giant Intrusive Gold Systems

In Queensland, the Edinburgh Park joint venture with global miner Gold Fields Ltd (NYSE:GFI) is advancing diamond drilling at the Mt Dillon target. Spanning over 1,500 square kilometres, the tenure is highly prospective for large intrusive-related gold-copper-silver systems. Gold Fields is investing $15 million to earn a 75% interest, leveraging its porphyry expertise to explore multiple targets identified by Great Southern Mining. Mt Dillon hosts a prominent induced polarization anomaly beneath a quartz lithocap, interpreted as a preserved porphyry or epithermal system analogous to major discoveries like Quebradona in Colombia and Valeriano in Chile. Drilling commenced in July 2026, marking a significant step in exploring this under-explored province.

Strategic Landholding and Financial Position

Great Southern Mining commands a substantial 909 square kilometre landholding in the Laverton District, strategically situated between Regis Resources’ 12 million ounce Duketon camp and Genesis Mining’s 6 million ounce Laverton tenure. The proximity to multiple operating and planned gold processing facilities enhances the development potential of its discoveries.

As of July 2026, GSN has a market capitalisation of approximately A$26 million, with cash reserves of A$5.6 million and no debt. The company also holds deferred payments and contingent receivables totalling A$5 million, providing a solid financial footing to fund ongoing exploration activities.