Great Southern Mining (ASX: GSN) is embarking on its largest drilling campaign to date at its Western Australian gold projects, aiming to extend mineralisation at Golden Boulder, Amy Clarke, and Mon Ami. Recent diamond drilling has revealed deeper gold potential, underpinning the aggressive program.
- 20,000m Reverse Circulation drilling underway
- Golden Boulder mineralisation extended 40m down-dip
- Amy Clarke gold zone open along 4.7km strike
- Mon Ami JORC resource of 55.5koz gold targeted for extension
- Fully funded following $4.6 million equity raise
Major Drilling Campaign Targets Multi-Kilometre Gold Systems
Great Southern Mining (ASX:GSN) has kicked off a substantial Reverse Circulation (RC) drilling program spanning up to 20,000 metres across its Duketon and Mon Ami gold projects in Western Australia. This marks the company’s largest drilling effort since acquiring the Duketon tenure in 2021, with a clear focus on expanding the footprints of its emerging gold discoveries.
The program aims to significantly grow the Golden Boulder and Amy Clarke prospects, where recent campaigns have delineated gold mineralisation over strike lengths of 3.5km and 4.7km respectively. Both remain open along strike and at depth, with drilling to date limited to less than 150 metres below surface, underscoring the potential for substantial extensions.
Diamond Drilling Unlocks Depth Potential at Golden Boulder
A recently completed diamond drill hole at Golden Boulder (26GBDD001) has extended known mineralisation by 40 metres down-dip, delivering key insights into the structural controls of the deposit. The hole intersected multiple stacked gold lodes hosted within intensely sheared basaltic units, with significant intercepts including 2.25 metres at 2.04 g/t Au, featuring a high-grade 0.72 metre interval at 4.07 g/t Au.
Crucially, structural measurements from this hole have prompted a reinterpretation of the gold-bearing lodes’ orientation, indicating a steeper dip towards the east-northeast. This geometry suggests enhanced depth potential within the highly prospective shear zone sandwiched between the Betelgeuse and Rosemont faults.
Amy Clarke and Mon Ami Projects Offer Further Growth Avenues
At Amy Clarke, shallow aircore drilling has outlined gold mineralisation over a 4.7km strike, predominantly near surface. Upcoming RC drilling will test for extensions at depth and along strike in zones of higher-grade quartz vein-hosted mineralisation. The project’s proximity to Regis Resources’ Garden Well processing facility adds strategic value.
The Mon Ami project, situated 12km southeast of Laverton and on a granted mining lease, holds a JORC Mineral Resource of 1.56 million tonnes at 1.11 g/t Au for 55,500 ounces. Drilling will focus on extending known mineralisation at depth and along strike, including at the Blanc Platt target to the north. Historical intercepts such as 10m at 2.7 g/t Au and 2m at 25.1 g/t Au hint at robust high-grade potential. Mon Ami’s location within trucking distance of multiple operating mills enhances its development prospects.
Funding Secured to Drive Aggressive Exploration
Great Southern is fully funded for this drilling campaign following the settlement of the final tranche of a $4.6 million equity placement in early June 2026. The company’s Managing Director, Matthew Keane, emphasised the team’s enthusiasm to build on recent successes, noting that the portfolio’s strategic location near existing processing infrastructure provides a compelling platform for value creation.
Keane highlighted that the new structural insights from diamond drilling at Golden Boulder have reshaped the understanding of the deposit’s orientation, which bodes well for unlocking significant depth extensions. The drilling at Mon Ami is also poised to test extensions on a granted mining lease with several high-grade intercepts to follow up on.
Geological Complexity and Exploration Incentive Scheme Support
Alongside the RC campaign, a second diamond hole (26OGDD001) co-funded by the Western Australian Government’s Exploration Incentive Scheme (EIS) was drilled to provide geological context north of Golden Boulder. While this hole did not intersect significant gold mineralisation, it revealed a complex sequence of mafic and ultramafic rocks with quartz-carbonate veining and sulphides consistent with a fertile orogenic gold setting.
The company also completed a deep diamond hole (26ELDD001) at the Diorite Hill layered intrusive complex targeting PGE-nickel-copper mineralisation, co-funded by the EIS, with assay results confirming no economic concentrations but contributing valuable geological data.
Bottom Line?
Great Southern’s ambitious drilling program, underpinned by fresh structural insights and solid funding, sets the stage for potential resource growth, though the timing and scale of any development remain to be seen.
Questions in the middle?
- Will the upcoming RC drilling confirm the interpreted steep dip and continuity of gold lodes at Golden Boulder?
- How might the Mon Ami project’s proximity to existing mills influence potential monetisation strategies?
- What further structural complexities could emerge from ongoing diamond drilling and how will these impact resource estimation?