Great Southern Mining (ASX:GSN) reported a substantial extension of gold mineralisation at its Golden Boulder discovery in Western Australia, alongside the commencement of deep diamond drilling co-funded by the WA Government. The company also raised A$4.2 million to fuel ongoing exploration.
- Golden Boulder gold mineralisation extended to ~3.5km strike
- Deep diamond drilling program underway, co-funded by WA Exploration Incentive Scheme
- A$4.2 million equity placement completed with management participation pending approval
- Upcoming RC drilling planned at Golden Boulder and Amy Clarke prospects
- Drilling at Mt Dillon in Queensland scheduled post-wet season
Golden Boulder Drilling Reveals Extended Gold Mineralisation
Great Southern Mining (ASX:GSN) has significantly expanded the known gold mineralisation at its Golden Boulder discovery within the Duketon Gold Project, Western Australia. Results from a 5,234-metre reverse circulation (RC) drilling campaign completed in 2025 have extended the mineralised strike to approximately 3.5 kilometres. Noteworthy intercepts include 6 metres at 6.7 g/t Au from 48 metres, including a standout 1 metre at 34.5 g/t Au, and multiple other intervals exceeding 5 g/t Au over several metres.
The drilling targeted the Main Line mineralisation, achieving all three core program objectives: infill and extensional drilling to support a maiden JORC Mineral Resource, extending mineralisation to the south where historic drill coverage was sparse, and first-pass drilling of southern structural offsets. These results confirm continuity of gold mineralisation along a structurally complex corridor that hosts significant deposits on neighbouring Regis Resources’ tenure.
Deep Diamond Drilling Begins with Government Support
This drilling initiative follows the company’s earlier announcement of government-backed deep drilling at Golden Boulder, marking a pivotal step in delineating the source of multiple gold trends within the Duketon Belt. The structural setting, including mantle-tapping shears and quartz-dolerite intrusions, is considered highly prospective for significant gold deposits.
Capital Raise to Accelerate Exploration Momentum
GSN bolstered its exploration war chest with a A$4.2 million equity placement during the quarter, with directors and management committing an additional A$0.4 million subject to shareholder approval. The company ended the quarter with A$5.6 million in cash, positioning it well to advance drilling programs. Shares on issue now total over 1.14 billion, with performance rights and options reflecting ongoing employee incentives.
This capital injection aligns with the company’s plans for a substantial 10,000 to 15,000-metre RC drilling campaign at Golden Boulder following the diamond program, alongside maiden RC drilling at the Amy Clarke prospect, which itself hosts gold mineralisation over a 4.7-kilometre strike. Amy Clarke drilling is scheduled for the June quarter, aiming to test continuity and high-grade zones.
Queensland Targets and Regional Exploration Progress
In Queensland, GSN is preparing to commence drilling at the Mt Dillon target in May 2026, following the northern wet season. Mt Dillon is the highest-ranked target within the Edinburgh Park Project, featuring a significant induced polarization anomaly indicative of a large intrusive-related gold system. This drilling restart follows earlier work that did not locate the source of surface gold anomalies but identified promising alteration zones.
GSN’s joint venture partner, Gold Fields Ltd, retains the option to earn a 75% interest in Edinburgh Park by funding A$15 million in exploration over six years. The upcoming drilling and further geophysical surveys, including over the Rhyolite Hill target, aim to unlock this province-scale opportunity.
East Laverton and Other Project Updates
At the East Laverton Nickel-Gold Project, GSN completed an 811-metre diamond hole at the Diorite Hill layered intrusive complex targeting reef-style PGE-nickel-copper mineralisation. Preliminary logging indicates complex mafic-ultramafic sequences with trace sulphides and an unidentified silver-coloured mineral; assays are expected in the coming weeks.
Meanwhile, the Camel Hump target on the western edge of Duketon has revealed gold, silver, and copper soil geochemical anomalies over approximately 800 samples, with anomalies open to the north-west. A heritage survey is planned to support further soil sampling and drill targeting.
GSN also continues to advance the Mon Ami Gold Project, which holds a JORC resource of 55,500 ounces at 1.11 g/t Au. Extensional RC drilling is planned to test open mineralisation zones north and down-plunge of the existing resource, with historic intercepts including 2 metres at 27.5 g/t Au from depth.
Financial Position and Corporate Details
The company reported operating cash outflows of A$295,000 for the quarter and investing outflows of A$1.1 million, primarily on exploration and evaluation. Financing activities, including the placement, generated net inflows of A$4 million. GSN holds 0.38 million shares in Revolver Resources Limited (ASX:RRR), valued at approximately A$28,000.
Director fees and related party payments are disclosed with transparency, including office lease payments to a related entity and salary costs reallocated to exploration expenditure. The company’s strong cash position supports an estimated 4.2 quarters of funding at current expenditure levels.
This quarterly update builds on GSN’s recent progress, including the government-backed deep drilling launch at Golden Boulder and the substantial capital raise to accelerate exploration, as detailed in the company’s prior announcements.
Investors will be watching the assay results from the deep diamond drilling and the outcome of the upcoming shareholder meeting to approve director participation in the placement, which will shape the pace and scale of GSN’s exploration programs through 2026.
deep diamond drilling at Golden Boulder marked a key milestone for the company’s strategy to unlock deeper mineralisation and define maiden resources, setting the stage for an active and data-driven exploration year.
Bottom Line?
GSN’s extended gold strike and government-backed deep drilling position it well for resource definition, but pending assays and shareholder approvals will be critical near-term catalysts.
Questions in the middle?
- Will the deep diamond drilling assays confirm significant high-grade mineralisation at depth?
- How will the shareholder vote on director participation in the placement influence capital availability?
- Can upcoming RC drilling at Golden Boulder and Amy Clarke translate the extended strike into a maiden JORC resource?