Great Southern Mining is kicking off its largest-ever drill campaign, a 20,000m reverse circulation program across its Duketon and Mon Ami gold projects in WA. The move follows recent diamond drilling at the Golden Boulder discovery that delivered a key geological reinterpretation, suggesting a steeper dip to mineralisation and pointing to significant depth potential.
Great Southern Mining is set to kick off the largest drill program since acquiring its Duketon tenure in 2021. A first phase of up to 20,000 metres in reverse circulation drilling is slated to begin next week at the company’s Duketon and Mon Ami gold projects in Western Australia’s prolific Laverton region.
The major campaign follows hot on the heels of a recent diamond drill hole at the company’s Golden Boulder discovery. The new find delivered a crucial geological reinterpretation, suggesting gold lodes in the area dip more steeply than previously thought, opening up the prospect of significant mineralisation at depth.
The upcoming program will aim to expand the company’s emerging discoveries at Golden Boulder and Amy Clarke, in addition to extending the known mineralisation at its Mon Ami gold project.
The company is cashed up for the campaign after completing a $4.6 million equity placement in March.
At Golden Boulder, a recent diamond hole extended mineralisation by 40m down-dip, returning multiple stacked lodes, including 2.25m at 2.04 grams per tonne (g/t) gold from 108.94m, featuring a higher-grade core of 0.72m going 4.07g/t gold.
Management says structural measurements from the hole indicate a steeper dip up to 85 degrees for the gold lodes, rather than the earlier flatter interpretation and says the new geological read “bodes well for significant depth potential”, guiding the upcoming drilling.
Golden Boulder sits on a prominent structural trend that also hosts Regis Resources’ monster 2-million-ounce-plus Rosemont gold mine, in addition to its Baneygo and Ben Hur deposits, each containing roughly 390,000 ounces of gold.
Mineralisation at Golden Boulder has been traced along three parallel trends known as the Main line, Eastern line and Ogilvies. Previous drilling from 2025 along the Main Line trend hit some promising intercepts, including 5m at 14.6g/t gold from 41m, 5m at 5.1g/t gold from 25m and 6m at 6.7g/t gold from 48m.
The new campaign is aimed at proving up continuity in the northern 2km of the Main Line trend, extending mineralisation at depth along the same trend and infilling sparsely drilled sections in its southern part. It will also explore for mineralised extensions at depth and to the south along the trend known as the Eastern Line.
At the nearby Amy Clarke discovery, previous aircore drilling in 2021 and 2025 defined shallow gold mineralisation, generally less that 50m below surface, in partly-weathered and near-fresh rock over an impressive 4.7km of strike.
Previous best hits in 2025 included 17m at 1.4g/t gold from 20m, 3m at 5.7g/t gold from 8m and a cracking 2m assaying 23.9g/t gold. The upcoming program will test for extensions both at depth and along strike.
The company has interpreted the gold mineralisation as hosted in steep quartz veins with disseminated sulphides on the contact of sedimentary schists and porphyries.
Great Southern will also point the drill bit at its Mon Ami gold project, south of the Golden Boulder and Amy Clarke deposits, which already hosts a JORC-compliant mineral resource of 1.56 million tonnes at 1.11g/t gold for 55,500 ounces.
Mon Ami sits on the Barnicoat Shear, which is also home to the historic high-grade Ida H mine, which produced 170,650 ounces of the yellow metal at a stunning 22.6g/t gold.
The gold is shear-hosted in steep, west-dipping quartz-carbonate veins and accompanying disseminated sulphides, with ore shoots occurring on the contact of metasedimentary and basalt geological units.
Great Southern views the old Ida H mine as a strong analogue for Mon Ami’s depth potential. The possible connection was hinted at by a previous deeper hole, which gave up 10m at 2.7g/t gold from 241m.
In a final flourish, drilling will test the nearby Blanc Platt target, where previous shallow hits included 2m at 4.8g/t gold from 70m, 2m at 3.23g/t gold from 100m and 2m at 1.86g/t gold from 20m depth.
The company has also received $114,000 from a WA Government Exploration Incentive Scheme (EIS) to co-share the cost of a deep diamond hole at its Diorite target in the East Laverton project.
Great Southern Mining managing director Matthew Keane said: “The recent diamond drilling at Golden Boulder has greatly improved our understanding of the structural and geological settings that host gold mineralisation. On the Golden Boulder Main Line, this drilling has extended gold mineralisation down-dip by 40m, but more importantly, led to a reinterpretation of the orientation of gold bearing structures, which bodes well for significant depth extensions.”
With a war chest full of cash and a conga line of drill targets across its Duketon and Mon Ami projects, Great Southern looks set to generate plenty of news flow in the coming months.
The company’s fresh geological interpretation at Golden Boulder could be a real game-changer for the existing deposit and potentially for the broader area if it unlocks a much bigger system at depth than previously imagined.
As the drill bit begins hammering downwards next week, all eyes will be on whether Great Southern’s new thinking can translate into discovery.
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