Great Southern Mining Hits High-Grade Gold at Golden Boulder with 18/19 Holes
Key Takeaways
- 18 of 19 holes at Golden Boulder returned mineralised intercepts above 0.7 g/t Au, with standout hits including 10m at 2.62 g/t Au and a 2m high-grade core at 10.72 g/t Au — a 95% hit rate across the first 2,436m of a planned 14,000m RC program.
- The 19 reported holes cover only the northern 450m of a 3.5km mineralised strike, with 48 additional completed holes pending assay across the Main Line south and Eastern Line.
- Amy Clarke, a separate prospect 3km northeast of Golden Boulder with a 4.7km strike, has completed its first-ever RC program (18 holes, 2,248m) with assay results expected in coming weeks — adding a second discovery front to watch.
- Golden Boulder sits on the same interpreted geological structure as Regis Resources' Rosemont deposit (2 million ounces, 26km away), which has proven mineralisation extending to more than 700m — current Golden Boulder drilling has tested to fewer than 150m depth.
- GSN holds 100% ownership of the Duketon Gold Project with Golden Boulder located within 20km of operational gold processing facilities, preserving full upside exposure and compressing potential development economics.
High-grade gold confirmed at Golden Boulder as first assays land
Great Southern Mining (ASX: GSN) has received assay results for the first 2,436m (19 holes) of a planned 14,000m Reverse Circulation (RC) program at the Golden Boulder discovery, within the company’s 100%-owned Duketon Gold Project near Laverton, Western Australia. Drilling is ongoing, with assays pending for a further 5,428m of completed holes.
The first assay window has delivered high-grade hits and demonstrated mineralisation continuity across the northern 450m of a 3.5km mineralised strike. Standout intercepts from the 19 reported holes include:
- 10m at 2.62 g/t Au from 20m, including 2m at 10.72 g/t Au (hole 26GBRC011)
- 8m at 2.24 g/t Au from 102m, including 2m at 7.20 g/t Au (hole 26GBRC019)
- 7m at 2.45 g/t Au from 41m, including 1m at 6.91 g/t Au (hole 26GBRC003)
- 3m at 3.07 g/t Au from 105m (hole 26GBRC015)
- 3m at 3.32 g/t Au from 121m (hole 26GBRC018)
Critically, 18 of the 19 holes recorded mineralised intercepts above 0.7 g/t Au — a hit rate that is exceptional for any early-stage program, let alone one with this much strike yet to be tested.
Managing Director Matthew Keane
“These results support our view that Golden Boulder and the wider Duketon Gold Project has potential for significant scale. We know that to the north we have multi-million ounce deposits like Rosemont that extend not only along strike but at depth to approximately 700m. Golden Boulder sits on the same mineralised structure and has only been shallow tested to date.
“GSN has delineated shallow mineralisation over 3.5km with the latest round of results supporting the interpretation that the grade is continuing at depth. These latest intercepts from Golden Boulder highlight the propensity for high-grades both in the shallow oxide zone and continuing at depth into fresh rock. There is potential for a much larger gold system that could support multiple open-pit operations, all within 20km of operational gold processing facilities, and this is just at Golden Boulder.
“We also look forward to receiving the assays from the very first RC program at Amy Clarke in the coming weeks, only 3km to the north-east and currently defined over a 4.7km strike.”
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Understanding what Golden Boulder represents — and why it matters
The headline numbers are compelling, but the context behind them tells you something more important: Golden Boulder sits in one of Australia’s most proven gold corridors, and the current drilling has barely scratched the surface.
The Duketon Gold Belt — a proven address for major deposits
Golden Boulder sits on a prominent north-south structural corridor within the Duketon Greenstone Belt — a geological address that already hosts Regis Resources’ Rosemont deposit (more than 2 million ounces), Baneygo (approximately 380,000 oz), and Ben Hur (approximately 390,000 oz).
The 3.5km figure itself reflects progressive definition over multiple drilling phases, with the Golden Boulder strike extended to 3.5km in an earlier campaign that also confirmed the corridor’s structural continuity before the current 14,000m program commenced.
The area itself carries significant historical weight. Over 50 historical workings have been documented across a ~3.7km strike, with recorded production from 1900 to 1955 of 1,915 tonnes at 28.6 g/t Au for 1,761 ounces of gold. That kind of artisanal production history tells you high-grade material was accessible near surface — and that systematic modern exploration was always going to be warranted.
What RC drilling tells us — and why depth matters here
Reverse Circulation (RC) drilling is the industry-standard method for efficiently testing gold mineralisation along strike and at depth. Rather than extracting a solid core, RC drilling uses compressed air to return rock chips through an inner tube, allowing fast, reliable sampling over large areas.
What the current program has established so far matters enormously. Drilling at Golden Boulder is still shallow, with few holes exceeding 150m below surface, yet assay results have already extended mineralisation by up to 45m down dip. That’s encouraging — but the real upside question is what happens at depth.
Regis Resources’ Rosemont deposit, located just 26km from Golden Boulder, has proven mineralisation extending to more than 700m below surface. Golden Boulder sits on the same interpreted geological structure. The mineralisation at Golden Boulder is hosted across multiple stacked lodes comprising quartz veining with disseminated sulphides (pyrite and arsenopyrite) within basalt and minor dolerite units. With shallow drilling already confirming high-grade hits in both oxide and fresh rock, the depth profile remains the critical unanswered question for this project.
Scale picture sharpens — program scope and what’s still to come
The 19 holes reported in this announcement cover only the northern 450m of the 3.5km Main Line trend at Golden Boulder. A further 48 holes have been completed and are pending assay results, drilled further south along the Main Line and along the Eastern Line. That means the vast majority of the 14,000m program remains unreported.
Beyond Golden Boulder itself, the Amy Clarke prospect adds a separate emerging discovery to watch. Located just 3km northeast of Golden Boulder, 18 holes totalling 2,248m of RC drilling have been completed at Amy Clarke and are awaiting assays. The prospect covers a 4.7km mineralised strike — and this will be the very first RC program ever drilled there.
The maiden RC drilling at Amy Clarke was initiated specifically because earlier geochemical and geophysical work had flagged the prospect as a high-priority target on the same mineralised trend, making the pending first-pass assay results a particularly closely-watched data set.
Diamond drilling was also recently completed at the Mt Dillon target within the Edinburgh Park Project in northern Queensland, with core logging and processing now underway.
The near-term catalyst pipeline for GSN includes:
- Assay results from 48 additional Golden Boulder holes (Main Line south + Eastern Line)
- First-ever RC assay results from the Amy Clarke prospect (4.7km strike, 3km from Golden Boulder)
- Core logging results from Mt Dillon diamond drilling, Edinburgh Park Project, Queensland
| Prospect | Location | Program Type | Strike / Holes | Status |
|---|---|---|---|---|
| Golden Boulder (reported) | Duketon Gold Project, WA | RC Drilling | 19 holes / northern 450m of 3.5km strike | Assays received |
| Golden Boulder (pending) | Duketon Gold Project, WA | RC Drilling | 48 holes / Main Line south + Eastern Line | Assays pending |
| Amy Clarke | Duketon Gold Project, WA (3km NE of Golden Boulder) | RC Drilling (first-ever) | 18 holes / 4.7km strike | Assays pending |
| Mt Dillon | Edinburgh Park Project, QLD | Diamond Drilling | Recently completed | Core logging underway |
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Why these results sharpen the GSN investment case
The first assay tranche from Golden Boulder has done what first results need to do: confirm grade, demonstrate hit rate, and show that mineralisation continues at depth. With 18 of 19 holes returning intercepts above 0.7 g/t Au and multiple holes cutting high-grade zones exceeding 3 g/t Au, the early evidence supports the geological interpretation that a substantial system is present.
GSN holds a 100% ownership position across the Duketon Gold Project, meaning no joint venture partner dilutes the upside as the program advances. The company also notes that all projects sit within 40km of operating mills and major operations, with Golden Boulder specifically located within 20km of operational gold processing facilities — a proximity advantage that matters when the conversation eventually turns to development economics.
Managing Director Matthew Keane has characterised the system as having potential to support multiple open-pit operations. That is management’s view, not a confirmed outcome, and it should be read as such. What the data does confirm is that mineralisation is open along strike and at depth across multiple parallel trends, with the bulk of the current drill program yet to report.
Pending interpretation of results, a mineral resource estimate may be undertaken at Golden Boulder in the future — a milestone that would represent a material de-risking step for the project and give the market a formal tonnage and grade framework to assess. For now, the assay pipeline ahead is substantial, and each batch of results will add definition to what is shaping up as one of the more active exploration stories on the ASX.
Ready to Explore the Golden Boulder Discovery in Full Detail?
Great Southern Mining’s (ASX: GSN) initial RC assays have confirmed high-grade gold continuity across the northern 450m of a 3.5km mineralised strike, with 18 of 19 holes returning intercepts above 0.7 g/t Au — and the majority of the 14,000m program still to report. The pending assay pipeline, including first-ever RC results from the 4.7km Amy Clarke prospect, means the scale picture is only beginning to take shape.
Investors seeking a deeper understanding of the Duketon Gold Project’s potential can explore the full Golden Boulder investment case on Discovery Alert, including the geological context, strike extensions, and upcoming catalysts that make GSN one of the more closely watched exploration plays on the ASX right now.