Great Southern Mining Ltd
- ASX Code: GSN
- Market Cap: $32,158,893
Great Southern Mining Drills Into Amy Clarke as Maiden RC Program Gets Underway
Great Southern Mining (ASX: GSN) has commenced an 18-hole, approximately 2,300-metre Reverse Circulation (RC) drilling program at its Amy Clarke discovery, marking the first time this drilling method has been deployed at the target. The Great Southern Mining Amy Clarke RC drilling program at Duketon Gold Project follows two aircore drilling campaigns in 2021 and 2025 that defined gold mineralisation over a 4.7-kilometre strike length, with intercepts to date rarely extending below 50 metres from surface.
The maiden RC program represents a step-change in exploration intensity at Amy Clarke, part of Great Southern Mining's 100% owned Duketon Gold Project in the Laverton District of Western Australia. For a discovery built almost entirely on shallow aircore data, testing what lies beneath is the logical next phase.
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Why Amy Clarke Has Captured Attention
Amy Clarke sits within a well-established gold-producing corridor. The discovery is located approximately 12 kilometres south of Regis Resources' Garden Well processing facility and approximately 3.5 kilometres directly south of Regis Resources' Erlistoun gold mine, placing it within the broader Duketon Gold Belt.
The company notes that the tenement was only granted in 2021, and very little historical exploration had been conducted at Amy Clarke prior to that. Unlike many defined deposits elsewhere in the Duketon Belt, there are no historical shafts or workings at the site. Targets were instead defined through systematic surface geochemistry, geological mapping and structural interpretation of geophysical surveys, before being tested with aircore drilling.
The Aircore Results That Built the Case
The two aircore programs conducted in 2021 and 2025 returned a series of gold intercepts across the mineralised strike. Notably, virtually all of this drilling has been confined to the top 50 metres of ground surface, leaving deeper mineralisation largely untested.
Reported intercepts include:
| Hole ID | Intercept | Grade (Au) | From (m) | Notes |
|---|---|---|---|---|
| 25ACAC0105 | 17m | 1.4 g/t | 20m | Incl. 1m at 11.2 g/t and 4m at 2.2 g/t |
| 21ACAC147 | 8m | 6.7 g/t | 33m | Incl. 4m at 12.5 g/t |
| 25ACAC0007 | 2m | 23.9 g/t | 10m | Shallow high-grade intercept |
| 25ACAC0132 | 3m | 5.7 g/t | 8m | Plus 1m at 3.2 g/t from 37m |
| 25ACAC0138 | 1m | 10.3 g/t | 32m | – |
| 25ACAC0057 | 11m | 1.2 g/t | 25m | Incl. 6m at 1.7 g/t |
| 25ACAC0144 | 11m | 0.7 g/t | Surface | Incl. 2m at 2.9 g/t from 9m |
The RC holes have been designed to step out along strike and test depth beneath the zones of higher-grade mineralisation identified from aircore drilling. The stated objectives of the program are to define the orientation of mineralisation and better understand the geological controls involved.
What Is RC Drilling and Why Does It Matter Here?
Reverse Circulation (RC) drilling is a method in which drill cuttings are returned to the surface through the inside of the drill rods using pressurised air, producing dry rock chip samples from depth. It is generally faster and less costly than diamond drilling, which makes it a common choice for initial depth-testing once a target has been defined by shallower methods.
Aircore drilling, the technique used in the 2021 and 2025 campaigns at Amy Clarke, is typically limited to shallow depths and softer ground conditions. It is well suited to rapidly scanning large areas and identifying anomalies; however, it is not designed to reliably test mineralisation at depth or provide detailed structural information.
With the 18-hole RC program now underway, the Great Southern Mining Amy Clarke RC drilling program at Duketon Gold Project is testing below the shallow zone for the first time to assess whether the higher-grade intercepts observed near surface continue at depth. The aircore work identified the target; consequently, the RC program is intended to help determine its full extent.
A Company Running Multiple Exploration Fronts
Amy Clarke is one of several active work streams for Great Southern Mining. In addition to this program, the company has a number of assay results pending and additional drilling programs underway across its portfolio.
| Project | Status | Holes / Metres | Notes |
|---|---|---|---|
| Amy Clarke (Duketon) | RC drilling underway | 18 holes / ~2,300m | Maiden RC program |
| Golden Boulder (Duketon) | Assays pending | 38 holes / 4,726m | Results expected in coming weeks |
| Mon Ami | Assays pending | 16 holes / 3,089m | Results described as imminent |
| Edinburgh Park (QLD) | Diamond drilling underway | Up to 1,300m | Funded and managed by G-Ex Resources, a Gold Fields Ltd subsidiary |
Assays are pending for 16 holes (3,089 metres) drilled at the Mon Ami Gold Project, located 12 kilometres south of Laverton, with results described as imminent. Furthermore, assays are also pending for 38 holes (4,726 metres) completed across the northern 1.1 kilometres of the 3.5-kilometre Golden Boulder mineralised strike, with results expected in the coming weeks.
A further 68 holes are planned for the broader Golden Boulder area, to be drilled following completion of the Amy Clarke program. Separately, diamond drilling is underway at the Mt Dillon target within the Edinburgh Park Project in northern Queensland. This program will initially comprise up to 1,300 metres and is being funded and managed by G-Ex Resources, a wholly owned subsidiary of Gold Fields Ltd.
Sequencing Decisions in the Drilling Program
Great Southern Mining opted to commence the Amy Clarke RC program ahead of completing the full Golden Boulder drilling campaign. The company stated this decision was made to expedite results and enable potential follow-up drilling at Amy Clarke while the rig remains on site — an approach intended to reduce cost and logistical disruption between programs.
Great Southern Mining stated in its announcement that the decision to commence Amy Clarke drilling ahead of finishing Golden Boulder was made "to expedite results for potential follow-up drilling at Amy Clarke whilst the drill rig is on site."
The Duketon Belt Context
The Duketon Gold Belt in the Laverton District is a recognised gold-producing region hosting operations including Regis Resources' Garden Well and Erlistoun mines. Amy Clarke's position, approximately 3.5 kilometres south of the Erlistoun mine, places the discovery firmly within this broader mineralised corridor.
According to Great Southern Mining, all of its projects across the Laverton district and northern Queensland are located within 40 kilometres of operating mills and major operations — a factor the company has highlighted as relevant to the logistical setting of its exploration activities.
Key Upcoming Catalysts to Watch
The coming weeks are expected to bring a concentrated run of exploration newsflow for Great Southern Mining, based on the timelines outlined in the announcement:
- Mon Ami assay results (16 holes / 3,089m), described as imminent
- Golden Boulder assay results (38 holes / 4,726m across 1.1km of a 3.5km strike), expected in coming weeks
- The Great Southern Mining Amy Clarke RC drilling program at Duketon Gold Project (18 holes / ~2,300m), currently underway
- Edinburgh Park diamond drilling at Mt Dillon, funded and managed by G-Ex Resources
- A further 68 holes planned for the Golden Boulder area, to follow completion of Amy Clarke drilling
What This Means Going Forward
Great Southern Mining's work at Amy Clarke since the tenement was granted in 2021 has progressed through surface geochemistry, structural mapping, geophysical interpretation and two rounds of aircore drilling. The maiden RC program now underway is the first attempt to test whether the shallow gold intercepts recorded to date extend to greater depths, given that prior drilling has rarely penetrated below 50 metres.
Alongside this, the company has pending assay results from Mon Ami and Golden Boulder, along with an ongoing diamond drilling program at Edinburgh Park funded and managed by a subsidiary of Gold Fields Ltd. Taken together, these programs are set to generate a series of exploration updates across Great Southern Mining's Western Australian and Queensland assets in the near term.
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Glossary of Key Terms
- RC Drilling (Reverse Circulation): A drilling method using pressurised air to return rock chip samples to the surface, commonly used for cost-effective testing of mineralisation at moderate depths.
- Aircore Drilling: A lighter drilling technique suited to shallow, softer ground, typically used for initial target definition at depths of around 50 to 80 metres.
- Diamond Drilling: A drilling method using a diamond-tipped core barrel to extract intact rock samples, providing detailed structural and geological information.
- g/t Au: Grams of gold per tonne of rock, the standard measure of gold grade in exploration reporting.
- Strike Length: The horizontal distance along which mineralisation has been identified at a given prospect.
- JORC Code: The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, which sets the professional standard for how ASX-listed companies report exploration data.
Want to Know More About Great Southern Mining's Duketon Gold Project?
With a maiden RC drilling program now underway at Amy Clarke, imminent assay results from Mon Ami, a substantial batch of Golden Boulder results on the horizon, and a Gold Fields-backed diamond drilling program at Edinburgh Park, Great Southern Mining (ASX: GSN) is entering a period of concentrated exploration newsflow. Investors seeking to learn more about the company's 100% owned Western Australian gold assets and broader project portfolio can visit the official website at gsml.com.au.
