Marmota Hits Up to 15 g/t Gold Near Surface in Maiden Mainwood Drilling
Key Takeaways
- Marmota's maiden Mainwood drilling has confirmed contiguous high-grade gold starting from as shallow as 24m depth, with standout intercepts of 4m @ 15 g/t Au, 4m @ 14 g/t Au, and 4m @ 13 g/t Au from sections 1–15 alone.
- These results represent only the first 15 of 84 total sections in the Stage 3 program, with 69 sections still to report and drilling still active within sections 1–15 — the full picture is far from complete.
- Program objective 2 (confirming contiguous high-grade gold in the maiden Mainwood drilling) has already been achieved, with objectives 3 and 4 (resource growth and Indicated Resource density) also described as being met with partial data.
- The Mainwood zone had seen only ~3,700m of RC drilling across 53 holes since discovery, with no drilling since 2018 — this 320-hole, ~31,000m program is a step-change in coverage for a previously under-drilled zone.
- A maiden scoping study for Marmota's Gawler Gold Project commenced on 18 November 2025, with the Greenewood/Mainwood system's near-surface, open-pittable geometry directly supporting its economic inputs.
Marmota’s maiden Mainwood drilling confirms contiguous high-grade gold
Marmota has released the first assay results from its maiden RC drilling program in the Mainwood zone, located to the south of the Greenewood gold discovery in South Australia’s Gawler Craton. The results confirm a nearly-continuous high-grade gold system starting close to surface, with multiple thick intercepts extending into fresh rock.
These are the first results from sections 1 to 15 of 84 total sections, making this Announcement 1 in a forthcoming series. Drilling within sections 1 to 15 is still ongoing, and 69 further sections are yet to be reported. According to Marmota’s Chairman, Dr Colin Rose, the results from even this early subset are already achieving program key objectives 2, 3, and 4, with objective 1 (Northern extensions and to depth) to be the subject of a separate forthcoming ASX release.
The standout intercepts from sections 1 to 15 (all are initial 4m composite assays) include:
- 4m @ 15 g/t Au from 24m (hole 26MWRC177, part of 16m @ 4.2 g/t from 24m)
- 4m @ 14 g/t Au from 32m (hole 26MWRC014, part of 20m @ 3.1 g/t from 32m)
- 4m @ 13 g/t Au from 28m (hole 26MWRC013)
- 4m @ 9.4 g/t Au from 64m (hole 26MWRC173, part of 16m @ 2.7 g/t from 56m)
- 8m @ 5.2 g/t Au from 32m (hole 26MWRC141, part of 24m @ 2.1 g/t from 24m)
- 8m @ 5.0 g/t Au from 48m (hole 26MWRC149, part of 28m @ 2.1 g/t from 36m)
Dr Colin Rose, Chairman, Marmota
“The discovery of contiguous high-grade gold, so close to surface, first in the Greenewood zone, and now also in the Mainwood zone, is very exciting. It massively extends the strike of the deposit… Greenewood/Mainwood keeps expanding with each stage of drilling, and it keeps rewarding Marmota and our shareholders.”
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Mainwood zone results at a glance
The table below summarises the top intercepts from sections 1 to 15 of Marmota’s maiden Mainwood program.
| Hole ID | From (m) | Intercept | Grade (g/t Au) | Parent interval |
|---|---|---|---|---|
| 26MWRC177 | 24m | 4m | 15 g/t Au | 16m @ 4.2 g/t from 24m |
| 26MWRC014 | 32m | 4m | 14 g/t Au | 20m @ 3.1 g/t from 32m |
| 26MWRC013 | 28m | 4m | 13 g/t Au | — |
| 26MWRC173 | 64m | 4m | 9.4 g/t Au | 16m @ 2.7 g/t from 56m |
| 26MWRC144 | 32m | 4m | 8.8 g/t Au | — |
| 26MWRC051 | 24m | 4m | 8.2 g/t Au | 16m @ 2.2 g/t from 24m |
| 26MWRC141 | 32m | 8m | 5.2 g/t Au | 24m @ 2.1 g/t from 24m |
| 26MWRC149 | 48m | 8m | 5.0 g/t Au | 28m @ 2.1 g/t from 36m |
All results are initial 4m composite assays. Downhole lengths reported; true widths are similar to intersection lengths as mineralised zones are approximately normal to hole inclinations.
What is RC drilling and why do grade and depth matter to gold investors?
Reverse Circulation (RC) drilling is the industry-standard method for gold exploration in Australia. The drill pushes a rotating bit into the ground while forcing compressed air down the outside of the drill rods, which returns rock chips up through the centre to surface. Those chips are collected at regular intervals, allowing geologists to sample the geology at precise depths continuously down the hole.
The 4m composite assays reported here mean that every four metres of drill chips were combined into a single sample and tested together. This technique gives a reliable average grade across each four-metre interval, with higher-resolution one-metre splits available for follow-up where grades spike.
“Close to surface” mineralisation matters enormously for project economics. When gold sits within 24–64m of surface, as seen repeatedly in the Mainwood results, it sits well within the depth range of open-pit mining. Open pits require stripping away the overlying rock to reach ore, and shallower ore means less waste rock, lower operating costs, and reduced upfront capital to bring a mine into production.
“Contiguous high-grade” is what separates a genuinely exciting discovery from a series of isolated hits. Contiguous means the mineralisation is connected along strike, forming one continuous zone rather than scattered pockets. For resource estimation, continuity allows geologists to interpolate grade with confidence between drill holes, which directly supports larger and higher-confidence resource classifications. Isolated pockets, by contrast, are difficult to model and often cannot support a viable mine plan.
The grades themselves stand out against typical bulk-mining thresholds. Large open-pit gold mines often operate on grades of 0.5–1.5 g/t Au. Intercepts of 13–15 g/t Au are classified as bonanza grade, orders of magnitude above what a bulk operation requires to be economical. Even the broader parent intervals running at 2–4 g/t Au over 16–28m widths are exceptional for an open-pittable system.
Similar exceptional intercepts were recently recorded as bonanza grades at Greenewood, demonstrating that the broader geological system possesses the right structural traps to concentrate these unusually high metal values.
For investors, the combination of near-surface depth, high-grade continuity, and thick intercepts is exactly the geometry that project economics models respond to. It means lower strip ratios, higher recovered gold per metre of ore mined, and a stronger platform for a viable scoping study.
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The bigger picture: Mainwood’s role in Marmota’s Gawler Gold strategy
A 320-hole program with 69 sections still to report
The Stage 3 drilling program is substantial in scope. Marmota has proposed 320 holes totalling approximately 31,000m, at an average hole depth of approximately 97m downhole, with drilling expected to complete in early October 2026.
Today’s release covers only sections 1 to 15 of 84 total sections. The four stated program objectives are:
- Northern extensions and depth extensions at Greenewood
- Southern extensions — identify contiguous high-grade gold in the maiden Mainwood drilling (already achieved based on sections 1–15)
- Significantly grow the mineral resource
- Increase drilling density to enable an Indicated Resource classification for the Scoping Study
Program objective 2 has already been met with this first release. Program objectives 3 and 4 are also described as being achieved even with partial data from sections 1 to 15. Program objective 1, covering northern extensions and depth at Greenewood, will be the subject of a separate forthcoming ASX release.
Expectations for that upcoming release are elevated because earlier phases of the Greenewood campaign yielded some of the best Gawler Craton gold results since 1995, establishing the high baseline the company is now trying to expand.
The volume of assay data still to come is significant. With 69 sections outstanding and drilling still active within sections 1 to 15, investors should expect a series of further announcements before the full picture emerges.
Greenewood and Mainwood within the Arc of Gold
Marmota’s Gawler Gold Project comprises what the company describes as an “Arc of Gold” running along the flanks of a major Y-shaped gravity anomaly in the NW Gawler Craton. The deposits, from east to west, are: Aurora Tank, Golf Bore, Campfire Bore, Greenewood, Mainwood, the Challenger Mine (which produced over one million ounces of gold), and Monsoon and Typhoon. Marmota owns all of the unmined gold deposits, either 100% or 90%.
Greenewood and Mainwood sit within the Golden Moon JV. Marmota holds 90% ownership via its 100%-owned subsidiary Half Moon Pty Ltd, with Coombedown Resources holding the remaining 10%. Ministerial Consent for this arrangement was granted in June 2025.
The two zones are located approximately 35km northwest of Marmota’s flagship Aurora Tank gold deposit and approximately 30km northeast of the Challenger Gold Mine. That proximity to Aurora Tank creates potential economies of scope and scale that the company has flagged as a key investment angle.
Mainwood’s history puts the significance of this program into sharp relief. Prior to Marmota’s current program, the Mainwood zone had seen only approximately 3,700m of RC drilling across 53 holes since discovery, with no drilling at all since 2018. This maiden MEU program represents a step-change in drill coverage for the zone.
Marmota’s Greenewood program is yielding some of the best gold results seen in the Gawler Craton since the discovery of the Challenger deposit in 1995. A maiden scoping study for Marmota Gawler Gold recently commenced, as announced on 18 November 2025.
With 69 sections still to report and drilling active, the full extent of the Mainwood system remains open. What sections 1 to 15 have already delivered is a connected high-grade gold zone, starting close to surface, in a previously under-drilled area with direct strategic links to the company’s broader project portfolio.
Ready to Explore the Full Scope of Marmota’s Mainwood Gold Discovery?
Marmota’s maiden Mainwood drilling has already confirmed a contiguous, near-surface high-grade gold system — and this is only the first release from sections 1 to 15 of 84 total sections, with 69 sections still to report. The combination of bonanza-grade intercepts, shallow open-pittable depths, and a 320-hole program still underway signals there is significantly more to come from the Gawler Craton.
To stay across every development as results are released, explore Marmota’s full project profile and investment case on Discovery Alert and track the unfolding story at Greenewood and Mainwood in real time.