Great Boulder Hits 82.8g/t Gold and Extends Side Well Resource Beyond 1Moz
Great Boulder extends Side Well gold mineralisation with high-grade hits up to 82.8g/t
Great Boulder Resources has intersected further high-grade gold at its Side Well Gold Project near Meekatharra in Western Australia, extending mineralisation to the north and east of the 782,000oz Mulga Bill–Eaglehawk resource. The latest drilling returned standout intercepts including 0.64m @ 82.8g/t Au at Eaglehawk, 7m @ 14.5g/t Au from 56m, and 18m @ 7.36g/t Au from 120m at Mulga Bill. The total Side Well project resource now stands at 1.02 million ounces, with the company maintaining a steady flow of assay results across two active projects.
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Standout intersections at Mulga Bill and Eaglehawk
Extensional drilling has confirmed lode continuity and grade outside the current resource envelope at both deposits. Mulga Bill East has now been extended by more than 400m, defining high-grade gold over approximately 900m of strike. Results at Eaglehawk demonstrate that mineralisation remains open beyond the modelled resource boundaries.
| Prospect | Hole ID | Intersection | Grade (g/t Au) | From (m) |
|---|---|---|---|---|
| Mulga Bill | 26MBRC039 | 18m | 7.36 | 120m |
| Mulga Bill | 26MBRC034 | 6m | 14.8 | 265m |
| Mulga Bill | 26MBRC033 | 2m | 13.3 | 102m |
| Eaglehawk | 26EHRC032 | 7m | 14.5 | 56m |
| Eaglehawk | 26EHRCD001 | 0.64m | 82.8 | 265.36m |
| Eaglehawk | 26EHRC027 | 4m | 9.12 | 80m |
| Eaglehawk | 26EHRC026 | 8m | 4.30 | 84m |
Andrew Paterson, Managing Director
“As a result, we have extended the known mineralisation in this area by more than 400m, defining high-grade gold over a total of 900m of strike.”
Extensions outside the existing resource envelope point to growth potential in future resource updates. The combined Mulga Bill–Eaglehawk deposit now extends over 2.5km of strike, with recent drilling confirming mineralisation in the gap between the two zones.
Ironbark metallurgical drilling delivers a high-grade result
One diamond hole was completed at Ironbark to obtain core for geotechnical assessment and metallurgical sampling, marking the final hole of a programme that commenced in late 2025. Hole 26IBDD001 intersected 5.89m @ 18.1g/t Au from 122.8m. The result is consistent in tenor with other nearby high-grade RC intersections at the northern end of Ironbark, confirming continuity of the higher-grade zone at depth.
Understanding why extensional drilling matters
Extensional drilling tests whether mineralisation continues beyond the boundaries of a current resource. When explorers drill outside an existing resource envelope, they are investigating whether the mineralised system is larger than currently modelled. “Open” mineralisation — where grade persists beyond drilled limits — indicates room for the deposit to grow in a future resource update.
Strike length is the horizontal extent of a mineralised zone. At Mulga Bill East, the extension from 450m to 900m effectively doubles the known footprint of the system. High-grade intersections (double-digit grams per tonne) attract investor attention because they represent richer ore. The current Side Well resource averages 2.0g/t Au, making intercepts above 10g/t materially higher grade.
Key terms:
- Strike length: Horizontal extent of a mineralised zone along its orientation
- “Open” mineralisation: Grade continues beyond drilled limits, suggesting potential for growth
- g/t Au: Grams of gold per tonne; higher figures indicate richer ore
- Extensional vs infill drilling: Testing outward for new mineralisation versus confirming continuity within known zones
The bigger picture: 1.5 million ounces across two Murchison projects
Side Well sits within Great Boulder’s broader Murchison portfolio, which includes the recently acquired Peak Hill project. Side Well holds a total resource of 1.02 million ounces, whilst Peak Hill (proposed to be acquired) contributes a further 481,000oz.
| Project | Category | Tonnes | Grade (g/t Au) | Ounces Au |
|---|---|---|---|---|
| Side Well | Subtotal | 16,042,000 | 2.0 | 1,021,000 |
| Peak Hill | Subtotal | 9,385,000 | 1.6 | 481,000 |
| Total | All Resources | 25,427,000 | 1.8 | 1,502,000 |
The Side Well resource was announced on 18 December 2025. Peak Hill is proposed to be acquired, as detailed in the announcement on 4 May 2026.
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What comes next for Great Boulder
Great Boulder is maintaining momentum across both projects with multiple rigs in operation. The forward programme includes:
- A diamond rig operating at Golden Bracelet, whilst an AC rig tests regional targets in the Eastern corridor at Side Well.
- Two RC rigs at Peak Hill with 40,000m of drilling planned for the current half-year, targeting the Jubilee–Golden Treasure and Durack areas.
- First assay results from Peak Hill anticipated in late August 2026, according to management guidance.
A steady pipeline of assays across two projects provides ongoing catalyst potential for investors as drilling continues to test extensions and infill known zones.
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