Rumble Resources Ltd
Bonanza Gold Grades Point to New Potential at Rumble Resources' Munarra Gully Project
Rumble Resources (ASX: RTR) has reported one of its strongest exploration results to date, with Rumble Resources Munarra Gully bonanza gold grades drilling results confirming 13 metres at 21.64 g/t gold from 122 metres, including 5 metres at 55.56 g/t gold and a single metre grading 221 g/t gold. The result, announced on 20 July 2026, follows a reinterpretation of historical exploration data that identified large, previously undertested sections of the Amaryllis Shear Zone, with subsequent targeted drilling confirming the presence of high-grade mineralisation.
"Our exploration team has done an outstanding job to target a highly prospective area and get these bonanza gold grades of 13 metres at 21.64 grams per tonne of gold including 5 metres at 55.56 grams per tonne and 1 metre of 221 grams per tonne. There were also other holes that intersected both gold and copper so we could be onto something here. More drilling is planned at Munarra Gully in the not-too-distant future," said Peter Harold, Managing Director and CEO of Rumble Resources.
The announcement marks a notable shift in status for a project that had been largely dormant since 2021. With fresh-rock intersections now indicating structural continuity alongside gold and copper credits, Munarra Gully has moved from a background asset to a priority exploration target within Rumble's portfolio.
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What the Drilling Programme Delivered
According to the announcement, the April–May 2026 programme comprised 28 air core holes totalling 1,933 metres and 12 reverse circulation (RC) holes totalling 1,715 metres, for a combined 3,648 metres across six sections along the Amaryllis Shear Zone. RC drilling covered approximately 2 kilometres of the 2.6 kilometre mineralised strike length identified to date, with all RC drilling conducted on Rumble's 100%-owned tenement E51/1919.
Headline Gold Intercepts
| Hole ID | From (m) | Width (m) | Au Grade (g/t) | Notable Sub-Interval |
|---|---|---|---|---|
| MGRC26011 | 122 | 13 | 21.64 | 5m @ 55.56 g/t Au; 1m @ 221 g/t Au |
| MGRC26012 | 65 | 7 | 3.86 | incl. 1m @ 26.10 g/t Au |
| MGRC26007 | 132 | 7 | 2.15 | Fresh rock intercept beneath historical holes |
| MGRC26006 | 149 | 1 | 5.86 | Concurrent copper credits |
| MGRC26010 | 77 | 7 | 0.67 | Intersected in depleted saprolite zone |
Concurrent Copper Intercepts
| Hole ID | From (m) | Width (m) | Cu Grade (%) | Notable Sub-Interval |
|---|---|---|---|---|
| MGRC26011 | 128 | 7 | 0.52 | – |
| MGRC26007 | 131 | 10 | 0.39 | incl. 4m @ 0.62% Cu |
| MGRC26006 | 140 | 6 | 0.39 | incl. 1m @ 1.54% Cu |
| MGRC26012 | 121 | 4 | 0.31 | – |
The gold and copper mineralisation appears broadly co-spatial across several holes, supporting the polymetallic character of the system and the potential for copper credits to complement any future gold resource base.
Why the Reinterpretation Changed the Picture
The value of these results stems not only from the drilling itself but from the geological review that preceded it. Rumble's exploration team identified that historical drilling along the Amaryllis Shear Zone had largely failed to reach fresh rock, meaning much of the earlier work provided an unreliable basis for targeting the primary mineralised zone.
Two factors were found to have limited the effectiveness of historical drilling:
- Incomplete penetration – many historical holes stopped within the weathered surface profile, never reaching the fresh rock boundary where primary gold-copper mineralisation is hosted.
- Supergene depletion – gold dispersion patterns in the upper weathered zone were found to be inconsistent and locally depleted, meaning surface geochemistry had proven an unreliable guide to underlying mineralisation.
Based on this reinterpretation, the 2026 programme was designed with two specific objectives: extending below historical holes that had not reached fresh rock, and infilling large untested gaps along the known mineralised structure. Hole MGRC26011, the standout result, was drilled into a 300-metre gap in effective previous drilling and returned the only fresh intercept through the shear zone on that section, along with the highest-grade result reported at the project to date.
Understanding Orogenic Gold Shear Zones
For investors less familiar with this style of deposit, the following section outlines the key geological concepts relevant to Munarra Gully.
An orogenic gold shear zone, also referred to as a mesothermal gold deposit, forms when gold-bearing hot fluids move through major fault or shear structures deep in the Earth's crust during periods of tectonic activity. As these fluids cool and react with surrounding rock, gold and associated metals are deposited and concentrated within the shear zone.
Why Does This Matter for Investors?
Orogenic gold shear zones are among the more productive gold deposit styles globally and often display continuity along strike and at depth, meaning a successful intercept in one location can support follow-up drilling along the same structure. The Amaryllis Shear Zone at Munarra Gully has a currently defined strike length of 2.6 kilometres, which remains open in all directions, according to the company, suggesting further exploration upside has yet to be tested.
The shear zone's sub-vertical geometry, dipping at approximately 75 degrees, combined with typical mineralised widths of 20 to 50 metres, are characteristics the company notes as consistent with deposits of scale.
Glossary of Key Terms
| Term | Definition |
|---|---|
| Saprolite | Deeply weathered rock near the surface; gold within it may be redistributed or depleted relative to primary rock |
| Fresh rock | Unweathered bedrock beneath the weathering profile, where primary mineralisation is preserved |
| Supergene | Secondary enrichment or depletion of metals caused by weathering processes near the surface |
| Shear zone | A planar zone of deformation where rocks have been fractured and altered, often acting as a pathway for mineralising fluids |
| g/t Au | Grams of gold per tonne of rock, the standard measure of gold grade |
| RC drilling | Reverse circulation drilling, a technique that returns rock chips to surface for sampling |
| Orogenic gold | Gold deposited by hot fluids during major geological deformation events |
| Chalcopyrite | A copper-iron sulphide mineral, the primary ore mineral for copper at Amaryllis |
Comparing 2026 Results to Historical Drilling
The 2026 programme has materially built on historical results at the Amaryllis Shear Zone, both in terms of grade and interpretive reliability. Previously reported intercepts from earlier campaigns, as referenced in the announcement, included:
| Historical Result | Commodity Focus | Hole |
|---|---|---|
| 5m @ 11.67 g/t Au | Gold | AMRC008 |
| 2m @ 13.45 g/t Au | Gold | AMRC012 |
| 8m @ 1.94 g/t Au, 0.68% Cu, 9.5 g/t Ag | Gold-Copper-Silver | AMRC007 |
| 8m @ 1.11% Cu, 0.88 g/t Au, 11.8 g/t Ag | Copper-Gold-Silver | AMRC003 |
While these historical results demonstrated the presence of gold and copper mineralisation, they were constrained by weathering effects and incomplete penetration into fresh rock. Furthermore, the 2026 result of 13m at 21.64 g/t gold, including 1m at 221 g/t gold, represents a marked improvement in the quality of assay data returned from the system now that the revised geological model has been applied.
What Comes Next: Planned Path Toward Resource Definition
Rumble has outlined a follow-up programme intended to build on this drilling campaign, according to the announcement.
Near-Term Planned Activities
- Diamond twin hole of MGRC26011 – a diamond core hole is planned to twin the standout RC intercept, intended to help determine the orientation of high-grade veining within the mineralised system and support future resource drilling.
- Step-out RC drilling – follow-up RC holes are planned along strike and at depth from MGRC26011 to help define the spatial extent of the high-grade zone.
- Maiden Mineral Resource Estimate – the company has stated its intention to fast-track the definition of a maiden Gold-Copper Mineral Resource Estimate (MRE) at the Amaryllis Prospect following the next phase of drilling.
Upcoming Milestones
| Milestone | Status |
|---|---|
| Diamond twin hole of MGRC26011 | Planning underway |
| Step-out RC drilling programme | Planning underway |
| Maiden Au-Cu Mineral Resource Estimate | Targeted following next drill programme |
The sequence from high-grade drill result to maiden resource estimate is a recognised value-creation pathway in junior exploration. For a prospect with 2.6 kilometres of defined mineralised strike remaining open in all directions, the scope for resource definition could be considerable, subject to the outcome of further drilling.
The Investment Case: A Reactivated Asset with High-Grade Results
Munarra Gully has formed part of Rumble's portfolio since 2018 but had not previously delivered results of this calibre. The 2026 programme has, however, materially altered that position.
Key Investment Considerations
- High-grade gold confirmed in fresh rock: a result of 13m at 21.64 g/t gold, including 1m at 221 g/t gold, is considered exceptional and supports the potential for high-grade mineralisation within a structurally coherent shear zone system.
- Polymetallic upside: concurrent copper intercepts across multiple holes indicate gold and copper credits are broadly co-spatial, adding commodity diversification to any future resource.
- Large, undertested system: the Amaryllis Shear Zone has 2.6 kilometres of defined mineralised strike remaining open in all directions, with the reinterpretation of historical data suggesting significant sections remain effectively untested.
- 100% ownership of primary tenement: Rumble holds a 100% interest in tenement E51/1919, where all RC drilling was conducted, providing full economic exposure to any resource discovery on that ground.
- Exploration team track record: the reinterpretation that led to this result reflects the geological capability within Rumble's team, which the company notes was also responsible for its Earaheedy zinc-lead-silver discovery.
- Additional portfolio assets: Rumble's broader asset base includes the Western Queen Gold-Tungsten Project, which the company states it is developing toward near-term cash flow from existing underground resources.
Project Snapshot
| Parameter | Detail |
|---|---|
| Project Name | Munarra Gully Gold-Copper Project |
| Location | 50km north-northeast of Cue, Western Australia |
| Strike Length (Amaryllis) | 2.6km, open in all directions |
| Tenement Area | 123km² across three tenements |
| Ownership | 100% (E51/1919 and E51/1927); 80% (E51/1677) |
| Best 2026 Result | 13m @ 21.64 g/t Au, incl. 5m @ 55.56 g/t Au |
| Deposit Style | Orogenic gold shear zone (mesothermal) |
| Key Metals | Gold, copper, silver |
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Why Investors May Keep Watching Rumble Resources
Munarra Gully had been, in Harold's own words, "a bit of a sleeper." That description appears considerably less applicable following this result. A geological reinterpretation followed by targeted drilling has returned the highest-grade result reported at the project to date, from a section of the drill coverage that earlier explorers had effectively overlooked.
The combination of high-grade gold, copper credits, a large and only partially tested structural corridor, and a defined follow-up programme point to a period of ongoing news flow for the company. Consequently, with diamond and RC drilling being planned and a maiden resource estimate targeted following further drilling, several catalysts remain ahead that could help further define the scale of the Amaryllis system.
The Rumble Resources Munarra Gully bonanza gold grades drilling results have, in essence, transformed a dormant project into one of the company's most closely watched assets. With a 2.6km mineralised shear zone remaining open in all directions and a follow-up diamond and RC programme being planned, investors have clear near-term catalysts to monitor as the company works toward a maiden Gold-Copper Mineral Resource Estimate at the Amaryllis Prospect.
Ready to Dig Deeper Into Rumble Resources' High-Grade Gold Discovery?
Rumble Resources (ASX: RTR) has just transformed one of its dormant assets into a priority exploration target, with bonanza gold grades, a large and only partially tested shear zone, and a clear pathway toward a maiden Gold-Copper Mineral Resource Estimate at Munarra Gully. For investors looking to understand the full scope of what this discovery could mean — including the upcoming diamond twin hole, step-out RC drilling, and the broader Rumble portfolio — visit the company's website to access the latest announcements, project details, and investor information directly from the source.
