Magnum Mining Eyes November 2026 Resource as Plateau Zone Rare Earth Data Builds
Key Takeaways
- The 10,000m auger programme at Piracanjuba North is now complete, removing a key operational variable and leaving 521 holes with assays still pending.
- The Plateau Zone dataset now covers 200 qualifying holes with a length-weighted average of 160 ppm D-TREO — sitting above both the batch average and the whole-population average of 127 ppm across 338 qualifying holes.
- Magnet rare earth oxides (MREO) rise from 23.7% of head TREO to 33.1% of D-TREO across the 200 qualifying Plateau holes, a consistent enrichment pattern repeated in 194 of 200 holes.
- MRE samples have already been submitted to the laboratory, reducing one timing risk on the path to the November 2026 maiden JORC Mineral Resource Estimate.
- The planned 2,000m diamond infill programme is designed to build geological confidence beyond the initial MRE, not to add holes to it — the resource definition dataset is already locked.
New assays sharpen the Plateau Zone picture at Piracanjuba North
Magnum Mining and Exploration Limited (ASX: MGU) has reported assay results from a further 65 auger holes at its Piracanjuba North Project, bringing the total number of holes with reported assays to 373 of the 894 drilled. A further 521 holes remain pending.
The 10,000m auger programme is now complete, a meaningful programme milestone. Of the 65 newly reported holes, 29 fall within the approximately 32.5 km² Plateau Zone, the priority area defined for the planned maiden JORC Mineral Resource Estimate (MRE), which is targeted for the end of November 2026.
For investors, this combination matters. Programme completion removes a key operational variable, and the November 2026 MRE target gives you a defined, near-term de-risking catalyst to track.
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Why desorbable grade — not head grade — is the real signal
Piracanjuba North is an ionic adsorption clay (IAC) deposit. In an IAC deposit, rare earths sit loosely on the surface of clay particles and a portion can be released by washing the clay with a mild salt solution. This means total rare earth content and recoverable rare earth content are not the same thing.
Total rare earth oxide (TREO) measures the combined rare earth content of a sample in parts per million (ppm). Desorbable total rare earth oxide (D-TREO) measures the portion actually released in a standard laboratory screening test. The desorption rate is D-TREO expressed as a percentage of TREO. A high TREO does not guarantee a high D-TREO — and the gap can be enormous.
The clearest illustration in this batch: PIR-AH-0315 returned 1,904 ppm TREO but released only 16 ppm D-TREO (a desorption rate of 0.9%). PIR-AH-0339, with a far lower 385 ppm TREO, released 176 ppm D-TREO (46%). Of the ten holes with the highest head grade in this batch, only two appear in the ten with the highest D-TREO. Magnum ranks holes on D-TREO, not TREO — this is the company’s stated methodology.
The desorption numbers across early holes at Piracanjuba North were the first signal that D-TREO rather than TREO would be the defining metric for this deposit, with 100% hit rates and wide desorption variability prompting the company to anchor its ranking methodology firmly on recoverable content.
The magnet rare earth advantage
Magnet rare earth oxides (MREO) comprise praseodymium, neodymium, terbium, and dysprosium — the elements used in permanent magnets for electric vehicle motors and wind turbines, and the primary value drivers in a rare earth basket.
Across the 200 qualifying Plateau holes, MREO rises from 23.7% of head TREO to 33.1% of D-TREO. This enrichment occurs because cerium, a lower-value rare earth, largely stays on the clay during desorption, concentrating the magnet elements in the released fraction. The pattern is consistent: the magnet share is higher in the desorbable fraction in 194 of the 200 qualifying Plateau holes. This is not an isolated result — it reflects the expected behaviour of IAC deposits and is repeating systematically across the dataset.
The four holes with the highest whole-hole D-TREO in this batch are set out below. Note that PIR-AH-0346 and PIR-AH-0344 are classified as REGIONAL N targets, not Plateau. D-TREO values are laboratory screening results and are not process recovery.
| Hole ID | Interval | TREO (ppm) | D-TREO (ppm / %) | D-MREO (ppm / %) |
|---|---|---|---|---|
| PIR-AH-0346 (Regional N) | 12m from 0m | 1,098 | 203 (18%) | 78 (31%) |
| PIR-AH-0346 — best interval | 2m from 2m | 1,394 | 506 (36%) | 214 (72%) |
| PIR-AH-0339 (Plateau) | 15m from 0m | 385 | 176 (46%) | 50 (61%) |
| PIR-AH-0339 — best interval | 2m from 10m | 590 | 471 (80%) | 132 (91%) |
| PIR-AH-0344 (Regional N) | 12m from 0m | 497 | 161 (32%) | 52 (42%) |
| PIR-AH-0344 — best interval | 2m from 10m | 778 | 283 (36%) | 88 (43%) |
| PIR-AH-0340 (Plateau) | 15m from 0m | 963 | 153 (16%) | 58 (30%) |
| PIR-AH-0340 — best interval | 1m from 14m | 1,657 | 443 (27%) | 170 (42%) |
Managing Director Antonio Vitor
“These results continue to sharpen our understanding of Piracanjuba North and reinforce the Plateau as the priority area for resource definition. Importantly, the growing dataset shows that head grade alone does not determine the strength of an IAC response…”
Population-level dataset builds confidence across the Plateau
The announcement includes a population summary table comparing this batch against all reported holes and the Plateau Zone specifically, using paired saprolite assay and desorption intervals throughout for direct comparability.
The Plateau Zone population covers:
- 200 qualifying holes (of 221 in the zone)
- 1,385m of saprolite sampled
- Length-weighted average of 160 ppm D-TREO
- MREO rising from 23.7% of head TREO to 33.1% of D-TREO
Across the 65 newly reported holes, whole-hole D-TREO ranges from 0.85 ppm (PIR-AH-0202) to 202.59 ppm (PIR-AH-0346). The highest single-interval result is 515.41 ppm D-TREO over 2m from 10m in PIR-AH-0333. These figures are laboratory screening results and are not process recovery — D-TREO values must be read together with TREO, geology, and interval thickness.
The broader population comparison across all 338 qualifying holes reported to date shows a length-weighted D-TREO average of 127 ppm, with MREO making up 23.4% of head TREO and 32.6% of D-TREO. The Plateau Zone sits above both the batch average and the whole-population average on D-TREO, reinforcing why it is the focus of resource definition work.
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Diamond infill drilling and the path to a maiden resource
The samples intended to support the planned maiden MRE have already been submitted to the laboratory. The planned 2,000m diamond infill programme is therefore not intended to add holes to the initial MRE dataset.
Its purpose is to build geological confidence and prepare for work beyond the initial MRE. Magnum’s stated next steps are to:
- Complete outstanding assays, reconcile laboratory certificates, and freeze the database used for the MRE
- Finalise and commence the 2,000m diamond infill drilling programme in the Plateau Zone’s high-response corridors, using tighter spacing to improve confidence between holes
- Use the water-free diamond drilling configuration to improve geological control, collect density measurements and representative samples, and test the full weathering profile where auger depth is limiting
- Advance mineralogy and clay characterisation, desorption and metallurgical testwork on representative samples, and NORM assessment of process solutions, products and residues
- Progress the planned maiden JORC Mineral Resource Estimate, targeted for the end of November 2026, subject to assay timing, technical outcomes, QAQC sign-off, and completion of required resource-readiness work
The growing dataset is enabling the company to distinguish total REE content from desorbable REE content, and to focus resource definition and metallurgical work on the corridors where the desorption response is strongest. For investors, the November 2026 MRE represents the next major binary event — and the fact that MRE samples are already at the laboratory reduces one timing risk in that path.
For investors wanting to understand the scale context behind the upcoming resource estimate, our full explainer on the Piracanjuba North exploration target covers the 700-1,200Mt tonnage range, the geological assumptions underpinning it, and what the step from exploration target to JORC MRE typically requires.
Ready to Track the Path to Magnum Mining’s Maiden JORC Resource at Piracanjuba North?
With the 10,000m auger programme now complete and MRE samples already submitted to the laboratory, Magnum Mining (ASX: MGU) is advancing toward a defined November 2026 maiden JORC Mineral Resource Estimate — a clear, near-term de-risking catalyst for investors to watch. The growing Plateau Zone dataset, covering 200 qualifying holes with a length-weighted average of 160 ppm D-TREO and consistent magnet rare earth enrichment in the desorbable fraction, is steadily building the foundation for resource definition.
To understand the scale context behind the upcoming estimate, including the 700–1,200Mt exploration target tonnage range and what the step to a maiden JORC MRE typically requires, explore the full Piracanjuba North project explainer on Discovery Alert. This breakdown covers the geological assumptions, the D-TREO methodology, and the key milestones on the path to resource definition.