Heavy Rare Earths Eyes High-Grade Resource Upgrade at Subron by Q4 2026
Key Takeaways
- HRE is targeting a new high-grade Mineral Resource Estimate at Subron by mid Q4 2026, upgrading from the existing 159Mt @ 870ppm TREO JORC Inferred Resource announced in October 2023.
- Ten high-grade HREO domains have been identified across 12.9km of newly mapped structural corridors, with standout intercepts including 2m @ 3,795ppm TREO at a 51% HREO ratio from hole AC361.
- The re-domaining exercise is low-cost because it draws on data from more than 550 existing historical aircore holes — no new drilling required to reach the upgraded MRE.
- Subron's identified high-grade domains carry HREO ratios above 38%, materially higher than the global norm of low-single-digit to low-teens percentages.
- Critical minerals re-assay results for gallium and hafnium are expected shortly, with SEM/TIMA mineralogical analysis and metallurgical sighter testwork also in the near-term pipeline.
Subron rare earths project targets high-grade HREO resource upgrade by Q4 2026
Heavy Rare Earths Limited (ASX: HRE) is advancing a re-domaining exercise at its Subron Rare Earths Project in south-central Western Australia, targeting a new, smaller-tonnage but substantially higher-value Mineral Resource Estimate (MRE) by Q4 2026. The existing resource stands at 159Mt @ 870ppm TREO as a JORC Inferred Resource announced on 3 October 2023, and the upgrade pathway is designed to be low-cost because the majority of data required already exists across more than 550 historical aircore holes. Three concurrent work streams are now underway: database re-domaining, SEM/TIMA mineralogical analysis, and re-assaying of historical sample pulps for critical minerals including gallium (Ga) and hafnium (Hf).
Jason Barnett, Managing Director and CEO
“The Subron Rare Earths Project is the standout story for HRE this quarter… this is a rapid low-cost route to materially upgrade the quality of what we report to the market.”
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What makes Subron’s heavy rare earth ratios stand out
Not all rare earths are equal. Light rare earth oxides (LREO) are far more abundant globally, while heavy rare earth oxides (HREO) are scarcer, command higher prices, and sit at the centre of defence and advanced manufacturing supply chains where supply outside China is acutely limited. The HREO ratio measures what percentage of a deposit’s total rare earth oxide (TREO) content is made up of the more valuable heavy elements — and most deposits globally sit in the low-single-digit to low-teens range. Subron’s identified domains, including the standout Seawolf prospect, carry HREO ratios well above 38% of contained TREO, which is materially higher than the global norm.
The Seawolf prospect sits at the heart of HRE’s high-grade HREO story, with mineralisation geometry and ratio characteristics that informed the structural corridor mapping now central to the re-domaining exercise.
The ten high-grade domains identified across 12.9km of structural corridors
A strategic review identified 10 high-grade HREO domains across 12.9km of newly mapped structural corridors within the existing resource footprint. Selected headline intercepts from the data illustrate the quality of mineralisation:
- AC361: 2m @ 3,795ppm TREO, 1,918ppm HREO at a 51% HREO ratio, from 24m
- AC363: 2m @ 3,611ppm TREO, 1,751ppm HREO at a 48% HREO ratio, from 36m
- AC360 (best composite): 8m @ 3,057ppm TREO, 1,344ppm HREO at a 42% HREO ratio, from 27m
- AC225: Multiple consecutive intervals with TREO values up to 7,222ppm and a peak HREO ratio of 37%
| Hole ID | From (m) | Interval (m) | TREO (ppm) | HREO ratio (%) |
|---|---|---|---|---|
| AC361 | 24 | 2 | 3,795 | 51% |
| AC363 | 36 | 2 | 3,611 | 48% |
| AC360 | 27 | 8 (composite) | 3,057 | 42% |
| AC225 | 26 | 2 | 7,222 | 25% |
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A fast, inexpensive pathway to a materially upgraded resource
The re-domaining methodology is straightforward in principle: rather than conducting new drilling, HRE is re-interrogating its existing database through the lens of current heavy rare earth pricing to isolate the highest-value, highest-concentration zones. Because the assay results, geological logging, and structural interpretation from more than 550 historical aircore holes are already in hand, this represents a comparatively fast and inexpensive route to a materially upgraded mineral resource statement.
The Subron project expansion achieved a 268% growth in the project’s footprint for under $30,000, establishing the large tenement package that now hosts the 550-plus historical aircore holes underpinning the current re-domaining exercise.
In parallel, high-HREO intervals returning greater than 38% HREO have been submitted for Scanning Electron Microscopy (SEM) paired with TESCAN Integrated Mineral Analyser (TIMA) analysis. This mineralogical work aims to identify the specific minerals hosting the rare earths, which is a key input into determining the most viable processing route for the deposit. Separately, intervals identified above a 200ppm HREO cut-off are being submitted for multi-element MMA analysis.
HRE is also re-assaying historical sample pulps to test for additional critical minerals including gallium and hafnium, with the first batch of results expected shortly. This work could add further value and processing optionality to the Subron project. A full stocktake of Subron sample material held at HRE’s Osborne Park storage facility is nearing completion, positioning the company for the upcoming metallurgical sighter testwork programme.
Funded and on track — what comes next
Following a recent capital raise and rights issue, Managing Director and CEO Jason Barnett stated the company is “well funded.” The new high-HREO Mineral Resource Estimate is targeted for release by mid Q4 2026. Key near-term milestones in sequence are:
- Critical minerals re-assay results (gallium, hafnium) — first batch expected shortly
- SEM and TIMA mineralogical analysis results
- Updated MRE release targeted for mid Q4 2026
- Metallurgical sighter testwork programme to come
Ready to Explore the Subron Rare Earths Project’s High-Grade HREO Upgrade Story?
Heavy Rare Earths Limited is targeting a significantly upgraded Mineral Resource Estimate at Subron by Q4 2026, leveraging over 550 existing aircore holes to isolate domains carrying HREO ratios well above the global norm — at a fraction of the cost of new drilling. With 10 high-grade domains identified across 12.9km of structural corridors and critical minerals re-assay results imminent, the project’s near-term newsflow could be substantial.
Dig deeper into the data, milestones, and investment case by visiting the Heavy Rare Earths investor profile on Discovery Alert, where the full project background and upcoming catalysts are laid out in detail.