Australian Rare Earths Drills 130m of Carbonatite Extending System 5km South

Overland carbonatite discovery grows as 130m intersection extends system 5km south

Australian Rare Earths (ASX: AR3) has materially expanded its Overland carbonatite discovery, with follow-up drilling intersecting 130 metres of carbonatite in hole OV176, located approximately 5km south of the original discovery hole OV167.

Hole OV176 intersected carbonatite from 68m depth, terminating at 201m while still within the carbonatite body. True thickness is not yet determined, and the system remains open at depth, meaning the full extent of the intersection is still unknown.

With approximately one week of drilling remaining in the current programme, results to date are reshaping the scale of what AR3 believes it has found. The emerging system is now interpreted as a large-scale carbonatite complex extending along a ~10km magnetic corridor.

Travis Beinke, Managing Director and CEO

“The results so far from this drilling program have significantly increased our confidence that Overland hosts a carbonatite system of considerable scale. The 130 metre carbonatite intersection in OV176, located approximately 5 kilometres south of our original discovery hole, significantly extends the known footprint of the system, which remains open at depth…”

What the drill holes reveal about the emerging system

Three holes were completed along the southern traverse, each contributing a distinct piece of the geological picture. Together, they allow AR3 to begin mapping the geometry of the intrusive body and tighten targeting for future drilling.

A cross-section through OV176, OV177, and OV178 (Figure 1 in the announcement) displays the interpreted carbonatite geometry alongside downhole natural gamma and pXRF niobium and barium responses. Readers should refer to Figure 1 directly for the specific Nb (ppm), Ba (ppm), and gamma (CPS) values, as these are presented visually in the source.

OV176 — the headline intersection

OV176 is the southernmost hole and the programme’s standout result. The 130m carbonatite intersection from 68m depth displays characteristic carbonatite mineralogy and texture, together with significant sulphide mineralisation and a pronounced gamma signature.

The hole terminated at 201m still within carbonatite, confirming the system is open below that depth. This is not a capped result; it is an open-ended one.

OV177 and OV178 — defining the margins

• OV177 (approximately 100m west of OV176): Recorded a stronger gamma response than OV176 but with fewer obvious carbonatite mineralogical and textural characteristics. AR3 interprets this as an alteration zone at the margins of the carbonatite intrusion, with nearby basement rocks showing evidence of carbonatite-related mineralogical modification.
• OV178 (a further ~100m step-out to the west): Returned significantly lower gamma responses and defined the western margin of the carbonatite body at this location. Lower gamma here is consistent with moving away from the magnetic high.

Together, these three holes allow AR3 to begin constraining where the carbonatite body begins and ends laterally. OV178 effectively pinpoints the western margin at this traverse, which sharpens the targeting model for future drilling considerably.

Why carbonatites matter to critical minerals investors

Carbonatites are a globally rare igneous rock type, formed from carbonate-rich magmas originating deep in the Earth’s mantle. Their rarity is precisely why the geological community pays close attention when one is found.

Here is why they matter for investors in critical minerals:

• Global significance: Carbonatites host many of the world’s most significant rare earth element (REE) and niobium deposits
• Niobium: A critical mineral used in high-strength steel alloys and battery technology
• Rare earth elements: Essential for permanent magnets in electric vehicles and wind turbines — two of the fastest-growing demand sources in the clean energy transition
• Next catalyst — assays: Samples have been dispatched to Bureau Veritas in Adelaide, with results expected in approximately 6 weeks. These assays will determine the actual grade and economic significance of the mineralisation
• pXRF results are indicative only: The announcement explicitly cautions that portable X-ray fluorescence (pXRF) readings of niobium and barium should not be treated as equivalent to laboratory assay results. The pXRF confirms the presence of mineralisation but does not accurately determine elemental concentrations due to limitations including a small analysis window, shallow penetration depth, and irregular surfaces. Laboratory assays are the definitive test

The scientific interest in this discovery adds context to its significance. Representatives from the ARC Training Centre for Future Critical Resources, the Geological Survey of South Australia, and Adelaide University recently visited the OV176 drill site to inspect core. Named researchers attending included Professor Carl Spandler, Holly Cooke, and Dr Adam Abersteiner.

This academic and government engagement reflects the rarity of carbonatite systems and their importance as potential critical mineral sources. It is scientific validation of the discovery’s geological significance, not a commercial endorsement.

What’s next — assays, drilling completion, and the 10km corridor

AR3’s immediate focus is on two confirmed catalysts: completing the current drilling programme and receiving laboratory assay results.

Key upcoming developments based on the announcement:

• Assay results: Samples dispatched to Bureau Veritas, Adelaide, with results expected in approximately 6 weeks. These will define the distribution of rare earth elements, niobium, and other critical minerals within the system
• Remaining drilling: Approximately one week of drilling remains in the current programme across additional traverses
• 10km magnetic corridor: Drilling continues to correlate with the interpreted ~10km magnetic corridor, underpinning AR3’s growing confidence in the system’s overall scale. This correlation is the structural reason the company’s confidence is expanding, not just one large intercept in isolation
• OV175 validation: This hole, at approximately 58m depth, encountered elevated gamma responses and alteration features consistent with a carbonatite source at historic target R64, further supporting magnetics as an effective exploration tool across the broader corridor
• Academic collaboration: AR3 intends to continue geological, mineralogical, and geochemical studies with its academic partners
• Further drilling: Potential RC (reverse circulation) or diamond drilling of priority targets has been identified as further work following the current programme

The announcement does not provide any implied timeline for a resource estimate, economic assessment, or production scenario, and none should be inferred at this stage. Assay results remain the next definitive step in determining the fertility and potential economic significance of what the company is describing as an emerging large-scale carbonatite system.

Beyond the carbonatite programme, AR3 has reported a uranium discovery at Overland through separate exploration work, reinforcing the project corridor’s potential as a multi-target critical mineral system.

Collar coordinates sourced from Appendix 2 of the ASX announcement dated 15 September 2026. All holes drilled vertically (dip -90°). True widths are not currently known — all intersection lengths are reported as downhole lengths.

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