AR3 Uncovers New Niobium-Rare Earth Carbonatite at Overland Project

Discovery of Carbonatite System Expands AR3’s Critical Minerals Portfolio

Australian Rare Earths Limited (ASX:AR3) has unveiled a significant early-stage discovery at its 100%-owned Overland Project in South Australia: a niobium-rare earth carbonatite mineral system identified in drill hole OV167. The intersection spans 19 metres from 86 metres downhole, returning 0.61% total rare earth oxides (TREO) with notable concentrations of niobium (Nb2O5), neodymium, praseodymium, dysprosium, and terbium. This discovery broadens AR3’s critical minerals exposure beyond its flagship Koppamurra Rare Earths Project and uranium targets at Overland.

The mineralised zone remains open at depth, with OV167 ending in anomalous basement-hosted mineralisation. The hole was drilled above a large coherent magnetic anomaly, interpreted as a potential iron-titanium oxide accumulation within basement rocks, which the company believes may represent a sill or dyke expression peripheral to a larger, untested carbonatite intrusive system. This magnetic feature now stands as a prime target for follow-up drilling.

Petrographic Confirmation and Geochemical Signature

Detailed petrographic and scanning electron microscope (SEM) analyses confirmed the presence of pyrochlore, the principal niobium ore mineral globally, within the mineralised interval. Alongside elevated titanium, iron, barium, and thorium, these findings support the interpretation of a carbonatite-related mineral system. Carbonatites are globally recognised hosts for rare earth elements (REEs) and niobium, often forming as plugs, dykes, sills, or breccias within alkaline igneous complexes.

The geochemical signature of OV167 aligns with distal carbonatitic-fluid domains, where late-stage hydrothermal fluids precipitate niobium and rare earths along structural conduits. This style of mineralisation is consistent with globally significant deposits such as Mt Weld in Western Australia and the world’s major niobium mines.

Exploration Strategy and Next Steps

While the results stem from a single drill hole and no Mineral Resource has yet been defined, AR3 is moving swiftly to refine its exploration model. Planned activities include expanded geophysical modelling; incorporating gravity gradiometry and magnetics; detailed petrographic and mineralogical assessments, and targeted diamond and reverse circulation drilling to delineate the geometry of the sill or dyke and test for a larger carbonatite system nearby.

Managing Director Travis Beinke emphasised the discovery’s potential, noting that the multi-element niobium–rare earth–titanium signature and magnetic anomaly provide a significant new critical minerals opportunity within the Overland tenure. Nevertheless, he reaffirmed that AR3’s primary focus remains on advancing the Koppamurra Rare Earths Project toward commercialisation, with this discovery adding valuable exploration upside without diverting resources.

Broader Implications for AR3’s Portfolio

The Overland Project has historically targeted sedimentary-hosted uranium, with AR3’s recent drilling program primarily focused on uranium exploration. The discovery of a carbonatite system hosting both niobium and rare earths reveals a new dimension to the project’s potential, leveraging the company’s extensive ~8,000 km² landholding in South Australia. This complements AR3’s ongoing efforts at Koppamurra, where the company recently announced a maiden Ore Reserve with robust economics and government backing.

As the critical minerals market tightens globally, discoveries like this could position AR3 to play a more diverse role in supplying key inputs for clean energy technologies. The company’s methodical approach; integrating geophysical data, mineralogical studies, and targeted drilling; will be crucial in assessing the scale and economic viability of this carbonatite system.