Encounter Resources Boosts Aileron Niobium Resource by 83% Amid Expanding Copper-Gold Drilling

Aileron Niobium Resource Surges on 2025 Drilling Results

Encounter Resources has delivered a striking 83% increase in the inferred niobium Mineral Resource Estimate (MRE) at its Green deposit within the Aileron Niobium-REE project in Western Australia’s West Arunta region. The updated independent MRE now stands at 100 million tonnes grading 0.71% Nb₂O₅ (at a 0.25% cut-off), containing 19 million tonnes at a higher 1.6% Nb₂O₅ cut-off. This represents a 48% increase in contained niobium at Green compared to the initial estimate released in May 2025.

Combined with the Emily and Crean deposits, the total inferred MRE at Aileron has expanded by 54% to 120 million tonnes at 0.77% Nb₂O₅, containing 26 million tonnes at 1.7% Nb₂O₅. This scale and grade underpin ongoing pre-development activities including metallurgy, mining, environmental, geotechnical, and hydrogeological studies. The company plans to commence infill and extensional drilling in May 2026 to upgrade the resource classification and delineate high-grade starter pits.

Drilling in 2025 extended the Green deposit strike by over 2 kilometres, with standout intercepts including 85 metres at 3.1% Nb₂O₅ from 48 metres and 11 metres at 5.5% Nb₂O₅ from 74 metres. Encounter is also investigating significant fresh-rock niobium and rare earth element (REE) mineralisation outside the current oxide-focused MRE, reflecting potential upside analogous to existing global niobium mines that exploit primary carbonatite mineralisation.

This resource growth builds on the company’s earlier update that lifted the Aileron resource by over 50%, reinforcing the project's potential as a multi-decade mining operation in a critical minerals province. The drilling results and resource expansion highlight the project's momentum as Encounter advances towards development readiness. The updated MRE and drilling campaign details are consistent with the figures reported in the recent expanded Aileron niobium resource announcement.

Copper-Gold Exploration Accelerates in Paterson Province

In parallel with its niobium ambitions, Encounter is pushing forward with copper-gold exploration in Western Australia’s Paterson Province, a hotbed for large-scale deposits including the Havieron and Telfer mines. A 6,000-metre reverse circulation (RC) drill program has commenced at the Lamil Copper-Gold Project’s Elsa prospect, co-funded through an Exploration Incentive Scheme (EIS). The program targets a large-scale breccia system interpreted as a potential feeder to a Havieron-style mineralised body, located just 25 kilometres from the Telfer mine.

Historical drilling at Elsa has intersected extensive brecciated and sulphide-altered rocks, with surface geophysics revealing strong chargeable anomalies. The company has engaged Dr David Cooke, a leading expert in magmatic hydrothermal systems, to refine the geological model and vector towards mineralisation. Assay results from the ongoing RC program will inform subsequent diamond drilling designed to test for high-grade copper-gold zones.

Further copper exploration is underway at the Yeneena Copper Project, where preparations are advanced for RC and diamond drilling to follow up high-grade copper intersections at the Parbo prospect. Encounter reported an initial MRE of 2.9 million tonnes at 0.79% copper at the Tyrell copper oxide deposit within Yeneena, with multiple high-grade sulphide targets identified for drilling.

Meanwhile, the Jessica Copper Project in the Northern Territory, farmed-in by South32, is set for an extensive 2026 drilling campaign comprising 4,000 metres of RC and 2,000 metres of diamond drilling. Targets have been generated from recent VTEM, MIMDAS, and airborne electromagnetic surveys. The project area was recently expanded with a new tenement addition, and exploration will include regional magnetotelluric surveys to map major faults and conductive units. These developments align with the company’s earlier Jessica copper project drilling plans update.

Corporate Moves and Financial Position

On the corporate front, Encounter appointed mining executive Simon Hay as an independent non-executive director effective January 2026. Hay’s experience includes leadership roles at Galaxy Resources, Leo Lithium, and Iluka, bringing substantial expertise to Encounter’s board as it advances its critical minerals and base metals portfolio.

The company held approximately $31.6 million in cash at 31 March 2026, reflecting a strong balance sheet following a $25 million placement completed earlier in the year. Exploration expenditure for the quarter totalled around $2.1 million, focused primarily on Aileron and copper-gold programs in Western Australia and the Northern Territory. No mining development or production activities were conducted during the quarter, consistent with Encounter’s exploration and pre-development phase.

Changes in company secretarial roles were also noted, with Kevin Hart resigning and Dan Travers continuing as Company Secretary and CFO. The company issued 300,000 options and 100,000 performance rights during the quarter, maintaining incentives aligned with its growth objectives.

Outlook for Upcoming Activities

Looking ahead, Encounter plans a multi-rig drilling program at West Arunta targeting further resource growth and new discoveries, including infill and extensional drilling at Green and exploration of the Crean-Hurley carbonatite complex. Metallurgical test work at Aileron will continue, focusing on producing high-grade niobium concentrates and ferroniobium products.

In the Paterson Province, assay results from Lamil’s RC drilling will guide diamond drilling, while Yeneena will see diamond and RC drilling at Tyrell, Parbo, and Haddon prospects. The South32-operated Jessica project will proceed with its planned drill programs, supported by comprehensive geophysical surveys.

Encounter’s strategy also includes ongoing engagement with potential partners to accelerate exploration and development, reflecting the company’s intent to leverage its growing resource base and exploration pipeline in critical minerals and base metals.