Locksley Confirms High-Grade Rare Earth Mineralization at El Campo and Extends Dam Antimony Mineralization

SAN BERNARDINO, Calif., June 4, 2026 /PRNewswire/ -- Locksley Resources Limited (ASX: LKY, OTCQX: LKYRF) announced that assay reports from its maiden diamond drilling program at the El Campo Rare Element (REE) prospect, within the company's Mojave Prospect in California, confirmed high-grade NdPr-enriched light rare earth mineralization. The El Campo project is strategically located approximately 3.4 miles southeast of MP Materials' Mountain Pass Mine, the only operating and producing rare earth mine in the U.S.

Key highlights include:

• Neodymium (Nd) and Praseodymium (Pr) magnet rare earth oxides represent approximately 25% of TREO in key drill intercepts, highlighting enrichment in the critical rare earths elements required for permanent magnets, defense technologies, robotics and advanced manufacturing.
• Significant total REE oxide (TREO) intercepts returned from maiden drilling at El Campo include:
  • Peak value of 6.03% TREO over 0.7m in drill hole ECDD0002
  • 7.2m @ 2.93% TREO in drill hole ECDD0002, including 3.75m @4.45% TREO
  • 0.90m @ 1.09% TREO in drill hole ECDD0004

Details can be found here: https://cdn-api.markitdigital.com/apiman-gateway/ASX/asx-research/1.0/file/2924-03097136-6A1328285&v=undefined.

In addition, final results from drilling at the company's Dam Antimony Mine (DAM) successfully intersected antimony mineralization beneath historical underground workings. Antimony intersections returned from the final two of eight completed drill holes including:

• Peak value of 6.44% Sb over 0.3m in DADD0007
• 0.3m @ 2.90% Sb in hole DADD0007.

The results at El Campo are significant given the strategic importance of Nd and Pr rare earth oxides in permanent magnet supply chains, including electric vehicles, robotics, unmanned systems, defense applications and advanced manufacturing.

"Diamond drilling at the El Campo prospect represents the first test of the depth extensions of known REE mineralization exposed at surface," said Ian Stockton, Locksley Resources non-executive technical director. "The results are encouraging and consistent with observations from surface mapping and sampling. We are now evaluating the REE opportunity in the context of our evolving understanding of the Mountain magmatic system at El Campo."

With respect to the completion of the diamond drilling at DAM, he noted this represents the first test of antimony mineralization beneath the historical workings. "The final assay results confirm previously announced drilling results that high-grade antimony mineralization extends below the historic workings. In addition, these results also indicate that the mineralization extends to the south and remains open along strike and at depth," said Stockton.

Locksley Resources (https://www.locksleyresources.com.au) is focused on critical minerals in the U.S. The company is actively advancing the Mojave Project in California, targeting rare earth elements (REEs) and antimony. Locksley is executing a mine-to-market strategy for antimony, aimed at reestablishing domestic supply chains for critical materials, underpinned by strategic downstream technology partnerships with leading U.S. research institutions and industry partners. This targeted approach, combined with resource development with innovative processing and separation technologies, positions Locksley to play a role in advancing U.S. critical materials independence.

Contact: Locksley Resources Limited, Beverly Jedynak, [email protected], 312-943-1123; 773-350-5793 (cell)

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SOURCE Locksley Resources