GreenTech Metals Validates High-Grade Munni Munni Zones in Phase 1 Drilling

Phase 1 Drilling Uncovers New High-Grade Zones

GreenTech Metals (ASX:GRE) has unearthed some of the highest-grade platinum group elements (PGE3) combined with copper and nickel mineralisation at its Munni Munni Project in Western Australia. The Phase 1 drilling program, completed in March 2026, delivered standout intercepts such as 12 metres at 3.13 g/t PGE3 with 0.30% copper and 0.17% nickel from 90 metres depth, including a richer 2 metres at 8.37 g/t PGE3 with elevated base metals. These results not only confirm the lateral continuity of the Ferguson Reef but reveal thicker zones of mineralisation than previously documented, particularly in shallow reef areas.

Importantly, the drilling also identified copper and nickel sulphide mineralisation outside the high-grade PGE reef domains, a feature that had been underappreciated in historic resource models that applied a 1.9 g/t PGE cut-off. This broader mineralisation envelope opens the door to considering bulk open-cut mining methods, especially in eastern zones where mineralisation outcrops near surface.

Historic Data Validation Through Twin Holes and Core Resampling

GreenTech’s approach included drilling six twin holes to directly validate historic assay results, all of which intersected significant mineralisation consistent with earlier data. Complementing this, the company resampled 16 historic drill holes from well-preserved core stored on-site, providing a cost-effective means to verify and expand the existing database. This dual strategy reinforces confidence in the historic resource and supports the upcoming re-estimation to JORC Code 2012 standards.

The historic resource, last estimated by Helix Resources in 2002, stands at 23.6 million tonnes averaging 2.9 g/t 4E (Pt, Pd, Au, Rh) for 2.2 million ounces. GreenTech’s validation work, including QA/QC oversight by Snowden Optiro, aims to modernise this estimate by incorporating payable copper and nickel credits using a Net Smelter Return cut-off, with results expected in June 2026.

Strategic Implications and Next Steps

CEO James Rattenbury emphasised the significance of these findings, noting the potential of Munni Munni to deliver new shallow zones of high-grade PGE mineralisation alongside wider base metal sulphide zones. The results also underscore the value of the historic exploration work, providing a robust foundation for future programs.

GreenTech plans to follow up with infill and extensional drilling targeting reef thickening and continuity, alongside metallurgical testing and bulk density sampling to refine resource models and economic assessments. The company’s strategy leverages a dominant West Pilbara landholding, including the adjacent Whundo Project, to build a multi-commodity hub for critical minerals.

The Phase 1 drilling success builds on earlier efforts to consolidate the Munni Munni Project, as detailed in the company’s recent historic core resampling and resource upside and historic data review and upside potential. These efforts collectively position GreenTech to unlock the full potential of this world-class PGE-Cu-Ni system.