Thicker Mineralisation at Tannenberg Raises Questions on Resource Scale and Development Risks

Modern Assays Reinforce Historical Data

GreenX Metals Limited has released the first tranche of modern assay results from its re-sampling of archived drill cores at the Tannenberg Copper Project in Germany. These assays, drawn from six of 47 historical drill holes dating back to the 1980s, confirm copper grades ranging from 0.7% to 2.7% over intervals between 1.0 and 3.7 metres. Notably, these results validate the accuracy of historical data while revealing mineralisation thicker than the narrow intervals previously estimated in 1940.

Expanding the Mineralisation Envelope

The new data challenge the long-held geological assumption that copper mineralisation was confined to a thin Kupferschiefer shale horizon. Instead, GreenX’s findings support an epigenetic model where mineralisation extends beyond this shale into adjacent footwall and hanging wall rock units. This is consistent with the geological setting of KGHM’s prolific Polish Kupferschiefer operations, which produce nearly 600,000 tonnes of copper annually. The thicker mineralised intervals, some up to 3.7 metres, suggest a potentially larger and more economically significant resource than previously recognised.

Robust Quality Assurance and Ongoing Exploration

GreenX’s program adheres to rigorous quality standards, with over 90% core recovery and analysis conducted by an ISO/IEC 17025 accredited laboratory. The archived core, stored for over 40 years by a German state authority, was found in excellent condition, enabling reliable modern testing. The company plans to continue re-logging, assaying, and hyperspectral scanning of the remaining cores through early 2026, alongside reprocessing historical geophysical data and digitising legacy geological records.

Strategic Acquisition and Future Outlook

Building on this progress, GreenX intends to exercise its option to acquire 90% of Group 11 Exploration GmbH, the private German company holding the Tannenberg licences, by the end of 2025. This acquisition will consolidate GreenX’s control over the project and pave the way for twin drilling to verify historical estimates and establish a JORC-compliant mineral resource. CEO Ben Stoikovich emphasised the significance of these initial results as a foundation for defining the project’s scale and importance within one of Europe’s most accessible mining districts.

Implications for European Copper Supply

As global demand for copper intensifies, particularly for clean energy technologies, the Tannenberg Project’s validation of historical data and demonstration of thicker mineralisation intervals could position GreenX as a key player in European copper supply. The project’s location within the well-established Richelsdorf Mining District and its geological parallels to major Polish deposits add strategic value. However, environmental protections within the licence area will require careful management as exploration advances.