GreenX Metals has unveiled a substantial Exploration Target at its Tannenberg Copper Project in Germany, estimating up to 279 million tonnes of mineralisation with significant copper and silver grades. This marks a strategic shift to active exploration following extensive archival research.
- Exploration Target estimates 144–279 Mt at 0.9%–1.4% Cu and 15–21 g/t Ag
- Target includes hanging wall and footwall mineralisation beyond historical focus
- Validation from Polish Kupferschiefer mining analogues
- Transition from archival data synthesis to drilling and metallurgical testing
- Incentive options linked to JORC inferred resource milestone
Exploration Target Signals Potential for Major Copper-Silver Deposit
GreenX Metals (ASX:GRX) has lifted the veil on a large-scale Exploration Target at its Tannenberg Copper Project in Hessen, Germany, estimating between 144 and 279 million tonnes of mineralisation grading 0.9% to 1.4% copper and 15 to 21 grams per tonne silver. This equates to a potential 1.3 to 3.9 million tonnes of contained copper and 69 to 188 million ounces of silver, numbers that place Tannenberg firmly in the league of globally significant copper deposits.
Unlike the 1940 historical estimate that narrowly focused on the Kupferschiefer shale horizon, GreenX's target ambitiously captures mineralisation in the hanging wall limestone and footwall sandstone units. This modern interpretation aligns with the operational reality at KGHM Polska Miedź S.A's mines in Poland, where up to 95% of mineable copper is hosted in these adjacent units, underscoring the potential scale of Tannenberg's resources.
Historical Data Underpins Modern Geological Model
The Exploration Target emerges from an 18-month deep dive into archival data, including the digitisation of the 1930s National Socialist drilling campaign and the 1980s St Joe Explorations dataset. GreenX has meticulously re-logged and sampled over 4,300 metres of archived drill core, collecting more than 2,300 new assays to validate and expand upon historical findings.
While the 1940 estimate reported 728,000 tonnes of contained copper within a narrow shale layer, the 1984 St Joe work first hinted at thicker, economically viable mineralisation extending beyond the shale. GreenX's recent work, including resampling of archived core, confirms mineralised thicknesses between 1.7 and 3.3 metres, substantially wider than the original 20–60 cm shale focus, and supports grades averaging 1.28% copper and 19.4 g/t silver.
This comprehensive dataset formed the basis for a geological model constructed in Leapfrog Geo, incorporating fault structures and stratigraphic units to delineate three mineralised zones covering approximately 43 square kilometres. The model applies a 0.3% copper cut-off and a minimum thickness of 1.5 metres, generating tonnage estimates between 144 and 279 million tonnes and contained copper ranging from 1.3 to 3.9 million tonnes.
From Archive to Active Exploration
GreenX is pivoting from archival synthesis to active fieldwork. The company plans to undertake metallurgical test work on material sourced from historical underground mines, commence seismic surveys to refine drilling targets, and launch an initial drill program in late 2026. These steps aim to validate the Exploration Target and advance towards a JORC-compliant Mineral Resource estimate.
To align management incentives with project milestones, GreenX proposes issuing options that vest only upon public announcement of an independently assessed JORC inferred resource containing at least 1.5 million tonnes of contained copper equivalent at a minimum 1% grade.
GreenX's CEO Ben Stoikovich noted, "The modern understanding of the Kupferschiefer system, demonstrated by the scale of mining operations in Poland, justifies continued investment and exploration at Tannenberg." This reflects a strategic commitment to unlocking the project's full potential beyond the historical lens.
Environmental and Regulatory Considerations
The Tannenberg licences, awarded in mid-2025, cover areas with various environmental protections including Natura 2000 habitats and nature reserves. GreenX's due diligence suggests these do not preclude exploration or eventual mining, provided operations comply with applicable standards. The company is also digitising historical geological and production data to support ongoing evaluation.
GreenX's Exploration Target announcement builds on its recent validation of historical copper grades and successful capital raises, including a A$13.6 million placement earlier this year to fund exploration and development activities. This financial backing provides a runway for the upcoming drilling and test work phases, which will be critical in moving Tannenberg from conceptual potential to defined resource.
Given the project's location in a historically mined district and the extensive archival data now integrated into modern models, the upcoming exploration campaign could reshape perceptions of Germany's copper potential. The company's methodical approach, combining historical insight with contemporary techniques, positions it to navigate both technical and regulatory challenges ahead.
While the Exploration Target remains conceptual with no Mineral Resource yet declared, the scale and quality of the data underpinning it warrant close attention. The transition to active exploration will be a pivotal phase, with metallurgical results, seismic surveys, and drilling outcomes set to significantly influence the project's trajectory and GreenX's market standing.
Investors following GreenX's progress may recall the company's recent efforts to validate historical copper grades at Tannenberg and secure substantial funding to accelerate growth, as seen in its successful A$13.6 million placement and validation of historic copper grades. These developments underscore a broader strategy to leverage legacy data into actionable exploration targets.
Bottom Line?
GreenX’s large-scale Exploration Target at Tannenberg sets the stage for a crucial drill campaign later this year, but the path to a JORC resource remains contingent on upcoming metallurgical and seismic results.
Questions in the middle?
- Will metallurgical test work confirm the economic viability of mineralisation beyond the Kupferschiefer shale?
- How will environmental protections within the licence area influence permitting and development timelines?
- Can GreenX translate the extensive archival data and modern geological models into a JORC-compliant Mineral Resource in 2026?