Polymetals Advances High-Grade Silver-Lead-Zinc Drilling at Endeavor Mine

Broad High-Grade Mineralisation Confirmed

Polymetals Resources Ltd (ASX:POL) has delivered another batch of robust assay results from its ongoing underground diamond drilling at the Endeavor Mine’s upper Main Lode in Cobar, NSW. The latest holes continue to outline broad zones of high-grade silver, lead and zinc mineralisation, with standout intercepts including 42.8 metres at 358 g/t silver, 8.3% zinc and 4.7% lead (hole POL022A) and 39 metres at 502 g/t silver, 6.9% zinc and 5.4% lead (POL025). These results reinforce the remarkable consistency of the drilling program and bolster confidence in the continuity of the remnant sulphide mineralisation surrounding the historic 1996 subsidence zone.

Refining the Mineralised System’s Architecture

The drilling is not only confirming high grades but also providing new geological insights into the upper Main Lode’s structure. Polymetals is mapping metal zonation within the weathered, oxidised and supergene portions above the principal sulphide zone. While these oxidised intervals generally carry lower grades than the sulphides, they reveal pronounced lead enrichment and help define the geometry and distribution of mineralisation. This understanding is crucial for distinguishing between mineralisation preserved after the subsidence event and remnants from historical mining by Pasminco.

Smaller Subsidence Zone Preserves Value

Earlier drilling phases established that the 1996 subsidence zone at Endeavor is materially smaller than previously interpreted, meaning significant high-grade mineralisation remains intact adjacent to existing underground workings. This reinterpretation has been validated by the continuity of mineralised intercepts across multiple drillholes, transforming the program from a proof-of-concept into a resource definition phase. The current drilling campaign is further delineating the limits of this remnant mineralisation and its upward continuation, which is key to expanding the mine’s inventory.

Advancing Toward a Resource Estimate

Geological and mineral resource modelling is progressing rapidly, with the company targeting an initial Mineral Resource estimate for the upper Main Lode later in 2026. The integration of new drilling data with historical mine records and underground surveys is refining the geological interpretation and metal zonation models. Polymetals Executive Director Jess Oram highlighted that this growing geological understanding is reducing uncertainty and strengthening the foundation for the upcoming resource estimate.

Next Steps in Drilling and Modelling

The underground drilling program continues, focusing on further defining the remnant mineralisation’s geometry, delineating mineralisation adjacent to previous mining areas, and improving confidence in the sulphide zone’s continuity. Several drillholes remain pending assay results, and ongoing interpretation will guide targeting of additional high-grade zones within the upper Main Lode. This work aligns with Polymetals’ strategy to leverage near-mine exploration to underpin sustainable production growth at Endeavor.