Polymetals Confirms High-Grade Silver-Lead-Zinc at Endeavor Upper Main Lode

Consistent High-Grade Mineralisation Emerges from Upper Main Lode Drilling

Polymetals Resources Ltd (ASX:POL) has delivered a fresh tranche of underground drilling results that reinforce the presence of broad, high-grade silver-lead-zinc mineralisation at the Endeavor Mine in Cobar, New South Wales. Nine new diamond drillholes have all intersected significant mineralisation, with silver equivalent (AgEq) grades reaching as high as 718 g/t over 30 metres in one hole (POL020), confirming the company's reinterpretation of a 1996 subsidence event that previously complicated resource assessments.

The standout intercepts include a 96.6-metre interval grading 604 g/t AgEq (390 g/t silver, 8.8% zinc, 5.4% lead) in POL015, and a 48.4-metre section at 666 g/t AgEq (451 g/t silver, 7.8% zinc, 6.1% lead) in POL016. These results build on earlier June 2026 assays and demonstrate not just isolated pockets but continuous mineralised zones adjacent to existing underground workings.

From Proof-of-Concept to Resource Definition

Executive Exploration Director Jess Oram highlighted that the drilling program has moved beyond proving the concept to defining the geometry and continuity of mineralisation needed for a Mineral Resource estimate. "Each new hole increases our confidence that substantial high-grade mineralisation remains outside the area affected by the 1996 subsidence," Oram said. The company now targets an updated Mineral Resource estimate for the upper Main Lode by the end of 2026.

The drilling approach has been methodical, using underground diamond drilling with triple tube NQ3 core to maximise sample recovery and data quality. The program is designed to delineate the limits of the interpreted collapse zone and improve geological confidence, supporting future mine planning. The consistent results also suggest the upper Main Lode could become a meaningful addition to the Endeavor mining inventory.

Technical Rigor and Historical Context

Polymetals has incorporated extensive historical data from previous operators, including Electrolytic Zinc Company of Australasia and Pasminco, to inform its geological model. The deposit is classified as a "Cobar-type" polymetallic system, characterised by steeply dipping sub-vertical pipes of massive sulphide mineralisation within turbidite sequences and limestone. The company’s metal equivalent calculations exclude gold pending assay results but factor in silver, lead, zinc, and copper based on current metal prices and metallurgical recoveries.

Assays were conducted by ALS Laboratories with rigorous QAQC protocols, including blanks, duplicates, and certified reference materials. The data integrity supports the confidence in the emerging resource model. Polymetals is also preparing to exchange a $27.96 million rehabilitation bond with the NSW Resources Regulator, reflecting its regulatory compliance and operational progress.

Ongoing Drilling and Strategic Implications

The underground diamond drilling program continues, aiming to complete a 34-hole, approximately 3,100-metre campaign. The remaining holes will further define the collapse zone boundaries and assess additional high-grade tonnes for potential inclusion in mine plans. The company’s approach leverages existing infrastructure and near-mine exploration to unlock value in one of Australia’s most prospective polymetallic districts.

While the drilling results are promising, some assay results remain pending, including gold assays which could enhance the silver equivalent grades. The reinterpretation of the 1996 subsidence, though increasingly validated, may require further drilling to fully delineate the affected zones. The upcoming Mineral Resource update will be a critical milestone to watch, as it will clarify the scale and quality of the resource upgrade and its potential impact on production and valuation.