Broken Hill Mines Ltd. (BHM) has confirmed a major new discovery of bulk-tonnage, high-grade silver, lead and zinc mineralisation at its Rasp Mine in New South Wales, expanding the resource zone across a 1,600-metre strike length.
Assay results from the company’s ongoing drill program into the Centenary Zone, located roughly 250 metres from existing underground operations, have delivered thick, high-grade intercepts situated outside the current Mineral Resource Estimate (MRE).
Highlight assays include drill hole WMDD6400W1, which returned 17.8 metres at 10.1 per cent zinc equivalent (ZnEq) and 280g/t silver equivalent (AgEq) from 420 metres. This included a higher-grade zone of 5.4 metres at 19.5 per cent ZnEq and 540g/t AgEq.
The silver grades returned in WMDD6400W1 are up to 4.4 times higher than those modelled in the historical Centenary MRE, which currently stands at an inferred 4.8 million tonnes at 9.2 per cent ZnEq.
The drilling success stems from an innovative technique where BHM cased large-diameter holes directly through the complex Globe-Vauxhall Shear, allowing accurate daughter holes to target the zone below without trajectory distortion, a structural challenge that historically hampered exploration efforts.
Mineralogical analysis indicates that the Centenary Zone shares a close geological affinity with the iconic Main Lode orebody rather than adjacent lower-grade zones, pointing to significant upside potential in both grade and scale.
A visual inspection of the latest completed hole, WMDD6389A, shows a mineralised zone up to 35 metres thick, with laboratory assays expected in the coming weeks.
The company is expediting a complete reinterpretation of historical data to establish a new Exploration Target, ahead of an upgraded MRE scheduled for the fourth quarter of 2026.
BHM expects the Centenary Zone will provide high-grade, bulk-tonnage feed for its 750,000-tonne-per-annum processing plant, potentially underpinning a medium-term processing expansion.
