Broken Hill Mines (ASX:BHM) has returned thick silver, lead, and zinc intersections outside the Centenary Zone mineral resource estimate (MRE) at its Rasp Mine in New South Wales.
Hole WMDD6400W1 intersected 17.8m @ 10.1% zinc equivalent (ZnEq) and 280 grams per tonne silver equivalent (AgEq) from 420m. This included 5.4m @ 19.5% ZnEq and 540g/t AgEq from 432.4m, containing 173g/t Ag, 7.9% lead, and 6.5% Zn.
Broken Hill Mines says the peak silver grade is about 4.4 times the 39g/t Ag grade within the historical Centenary MRE.
A second hole, WMDD6391W1, returned 14.1m @ 9.4% ZnEq and 261g/t AgEq from 394.8m, alongside 11.1m @ 9% ZnEq and 248g/t AgEq from 420m.
Results follow an earlier intersection of 25.8m @ 11.7% ZnEq and 323g/t AgEq from 415.1m in WMDD6391. The company interprets the three holes as connecting the northern and southern portions of Centenary across its 1,600m strike.
Centenary has an inferred MRE of 4.8 million tonnes @ 9.2% ZnEq and 255g/t AgEq. Although discovered in 1983, only 24 holes had been drilled into the zone before the current program, with most completed from surface during the 1980s.
Previous drilling struggled to penetrate the overlying Globe-Vauxhall Shear without substantial deviation. Broken Hill Mines has instead drilled and cased larger-diameter holes through the structure, allowing narrower daughter holes to reach Centenary.
Visual logging of another hole, WMDD6389A, indicates a zone of potential mineralisation up to 35m thick between the latest assay-backed intersections. Laboratory results are expected within four to six weeks, with visual observations unable to determine metal grades.
The presence of hedenbergite and tetrahedrite has led the company to interpret Centenary as geologically closer to Rasp’s Main Lode than the adjacent Western Mineralisation ore body. Further analysis is planned to test that interpretation.
Drilling is continuing to establish a Centenary exploration target ahead of an MRE update targeted for the December quarter. Located 200–300m from existing declines, ventilation, and haulage infrastructure, Centenary could provide additional feed for Rasp’s 750,000-tonne-per-annum operation, although further drilling and studies are required.
Write to France Pinzon at Mining.com.au
Images: Broken Hill Mines
