Black Bear Minerals (ASX:BKB) has extended historic core re-analysis across all available drill programs after further assays confirmed ‘higher silver grades’ at the Shafter Silver Project in Texas, US.
Re-analysis of two 2012 diamond holes returned silver (Ag) grades up to 2,990 grams per tonne.
Hole S‑12‑403 intersected 9.1m @ 1,043g/t Ag from 116.4m, including 0.6m at 2,990g/t Ag — a 133% increase in grade for the internal interval and 30% increase in contained silver for the broader intercept compared to the original database.
Hole S‑12‑420 returned 15.5m @ 299g/t Ag from 144.5m, including 4.3m @ 994g/t silver. This represents a 5% increase in contained silver compared to historical results.
CEO Dennis Lindgren says that “Shafter continues to surprise on the upside”.
“These latest results include 9.1 metres at 1,043g/t silver with a peak of 2,990g/t, while also identifying up to 0.8g/t gold and base metals, largely absent from historic datasets,” Lindgren adds.
The re-analysis program has now covered nine drill holes and 233 comparable assay pairs across campaigns spanning 1980 to 2012. All holes re‑analysed since Black Bear acquired the project have returned increased silver grades for broader intercepts.
Re-analysis has also confirmed polymetallic mineralisation up to 0.8g/t gold and 30% lead, with historic samples previously analysed for silver only.
The company attributes higher silver grades to modern four‑acid digest methods compared to historic two‑acid digest methods.
The Shafter Project hosts a 17.6 million ounce (Moz) foreign mineral resource estimate prepared under NI 43‑101 standards. Black Bear Minerals is working to convert the estimate to JORC standards while progressing the Rapid Mine Restart Study.
Shafter spans approximately 4km of strike and was historically worked as the Presidio Mine from 1883 until 1942. The historic mine produced 35.2Moz Ag at an average grade of 521g/t Ag.
Write to JC Villarba at Mining.com.au
Images: Black Bear Minerals
