Lahontan Gold (TSX-V:LG) has reported initial results from sonic drilling at its Santa Fe Mine Project in Nevada, US.
Drilling has intersected 9.9m grading 2.40g/t gold and 50.7g/t silver from a historic ‘low-grade’ stockpile adjacent to heap-leach pad two.
The sonic campaign is evaluating historic heap-leach pads and stockpiles to define gold and silver resources suitable for future reprocessing at lower cost than mining fresh rock.
Stockpiled material was mined from the Santa Fe open pit by previous operator Corona Gold and set aside for potential future processing.
“The low-grade stockpile adjacent to heap-leach pad two has long intrigued our team because it consists of readily accessible mined material that could be potentially crushed and heap leached at relatively low cost,” CEO Kimberly Ann says.
Results confirm significant gold and silver mineralisation within the stockpile, with grades substantially higher than anticipated based on historic classification.
Cyanide-extractable gold assays range from 5–87% of corresponding fire assay values, averaging more than 30%.
Approximately 16 million tonnes of material were processed on the heap-leach pads during historic operations. Ann says residual gold and silver contained within these pads represent a potentially valuable source of low-cost future feed.
Results from six additional sonic drill holes completed on the stockpile are expected shortly. The sonic program has concluded with nearly 100 drill holes completed across the four historic heap-leach pads.
Santa Fe produced 359,202oz gold and 702,067oz silver through open-pit mining with heap-leach processing between 1988 and 1995.
The mine has a National Instrument 43-101-compliant indicated mineral resource of 1,539,000oz gold equivalent and an inferred mineral resource of 411,000oz gold equivalent.
Write to JC Villarba at Mining.com.au
Images: Lahontan Gold
