Significant intersections to date from the Sorpresa system illustrate the potential for high grade, and broad width intersections in the oxide zone,including narrower high grade to bonanza grade gold in the oxide and primary.
A JORC 2012 Compliant Maiden Mineral Resource Estimate for the Sorpresa system was completed in Dec 2014. This represented a significant milestone for Company. The mineralized system at Sorpresa is a complex overlap of gold and silver mineralization, particularly in the northern Roadside area, therefore reporting provides an account of the individual metals, and also the combined metals, within the constraints of the JORC 2012 code.
Not only does the resource contain approximately 6.4Mt for 7.9 million ounces of silver and 125,000 Oz of gold (at a 0.5g/t Au & 25g/t Ag cutoff), but at higher cut off grades there is potential for shallow resources at surface, typified by the fact that 70% of the gold ounces and 62% of the silver ounces are within 100m of surface. This includes 1.2Mt @ 1.22g/t Au (0.5g/t Au cutoff) for 47kOz Au of Oxide material.
Approximately 70% of the gold ounces and 75% of the silver ounces in the resource is in the Indicated Mineral Resource category, with a target to cost effectively convert a significant proportion of the near surface mineralisation to the Measured category in 2015~16.
Full details of the resource estimate can be viewed (here)
Preliminary Oxide metallurgy was completed late 2013 on 3 composite Oxide Zone samples across 3 locations comprising 130m of mineralization in 30 drill holes. With a standard 24 hr CIL test at 75 micron, very good recoveries were returned, and no problems with clays or carbon / graphite were encountered.
Additional testing on Met1 - Silver Roadside* via a 48 hour CIL, finer grind, improved recoveries to 89.1% for gold and 72.3% for silver. Further metallurgy was undertaken in 2015, including floatation and gravity recoveries, and also in the primary zone.