Medusa Mining’s Philippines affiliate Philsaga Mining Corporation has completed the annual review and update to its mineral resource and ore reserve estimates at the Co-O Gold Project in the Philippines for the 12 month period ending June 30, 2015.
Indicated resource ounces at the northeast Mindanao project increased by 2% to 604,000 ounces at a 3% higher grade of 12.2 grams/tonne gold while inferred resource ounces decreased by 34% to 545,000 ounces at a 6% lower grade of 9.2 grams/tonne gold.
Total mineral resource ounces decreased by 19% at a 1% higher grade. Probable reserves have decreased by 4% to 427,000 ounces at a 1.5% higher grade of 7.33 grams/tonne gold using a gold price of US$1150 per ounce, which was US$100 lower compared to the gold price used in 2014.
Total inferred and indicated resources for Co-O are now estimated at 3.50 million tonnes at a grade of 10.2 grams/tonne for a total of 1.15 million ounces gold, compared to the estimate reported on September 25, 2014 of 4.34 million tonnes at a grade of 10.1 grams/tonne for a total of 1.41 million ounces.
The changes in resources are primarily due to:
- Mining depletion of 105,000 ounces (98,359 ounces recovered), plus untreated, mined low grade material;
- Inclusion of further underground drilling results and development, resulting in an upgrade in the classification of inferred resources to indicated resources;
- Reduction of some interpreted vein thicknesses at depth, in the inferred category based on vein development in the upper levels;
- The addition of a higher proportion of internal waste to reflect the discontinuous nature of some veins;
- Application of a revised lower cut-off grade to use an accumulation of 3.2 gram metres/tonne to incorporate a minimum mining width above cut-off grade;
- Improved survey practice, resulting in better stope definition; and
- Revision of availability of in-situ pillars due to mining access.
Despite the mining depletion of 105,000 ounces in FY2015, the amount of ounces in the indicated resource category remains largely unchanged, at a slightly higher grade. This is a result primarily of conversion from inferred to indicated by infill drilling and development, rather than extensional resource drilling.