Updated Mineral Resources At Topia Mine
VANCOUVER, Great Panther Silver reported an update to the Mineral Resource Estimate (MRE) at the Company's 100% owned Topia Silver-Gold-Lead-Zinc Mine in Durango, Mexico.
Highlights of the updated Mineral Resource Estimate: Measured & Indicated (M&I) mineral resources increased by 41%, year over year, to 346,200 tonnes grading 624g/t silver, 1.31g/t gold, 4.50% lead and 4.19% zinc, containing 11.58 million silver equivalent ounces (Ag eq oz); Inferred mineral resources increased by 29%, year over year, to 357,400 tonnes grading 592g/t silver, 1.31g/t gold, 3.44% lead and 3.96% zinc, containing 11.05 million Ag eq oz.
"The significant increase in the Topia Mineral Resource Estimate reflects continual refinements and improvements in our resource model," stated Robert Archer, President & CEO. "The improved modeling, successful in-vein development and better reconciliation between the geological model and actual mine output resulted in an increase in estimated tonnage and contained ounces, in spite of a notable drop in the silver price. In addition, our operations team continues to convert Inferred resources to M&I resources through underground development and sampling, underpinning the long mine life at Topia."
This MRE provides an update for 40 veins from nine mining areas. It is based on an approximate average Net Smelter Return (NSR) cut-off value of US$180/tonne, corresponding to 2014 mining, processing, concentrate shipment and treatment, and general and administrative costs for each mining area. Capping of grades and a minimum true width of 0.30 meters were individually applied to each of the veins.
While most of the current resource base came from Great Panther's diamond drilling and underground development, the resource estimated for certain veins on the property (e.g. Argentina) came largely from the verification of Peûoles' sampling on levels that are planned for access in 2015 and later, and are still intact. The majority of Great Panther's mining to date has come from new mine development on veins reported in these estimates.
Due to the steep topography and the nature of the narrow veins at Topia, surface drilling is typically widely spaced and is used as a guide for underground development by locating and confirming structural continuity and grade, while development by drifting, sampling, and some underground drilling along the veins defines the M&I mineral resource. Accordingly, surface drilling is used to determine Inferred resources.
The 40 veins or vein segments from which this MRE was derived, were wire-framed using Leapfrog software. A minimum 0.30 meter width was set to the wire-frames. Geological interpretation of the veins was based on detailed level mapping along the veins, surface and underground drilling, and the insights of the site mine geologist. The block modeling was conducted using Micro Mine software and the Inverse Distance Cubed grade estimation method. The grade of samples less than 0.30 meters in length/width was diluted to the minimum true width of 0.30 meters. The NSR calculation was then completed on diluted and capped block model assays.