ExplorationTrevali's initial 2008/09 Santander exploration program focused on resource delineation drilling of its three silver-lead-zinc mineralized manto and pipe-type structures. The Magistral North, Central and South deposits are all new discoveries hosted in favourable carbonate lithologies and located just a couple of kilometres Northwest and along the same structural trend hosting the past producing Santander orebody that was mined from 1958 until 1991.
Initial drill results from the Magistral deposits were very encouraging with almost all of the 165 holes completed (totalling approximately 32,000 metres) encountering significant intercepts of polymetallic sulphide mineralization (Ag-Pb-Zn) from surface to depths of more than 350 metres below surface. Mineralization remains open for expansion at depth and to the East in all three deposits.
The data from this drilling led to an initial independent (NI 43-101) resource estimate by Golder Associates completed in mid-2009 reviewing an indicated resource of 390 million contained lbs zinc, 149 million lbs lead and 6.5 million ozs silver in 5,298,000 tonnes at an average grade of 3.34% zinc, 1.27% lead and 38 g/t silver in the Magistral North, Central and South deposits using a 2% ZnEQ* cut-off grade. Additional inferred resources of 144 million contained lbs zinc, 25 million lbs lead and 1.3 million ozs silver in 2,244,000 tonnes at 2.92% zinc, 0.50% lead and 18 g/t silver also reviewed using same cut-off grade.
Follow-up drilling in 2009/10 focused on expanding mineralization on the three Magistral deposits as well as testing of a fourth mineralized zone (Puajanca South) that returned significant silver and base metal values. Puajanca South is situated about one kilometre Northeast of the Magistral North Deposit and is undergoing a resource definition drill program. An updated resource estimate from Golder Associates incorporating results from this drill program is anticipated later in the year.
Additionally several geophysical anomalies, similar to those coincident to the Magistral bodies, are undergoing follow-up exploration on the Company's 44-km2 mineral concession.
*ZnEQ = ((Ag Price(g) x Ag Recovery x Ag Grade) + (Pb Price(t) x Pb Recovery x (Pb Grade(%)/100)+(Zn Price(t) x Zn Recovery x (Zn Grade(%)/100)))/Zn Price(t). Golder Associates utilized the three year rolling average price for all three metals. Price for silver is per gram ($0.43339) and that for Pb ($1,983) and Zn ($2,742) is per tonne. A recovery of 85% was applied to Ag, 94% for Pb and 91% for Zn based upon Trevali's metallurgical test-work. A 2% ZnEQ* cut-off grade is the nominal base case estimated grade of material that can be mined and processed considering all applicable costs.