The Upper Silesian region is host to a world-class district of Mississippi Valley-Type zinc-lead deposits. Stratiform mineralization occurs largely within a sub-horizontal to gently dipping dolomite unit of Middle Triassic age within a unit referred to as the Ore Bearing Dolomite (OBD), which hosts most of the historical zinc-lead mines in the district as well as currently operating Pomorzany mine. In the area of the Rokitno and Zawiercie concessions drilled by Rathdowney at Project Olza, mineralization within the OBD typically occurs at depths of 100 to 200 metres.
Mineral Resources and Exploration Potential
The current inferred mineral resource (at a 2% Zn cut-off) is 24.4 million tonnes grading 7.02% Zn+Pb is based on both Rathdowney and historical drilling, including additional historical data received to July 2014.
The results presented at a range of cut-offs are shown in the table below.
Contained metal based on 100% recovery. David Gaunt, PGeo., Vice President Resource and Database for Hunter Dickinson Services Inc. (HDSI), a qualified person (QP) who is not independent of the Company is responsible for the estimate. The effective date of the estimate is July 2014. Estimate at 2% Zn cut-off audited and verified by independent QP - L. Roberts, MAusIMM(CP) of SRK for the Preliminary Economic Assessment.
Sample preparation and analytical details for Rathdowney drill holes was done at Omac Laboratories Ltd. (Stewart Group/ALS Laboratory Group), an ISO 17025:2005 accredited facility in Loughrea, Ireland. All samples are assayed for zinc, lead and silver by HNO3, KCLO4 and HBr and the final solution in dilute Aqua Regia is determined by Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES) finish. These three elements and 42 additional elements are also determined for all samples by 4 acid digestion followed by ICP-OES finish. As part of a comprehensive QA/QC program, one standard and one replicate are inserted into the sample stream in each group of 20 samples, as well as one or more blanks in each analytical batch
Historical drilling at Olza had also identified zinc-lead mineralization in a number of other areas on the property. Although drilling in these areas was commonly done on irregular or widely-spaced grids, this historical information, coupled with the results of Rathdowney's drilling, highlights the excellent potential to add mineral resources through further work.
Silver was not analyzed during historical drilling, and so was not estimated in the initial mineral resource. However, results from Rathdowney's drilling indicate the presence of important concentrations of silver within the mineralization, which has the potential to add value to Project Olza.