Orko Silver Corp. (TSX VENTURE:OK): Orko Silver Corp. ("Orko) is pleased to announce that it has filed a technical report prepared in accordance with National Instrument 43-101 ("NI 43-101") in support of the Company's September 20, 2012, news release, which included an updated mineral resource estimate for its La Preciosa Silver Project in Durango, Mexico.
The independent technical report, entitled "La Preciosa Silver Deposit, Updated Mineral Resource Estimate Statement, Durango, Mexico" (the "Technical Report"), dated November 5, 2012, was prepared by MiningPlus Canada Inc. Vancouver BC, ("MiningPlus") and authored by Darren Head and Michael Collins, Qualified Persons as defined by the requirements of NI 43-101. The Technical Report is available on SEDAR at www.sedar.com and on the Company's website at www.orkosilver.com.
The portion of the mineral resources amenable to open pit mining for the La Preciosa Project are 29,600,000 tonnes grading an average of 104 g/t silver-equivalent classified as Indicated Mineral Resources, with an additional 47,700,000 tonnes grading an average of 87 g/t silver-equivalent classified as Inferred Mineral Resources. This resource is based upon a 25 g/t silver cut-off grade and contained within two potentially economically mineable pit shells.
The portion of mineral resources amenable to underground mining are 54,000 tonnes grading an average of 99 g/t silver-equivalent classified as Indicated Mineral Resources, with an additional 1,900,000 tonnes grading an average of 124 g/t silver-equivalent classified as Inferred Mineral Resources. The resource is based upon a 60 g/t silver cut-off grade to reflect the higher mining costs associated with underground mining methods.
The mineral resources are summarized in Table 1. The updated Indicated Mineral Resource contains an estimated 110,000,000 oz AgEq with another 154,000,000 oz AgEq categorized as Inferred.
Further optimization work on the resource calculation since the published resource estimate on September 20 has resulted in minor changes to the resource, with changes in the overall inferred resource, and slight changes in the indicated resource ("MiningPlus") on the La Preciosa Silver Project. This has resulted in an increase of 12% of the Total Inferred AgEq, a reduction of Underground Indicated and Inferred resources, a reduction of Open Pit grades and an increase of Underground grades. (Table 2).
The mineral resources are reported in accordance with NI 43-101 and have been classified in accordance with standards as defined by the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") "CIM Definition Standards - For Mineral Resources and Mineral Reserves".
This mineral resource estimate has been completed by Bruce Godsmark B.Sc. (MAusIMM) under the direction of Christopher Gee Ph.D., (MAusIMM), Principal Resource Geologist with MiningPlus and Darren Head B.Sc. (MAIG), Manager of Geoscience and Risk with MiningPlus, who have reviewed pertinent geological information in sufficient detail to support the data incorporated in the mineral resource estimate. Mr. Head is an Independent Qualified Person as defined under NI 43-101 and is responsible for the mineral resource estimate presented in this release. Drilling data includes a total of 719 drill holes with 45,118 samples from 237,545 m of drilling. Thirty two drill holes totalling 5,706 m were drilled since the 2011 resource cut-off date of October 2010 and are now included in this resource estimate. No new infill drilling has been completed on the property since January 2011. Wireframes are three-dimensional closed solids constructed in Vulcan(TM) and are based on a combination of logged geology and assay information. These wireframes define the veins and limit the estimation. MiningPlus modeled 68 discrete veins independently to define the current deposit block model, as compared to 18 veins modeled in the mineral resource estimate used in the 2011 PEA.
The average drill sample length for all samples is 0.75 m. Samples were composited to 1.5 m lengths. The estimation was undertaken using ordinary kriging. MiningPlus applied appropriate block model validation techniques for a resource estimation at this stage of project development.
Pit optimization was conducted using Whittle(TM) software to evaluate the block model which was constructed in Vulcan(TM). Underground optimization was conducted using MSO software in a Datamine Studio3 block model derived from the Vulcan(TM) block model. A cut-off grade for the pit and stope optimization of 25 g/t and 60 g/t silver for open pit and underground was used respectively.
Resources are classified as Indicated where the average distance to the closest two drill holes is 38 metres and the distance to the closest sample is less than 38 metres. The Inferred Resources category is defined as areas estimated using at least two composite samples and being within 150 metres of the closest sample.
The majority of holes were drilled with HQ size diamond drill core, reducing to NQ with increasing depth depending on ground conditions. Core samples were cut using a core saw with varied sample lengths not exceeding 1.5 metres in mineralized material. Further Quality Assurance and Control procedures and details on assays are disclosed on the Orko Silver Corp. website and in the report titled "Pan American Silver Corp. and Orko Silver Corp.: La Preciosa Silver Property, Durango, Mexico, Preliminary Economic Assessment - Technical Report" dated 30 June 2011.
AMEC is working on the Preliminary Economic Assessment using the new resource estimate. As part of that work AMEC is currently performing a mill sizing study and reviewing mining options.
George Cavey, P.Geo., is the Qualified Person for Orko Silver Corp. and has approved the technical disclosure in this news release.