2011 News Releases
Excelsior Reports Indicated Resource of 3.2 Billion Pounds Oxide Copper at North Star
July 19, 2011
Excelsior Mining Corp. (TSX-V: MIN) (Frankfurt: 3XS) (OTCQX: EXMGF) (“Excelsior”) is pleased to announce a significant increase to the mineral resource estimate at the North Star Deposit. The oxide copper (Cu) mineral resource has increased from 2.86 billion pounds of Cu (404 million tons at 0.35% Cu) in the inferred category to an indicated copper resource of 3.21 billion pounds and an additional inferred resource of 0.88 billion pounds Cu (refer to table below for tonnage and grade details). The North Star Deposit is part of the Gunnison Copper Property located within the copper porphyry belt in southern Arizona.
The South Star Deposit was not drilled this year and remains unchanged with an inferred resource of 0.38 billion pounds of oxide Cu (62 million tons at 0.30% Cu at a cut-off of 0.1% Cu – see news release dated November 2, 2010).
“We are extremely excited about our updated resource as we not only moved the majority of the oxide resource from the inferred to the indicated category, but we also significantly increased the global resource,” says Stephen Twyerould, President and CEO of Excelsior. “As our plan is to mine Gunnison using in-situ recovery mining techniques, our focus is the oxide component of the property, although the mixed and sulphide components have also significantly increased. This upgraded resource represents the first of several milestones that Excelsior aims to achieve over the coming months.”
NORTH STAR RESOURCE (OXIDE ONLY AT 0.1% CUT-OFF)
NORTH STAR RESOURCE (OXIDE ONLY AT 0.3% CUT-OFF)
NORTH STAR RESOURCE (OXIDE, MIXED & SULPHIDE)
Note: 0.1% cut-off for Oxide component and 0.3% cut-off for Mixed and Sulphide components
Resource Estimate Details
The mineral resource estimate for the North Star Deposit is based on results from 109 drill holes totalling 141,252 feet (ft) and is effective as of June 20th, 2011. Mr. Herb Welhener, (MMSA-QP) with the independent firm, Independent Mining Consultant of Tucson, Arizona is a Qualified Person as defined by NI 43-101 and is responsible for this mineral resource estimate. He has verified, reviewed and approved the technical disclosure contained in this news release and underlying sampling, analytical and test data. The estimate is classified as an indicated or inferred mineral resource, consistent with the CIM definitions referred to in NI 43-101. This NI 43-101 compliant estimate will be filed in a Technical Report on SEDAR within 45 days of this news release. Excelsior is not aware of any environmental, permitting, legal, title, taxation, socio-political, marketing or other issues which may materially affect its estimate of mineral resources.
The mineral resource estimate is contained within a block model of the North Star deposit covering a surface area of 3.30 square miles and to a maximum depth of 2,575 feet below the topographic surface. The major geologic formations and oxidization types are incorporated into the block model based on the drill hole intercept data. The copper grades are estimated using an ordinary kriging estimation technique from 25 ft drill hole composite data. The grade estimate uses a 700 ft circular by 50 ft search distance dipping 30 degrees east to parallel the general dip of the sedimentary units. The 700 ft distance is 70% of the variogram range and the indicated category requires three or more holes within the search distance. All other blocks which received a grade estimate are classified as inferred. No copper grades are estimated in to the overburden or the non-sedimentary rock units.
All samples are prepared from manually split half-core sections on site in Arizona. Split drill core samples are then sent to Skyline Assayers & Laboratories in Tucson, Arizona for Total Copper and Sequential Copper analyses. Standards, blanks, and duplicate assays are included at regular intervals in each sample batch submitted from the field as part of an ongoing Quality Assurance/Quality Control Program.
Excelsior is an exploration and development company with a copper project located within the copper porphyry belt of Arizona. The Gunnison Copper Project is located close to the required infrastructure and with its in-situ recovery potential, is intended for near-term production. The Excelsior team consists of experienced professionals with proven track records of advancing projects towards production.
Further details about Excelsior can be found at: www.excelsiormining.com.
ON BEHALF OF THE EXCELSIOR BOARD
Cautionary Note Regarding Forward-Looking Information
Cautionary Note Concerning Reserve and Resource Estimates
National Instrument 43-101 Standards of Disclosure for Mineral Projects (“NI 43-101”) is a rule developed by the Canadian Securities Administrators, which established standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects. Unless otherwise indicated, all reserve and resource estimates referred to in this press release or released by the Company in the future have been or will be prepared in accordance with NI 43-101 and the Canadian Institute of Mining, Metallurgy and Petroleum Classification System. The requirements of NI 43-101 are not the same as those of the SEC and any reserves reported by the Company in compliance with NI 43-101 may not qualify as reserves under the SEC’s standards.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release, and no securities regulatory authority has either approved or disapproved of the contents of this release.