Inferred resource of 1.57 million tonnes containing 245,145 oz of gold at 4.86 g/t
VANCOUVER, BC, April 16, 2012 -- Grande Portage Resources Ltd. (TSX-V GPG) ("Grande Portage" or "the Company") and its joint venture partner Quaterra Resources Inc. (TSX-V: QTA, NYSE Amex: QMM) are pleased to report a first independent resource estimate for the Herbert Glacier gold project located near Juneau, Alaska.
The resource estimate, which is based on drill results from two of four principal veins on the property, contains an inferred resource of 245,145 ounces of gold at an average grade of 4.86 g/t (0.142 ounces per ton) in 1.57 million tonnes. The resource was calculated using a 2 g/t gold cut-off grade. Assay composites used in the resource estimate were statistically capped at 40 g/t (1.167 ounces per ton) to insure that outliers are not over-influencing the estimation and to account for nugget effect. The resource remains open in multiple directions along these defined veins. In addition, several highly prospective structures spread over the property remain unexplored. (For details of the resource estimate see table below).
The inferred resource released today is the result of two years of drilling along the Main and Deep Trench veins and represents about 20% of the total mapped strike length of all the veins identified on the property. The resource estimate is based on results from 65 diamond core holes (9,386 meters of drilling) and 4 trenches (19.7 meters of trenching) targeting two of the vein structures. The deposit contains coarse visible gold in several drill-hole intervals with gold grades as high as 229 g/t (6.678 ounces per ton) in recent drilling (Drill hole 11I-4).
The resource model on the Main Vein extends for 680 meters along strike and 200 meters down dip, enclosing 27 mineralized intersections in both the Main Vein and a sub-parallel hanging wall vein (the Main Vein Splaywith five mineralized intervals). The undrilled surface exposure of the Main Vein continues for another 280 meters along strike and the resource model also remains open down dip. The Deep Trench Vein resource model extends for 410 meters along strike and 300 meters down dip, enclosing 15 mineralized intersections. The Deep Trench Vein remains open along strike (where another 520 meters of mapped surface exposure remains unexplored) and down dip.
"We are delighted with the initial report," says Grande Portage CEO Ian Klassen. "A small portion of the Herbert Glacier vein system has produced a substantial resource which remains open in multiple directions and depth. This summer's drilling program will provide an opportunity to expand the known resource and to discover additional mineralized zones."
Grande Portage will continue to advance the Herbert Glacier Project through 2012 with a work-program comprised of infill and exploration drilling. This program will consist of 12,000 meters of infill drilling designed at a nominal drill hole spacing of 25 meters with the objective of expanding and confirming the "inferred" resource to "indicated"; and 3,000 meters of exploratory drilling both within other vein targets (Goat and Ridge Veins) and along the open strike extents of the Main and Deep Trench Veins.
The Herbert Glacier project is located in the heart of the historic Juneau Gold District, in south east Alaska. Mineralization at the property consists of mesothermal quartz-carbonate-gold-base metal veins similar to those in other historic mines in the district. Four principal veins have been identified, which from south to north include the Floyd, Deep Trench, Main, and Goat veins. Minor veins include the North, Ridge and Lake veins. The principal veins strike N80E and dip steeply to the north. The present cumulative strike length of all mapped veins on the property is over 5,550 meters.
Herbert Glacier Project: Inferred Resource Estimate (April 2012)
Throughout this release g/t refers to grams per metric tonne.
The mineral resource estimation for the Herbert Glacier Property disclosed in this press release was supervised by Mr. William Burnett of Yukuskokon Professional Services, LLC., in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Standards on Mineral Resources and Mineral Reserves, adopted by CIM Council, as amended. Block grades were estimated by inverse distance weighting to the second power (ID2) within domains based on the interpretation of geologic parameters logged in 65 drill holes and four trenches. Plan sections spaced at 25 to 100 meters were used for the constraint interpretations by Mr. William Burnett, P.Geo., and Dr. Nicholas Van Wyck, P.Geo. of Yukuskokon Professional Services, LLC. Quality-control data, generated during the various drill programs conducted at Herbert Glacier, were independently verified by Mr. Burnett and Dr. Van Wyck as part of the project review. Bulk density for the Hebert Glacier mineralised rock is defined as 2.65 tonnes/m3.
Mr. Burnett and Dr. Van Wyck are co-authors of a Technical Report on the Mineral Resource Estimate for the Herbert Glacier deposit, to be filed within 45 days of this news release. Mr. Burnett and Dr. Van Wyck are independent of Grande Portage Resources Ltd. and Quaterra Respources Inc. and are Qualified Persons as defined by NI 43-101, and are responsible for the content of this press release.
Mineral resources that are not mineral reserves do not have demonstrated economic viability. Mineral resource estimates do not account for mineability, selectivity, mining loss and dilution. These mineral resource estimates include inferred mineral resources that are normally considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. There is also no certainty that these inferred mineral resources will be converted to measured and indicated categories through further drilling, or into mineral reserves, once economic considerations are applied. The mineral resource estimates referenced in this press release use the terms "Indicated Mineral Resources" and "Inferred Mineral Resources". While these terms are defined in and required by Canadian regulations (under NI 43-101), these terms are not recognized by the U.S. Securities and Exchange Commission ("SEC"). "Inferred Mineral Resources" have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. The SEC normally only permits issuers to report mineralization that does not constitute SEC Industry Guide 7 compliant "reserves" as in-place tonnage and grade without reference to unit measures. U.S. investors are cautioned not to assume that any part or all of mineral deposits in these categories will ever be converted into reserves. Grande Portage Resources Ltd. is not an SEC registered company.
ON BEHALF OF THE BOARD OF DIRECTORS
Ian Klassen, President
For further information please contact:
Mr. Ian Klassen
Phone: (604) 899-0106
Statements about the Company's future expectations and all other statements in this press release other than historical facts are "forward looking statements". Such forward-looking statements are based on numerous assumptions, and involve known and unknown risks, uncertainties and other factors, including risks inherent in mineral exploration and development, which may cause the actual results, performance, or achievements of the Company to be materially different from any projected future results, performance, or achievements expressed or implied by such forward-looking statements. NEITHER THE TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICE PROVIDER (AS THAT TERM IS DEFINED UNDER THE POLICIES OF THE EXCHANGE) ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS NEWS RELEASE