Magellan Minerals Ltd.

Magellan Minerals Ltd.

October 08, 2009 11:48 ET

Magellan Reports Initial Resource Estimate at Coringa Project, Brazil

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Oct. 8, 2009) - Magellan Minerals Ltd. (TSX VENTURE:MNM) ("Magellan") is pleased to report the results of an initial National Instrument (NI) 43-101 compliant resource estimate on its Coringa project, Brazil which has been completed by independent consultants, Global Resource Engineering (GRE) Ltd. The work was originally commissioned by Chapleau Resources Ltd. prior to completion of the business combination with Magellan.


  • The resource estimate completed by GRE includes 269,500 measured and indicated troy ounces of gold representing 982,291 tonnes at an average grade of 8.53 g/t gold and 98,224 inferred troy ounces of gold representing 327,054 tonnes at an average grade of 9.34 g/t ton gold on a diluted basis and using a 2 g/t gold cut-off. 
  • Of the total gold resource reported here, 73% of the total are measured and indicated resources and 27% of the total are inferred resources. Table 1 below presents the Coringa mineral resource by block at a 2 g/t gold cut-off grade.
  • Raising the cut-off grade to 5 g/t gold results in a measured and indicated resource of 0.563 Mt @ 12.37 g/t gold (223,914 troy ounces gold) and an inferred resource of 0.178 Mt @ 14.65 g/t gold (83,873 troy ounces gold) on a diluted basis. Table 2 below presents the Coringa mineral resource by block at a 5 g/t gold cut-off grade.
  • Preliminary metallurgical test work showed that a combination of gravity separation and flotation should result in an estimated 85 to 90% gold recovery. 
  • GRE concluded that "the vein system is open both at depth and along strike" and that "it is highly probably that the main vein system comprised of the 4 resource areas (see plans on Magellan Minerals website) is continuous between blocks".

Geology and Mineralization

The Coringa Project is a shear-vein system, hosted in mid-Proterozoic volcanic rocks and granites on the southern margin of the Tapajos Gold Province. An estimated 10 tonnes of gold has reportedly been produced from alluvial and primary sources at the property.

The main shear structure at the project is approximately 7 km in length, trends 345 degrees and is open both to the north and south. Sub-parallel and parallel shear structures add at least another 2.7 km to the total strike length. The mineralized shear and vein structures vary in width from 15 cm to 4.0 m. Pyrite is the most common sulphide, followed by sphalerite, galena, chalcopyrite, and in a smaller amount covellite. The alteration is mainly sericitization, with some silicification and chloritization which generally occurs as narrow haloes.

Table 1

Coringa Mineral Resource, 2 g/t Gold Cut-Off Grade (Diluted)
October 8, 2009

Resource AreaTonnesAu (troy oz)Au (g/t)
Eloy Juara17,7083,8846.82
Eloy Juara17,3932,6364.71
All Areas982,291269,4508.53
Eloy Juara810682.61
All Areas327,05498,2249.34

Table 2

Coringa Mineral Resource, 5 g/t Gold Cut-Off Grade (Diluted)
October 8, 2009

Resource AreaTonnesAu (troy oz)Au (g/t)
Eloy Juara9,5513,0599.96
Eloy Juara7,1421,5366.69
All Areas563,046223,91412.37
Eloy Juara00 
All Areas178,12383,87314.65

NOTE: Mineral resources that are not reserves do not have demonstrated economic viability. An Inferred Mineral Resource is that part of a mineral resource for which quantity and grade can be estimated on the basis of geological evidence and limited sampling and reasonably assumed, but not verified, geological and grade continuity. An Indicated Mineral Resource is that part of a mineral resource for which quantity, grade or quality, densities, shape and physical characteristics, can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters, to support mine planning and evaluation of the economic viability of the deposit.

The resource estimate used a density of 2.7 t/m3 and dilution representing a minimum mining width of 1.5 m.

Magellan's President and CEO, Alan Carter stated, "We are very pleased with the results of this initial resource estimate at Coringa which covers only 20% of the mineralized structures identified thus far. Both the grade, and the ongoing identification of additional high grade zones and previously undiscovered structures, suggest that Coringa will grow into a major gold deposit."

Further drilling aimed at adding to the known gold resource and testing new targets at Coringa is planned and will be initiated once all outstanding soil sampling results and additional rock sampling of new identified structures have been received and evaluated. Magellan is committed to the completion of a scoping study at Coringa during early 2010.

Coringa Mineral Resource Estimation Methodology

The Coringa mineral resource estimate was prepared under the supervision of Mr. Kevin J. Gunesch a registered Professional Engineer in the state of Alabama (27448) and Principal Mining Engineer of Global Resource Engineering Ltd. (GRE). Christopher K. Chapman a registered Professional Engineer in the State of Colorado (40679) and Principal Mining and Civil Engineer of GRE and Terry A. Lane associate of GRE, AusIMM registered, and Principal Mining Engineer for Gustavson and Associates participated in the Coringa NI 43-101 report preparation. The mineral resource estimate was prepared under Canadian Institute of Mining Metallurgy and Petroleum (CIM) Definition Standards (2005) and CIM Best Practice Guidelines for preparing mineral resources and mineral reserves. Mr. Gunesch is an "independent" and "qualified person" as such terms are defined in NI 43-101.

GRE developed a block model using the drill-hole data from 8,785 m of core drilling in 81 exploration holes, assay results, and geological structure of the deposit. Gold grades were estimated using the inverse distance squared method and were confined to the mineralized zones, which are comprised of gold veins within the "shear" areas of the project. The Mineral Resource estimate for the project was completed independently by GRE using Chapleau's exploration database. Prior to completing the calculation, GRE verified the data contained within the database. This included taking firsthand measurements of the drill holes and comparing them to the database; comparing original handwritten geologic logs to the database and onsite core; completing a review of the quality assurance data gathered from the blanks, standards, and duplicated used in the Quality Assurance/Quality Control (QA/QC) sample program; reviewing the chain of custody sample documentation for completeness; and sending two additional core samples chosen by GRE to verify laboratory assay results. A site visit was performed by Mr. Kevin J. Gunesch P.E. of GRE in May 2009. It is GRE's opinion that the data used for the resource calculation describes the deposit sufficiently to support this technical assessment of the resource. GRE utilized all drill holes to develop continuity of different veins. The veins are sub-parallel, in echelon. Five vein horizons have been modeled. A mine grid was created to simplify the modeling of the steeply dipping deposit. A gridded model covering the Coringa area was built in the mine grid coordinate system, in meters, using Techbase software. The gridded model was defined sufficiently large to cover all drilling and known deposits. The grid size was 10 by 10 meters, orientated vertically. The x coordinate of the hangingwall and footwall contacts was modeled, and the horizontal vein thickness determined by subtracting the footwall coordinate from the hangingwall coordinate. Topography was based on ground survey data provided by Chapleau (comprised of a digital elevation model produced during airborne geophysical surveys combined with the drill-hole collar surveys) and was used to constrain the upper limit of the block model. It should be noted that detailed survey of the artisanal surface workings has not been performed and is recommended for future work.

Grade was estimated separately for the vein, hangingwall, and footwall using the composite data for each of these regions. Grade was estimated using the inverse distance squared relationship and a search distance of 100 m. The tonnage of each block was estimated using a global average density of 2.7 t/m3.

Resources were calculated for gold cutoff grades of 2 g/t, 3 g/t, 4 g/t, and 5 g/t, for both undiluted and diluted conditions. Blocks located within 1/3rd of the variogram range (33 meters) of composites exceeding the cutoff grade were classified as measured resources, those falling between 1/3rd and 2/3rds of the variogram range (33 meters and 67 meters) were classified as indicated resources, and those falling between 67 meters and 100 meters were classified as inferred resources. Dilution calculations considered a minimum mining width of 1.5 meters and a minimum 0.3 meters dilution on both the hangingwall and footwall This means that for vein thicknesses equal to or greater than 0.9 meters, dilution is taken equally from the hangingwall and footwall at 0.3 meters thickness. For vein thicknesses less than 0.9 meters, greater than 0.3 meters of dilution must be taken from either the hangingwall or footwall in order to achieve a minimum mining width of 1.5 meters. In this case, the grades of the hangingwall and footwall were compared and greater dilution taken from the side with the higher grade.

The complete NI 43-101 report on the Coringa project will be filed on SEDAR within the next 45 days.

Ian Gendall (Pr. Sci. Nat.), Magellan's Chief Operating Officer and a "qualified person" within the definition of that term in NI 43-101, has reviewed the technical information contained in this news release.

This news release may contain forward-looking statements including but not limited to comments regarding the timing and content of upcoming work programs, geological interpretations, receipt of property titles, potential mineral recovery processes, etc. Forward-looking statements address future events and conditions and therefore, involve inherent risks and uncertainties. Actual results may differ materially from those currently anticipated in such statements.

The TSX Venture Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.

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