43-101 NEWSResource Estimate For Strieborna Vein Silver Project Completed, Moving Forward To Preliminary Feasibility Study Recommended
VANCOUVER, Apr 23, 2008 (Canada NewsWire via COMTEX News Network) --
Global Minerals Ltd. (CTG: TSX-Venture Exchange, DFP: Frankfurt Exchange, OTC: GMLFF.PK) is pleased to announce that the Technical Report on the Strieborna Vein silver-copper-antimony project (Strieborna Project) in eastern Slovakia, dated April 22, 2008, has been received.
This report has been prepared by Eur Ing Zygmunt Jakubiak, Principal Geologist of AMC Consultants Pty Ltd (AMC), Melbourne, Australia, on behalf of Global Minerals Ltd. (the Issuer) of Vancouver, Canada. The main purpose of the report is to present AMC's estimate of the current mineral resource in accordance with the requirements of National Instrument 43-101 (NI 43-101), "Standards of Disclosure for Mineral Projects", of the Canadian Securities Administrators. The author meets the requirements of a Qualified Person as defined in NI 43-101 and is independent of the Issuer.
Current Resource Estimate
A summary of the mineral resource is given in Table 1. The mineral resource is reported without a cut off grade applied as the form of the deposit and the mean silver, copper, antimony and iron grades are such that the Strieborna Vein has reasonable prospects for economic extraction in its entirety. The terms Mineral Resource, Measured Mineral Resource, Indicated Mineral Resource and Inferred Mineral Resource have the meanings ascribed to those terms by the Canadian Institute of Mining, Metallurgy and Petroleum as the CIM Standards on Mineral Resources and Reserves Definitions and Guidelines adopted by CIM Council on August 20, 2000. The measured and indicated mineral resource categories for the Strieborna deposit are defined with sufficient confidence to support a Preliminary Feasibility Study.
<< Table 1. Current Mineral Resource of the Strieborna Vein ------------------------------------------------------------------------- Mineral Average Grades Resource Quantity Horizontal ------------------------------------------ Category Width Ag Cu Sb Fe ---------------------------------------------------------------- mt m g/t % % % ------------------------------------------------------------------------- Measured 215,000 5.8 468 2.2 1.4 20.6 ------------------------------------------------------------------------- Indicat- ed 1,710,000 3.4 202 1.0 0.6 33.2 ------------------------------------------------------------------------- Inferred 1,500,000 3.2 180 0.9 0.6 33.6 ------------------------------------------------------------------------- NB: Tonnage includes estimated 35,000 tonnes of mined out developmentmaterial. A summary of the estimated contained metals for each resource category inthe Strieborna deposit, expressed in troy ounces (oz) of silver (Ag),pounds (lb) of copper (Cu), pounds (lb) of antimony (Sb), and metric tonnes(mt) of iron (Fe), is given in Table 2. Table 2. Contained Metals in the Strieborna Vein ------------------------------------------------------------------------- Mineral Estimated Metal Content Resource Quantity ---------------------------------------------- Category Ag Cu Sb Fe ---------------------------------------------------------- mt oz lb lb mt ------------------------------------------------------------------------- Measured 215,000 3,235,000 10,430,000 6,640,000 44,300 ------------------------------------------------------------------------- Indicated 1,710,000 11,105,000 37,705,000 22,625,000 568,000 ------------------------------------------------------------------------- Inferred 1,500,000 8,680,000 29,770,000 19,845,000 504,000 ------------------------------------------------------------------------- NB: Please refer to Table 1 (above) for the average metal grades of eachresource category. A summary of the combined measured and indicated mineral resourcecategories for the Strieborna deposit applying various Ag cut-off grades, isgiven in Table 3. Table 3. Measured + Indicated Resources of the Strieborna Vein at various Ag cut-off grades ------------------------------------------------------------------------- Cut-off grade Quantity Ag Cu Sb Fe g/t Ag mt g/t % % % ------------------------------------------------------------------------- 100 1,440,000 290 1.4 0.90 31.4 ------------------------------------------------------------------------- 125 1,280,000 313 1.5 0.95 31.2 ------------------------------------------------------------------------- 150 1,080,000 345 1.6 1.05 30.8 ------------------------------------------------------------------------- 175 965,000 367 1.7 1.10 30.5 ------------------------------------------------------------------------- 200 855,000 390 1.8 1.15 30.2 ------------------------------------------------------------------------- 225 765,000 410 1.9 1.20 30.2 ------------------------------------------------------------------------- 250 670,000 435 2.0 1.30 29.9 ------------------------------------------------------------------------- 275 585,000 460 2.1 1.35 29.5 ------------------------------------------------------------------------- 300 520,000 480 2.2 1.40 29.2 ------------------------------------------------------------------------- >>
NB: Resources do not have demonstrated economic viability, and any in-situ values that may be calculated from metal contained in mineral resources may not represent the exploitable value of the deposit.
The Strieborna Vein deposit
Following its discovery in 1981, the Strieborna Vein was systematically explored on four underground levels totalling over 3,000 m in length. The Exploration Branch of the Slovak Geological Survey conducted exploration in three phases from 1982 to 1994. The exploratory underground workings comprise drives either directly in the vein or in its footwall with sampling crosscuts at regular intervals to intersect the whole width of the vein. In addition, the vein has been exposed along strike on two sublevels, totalling 170m in length, and in two raises.
The Strieborna Vein strikes north-east and has a propeller shape with subvertical dips in the centre changing to south-eastern dips in the south-western part of the vein and to north-western dips in the north-east. Vein widths range from less than a meter to 8 m, averaging about 2.5 m. Its vertical extent is over 500 m. The vein has no surface exposure, although there are traces of old workings that could follow a subsidiary vein structure branching off the Strieborna Vein.
Tetrahedrite mineralisation was emplaced into a complicated system of fractures developed along the margins of quartz ladder veins and within siderite during late stages of brittle deformation. The mineralisation is unevenly distributed and its intensity is a function of the intensity of deformation, which was controlled by the ductility of the host rocks. Accordingly, the highest silver-copper-antimony grades are in those parts of the vein which are hosted by relatively ductile quartz-sericite phyllites on Levels 8 and 9 whilst lower grade mineralisation developed in parts of the vein hosted by competent porphyroids (mostly on Level 13).
Basis of Resource Estimate
Results reported by the Slovak Geological Survey were checked in a program undertaken by London-based CMX Resources Limited (CMX). The program involved detailed geological mapping of the underground workings, structural and mineralogical studies and verification sampling. The CMX work confirmed geological interpretations made by the Slovak Geological Survey and the overall grade distribution on the various levels of the underground development. The CMX program was conducted in 1994 and was the last exploration activity on site. The underground workings were flooded in 1998-2000.
AMC has estimated the current mineral resource using a database generated by the Slovak Geological Survey and incorporated CMX sampling results from Sublevel 9, which is situated 8 m above Level 9. The database used in the estimate comprises 394 underground channel samples and ten drillhole intercepts. The estimation was done in a vertical plane parallel to the overall strike of the vein with the block model projected onto it. Ordinary kriging was used for grade estimation. Once grades were estimated, the block model was returned to its original position.
Metallurgical Testwork
Process testwork on a bulk sample from the Strieborna Vein using the process developed by Sunshine Mining and Refining Company indicated that 90-95% of the tetrahedrite bearing silver and copper can be recovered by flotation. The flotation concentrate can then be treated for selective removal of antimony, arsenic and mercury using alkaline sulphide hydrometallurgy. From this, antimony or value-added antimony products can be produced, whilst arsenic and mercury can be precipitated, stabilized and disposed of in a managed waste disposal facility.
Recommendations
The author of this report recommends that the Issuer take all necessary steps to complete a Preliminary Feasibility Study, and further recommends that, subject to a positive outcome of that Preliminary Feasibility Study, the Issuer proceed with a Full Feasibility Study to evaluate the economic feasibility of the selected development and production option to a the level of accuracy required for project financing.
About AMC
AMC is a leading international mining consultancy. Mineral resource and reserve evaluation are core elements of AMC's capabilities, and its evaluation reports comply with the CIM Standards on Mineral Resources and Reserves Definitions and Guidelines, and with other internationally accepted reporting standards. Eur Ing Zygmunt Jakubiak, who prepared this Current Mineral Resource Estimate, has sufficient experience relevant to both the vein-type precious metals deposits and to the work that he has undertaken to be a Qualified Person as defined under the applicable guidelines of NI 43-101.
About Global Minerals Ltd.
Global Minerals is a Canadian-based company with focus on the acquisition, exploration and development of mineral property interests.
George W. Heard, BSc, MBA, PEng, President and CEO of Global Minerals Ltd., a qualified person in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects, prepared this news release.
Global Minerals Ltd.
"George W. Heard"
George W. Heard
President and CEO
The TSX Venture Exchange has not reviewed and does not accept
responsibility for the adequacy of this news release.
SOURCE: Global Minerals Ltd.
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