Infinito announces new Crucitas resource estimate
SYMBOL TSX-V: IG CALGARY, May 29 /PRNewswire-FirstCall/ -- Infinito Gold Ltd. (the "Company") - The Company announces that it has received an updated resource model based on a revised interpretation of its Crucitas Project in Costa Rica produced by Hellman & Schofield ("H&S") of Sydney, Australia in the course of preparing an updated resource estimate for the Project. The updated model significantly increases the estimated resources. Portions of this work were completed by R.J. Morris, M.Sc., P.Geo., a geological consultant based in British Columbia.
The table below summarizes the new resource estimates produced by H&S as of May 19, 2008, which does not include silver values. ------------------------------------------------------------------------- H&S Resource Estimate
The Geostat Estimate, produced in February of 2006, at a 0.5 g/tonne cut off grade estimated an indicated resource of 25.09 million tonnes containing 985,000 oz of gold at an average grade of 1.21 grams of gold per tonne for the deposit. The inferred resource estimated by Geostat at a 0.5 g/tonne cut off grade was 12.57 million tonnes containing 496,000 oz of gold at an average grade of 1.23 grams of gold per tonne. A discussion of the significant differences in the interpretations of the mineralization at the Crucitas Project and its impact on the resource estimates appears below. The Company is now in the process of updating its Feasibility Study that was prepared using the Geostat Estimate and filed on SEDAR on February 26, 2007. Micon International Ltd. ("Micon") who prepared the initial study, has been retained to update their study to incorporate the new resource model prepared by H&S together with updating capital, operating costs and projected revenues to reflect the changes in costs and the price of gold since the original study was prepared. The new resource model does not vary significantly in total volume to be mined from the previous model. The H&S model includes material which was formerly shown as below cut off grade and designated as waste in the Geostat model. This material is not in deeper or potentially higher strip ratio areas and therefore has the potential to be processed under a new mine plan without materially changing the area to be disturbed by mining. If Micon's updated report concludes that this material should be processed and does not thereby materially increase the area to be disturbed by mining, it will likely have the effect of extending the mine life and reducing the strip ratio without materially impacting the size of the mine footprint or the tailings dam contemplated in the original Micon study. Comparison of Interpretations and Estimates H&S assessed gold resources utilizing a block modeling approach based on multiple indicator kriging ("MIK"). The background to this method is discussed in Deutsch and Journel, 1988, "GSLIB: Geostatistical Software Library and User's Guide". H&S has developed its own implementation of MIK which has been in use in gold resource estimation world wide for more than 10 years. Both Placer Dome and Geostat used the method of ordinary kriging in their resource estimation. The other major difference between the Geostat interpretation of 2006 and that of H&S was that the Geostat interpretation subdivides the main bodies of mineralization based on an interpretation of generally north trending, steeply dipping narrow structures which were assumed to control the location of higher grade mineralization. H&S could not find reasonable support for this interpretation either in the drill core or in the spatial analysis of gold data. The resource estimates produced by H&S are more closely aligned with historical estimates produced by Placer Dome Inc. (Placer) and Independent Mining Consultants (IMC). These are set forth below and the information is taken from the Geostat Technical Report filed on Sedar on April 10, 2006. ------------------------------------------------------------------------- Gold Millions # of Summary of Selected Historical Resource Estimates H&S advises that it has used a standard implementation of multiple indicator kriging with block support correction for the estimation of recoverable resources over the past ten years in many gold deposits exhibiting varying and complex styles of mineralization. H&S considers the MIK approach to be both robust with respect to the problems presented by extreme grades in samples and provides estimates of resources that are reasonably consistent with production over periods of time as short as one to three months where appropriate ore control methods are used. H&S comments that the total resource estimates at a 0.3 g/t cut off in their model are similar to those estimated by Placer Dome in 1996 at a 0.5 g/t cut off. At a 0.7g/t cut off, the H&S estimate is very similar to that reported by IMC. The Geostat report suggests that the Placer resource model of the mineralization was undertaken using the ordinary kriging method and was essentially "unconstrained". Unconstrained in this context means that the extension of the higher grade samples was not constrained by wireframe boundaries which purport to define the limits of the higher grade sample populations. The use of constraining wireframes around higher grade sample populations is a common practice in resource modelling in the mining industry, particular with the inverse distance and ordinary kriging estimation methods. It commonly leads to overestimation of the grade within the wireframe boundaries and underestimation of grade outside the boundaries. At the 0.5 g/t cut off, the total estimate of tonnage in the H&S model is significantly larger than the corresponding Geostat Estimate. The grade estimate is also higher. The H&S estimate of the indicated resource tonnage at 0.8 g/t is similar to that of Geostat at the same cut off grade but significantly higher in grade. In the opinion of H&S the primary reasons for these differences in tonnage and grade are the use of the tight wireframes to constrain the higher grade sample population in the model construction, and the sample grade cutting practices used by Geostat. Geostat used a cap of 25 g/t for all grades of one metre samples. The impact of this capping may be relatively insignificant in the smaller Botijas zone where the coefficient of variation of the grades is comparatively small but it is likely to have a greater impact in the larger Fortuna mineralized zone. Grade capping is generally not used with the application of the MIK method because the method has an inbuilt mechanism for controlling the extension of higher grade samples. Assuming that the grade capping and the tight wire framing are the main reasons for the differences between the Geostat estimates and the H&S estimates, it is reasonable to conclude that the interpretation of the continuity of the gold mineralization and/or the structures controlling the continuity is very important to the assessment of the resources in this deposit. In the view of H&S, there is insufficient geological and statistical support for the wireframe interpretation of Geostat to justify its use in modelling the Crucitas gold resources. Relogging of core carried out in 2007 by Infinito staff could not find geological evidence to support the use of these wire frame constraints. Recommendations H&S recommends a program of infill drilling at 25 metres spacing on the east-west drill sections for at least those resources to be accessed in the first two years of mining. This infill drilling will improve the quality of the resource estimates in this initial production period leading to better scheduling and reconciliations. The H&S estimate shows more than twice the volume of inferred resources as compared to the Geostat report. The Company intends to conduct a significant amount of drilling with the objective of bringing these inferred resources up to an Indicated status for conversion to probable reserves. Qualified Person The H&S resource estimate and the disclosure in this news release, including the material comparing the interpretations of the mineralization and the various resource estimates, have been prepared by or under the supervision of Neil Schofield, M.Sc. MAusIMM, MAIG, an independent Qualified Person under National Instrument 43-101. Mr. Schofield has consented to being named in this news release. Verification work in support of the resource estimate was completed by Moose Mountain Technical Services and was completed by, or under the supervision of, Mr. R. J. Morris, M.Sc., P.Geo., an independent Qualified Person under National Instrument 43-101. Mr Morris has consented to being named in this news release. Caution Regarding Forward-Looking Information and Statements Certain statements in this press release address future events and conditions and, as such, involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the statements. These factors include, among others, the inherent risks involved in the exploration and development of mineral properties, the uncertainties involved in interpreting drilling results and other geological data, fluctuating metal prices, the possibility of project cost overruns or unanticipated costs and expenses, uncertainties relating to the availability and costs of financing needed in the future, the possibility that all necessary governmental and regulatory approvals will not be received, and the availability of a qualified workforce and third party contractors necessary for the development and operation of a mine. The Company undertakes no obligation to update these forward-looking information or statements if circumstances or management's estimates or opinions should change. The reader is cautioned not to place undue reliance on forward-looking information or statements. John Morgan, President Infinito Gold Ltd. "The TSX Venture Exchange does not accept responsibility for the adequacy
CONTACT: Infinito Gold Ltd., Suite 220, 1010 - 1st Street S.W., Calgary,
2008-05-29 18:25:40 0373407 PRNEWSWIRE
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