World Mining Exploration News

Vista Provides Update on Exploration and Metallurgical Testing Results at the Mt. Todd Project in NT, Australia

Vista Gold Corp. (TSX & Amex: VGZ) (”Vista” or the “Company”) is pleased to provide an update on activities underway at its Mt. Todd Project in the Northern Territory, Australia. The Company is currently conducting technical programs that management expects will lead to the completion of a preliminary feasibility study by the end of the year.

Part of this year’s program is a diamond core drilling program totaling approximately 7,000 meters in 14 holes to obtain further information about the size and quality of the mineral resource. The program is designed to increase the sampling density to support the conversion of inferred gold resources to measured and indicated resources at depth, and to explore for additional resources down dip. In a press release dated February 27, 2008, Vista reported an updated gold resource estimate including the results of a 25 hole program that resulted in an increase in measured resources(1) of 769,633 ounces of gold and an increase in indicated resources(1) of 367,686 ounces of gold resulting in a combined increase in measured and indicated resources(1) of 1,137,319 ounces of gold at a cut-off grade of 0.015 ounces of gold per ton. These estimates (as reported in Vista’s February 27, 2008 press release) are shown below.

<< Metric Average Average Resource Tonnes Grade Short Tons Grade Contained Gold Classification (x1000) (grams/tonne) (x1000) (ounces/ton) Ounces (x1000) >>
<< Measured (1) 43,543 0.96 47,987 0.028 1,346 >>
<< Indicated (1) 45,746 1.05 50,425 0.031 1,549 >>
<< Measured & Indicated (1) 89,280 1.01 98,413 0.029 2,895 >>
<< Inferred (2) 58,816 0.81 64,832 0.024 1,532 >>

The current drilling program began in April 2008, and is continuing under the direct supervision of Tim Tuba, Vista’s Exploration Manager in Australia. The core drilling is being completed by Boart Longyear Australia Pty Ltd, with the sample preparation being completed by ALS Chemex in Adelaide, South Australia, followed by assaying for gold by ALS Chemex in Perth, Western Australia. A sample quality control/quality assurance program has been implemented and check assaying is being done by Genalysis Laboratory Services Pty Ltd in Perth. Multi-element analyses, including copper, are being done by ALS Chemex, also in Perth. All holes were angle holes drilled to intersect mineralization at close to right angles; however, due to physical constraints and the complex nature of the deposit, true thickness of the drilled intervals cannot be assumed from the measured intercepts. Sampling and assaying methods are being conducted in accordance with the CIM Mineral Exploration Best Practices Guidelines. All samples taken were one meter in length, except the last interval of the drill hole.

At present, eight holes have been completed with gold assays received for the first hole drilled. Currently, the time from shipment of the sawed drill core until receipt of assays is approximately 55 days, which is longer than expected but reflects actual turnaround times currently experienced. The assays include the following highlights :

<< Assay Assay Drill Hole Interval Intercept (grams/ Including Intercept (grams/ (meters) (meters) tonne) (meters) (meters) tonne) >>

The assay analysis has been completed by ALS Chemex in accordance with industry accepted standards and has been reviewed by Tim Tuba, P. Geo. as the qualified person under NI 43-101.

A metallurgical test program is also designed to determine the processing parameters for the project. Initial test work by the Company indicated that it may be possible to recover the copper by flotation into a concentrate containing both gold and copper and by leaching the cleaner tail to recover gold, and subsequently, produce a gold bullion product. The Company is also investigating technology to reduce the cost and energy required to grind the hard Mt. Todd ore. Vista has recently completed a program with Polysius Corp., of Beckum, Germany, to evaluate the effectiveness of crushing and grinding of the ore using high pressure grinding roll (HPGR) technology compared with a conventional crushing, semi-autogenous grinding and ball mill grinding circuit. The results of this testing have been reviewed by Deepak Malhotra of Resource Development Inc. of Wheat Ridge, Colorado, a consulting metallurgist and qualified person. The tests indicate that the use of this technology in the crushing/grinding circuit has the potential to reduce energy requirements by approximately 9.5 kWhr/tonne, which at an estimated power cost of US$0.12 per kWhr represents a savings of US$1.14 per tonne treated, when compared to the use of a conventional crushing, SAG and ball mill grinding circuit. Metallurgical tests using samples generated from the HPGR tests have been completed, with assay results pending.

For more information on the resource estimates completed on the Mt. Todd Project, please refer to Vista’s January 4, 2007, February 27, 2008 and April 24, 2008 press releases, or to the completed technical studies, all of which have previously been filed on http://www.sedar.com and may also be found on Vista’s website at http://www.vistagold.com.

Fred Earnest, President and COO stated, “The drilling results obtained thus far support our belief that the Mt. Todd ore body continues at depth with higher assay values than those encountered in shallow drilling. The drilling program is proceeding from the south to the north and will test the down-dip extension of the heart of the ore body as identified by last year’s drilling.” He continued, “We believe that the HPGR test results represent a significant breakthrough in processing the Mt. Todd ore. We expect the reduction in power costs to have a significant impact on the results of the preliminary feasibility study that we intend to undertake at the conclusion of the drilling program. It is unfortunate, but unavoidable, that the results of the drilling and metallurgical test programs are currently being delayed by slow turnaround of assay results from laboratories in the US and Australia.”