Orezone Gold Corporation (TSX:ORE) has announced that gold mineral resources at its 100% owned Bomboré Gold Deposit located in Burkina Faso, West Africa have substantially increased to 60.9 million tonnes of indicated mineral resources at a grade of 0.81g/t for 1.6 million oz of gold plus 60.6 million tonnes of inferred mineral resources at a grade of 0.96g/t for 1.9 million oz.
"Bomboré is now the largest undeveloped gold deposit in Burkina Faso and it remains open at depth and along strike" said Ron Little President and CEO. "Orezone will immediately commence an aggressive infill and expansion drill program to further expand mineral resources in conjunction with completing a preliminary economic assessment."
The mineral resource update includes this year's 42,456m (619 holes) infill and expansion reverse circulation ("RC") drill program that was designed to upgrade and test the limits of the surface oxide resource. The program was successful and also served to increase the continuity and grade of the fresh rock resource below. This unexpected and material change to the total mineral resource warrants a change in the Company's approach to also consider developing the project as a carbon in leach ("CIL") operation. The deposit is still open on surface where more oxide material is targeted. However, the potential to significantly increase the fresh rock mineral resources at a grade of 1.0g/t or higher in the top 200m from surface is now an equally high priority. The Company's board of directors has approved a short term drilling budget of $2.5M to commence core drilling and to secure additional drilling equipment. As part of this budget, several kilometres of new surface targets will also receive RC drilling. Orezone intends to continue with its plan of completing a preliminary economic assessment of the project by the first quarter 2011. The assessment will now include both heap leach and CIL scenarios.
The mineral resources were estimated by the Company and audited by SRK Consulting (Canada) Inc. ("SRK"). The mineral resources are constrained within 4.3km² of conceptual optimized open pit shells (11km long and up to 1km wide) with an estimated stripping ratio of 2.2:1. Approximately 80% of the total resource occurs in the top 80m, but pit shells can reach a depth of 200m. Resources are totally open at depth and 90% of the drilling to date is within 60m of the surface. The pit shells are based on a US$1,025 gold price, relevant cost estimates for mining, processing, G&A, and detailed metallurgical results (reported December 2009) to estimate recoveries for a CIL plant scenario. The mineral resource model is based on a total of 120,605m of RC and core drilling data compiled up to August 2010. The project is situated beside the main highway just 85km east of the capital city of Ouagadougou. Infrastructure in the flat lying area is excellent with a low population density and access to power and water.
"With 35,000 ounces of gold per vertical metre in the top 60m of the deposit, there remains excellent potential to significantly increase resources at depth as we extend the definition drilling to a depth of 120m," said Pascal Marquis, V.P. Exploration for Orezone. "We have still not exhausted the surface oxide targets or the potential of lateral extensions to our current open pit shells which will also receive more drilling."
Several factors account for the difference between the 2010 and 2008 mineral resource estimates as follows:
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All 2010 drill samples were subjected to a Leachwell™ analysis where results higher than 0.2g/t were complemented with a fire assay of the leach residue. Many Leachwell™ samples from the previous 2008 estimate did not include leach residue assays for any sample with a leach grade below 0.5 g/t. The new expanded LeachWell™ residue assay database has been used to build a leach model that has been used to estimate the grade of the LeachWell™ residues for the samples that were missing this analysis, based on well defined leach curves for each of the major lithological units. The net effect was an increase of about 4% in the grade as the mineral resource is now more representative of the in-situ grade;
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The drilling defined several higher grade zones (> 0.5 g/t) within the large lower grade envelop of the deposit. These zones were modeled separately and as a result have contributed significantly to higher grades. In the 2008 estimate, only low grade envelopes were used, with a top cut of 4 g/t for all of the composited assays. In 2010, the composite grades were capped at 1.44, 4.05 and 8.07g/t in the low grade, laterite and high grade zones, respectively.
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Ordinary kriging was used versus inverse distance squared kriging in the 2008 estimate.
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A higher gold price of US$1,025 was used in this estimate versus US$800 in 2008.
Drilling on the Bomboré property and the mineral resource estimates were supervised by Pascal Marquis, Ph.D., P. Geo., Vice President and Qualified Person for Orezone as defined by National Instrument 43-101 and who has reviewed and approved the technical information in this release. The mineral resource estimates were prepared by Orezone and audited by Dorota El-Rassi, P.Eng. and Glen Cole, P.Geo. of SRK who are Independent Qualified Persons as defined by National Instrument 43-101. Orezone holds a 100% operating interest in the project while the government of Burkina Faso will receive a 3% net smelter royalty and a 10% non-participating (carried) interest should the project go into production.
The Company also announces that Mr. Joseph McCoy has been appointed Chief Financial Officer. Joe holds an MBA and Bachelor of Commerce degree from Concordia University and a project Management diploma from McGill University and brings over 25 years of financial and operational experience to Orezone. Joe replaces Mr. Sean Homuth who has departed to pursue other opportunities. Orezone would like to thank Sean for his dedication and contributions during his tenure.
Source: Orezone Gold Corporation