Mar 1 2011
Riverstone Resources Inc. (TSX VENTURE:RVS)(FRANKFURT:3RV) has received an independent resource estimate, which shows a substantial increase in the gold mineral resources at its flagship Karma project in Burkina Faso, West Africa.
The NI 43-101 compliant resource estimate has increased the contained ounces of gold by 70% from the Company's initial estimate of May 2009. The total discovery cost of the increase in resources was less than $6 per ounce of gold.
HIGHLIGHTS
- Indicated gold resources are 810,600 ounces of gold in 22,845,000 tonnes at a grade of 1.10 g/t.
- In addition, the inferred gold resources are 1,119,100 ounces of gold in 44,110,000 tonnes at a grade of 0.79 g/t.
- The gold resources are at shallow depths and over 90% of the gold resource is within 150 metres from surface.
- Mineralization remains open at depth and along strike.
- The resource estimate only includes drill hole results received up to October 2010 and results of an additional 13,000 metres of drilling, completed since that time, are not included. Most of the newest drill results include significant mineralized intervals. Data from this and on-going drilling will be incorporated into the next resource estimate.
- The prospective Nami deposit drill results have not been included in this resource estimate.
- This is an interim estimate and will be updated again later in the year.
Michael D. McInnis, President and CEO of Riverstone Resources commented, "We are extremely pleased with the material increase in the gold resource at Karma. There is ample room to increase the gold resource and to establish Karma as one of the premier gold projects in West Africa. We are presently drilling with two rigs and plan to add up to three more rigs as they become available."
The Karma project consists of four separate deposits, which are located close to each other.
The mineral resource was estimated by independent consultants John A. Zbeetnoff, P.Geo., and Giles R. Peatfield, Ph.D., P.Eng. The geological interpretations for the four deposits modelled in the 2010 Karma Resource estimate were completed using a base case of a nominal 6 metre minimum drilled length and a nominal assay cut-off grade of 0.25 g/t gold. The interpretations outlined multiple mineralized bodies in each deposit. Each mineralized body was created as a wireframe and these were ultimately used as hard boundaries to limit grade interpolation.
Grade modelling was completed using 2.0 metre composites and an Inverse Distance Cubed ("ID3") formula. Composite grades were determined with length weighted capped and un-capped assay values. Capping levels were deposit specific and ranged from 12 to 22 g/t gold. Bulk density values used for the tonnage factor were 2.00 for oxide and 2.75 for sulphide resources.
The search ellipse orientation for each mineralized body was determined by manually contouring the pierce point values represented by the mathematical product of the grade multiplied by the true thickness for each hole that pierced the wire frame. These contours were generated on either vertical or inclined longitudinal sections.
All reported resources fell within the limits of the mineralized wire frames. All blocks or partial blocks within a wire frame needed to have at least three holes within 50 metres to be classified as Indicated Resource. Inferred Resources were determined from the remaining blocks, or partial blocks that lie within the wire frames and within 50 metres of a drill hole.
Each deposit was modelled in a unique partial block model project in Gemcom Software.
Assay data included in the estimates have been independently verified from original assay reports.
Source:
Riverstone Resources Inc.