Paper 4: Ore Reserve/Resource estimation methodologies at Elura mine

The Elura Reserve/Resource Estimation has traditionally been done using an inverse distance squared algorithm with a drill spacing of 20mE x 20mN x 40mRL used to define measured resources. Wireframes are constructed for each ore type, which is defined on the basis of metallurgical characteristics and density. Each individual ore type is reported separately in the reserve. Mining in the Northern Pods commenced in August 1997 and milled grades for this mineralisation were quite different from those estimated from the Resource Model. This has meant a rethink of drill spacing and estimation techniques used at Elura.