Bauxite Resources Limited is grade drilling in its Western Australian Darling Range tenements to firm up resource definition and to develop mine plans._x000D_
The Darling Range bauxite is generally in shallow deposits with minimum overburden. In the northern tenements, the ore is characterised by a higher silica layer which may extend from 0.5 to 1.5 m below, which high grade bauxite is found to a depth of four to 7 m._x000D_
When grade drilling samples are taken, every 0.5 m and the recovered sample is weighed, logged and bagged. To eliminate splitting errors, the whole sample over the short interval is pulverised._x000D_
Twinning holes variations are observed when using various drill rigs. Diamond core has been shown to give close to 100 per cent recovery and grades have been verified by digging bulk samples. As such, diamond core is used as the reference._x000D_
It is intended to include sonic drilling as an alternative to diamond cores._x000D_
This presentation details and attempts to explain the reasons for the observed variations in the various drilling methods used by Bauxite Resources Limited.This is an ABSTRACT ONLY no paper was prepared for this presentation.