A Geostatistical study of the copper orebody within the Phalaborwa complex

Abstract

This Report makes a geo-statistics comparison between Benches 10 and 20 of the Palaborwa open pit and presents a suite of geo-statistics programmes developed for the Sinclair Spectrum personal computer. It has always been assumed for planning and grade control purposes, that values in one bench can be extrapolated into the bench below and this is an attempt to validate the assumption. Assays are done on drill chip samples from every blastnole drilled in copper bearing composites; the values are then recorded by position on 1:500 scale Bench Plans. These data are regularised by averaging values within 10m x 10m blocks which are then used in the geo-statistics analysis. A three parameter lognormal model was used to represent the distribution; the two benches were compared with each other in the analysis through to Kriging of each central area. Although the benches were found not to have the same distribution there is a high degree of similarity and the use of geo-statistics would improve the accuracy of grade predictions.