4. GEOLOGICAL MODELLING

The Freestate mining complex and Elandskraal, Evander and Randfontein are all mature mining operations that have been in operation for many years. Consequently, the latest declaration of mineral resources was based on a thorough understanding and interpretation of the geology, based upon the experience and information obtained during the many years of mining, supplemented by the information available from surface boreholes and adjacent mines.

For the purposes of geological interpretation, and to define areas of reasonable similarity for geostatistical analysis, each mine section is subdivided into coherent geozones. Typically, each mine section may have five to ten geozones bounded by major faults, distinct changes in sedimentological faces and less distinct boundaries defining areas where there is a noticeable regional change in the general grade of the reef.

Each mine’s mineral resources are categorised, blocked out and ascribed an estimated value. Typically measured and indicated resource blocks are aligned in the direction of mining. The blocks comprise the length of a mining panel (20 to 30 metres) and extend beyond the mine workings to a distance that is equivalent to three months’ mining.

Consequently, these blocks are typically 30 metres long and 30 metres wide, although at Evander there are some substantially larger blocks defined along pay channels. Beyond the indicated blocks, large inferred blocks are defined up to the mine boundary.