The data is all historical data obtained from BHP Billiton. BHP geologists log and sample according to the SANS 2004 guidelines and furthermore all recent exploration drilling used geophysical down-hole wire-line logging to guide the sampling process. The coal seams are relatively flat lying or slightly undulating with a south westerly dip. The average depth to coal of the north is 320m, west is 340m and the south 380m, becoming more than 500m deep at the southern extreme of the area. Four coal seams occur in the Theunissen coal field. The number 4 seam is the uppermost seam and the number 1 seam forms the lower most portion of this multi seam deposit. The number 4 and 3 seams are the only seams with economic importance as they are more consistent in terms of quality and thickness throughout the coalfield. The other seams are restricted to small isolated areas and have thickness and quality constraints.
The geological model was built by an independent registered geologist using Rockworks software. Contour maps were used to select a block for preliminary modelling and selection of a potential target areas. The BHP Billiton coal seam numbering was used in the seam naming for Africary Resource model. The Rockworks seam models were interpolated using Inverse distance for Thickness & Surface and Planar for trend. The Rockworks seam model was limited to a 5% cut off distance from a “point of observation”.