Grootegeluk mine is in the Waterberg Coalfield, which has an east-west striking length of some 88km, complemented by a north-south width of around 40km, and lies in South Africa, extending westward into Botswana. The Waterberg Coalfield is fault-bounded along its southern and northern margins and can be referred to as a graben deposit, with the Eenzaamheid fault forming its southern limit and the Zoetfontein fault forming its northern limit. The Daarby fault, with a downthrow of some 350m towards the north-east, divides the Coalfield into a deep north-eastern portion and a shallow south-western portion. The upper part of the coal deposit, the Volksrust formation (some 60m thick), comprises intercalated mudstone or carbonaceous shale and bright coal layers. It displays a well-developed repetition of coalshale assemblages that can be divided into seven discrete sedimentary cycles or zones (zone 11 – zone 5).

The Vryheid formation (roughly 55m thick) forms the lower part of the coal deposit and comprises carbonaceous shale and sandstone with interbedded dull coal seams varying in thickness from 1,5m to 9m. Due to its nature, the Vryheid formation is classified as a multiple-seam deposit type. There are five coal zones in the Vryheid formation, predominantly dull coal, with some bright coal developed at the base of zones 2, 3 and 4.

Grootegeluk is a surface coal-mining operation where a series of parallel benches are advanced progressively across the deposit via a process of drilling, blasting, loading and hauling with truck-and-shovel fleets.

Mining-bench definitions coincide with the geological boundaries of the layered coal deposit except for the uppermost bench, bench 1A overburden, which is designed at a practical level above the first fresh coal. The coal deposit has been subdivided into geological units based on the unit’s physical and chemical properties, to form 14 mining benches for both saleable products and waste. In this way, the run-ofmine for each bench is reserved for particular beneficiation destinations to produce products with specific coal characteristics and at given quality-control specifications.