Greenside colliery is located in the Witbank Coalf ield where f I've coal seams are present. These consists of, from bottom, the No 1 Seam, sequentially to the No 5 Seam at the top, with inter-seam partings consisting of mainly shale or siltstone and sandstone, with thicknesses ranging between 1.5 m and 23 m. The No 4 Seam is currently the only contributor to the colliery’s export product.
The colliery is sub-divided into two distinct domains, by a major northwest, southeast trending normal fault system with a measured maximum throw of 30 m in the southeast. The throw gradually
decreases to a ~1 m throw towards the northeast. Mining has been constrained by the fault system, with development from the east and west, stopping on approaching the fault zone. Several dolerite dykes have been identif ied by drilling and mining, but the impact on mining is limited to occasional cases of poor ground conditions experienced during mining.
Surface material at Greenside consists of weathering products of the sandstones, siltstones and mudstones of the Vryheid Formation, with isolated patches of dolerite in the southwestern part of the GAR. The top layer consists of reddish-brown sandy soil, with clayey-sandy subsoil below.
Weathering generally does not extend deeper than approximately 12 m at Greenside, except where adjacent to dolerite dykes and close to surface water bodies. In these instances, weathering may reach up to 17 m below the surface. Weat ........
