Surface material at Mafube consists of weathering products of the sandstones, siltstones and mudstones of the Vryheid Formation. The top layer consists of reddish-brown sandy soil, with clayey sandy subsoil below.

Weathering is deepest in the south and west, and shallowest in the north and east, following the general trend of the topographic surface. The average depth is 9.9 m, reaching a maximum of 23.28 m.

The Mafube area is underlain by a sequence of sedimentary rocks of the Dwyka Group and the Vryheid Formation of the Ecca Group (Karoo Supergroup), which rest unconformably on an uneven floor composed of older gabbro and granodiorite (associated with the Bushveld Igneous Complex) as well as felsite of the Transvaal Supergroup.

The generally flat-lying Vryheid Formation consists of sandstone, siltstone, shale and coal seams. Strata at Mafube are typical of the Witbank Coalfield, with four of the five coal seams being present. Underlying the coal sequence of the Vryheid Formation are glacial deposits of the Dwyka Group, which accumulated on the erosional pre-Karoo basement surface.

The palaeotopography of the pre-Karoo basement largely controlled the deposition of the lower coal seams and partings.

The glacial deposits of the Dwyka Group vary within the project area and consist of fine-grained varved siltstone and shale to very coarse, matrix supported tillites. Clasts within the tillite are typically felsite from the Ro ........

The extraction of coal at Mafube is based on opencast mining methods currently focused in the Nooitgedacht area. The LoM plan is based on the extraction of coal from six opencast areas namely:
• Pit MGA;
• Pit MGB;
• Pit MGC;
• Pit MGD;
• Pit MGE; and
• Pit MGF.

Mining operations are based on a combination of contractor and owner-operated mining. Mining contractors were appointed to remove topsoil at an average thickness of 0.8 m and to remove the weathered burden material (softs) at a width greater than the strip width. This prevents the flow of soft over the hard overburden highwall and allows sufficient room for pre-split drilling activities. The presplit holes are drilled to the floor of the coal seam and production drilling to the roof of the coal seam directly below the hard waste burden. Pre-split drilling activities are designed to drill through the hard waste burden to the floor of the coal seam directly beneath. Once the presplit drilling and blasting is completed (conducted before burden drilling and cast blasting to avoid damage to the highwall of the pit), production drilling activities commence. Burden drilling and cast blasting is to the roof of the coal.

Blasted burden waste material is dozed down to a predefined level above the relevant coal seam. This level was pre-determined by a combination of burden thickness and coal seam thickness as contained within the “Dozer percentage” curve in the mine scheduling ........

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