The ECC complex comprises the Dorstfontein, Forzando and Tumelo operations.

Dorstfontein geology.
Coal measures of the Highveld and Witbank coalfields are hosted in the Ecca Group, which includes the Vryheid and Volksrust coal-bearing formations. All coal seams in the ECC area are hosted in the Vryheid formation which ranges in thickness from 80m to 300m. There are five major coal seams present in the area, named from the base upwards as S1, S2, S3, S4 and S5.

A granitic basement high, which forms part of the Smithfield Ridge and is referred to below as the Central plateau, divides the DCM complex into two separate geological domains and the western and eastern limbs can be found on either side of this plateau. S1 is only developed in the central portions of the paleo-valleys, ranging in thickness from 0.1m to 2.5m. Underground extraction of this seam is considered uneconomic due to its highly variable thickness, inferior quality, isolated occurrence and coal devolatilisation. In the DCM complex, seam splitting is generally a provenance of detrital material resulting largely from the proximity of the seam to the Smithfield Ridge and, as a result, the S2 and S4 are further subdivided into S2L, S2U and S4L and S4U, respectively.

S2L is thinnest over palaeo-highs and thickest over troughs of palaeo-valleys. Two S2L thickness domains exist in the complex. In the west (DCMW), seam thickness ranges from 0.1m to 5m and, in the east (DCME) from ........

The ECC complex comprises the Dorstfontein, Forzando and Tumelo operations.

Dorstfontein complex.
Dorstfontein complex forms part of ECC and is on the northern margin of the Highveld coalfield along the boundary of the Smithfield Ridge, the boundary between the Highveld and Witbank coalfields.

It is 36km south of the town of eMalahleni and, to the south-west, the property borders the town of Kriel. It is in the Highveld magisterial district, under the jurisdiction of the eMalahleni local council, Mpumalanga, South Africa. Operations can be reached via the hard-topped R544/R547 roads linking the towns of Witbank and Kriel. It is surrounded by mineral right tenure owned by Kusile Mining to the west, the Universal Coal New Clydesdale operation to the north, the Kriel East operation to the south and Mbuyelo Coal to the east.

The complex covers a total rights area of 7 892ha comprising the underground Dorstfontein West mine and opencast and newly developed underground mine at Dorstfontein East mine. Seams being exploited are mainly S4 divided into S4 upper (U) and S4 lower (L) and S2 divided into S2U and S2L. The Dorstfontein West operation is exploiting the S4L through an incline development from the historical S2 workings with three production sections. A new development at Dorstfontein East is the implementation of an underground mine exploiting S2 through two adits accessed from one of the open pits. Dorstfontein East is the only opencast ........

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