Area of the Greenside Colliery is underlain by rocks of the Karoo Supergroup comprising sedimentary rocks of the Carboniferous Dwyka Group and the Vryheid Formation of the Permian Ecca Group. The diamictites of the Dwyka Group were deposited in a grounded glacial setting and the mudrocks, coals and sandstones of the Vryheid Formation were deposited in a delta plain depositional environment. The coarse grained diamictites of the Dwyka Group, which are positioned well below surface in the study area, are unlikely to contain fossils and in any case will not be exposed by the development. The overlying rocks of the Vryheid Formation of the Ecca Group are renowned for their wealth of plant fossils of the famous Gondwanan Glossopterus flora which has been described from Permian-aged rocks. This flora is the source of the coal which is mined from the Vryheid Formation in South Africa. Within the Vryheid Formation there are occurrences of well-preserved elements Glossopteris flora comprising wood and/or leaves.

Due to the fact that Greenside Colliery utilises underground mining methods, most surface infrastructure is associated with activities relating to the handling of coal thereafter.

Although Greenside Colliery has 18 shafts located within their mining rights area, only Cairns and No. 6 shafts are operational. Coal is extracted using the continuous miner method (previously bord and pillar) and is brought to the surface via conveyors to the coal beneficiation plants.

Although historically the No.1, 2, 4 and 5 seams have been mined at Greenside Colliery, only the No.4 seam is currently mined within the Greenside Colliery minerals rights boundary. Greenside Colliery produces coal for both the export and local markets. The No.4 seam is mined using continuous mining methods.

The only operational shafts on the mine site are the Cairns and No. 6 Shaft. Only ventilation shafts will be constructed for the Extended No.4 seam underground workings. As access will be obtained from existing underground operations, no additional access shafts will be required for the mining of the No.4. seam for the Landau and Kleinkopje coal reserves. As no blasting is conducted on the surface and blasting is only conducted underground as part of the Colliery Training College section (CTC) surface structures are not affected by blasting.

Surface subsidence could form within No. 5 seam stooped areas. Dry land cultivation is taking place over most of these areas. Localised surface subsidence, resulting in impaired surface drainage and associated ponding areas is very limited. Measures will be taken to remediate subsided areas and allow beneficial land use to proceed. A rock engineering study was undertaken to determine the adequate pillar safety levels to ensure that no surface subsidence will be incurred as a result of extended underground mining operations of the No.4 coal seam reserves. No surface structures are affected by the No. 5 seam stooped areas and as indicated above, surface drainage has largely been reinstated.

Two coal beneficiation plants are located on the Greenside Colliery mine site. The No. 4 seam plant currently processes an average of 435000 tons of coal per month from 4 seam 4A.

No.4 seam Plant.
The ROM coal is conveyed via 4A conveyor to surface. The plant has 4 surface conical ROM stockpiles:
- 4A, 4S1, 4S2, and 4S3 with underground withdrawal conveyors and Nick Shaft stockpile with 2 surface reclaim conveyors fed by front end loaders.

Coal from 4A conveyor is fed to a flopper that diverts coal to the 4A stockpile or onto 4S1 conveyor. 4S1 conveyor discharges coal via a flopper onto 4S1 or onto 4S2 conveyor. 4S2 conveyor discharges coal onto 4S2 stockpile or 4S3 conveyor. 4S3 conveyor feeds coal to Nick shaft stockpile.

4S1 and 4S2 stockpile feed Module1&2 only. 4A stockpile feeds Module 3 & 4 but can also feed Module1 & 2 bypassing Module3&4. In the past Module4 is the tertiary crushing of ROM coal to minus 25mm for Rooiwal power station ........