the north–south striking De Bron Fault. This major structure has a vertical displacement of about 1500m as well as a lateral shift of 4 km. A number of other major faults lie parallel to the De Bron Fault. Dips occur mostly towards the east, averaging 30 degrees but this becomes steeper approaching the De Bron Fault. To the east of the fault, a dip occurs towards the west at 20 degrees, although structurally complex dips of up to 40 degrees have also been measured. Between these two blocks, lies the uplifted horst block of the West Rand Group of sediments with no reef preserved. The western margin area is bound by synclines and reverse thrusts faults and is structurally complex. Towards the south and east, reefs sub-crop against overlying strata, eventually cutting out against the Karoo to the east of the area. Most of the ore resource tends to be concentrated in reef bands located on one or two distinct unconformities. Mining has taken place as mostly deep-level underground, exploiting the narrow, generally shallow dipping tabular reefs. Basal Reef The Basal Reef, is the most common reef horizon. It varies from a single pebble lag to channels of more than 2m thick. It is commonly overlain by shale, which thickens northwards. Leader Reef The second major reef is the Leader Reef, located 15-20m above the Basal Reef. This is mostly mined at shafts to the south. Further north, it becomes poorly developed with erratic grades. The reef consists of multiple conglomerate units, separated by thin quartzitic zones, often totalling up to 4 metres thick. A selected mining cut on the most economic horizon is often undertaken. The B Reef is a highly channelised ore-body located 140m stratigraphically above the Basal Reef. Within the channels, grades are excellent, but this falls away to nothing, outside of the channels. The A Reef is also a highly channelised reef, located some 40m above the B Reef. It consists of multiple conglomerate bands of up to 4m thick and a selected mining cut is usually required to optimise the ore-body. Fossils of Matjhabeng A 2007 palaeontological study done in greater Matjhabeng began a programme of excavation of an early Pliocene locality. With an estimated age of 4.0–3.5 Ma, the locality also represents the only well-documented, river-deposited Pliocene locality in the central interior of southern Africa. After three years of excavation, a diverse fauna that