Selected outcrops of the Upper Devonian to Lower Carboniferous, Witteberg Group, Cape Supergroup were mineralogically and structurally analyzed. The study area is located approximately 30km northwest of Kirkwood and 10km south of Darlington Dam, Eastern Cape, South Africa. Strata predominantly consist of arenaceous Witpoort Formation, which includes the Perdepoort, and Rooirand Members. The Perdepoort Member is a thinly bedded quartzite also known as the "white streak". The Rooirand Member quartzite is a highly iron stained red-brown quartzite. The dark-grey, pyritic rich shales of the Kweekvlei Formation overlie the Witpoort Formation in the southern half of the study site. These shales are highly deformed and display closely spaced thrust faults and close folds. The study area encapsulates a range of folding from tight to open folds. Faulting consists of low angle north verging thrust fault, south verging back thrusts, south and north dipping normal faults, and strike-slip faults. Closely spaced, fore-land verging thrusts faults predominate over hinterland verging back thrusts. Normal faulting post-dates thrust faulting and utilized weaknesses in axial planar cleavage and in certain instances existing thrust fault planes. Strike-slip faulting post-dates thrusting and has in places reactivated pre-existing thrust fault planes. Macro scale folding includes overturned synclines and large anticlines which have been eroded, exposing older strata. Fold axes plunge at low to moderate angles west-southwest. This correlates with tension gashes which indicate north westward directed forces. Eastward directed forces are confirmed by the presence of tension gashes and strike-slip movement. The local geology displays north westward directed compression followed by strike-slip movement. Normal faulting post-dates all other structures and is associated with the Mesozoic break-up of Gondwana. The Perdepoort Member was sampled along strike, at different outcrop latitudes. Seven samples were selected for scanning electron microscope analysis. Samples are composed almost entirely of quartz; accessories include, biotite, muscovite, sericite, baryte, and apatite. Epigenetic hematite is present along cracks within certain samples Epigenetic hematite occur along cracks with oxides and phosphates in the form of rutile, apatite and monazite present in a number of samples. When compared to other silica extraction operations the Perdepoort Member appears viable for explotation. However, for the solar cell industry the purity of this horizon is clearly far below that required for industy.

The vegetation supported by the Witteberg and Dwyka Groups south of Worcester is a diverse mosaic of fynbos-, renosterveld- and succulent karoo vegetation units sustained by a winter-rainfall pattern. Elytropappus rhinocerotis (renosterbos) dominated plant communities are found on finer grained soils derived from the various mudrock-dominated formations of the Witteberg Group, a Passerina truncata (gonnabos) dominated shrubland with large Protea shrubs and / or small Protea trees where the substrate is largely influenced by the sandstone-dominated formations of the Witteberg Group, a grass dominated Capeochloa arundinacea (Olifantgras) shrubland where both mudrock-dominated and sandstone-dominated formations influence the substrate as a result of folding, a karoo Hirpicium integrifolium (Haarbossie) dominated shrubland where succulents are in abundance on the Dwyka tillite, and a distinct Thamnochortus bachmannii restio-dominated sandveld in areas where deep aeolian sand had accumulated. The differences in vegetation communities are mainly based on geology with consequent soil characters and degree of rockiness, as well as topography, moisture availability and the water holding capacity of the soil. Although slope, aspect and elevation can sometimes be associated with specific plant communities, geology, soil pH and rock cover are the principal elements responsible for shaping the vegetation mosaic. Rather than a broad ecotone, the vegetation of the study area is understood as a complex mosaic mountain vegetation entity. / Environmental Sciences / Ph. D. (Environmental Sciences)