Holocene landslides in KwaZulu-Natal, South Africa

The devastating impact of landslides and secondary instability with their unconsolidated depris deposits due to weathering, settlement and groudwater seepage are significant geological threats. Mass movemets can impact negatively on urbanisation and represent a critical factor determining landuse zonation during town and regional planning. Mapping and classification of mass movement deposits in the KwaZulu-Natal Province highlighted the more widespread extent of there Quaternary geomorphic desepquilibrium indicators than is commonly appreciated. Many of the largest occurrences mapped are palaeo-landslides located in areas of high rlief and steep slopes in the Ukhahlamba-Drakensberg footlopes and the major fiver valley. Some of these events temporatily blocked river channels resulting in changed channel and floodplain morphology. However, the majority of the landslides identified are smaller, more, recent, localized occurrences associated with high intensity rainfall events. Accelerator Mass Spectormetry (AMS) or radiocarbon dating of bulk organic material derived from ponds on back-tilted surfaces (sag ponds) of the palaeo-landslides has yielded minimum ages for the landslide events.