The geomorphology and aeolian deposits in the vicinity of Florisbad
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The discovery of the Florisbad hominid prompted further archaeological and palaeoanthropological research in the Florisbad area. However, research that looks specifically at the geomorphology and aeolian deposits around Florisbad has been very limited, although aeolian processes and sand dunes have been widely recognized as being of significance in understanding past environmental conditions in this area. Geologists have also shown an interest in trying to explain the formation of the Florisbad spring and fossil site. The Florisbad spring site has a complex stratigraphy because the deposits are lithologically variable due to the fact that they are the product of an unusual depositional environment. Many hypotheses have being proposed in trying to understand the complex depositional environment at Florisbad. This research suggests that, in order to better understand the complex depositional environment of Florisbad, there is a need to understand the surrounding geomorphological setting in terms of geohydrological and geomorphic processes and features. The methodology comprises a review of current literature on lunette dunes, and previous work undertaken on the geomorphology and geology at and around Florisbad, an examination of aerial photographs to identify lunette dunes in the vicinity of Florisbad, and fieldwork to ground-truth the dunes. Field sampling, laboratory work (sedimentological techniques, pH, conductivity and geochemical analysis) as well as statistical analyses (principal component and cluster analyses) were employed to compare the characteristics of the lunette dune sediments with those at the spring site itself, and to assist in a general palaeoenviromental reconstruction.The results of the laboratory analyses do not reveal any obvious differences with respect to sediment particle size and pH, between the lunette dunes and the spring site. However it was noted that there were minor differences when it came to dune structures, electrical conductivity and chemical composition. There is convincing evidence that the sediments are primarily wind-blown in origin. The geochemical results suggest the lunettes are older than the dune at the spring site. Two optically stimulated luminescence dates were determined for a lunette dune close to Florisbad. The samples were dated to 500 years, and it is suggested that this is because of reworking of sediments down the slope. The overall geomorphology, as described in this study, suggests a shallow depression (Florisbad-Soutpan) in which both fluvial and aeolian processes have conspired to create a unique landscape which has promoted the formation and preservation of dune deposits and the unique archaeological site which is Florisbad.