Ground-penetrating radar analysis of the Drimolen early Pleistocene fossil-bearing palaeocave, South Africa

The cave systems of the Malmani Dolomite, Gauteng, South Africa, have over the decades yielded numerous specimens of Pliocene to early Pleistocene hominin fossils which are critical for our understanding of human evolution. The geomorphological and geological context of these fossils is complex. An understanding of cave formational processes coupled with effective surface and subsurface mapping of different strata and soil depths has the potential to provide new insights. A technique that has not previously been employed to the fossil sites of South Africa is the use of ground-penetrating radar (GPR). Applied in combination with ground-truthing data from excavations and 3D scanning and photogrammetry the combined technique highlights the capacity for GPR to help characterise various deposits. Results indicate the potential of the method to identify new void spaces, depth of colluvium as well as mapping structurally important chert bedding. This paper focuses on the Paranthropus and early Homo-bearing cave complex of Drimolen but highlights the potential for applying these methods throughout the region.