ESR DATING EVIDENCE FOR EARLY MODERN HUMANS AT BORDER CAVE IN SOUTH-AFRICA

THE archaeological and hominid site of Border Cave (KwaZulu, South Africa) has a stratigraphie sequence covering the Middle and Later Stone Ages (MSA and LSA)1-10. It has been proposed that four hominid specimens recovered there (BC1 and BC2 of uncertain provenance, and BC3 and BC5 recovered from MSA layers) represent very early examples of anatomically modern humans, supporting an early late-Pleistocene appearance of modern Homo sapiens in Africa. This early appearance, however, has been questioned, largely because of doubts about the stratigraphic positions associated with the specimens and because of the lack of a reliable chronology for the stratigraphie sequence. We now report on the first comprehensive radiometrie dating analysis of Border Cave, using electron spin resonance (ESR) on teeth within sediment layers. BC3 is likely to be ∼70-80 kyr old, and BC5, 50-65 kyr old. BC1 and BC2 are almost certainly less than 90 kyr old. These results, although younger than some age estimates, support the early occurrence of anatomically modern humans at Border Cave. In addition, our results suggest that the Howiesons Poort lithic industry (∼45-75 kyr) and the MSA-LSA transition (∼35 kyr) are younger than often believed. © 1990 Nature Publishing Group.