Late Pleistocene wetting and drying in the NW Kalahari: an integrated study from the Tsodilo Hills, Botswana

The sediments and landforms at the Tsodilo Hills, in the northwestern Kalahari desert, provide an opportunity to directly investigate the late Quaternary wetting and drying of the region from evidence at a single site. Lacustrine carbonates, including incorporated molluscs and diatoms, a lake shoreline feature and stabilised linear dunes were investigated for their constituent palaeoenvironmental signals. Chronometric control is provided by calibrated C-14, AMS and OSL dating. The evidence suggests that linear dune construction has not occurred since the Last Glacial Maximum, with particular development from 36 to 28 ka. Lake stands indicating wetter regional conditions than present occurred at 40-32 ka, with more seasonal conditions from 36 ka, and at 27-12 ka with a possible drying out at 22-19 ka. Data are consistent with other independent studies from the region, and with recent evidence obtained from Atlantic cores off the coast of Namibia. It is concluded that careful consideration of multi-proxy data from a single location can assist in resolving discrepancies that arise from independent studies of lake, cave and dune records in the Kalahari