2022-07-20 PLOS ONE 2022 17(卷), 7(期), (null页)
Detailed, well-dated palaeoclimate and archaeological records are critical for understanding the impact of environmental change on human evolution. Ga-Mohana Hill, in the southern Kalahari, South Africa, preserves a Pleistocene archaeological sequence. Relict tufas at the site are evidence of past flowing streams, waterfalls, and shallow pools. Here, we use laser ablation screening to target material suitable for uranium-thorium dating. We obtained 33 ages covering the last 110 thousand years (ka) and identify five tufa formation episodes at 114-100 ka, 73-48 ka, 44-32 ka, 15-6 ka, and similar to 3 ka. Three tufa episodes are coincident with the archaeological units at Ga-Mohana Hill dating to similar to 105 ka, similar to 31 ka, and similar to 15 ka. Based on our data and the coincidence of dated layers from other local records, we argue that in the southern Kalahari, from similar to 240 ka to similar to 71 ka wet phases and human occupation are coupled, but by similar to 20 ka during the Last Glacial Maximum (LGM), they are decoupled.
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