Abstract
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 ~3 ka. Three tufa episodes are coincident with the archaeological units at Ga-Mohana Hill dating to ~105 ka, ~31 ka, and ~15 ka. Based on our data and the coincidence of dated layers from other local records, we argue that in the southern Kalahari, from ~240 ka to ~71 ka wet phases and human occupation are coupled, but by ~20 ka during the Last Glacial Maximum (LGM), they are decoupled.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Aged, 80 and over
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Archaeology*
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Botswana
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Fossils
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Humans
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Occupations
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Thorium / analysis
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Water*
Grants and funding
Funding for this project was provided by the Department of Science and Technology National Research Foundation (DST-NRF, South Africa) Centre of Excellence in Palaeosciences through student bursaries (JvdM and WK) and Operations grants - CoE2017-065, COE2018-05OP, COE2019-OP17 and COE2018-10OP (JWi and RP); the National Research Foundation (NRF, South Africa) African Origins Platform Grant - AOP150924142990 (RP), NRF (South Africa) Competitive Programme for Rated Researchers -120806 (RP), National Geographic Society - Waitt Grant (BJS), University of Cape Town VC2030 funding (RP), NRF (South Africa) Research Development Grant for Y-rated Researchers (JWi), and Australian Research Council Discovery Early Career Research Award - DE 190100160 (JWi). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.