DOI 10.1371/journal.pone.0270104 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.
| File | Pages | Size | Access | |
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Publisher's official version | 21 | 1 Mo | ||
S1 Checklist. PLOS ONE inclusivity in global research questionnaire. | 4 | 90 Ko | ||
S1 Fig. Photographs of cascade hand and drill core samples. | 1 | 764 Ko | ||
S2 Fig. Field photographs, hand samples and thin section photomicrographs of rim pool samples. | 1 | 2 Mo | ||
S3 Fig. Photographs of terrace breccia hand samples. | 1 | 3 Mo | ||
S4 Fig. Photographs, hand sample scans and thin section photographs of barrage tufas. | 1 | 2 Mo | ||
S5 Fig. Photographs of sampled domes. | 1 | 2 Mo | ||
S7 Fig. High resolution images of cascade core samples (18–13, 18–14, 18–15, 18–16, 18–17) overlain by LA-ICP-MS 238U (left) and 232Th (right) element distribution maps. | 1 | 2 Mo | ||
S8 Fig. High resolution images of samples with unreliable and imprecise age solutions (S3 Table) with the exception of sample 18–10.2 (bottom of sample) which has an age of 3.0 ± 0.9 ka. | 1 | 2 Mo | ||
S1 Table. Tufa sample inventory. Samples labelled and listed in order of collection. | 1 | 52 Ko | ||
S2 Table. U and Th isotope ratios measured in tufa samples with reliable and precise ages. | 2 | 56 Ko | ||
S3 Table. U and Th isotope ratios measured in tufa samples which have unreliable or imprecise age solutions. | 1 | 54 Ko |
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