1. Human Origins and Palaeoenvironmental Research Group (HOPE), Department of Anthropology & Geography, Oxford Brookes University, Oxford OX3 0BP, UK
2. Leverhulme Centre for Human Evolutionary Studies, University of Cambridge, Henry Wellcome Building, Fitzwilliam Street, Cambridge CB2 1QH, UK
3. Computational Geomechanics, Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK
4. Department of Archaeology, University of Cambridge, Cambridge CB2 3QG, UK,
5. McDonald Institute for Archaeological Research, University of Cambridge, Downing Street, Cambridge CB2 3ER, UK