1. Department of Archaeology, University of Cape Town, Rondebosch 7701, Cape Town, Republic of South Africa.
2. Institute of Human Origins, School of Human Evolution and Social Change, Post Office Box 872402, Arizona State University (ASU), Tempe, AZ 85287–4101, USA.
3. UNSW Archaeomagnetic Laboratory and Palaeosciences Laboratory, Integrative Palaeoecology and Anthropology Studies, School of Medical Sciences, University of New South Wales (UNSW), Kensington, New South Wales 2052, Australia.
4. Geomagnetism Laboratory, Department of Earth and Ocean Sciences, University of Liverpool, Liverpool L693BX, UK.
5. GeoQuEST Research Centre, School of Earth and Environmental Sciences, University of Wollongong, Wollongong 2522, Australia.
6. Institut de Recherche sur les Archéomatériaux–Centre de Recherche en Physique Appliquée à l’Archéologie, CNRS-Université de Bordeaux, Maison de l’Archéologie, Esplanade des Antilles, 33607 Pessac, France.
7. Council for Geoscience, Post Office Box 572, Bellville 7535, Republic of South Africa.