[1] British Museum, Dept Prehistory & Europe, London N1 5QJ, England
[2] UCL, Inst Archaeol, London WC1H 0PY, England
[3] Nat Hist Museum, Dept Palaeontol, London SW7 5BD, England
[4] Queen Mary Univ London, Dept Geog, London E1 4NS, England
[5] Nat Hist Museum, Dept Mineral, London SW7 5BD, England
[6] Leiden Univ, Dept Archaeol, NL-2300 RA Leiden, Netherlands
[7] Univ Birmingham, Sch Earth Sci, Birmingham B15 2TT, W Midlands, England
[8] Royal Bot Gardens, Jodrell Lab, Richmond TW9 3AB, Surrey, England
[9] Univ Sydney, Sch Geosci, Sydney, NSW 2006, Australia
[10] Norfolk Museums & Archaeol Serv, Norwich NR1 3JQ, Norfolk, England
[11] Univ Lancaster, Ctr Environm Magnetism & Palaeomagnetism, Lancaster Environm Ctr, Lancaster LA1 4YQ, England
[12] Univ Cambridge, Dept Zool, Cambridge CB2 3EJ, England