1. Department of Archaeology, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia.
2. Corresponding author.
3. Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia.
4. Applied Archaeology, PO Box 4025, Albany, WA 6330, Australia.
5. Anthropology and Archaeology Department, Western Australian Museum, Locked Bag 49, Welshpool DC, WA 6986, Australia.