1. GNS Science, Private Bag 1930, Dunedin, New Zealand
2. Department of Geology, University of Otago, PO Box 56, Dunedin, New Zealand
3. Science and Engineering, University of Waikato, Hamilton, New Zealand
4. Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA
5. School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
6. School of Biological, Earth and Environmental Science, University College Cork, Distillery Fields, North Mall, Cork, Ireland