1. School of Ocean and Earth Science, University of Southampton, Waterfront Campus, National Oceanography Centre Southampton, European Way, Southampton SO14 3ZH, UK
2. Ores and Mineralization Group, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK
3. School of Applied Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ, UK
4. c/o Department of Scottish History & Archaeology, National Museums Scotland, Chambers Street, Edinburgh EH1 1JF, UK