*Katy Jane Chamberlain¹、Jenni Barclay²、Katie Preece³、Richard J Brown⁴、Iona McIntosh⁵、E IMF⁶ (1.ESRC, School of Environmental Sciences, University of Derby, Derby, DE22 1GB, UKUniversity of Derby、2.School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK、3.Department of Geography, College of Science, Swansea University, Swansea, SA2 8PP, UK.、4.Department of Earth Sciences, Durham University, Durham, DH1 3LE, UK、5.Institute for Marine Geodynamics, Japan Agency for Marine Earth Science and Technology, Yokosuka 237-0061, Japan、6.Edinburgh Ion Microprobe Facility, University of Edinburgh, Edinburgh, EH9 3FE, UK)