1. Department of Earth Sciences Memorial University of Newfoundland St. John's NL Canada
2. Université de Paris Institut de Physique du Globe de Paris UMR CNRS Paris France
3. Laboratoire de Géologie – CNRS UMR École Normale Supérieure PSL University Paris France
4. Department of Earth Science/K. G. Jebsen Centre for Deep Sea Research University of Bergen Bergen Norway