1. a School of Geography and Earth Sciences , McMaster University , Hamilton , Ontario , Canada
2. b Lamont-Doherty Earth Observatory , Columbia University New York , New York, USA: Geo ForschungsZentrum Potsdam, Potsdam , Germany
3. c Division of Earth and Ecosystems Sciences (DEES) , Desert Research Institute , Las Vegas , Nevada , USA
4. d Woods Hole Oceanographic Institution , Woods Hole , Massachusetts , USA
5. e Department of Geosciences , Princeton University , Princeton , New Jersey , USA
6. f Department of Geology , University of Toronto , Toronto , Ontario , Canada