1. Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.
2. School of Earth and Environmental Sciences, University of St Andrews, St Andrews KY16 9AL, Scotland, UK.
3. Centre for Exoplanet Science, University of St Andrews, St Andrews KY16 9AL, Scotland, UK.
4. Blue Marble Space Institute of Science, 1001 4th Avenue, Suite 3201, Seattle, WA 98154, USA.
5. Department of Geology, University of Tartu, 50411 Tartu, Estonia.
6. Institute of Geology, Karelian Research Centre, Pushkinskaya 11, 185610 Petrozavodsk, Russia.
7. Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
8. NERC (Natural Environment Research Council) Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham NG12 5GG, England, UK.
9. Department of Earth Science, Rice University, 6100 Main Street, Houston, TX 77005, USA.
10. Department of Geology and Geophysics, E235 Howe-Russell Geoscience Complex, Louisiana State University, Baton Rouge, LA 70803, USA.
11. Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, England, UK.
12. Geological Survey of Norway, 7491 Trondheim, Norway.
13. Institute of Geology, Tallinn University of Technology, 19086 Tallinn, Estonia.