1. Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, U.K.
2. Institute of Geological Sciences, University of Bern, Baltzerstrasse 3, Bern CH-3012, Switzerland
3. Department of Geology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
4. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
5. Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
6. Institute of Chemical Engineering, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria