Tullis C Onstott¹, Thomas L Kieft², Devan Nisson³, Oliver Warr⁴, Barbara Sherwood Lollar⁵, Barry M Freifeld⁶, Chui Yim Maggie Lau¹, Hiroshi Ogasawara⁷, Susan Jane Webb⁸, Zachary K Garvin¹, Rachel Lee Harris¹, Errol Duncan Cason⁹, Julio Castillo Hernandez¹⁰, Jan-G Vermeulen¹⁰, Esta van Heerden¹¹, Bennie Leibenberg¹², Wesley Harrison¹³, Raymond J Durrheim¹³, Musa Siphiwe Manzi¹⁴ and Clifford C Walters¹⁵, (1)Princeton University, Department of Geosciences, Princeton, NJ, United States, (2)New Mexico Institute of Technology, Department of Biology, Socorro, NM, United States, (3)Princeton University, Princeton, NJ, United States, (4)University of Toronto, Department of Earth Sciences, Toronto, ON, Canada, (5)University of Toronto, Earth Sciences, Toronto, ON, Canada, (6)Lawrence Berkeley National Laboratory, Berkeley, CA, United States, (7)Ritsumeikan University, Kusathu, Japan, (8)Univ Witwatersrand, Johannesburg, South Africa, (9)University of the Free State, Department of Microbial, Biochemical and Food Technology, Bloemfontein, South Africa, (10)University of the Freestate, Department of Microbial, Biochemical and Food Technology, Bloemfontein, Free State, South Africa, (11)North-West University, Mahikeng, South Africa, (12)Leibenberg, Orkney, South Africa, (13)University of the Witwatersrand, School of Geosciences, Johannesburg, South Africa, (14)University of Witwatersrand, School of Geosciences, Wits, South Africa, (15)ExxonMobil Research and Engineering Company, Annandale, NJ, United States