Kliti Grice^1,2, Calum Fox³, Jessica Hope Whiteside⁴, Paul E Olsen⁵, Xingqian Cui⁶ and Roger E Summons⁶, (1)University of Bristol, Bristol, BS8, United Kingdom, (2)Curtin University, WA Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Perth, WA, Australia, (3)Curtin University, Department of Chemistry, Perth, WA, Australia, (4)University of Southampton, Southampton, SO14, United Kingdom, (5)Columbia University of New York, Earth and Environmental Science, NY, NY, United States, (6)Massachusetts Institute of Technology, Earth, Atmospheric and Planetary Sciences, Cambridge, MA, United States