A small S-MIF signal in Martian regolith pyrite: Implications for the atmosphere

Abstract

2002), through at least two great oxidation events (e.g., Campbell and Allen, 2008;Farquhar et al., 2014), probably caused by photosynthesising microorganisms (e.g., Campbell and Squire, 2010). The first great oxidation event occurred at about 2.4-2.3 Ga, and is best evidenced by a distinct change in the S isotope signature of sedimentary sulfide and sulfate minerals (Farquhar et al., 2014). Prior to this first great oxidation event these minerals record distinct signatures of massindependently fractionated sulfur isotopes, whereas afterwards this signature disappears completely (Farquhar et al., 2014).

Functional basis of primary succession: Traits of the pioneer microbes

“…As primary succession requires microbes to establish a new community under ‘bare minimum’ conditions, their metabolic processes and survival strategies may give some insights into how life evolved on Earth (abiogenesis) and potentially other planets (exobiology). Indeed, the genesis of life on, or transport to, another planet represents primary succession in an extreme context (Michalski et al, 2018 ; Tomkins et al, 2020 ). Our understanding of this process on Earth is likely to inform our conceptualisation of the origin of life elsewhere.…”