Geochemical bio-signatures in Martian analogue basaltic environments using laboratory experiments and thermochemical modelling

The identification of geochemical bio-signatures is important for assessing whether life existed on early Mars. In this paper, experimental microbiology and thermochemical modelling were combined to identify potential inorganic detection An analogue mixed microbial community from an terrestrial fluvio-lacustrine environment similar ancient lacustrine system at Gale Crater was used study dissolution a basalt regolith simulant the formation over short time frame (1°month) 14°C, 2 bar. Microbial growth influenced element (Mg, Fe, Mn, Ca K) morphologies Fe-Si amorphous layers mineral surfaces. Thermochemical models performed bar; results compared with data predict that would occur geological timescales. pH varied simulate abiotic biotic conditions. Model suggest that, water rock ratios 100 38, less complex secondary assemblage forms during weathering. Carbonates, quartz, pyrite hydroxyapatite form under conditions, whereas in magnetite phyllosilicates also precipitate. These could be distinguish between weathering processes, aiding interpretation Mars exploration missions.