Mineral self-organization in extreme geochemical environmentsImplications for prebiotic chemistry and life detection

Résumé

The overarching goal of this thesis was to investigate the role of mineral self-organization and abiotic mineral precipitation in early Earth geochemistry, prebiotic chemistry and life detection, by focusing on two case studies: a) the precipitation and nanoscale characterization of iron-silica selforganized, filamentous membranes, grown from both synthetic and natural solutions, and b) the geochemistry and mineral precipitation at the polyextreme hydrothermal system of Dallol, the physicochemical conditions of which impose a limit to the habitable space of life. In a nutshell, the study of inorganic mineral precipitation and mineral self-organization in extreme geochemical environments may provide insight on the mineral processes that occurred on early Earth and most probably paved the geochemical pathway to life. Given that inorganic mineral precipitation and mineral self-organization commonly produce morphologically and chemically similar structures to biologic ones, their study has direct implications on fossil life detection in the rock record of Earth and Earth-like planets.