The Fe-Rich Clay Microsystems in Basalt-Komatiite Lavas: Importance of Fe-Smectites for Pre-Biotic Molecule Catalysis During the Hadean Eon

Abstract

During the Hadean to early Archean period (4.5-3.5 Ga), the surface of the Earth's crust was predominantly composed of basalt and komatiite lavas. The conditions imposed by the chemical composition of these rocks favoured the crystallization of Fe-Mg clays rather than that of Al-rich ones (montmorillonite). Fe-Mg clays were formed inside chemical microsystems through sea weathering or hydrothermal alteration, and for the most part, through post-magmatic processes. Indeed, at the end of the cooling stage, Fe-Mg clays precipitated directly from the residual liquid which concentrated in the voids remaining in the crystal framework of the mafic-ultramafic lavas. Nontronite-celadonite and chlorite-saponite covered all the solid surfaces (crystals, glass) and are associated with tiny pyroxene and apatite crystals forming the so-called "mesostasis". The mesostasis was scattered in the lava body as micro-settings tens of micrometres wide. Thus, every square metre of basalt or komatiite rocks was punctuated by myriads of clay-rich patches, each of them potentially behaving as a single chemical reactor which could concentrate the organics diluted in the ocean water. Considering the high catalytic potentiality of clays, and particularly those of the Fe-rich ones (electron exchangers), it is probable that large parts of the surface of the young Earth participated in the synthesis of prebiotic molecules during the Hadean to early Archean period through innumerable clay-rich micro-settings in the massive parts and the altered surfaces of komatiite and basaltic lavas. This leads us to suggest that Fe,Mg-clays should be preferred to Al-rich ones (montmorillonite) to conduct experiments for the synthesis and the polymerisation of prebiotic molecules.

Adsorption of nucleotides onto ferromagnesian phyllosilicates: Significance for the origin of life

“…In summary, nontronites may be regarded as strong candidates for the concentration of nucleotides in the origin of life context because on the one hand, they are abundant hydrothermal alteration products developing very high specific surface area (Meunier et al, 2010); and on the other hand, they exhibit the most diverse and favorable behaviors for adsorption of nucleotides among all the minerals we tested. Nontronites can concentrate nucleotides up to 1 M under neutral to low pH and are becoming even more efficient in adsorbing those molecules at very high equilibrium concentration.…”

“…chlorite. Geochemically relevant minerals would then include Fe-Mg-rich swelling and non-swelling clays and serpentines, as proposed by Meunier et al (2010). Therefore, the present study focuses on the abovementioned Fe-Mg phyllosilicates and assesses their potential as nucleotide adsorbents.…”

Formation of Replicating Saponite from a Gel in the Presence of Oxalate: Implications for the Formation of Clay Minerals in Carbonaceous Chondrites and the Origin of Life

“…The potential role of clay minerals in these processes was first recognized by Bernal (1949), who suggested that their surfaces are the likely location where organic molecules that occurred in warm tidal ponds or in the ocean (primordial ''soup'') could concentrate and polymerize more complex organic compounds such as amino acids. These ideas were further developed by Cairns-Smith (1965), Cairns-Smith and Hartman (1986), Balogh and Laszlo (1993), Ertem and Ferris (1996), Hanczyc et al (2003), and Meunier et al (2010). Hartman et al (1993) proposed, moreover, that the complex interaction between polar organic compounds and claymineral formation in carbonaceous chondrites, a class of meteorite, would be indicative of what may have occurred on early Earth.…”

Missions to Mars: Characterisation of Mars analogue rocks for the International Space Analogue Rockstore (ISAR)

“…The different alteration stages resulted in the formation of phyllosilicates, such as Fe-Mg smectites (saponite, nontronite) in the first period, and Al-rich smectites under the later, more acidic conditions. Although phyllosilicates can be formed by deuteric processes, in particular during fractionation within the magmatic chamber (Meunier al., 2010;, aqueous alteration of rocks is the most commonly proposed formation process to explain the presence of phyllosilicate occurrences on Mars (e.g. Poulet et al, 2005;Bibring et al, 2006;Ehlmann et al, 2009;Viles et al, 2010).…”

“…This laboratory-synthesised nontronite was chosen as an analogue of phyllosilicates formed by basalt alteration in neutral conditions on Mars (Bibring et al, 2006;Meunier et al, 2010).…”