Earliest BIF and Life Produced via Submarine Volcanism in Carbonated Seawater

Abstract

The Isua Banded Iron Formation (BIF) formed just after Late Heavy Bombardment (3.8 Ga) and the first life produced abiotic means appeared in a solution of essential elements on the early Earth. The volcanic layer in the Isua BIF contained no carbon, and the carbon present in the sedimentary layer contained more 12 C than 13 C. Iron-bearing lava was emitted intermittently into the primitive sea through volcanic eruptions. Bubbles were produced then Fe mixed with carbonated water, which may form through multiple chemical pathways. Hydrocarbon (C n H 2n+2 ) was simultaneously produced via collisions between H + from solar wind and early atmospheric CO 2 . Since long-chained molecule of C n H 2n+2 is hydrophobic, they would have floated with membrane of Fe(HCO 3 ) 2 on the surface of the seawater. The carbonated water was neutralized by dissolved ions of Fe +2 and a floating solution of Fe(HCO 3 ) 2 developed in the presence of the BIF. Thus, the floating materials were gathered on the surface of the water. The intermolecular bonds in there floating materials exchanged neighboring atoms as the structure deformed, such that 12 C was preferentially uptaken from carbon derived from the dissolution of CO 2 molecules into the primitive sea at ~3.8 Ga. Given that Fe acts as a deoxidation agent, primitive photosynthesis was achieved in the C n H 2n+2 and Fe(HCO 3 ) 2 via the chemical reaction of Fe(HCO 3 ) 2 in which the hydrophobic C n H 2n+2 molecule was used as a scaffold for replication. Thus, the first life on Earth arose from abiotic processes due to metabolic intermolecular interactions.