Experimental hydrogen production in hydrothermal and fault systems: Significance for habitability of subseafloor H2 chemoautotroph microbial ecosystems

Abstract

Hydrogen generated in hydrothermal and fault systems has recently received considerable attention as a potential energy source for hydrogen-based microbial activity such as methanogenesis. Laboratory experiments that have reproduced conditions for the serpentinization of ultramafic rocks such as peridotite and komatiite have clarified the chemical and petrological processes of H2 production. In a frictional experimental study, we recently showed that abundant H2 can also be generated in a simulated fault system. This result suggests that microbial ecosystems might exist in subseafloor fault systems. Here we review the experimental constraints on hydrogen production in hydrothermal and fault systems.