Fig. 4
From: Bio-mediated CN cycling in serpentinites and the origin of life
Conceptual model showing the process that modified the WTO: serpentine (Srp) replaces olivine (Ol) and produces magnetite (Mt) and H (Eq. 1), which participates in the reduction of Cu2+ liberated during the chalcopyrite (Cpy) dissolution (Eq. 2). The microbiome may have participated in fixing Cu0 in the pores. The remaining H2 is consumed by microbiomes as for the NO3– introduced with the serpentinising fluids, leading to the precipitation of the CN– species (Eq. 3). *The stoichiometry of reaction [1] depends on the Mg# of Ol and Srp (Mg# = (MgO % / (MgO % + Fe2O3%)) × 100), and the extent to which aqueous Mg- and Si-bearing species are formed.
