Geophysical Research Letters
Serpentinization of forsteritic olivine results in the inorganic synthesis of molecular hydrogen (H(2)) in ultramafic hydrothermal systems (e. g., mid-ocean ridge and forearc environments). Inorganic carbon in those hydrothermal systems may react with H(2) to produce methane (CH(4)) and other hydrocarbons or react with dissolved metal ions to form carbonate minerals. Here, we report serpentinization experiments at 200 degrees C and 300 bar demonstrating Fe(2+) being incorporated into carbonates more rapidly than Fe(2+) oxidation (and concomitant H(2) formation) leading to diminished yields of H(2) and H(2)-dependent CH(4). In addition, carbonate formation is temporally fast in carbonate oversaturated fluids. Our results demonstrate that carbonate chemistry ultimately modulates the abiotic synthesis of both H(2) and CH(4) in hydrothermal ultramafic systems and that ultramafic systems present great potential for CO(2)-mineral sequestration.
Copyright (2010) American Geophysical Union. To view the published open abstract, go to http://dx.doi.org and enter the DOI, 10.1029/2010GL043769.
Jones, L. C., R. Rosenbauer, J. I. Goldsmith, and C. Oze (2010), Carbonate control of H(2) and Ch(4) production in serpentinization systems at elevated P-Ts, Geophys. Res. Lett., 37, L14306.