2022 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)

Presentation information

Oral presentation

S2: Water Rock Interaction (Special Session)

Sat. Sep 17, 2022 10:00 AM - 12:30 PM B351 (Adv. Edu. Res. Bldg. E-3F)

Chairperson: Tsuchiya Noriyoshi(Tohoku Univ.)

10:45 AM - 11:00 AM

[S2-04] Effect of silica on iron partitioning during serpentinization

[Presentation award entry]

*Shuhei Tanaka1, Atsushi Okamoto1, Kazuki Yoshida1, Yasuhiro Niwa2,3, Masao Kimura2,3, Masaoki Uno1, Masakazu Fujii4,5 (1. Tohoku Univ. Env., 2. IMSS, 3. KEK, 4. NIPR, 5. The Graduate Univ. for Advanced Studies)

Keywords:Serpentinization, Silica, Iron partitioning

Serpentinization of mantle peridotite, containing olivine (Ol) and orthopyroxene (Opx) involves oxidation of Fe and H2 production. However, the effect of high silica activity by Opx reaction on iron partitioning and H2 production is unclear. In this study, we conducted batch type experiments of Ol-H2O and Ol-Opx-H2O systems at 200-400℃. In Ol-Opx-H2O system, Opx reacted selectively above 300℃, and little magnetite was produced. However, H2 production rate was comparable to that of the Ol-H2O system by Fe3+ in serpentine, indicating silica changed the mechanism of H2 generation.