S2: Water Rock Interaction (Special Session)

[S2-03] Relationship between the physical properties and hydration of the oceanic lower crust/ Moho TZ: results from onboard measurements of ICDP Oman Drilling Project (ChikyuOman)

*Natsue Abe Abe¹, Keishi Okazaki², Ikuo Katayama³, Kohei Hatakeyama³, Yuya Akamatsu³, Science Party ICDP OmanDP (1. Mantle Drilling Promotion Office (MDP), MarE3, JAMSTEC, 2. KCC, X-star, JAMSTEC, 3. Hiroshima University)

Keywords:ICDP Oman Drilling Project, D/V Chikyu, Ophiolite, Oceanic Crust, Moho TZ

We report results on the physical property measurements drilled in the crust-mantle boundary from gabbroic sequence to harzburgite sequence through dunite sequences at Oman Ophiolite. Dunite shows lower density, P-wave velocity and electrical resistivity, and higher porosity than those of harzburgite. Since the most lithologies originally contain wide modal proportion of olivine that currently serpentinized and contain magnetite grains, our physical property data show clear correlation with magnetic susceptibility and bulk Fe content.