S2: Water Rock Interaction (Special Session)

3:15 PM - 3:30 PM JST(6:15 AM - 6:30 AM UTC)

[S2-11] Where seawater meets the mantle

*Tatsuhiko KAWAMOTO¹ (1. Shizuoka Univ. Sci.)

Keywords:

fluid inclusion,saline fluids,homogenization temperature,oxygen isotope geothermometer,hydrogen isotope

I have been studying aqueous fluid in the lower mantle. I have observed fluid inclusions of saline fluids in mantle peridotite, carbonate minerals in serpentinite, and listvenite. The salinity is close to or slightly higher than that of the present seawater. Since Cl would be more partitioned into aqueous fluids rather than minerals and the salt concentration would increase if water vapor is removed from the system by boiling, such saline fluids can be of seawater origin. So, we now WANT to know where seawater at the surface meets the mantle.