R3: High-pressure science and deep Earth’s material

[R3P-07] Water contents of magma as functions of
pressure and temperature at the uppermost lower mantle

*OKUMURA KOTA¹, Toru INOUE¹, Sho KAKIZAWA¹, Masamichi NODA¹, Takaaki KAWAZOE¹, Tomoko SATO¹, Toru SHINMEI², Tetsuo IRIFUNE² (1. Hiroshima Univ. Adv. Sci. Eng., 2. Ehime Uni. GRC)

Keywords:Water content in magma, Phase diagram, Uppermost lower mantle

We clarified the water content of magma generated at the uppermost lower mantle condition. The experimental conditions were at 25 GPa and 1200-1700℃. When we adopted the mantle temperature at 1650℃, the water content was estimated to be about 23 wt% from our determined liquidus line. Considering the density of magma as a function of water content, it is concluded that the hydrous magma generated at the uppermost lower mantle condition should be gravitationally unstable.