Presentation Information
[R3-P-06]Temperature and coexisting-phase dependence of water solubility in wadsleyite
*Hanae Kaya1, Toru Inoue1, Yushi Hamada2, Takaaki Kawazoe1, Goru Takaichi1 (1. Hiroshima Univ. Adv. Sci. & Eng., 2. Hiroshima Univ. Sci.)
Keywords:
wadsleyite,maximum water content,hydrous melt,hydrous phase,mantle transition zone
Wadsleyite (Wd) is a major constituent mineral of the mantle transition zone (corresponding to 410–660 km depth). Although Wd is nominally anhydrous mineral (NAM), it has been shown that water can be present in the crystal structure at several wt% levels (e.g. Inoue et al., 1995; Kudoh et al., 1996). The water contents of Wd are observed to have temperature dependence (e.g. Ohtani et al., 2001; Litasov and Ohtani, 2003). Though the water contents under high-temperature conditions are becoming approximately constrained, the water contents under low-temperature conditions have still discrepancy between the previous studies (e.g., Demouchy et al., 2005; Ishii and Ohtani, 2021). The average mantle temperature is around 1500℃ (Ito and Katsura, 1989), but the temperature of subducting slabs is estimated to be 500–900℃ (Kirby et al., 1996). Thus, the constraint on water contents under low-temperature conditions is also important for understanding deep Earth dynamics. Therefore, we conducted high-pressure experiments to investigate the maximum water solubility in Wd, especially under low temperature conditions.
