R4: Mineral sciences of the Earth surface

[R4-07] Saponite-ammonium interaction:Reconstruction of ammonium concentration of early ocean on Ceres

*Hiroto Tokumon¹, Keisuke Fukushi², Yasuhito Sekine³, Kosuke Inoue¹ (1. Kanazawa Univ. Sci., 2. Institute of Nature and Environmental Technology, Kanazawa Univ, 3. Tokyo Institute of Technology)

Keywords:Ceres, Saponite, Exchange coeffcient

NASA's Dawn survey suggests that Ceres has ammonium-type saponite, which contains ammonium ions in its interlayer and it is highly likely that the ammonium-type saponite records the concentration of ammonium in the ocean that existed on Ceres in the past.
In this study, we will quantitatively measure the Na⁺-NH₄⁺ selection coefficient of saponite, which is essential for the Ceres water quality reconstruction, and try to reconstruct the detailed ammonium concentration in the early Ceres ocean by correlating the obtained results with the IR results of NASA's Ceres exploration.