JpGU-AGU Joint Meeting 2017

講演情報

[JJ]Eveningポスター発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS10] [JJ] 太陽系における惑星物質の形成と進化

2017年5月22日(月) 17:15 〜 18:30 ポスター会場 (国際展示場 7ホール)

[PPS10-P18] Hydrogen Reservoirs in Mars as Revealed by SNC Meteorites

*臼井 寛裕1 (1.東京工業大学地球生命研究所)

キーワード:水素同位体、火星隕石

The isotopic signatures of three hydrogen reservoirs are now identified based on analyses of Martian meteorites, telescopic observations, and Curiosity measurements: primordial water, surface water, and subsurface water (Usui, in press). The primordial water is retained in the mantle and has a D/H ratio similar to those seen in Martian building blocks (Usui et al. 2012). The surface water has been isotopically exchanged with the atmospheric water of which D/H ratio has increased through the planet’s history to reach the present-day mean value of ~5,000‰ (Kurokawa et al. 2014). The subsurface water reservoir has intermediate δD values (~1,000-2,000‰), which are distinct from the low-δD primordial and the high-δD surface water reservoirs. We proposed that the intermediate-δD reservoir represents either hydrated crust and/or ground ice interbedded within sediments (Usui et al. 2015). The hydrated crustal materials and/or ground ice could have acquired its intermediate-δD composition from the ancient surface water reservoir (Usui et al. 2017).

References:
Kurokawa, H. et al. (2014). Evolution of water reservoirs on Mars: Constraints from hydrogen isotopes in martian meteorites. Earth Planet. Sci. Lett. 394, 179-185.
Usui et al. (2012) Origin of water and mantle-crust interactions on Mars inferred from hydrogen isotopes and volatile element abundances of olivine-hosted melt inclusions of primitive shergottites. Earth Planet. Sci. Lett. 357-358, 119-129.
Usui et al. (2015) Meteoritic evidence for a previously unrecognized hydrogen reservoir on Mars. Earth Planet. Sci. Lett. 410, 140-151.
Usui et al. (2017) Hydrogen isotopic constraints on the evolution of surface and subsurface water on Mars. The 48th Lunar Planetary Science Conference, Abstract #1278.
Usui et al. (in press) Hydrogen reservoirs in Mars as revealed by SNC meteorites. Volatiles In The Martian Crust (eds. Filiberoto J. and Schwenzer S. P.), Elsevier B.V.