R5: Extraterrestrial materials

[R5-04] Dolomite in the Ivuna meteorite (CI) and search for its fluid inclusions

*Akira Tsuchiyama¹, Momoko Hashino², Akira Kitayama², Akira Miyake² (1. Ritsumeikan Univ./GIG, 2. Kyoto Univ., Sci.)

Keywords:Ivuna meteorite, dolomite, fluid inclusion, X-ray nanotomography, cryo TEM

We tried to find fluid inclusions in dolomite of the Ivuna meteorite, which was received strong aqueous alteration. Based on the features of dolomite located in different lithologies with different degrees of aqueous metamorphism, dolomite precipitated in the early stage of the metamorphism, received reaction to form sulfate (gypsum) and finally disappeared. X-ray nanotomography and cryo TEM observation showed that dolomite have a lot of inclusions with facets but they are vacant. The above results suggest that fluid was escaped form fluid inclusions by the reaction