R5: Extraterrestrial materials

[R5P-01] TEM observations of a cosmic symplectite in the Acfer 094 meteorite

*Megumi Matsumoto¹, Akira Tsuchiyama^2,3, Akira Miyake⁴, Naotaka Tomioka⁵, Motoo Ito⁵, Yu Kodama⁶, Junya Matsuno⁴, Masahiro Yasutake², Aiko Nakato⁷, Kentaro Uesugi⁸, Akihisa Takeuchi⁸, Tsukasa Nakano⁹, Epifanio Vaccaro¹⁰ (1. Tohoku Univ., 2. Ritsumeikan Univ., 3. GIG/CAS, 4. Kyoto Univ., 5. JAMSTEC, 6. Marine Works Japan, 7. JAXA/ISAS, 8. JASRI/SPring-8, 9. GSJ/AIST, 10. NHM in London)

Keywords:Acfer 094 meteorite, Cosmic symplectite, metal-sulfate interaction, TEM

We performed TEM observations of a cosmic symplectite (COS) in Acfer 094 meteorite, and found that the COS contains Na-sulfate as an inclusion. The microstructure inside the COS grain, nanometer-scaled symplectitically intergrowth of magnetite and Fe-Ni sulfides, is thought to have been formed through interaction between Na-sulfate and pre-existing Fe-Ni metal under high temperature condition before the accretion to the Acfer 094 parent body.