R5: Extraterrestrial materials

[R5-02] Micro textures of TCIs in CM carbonaceous chondrites

「発表賞エントリー」

*Akane Iemoto Iemoto¹, Yusuke Seto¹, Akira Miyake² (1. Kobe Univ., Sci., 2. Kyoto Univ., Sci.)

Keywords:CM carbonaceous chondrites, aqueous alteration, TCIs, STEM

We report microtextures of type-II TCIs in five CM chondrites (QUE97990, Murchison, Murray, Cold Bokkeveld, Nogoya), and discuss their formation processes. In the less altered CM chondrites, the TCIs are aggregates of a few µm-sized tochilinite and cronstedtite. In the highly altered CM chondrites, the TCIs showed fluffy and very fine texture, suggesting that TCIs were not formed directly from solid material, but crystallized under mobile environments such as water solution.