¹Sota Arakawa,²Daiki Yamamoto,³Takayuki Ushikubo,⁴Hiroaki Kaneko,⁵Hidekazu Tanaka,¹Shigenobu Hirose,⁴Taishi Nakamoto
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2023.115690]
¹Yokohama Institute for Earth Sciences, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, 236-0001, Japan
²Department of Earth and Planetary Sciences, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
³Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology, 200 Monobe-otsu, Nankoku, Kochi, 783-8502, Japan
⁴Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo, 152-8550, Japan
⁵Astronomical Institute, Graduate School of Science, Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai, 980-8578, Japan
Copyright ELsevier

Oxygen isotope compositions of chondrules reflect the environment of chondrule formation and its spatial and temporal variations. Here, we present a theoretical model of oxygen isotope exchange reaction between molten silicate spherules and ambient water vapor with finite relative velocity. We found a new phenomenon, that is, mass-dependent fractionation caused by isotope exchange with ambient vapor moving with nonzero relative velocity. We also discussed the plausible condition for chondrule formation from the point of view of oxygen isotope compositions. Our findings indicate that the relative velocity between chondrules and ambient vapor would be lower than several 100ms−1 when chondrules crystallized.