^1,2Zhi Li,^1,3Ying-Kui Xu,^4,5Shui-Jiong Wang,⁴Si-Zhang Sheng,^1,3Shi-Jie Li,^1,3Xiong-Yao Li,^1,3Jian-Zhong Liu,⁶Dan Zhu
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14369]
¹Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China
²College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
³CAS Center for Excellence in Comparative Planetology, Hefei, China
⁴State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing, China
⁵Frontiers Science Center for Deep-Time Digital Earth, China University of Geosciences (Beijing), Beijing, China
⁶State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China
Published by arrangement with John Wiley & Sons

High-energy impact events prevalent during planetary accretion in the solar system’s evolution significantly shaped planetary bodies, though the effects of shock metamorphism on nickel (Ni) isotope fractionation remain unclear. To investigate the effect of the shock process on Ni isotopes, we selected three shocked ordinary chondrites (OCs) and obtained three sample pairs, each consisting of a melted region and its corresponding unmelted region. We also prepared two whole rock samples and four pairs of magnetic and coupled nonmagnetic samples. The shock melt pockets (SMPs) from three shocked OCs (Chelyabinsk LL5, Viñales L6, Tassédet 004 H5) show δ⁶⁰Ni values of 0.15 ± 0.05‰, 0.14 ± 0.02‰, and 0.20 ± 0.04‰, while adjacent unmelted parts show δ⁶⁰Ni values of 0.21 ± 0.03‰, 0.19 ± 0.01‰, and 0.19 ± 0.03‰. These data are slightly higher than the BSE value (0.11 ± 0.01‰) but generally overlap with the Ni isotopic variation of OCs (0.15–0.51‰) reported in previous studies. The SMPs do not show discernible isotopic variations relative to coupled unmelted parts, suggesting that shock-induced evaporation could not cause Ni isotope fractionation. The value of bulk OCs is calculated by compiling data from previous and this study, yielding a value of ‰0.21−0.11+0.28‰. Moreover, no consistent Ni isotopic variations from four pairs of magnetic and nonmagnetic counterparts are observed. Several possible processes resulting in Ni isotopic variations are discussed. A slight negative correlation between S content and Ni isotopic composition, along with a positive correlation between Ni elemental and isotopic composition in shocked OCs, suggests that the Ni isotopic characteristics may be predominantly influenced by the relative proportions of metal and sulfide phases.