Four‐dimensional‐STEM analysis of the phyllosilicate‐rich matrix of Ryugu samples

Mouloud, B.‐e. et al. (2024) Four‐dimensional‐STEM analysis of the phyllosilicate‐rich matrix of Ryugu samples. Meteoritics and Planetary Science, (doi: 10.1111/maps.14124) (Early Online Publication)

Abstract

Ryugu asteroid grains brought back to the Earth by the Hayabusa2 space mission are pristine samples containing hydrated minerals and organic compounds. Here, we investigate the mineralogy of their phyllosilicate-rich matrix with four-dimensional scanning transmission electron microscopy (4D-STEM). We have identified and mapped the mineral phases at the nanometer scale (serpentine, smectite, pyrrhotite), observed the presence of Ni-bearing pyrrhotite, and identified the serpentine polymorph as lizardite, in agreement with the reported aqueous alteration history of Ryugu. Furthermore, we have mapped the d-spacings of smectite and observed a broad distribution of values, ranging from 1 to 2 nm, with an average d-spacing of 1.24 nm, indicating significant heterogeneity within the sample. Such d-spacing variability could be the result of either the presence of organic matter trapped in the interlayers or the influence of various geochemical conditions at the submicrometer scale, suggestive of a range of organic compounds and/or changes in smectite crystal chemistry.

• Item Type: Articles
• Additional Information: The Chevreul Institute is thanked for its help in the development of this work through the CHEMACT project supported by the “Ministère de l’Enseignement Supérieur de la Recherche et de l’Innovation,” the region “Hauts-de-France” and the “Métropole Européenne de Lille.
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Daly, Dr Luke and Lee, Professor Martin
• Authors: Mouloud, B.‐e., Jacob, D., de la Peña, F., Marinova, M., Le Guillou, C., Viennet, J.‐C., Laforet, S., Leroux, H., Teurtrie, A., Noguchi, T., Matsumoto, T., Miyake, A., Igami, Y., Haruta, M., Saito, H., Hata, S., Seto, Y., Miyahara, M., Tomioka, N., Ishii, H. A., Bradley, J. P., Ohtaki, K. K., Dobrica, E., Langenhorst, F., Harries, D., Beck, P., Phan, T. H. V., Rebois, R., Abreu, N. M., Gray, J., Zega, T., Zanetta, P.‐M., Thompson, M. S., Stroud, R., Burgess, K., Cymes, B. A., Bridges, J. C., Hicks, L., Lee, M. R., Daly, L., Bland, P. A., Zolensky, M. E., Frank, D. R., Martinez, J., Tsuchiyama, A., Yasutake, M., Matsuno, J., Okumura, S., Mitsukawa, I., Uesugi, K., Uesugi, M., Takeuchi, A., Sun, M., Enju, S., Takigawa, A., Michikami, T., Nakamura, T., Matsumoto, M., Nakauchi, Y., Abe, M., Nakazawa, S., Okada, T., Saiki, T., Tanaka, S., Terui, F., Yoshikawa, M., Miyazaki, A., Nakato, A., Nishimura, M., Usui, T., Yada, T., Yurimoto, H., Nagashima, K., Kawasaki, N., Sakamotoa, N., Okazaki, R., Yabuta, H., Naraoka, H., Sakamoto, K., Tachibana, S., Watanabe, S.‐i., and Tsuda, Y.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Meteoritics and Planetary Science
• Publisher: Wiley
• ISSN: 1086-9379
• ISSN (Online): 1945-5100
• Published Online: 05 January 2024
• Copyright Holders: Copyright: © 2024 The Authors
• First Published: First published in Meteoritics and Planetary Science 2024
• Publisher Policy: Reproduced under a Creative Commons licence