Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis

• DOI: 10.1038/s41550-022-01846-1
• Publication Date: 2022-12-12T17:06:28Z
• Authors: Marine Paquet; Frederic Moynier; Tetsuya Yokoyama; Wei Dai; Yan Hu; Yoshinari Abe; Jérôme Aléon; Conel M. O’D. Ale...; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Motoo Ito; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Izumi Nakai; Kazuhide Nagashima; David Nesvorný; Ann N. Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
• Keywords: 550; 440; Zn isotopes; volatile elements; [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]; 500; 01 natural sciences; Article; CI chondrites; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; 13. Climate action; 0103 physical sciences; Ryugu; Cu isotopes; Hayabusa2

Initial analyses showed that asteroid Ryugu’s composition is close to CI (Ivuna-like) carbonaceous chondrites –the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (e.g., Ti, Cr) overlap with other carbonaceous chondrite (CC) groups, so the details of the link between Ryugu and the CI chondrites are not fully clear yet. Here we show that Ryugu and CI chondrites have the same zinc and copper isotopic composition. As the various chondrite groups have very distinct Zn and Cu isotopic signatures, our results point at a common genetic heritage between Ryugu and CI chondrites, ruling out any affinity with other CC groups. Since Ryugu’s pristine samples match the solar elemental composition for many elements, their Zn and Cu isotopic compositions likely represent the best estimates of the solar composition. Earth’s mass-independent Zn isotopic composition is intermediate between Ryugu/CC and non-carbonaceous chondrites, suggesting a contribution of Ryugu-like material to Earth’s budgets of Zn and other moderately volatile elements.