The Earth atmosphere-like bulk nitrogen isotope composition obtained by stepwise combustion analyses of Ryugu return samples ...

• Main Authors: Hashizume, Ko, Ishida, Akizumi, Chiba, Ayano, Okazaki, Ryuji, Yogata, Kasumi, Yada, Toru, Kitajima, Fumio, Yurimoto, Hisayoshi, Nakamura, Tomoki, Noguchi, Takaaki, Yabuta, Hikaru, Naraoka, Hiroshi, Takano, Yoshinori, Sakamoto, Kanako, Tachibana, Shogo, Nishimura, Masahiro, Nakato, Aiko, Miyazaki, Akiko, Abe, Masanao, Okada, Tatsuaki, Busemann, Henner, et al.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2024
• Subjects: Antarctic; Ryugu; Antarc*
• Online Access: https://dx.doi.org/10.3929/ethz-b-000673030; http://hdl.handle.net/20.500.11850/673030

The nitrogen isotope compositions of two samples returned from the asteroid Ryugu were determined using a stepwise combustion method, along with Ivuna (CI) and Y-980115, a CI-like Antarctic meteorite, as references. The two Ryugu samples A0105-07 and C0106-07 showed bulk delta 15N values of +1.7 +/- 0.5 parts per thousand and +0.2 +/- 0.6 parts per thousand, respectively, significantly lower than Ivuna with +36.4 +/- 0.4 parts per thousand, but close to Y-980115 with +4.0 +/- 0.3 parts per thousand. The Ryugu samples are further characterized by C/N and 36Ar/N ratios up to 3.4x and 4.9x the value of Ivuna, respectively. Among all Ryugu samples and CI chondrites, a positive correlation was observed between nitrogen concentrations and delta 15N values, with samples with lower nitrogen concentrations exhibiting lower delta 15N. This trend is explained by a two-component mixing model. One component is present at a constant abundance among all CI-related samples, with a delta 15N value around 0 parts per thousand ... : Meteoritics & Planetary Science, 59 (8) ...