Japan Geoscience Union Meeting 2021

Presentation information

[J] Oral

P (Space and Planetary Sciences ) » P-PS Planetary Sciences

[P-PS07] Formation and evolution of planetary materials in the Solar System

Sat. Jun 5, 2021 10:45 AM - 12:15 PM Ch.04 (Zoom Room 04)

convener:Megumi Matsumoto(Graduate School of Science, Tohoku University), Shin Ozawa(Department of Earth Science, Graduate School of Science, Tohoku University), Yuki Hibiya(Submarine Resources Research Center, Japan Agency for Marine-Earth Science and Technology), Noriyuki Kawasaki(Department of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University), Chairperson:Shin Ozawa(Department of Earth Science, Graduate School of Science, Tohoku University), Megumi Matsumoto(Graduate School of Science, Tohoku University)

11:00 AM - 11:15 AM

[PPS07-12] Multiple sulfur isotope evidence for the formation of mesosiderite meteorites

*Shun Mihira1, Madhusoodhan Satish-Kumar1, Akira Yamaguchi2, Tomohiro Usui3 (1.Department of Geology, Faculty of Science, Niigata University, 2.National Institute of Polar Research, 3.Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency)


Keywords:Mesosiderite, Sulfur isotope

Mesosiderites and HED (howaldite, eucrite, diogenite) meteorites are considered to have a common origin, from the asteroid Vesta. However, the processes that led to the origin of mesosiderites and their relation with HED's are not clear yet. In this respect, multiple sulfur isotopic composition may track their petrological relationships and suggest genetic links of mesosiderites with other meteorites. In this study, multiple sulfur isotopic composition of selected mesosiderites were measured and a comparison with othermeteorites is attempt to constrain the formation process of mesosiderites.

Although Clayton et al. (1996) suggested genetic links between pallasites, IIIAB iron meteorites, and HED meteorites based on the D17O values, the d34S and D33S relationships of the pallasites and IIIAB iron meteorites indicate that they do not match with those of HED meteorites (Rai et al., 2005; Dottin et al., 2018). The sulfur isotopic composition of mesosiderites in this study indicates similarities with IIIAB iron meteorites and pallasites but not with HED. This suggests that the sulfur isotopic composition may not preserve their true parent body information, but probably represent information on some reactions or mixing during their formation.

A recent study suggests that the formation process of mesosiderites can be explained by a hit-and-run model (Haba et al., 2019). Rai et al. (2005) has reported Mass-Independent Fractionation (MIF) for HED meteorites, however in our study the mesosiderites are devoid of MIF. This indicates two possibilities, either mixing of Vesta with the impactor or there is no genetic links between HED and mesosiderites. In our presentation we will discuss about these two possibilities on the formation process of mesosiderites using sulfur isotopic composition in comparison with the existing data of HED meteorites.

References
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2. Clayton R. N. and Mayeda T.K., Oxygen isotope studies of achondrites. Geochim. Cosmochim. Acta, 60, 1999-2017, (1996).
3. Dottin J. W., Farquhar J., and Labidi J., Multiple sulfur isotopic composition of main group pallasites support genetic links to IIIAB iron meteorites, Geochim. et Cosmochim. Acta, 224, 276-281, (2018).
4. Haba M. K., Wotzlaw J-F., Lai J-Y., Yamaguchi A., and Schonbachler M., Mesosiderite formation on asteroid 4 Vesta by a hit-and-run collision, Nature Geoscience, 12, 510-515, (2019).
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