11:00 〜 11:15
[PPS07-12] Multiple sulfur isotope evidence for the formation of mesosiderite meteorites
キーワード：メソシデライト、硫黄同位体
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
1. Antonelli M. A., Kim S-T., Pters M., Labidi J., Cartigny P., Walker R. J., Lyons J. R., Hoek J., and Farquhar J., Early inner solar system origin for anomalous sulfur isotopes in differentiated protoplanets, PNAS, 111, 17749-17754, (2014).
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).
5. Rai V. K., Jackson T. L., and Thiemens M. H., Photochemical mass-independent sulfur isotopes in achondritic meteorites, Science, 309, 1026-1065, (2005).
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
1. Antonelli M. A., Kim S-T., Pters M., Labidi J., Cartigny P., Walker R. J., Lyons J. R., Hoek J., and Farquhar J., Early inner solar system origin for anomalous sulfur isotopes in differentiated protoplanets, PNAS, 111, 17749-17754, (2014).
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).
5. Rai V. K., Jackson T. L., and Thiemens M. H., Photochemical mass-independent sulfur isotopes in achondritic meteorites, Science, 309, 1026-1065, (2005).