Mars: lithosphere, hydrosphere and atmosphere

Mars is the only inner solar system planet with an observed hydrological cycle and by inference, the potential for life. As such, the surface and atmospheric process acting on Mars have been the focus of billions of dollars in rovers, landers, and orbiters. However, martian meteorites are key objects to understand the formation and the evolution of Mars.

Project overview

This project seeks to identify subtle Martian geochemical signatures via in-situ analyses of individual minerals in different Martian meteorites.

Project description

Traditional bulk analyses homogenize samples and lose valuable geochemical mixing end-members that are present in an individual sample due to complex mixing processes during crystallization, alteration on the Martian surface, and/or ejection from Mars. Specifically, geochemical end-members preserved in Martian meteorites can identify the geographic expanse of source regions for Martian meteorites, evaluate the heterogeneity of the Martian mantle, identify atmospheric and hydrologic processes acting on the surface of Mars, potentially identify any biological activity recorded in these meteorites, and, importantly, establish a data base of geochemical signatures. Due to the extremely complex nature of these samples, the aforementioned project goals can only be accomplished by in-situ geochemical analytical techniques that are available at NordSIMS facility here at the Museum.

Selected publications

Bellucci, J.J., Nemchin, A.A., Whitehouse, M.J., Humayun, M., Hewins, R., and Zanda, B. (2015a) Pb-isotopic evidence for an early, enriched crust on Mars. Earth and Planetary Science Letters. 410: 34-41 (https://doi.org/10.1016/j.epsl.2014.11.018) External link.
Bellucci, J.J., Nemchin, A.A., Whitehouse, M.J., Snape, J.F., Bland, P.A., Benedix, G.K. (2015b) The Pb isotopic evolution of the Martian mantle constrained by initial Pb in Martian meteorites Journal of Geophysical Research-Planets. 120: 2224-2240 (https://doi.org/10.1002/2015JE004809 External link.)
Bellucci, J.J., Nemchin, A.A., Snape, J.F., Whitehouse, M.J., Kielman, R.B., Bland, P.A., Benedix, G.K. (2016) A Pb isotopic resolution to the Martian meteorite age paradox. Earth and Planetary Science Letters. 433: 241-248 (https://doi.org/10.1016/j.epsl.2015.11.004 External link.)
Bellucci, J.J., Whitehouse, M.J., John, T., Nemchin, A.A., Snape, J.F., Bland, P.A., and Benedix, G.X. (2017) Halogen and Cl isotopic systematics in Martian phosphates: Implications for the Cl cycle and surface halogen reservoirs on Mars. Earth and Planetary Science Letters. 458, 192-202 (https://doi.org/10.1016/j.epsl.2016.10.028) External link.
Bellucci, J.J., Whitehouse, M.J., Nemchin, A.A., Snape, J.F., Kenny, G.G., Merle, R.E., Bland, P.A. and Benedix, G.K., 2020. Tracing martian surface interactions with the triple O isotope compositions of meteoritic phosphates. Earth and Planetary Science Letters, 531, p.115977(https://doi.org/10.1016/j.epsl.2019.115977) External link.
Bellucci, J.J., Herd, C.D.K., Whitehouse, M.J., Nemchin, A.A., Kenny, G.G. and Merle, R.E., 2020. Insights into the chemical diversity of the martian mantle from the Pb isotope systematics of shergottite Northwest Africa 8159. Chemical Geology, 545, p.119638 (https://doi.org/10.1016/j.chemgeo.2020.119638) External link.