Space weathering on airless planetary bodies: clues from the lunar mineral hapkeite - PubMed (original) (raw)

Space weathering on airless planetary bodies: clues from the lunar mineral hapkeite

Mahesh Anand et al. Proc Natl Acad Sci U S A. 2004.

Abstract

Physical and chemical reactions occurring as a result of the high-velocity impacts of meteorites and micrometeorites and of cosmic rays and solar-wind particles are major causes of space weathering on airless planetary bodies, such as the Moon, Mercury, and asteroids. These weathering processes are responsible for the formation of their regolith and soil. We report here the natural occurrence of the mineral hapkeite, a Fe2Si phase, and other associated Fe-Si phases (iron-silicides) in a regolith breccia clast of a lunar highland meteorite. These Fe-Si phases are considered to be a direct product of impact-induced, vapor-phase deposition in the lunar soil, all part of space weathering. We have used an in situ synchrotron energy-dispersive, single-crystal x-ray diffraction technique to confirm the crystal structure of hapkeite as similar to the structure of synthetic Fe2Si. This mineral, hapkeite, is named after Bruce Hapke of the University of Pittsburgh, who predicted the presence and importance of vapor-deposited coatings on lunar soil grains some 30 years ago. We propose that this mineral and other Fe-Si phases are probably more common in the lunar regolith than previously thought and are directly related to the formation of vapor-deposited, nanophase elemental iron in the lunar soils.

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Figures

Fig. 1.

Reflected-light image of an area in the regolith clast in Dhofar 280, showing distribution of FeNi metal and Fe-Si metal grains in a feldspathic matrix, Msk, Maskelynite.

Fig. 2.

Backscatter electron (BSE) and x-ray elemental maps of hapkeite. Intergrowths of FeSi phase are seen in the lower part of hapkeite.

Fig. 3.

Cartoon illustrating the formation of iron-silicides on the Moon.

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References

1. Taylor, L. A. & Cirlin, E.-H. (1985) in ESR Dating and Dosimetry, eds. Ikeya, M. & Miki, T. (Ionics, Tokyo), pp. 19-39.
1. Morris, R. V. (1980) Proceedings of the 11th Lunar Planetary Science Conference (Pergamon, New York), pp. 1697-1712.
1. Zhu, X. K., Guo, Y., O'Nions, R. K., Young, E. D. & Ash, R. D. (2001) Nature 412, 311-313. - PubMed
1. Wiesli, R. A., Beard, B. L., Taylor, L. A. & Johnson, C. M. (2003) Earth Planet. Sci. Lett. 216, 457-465.
1. Keller, L. P. & McKay, D. S. (1997) Geochim. Cosmochim. Acta 61, 2331-2341.

Space weathering on airless planetary bodies: clues from the lunar mineral hapkeite - PubMed (original) (raw)