Origin and age of  the earliest Martian crust from meteorite NWA 7533,

M. Humayun, A. Nemchin, B. Zanda, R. H. Hewins, M. Grange, A. Kennedy, J.-P. Lorand, C. Göpel, C. Fieni, S. Pont & D. Deldicque, Nature, 20 novembre 2013.

http://dx.doi.org/10.1038/nature12764