Figure 7

Dark-field STEM image of the disordered rim in a lunar olivine grain and element profiles. A dark-field STEM image of the disordered rim in an olivine grain from lunar soil 71501 (left). The olivine grain contains solar flare tracks (red arrows) with a density similar to that in RA-QD02-0211. The disordered rim shows a similar microstructure as the Hayabusa olivine grains, except that the outermost 10 to 15 nm of the rim is dominated by vapor-deposited material enriched in Ca, Al, Ti, and Si as shown in the element profiles through the rim (right), indicated by the yellow arrow in the STEM image.