This high-resolution MGS MOC image shows overlapping landslide deposits at the foot of the wall in the Ganges region of the Valles Marineris canyon complex on Mars. PSI's Bill Hartmann is currently collaborating with French researcher Cathy Quantin to use the landslide data to examine the time behavior of cratering on Mars, and the implications for using small craters to date landform features. The younger (overlying) debris fan has a distinctly lower crater density of small craters than the older (underlying) deposit. The relationship shown here argues against recent suggestions that crater densities of small craters are so completely dominated by statistical clustering of "secondary" ejecta craters that they are useless for dating.