Although Valles Marineris originated as a tectonic structure, it hasbeen modified by other processes. This image shows a close-up view of alandslide on the south wall of Valles Marineris. This landslide partiallyremoved the rim of the crater that is on the plateau adjacent to VallesMarineris. Note the texture of the landslide deposit where it flowed acrossthe floor of Valles Marineris. Several distinct layers can be seen in thewalls of the trough. These layers may be regions of distinct chemical compositionor mechanical properties in the Martian crust. (Credit: Calvin J. Hamilton,LPI, and NASA)