Mass wasting along the walls of Valles Marineris has produced some of the most spectacular landslides observed anywhere. Surface and near-surface processes that occur in the vicinity of former and existing ice regions are referred to as periglacial processes. Although periglacial features and related phenomena have not been positively identified on Mars, it is reasonable to expect them in view of the low temperatures and the probable existence of subsurface ice in some regions. Sand Dunes and Landslides in Valles Marineris . In this region, the walls have been modified by landslides.
Debris flows are numerous, as are jumbled masses of debris below the cliffs.
Wind may be an effective agent in removing debris that has slumped into the canyon. The canyon thus enlarges itself by the combined processes of slumping and wind excavation. An enlargement of the dune field on the preceding picture is presented here to show individual dunes about 500 meters across. The wind appears to have been blowing from the west and leading dunes to the east appear to climb the canyon wall. Landslide in Noctis Labyrinthus .