This image shows a small portion of the floor of Coprates Chasma, a large trough within the Valles Marineris system of canyons.
Although the exact sequence of events that formed Coprates Chasma is unknown, the ripples, mesas, and craters visible throughout the terrain point to a complex history involving multiple mechanisms of erosion and deposition. The main trough of Coprates Chasma ranges from 60 to 100 kilometers in width. [More at link]