Ophir Chasma forms the northern portion of Valles Marineris, and this image features a small part of its wall and floor.
The wall rock shows many sedimentary layers and the floor is covered with wind-blown ridges, which are intermediate in size between sand ripples and sand dunes. Rocks protruding on the floor could be volcanic intrusions of once-molten magma that have pushed aside the surrounding sedimentary layers and “froze” in place. [More at link]