Noctis Labyrinthus (Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)

This image spans the floor and two walls of a pit in Noctis Labyrinthus, a System of deep, steep-walled Valleys on the Western Edge of Valles Marineris.

The Valleys themselves are tectonic features known as "Graben" (---> trench-like features that form in response to extension (or stretching) of the Crust). In the case of Noctis Labyrinthus, volcanic activity in the Tharsis Region may have formed a bulge, which then stretched and fractured the Crust above it.