Eastern Tithonium Chasma forms just one branch of the vast Valles Marineris canyon complex created within the last 3 billion years. Valles Marineris is over 4000 kilometers long, wider than the United States. Tithonium Chasma is 50 kilometers wide and over 6 kilometers deep in this area. In comparison, the Grand Canyon (slide #12) is about 175 kilometers long, 30 kilometers wide, and only 2 kilometers deep. Many martian canyon-forming processes are illustrated in this view. The canyons were initiated by extensional fracturing and pulling apart of the crust during the uplift of the vast Tharsis plateau. Landslides (at top center) have enlarged the canyon walls and created hummocky debris deposits on canyon floors. Sapping by groundwater has created numerous finger-shaped side canyons (at bottom center). A thick layered deposit, possibly lake deposits or an ancient airfall, later formed in the center of the canyon. These sediments have been eroded by winds into sculpted deposits (bright material at center). Minor volcanic or hydrothermal activity may have formed bright and dark deposits on the floors of some canyons.
1 images 063A44, 065A21.