The vast canyonlands of the Colorado Plateau and Mars share great valleys and similarly colored landscapes. As on Mars, the reds and pinks of this terrestrial region are caused by oxidation of tiny iron particles. Uplift in Utah ~10 million years ago caused the Colorado River to cut canyons deep into the plateau. The origin of Valles Marineris is thought to be related to the rise of the Tharsis Bulge to the west. This uplift stressed and fractured the Martian crust, creating the 7 to 10-km-deep valley. The Mars image on the right is approximately 475 km across.