The Summit of Olympus Mons

Bold scarps and extensional features (graben) record multiple stages of caldera collapse at the summit of Olympus Mons. The wrinkle ridges are contractional features, and probably formed during the cooling of an ancient lava lake, prior to the collapse events. Olympus Mons is the largest volcano in our solar system, reaching heights of over 40 km tall from base to summit, with the base covering an area as large as the state of Arizona.