Anseris Mons Mons bedrock is actually pre-Noachian in age, perhaps dating back to over 4.1 billion years ago. The Anseris Mons massif has undergone a significant amount of erosion since it was uplifted. The flanks of the mountain have huge triangular re-entrants and associated spurs, which give the massif a broad, pyramidal shape. The re-entrants were likely produced through a variety of mass-wasting and periglacial/glacial processes. A large cirque-like re-entrant with channelized debris aprons or fans is present on the south side of the mountain. Anseris Mons Anseris Mons is an isolated massif (mountain) in the southern highlands of Mars, located at
Olympus Mons three large Martian shield volcanoes, collectively called the Tharsis Montes (Arsia Mons, Pavonis Mons, and Ascraeus Mons). The Tharsis Montes are slightly smaller than Olympus Mons. A wide, annular depression or moat about deep surrounds the base of Olympus Mons and is thought to be due to the volcano's immense weight pressing down on the Martian crust. The depth of this depression is greater on the northwest side of the mountain than on the southeast side. Olympus Mons is partially surrounded by a region of distinctive grooved or corrugated terrain known as the Olympus Mons aureole. The aureole consists of