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
Ascraeus Mons zone of knobby terrain outlined by a semicircular zone of concentric ridges. Similar deposits are also found at the northwestern edges of the other two Tharsis Montes, Pavonis Mons and Arsia Mons, as well as on Olympus Mons. The FSD at Ascraeus Mons is the smallest of those on the Tharsis Montes, covering an area of 14,000 km and extending outward from the volcano's base for about 100 km. The origin of these deposits has been debated for decades. However, recent geologic evidence suggests that FSDs are deposits left by glaciers, which covered portions of the volcanoes during a recent