Claritas Fossae

Located between the lava plains of Daedalia Planum and Solis Planum, Claritas Fossae is a graben filled highland. Graben are formed by tectonic activity, where extensional forces stretch the surface forming faults. When large amounts of pressure or tension are applied to rocks on timescales that are fast enough that the rock cannot respond by deforming, the rock breaks along faults. In the case of a graben, two parallel faults are formed by extension of the crust and the rock in between the faults drops downward into the space created by the extension. These linear grabens are termed fossae. This region of Mars had very active tectonism and volcanism, resulting in the huge volcanos like Arsia Mons and deep chasmata of Valles Marineris. Claritas Fossae was formed prior to the large lava flows of the Tharsis region.