Mangala Fossae

Mangala Fossae is a long linear depression called a graben and was formed by extension of the crust and faulting. 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. At the right side of the image the graben enters an impact crater, and creates a complex group of tectonic fractures and depressions. Mangala Fossae is 828 km long (514 miles).