Mangala Fossae

The linear depression in this VIS image is called Mangala Fossae. The depression is 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. Located between Terra Sirenum and Daedalia Planum, Mangala Fossae is 828 km long (514 miles).