Cerberus Fossae

Today’s VIS image shows a section of Cerberus Fossae. Cerberus Fossae are located in Elysium Planitia, southeast of the Elysium Mons volcanic complex. The linear features in the image are tectonic graben. Graben are 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. Two graben are visible in this THEMIS image, trending from west-northwest to east-southeast. Because the faults defining the graben are formed perpendicular to the direction of the applied stress, we know that extensional forces were pulling the crust apart in the north-northeast/south-southwest direction. The Cerberus Fossae graben are sources of both channels and significant volcanic flows. The rough surface around the graben is thought to be volcanic flows. Cerberus Fossae cuts across features such as hills, indicating the relative youth of the tectonic activity.