May 10, 2004
These images were taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express are of the Acheron Fossae region, an area of intensive tectonic (continental â€˜plate') activity in the past. Acheron Fossae marks the northern edge of the Tharsis plateau. It is part of a network of extensional fractures that radiates outward from their central focus in the Tharsis â€˜bulge', a huge area of regional uplift where intensive volcanic activity occurred. These curved â€˜faults' were caused in the process of this uplift: cracks in the crust formed when the hot material rising from deep in the mantle of Mars pushed the overlying â€˜elastic' lithosphere (surface layers of rock) upward. When the distorting tensions became too strong, the brittle crust on top of the lithosphere broke along zones of weakness.
Topics: Environment, Fossa, Plate tectonics, Structure of the Earth, Acheron Fossae, Planetary geology, Lithosphere, Tharsis, Crust