A powerful combination of tectonic activity and strong winds have joined forces to shape the scenery in this region of Mars. The image was taken by ESA’s Mars Express on 7 July 2015 and covers part of the Aeolis Mensae region. It straddles the transitional region between the southern hemisphere highlands and the smooth, northern hemisphere lowlands.
Several fracture zones cross this region, the result of the martian crust stretching apart under tectonic stress. As it did so, some pieces of the crust sheared away and became stranded, including the large block in the centre of the image.
This flat-topped block, some 40 km across and rising some 2.5 km above the surrounding terrain, is one such remnant of the crust’s expansion. Its elevation is the same as the terrain further to the south, supporting the idea that it was once connected.
Over time, the stranded blocks and their associated landslides have been eroded by wind and possibly flowing water. [More at link]