Chaos

In planetary nomenclature, the descriptor term chaos means "distinctive area of broken terrain". The general morphology of chaos is steep-sided mesas in close proximity. The initial breakup of the land is due to tectonic forces, although the release of subsurface water may play are part. With time and erosion the valleys widen and the mesas grow smaller. This image shows a region of chaos on the eastern edge of Arabia Terra, just north of the mouth of Mawrth Vallis.