Some areas of Mars show a kind of selective erosion. In this image, an overlapping pit formed between one level of the surface and another. One idea is that the ground once contained significant amounts of ice in layers a few meters thick that have evaporated. Without the ice, the ground surface subsides and collapses down to a new and somewhat level surface.

Alternatively, the terrain may have been ice rich. The loss of this cement-like ice then left the surface unable to resist erosion from the wind, and allowed the surface to gradually deflate down to a new more resistant level. Either way, the current curved scarps, a few meters high between these layers may, suggest that the process is ongoing.

ID: ESP_078316_2260
date: 11 April 2023
altitude: 301 km

https://uahirise.org/hipod/ESP_078316_2260
NASA/JPL-Caltech/University of Arizona
#Mars #science #NASA