Long Shadows over Ariadnes Colles (edm - natural colors; credits: Lunexit)

This edm shows one of the hills in detail.

The hill appears criss-crossed by long fractures and most of them made apparent by the shadows they cast.
The shadows indicate that the fractures “stick out” from their surroundings, and hence that they are more resistant to erosion. In terrestrial environments this occurs when fluids flow along the fractures, leaving behind cementing minerals or when fractures are filled by igneous materials.