Northern Hemisphere Ice Cap (False Colors; credits: Lunexit)

This image shows layering within the Northern Hemisphere Ice Cap, which probably reflects seasonal variability in accumulation of the ice versus sublimation (going from solid to a gas).
The presence of sand dunes indicates transport of sedimentary materials by wind. Erosion of layering is apparent as a series of undulating ridges at the transition between the Layered Terrain and the Dune-Field.

Near the top of the image several vents occur where materials from the shallow subsurface are erupted onto the surface.