Knobbly Textured Sandstone on Mount Sharp, Mars

Patches of Martian sandstone visible in this view from NASA Curiosity Mars rover have a knobbly texture due to nodules apparently more resistant to erosion than the host rock in which some are still embedded.

Patches of Martian sandstone visible in this view from NASA Curiosity Mars rover have a knobbly texture due to nodules apparently more resistant to erosion than the host rock in which some are still embedded.