This HRSC image shows the scarps demarking the boundary between the layered deposits covering the north polar region of Mars and the lower surrounding terrain exhibiting large dune fields. The North Polar layered deposits represent a up to 3-kilometer thick stack of dusty water ice layers, about 1000 kilometers across. The layers record information about the climate, stretching back a few million years into Martian history. The deposits are formed by atmospheric fallout of dust and water ice and direct frost condensation. They are characterized by continuous sub-horizontal layers, mostly composed of water ice and of up to 10-15% fine dust sediments. It is important to mention, that the north polar ice cap of Mars also shows a thin, 1 to 2 m thick seasonal cap of dry ice (CO₂) which in summer completely sublimates into the atmosphere.