This image shows Martian dissected mantle terrain in the Tempe Terra region, located on the northeastern flank of the Tharsis volcanotectonic province.

The dissected mantle terrain is observed between 30 and 60 degrees of latitude in both hemispheres of Mars. This mantle terrain is commonly believed to be young and to consist of a thin layer of an ice-dust mixture, perhaps deposited during the last periods of high obliquity. Martian dissected mantle terrain is often characterized by various erosional features, such as scalloped depressions that give it a pitted or dissected texture.

The presence of scalloped pits has led to hypotheses of the removal of subsurface material, such as interstitial ice, by sublimation (ice going directly from the solid state to the gas state). Their formation most likely involves development of oval-to scalloped-shaped depressions that may coalesce together, leading to the formation of large areas of pitted terrain. Scalloped pits typically have a steep pole-facing scarp (north in this observation) and a shallower equator-facing slope.

Formation of scalloped depressions may be a process that is still active today.

Written by: Maria Banks   (29 April 2008)

More info and image formats at http://hirise.lpl.arizona.edu/PSP_007930_2310

Image: NASA/JPL/University of Arizona