This observation shows wrinkle ridges in Hesperia Planum. Hesperia Planum encompasses a region of over two million square kilometers (over 770,000 square miles) in the southern highlands of Mars. It is located northwest of the Hellas basin and adjacent to Tyrrhena Patera and contains abundant orthogonal and intersecting wrinkle ridges.
Wrinkle ridges are linear to arcuate positive relief features and are often characterized by a broad arch topped with a crenulated ridge. These features have been identified on many planets such as the Moon, Mars, Mercury, and Venus. On Mars, they are many tens to hundreds of kilometers long, tens of kilometers wide, and have a relief of a few hundred meters. They commonly have asymmetrical cross sectional profiles and an offset in elevation on either side of the ridge.
Wrinkle ridges are most commonly believed to form from horizontal compression or shortening of the crust due to faulting and are often found in volcanic plains.Written by: Maria Banks (13 December 2007)
More info and image formats at http://hirise.lpl.arizona.edu/PSP_006223_1600
Image: NASA/JPL/University of Arizona