Ridges in Lycus Sulci
This image shows a group of curved ridges in an area called Lycus Sulci, which is located near the Olympus Mons volcano. Much of the rocks in this area have been subjected to erosion (e.g., scouring and removal) by the wind, so that the surface we see today was originally buried deep underground.
Ridges such like these typically form underground through diagenesis, a process where water flows underground and minerals start to form from chemicals within the groundwater. These minerals are typically most abundant in places such as cracks, where the water can easily flow and minerals have room to grow. The mineral-filled cracks are more difficult to erode than the surrounding rocks and thus can form ridges such like these when the weaker surrounding rocks are eroded away.
The map is projected here at a scale of 50 centimeters (19.7 inches) per pixel. (The original image scale is 55.9 centimeters [22.0 inches] per pixel [with 2 x 2 binning]; objects on the order of 168 centimeters [66.1 inches] across are resolved.) North is up.
The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.