This HiRISE image shows a wonderfully complex surface on the floor of this ancient flood-carved canyon.

In this area, the water flowed from the west to the east. However, the floor does not show the kinds of landforms scientist expect from flood erosion. Instead, the floor of the valley has been covered, sometime after the flood, by some kind of flow with giant ridged plates.

Some of the plates are more than a kilometer (0.6 miles) across. The ridges appear to have formed when the solid crust on the flow was crumpled during flow. The plates are pieces of the crust that had rafted apart. Very large lava flows can produce this kind of surface, but ice and frozen mud are also capable of forming similar features.
Written by: Laszlo P. Keszthelyi

All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible: Image: NASA/JPL/University of Arizona

For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.