Elysium Mons is a large shield volcano on the opposite side of Mars from Olympus Mons and the other giant Tharsis volcanoes. Like its siblings in Tharsis, Elysium Mons is covered with lava flows.

The lower parts of Elysium Mons are also cut by large sinuous channels (or "rilles"). Features like these can be found on the Moon, where they were carved by lava. On Mars, there has been some suggestion that water, rather than lava, was responsible for the erosion.

This HiRISE image is covers a location where three different sinuous rilles (running generally west to east) come together and are then cut by a pair of faults (running roughly north-south). The ground has pulled apart and dropped down in between these two faults, forming a depression that geologists call a "graben."?? Where there was more focused ground collapse, small depressions (or "pit craters") formed. The thick coating of dust makes it hard to tell what fluid last ran through the sinuous rilles in this location. However, the layers of hard rock that can be occasionally seen poking through the dust indicate that what they eroded, was a stack of lava flows.
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.