Steve Halla’s class at Leap Academy Charter High School in Camden, NJ, suggested this image, a region near the intersection of Elysium Chasma and Hyblaeus Chasma. The class suggested that seeing a cross-section of Hyblaeus Chasma in the walls of Elysium Chasma might shed light on the mechanism(s) that formed it.

A cross-section of Hyblaeu Chasma is visible in the first subimage. The chasm seems to be filled with a resistant light-toned layer, about 200 meters thick (likely consisting of cemented windblown sand and dust) forming a mantling unit and overlying more resistant boulder-rich layers. The sand and dust was likely blown into Hyblaeu Chasma after it was formed by tectonic processes, possibly in combination with fluvial processes. The chasmata were subsequently broadened by hillslope erosion: boulders are strewn along the top of this dusty mantling unit. Slumping, possibly caused by faulting, along the southern wall of Hyblaeus is visible at the intersection with Elysium Chasma.

This image also shows a number of dark streaks along the walls of Elysium Chasma, further to the south. One fresh-appearing streak divides around a slight ridge in the second subimage (about 1 kilometer across). Other smaller, fainter, possibly older streaks have formed on either side of this ridge, producing a herringbone-like pattern. A number of explanations have been suggested for these streaks, including the idea that they are formed by dry avalanches of dust.

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.