This image shows a large outcrop of layered rock in Aureum Chaos, an area that has apparently collapsed, leaving a region of irregular knobs and hills. Unlike many of the knobs, the light outcrop shows distinct, nearly horizontal layers. This may indicate that it was deposited after the collapse of the Chaos.

Multiple layers are exposed in the outcrop, which is several kilometers long. The best exposures, in the north wall, reveal multiple different rock units with different color and texture. The bottom unit is very light-toned and shows little internal structure other than occasional fractures. Above this is a darker unit with a broken appearance, followed by fine, stepped layers. The top of the outcrop consists of knobs and spires that may be eroded remnants of the top of the stack. Many of the units show variations in color which could indicate further divisions.

This package of rocks may have been deposited by multiple processes. Alternatively, the same process could have delivered sediments from different sources. Some possible origins include dust or volcanic ash settling from the atmosphere, wind-blown sand, or material deposited in lakes.

Written by: Colin Dundas

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.