In this beautiful image there appears to be a breccia layer, or a layer composed of rock fragments embedded in a finer material. This particular breccia is made up of fragments (or "clasts" as they are known to geologists) so large they can be seen by HiRISE.
The breccia layer, seen most easily near the center of this image, seems to be more resistant to erosion than the surrounding material, serving as a caprock to protect the layers beneath it.
The HiRISE team is planning on acquiring another image over this area in order to create a stereo (3-D) pair. This will help scientists better understand the topography and stratigraphy of the area.
This is a stereo pair with ESP_026523_1735.
Photo credit: NASA/JPL/University of Arizona
Note: This image is located in western Candor Chasma to the east of Ceti Mensa.