Crommelin Crater in northwest Meridiani Planum is a large structure which contains light-toned material with layered and stepped buttes.
The highlighted subimage here shows a small crater. The impactor appears to have penetrated some layers which we can see exposed. Other areas in this part of the image are covered by dust (which appears relatively blue in this representation). The layering may have been the result of sedimentation early in the history of Mars.
Written by: Nicolas Thomas (audio by Tre Gibbs) (5 September 2012)
This is a stereo pair with ESP_017765_1850 .
More info and image formats at http://hirise.lpl.arizona.edu/ESP_017343_1850
Image: NASA/JPL/University of Arizona