This observation shows the remnants of a thick deposit that once covered much of the Electris region of Mars.

The deposit is generally bland in appearance, but shows subtle indications of layering. Where exposed along scarps, the deposit appears to be uniformly fine-grained and yields little in the way of blocky talus (rock debris) upon erosion. The origin of this deposit remains uncertain, but the fairly uniform and fine-grained nature suggests deposition of sediments by the wind is one possibility.Written by: John Grant   (8 September 2007)

More info and image formats at http://hirise.lpl.arizona.edu/PSP_004981_1435

Image: NASA/JPL/University of Arizona