The target of this observation is a circular depression in a dark-toned unit associated with a field of cones to the northeast.
At the image scale of a Context Camera image, the depression appears to expose layers especially on the sides or walls of the depression, which are overlain by dark sands presumably associated with the dark-toned unit. HiRISE resolution, which is far higher than that of the Context Camera and its larger footprint, can help identify possible layers.
This caption is based on the original science rationale.
Written by: HiRISE Science Team (audio: Tre Gibbs) (8 April 2015)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_039581_1520
Image: NASA/JPL/University of Arizona