HiRISE: Crater straddling two terrain units

An approximately 1-kilometer impact crater located in northern Sinus Meridiani has formed along the boundary of two different terrain units. The western part of the crater has formed along a unit consisting of wind-blown basaltic materials that overlie light-toned units exposed in the crater wall. To the east is a shallow circular depression several kilometers across that consists of multiple layers of light-toned deposits that have been eroding away. These deposits are bright in THEMIS night-time infrared and dark in day-time infrared… [More at link]