In this image from NASA's Mars Reconnaissance Orbiter, a group of steeply inclined light-toned layers is bounded above and below by unconformities (sudden or irregular changes from one deposit to another) that indicate a "break" where erosion of pre-existing layers was taking place at a higher rate than deposition of new materials.
The layered deposits in Melas Basin may have been deposited during the growth of a delta complex. This depositional sequence likely represents a period where materials were being deposited on the floor of a lake or running river.
The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 28.9 centimeters (11.4 inches) per pixel (with 1 x 1 binning); objects on the order of 87 centimeters (34.2 inches) across are resolved.] North is up.
https://photojournal.jpl.nasa.gov/catalog/PIA21580