... concentric crater fill and ejecta deposits.
The upper left flat-floored crater shows a distinct radial ejecta layer with many stripes and measures roughly 22 km in diameter. Compared to the other large craters, it appears to be the youngest. The smaller crater to its left still hosts some of the ejecta of the larger crater. The 22 km crater shows a so-called concentric crater fill. This is a common landform in the Martian mid latitudes (30°-60° N and S) and describes a crater filling deposit with an approximately concentric pattern. It develops when debris masses very slowly flow down along parts or all parts of the crater wall, often converging at or near the center of the crater floor. The debris is mixed with ice that condensed from the atmosphere. The smaller craters on the right side of the HRSC observation also show a ice-rich crater fill, however not concentric, but lobate. The distinct rims also indicate a younger age of these craters.