The Acheron Fossae region is named after Acheron Fossae, an approximately 800 km long tectonic graben system about 1200 km north of Olympus Mons on the outskirts of its aureole. This region appears as a block of ancient terrain surrounded by younger plains in form of a reversed crescent moon on the Martian surface. The HRSC image frames the eastern part of the Acheron Fossae region where the edge of the graben system leads into the lower plains.

The Acheron Fossae graben system has a typical "Horst and Graben" morphology formed by extensional crustal deformation in the Noachian period 3.7-3.9 billion years ago. Several parallel faults (graben) have formed caused by the downward movement of the crust relative to the blocks on either side (horst). These diverging movements of crustal blocks indicate tensional forces in the crust during the time when Mars was more active. During geological evolution the graben have been filled with different material such as glacial and volcanic deposits.

The lower plains show a smooth surface, while the graben system exhibits a rugged and cratered surface. Some of the plains material appears slightly darker and shows only few impact craters. The darker material displays lobate flow-like features (see annotated image). Lobate debris aprons can be spotted around the edges of the grabens. These geomorphological features are indicative of the deposition and movement of volatile-rich material and are thought to represent rock glaciers or debris-covered glaciers while the lobes indicate the flow trend.

The second plains material is slightly lighter in color and shows more impact craters on its surface. Here, the viscous flow pattern is not observed. This deposit is interpreted as lava flows from Alba Patera, one of the large Martian shield volcanoes east of Acheron Fossae that buried the roughly 28 km wide impact crater in the center of the image (see annotated image).

Another intriguing feature found in the HRSC observation is a set of three conical topographic peaks several km in height (see annotated image). These formations are interpreted as volcanic domes created by rift-related volcanism and driven by local magmatic uplift. Partly, the volcanic domes are cut by faults, which could indicate tectonic activity after their formation.