A big channel on Ascraeus Mons

Caption NASA originale:"This MGS-MOC image shows a portion of a deep Channel formed on the Northern Flank of the large Volcano, Ascraeus Mons. Layers of Volcanic Rock are exposed in the Channel Walls, and the dark dots on the Valley Floor are Boulders derived from erosion of these materials.
The picture occurs near 14,5° North Lat. and 102,8° West Long. and is illuminated from the lower left. The picture covers an area about 3 Km (1,9 mi) across".