The volcanic vent northeast of Rachmaninoff basin is framed perfectly in this image. The surface in some regions appears smooth, having been blanketed by very fine particles ejected explosively from the vent. Other regions, like those in the right hand side of the depression, exhibit more texture indicating a younger age. The textured walls indicate downslope movement of material, and a bright horizontal layer just beneath the surface can be traced along much of the northeastern wall. http://photojournal.jpl.nasa.gov/catalog/PIA19223