Multi-Elevation Gullies

Gullies probably formed along the bouldery layers in the upper slopes of this unnamed crater within the last few million years. Gullies eroded these crater slopes and transported sediment downslope forming debris aprons multiple times. These older apron surfaces were cut by numerous fractures running perpendicular to the slope. Subsequent episodes of gully activity eroded through these fractures and deposited new aprons. On the floor of the crater are ridges with bouldery layers. These ridges may mark the furthest extent of glaciers that predate much of the original gully activity. Bright flows continue to form in these gullies seasonally. In the upper gully regions, long shadows cast by jagged outcrops allow scientists to determine the heights and depths of landforms by measuring the length of the shadows cast by the ridges onto the gully floor. https://photojournal.jpl.nasa.gov/catalog/PIA23020