Large Landslide Deposit
This HiRISE image is centered on a large landslide which formed the large lobe at the base of the steep slope. This is material which was transported in a massive rock-slide.
The landslide has several ridge-and-trough lineations in the direction of the flow. These occur in similar landslides on Earth as well. Comparing these features on Mars with similar examples on Earth helps geologists better understand how they work on both planets.
In this case, the slide is relatively old. The material has many impact craters superimposed. The steep slope, which was the source of the landslide, has undergone further erosion, so the landslide source area is no longer clear.