HiRISE: Boulders on a landslide

The striking feature in this image is a boulder-covered landslide along a canyon wall. Landslides occur when steep slopes fail, sending a mass of soil and rock to flow downhill, leaving behind a scarp at the top of the slope. The mass of material comes to rest when it reaches shallower slopes, forming a lobe of material that ends in a well-defined edge called a toe. (Take a look at the anaglyph to compare the steep cliff and landslide scarp to the relatively flat valley floor. ) [More at link]