Blackhawk Landslide, California

The Blackhawk landslide, Lucerne Valley, California, is a lobe of marble breccia, 10 to 30 m thick, 3 km wide, and nearly 8 km long. Geologic evidence shows that the rockslide came down the gently inclined slope as a nearly monolithic sheet moving more than 100 km per hour. The accepted hypothesis is that the slide was lubricated by a layer of compressed air. At least two earlier similar but smaller rockslides have occurred in the area. The south-looking perspective view image was acquired on September 22, 2014, and is located at 34.4 degrees north, 116.7 degrees west.

http://photojournal.jpl.nasa.gov/catalog/PIA21008