Lidar hillshade image of several large, prehistoric rock avalanche-style failures along Catawba Mountain in the Appalachian Valley and Ridge of southwest Virginia

Detailed Description
Several large, prehistoric rock avalanche-style failures have occurred along Catawba Mountain in the Appalachian Valley and Ridge of southwest Virginia.
The failures displaced large masses of Siluro-Devonian sandstones which detached in weaker underlying Silurian and uppermost Ordovician shales. Very steep dip of bedding (approaching 60 degrees) along this portion of the ridge appears to have forced the slide mass across the flattening failure surface very rapidly, disaggregating the mass and producing high mobility. The slide at center is 840 m (2,740 ft) long from headscarp to deposit toe.
USGS-sourced lidar hillshade image draped across Google Earth topography.
Sources/Usage
Public Domain.