Hanging Valleys

Hanging valleys are fluvial (stream) valleys that flow into a glacial trough.  Fluvial valleys in mountainous areas generally have steep slopes, so their cross-sections will be V-shaped.  The water in the stream will have dumped out onto the glacial ice.  The glacier had more erosional power than the stream, and so the glacial valley will be cut deeper than the fluvial valley.  So, hanging valleys are V-shaped (fluvial) valleys which were NEVER glaciated that join a glacial trough or U-shaped valley.  The difference in the elevation of the base of the two valleys often results in a water fall.

                  

This photo was taken in the glacial trough leading to Snowbird, Utah near Salt Lake City.  The V-shape is outlined in the right hand copy.