Copyright Information: All images are in the public domain and available for free. If you use this image, credit NOAA/NGDC, Colorado Geological Survey. |
"Pistol butt" trees provide evidence of active creep. The tree roots extend to material that is not moving, or is moving slowly downslope. Closer to the surface, however, the soil moves more rapidly, pushing against the trunks in a downslope direction. The trees respond by maintaining vertical growth in their upper parts, hence the curved trunks. Image Credit: Colorado Geological Survey The slopes above streams and rivers are subjected to a variety of processes that cause them to recede and retreat from the river or stream channel. These processes, collectively called mass wasting, can be classified according to rapidity of movement and according to the type of materials that are transported. |
