WIND EROSION 137 
see a softer layer cut into a series of caves, because 
the wind action is more effective in carving the soft 
layer (Figs. 66 and 91). Not merely are fragments 
thrown against the cliffs, but also the removal of 
particles prepared by weathering, and nearly ready to 
fall, is promoted by the wind action. In arid regions, 
Fic. 66. 
A view in the arid lands, showing scanty vegetation, and a cliff open to the attack 
of the wind. The cliff is sculptured by this action, and the wind has prevented 
a talus from accumulating at its base. 
where rain and the ordinary agents of weathering have 
little power, the wind becomes one of the most impor- 
tant causes of destruction. 
Not only is sand accumulated on the land, but it 
is often blown into the lake, river, and sea. From 
the river it may enter the ocean, and thus aid in the 
