294 



FIRST YEAR SCIENCE 



mud and debris accumulate. Thus low shores are slowly 

 being built out into the sea. Shore borders of this kind 

 are found extending many miles along the coasts of 

 southern Florida and Texas and in many other places. 



In extreme northern and southern latitudes the coast 

 may be fringed for long distances with ice. In middle 

 latitudes, however, the coast is generally composed of rock, 



FINGAL'S CAVE. 



sand or mud and is sometimes protected by a thick sea- 

 weed mantle. Here, besides the usual forces of erosion 

 and deposition found active on the land, are the forces of 

 the waves and currents. 



139. Wave Cutting. Wherever the waves strike on an 

 unprotected shore, they wear it away. The rapidity of 

 the cutting and the forms carved depend upon the 

 strength of the waves and the kind of shore. Wherever 

 there is a point of weakness along the shore, there the 

 waves cut back more rapidly. The harder parts stand 



