222 



PHYSICAL GEOLOGY 



Fig. 214. — Formation of barrier islands or sand reefs. These are built near the 

 line of breakers, off shallow, sandy shores. The lagoon in 214 B is shown to be nearly 

 filled with sediment and organic matter. 



a lagoon between it and the first reef. One of the most remarkable 

 barrier beaches is off the coast of Texas and extends without a break 

 for a hundred miles. 



On the Atlantic coast of North America, from New Jersey south, 

 the barrier beaches are so well-developed that it has been proposed 

 to make a protected waterway by deepening the lagoons back of them. 

 If this is accomplished, vessels will be able to sail from New York to 



Florida, practically free 

 from storm waves, being 

 protected almost the en- 

 tire distance by sand 

 reefs. The barrier 

 beaches off the coast of 

 New Jersey are especially 

 favored as pleasure re- 

 sorts because of their 

 mild temperature in win- 

 ter and cooling breezes in 

 summer. In some places 

 the barriers are growing 

 and in others they are 

 being washed away. 

 Whether they grow or 

 waste depends upon 



215. — Barrier beaches on the coast of 

 I cxas. Matagorda Bay has been formed by a 

 barrier beach, and Galveston is situated on one. 



