DEPOSITION IN THE SEA 245 
Variation in Sediments along the Shore. — Starting 
on the coast of Maine and proceeding to the mouth 
of the Rio Grande, we find what at first seems an 
interminable and unintelligible variety of sediment 
along the shore. In Maine, bare, rocky headlands 
alternate with pebbly and sandy beaches; on some of 
the beaches the pebbles are small, on others real 
bowlders (Fig. 135); on some they are of one kind of 
rock, on others 
entirely different. 
In places there 
are sand beaches 
(Fig. 51), and in 
some of the bays 
or harbors: there 
is a sediment of [iia ae 
the finest clay 3 Fig. 136. 
(Fig. 156); and Mud flats, Bay of Fundy, exposed at low tide. 
here, along this 
irregular coast, there is every variety of deposit, from 
the coarsest to the finest; but the average is coarse. 
On Cape Cod, and from Sandy Hook to the southern 
part of Florida, pebbly beaches are replaced by sandy. 
Nearly this entire coast is a sand-bound shore, with 
here and there stretches of clay where the action of the 
waves is slight. Not only have the waves thrown up 
bars, but the wind has added to their elevation by 
