LITTORAL ACCUMULATIONS 



I6 3 



Littoral deposits are thickest toward the shore, thinning out to 

 an edge seaward, where they dovetail in with finer materials, be- 

 cause the coarser fragments are carried farther out at some times 

 than at others. Where, for long distances, no large rivers enter 

 the sea, the materials are all derived from the wear of the coast, 

 and the distribution of coarse and fine deposits is more regular and 

 uniform, and gravel beds may extend as far as ten miles from the 





FlG. 64. — Littoral deposits on the west coast of Greenland. The angular pieces 

 transported by ice. (Photograph by Libbey.) 



coast. The regularity of arrangement is interfered with by con- 

 flicting currents, and in eddies of quieter water will be found areas 

 of finer deposits. Beds laid down in very shallow water are apt 

 to be characterized by irregularities of stratification, known as 

 false or current bedding ; ripple marks and tracks of animals are 

 other indications of the immediate proximity of the shore. 



It will at once be evident that no great thickness of shallow- 

 water deposits can be formed, unless the sea-bottom is sinking, 

 because, otherwise, the water would soon be filled up and deposi- 



