and is correspondingly variable in littoral materials. Hov«ver, beaches are 

 generally narrow, steep, and coarse-grained; they commonly lie at the base of 

 sea cliffs (Sellman, et al., 1971, p. D-10). Quartz sand is less common and 

 gravel more common here than on many other U.S. coasts. 



e. Hawaii . Much of the Hawaiian islands is bounded by steep cliffs, but 

 there are extensive beaches. Littoral materials consist primarily of bedrock, 

 and white sand formed from calcium carbonate produced by marine inverte- 

 brates. Dark-colored basaltic and olivine sands are common where river mouths 

 reach the sea (Shepard and Wanless, 1971, p. 497; U.S. Army Corps of 

 Engineers, 1971). 



f. Great Lakes . The U.S. coasts of the Great Lakes vary from high bluffs 

 of clay, shale, and rock, through lower rocky shores and sandy beaches, to low 

 marshy clay flats (U.S. Army Corps of Engineers, 1971, p. 13). The littoral 

 materials are quite variable. Specific features are discussed, for example, 

 by Bowman (1951), Hulsey (1962), Davis (1964), Bajorunas and Duane (1967), 

 Berg and Duane (1968), Saylor and Upchurch (1970), Hands (1970), Corps of 

 Engineers (1953a, b and 1971), and U.S. Army Engineer District, Milwaukee 

 (1953). 



6. Sampling Littoral Materials . 



Sampling programs are designed to provide information about littoral 

 materials on one or more of the following characteristics: 



(a) Typical grain size (usually median size) . 



(b) Size distribution. 



(c) Composition of the littoral materials. 



(d) Variation of (a), (b), and (c), with horizontal and vertical 

 position on the site. 



(e) Possible variation in (a), (b), (c), and (d) with time. 



A sampling program will depend on the intended purpose of the samples, the 

 time and money available for sampling, and an inspection of the site to be 

 sampled. A brief inspection will often identify the principal variations in 

 the sediment and suggest the best ways to sample these variations. Sampling 

 programs usually involve beach and nearshore sands and potential borrow 

 sources. 



The extent of sampling depends on the importance of littoral materials as 

 related to the total engineering problem. The sampling program should 

 specify: 



(a) Horizontal location of sample. 



(b) Spacing betveen samples. 



(c) Volume of sample. 



(d) Vertical location and type of sampled volume (e.g., surface 

 layer or vertical core). 



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