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The movement of sand along the central bayshore has been 

 the subject of several investigations in past years. As a 

 result of these studies, it seems probable that the bay acts 

 as a trap for most of the entering sedimentary material coarser 

 than fine silt and clay. Such a conclusion indicates a negli- 

 gible transport around Palos Verdes Hills coast. This is 

 likely true because of (1) the probability that most of the 

 sediments carried to the south by littoral currents are trapped 

 by the Redondo breakwater or are carried into Santa Monica-San 

 Pedro Basin through the canyon; (2) observations by the U. S. 

 Army, Corps of Engineers (1955) indicate that there is a pre- 

 dominant downcoast drift of sediment to Redondo, and a net up- 

 coast drift between Clifton and Rocky Point; (3) Johnson (1940) 

 noted that between 1939 and 1940,370,000 cubic yards of sediment 

 accumulated on the south side of the Redondo breakwater, but 

 very little on the north side. He postulated a southeast source 

 for the sand drift. It may also be, however, that conditions 

 are such that the sand is by-passed around the breakwater and 

 deposited on the southern side, thus originating from the north; 

 (4) bottom samples close to shore around the Palos Verdes coast 

 indicates rocky bottom and little or no sediment cover. Only 

 small pocket beaches of locally derived composition occur along 

 this rugged section of the coast. Most of the shore consists 

 of rock platforms and cobble beaches; (5) wave refraction dia- 

 grams in the southern part of Santa Monica Bay show that a 

 northward drift near Rocky Point would be accomplished with 

 greater ease than a southeast drift around the Palos Verdes 

 Hills; and (6) more or less permanent rip currents occur in the 



