126 



a general seaward decrease in texture exists, but it is modified 

 by (1) the presence of sediments deposited in the geologic past, 

 and (2) submarine topography which in part causes deviations in 

 the sediment distribution. 



Probably most of the clay and a large portion of the silt 

 originating within the distributary drainage area is carried 

 beyond the shelf and deposited in the offshore basins. It is 

 likely that bottom scavengers break up sediments into smaller 

 particles, but there are no quantitative data on this process. 

 It is probable, however, that beach sand does not become 

 appreciably broken down by transport along the coast by littoral 

 drifting (Mason, 1942). 



Since littoral drift along most of the shore is southeast- 

 ward, and meets northward drifting sand at Redondo, some of the 

 sand must go seaward - presumably out through Redondo Canyon, 

 After the construction of Redondo breakwater, much of the south- 

 ward drifting sand was trapped by this structure. Prior to the 

 construction of the breakwater, however, a large amount of sand 

 may have been lost through the canyon. According to Mr, William 

 Herron, Army Corps of Engineers (oral communication), a con- 

 siderable quantity of sand is lost seaward between Santa Monica 

 and Redondo, and at the present time it is possibly as much as 

 150,000 cubic yards per year. 



Although sediments may accumulate on slopes and later slide 

 off into deep water, this does not seriously effect calculations 

 on the rate of sedimentation on the shelf. More important, how- 

 ever, is the amount of sediments deposited and later resuspended 

 and carried in a seaward direction. The more or less continuous 



