18 



fracture zone and are known in the vicinity of Ballona Creek. 

 From east to west they are: the Inglewood, Overland, and 

 Charnock faults. The latter two have only been identified 

 below the land surface, largely on the characteristics of 

 the ground water table. In each case, the western side of 

 the rift has been uplifted relative to the eastern block. 

 Poland, et^ al . , (1948) points out that the transverse profiles 

 across Ballona Creek show that the gravels and sands within 

 the old stream channel dip to the south and frequently are more 

 than 40 feet thicker on the southern side of the channel. This 

 could indicate that a fault partly controls the stream channel, 

 and may also account for the relatively steep and straight 

 bluffs along the Ballona Creek escarpment. The circulation of 

 ground water does not indicate one way or the other whether 

 an east-west fault exists. However, as an alternative to 

 faulting, it is suggested that the stream migrated to the 

 south and as a consequence cut a deeper channel in this direc- 

 tion. 



El Segundo Sand Hills 



From the Ballona Creek outlet to Malaga Cove, a distance 



of 11.7 miles, there are extensive coastal sand dunes which 

 have been termed the El Segundo Sand Hills (Poland, ejt al. , 

 1945). Merriam (1949) made a comprehensive study of the 

 structure, composition, and geologic history of the sand dunes. 

 She notes that the main part of the sand dunes ranges from 

 2.0 miles to 4.2 miles in width, while the active dunes, which 

 lie atop the main ridge, have an average width of 0.4 mile 



