170 SOUTHERN CALIFORNIA GEOLOGY 



While the fault line is chiefly expressed by the sur- 

 face contours, there are instances of exposed contacts, 

 as in the road-cutting on the Associated Oil Company's 

 ground on Inglewood Hill and in the old sand pits on 

 the south side of Signal Hill at Long Beach. This 

 faulting is due to stresses along the line of the folding 

 of the Dominguez Range. Some of the small shocks 

 which Los Angeles feels now and then are derived 

 from this line of faulting. 



FAULTED STRUCTURES OF THE SUBMERGED 



BENCH 



The contour map of the submerged border-land of 

 Southern California (which is, perhaps incorrectly but 

 for the want of a better name, termed "the Continental 

 Shelf" upon our map, Plate I) somewhat strongly 

 suggests the existence there of several alternations of 

 uplifted and down-thrown ribbons of faulted structures 

 of the northwest trending types. These we have desig- 

 nated upon the map as the Catalina, San Clemente, 

 San Nicolas and Submerged Ranges, and Troughs No. 

 1, 2, 3 and 4, respectively. The graben-like character 

 of trough No. 2, between the Catalina and San Cle- 

 mente Ranges, is very apparent, and has been prev- 

 iously noted and illustrated by Tabor.^ As cited on a 

 previous page I have arbitrarily placed these features 

 in the first group of northwest structures. 



There are strong suggestions of several more or less 

 parallel faults of the northwest-southeast groups, 

 which may cut slightly diagonally across the older 

 north 40 west trends of the submerged bench, as indi- 



^"Fault Troug-hs." Journal of Geology, October-Novembei-, 1927. 



