178 SOUTHERN CALIFORNIA GEOLOGY 



the Whittier Fault by English on the south. Besides 

 these there may be many secondary or interior faults 

 within the belt, the details of which have not as yet 

 been determined. 



The nature of the San Andreas Fault line has already 

 been described. A word or two must be given concern- 

 ing some of the other rifts which compose the belt. 



THE SIERRA MADRE AND SAN GABRIEL 

 FAULT LINES 

 Two conspicuous fault lines are found adjacent to 

 the southwest side of the San Gabriel Highland and 

 have been mapped and described by Kew as the San 

 Gabriel and Sierra Madre Rifts. The northernmost of 

 these is the San Gabriel Rift and it lies within the 

 summit area of the San Gabriel Highland block, about 

 four miles from its southwest border. It extends 

 northwesterly from near the town of Sierra Madre 



SAN GABRIEL SCARP AND TERRACES OF ELEVATION 

 MOUTH OF TUJUNGA CREEK 



