SCIENTIFIC BACKGROUND 



113 





FAULT LINES OF SEVERAL DIRECTIONS 

 Griffith Park Road. Summit Pass 



nature. Adjectives fail to express their grandeur 

 and significance. Even photography and sketching are 

 insufficient to give adequate concepts of them. 



INTERIOR FAULTS 



There are also many faults that do not make the 

 borders of the physiographic units and are not neces- 

 sarily conspicuous in the topography. There usually 

 occur in the interior areas of the physiographic units, 

 and in general are far less observable than are the mas- 

 ter faults. Sometimes the summit regions are subdi- 

 vided into subordinate ranges and valleys by these 

 secondary fault lines. This is notably true in the in- 

 stances of parts of the summits of the San Gabriel, 

 the San Bernardino and Peninsula Highlands and of 

 the Ferris Plain regions. In instances the lower high- 

 lands are striped into more or less rectilinear linea- 



