180 SOUTHERN CALIFORNIA GEOLOGY 



Burbank and Glendale, and gives character to the 

 beautiful scenic aspect of the south side of the moun- 

 tain. Its northwest continuation may bend around 

 into a structure of the flexured Ventura Ranges. This 

 is apparently a zone of step-faulting, as is indicated in 

 the profiles of the mountain salients and the steep 

 slope from the foot of the mountain towards the north 

 side of the Santa Monica Range. The continuity of 

 the fault to the southeast is to be determined. 



THE PUENTE (WHITTIER) FAULT ZONE 



This is a strongly defined master fault zone orig- 

 inally described by Eldridge and Arnold' and later by 

 English,- which extends from east of the pass of the 

 Santa Ana River at the north end of the Santa Ana 

 Mountains, northwesterly close to La Habra, Brea and 

 Whittier, and after a short stretch of concealment into 

 Griffith Park at the northwest corner of the Santa 

 Monica Range in Los Angeles. It follows the south- 

 west boundary of the Puente Hills near their southern 

 contact with the north side of the Downey Valley Plain, 

 and probably also that of the Repetto Hills of East 

 Los Angeles, although in places its continuity is indefi- 

 nite, discontinuous or concealed. The direction of the 

 Puente Fault is about north 65° west, parallel to the 

 course of the Valyermo section of the Southern Seg- 

 ment of the San Andreas Rift previously described. 

 According to English, many different aspects of throw 

 occur along the line. These suggest rotational move- 

 ments. 



'U. S. Geolog-ical Survey Bulletin No. 309. Washinston, 1907. 

 =U. S. Geological Survey Bulletin No. 768, Washington, 1925. 



