18 SOUTHERN CALIFORNIA GEOLOGY 



on the east side of the same, and also where the move- 

 ment of Gaviota Peak in the Santa Ynez mountains 

 of twenty-four feet in thirty years has been erron- 

 eously reported to have occurred. No measurable 

 present-day movements have been recorded from sur- 

 veys along the southeastern continuation of the line 

 through Southern California, nor have any present-day 

 horizontal movements been witnessed there, although 

 the geologic testimony is to the effect that they have 

 occurred, as is elsewhere herein shown. Shocks have 

 been of comparatively little severity along the main 

 San Andreas fault east of its junction with the San 

 Jacinto fault, where the accumulations and the re- 

 leases from strain are many. In fact, the number 

 of seismisms along this particular section are no more 

 numerous than those reported in some other parts of 

 Southern California. 



Instead of having followed the line of the San An- 

 dreas Rift from San Francisco to Yuma, as has been 

 alleged, the greatest seismicity of the Pacific side of 

 California seems to have been largely localized along 

 stretches of three widely different fault lines, to-wit: 

 the northern stretch of the San Andreas Rift, along 

 which the San Francisco and Tejon earthquakes took 

 place; the western end, or Santa Ynez portion of a 

 fault along the north side of the Transverse Fault Belt, 

 to which the Santa Barbara quake of 1924 and the 

 recent Lompoc quake of November 5, 1927, were re- 

 lated; and the San Jacinto Fault, along which the San 

 Jacinto quakes of 1918 and the Imperial Valley shakes 

 of that and other years have been correlated. 



Comparatively great shocks have also taken place 

 along the Yuma extension of the San Andreas Rift into 



