150 SOUTHERN CALIFORNIA GEOLOGY 



location and description of this feature, originally de- 

 scribed by Hess, have recently been more fully set 

 forth in a paper by Dr. Noble. ^ 



This fault extends in a northeast direction from 

 the San Andreas Rift east of Tejon Pass into 

 Utah along the boundary between the southeast side 

 of the Tehachapi Highland and the northwest side 

 of the great Mojave Desert. Many short, parallel 

 northeasterly grooves suggestive of northeast fault 

 lines are found in the San Gabriel, Puente and Repetto 

 Ranges and in the west side of the San Jacinto High- 

 lands. 



Suggestions of northeast-southwest extending 

 faults through some of the larger mountain passes 

 are also found. A very long and strong fault of this 

 kind probably passes from the Saboda Hot Springs 

 northeastward through the San Jacinto Mountain be- 

 neath the alluvial formations of the east end of the 

 San Gorgonio Pass, and through the Morongo Valley. 

 Parallel faults of this direction also appear in the 

 physiography of the northwest side of the San Jacinto 

 Mountains and the Morongo Valley. 



There is also some evidence that structure lines of 

 a northeast trend — either folds or faults — may occur 

 beneath the surfaces of the Foothill and Downey Valley 

 Plains, as buried continuations of the saddles between 

 the individual domical hills of the bordering Puente, 

 Montebello and Dominguez Ranges. 



The northeast trends are sometimes expressed by 

 foldings. The Los Angeles, San Gabriel and Santa 



'Noble, L. F. "The San Andreas Rift and Other Desert Activity in the 

 Desert Region of Southeastern California." Carneprie Institution Year Book 

 25, Washington, 1927, called attention to the resemblances between thij fault 

 and the San Andreas Rift. 



