156 SOUTHERN CALIFORNIA GEOLOGY 



CRATER AND LAVA FLOW NEAR AMBOY 



themselves. The topography indicates that this 

 fault line, about which no more is known or has been 

 given than is stated here, is a zone of step-down faults 

 descending to the great Amboy Trough. 



The western end of this northwesterly fault appar- 

 ently ceases at the Garlock fault thirty miles south- 

 east of Trona. No attempts have been made to ascer- 

 tain the details of its extent southeastward into Ari- 

 zona and Mexico. 



The line of the Cadiz fault extends southeastward 

 from the angle of the Sierra Nevada near Inyokern 

 to the Colorado River just south of Riverside Moun- 

 tain. 



Between the line above mentioned and the great 

 Pinto Mountain east-west fault there is a wedge-like 

 triangular area of desert country that narrows to the 

 east from the Antelope Valley embayment of the Mo- 



