222 SOUTHERN CALIFO'T^NIA (.EOLOCiY 



epoch may be mentioned, the San Gabriel, Sierra 

 Madre, Verdugo, Puente, Elsinore, San Jacinto, San 

 Andreas, Mill Creek, Newberry, Cadiz and Garlock 

 faults. In fact I believe that there was movement 

 along most of the master faults of Southern California 

 in Pleistocene time. 



That the master faulting which chiefly produced the 

 present day aspects of Southern California took place 

 prior to the Recent epoch is testified by the defacing 

 erosions which the escarpments have suffered since 

 their origin and which must have required considerable 

 lengths of time for their accomplishment. This is 

 also testified by the fact that the extensions of the 

 fault lines across the valley plains are buried and con- 

 cealed beneath the sediments of post-Pleistocene age. 



The outstanding fact of the geological history of 

 Southern California is that the great earth movements 

 whose features outline our present day physiography, 

 took place in various epochs of the Pleistocene. This 

 was the time of the Great Glacial Epochs in North 

 America and Europe ; of the "forgotten age" of man- 

 kind, whose myths which have been handed down to 

 us, tell of the prehistoric "earth dividings," "polar 

 changes," "disappearing continents" and human dis- 

 persals — all of which tradition allfirms and which 

 science may some day explain. 



The following specific instances of movement along 

 these fault lines in the Pleistocene Age may be men- 

 tioned : 



1. The marine Pliocene strata of the Colorado De- 

 pression which originally were deposited below sea level 

 have been uplifted 1,000 or more feet by a movement 

 along the easterly Mill Creek fault at its north end, 



