212 SOUTHERN CALIFORNIA GEOLOGY 



Probably this decline is taking place so slowly that it 

 will hardly be appreciable to our day and generation, 

 but the thought is far more assuring than the imagi- 

 nary, alarming and unfounded conjectures of disaster. 

 INTERESTING EVENTS IN THIS VICINITY 

 DURING THE GLACIAL EPOCHS 



It was during the Pleistocene that most of the great 

 belted trends, highlands, valleys, sea coasts, terraces, 

 islands and other features of the topography that I 

 have described, and that have given to Southern Cali- 

 fornia its charm and lure of today, were made ; that the 

 lands on the opposite sides of the San Andreas Rift 

 are supposed to have had their greatest horizontal 

 drifting past each other; that the high and lowland 

 blocks chiefly moved up and down ; that our older 

 rivers were dismembered or diverted ; that our sea 

 coast line migrated back and forth; that the. beautiful 

 elevated terraces were engraved upon the borders 

 of our islands, coasts and inland mountains ; and that 

 the great transverse buckling of the trends took place. 



It was in Pleistocene time that much of the ma- 

 terials of the stratified rocks were deposited ; that the 

 strata of our ranges of the Dominguez, Ventura and 

 Puente types were folded into their oil-containing 

 arches, and that the alternating valleys were also 

 made and veneered with their wealth-yielding soil. 

 Erosions of the rising highlands, and loadings of the 

 sinking coasts and valleys by sediments were also 

 active. 



Also during this epoch the "Atlantis"-like subsidence 

 of our continental margin took place; the western 

 and southern continuations of the Coast Ranges may 

 have disappeared beneath the Pacific's waters; the 



