The Valley of the South 261 



sandstone, shale, and clay have been uplifted and form the Red- 

 lands Heights and Smiley Heights mesas. Southward the Perris 

 Plain is but thinly veneered with Fernando clays and sands, and 

 weathered knobs of the granite bed-rock project as rugged 

 wind-eroded boulders and crags. 



San Bernardino Range Uplifted 



Finally, as a climax of the great disturbances which have so 

 markedly determined the present character of the landscape, 

 movement again occurred along the many faults along which 

 disturbance had occurred during the preceding periods. The 

 San Bernardino Mountains were at this time raised to their pres- 

 ent height. The earlier deposited alluvial wash was uplifted 

 into the sloping mesas of Smiley Heights and Redlands Heights, 

 and the coarse boulder beds south of San Timoteo Canyon were 

 uplifted so that they now dip markedly toward the north. The 

 San Bernardino Valley subsided still lower than before. Stream 

 activity was renewed and deep canyons were cut. Fans were 

 built at the mouths of streams. The great alluvial mantle, 

 spoken of as "valley fill," which makes up the present surface 

 of the San Bernardino Valley, was deposited, and forms the 

 broad expanses of fertile lands for which the great Valley of 

 Southern California is noted. 



The Fernando epoch is regarded as marking the end of Ter- 

 tiary and the beginning of Quaternary time. The Fernando 

 epoch was marked by disturbances, with great crumpling and 

 folding of the rocks, and vast crushing along the lines of faults. 

 The deposits made by streams since the close of the Fernando 

 epoch are in horizontal position as deposited, or in gently slop- 

 ing layers where thrown down by streams in alluvial cones or 

 fans. The Quaternary deposits, which are widespread through- 

 out the valley from the Badlands on the east westward to the 

 narrowing of the valley northwest, of Pomona, and beyond in 

 the San Gabriel Valley to and including the depressed faulted 

 valley of La Canada, constitute the later alluvium or "valley 



