304 E. C. ANDREWS. 



mention may be made of the domes, the moraines, and the 

 readjustment of channel grades. 



(a') Channel-grade readjustment. — After the modification 

 of the preglacial Yosemite canon by an ice stream a period 

 of weaker glaciation ensued. Moraines were deposited 

 below El Capitan, and these tended to fill the basin formed 

 by earlier recessional erosion. Then came the present ice 

 drought period, during which the diminished glaciers have 

 practically assumed the inefficient stage of crystalline 

 solids in the Oalifornian Sierras. 



The precipitation which formerly went to the alimenta- 

 tion of glaciers now goes off as water, and in readjusting 

 the old ice flood grade to its own strength the water stream 

 has filled the Yosemite Lake basin almost entirely, burying 

 the moraines in the process. 



(b') Moraines. — A particularly fine group of moraines 

 occurs along the trail from the Tuolumne Meadows to 

 Yosemite by way of the little Yosemite. Under Clouds' 

 Rest they lie above the 8,000 feet level, while under the 

 Half Dome they occur about the 7,000 feet level. The 

 moraines lie in an old cutting curve of the Merced glacier 

 during a glacial flood, the form of the cutting curve being 

 very decided. Upon the decrease in volume of the ice this 

 old cutting curve became at once a " glacial slack," and 

 moraines were dumped on the outer edges of the curve as 

 the measure of lateral strength for the glacier diminished. 

 Thus with continued decrease of ice volume, the cutting 

 curve was filled by lateral moraines which paralleled each 

 other aud crowded towards the Little Yosemite canon. 

 At the same time the old steep cliffs of Clouds' Rest and 

 the Half Dome on the Little Yosemite side became smoothed 

 down to steep dome shapes. 



(c) Domes. — As a general rule, dome shaped masses of 

 rock in the Yosemite present a steep face to the profound 



