140 OUR NATIONAL PARKS 



while others beginning to give way to the wea- 

 ther are thinly sprinkled with coarse angular 

 gravel. Some of them are full of crystals/ which 

 as the surface of the rock is decomposed are set 

 free, covering the summits and rolling down the 

 sides in minute avalanches, giving rise to zones 

 and beds of crystalline soil. In some instances 

 the various crystals occur only here and there, 

 sprinkled in the gray gravel like daisies in a 

 sod ; but in others half or more is made up of 

 crystals, and the glow of the imbedded or loosely 

 strewn gems and their colored gleams and glint- 

 ings at different times of the day when the sun 

 is shining might well exhilarate the flowers that 

 grow among them, and console them for being 

 so completely outshone. 



These radiant sheets and belts and dome-en- 

 circling rings of crystals are the most beautiful 

 of all the Sierra soil-beds, while the huge taluses 

 ranged along the walls of the great canons are 

 the deepest and roughest. Instead of being 

 slowly weathered and accumulated from the 

 cliffs overhead like common taluses, they were 

 all formed suddenly and simultaneously by an 

 earthquake that occurred at least three centuries 

 ago. Though thus hurled into existence at a 

 single effort, they are the least changeable and 

 destructible of all the soil formations in the 

 range. Excepting those which were launched 

 directly into the channels of rivers, scarcely one 



