8o 



Sierra Club Bulletin 



mass of the rocks decompose, are set free and fall in minute 

 avalanches, and gradually accumulate until they come to form 

 belts of crystalline soil. In some instances, the various crys- 

 tals occur only here and there, sprinkled in the gray gravel like 

 daisies in a sod; but in others, half or more of the encircling 

 talus seems to be made up of crystals, tilted at all angles, and 

 laid open to the sun. And whether in the mild flush of morn- 

 ing or evening, or in the dazzling white of high noon, they 

 manifest themselves as the most exquisitely beautiful of all the 

 soil-beds in the range. 



In the hollows and levels we find soil-beds that have been 

 compounded and laid down by streams of water. But these 

 may be regarded as little more than reformations of glacial 

 deposits; for the quantity of soil material eroded from solid 

 rock by post-glacial agents is as yet hardly appreciable. Water- 

 beds present a wide range of variability both in size and struc- 

 ture. Some of the smallest, each sustaining a tuft or two of 

 grass, have scarcely a larger area than the flower-plats of gar- 

 dens ; while others are miles in extent, and support luxuriant 

 groves of pine trees two hundred feet in height. Some are 

 composed of mud and sand-grains, others of ponderous boul- 

 ders, according to the power of the depositing current and the 

 character of the material that chanced to lie in its way. 



Glaciers are admirably calculated for the general distribution 

 of soils in consequence of their rigidity and independence of 

 minor inequalities of surface. Streams of water, on the con- 

 trary, are fitted only for special work. Glaciers give soil to 

 high and low places almost alike ; water-currents are dispens- 

 ers of special blessings, constantly tending to make the ridges 

 poorer and the valleys richer. Glaciers mingle all kinds of 

 materials together, mud particles and rock blocks a hundred 

 feet in diameter ; water, whether in oozing currents or passion- 

 ate torrents, constantly discriminates both with regard to size 

 and shape of material, and acts as a series of sieves for its 

 separation and transportation. 



Glacial mud is the finest mountain meal ground for any pur- 

 pose, and its transportation into the still water of lakes, where 

 it is deposited in layers of clay, was the first work that the 

 young post-glacial streams of the Sierra were called upon to 



