74 



Sierra Club Bulletin 



delightfully gardened and forested, occur in all deep Yosemitic 

 cafions trending in an east and west direction; but their first 

 forms are so heavily obscured by thousands of years of weath- 

 ering that their shadow-glacial origin would scarcely be sus- 

 pected. 



In addition to these broad zones and fields and regularly de- 

 posited moraine ridges, glacial soil occurs in isolated strips and 

 patches upon the wildest and most unlikely places — aloft on 

 jutting crags, and along narrow horizontal benches ranged one 

 above another, on sheer-fronted precipices, wherever the strong 

 and gentle glaciers could get a boulder to lie. To these inac- 

 cessible soil-beds companies of pines and alp-loving flowers 

 have found their way, and formed themselves into waving 

 fringes and rosettes, whose beauty is strikingly relieved upon 

 the massive ice-sculptured walls. 



Nothing in the history of glacial soil-beds seems more re- 

 markable than their durability in the forms in which they were 

 first laid down. The wild violence of mountain storms would 

 lead one to fancy that every moraine would be swept from pla- 

 teau and ridge in less than a dozen seasons, yet we find those 

 of the upper half of the range scarcely altered by the tear and 

 wear of thousands of years. Those of the lower half are far 

 more ancient, and their material has evidently been shifted and 

 reformed until their original characteristics are almost entirely 

 lost. 



These fresh glacier-formed soils are subject to modifications 

 of various kinds. After the coarse, unbolted moraine soils de- 

 rived from granite, slate, and lava have been well watered and 

 snow-pressed, they are admirably adapted for the ordinary food 

 and anchorage of coniferous trees, but further manipulation is 

 required to fit them for special grove and garden purposes. The 

 first and most general action to which they are subjected is that 

 of slow atmospheric decomposition, which mellows and 

 smooths them for the reception of blooming robes of under- 

 shrubs and grasses, and up to a certain point augments their 

 capacity for the support of pines and firs. Streams of rain and 

 melting snow rank next in importance as modifiers of glacial 

 soils. Powerful torrents waste and change the most compact 

 beds with great rapidity, but the work done by small rain-cur- 



