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Sierra Club Bulletin 



its internal structure. The position of each valley upon the Yo- 

 semitic zone indicates a marked and inseparable relation to the 

 ancient glaciers, which, when fully deciphered, amounts to cause 

 and effect. So constant and obvious is this connection between 

 the various Yosemites and the neve amphitheatres which foun- 

 tained the ancient ice-rivers, that an observer, inexperienced in 

 these phenomena, might easily anticipate the position and size of 

 any Yosemite by a study of the glacial fountains above it, or the 

 position and size of the fountains by a study of their comple- 

 mentary Yosemite. All Yosemites occur at the junction of two 

 or more glacial canons. Thus the greater and lesser Yosemites 

 of the Merced, Hetch Hetchy, and those of the upper Tuolum- 

 ne, those of Kings River, and the San Joaquin, all occur imme- 

 diately below the confluences of their ancient glaciers. If, in fol- 

 lowing down the canon channel of the Merced Glacier, from 

 its origin in the neve amphitheatres of the Lyell group, we 

 should find that its sudden expansion and deepening at Yosemite 

 occurs without a corresponding union of glacial tributary cafi- 

 ons, and without any similar expansion elsewhere, then we 

 might well be driven to the doctrine of special marvels. But this 

 emphatic deepening and widening becomes harmonious when 

 we observe smaller Yosemites occurring at intervals all the way 

 down, across the Yosemitic zone, wherever a tributary canon 

 unites zvith the trunk, until, on reaching Yosemite, where the 

 enlargement is greatest, we find the number of confluent glacier- 

 canons is also greatest, as may be observed by reference to 

 Fig. I. Still further, the aggregate areas of their cross-sections 

 is approximately equal to the area of the cross-sections of the 

 several resulting Yosemites, just as the cross-section of a tree 

 trunk is about equal to the sum of the sections of its branches. 

 Furthermore, the trend of Yosemite valleys is always a direct 

 resultant of the sizes, directions, and declivities of their conflu- 

 ent canons, modified by peculiarities of structure in their rocks. 

 Now, all the canons mentioned above are the abandoned chan- 

 nels of glaciers; therefore, these Yosemites and their glaciers 

 are inseparably related. Instead of being local in character, or 

 formed by obscure and lawless forces, these valleys are the only 

 great sculpture phenomena whose existence and exact positions 

 we may confidently anticipate. 



