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University of California Publications in Geology [Vol. 13 



to a saddle and can by no means be considered a cirque. Dollar Lake 

 is retained by a moraine of parabolic contour, the lake itself being at 

 the focus. One limb of the parabola extends up the canon and the 

 other is cut off by the precipitous south side of the canon. This wall 

 is very uneven and somewhat resembles the ice-plucked walls of the 

 cirques, but, being of schist, this action cannot be so clearly recognized. 

 Below the parabolic morainal dam and parallel to it are several other 

 ridges of debris. Farther down they extend across the canon and are 

 fully 300 feet in height. These ridges are due to glaciation, and indi- 

 cate a tendency for the ice to hug the south side of the canon. The 

 ice did not retreat directly up the canon, but to the south side as well. 

 This was probably due to ablation caused by the sun's rays striking 

 the north side of the canon. 



A large amount of water is retained by the glacial till and numer- 

 out large springs flow from the slopes of the moraine. These springs 

 carry out considerable quantities of debris which form mounds. Many 

 springs were seen where no water is now flowing and during the 

 writers short stay a new spring broke forth. This temporary nature 

 of the springs can probably be accounted for by the extremely irreg- 

 ular arrangement of the debris, which must result in correspondingly 

 irregular, and in many cases local, reservoirs. The streams from these 

 springs water a long series of meadows in South Fork and farther 

 down they unite to form a single large stream. 



The most ideal example of glaciation is found at the head of Hatha- 

 way Creek. The writer can best quote Fairbanks and Carey. 4 



It was a long narrow tongue of ice which reached downward a mile and left 

 the most perfect moraines seen. Five semicircular terminal moraines cross the 

 canyon and upon its eastern side is an ideally perfect marginal moraine. The 

 middle one of the terminal moraines is formed of immense blocks of rock and 

 looked at from below its curving front forms a great wall nearly 100 feet high. 

 The lowest moraine, 1000 feet farther down the canyon, is formed of the finest 

 material of any, as though when the first ice tongue came down it found the 

 surface soft and deeply disintegrated. The phenomena here indicate that glaci- 

 ation was of considerable duration, and that the history of the period was any- 

 thing but simple None of these glaciers appears to have descended much 



below 8500 feet, and it will be seen from the descriptions given that the condi- 

 tions had to be just right for their appearance at all. Such conditions were a 

 northward or northeastward facing alcove which headed sufficiently close to the 

 crest to receive the snows which drifted over its summit. 



* Fairbanks, H. W., and Carey, E. P., op. cit., p. 33. 



