BY PROF. DAVID, RICHARD HELMS, AND B. F. PITTMAN. 35 



There must have been a long pause of the glacier snout at the 

 present position of the lower moraine. 



Subsequently the glacier retreated more or less rapidly up the 

 valley until its front rested upon the present site of Lake May. 

 There was then a second long pause during which the second 

 terminal moraine embankment, about one-quarter of a mile long and 

 75 feet in greatest thickness, was slowly built up. Then came a 

 second retreat of the glacier up the valley, perhaps more gradual 

 than the first, and the ice melted back to near Ramshead Pass 

 without leaving any further definite terminal moraine embank- 

 ment, although its retreat is marked by deposition of a certain 

 amount of irregularly distributed moraine matter along the 

 bottom of the valley, with a little lateral moraine along its 

 eastern side. 



As regards the thickness of the ice during the later of these 

 two glaciations, an examination of the smoothed granite surfaces 

 on the west side of this valley shows that the valley must have 

 been glaciated up to a level of at least 150 feet above the present 

 level of Lake May, and as the moraine dam at this lake is about 

 75 feet high, a farther thickness of perhaps that amount might 

 be added for the former depth of the glacier ice at this epoch. 

 The ice, therefore, in this valley was probably at this time at 

 least 200 feet in thickness. 



During the earlier phase of this valley glaciation, when the 

 lower terminal moraine was formed, as the moraine is now 95 feet 

 high and was formerly at least 120 feet high, possibly 180 feet, 

 the ice at this terminal moraine must at one time have been 

 probably from 150 to 200 feet thick, and higher up the valley 

 cannot have been much less than 300 feet thick. A cursory 

 examination of the rocks for a short distance below the level of 

 this older terminal moraine showed that they were more or less 

 smoothed, apparently by ice, for some distance down the valley. 

 Definite evidence, however, of ice action was not observed below 

 the low^er moraine dam, but it would be premature, in the 

 absence of detailed examination, to conclude that no glacial 

 evidences exist at a lower altitude. 



