DATE OF CIRQUE-CUTTING IN THE ADIRONDACKS 547 



gentle slope of Great Gulfs southeastern wall is not confined to the higher 

 levels, where alone the impact of southeast-moving ice would be effective, 

 but continues unchanged to the depths of the Gulf, as is expectable if 

 structural features have controlled the slope. It is worthy of note, also, 

 that the east wall of King Ravine and the south wall of Tuckerman's 

 Ravine, both exposed to the supposed impact of southeast-moving ice, 

 have not been "rubbed down,^' but on the contrary are exceptionally sharp 

 and steep. 



It is well known that cirques on the eastern side of a north-south 

 mountain ridge are apt to be more strongly developed than those on the 

 west, since a number of factors favor the better alimentation of glaciers 

 on the eastern side. In the Presidential Range the Ravine of the Cas- 

 cades and the Ravine of the Castles, opening toward the northwest, are 

 on the west side of the main crest, while all the cirques opening toward 

 the southeast are east of the crest. Headward erosion of the latter cirques 

 should be the most effective and produce the steepest headwalls. 



Goldthwaif s belief in the early age of the cirques does not rest alone 

 on the arguments criticized above; hence any complete discussion of his 

 theory must consider other lines of reasoning which I have not had the 

 opportunity of testing in the field. My object has been not to disprove 

 the theory, but to question the validity of certain arguments presented in 

 its support, and so to keep the minds of other students of the region alive 

 to the possibility that the greater part of the cirque-cutting may, after all, 

 have been accomplished after the continental ice had disappeared from 

 the higher peaks. 



Date of Cieque-cutting in the Adirondack Mountains 



In support of this latter interpretation one may appeal with some con- 

 fidence to certain physiographic features in the Adirondack and Catskill 

 Mountains. If local glaciation antedated the coming of the continental 

 ice-sheet in the White Mountains, one should expect the same sequence 

 of events in neighboring mountain regions. If the absence of local mo- 

 raines in the White Mountains is due to their removal by a later advance 

 of the continental ice, such moraines should, for the same reason, be ab- 

 sent in the Adirondacks and Catskills. On the other hand, if undoubted 

 moraines of local glaciers exist in the two mountain groups last named, 

 this fact would cast serious doubt on Goldthwait^s theory of an early date 

 for the local glaciation in the White Mountains. To test this line of 

 reasoning in the field I made brief visits to portions of the Adirondack 

 and Catskill Mountains in the fall of 1916. 



