TITLES AND ABSTRACTS OF PAPERS 135 



glacial retreat. A study of the topography and surface geology of the country 

 at the alleged heads of the "local glaciers," including the slopes of Mount 

 Mansfield and Camels Hump, where, if anywhere, local glaciers might be ex- 

 pected to have left their records, brings to light not only an entire absence of 

 cirques and trough valleys, but the presence in their place of graded mountain 

 sides and typical torrent-worn valleys, and also of deposits of temporary lakes 

 which must have been held in by the continental ice-sheet as it retired toward 

 the north. 



The conclusion is drawn that local snowfields and glaciers did not exist in 

 the Green Mountains at the close of the last Glacial epoch. 



Presented in abstract from notes. 



DrsciTssioN" 



Prof. G. Frederick Wright : In the ablation of a glacial ice-sheet the moun- 

 tain tops will first appear as nunataks. Whether they will support independ- 

 ent glaciers will depend on their height, the amount of snowfall, but chiefly on 

 the extent of surface to retain the snow. The Green Mountains form a much 

 narrower range than the Catskills and have only isolated peaks reaching the 

 same heights ; hence were not so likely to support glaciers. It is evident that 

 the Champlain Valley, between the Greeii Mountains and the Adirondacks, 

 remained full of glacial ice long after the mountain tops on either side were 

 exposed, and that, as the ice diminished, there were extensive terraces formed 

 on the mountain sides at different levels by streams held at those levels by the 

 ice on one side. In many cases these might be mistaken for moraines. 



I*rof. George D. Hubbard raised the question if Doctor Goldthwait was 

 familiar with the eastern side of the Green Mountain Range as shown on the 

 Wilmington sheet, United States Geological Survey Topographic Atlas. Pro- 

 fessor Hubbard presented a statement of strong development of moraines, 

 eskers, and kames in the valleys and around the mouths of mountain valleys, 

 at the head of some of which are cirques — in one cirque three moraine loops 

 and behind each of two a lake. Moraines seem to be definitely related to the 

 valleys heading up on the mountain slopes and have not been in the least dis- 

 turbed by any later glaciatiou. The ice could not have spilled over the moun- 

 tains and come down these valleys. It might possibly have come through a 

 high notch from the Wardsboro Valley north ; but that source could not have 

 supplied ice-tongues to build moraines so closely related to the valleys heading 

 on the eastern face of mountains to the west. A map of the moraines and 

 associated features was shown. 



Prof. John L. Rich : It has impressed me that the speaker is expecting to 

 find evidences of more ui;n-ked erosion and cirque-sculpturing by local glaciers 

 than they are likely, in most places, to have produced. If the local glaciers 

 were lingering remnants of the continental ice-sheet, it seems likely that many 

 of them may have occupied the valleys too short a time to have produced the 

 marked erosional effects — truncated spurs and strongly cut cirques — mentioned 

 by the speaker. 



X— p.ii.L. (iF.oL. Soc, Am., Vol. 28, 10](i 



