C. H. HITCHCOCK THE CONNECTICUT VALLEY GLACIER. 7 



glacier may, if of continental type and of sufficient thickness, assume a fairly uni- 

 form general slope and a moderately definite direction of general movement, trie 

 prevailing movement, particularly in the lower portions of the sheet, may be purely 

 local and determined by the local slopes. This predominance of local over general 

 movement is magnificently illustrated along the lower reaches of Frazer river in 

 British Columbia, where the lesser mountains, up to three or four thousand feet 

 in altitude, are converted into huge tors; but while the prevailing trend of the 

 great flutings in which the direction of flow is recorded is toward the coast, the 

 trend is by no means uniform, and many flutings indicate prevailing movement 

 down the slopes, such as might be expected in a slowly settling neve. Now in such 

 regions as British Columbia and the Swiss Alps, this local downward impulse must 

 so far preponderate as to keep the valleys filled, howsoever rapidly ablation may 

 progress, leaving the divides to be first laid bare. On the other hand, there is 

 good reason for believing that in the plains of the upper Mississippi valley the ice 

 pushed forward under a general impulse which so far preponderated over the local 

 impulse down the gentle slopes that when ablation commenced, superglacial streams 

 were formed and gradually cut through the ice and into the subterrain, so that the 

 entire surface became diversified by a drainage corresponding in many respects to 

 that of to-day — in short, in northeastern Iowa at least, this superglacial drainage 

 was superimposed upon the land surface and remains to-day a record of the sur- 

 face configuration of the continental glacier. These types of glacial action must 

 be carefully distinguished; but there is perhaps a question as to which type was 

 represented by the ice-work of New England. 



Profess* >r ( Jlaypole drew illustrations from Alpine glaciers. He thought 

 the Connecticut valley glacier more comparable to Alpine valley glaciers, 

 and particularly to the lower part of the Mer de glace. 



Mr Gilbert regarded the possibility of upper ice moving over inferior 

 ice as demonstrated. He had observed phenomena which nothing else 

 could explain. In the " finger lakes " of New York each valley has been 

 shaped by undercurrents in the ice, while the region lias been planed 

 differently. 



Professor Hitchcock regarded the Connecticut valley glacier as a local 

 glacier from the White mountains toward the close of the glacial episode. 



Professor John C. Branner read the next paper : 



THE OZARKS AND THE GEOLOGICAL HISTORY OF THE MISSOURI PALEOZOIC 



BY G. C. BROADHEAD 



Remarks were made by J. J. Stevenson and H. S. Williams. 

 The Society then adjourned until the following day. 



