66 NEW YORK STATE MUSEUM 



at once that during the time of maximum subsidence the region 

 stood several hundred feet lower than now, and that the most 

 recent land movement has been one of elevation which has brought 

 the marine deposits to their present position several hundred feet 

 above sea level. This last (upward) movement has a direct bear- 

 ing upon the glacial lake deposits of the North Creek quadrangle, 

 and it is important to note that this upward movement was dif- 

 ferential with greatest uplift toward the north. Using the figures 

 of Professor Woodworth, the greater uplift of the land toward 

 the north, passing along the southern part of the Champlain val- 

 ley, has amounted to about 3^ feet a mile.^ Practically this same 

 figure may be applied to the North Creek area since it is so close to 

 the southern end of the Champlain valley. 



DIRECTION OF ICE FLOW 



The evidence is conclusive that the North Creek quadrangle was 

 vigorously glaciated. Many widely distributed glacial striae — 

 sixty in all — have been observed within the map limits and are 

 all recorded on the geologic map. Such a large number of striae 

 is very unusual, certainly being far greater than for any other 

 quadrangle so far mapped in the eastern, central, or southern Ad- 

 irondacks. As usual the striae are most frequently seen along the 

 highways in the valleys and on ledges from which the glacial drift 

 covering has recently been removed. A number of striae have 

 been found away from the roads and even on mountain sides, but 

 never on mountain tops because where exposed on the bare ledges 

 they have been obliterated by postglacial weathering. 



Of the sixty recorded striae, the extreme range in direction is 

 only from south 20° east to south 20° west, with the north-south 

 direction nearly an average. In fact many of the striae do run 

 north-south and very few vary more than 10° either side of this. 

 The direction of ice movement indicated by these striae is excep- 

 tional for the central and eastern Adirondacks as judged by obser- 

 vations made on the Long lake, Paradox lake, and Elizabethtown- 

 Port Henry sheets over which areas the general movement was 

 southwestward at the time of maximum glaciation. The reason 

 for the southward movement over the North Creek sheet is not 

 an easy thing to account for, though it may possibly have been due 

 to a crowding of the ice into the Hudson valley and a local deflec- 

 tion of the general southwesterly current where the ice flowed 



1 N. Y. State Mus. Bui. 84, p. 206, 228 and plate 28. 



