610 GEOLOGY OF OLD HAMPSHIRE GOUNTY, MASS. 



oscillations overriding beds already deposited, and that it "calved" and sent 

 icebergs down the valley, will appear in the description of the valley beds 

 here given. Because of the peculiar configuration of the valley, this is 

 most plainly discernible in the Hadley basin, less so in the Springfield 

 basin to the south, and in the Montague basin, though in the last it can 

 be clearly proved. 



One must recall briefly the shape of the Connecticut Valle}", as already 

 defined (p. 9), while occupied by the Triassic sandstones, and as now reoc- 

 cupied bv the Connecticut lakes. The eastern rocky blufl' runs south one 

 point west from Xorthfield to Mount Toby, turns on this and runs south- 

 west by south, but more irregularly, to the Belchertowu Ponds at the east 

 end of Mount Holyoke, and then south to the south line of the State. 



The western line runs from near the river in Vernon south through 

 West Northfield, turns west across Bernardstou and along the north line of 

 Greenfield to its northwest corner, where, near the mouth of Leyden Glen, 

 Mrs. Williams was killed by the Indians in 1718. It turns southward again 

 along the west border of the town. Greenfield was laid out so as to include 

 all the flat country, and the barren hills were left for Shelburne and 

 Leyden. The line goes south to Elizabeth Rock, in NorthamiDton, at the 

 apex of the "big bend" of the Connecticut. Here it is set back west 

 again, as before, to include Northampton, and goes on one point west of 

 south to the south line of the State in Southwick. 



The r-shaped Holyoke range cut off the Springfield basin, and the 

 L-shaped Deerfeld-Toby range cut off the Montague basin on the south 

 and north, respectively, from the Hadley basin. So that, south of the 

 Holyoke range, the area was greatlj^ sheltered from the ice so soon as it 

 sank below the crest of the range, and the ice in the Hadley basin was 

 projected into the southern continuation of the latter along the western foot 

 of this range, as the southwesterly strife there indicate. 



On the other hand, a separate lobe of the ice occupied the main valley 

 of the Connecticut in the Montague basin, and another lobe occupied the 

 northwestern lateral extension of the Hadley basin in Deerfield and Green- 

 field, the latter lingering longest in Greenfield — indeed, till after the maxi- 

 nmm of the flood had passed. 



The waters occupied the basin while it was still largely encumbered 

 with the remnants of the glacial ice, and during all the time of the deposition 

 of the central clays floating ice was abundant. The occurrence of arctic 



