GLACIAL AND POST-GLACIAL HISTORY OF THE 

 HUDSON AND CHAMPLAIN VALLEYS. 11.^ 



OVTLINE— Concluded. 

 History. 



Hudson water body and successive positions of ice-edge as it retreated through 



Hudson Valley. 

 Successive positions of the ice-edge in the passages from Hudson to Cham- 

 plain Valley. 

 Successive positions of ice-edge in Champlain Valley. 

 Hudson-Champlain water body. 

 Higher Glacial Lake Champlain. 



Erosion of Fort Edward Valley — making upper series of terraces. 

 Lake St. Lawrence. 

 Marine Champlain. 



Making lower series of terraces. 



Extended course of Poultney-Mettawee River. 

 Inauguration of present Lake Champlain. 



Drowning of lower Poultney-Mettawee River Valley. 



Cutting of outlet of Lake Champlain. 

 History in Hudson Valley in Higher Glacial Lake Champlain time and later. 



Disappearance of Hudson water body. 



Trenching of old lake- or old sea-fioor of Hudson Valley. 



Origin of Hudson Deeps. 



Drowning of lower Hudson. 



Post-Hudson-Champlain changes of drainage in the Hudson^Valley. 



Piracy of Outlet Creek and beheading of Drummond Creek. 

 Correlation of Terraces in the Champlain Valley with those in the Hudson 

 Valley. 



First assumption. 



Second assumption. 



.A.nother ''nterpretation. 

 Altitude of Hudson water body. 

 Origin of Hudson water body. 



Lake hypothesis. 



Sea hypothesis. 



Origin of northward rise of gravel plateaus on each hypothesis for Hud- 

 son water body. 



Origin of submerged channels on each hypothesis for Hudson water 

 body. 

 ^ Continued from p. 469. 



617 



