GLACIAL AND POST-GLACIAL HISTORY 627 



to the Hudson-Champlain water body, nor even to the Higher Glacial 

 Lake Champlain water body, but were made after the abandonment 

 of the Fort Edward outlet. In 1903 Mr. Upham referred the low- 

 level delta of the Hudson at Fort Edward and certain high-level 

 terraces in Chesterfield in the Champlain region to Lake St. Lawrence. 

 As will be seen from the foregoing account of the history of this 

 region, the present writer considers this low-level delta at Fort Edward 

 as having been made either in the latest stage of the Hudson-Cham- 

 plain water body or in the earhest stage of Higher Glacial Lake 

 Champlain, and the high-level terraces in the northern part of the 

 Champlain region as having been made in Higher Glacial Lake 

 Champlain. If the non-fossiliferous levels in the lower series of 

 terraces in the Lake Champlain region be referred to Lake St. Law- 

 rence, the Fort Edward delta and the high-level terraces in the 

 northern Lake Champlain region cannot be so referred. Since it 

 is doubtful if the water body in which either the high-level terraces 

 or the Fort Edward delta were made reached to the St. Lawrence, 

 it would seem to be inappropriate to call it Lake St. Lawrence. 

 Altogether it seems best to reserve this name for the hypothetical 

 lake which followed the union of the water bodies in the Ontario 

 and Lake Champlain regions, as originally deiined by Upham. 



MARINE CHAMPLAIN. 



If the upper terrace of the lower series represents the sea-level, 

 then, on the abandonment of the Fort Edward outlet, the history of 

 the Higher Glacial Lake Champlain was closed and that of Marine 

 Champlain was inaugurated. If during the fall of Higher Glacial 

 Lake Champlain level to the upper terrace of the lower series there 

 was no change in the altitude of the land, then, since the difference 

 in level between the two series is generally 120 feet. Higher Glacial 

 Lake Champlain must have been at its closing stage 120 feet above 

 sea-level, and at its higher stage, barring uplift during its history, 

 it must have been at least 75-100 feet higher. If the upper terrace 

 of the lower series of terraces does not represent the sea-level, but 

 does represent a lake-level, then Higher Glacial Lake Champlain 

 was more than 120 feet A. T. when its outlet was abandoned. It is 

 to be noted that the level of the Fort Edward outlet valley at White- 



