Drift in Mimteapolis, Minn. — Upham. 281 
winters. They demonstrate that when they were engraved on 
the rock, near the time of departure of the ice-sheet, its drift 
above the locaHties bearing these striae was wholly englacial. 
No drift had there been deposited under the ice to shield the 
rock from continued abrasion, which effaced the older striae of 
earlier movements from the northeast. 
The Glacial Lake Hamline. 
Three years ago, in my examination of the modified drift 
plateaus of St. Paul, high above the river valley drift, they were 
identified as the deposits of a glacial lake, which is named for 
Hamline, in the western part of the St. Paul city area, situated 
on the earliest and largest of these plains and plateaus.* Lake 
Hamline grew to be, in its later and maximum extent, about 
ten miles long and six miles wide, covering more than half the 
area of St. Paul. It was bounded on the east and west by still 
unmelted tracts of the departing ice-sheet, at whose borders 
typical marginal moraines were formed, passing through the 
eastern and western parts of St. Paul, in each case crossing 
the Mississippi river valley. The western one of these mo- 
raines, well developed in St. Anthony Park, also lies partly 
within the east and northeast limits of Minneapolis, having a 
width of one and a half to two miles, including both sides of 
the interurban boundary ; and northward, in the neighborhood 
of the Minneapolis city reservoir, it increases in hight and 
expands to a width of about three miles. 
Knowing that some of the plains of gravel and sand in 
southwestern Minneapolis have as great altitude as the Sum- 
mit Avenue plateau and other late deposits of lake Hamline 
in St. Paul, I conjectured that the glacial lake might have 
reached also across Minneapolis, with the retreat of the ice- 
fields on that side, before their melting on the southeast laid 
open the Mississippi valley below St. Paul, thus draining the 
lake away. It is now ascertained, however, as before noted, 
that the modified drift of Minneapolis shows no dependence on 
lacustrine conditions. It is wholly explainable by fluvial ac- 
tion, while the ice border withdrew. We have no records of 
lake Hamline outside the area inclosed by the east and west 
moraines of St. Paul. When the modified drift in Minneapo- 
*Biilletin G. S. A., vol. viii, pp. 183-196, with map. 
