WISCONSIN GLACIATION 509 



course not far from Little Falls, where primitive men made quartz 

 implements before the upper Mississippi was wholly uncovered from 

 giaciation. 



By its next recessions the ice-border was withdrawn to the eighth, or 

 Fergus Falls, moraine, and the ninth, or Leaf Hills, moraine. These 

 are merged together in the prominent accumulations of the Leaf Hills, 

 which reach in a semicircle from Fergus Falls to the southeast, east, 

 and northeast, a distance of 50 miles, marking the southern limits of 

 this ice-lobe when it terminated nearly due west of Little Falls and 

 halfway between the south and north borders of Minnesota. Conspic- 

 uous moranic hills a few miles east of Little Falls and others in the 

 north part of Morrison County and along its west side seem to be corre- 

 lated with the Fergus Falls moraine. Much of the modified drift of 

 the Mississippi Valley at Little Falls was deposited when the ice-sheet 

 terminated at these hills, 5 to 15 miles distant to the east, north, and 

 west. 



When the tenth, or Itasca, moraine and the eleventh, or Mesabi, 

 moraine were amassed, crossing the lake region at the head of the 

 Mississippi, probably the gravel and sand of the modified drift were 

 entirely deposited north of Little Falls. The twelfth, or Vermilion, 

 moraine, the most northern mapped in Minnesota, skirting the south 

 side of Net, Pelican, and Vermilion lakes, consists of relatively small 

 drift hills and ridges, with very abundant boulders. Thence to the 

 central gathering grounds of the ice^sheet, west, south, and east of Hud- 

 son Bay, doubtless many other moraines were formed by its wavering 

 but mainly receding borders, which await discovery when the glacial 

 drift of those wooded and very scantily inhabited regions shall be fully 

 explored. 



Contemporaneously with the accumulation of the Dovre and later 

 moraines, the Grlacial Lake Agassiz was formed by the retreating Kee- 

 watin ice-barrier in the basin of the Bed Eiver and Lake Winnipeg, with 

 outlet across the continental watershed and along the Minnesota and 

 Mississippi rivers. The earliest and highest Herman beach, much up- 

 lifted above its original level, has now, on the west side of this very 

 large glacial lake, a northward ascent of about 35 feet in the first 75 

 miles north from its mouth, at Lake Traverse, about 60 feet in the 

 second 75 miles, and about 80 feet in the next 74 miles to the inter- 

 national boundary. Farther to the north, in Manitoba, the rate of ascent 

 of the early beaches is increased to two feet or more per mile, whereas 

 the latest and lowest beaches are nearly horizontal. The uplift is found 



