GLACIAL DRIFTS IN MINNESOTA 
397 
from the main glacier through the Lake Superior Basin. The main 
glacier in both cases, of course, went southwest across Michigan 
into Illinois. 
The Illinoian glacier brought a stony “red” drift into Minnesota, 
but since it crossed a district in northwestern Wisconsin where 
remnants of the Kansan Kewatin drift, at least, were lying, it 
shows a perceptable mixture of the Manitoba limestone pebbles 
in the till. The Illinoian glacier made a pronounced morainic 
belt, with gravel knolls and stony hills. At its terminus it made 
an outwash of gravel filling the valley of Chub creek 100 feet and 
more deep with it and diverting the creek by a cross-cut to its 
tributary, the Little Cannon River. The main Cannon River 
above Northfield was then, of course, non-existant. 
Up to that time the upper Saint Croix River joined the Missis¬ 
sippi River at the west side of Hennepin County (No. 14, plate 
xxxiv) and the Minnesota at the north side of Scott County 
(No. 15) and went across Dakota County (No. 9). From the 
position of the Illinoian glacier it may be seen that all of the Mis¬ 
sissippi drainage was cut off and diverted, from the north to the 
south side of Dakota County, through Chub Creek Valley and 
broadly over the limestone ledge into the Little Cannon River. 
That appears to be the event that started the Cannon Falls, and 
gave the canyon-like feature to the valley below the Falls. As 
the Illinoian glacier retreated, however, the Mississippi River 
went back into its old course. 
The northernmost parts of the great dust deposit that is known 
as the loess lies over parts of the Illinoian drift, as it does also 
over parts of the Kansan and Nebraskan in Minnesota. The 
Wisconsin glaciers overrode the loess, of course, being later than 
it. The loess gives therefore a simple criterion for the distinction 
of the “old red” and “young red” drifts in theory although not 
many places in practice. 
When the term Iowan Drift was applied, as at first, to that 
which is now called the Kansan stage in Iowa, its acceptance in 
Minnesota would have been quite logical. And after the title was 
re-defined and made to designate a drift-sheet contemporaneous 
with the loess the name Iowan loess was logical here too. But 
the search for a drift-sheet of the same age as the loess has not 
