GLACIAL DRIFTS IN MINNESOTA 
391 
drift of Iowa, and there is none other that can be, so that at 
present the problem here is very simple. There is no known 
Iowan drift in Minnesota. Details as to all the separate drift 
sheets, excepting one in the Wisconsin stage, are not shown on 
plate xxxiv, but they will be described later. They are indicated 
on plates xxxv, and xxxvi. 
In simplest terms, the Kewatin drift-sheet of the Wisconsin 
stage must serve as pattern for the interpretation of the Kewatin 
Kansan drift, and for the Kewatin Nebraskan drift. That the 
Patrician and Labradorian glaciers of the Wisconsin stage should 
be eliminated before comparison of the earlier and the latest drifts 
is made, is obvious. Three “gray’’ drift-sheets came from Kewa¬ 
tin across the northwest comer of Minnesota, and out across the 
south end of the state, so that, unless differences can be shown, 
it may be assumed that coming from the same place and going 
by the same path to the same outlet involves a similarity of form 
and movement. Likewise the “red’’ Labradorian Wisconsin serves 
as a paradigm for the “red” Illinoian sheet. The Patrician Wis¬ 
consin glacier, as shown on plate xxxiv is unique. 
With the Kewatin glacier of the Wisconsin stage in mind, (see 
plate xxxv) the Kewatin glacier of the Nebraskan, or first, stage 
compares as follows: At the south boundary line of Minnesota 
the Nebraskan glacier was about twice as wide as was the Wis¬ 
consin glacier. They came both from the same source in Kewatin 
or above Manitoba, as is shown by the character of their drift 
contents, which are alike. They traveled the same directions and 
the same routes. Consequently, the first glacier should be expected 
to have gone twice as far, more or less, than the last one did, 
or to a point beyond the Missouri River to the south, or else, 
to sublobe and deploy widely. That is not a Minnesota problem, 
however, as to how far that first glacier went. The problem for 
this State is what it did here. 
During its retreat, the last glacier left a practically continuous 
sheet of bouldery drift, or till, and many patches of gravel as 
outwash by streams from the glacier. The natural assumption 
is that the first one did likewise. But there are some differences 
to be noted. The first glacier passed over new surface on which 
the streams were at lowest gradient, the valleys were deep but 
