384 
GLACIAL DRIFTS IN MINNESOTA 
In referring to the several drift sheets of Minnesota, the term 
“old drift” has been used for the glacial deposits that were first 
in the earth’s history, and “young drift” for that which is later. 
The “old” or old-looking drift belongs to several glacial stages, 
while the “young” or younger-looking drift belongs all to one 
stage, the Wisconsin stage by name. Soonest disposed of, the 
simpler the descriptions, as to oldest, old and young drift-sheets, 
their names, in order of age, Nebraskan, Kansan, Illinoian, 
Iowan (?) and Wisconsin, may now be used consistently for the 
drifts and Glacial stages in Minnesota, and these titles also are 
more convenient. 
So it is also for the terms “red” and “gray” drifts. That 
Glacial drift that came from northeast (Labrador), and that from 
the north (Patricia) are “red;” while that which came from north¬ 
west (Kewatin) is “gray.” There are two “old gray,” and one 
“young gray” drift-sheets; and one “old red” and two “young 
red” drift-sheets involved in Minnesota, so that it is simplest to 
keep in mind the terms Labradorian, Patrician and Kewatin, for 
description of them as to the direction of their coming both for 
the glaciers and the deposits that the latter made. 
The earliest understanding of the Driftless Area, as one that 
was completely surrounded by glaciers at one time by their coming 
from the north and closing in around it so as to meet on the south, 
has now given way to the simpler understanding that glaciers 
come up to that Area first in the west and north. At later stages, 
glaciers came up to it on the east and south. At no time was there 
an impassable barrier of ice, or drift, to stop rivers from the 
Driftless Area from discharging south. At no time were animals 
and plants shut in from their fellows in the temperate climate to 
the south. No reason remains for considering this Driftless Area 
as a special problem, but all matters relating to the drift around 
it are similar to those elsewhere. The Upper Mississippi River 
is thus similar to the Missouri and the Ohio rivers as to Glacial 
history. Some unsolved problems remain in relation to each of 
the Glacial stages, but these are, simple so far as concerns the 
drift deposits of Minnesota. They are comparable to the difficulty 
of seeing in the dark, the evidence is obscure, and artificial lights 
have too much color variance. The unsolved problems may be 
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