Ice Sheet Case Study - Minnesota, USA Flashcards
1
Q
What is the name of the large ice sheet that covered the USA, and how thick was it?
A
The Laurentide ice sheet, over 1km thick.
2
Q
What is the major erosional feature caused by an ice sheet?
A
An ellipsoidal basin, which is a large isostatic depression.
3
Q
When was the ellipsoidal basin across the northern USA and Canada formed?
A
During the quaternary period, which was 2 million years ago.
4
Q
What erosional effect did the Laurentide ice sheet have on the landscape?
A
The highest peaks are only 500-700m, and there are striations that show the direction of ice movement.
5
Q
What depositional effect did the Laurentide ice sheet have on the landscape?
A
The till deposits are over 160m deep, and in addition with glacial meltwater this creates very fertile red silt farmland.
