The northern two-thirds of illinois, in the midwestern United states, was last covered by glaciers only,14,000 years ago. the re
st of the state was last covered by glaciers over 100,000 years ago. until the advent of modern agriculture, the recently glaciated area was a board, grassy swamp,cut by very few stream channels. in contrast, the area that was glaciated over 100,000 years ago is not swampy and has been cut by numerous stream valleys. why? Its an geology question
The area that was glaciated 100,000 years ago was not swampy because the water was frozen through out the whole year. There were no grasslands because the land was also covered with permafrost. And there were numerous stream valleys shaping the landscape because of the melting of the glaciers.
