Wisconsin Geography

From Encyclopedia of Wisconsin Environmental History
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It is hard to imagine that earth, sturdy and basic, can be so malleable as to be shaped into what we know today as Wisconsin Geography. The Wisconsin that we know today did not form overnight. It took thousands of years and numerous geological events to literally build the bedrock of this environmentally diverse state. The one notable event in Wisconsin's history was the Laurentide Ice Sheet, covering three-fourths of the state for over 16,000 years and drastically changing the landscape after it melted.

Glacial Reshaping

Map of Wisconsin around 25,000 B.C.
Map of Wisconsin around 25,000 B.C.. Source: Wisconsin Geological Survey

Wisconsin as it is known today was being shaped around 24,000 B.C. by a sheet of ice that covered all of Canada and parts of the northern United States. The glacier, known as the Laurentide Ice Sheet, moved through the north and east parts of Wisconsin carrying with it rock and sediment as it traveled. When the glacier stopped expanding it created lobes or ice faces that reached as high as 200 meters in height. These glacial boundaries are the same geological boundaries found today and drastically shaped the distribution of Wisconsin's natural resources. The four lobes from the northwest to southeast are the Superior, Chippewa, Wisconsin Valley and Green Bay. The northern lobes (Superior, Chippewa, Wisconsin Valley) dominated the northern part of the state while the Green Bay lobe encompassed the northeast and southeast to about the location on modern day Milwaukee. The land that was not covered in ice to the southwest is considered a driftless area, a place where the overall geography of the land was not altered by the glacier. Around 18,000 B.C. the Laurentide Ice Sheet began to melt and recede. The glacier left behind chunks of ice that were buried in the ground along with other rocks and sediment. These ice chunks slowly began to melt and fade away. The resulting outcome was the collapse of earth above causing divots called hummocky. Hummocky was usually accompanied by melt water that flooded the collapsed topsoil and helped form eskers in the winding moraines. These eskers were the reason that the Wisconsin Dells were created as melt water eroded the rock barriers of Glacial Lake. The borders of the glacier can be outlined by the hummocky that separates the driftless area from the lands that are littered with moraines. Any sediment or rock that is deposited via glacier in any way is called moraine. The thousands of lakes that dot the Wisconsin geography were created either by hummocky or by moraines that filled up valleys such as one of Wisconsin's state parks Devil's Lake. Wisconsin was overwhelmingly flooded for a period of time following the retreat of the glacier. Once the glacier had melted entirely contemporary Wisconsin was born.

Human Interaction

In the way that Wisconsin's landscape is diverse and to some extent partitioned, the processes of refining the natural resources is diverse and almost exclusive to parts of the landscape. For example, frac sand mining in Wisconsin is centered primarily to the northwest at the edge of the Superior Lobe. The minerals and sediments deposited there range from iron to zinc and more to the north. The north also has some of the most dense forests and poor soil quality in Wisconsin mainly due to the glacial drift that scattered rocks and sediment into the ground. The northern forests were logged almost bare in the 1800's with a billion plus board feet cut down and sold. For early settlers there was no other use for the land as most attempts at farming were unsuccessful and mining companies set up shop in the middle-western part of the state. The real farming breadbasket of Wisconsin lies in the southern part of the state. The driftless area to the southwest was grasslands for thousands of years and even hosted Mastodons in the early millenniums of the glacier. Forests were chopped down at a hastened pace in order to access the rich soil below. Much of the rocky land was sold to immigrants hailing from Germany and Northern Europe From what the Laurentide Ice Sheet gave the first European settlers of Wisconsin to reshape the people have taken the diverse landscape and made it their own.

Contemporary Wisconsin

The lands of Wisconsin have changed drastically since the glacier first receded. New technology in agriculture has helped remove the rocks and sediments from otherwise difficult cultivation spots. In return, forests were cut down extensively almost to the point of no return. Once there was a sea of pine trees to the north as far as one can see but now the sea has been replaced by rows of pines planted by the lumber companies. The large underground lakes from the glacier are being used to fuel the agricultural power house Wisconsin has become. Many of the hummocky borders are still intact despite land

References

Bradbury, Kenneth, Dr. Wisconsin Geological Overview. Wisconsin Geological & Natural History Survey. Last modified 2013. Accessed December 3, 2015. http://wgnhs.uwex.edu.

Additional Published Resources

  • Ostergren, Robert C. and Thomas R. Vale. Wisconsin Land and Life. Madison: University of Wisconsin Press, 1997. eBook Collection (EBSCOhost), EBSCOhost (accessed November 24, 2015).
  • Wisconsin Cartographers Guild. Wisconsin's Past and Present. Madison: University of Wisconsin Press, 1998.

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