GLACIAL FEATURES OF CENTRAL WISCONSIN

GLACIAL HISTORY OF PORTAGE COUNTY

The accumilation of ice covering continential land masses is not a new occurence in earth's history. Large sheets of ice advanced changing the landscape by eroding bare rock and carrying materials long distances. The glaciers melted and recessed, affecting the land by leaving behind till and blocks of ice that eventually created glacier features like moraines, drumlins and kettle lakes.

The Green Bay Lobe of the Wisconsin glaciation had the most influence on the landscape in Portage County. As the glacial lobe retreated two prominent moraines were created, the Outer and Arnott. A moraine is defined as a mound, ridge or other accumilation of till deposited by direct action of glacier ice.

Arnott Moraine Arrnot Moraine east of Stevens Point off County Highway J.

Stratified outwash plain Stratified layers of glacial till on the outwash plain between the Outer and Arnott Moraines on County Highway B



















DRUMLIN FIELD IN WAUPACA COUNTY

3/4 mile northeast of the town of Sheridan

A drumlin is a smoothly rounded, elongated and oval hill, mound or ridge of compact glacial till. Built under the margin of the ice,it is shaped by the glaciers flow. It usually has a blunt nose facing the direction from which the ice approached and a gentle slope tapering in the other direction.

Follow the highlighted portions for a virtual field trip of the drumlin fields in Waupaca County. The yellow highlighted circle is the starting point of the tour. From this point proceed east along the salmon colored dashed line. Following the USGS topographic map are several pictures that were taken while driving the tour outlined.

drumlin field map

Side view of drumlin Lateral view of the elongated slope of the drumlin looking northwest from the tour starting point (County Highway Q and Haase Road intersection).











Example of drumlin Head-on view of a large drumlin on Haase Road travelling east. The orientation of this drumlin is east to west.












example of erratics left by glacier At the corner of Haase Road and Bartel Road looking northeast, in the distance one can see boulders that were desposited by the glacier as it receeded from the area. Smaller boulders have been transported from as far away as the Upper Peninsula of Michigan.









Another example of erractics Notice the various types of boulders that are visable. Most of them are varying types of granite, local in origin that give us an idea of the composition of the bedrock. This location can be found by driving an 1/8 of a mile south on County Highway Q.









Kettle lake This is the final stop on the tour. Continuing south on County Highway Q, turn west on Grenlie Road follow to Foley Drive turn north. West of the Foley Drive and Indian Valley Road intersection, lie a series of small kettle lakes. These kettle lakes were formed where a block of ice broke off, was buried and melted creating the lakes (This lake was still covered by ice when this photo was taken, however not from the glacier).









Sources:

Moraines: Short Field Trip for Portage County Area written by Marshall E. Parry 1983 Geog./Geol Dept. University of Wisconsin-Stevens Point

A Glacial History of Portage County, Wisconsin written by Marshall E. Parry 1980 Geog./Geol Dept. University of Wisconsin-Stevens Point

Drumlins: Short Field Trip for Portage County Area written by Marshall E. Parry 1983 Geog./Geol Dept. University of Wisconsin-Stevens Point

This lovely virtual field trip was created by Mark N. Benishek II, Andrew Jennings, Tim Lahti, Rhody Jakusz, and last but not least Amy Strobel.

Created on 5-16-96

Last updated 5-16-96 10:41am CST