Glacier melting is an ongoing process
February 17, 2002

The continental glacier and its many lobes that covered a large portion of Wisconsin began melting over 10,000 years ago. The melting of a glacier is on-going. When more ice melts in the "toe area" (the southern-most advance) than accumulates in the area where the glacier began - it appears that the glacier is "receding".

Saying that a glacier recedes is a common error. Glaciers to not move backwards - they melt, most commonly in the toe area.

When, over a period of, perhaps, hundreds (or even thousands) of years, the melting continued, the area previously covered took on a look of a lunar landscape.

It has been said that in our area of east central Wisconsin (Manitowoc County) the ice was over one mile thick (high). As the glacier made advances, a tremendous amount of debris such as ground-up rock, soil, clay - whatever the abrasive power of this great moving weight could scrape and move - was brought into and through our county.

When the melting began, millions of tons of material was slowly deposited to form our present-day soil. This is why we find chunks of red granite and other materials in our soil. These "northern Wisconsin" rocks were moved here by the advancing glacier - then "dumped."

We are blessed with numerous features with those mysterious glacier-related names such as kettles, kames, moraines, drumlins, eskers and others. There are other features in our area that are called gifts of the glacier but are, in reality, land forms that existed here before the glacier advanced. These features were, in fact, uncovered and exposed by the glacier scraping away adjacent debris.

There are several areas of our county where the (Silurian) bedrock has been exposed by glacial action. This bedrock was formed when we were a warm salt sea - south of the equator - and is millions of years older than the glacier - but that is another story!

One of the best places to observe the exposed bedrock is along Rockledge Road, northwest of Mishicot. Fossil coral that formed in shallow sea water can be found in the rock near this public road. Most other areas of exposed bedrock are on private property - making the site at Rockledge Road important.

The scenic value of this road as it curves up the rock ledge and the fact that the exposure was due to glacial action are two of the reasons that part of the Ice Age National Scenic Trail is located there.

Scientists say that we may again be covered by an advancing glacier - but don't wait up for it!