Wisconsin Geospatial News

Green Bay lobe details revealed

No, this story isnt about a collective brain scan of this years Packers team. The word lobe also refers to a broad mass of glacial ice. The most recent glaciation over Wisconsin involved several such lobes, and the one that flowed southwesterly from modern Green Bay toward Madison, reaching its greatest extent 18,000 years ago, is designated as the Green Bay Lobe.

Now a new map of the southern part of the lobe shows the modern evidence of its previous dominance in the landscape. Moraines, outwash fans, drumlins, eskers, kames, and more are all there, and from their location and orientation a picture of ice and meltwater movement comes into focus.

The map covers an area between 88 and 90 degrees west longitude and between 42.5 and 44 degrees north latitude. Within that rectangle, the southwest and southeast corners are used for legends and inset maps. On the ground, the mapped features lie generally within a polygon bounded by the following municipalities (listed clockwise starting in the northwest): Friendship, Berlin, New Holstein, West Bend, Waukesha, Elkhorn, Brodhead, and Mount Horeb.

Glacial Landforms of the southern Green Bay lobe, southeastern Wisconsin is produced at 1:250,000 scale by the Wisconsin Geological and Natural History Survey. Also described as WGNHS Miscellaneous Map 52, this product is 30 inches high by 34 inches wide. It was not printed in quantity through traditional lithographic means; rather, copies are plotted on demand. A plot sells for $15 (shipping and tax extra). Contact WGNHS at 608/263-7389.