Glacial Lake Scuppernong formed in front (south) of the retreating Green Bay Lobe in southern Wisconsin.
The land to the north was isostatically depressed because of the weight of the overlying ice; see GC5683T; IATCC - Earth's Rebound. Therefore, much of the land sloped toward the glacier. As the ice retreated to the north, melt-water became trapped between the ice and the terminal moraines. A large, shallow lake grew in size as the glacier retreated, then shrank over several thousand years as rebound took place.
Glacial Lake Scuppernong was connected for at least a short time with glacial Lake Yahara to the west. Drumlins and moraines would have been high ground (islands) within the lake.
Fig 53: Mickelson, David M. GEOLOGY OF THE ICE AGE NATIONAL SCENIC TRAIL. ©2011 by the Board of Regents of the University of Wisconsin System. Reprinted by permission of the University of Wisconsin
The extent of the lake has been determined by examining and analyzing the glacial, deglacial, and postglacial sediments. Soil pits and auger holes examined in the southern half of Jefferson County consisted predominantly of muck, laminated silt loam, and sandy loam. An auger hole in northwest Jefferson County showed topsoil down to approximately 1.5 feet. Clay, muck, laminated silt loam, and sandy loam then went down to approximately 35-40 feet. These are considered lake bottom sediment. Glacial till of sand and gravel was located from 40 feet down to the bedrock at approximately 60 feet. Radiocarbon dating of peat material supports the existence of the lake from approximately 15,000 - 12,500 years ago.
When the melting ice reached modern day Fort Atkinson, Lake Scuppernong began to drain through the Rock River. Approximately 12,000 years ago, the retreating ice reached the Lake Winnebago basin and the melt water was diverted to Lake Winnebago.
The area remains wet today because springs bubble out where groundwater reaches the surface. The water comes from rain infiltrating the gravelly Kettle Moraine just to the east and then flows to the lower elevation of the old lake bed. There are hundreds of springs along the edge of the Kettle Moraine.
IATCC is the cache designation to highlight a series of EarthCaches along the Ice Age National Scenic Trail grouped into a special category called "ColdCache."
The Ice Age Trail is one of eleven National Scenic Trails designated by the National Park Service. This unique trail is entirely within the state of Wisconsin and follows along the terminal moraine of the most recent glacier which retreated about 10,000 years ago.
This project is supported by the Ice Age Trail Alliance (IATA). The goal is to bring more visitors to the trail and promote public awareness, appreciation, and understanding of Wisconsin’s glacial landscape.
The IATA has created an awards program to encourage visits to the trail and ColdCache sites. This awards program is separate from, and in addition to, any other Geo- or EarthCache awards program.
A current list of approved ColdCache sites can be found on the “IATCC Bookmark List”. More information on the Ice Age Trail Atlas, the Companion Guide, the ColdCache Project and Awards Program can be found on the “ColdCache Webpage”
DNR Permission
The Geocache Notification Form has been submitted to Paul Sandgren of the Wisconsin DNR. Geocaches placed on Wisconsin Department of Natural Resource managed lands require permission by means of a notification form. Please print out a paper copy of the notification form, fill in all required information, then submit it to the land manager. The DNR Notification form and land manager information can be obtained at: www.wi-geocaching.com/hiding
Resources
Geology of the Ice Age National Scenic Trail; by David M. Mickelson, Louis J. Mahler Jr., and Susan L. Simpson
The Extent and Boundaries of Extinct Lake Scuppernong, Jefferson County, Southeastern Wisconsin; PhD Dissertation of Saif Ali Alhakimi; University of Wisconsin - Milwaukee 112 (2002)
Wisconsin Glaciation as seen in Jefferson County; by Robert Kondreck, Zelenda Koch, and Jim Gutkowski (UW-Milwaukee)
The coordinates take you to an area that would have been at the edge of Glacial Lake Scuppernong in present day southwestern Waukesha County.
To Claim this Find
Use binoculars to scan the surrounding area and describe what you see. Where are the high points? Do you think the high points would have been islands within Glacial Lake Scuppernong or moraines on the edges? Why?