QUATERNARY EOLIAN SAND OF THE CENTRAL PLAIN OF WISCONSIN

The Central Plain of Wisconsin is located in the basin of Glacial Lake Wisconsin, which formed when the Green Bay Lobe of the Laurentide Ice Sheet dammed the Wisconsin River (as described by Clayton and Attig, 1989). This basin was filled with approximately 100 meters of mostly glaciolacustrine sand. Glacial Lake Wisconsin likely drained catastrophically when the terminal moraine dam was breached. This late Pleistocene drainage of the lake was likely the first time the sandy lake plain was exposed to eolian reworking. Other potential times of eolian activity include the arid middle Holocene and possibly the late Holocene, which were periods of dune mobility across the more arid Great Plains. Previous studies have cited soil development as a relative age indicator of dune forms in the Central Plain, however to date there are no numerical age estimates for these sediments. This project provides the first numerical age control of eolian deposits in central Wisconsin with optical luminescence age estimates. These are important for understanding the links between past climates and eolian landforms in the humid Upper Midwest, and the timing of deglaciation of the Green Bay Lobe. The project includes significant undergraduate participation including field work, sediment analysis at the University of Wisconsin-Platteville and luminescence sample preparation at the University of Nebraska-Lincoln.