THE LOESS COVER ON THE ANTIGO FLATS OUTWASH PLAIN, NE WISCONSIN

“Antigo Flats” is the name given to the broad (~37 x 27 km in area) outwash plain that lies between the end moraines of the Green Bay, Langlade and Wisconsin Valley lobes of the Laurentide ice sheet, in NE Wisconsin. The outwash plain is covered by 0.5-1.5 m of loess, which generally thickens toward the moraines and in slight depressions on the plain itself. The state soil of Wisconsin - the Antigo silt loam - is found extensively in this area; it formed in the loess and outwash below. Occasionally, thin beds of silty or loamy alluvium exist between the loess and the underlying outwash. In this poster, we will show, via a series of maps created in ArcGIS, how this loess sheet varies in thickness and textural composition across the Flats, and on the nearby moraines. Using these data, we will outline the possible source areas for this loess, as well as the timing of loess deposition, as suggested by an OSL age from one site on the Flats.