The Quaternary geology of Fond du Lac County consists of glacial deposits and landforms dating to the last part of the Wisconsin Glaciation (ca. 20,000 to 12,000 yr BP) and nonglacial deposits and landforms of Holocene age (11,700 yr BP to present). Glacial till and meltwater sediment were deposited by the Green Bay and Lake Michigan Lobes of the Laurentide Ice Sheet. The Kettle Interlobate Moraine formed in eastern Fond du Lac County where these two lobes abutted. Glacial lake sediment was deposited in lowlands when the Green Bay Lobe impounded drainage forming glacial lakes Fond du Lac and Oshkosh.