The city is located in the Southeastern Wisconsin glacial till plains that were created by the Wisconsin glaciation during the most recent ice age. The soil in area is a mixture of well-draining material, loess, and loam, which all overlie a layer of glacial till. Most of the City of Cedarburg is located on top of a Silurian limestone deposit. There were several quarries active in the area, including the now-defunct Groth Quarry in Zeunert Park where excavators discovered fossils from a prehistoric reef. The early settlers utilized the area's limestone as a building material, and some mid-19th-century limestone structures still stand today.