Average annual precipitation gradually increases from 30 inches in the north to 36 inches in the south. Annual snowfall shows a similar trend, with 40 inches in the north and 50 inches in the south. Bedrock is not exposed in the sub-subsection. Devonian sandstone and shale are localized along the eastern edge, Mississippian shale underlies the center, and Mississippian sandstone is in the southwest. More than 80 percent of the ground moraine is flat, with slopes in the 0 to 6 percent slope class.
Ground moraine forms a broad plain.
Individual hills of the ground moraine are several miles in area, but are seldom higher than 80 feet. The topography of the end moraines is more rolling, with slopes in the 7 to 15 percent slope class. Less than 1 percent of the end moraines have slopes greater than 15 percent. Major rivers that cross the sub-subsection are the Huron and Raisin. Fine-textured soils, primarily silt loams and clay loams, are more common on the eastern edge.