The surface of the county is underlain by Cretaceous sedimentary bedrock, topped with unconsolidated Quaternary sediments.

It consists of one meter of late Quaternary aeolian sediments overlying bedrock.

Guccione, M., 1983, Quaternary sediments and their weathering history in northcentral Missouri.

The investigations of Quaternary sediments identified palaeochannels containing important environmental material contemporaneous with the nearby site.

The island has a relatively thin (up to 2 m) cover of Quaternary marine sediments overlying the Ordovician limestone bedrock.

Most of these lie offshore, and some control basins that contain large thicknesses of Quaternary sediments.

The Quaternary sediments are of marine and fluvial alluvium of recent age.

Gently undulating surface of the land area is hilly and consists of flysch strata and Quaternary sediments.

Quaternary sediments consisting of clay, silt, various grades of sand and gravel underlie the city.

The trough is now hidden by a cover of Quaternary sediments and volcanic rocks.