Gray to brownish gray clay and silty clay, reddish brown in the Red River Valley, some sand and gravel locally.
Light gray to orange-brown clay, sandy clay, and silt; much sand and gravel locally.
Greenish gray sideritic clay in upper part may weather to brown ironstone; yellow to brown clays and fossiliferous marl in lower part may weather to black soil. Ironstone concretions near base.
Light gray to light brown clay, sandy clay, silt, sand, and some gravels.
Tan to orange clay, silt, and sand with a large amount of basal gravels.
White to light gray massive sands with interbedded clays; some thin beds of lignite or lignitic sands and shales.
Brown silty clay with basal glauconitic, fossiliferous silts which may weather to ironstone locally.
Brown lignitic clays, silts and sands; some sideritic glauconite may weather to brown ironstone in lower part.
Gray to brown lignitic sands and silty to sandy lignitic clays, many seams of lignite; some limestone and glauconite.
Claibourne Group
Alluvial deposits of present streams
Alluvial deposits on one or more terrace levels