Brown lignitic clays, silts and sands; some sideritic glauconite may weather to brown ironstone in lower part.
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.
Gray mixed with brown-to-red clay and silty clay; some sand and gravel locally.
Light gray to light brown clay, sandy clay, silt, sand, and some gravels.
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.
Gray and brown silt, silty clay, some very fine sand, reddish brown along the Red River.
Claibourne Group
Alluvial deposits of present streams