Gray and brown silt, silty clay, some very fine sand, reddish brown along the Red River.
Gray to brownish gray clay and silty clay, reddish brown in the Red River Valley, some sand and gravel locally.
Gray to brown lignitic sands and silty to sandy lignitic clays, many seams of lignite; some limestone and glauconite.
Gray to white sandstones; loose quartz sand, tuffaceous sandstone, volcanic ash, and brown sandy clays; petrified wood locally.
Light gray to light brown clay, sandy clay, silt, sand, and some gravels.
Yellow to gray siltstones, sandstones, and clays with thin tuffaceous beds; some lenses of black chert gravel; petrified wood locally.
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.
Light gray to orange-brown clay, sandy clay, and silt; much sand and gravel locally.
Brown lignitic clays, silts and sands; some sideritic glauconite may weather to brown ironstone in lower part.
Gray calcareous clays which may weather to black soil; siltstone, taffaceous clays and some volcanic ash beds
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.
Brown to gray liginitic clays with thin interbeds of lignite or micaceous sands; calcareous shale, petrified wood, and bluish fossilferous clay locally.
Light gray to brown liginitic clays with thin interbeds of limonitic sands or lignite; near base,calcareous, glauconitic, and fossiliferous beds may weather to black soil.
Tan to orange clay, silt, and sand with a large amount of basal gravels.