Dakota Formation

Light- to reddish-brown, medium- to coarse-grained quartz and minor feldspar sandstone grading upward to a fine- to medium-grained, quartz and minor feldspar sandstone. Contains a middle, gray silty clay unit, and interbeds of gray to dark-gray shale in the upper portion. Thickness up to 450 ft (137 m).
State South Dakota
Name Dakota Formation
Geologic age Upper to Lower Cretaceous
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)Light- to reddish-brown, medium- to coarse-grained quartz and minor feldspar sandstone grading upward to a fine- to medium-grained, quartz and minor feldspar sandstone.
Minor
Sedimentary > Clastic > Mudstone > Shale (Bed)Interbeds of gray to dark-gray shale in the upper portion.
Unconsolidated > Fine-detritalContains a middle, gray silty clay unit.
References

Tomhave, D.W., and Schulz, L.D., 2004, Bedrock Geologic Map Showing Configuration of the Bedrock Surface in South Dakota East of the Missouri River, South Dakota Geological Survey, GM 9, scale 1:500,000.

NGMDB product
Counties Clay - Hutchinson - Lincoln - Turner - Union