|Geologic age||Upper to Lower Cretaceous|
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.
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.
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.
|Counties||Clay - Hutchinson - Lincoln - Turner - Union|