Cretaceous, undifferentiated (SDKu;0)

Cretaceous, undifferentiated

Black opaline spiculite, gray to black shale, yellow-brown to gray chalk, gray silty clay, and pink quartz-rich sandstone. Includes the Split Rock Creek Formation and other near-shore facies of the Dakota Formation, Graneros Shale, Greenhorn Formation, Carlile Shale, Niobrara Formation, and Pierre Shale. Thickness up to 400 ft (122 m).

State	South Dakota
Name	Cretaceous, undifferentiated
Geologic age	Upper to Lower Cretaceous
Lithologic constituents	Major Sedimentary > Clastic > Mudstone > Shale (Bed)Gray to black shale Sedimentary > Chemical > Chert (Bed)Black opaline spiculite. Sedimentary > Carbonate > Limestone > Chalk (Bed)Yellow-brown to gray chalk Minor Unconsolidated > Fine-detritalGray silty clay Sedimentary > Clastic > Sandstone (Bed)Pink quartz-rich sandstone
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	NGMDB product page for 96370
Counties	Brookings - Hutchinson - Lake - Lincoln - McCook - Minnehaha - Moody - Turner

Cretaceous, undifferentiated

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.