Tertiary, undifferentiated (SDTu;0)

Tertiary, undifferentiated

Light greenish-brown and light yellowish-tan to orangish-brown clay, silty clay, and fine sand; light-brown to pink siltstone; green, massive, orthoquartzite conglomerate; and multicolored quartz- and feldspar-rich sand and gravel. Includes equivalents of the Ogallala Group Ash Hollow, Valentine, and Fort Randall Formations. Also includes the Thin Elk, Bon Homme, Herrick, Medicine Root, and "western derived" gravels. Thickness up to 70 ft (21 m).

State	South Dakota
Name	Tertiary, undifferentiated
Geologic age	Pliocene to Miocene
Lithologic constituents	Major Sedimentary > Clastic > Mixed-clastic > Conglomerate-sandstoneGreen, massive, orthoquartzite conglomerate Sedimentary > Clastic > SiltstoneLight-brown to pink siltstone Unconsolidated > Fine-detritalLight greenish-brownand light yellowish-tan to orangish-brown clay, silty clay, and fine sand Minor Unconsolidated > Coarse-detritalMulticolored quartz- and feldspar-rich sand and gravel
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	Bon Homme - Brule - Charles Mix - Hutchinson - Turner - Yankton

Tertiary, 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.