| State | South Dakota |
|---|---|
| Name | Niobrara Formation |
| Geologic age | Upper Cretaceous |
| Lithologic constituents |
Major
Sedimentary > Carbonate > Limestone > Chalk (Bed)White to dark-gray argillaceous chalk, marl, and shale.
Sedimentary > Carbonate > Marlstone (Bed)White to dark-gray argillaceous chalk, marl, and shale.
Sedimentary > Clastic > Mudstone > Shale (Bed, Carbonaceous)White to dark-gray argillaceous chalk, marl, and shale; chalky carbonaceous shale.
Minor
Unconsolidated > Coarse-detrital > Sand (Bed)
Sedimentary > Clastic > Mudstone > Claystone > Bentonite (Bed)Contains thin, laterally continuous bentonite beds.
|
| 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 | Aurora - Beadle - Bon Homme - Brookings - Brown - Brule - Buffalo - Butte - Charles Mix - Clay - Codington - Corson - Custer - Davison - Day - Deuel - Douglas - Edmunds - Fall River - Faulk - Grant - Gregory - Hand - Hanson - Hutchinson - Jerauld - Kingsbury - Lake - Lincoln - McCook - Marshall - Meade - Miner - Moody - Pennington - Roberts - Sanborn - Shannon - Spink - Turner - Union - Yankton |