| State | South Dakota |
|---|---|
| Name | Spearfish Formation |
| Geologic age | Triassic to Permian |
| Lithologic constituents |
Major
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Minor
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Chemical > Evaporite > Gypsum (Bed)
|
| References | Martin, J.E., Sawyer, J.F., Fahrenbach, M.D., Tomhave, D.W., and Schulz, L.D., 2004, Geologic Map of South Dakota: South Dakota Geological Survey, GM 10, scale 1:500,000. |
| NGMDB product | |
| Counties | Butte - Custer - Fall River - Lawrence - Meade - Pennington |