1. Mineral Resources
  2. Online Spatial Data
  3. Geology
  4. by state
  5. Wyoming

Spearfish Formation

XML
JSON
Shapefile
Red shale, red siltstone, and white gypsum beds; gypsum beds especially abundant near base.
State Wyoming
Name Spearfish Formation
Geologic age Permian-Upper Triassic
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Clastic > Siltstone
Minor
Sedimentary > Chemical > Evaporite > Gypsum
References

Love, J.D. and Christiansen, A.C., 1985, Geologic Map of Wyoming: U.S. Geological Survey, scale 1:500,000.

https://pubs.er.usgs.gov/publication/70046739
NGMDB product
Counties Crook - Weston