State | Colorado |
---|---|
Name | Pierre Shale--Lower unit |
Geologic age | Cretaceous |
Lithologic constituents |
Major
Sedimentary > Clastic > Mudstone > Shale
Minor
Sedimentary > Clastic > Mudstone > Claystone > Bentonite (Bed)
|
References | Tweto, Ogden, 1979, Geologic Map of Colorado: U.S. Geological Survey Special Geologic Map, scale 1:500,000. |
NGMDB product | |
Counties | Boulder - Cheyenne - Crowley - Custer - Douglas - El Paso - Fremont - Jefferson - Kiowa - Larimer - Lincoln - Otero - Pueblo |