Greenhorn Limestone and Graneros Shale

Greenhorn Limestone- medium- to light-gray limestone interbedded with argillaceous limestone, marl and calcareous shale; contains Inoceramus fossils. Upper and lower contacts gradational. Approx. max thickness 30 ft. Graneros Shale- medium- to dark-gray, partly calcareous shale. Interbeds of siltstone, sandstone, and carbonaceous shale, and thin bentonite layers in upper part. Approx. max thickness 60 ft.
State Nebraska
Name Greenhorn Limestone and Graneros Shale
Geologic age Late Cretaceous
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale (Calcareous)
Sedimentary > Carbonate > Limestone (Bed)
Minor
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Siltstone (Bed)
Incidental
Sedimentary > Carbonate > Marlstone (Bed)
Comments Colorado Group
References
NGMDB product
Counties Burt - Butler - Cedar - Clay - Colfax - Cuming - Dakota - Dawes - Dixon - Dodge - Fillmore - Jefferson - Lancaster - Nuckolls - Polk - Saline - Saunders - Seward - Thayer - Thurston - York