Steele Shale and Niobrara Formations

Steele Shale (Ks) - Gray soft marine shale containing numerous bentonite beds and thin lenticular sandstone. Niobrara Formation (Kn) - Light-colored limestone and gray to yellow speckled limy shale.
State Wyoming
Name Steele Shale and Niobrara Formations
Geologic age Upper Cretaceous
Lithologic constituents
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Mudstone > Claystone > Bentonite
Sedimentary > Clastic > Sandstone
NGMDB product
Counties Carbon