State | Montana |
---|---|
Name | Niobrara through Belle Fourche Formation: Niobrara, Carlile, Greenhorn, and Belle Fourche Formations |
Geologic age | Cretaceous |
Lithologic constituents |
Major
Sedimentary > Clastic > Mudstone > Shale (Bed, Calcareous)
Sedimentary > Carbonate > Dolostone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Minor
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Clastic > Mudstone > Claystone > Bentonite (Bed)
Incidental
Sedimentary > Carbonate > Limestone > Chalk (Bed)Chalky aggregates of coccoliths and rhabdoliths
Sedimentary > Chemical > Phosphorite (Bed)grayish brown concretionary dolostone and limestone with phosphatic pellets
Sedimentary > Chemical > Chert (Bed)
|
References | Vuke, S.M., Porter, K.W., Lonn, J.D., and Lopez, D.A., 2007, Geologic Map of Montana - Compact Disc: Montana Bureau of Mines and Geology: Geologic Map 62-C, 73 p., 2 sheets, scale 1:500,000. This map was digitized in 2012 as a result of a contract between the U.S. Geological Survey and the Montana Bureau of Mines and Geology. |
NGMDB product | |
Counties | Fergus - Musselshell - Sweet Grass |