Benton Shale
Benton Shale Stratigraphic range: Cretaceous | |
---|---|
Type | Formation |
Underlies | Niobrara Formation |
Overlies | Dakota Sandstone |
Lithology | |
Primary | Shale |
Other | Limestone, sandstone, bentonite |
Location | |
Region | Montana, Wyoming, North Dakota, South Dakota, Colorado, Nebraska |
Country | United States |
Type section | |
Named for | Fort Benton, Montana |
The Benton Shale (also Benton Formation or Benton Group) is a geologic formation in Montana, Wyoming, North Dakota, South Dakota, Colorado, Kansas, and Nebraska.[1] It preserves fossils dating to the Cretaceous Period. The term Benton Limestone has also been used to refer to the chalky portions of the strata, especially the upper beds of the strata presently classified as Greenhorn Limestone. The Benton classification is obsolete in some regions, having been replaced by the ascending sequence Graneros Shale, Greenhorn Limestone, and Carlile Shale.[2][3]
The classification derives its name from Fort Benton, a small city in Montana on the Upper Missouri River.
See also
References
- ↑ National Geologic Map Database - Geolex, USGS
- ↑ Donald E. Hattin (1962). "Stratigraphy of the Carlile Shale (Upper Cretaceous) in Kansas". State Geological Survey of Kansas. Kansas Geological Survey, University of Kansas, Lawrence, Kansas (Bulletin 156). Retrieved 2018-08-04.
- ↑ Donald E. Hattin (1962). "Stratigraphy and Depositional Environment of Greenhorn Limestone (Upper Cretaceous) of Kansas". State Geological Survey of Kansas. Kansas Geological Survey, University of Kansas, Lawrence, Kansas (Bulletin 209). Retrieved 2018-08-04.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 8 July 2014.
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