- Cody Shale
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Cody Shale
Stratigraphic range: Late CretaceousType Sedimentary Sub-units see text Underlies Mesaverde Formation Overlies Frontier Formation Thickness 500-1000 m Lithology Primary shale Location Named for Cody, Wyoming Named by C. T. Lupton, 1916[1] Region Montana folded belt province, Central Montana uplift, Big Horn basin, Powder River basin, Wind River basin Country United States Extent Wyoming, Idaho, Montana The Cody Shale is a Late Cretaceous geologic formation. It is mapped in Wyoming, Idaho, and Montana.
The formation is described by W.G. Pierce as follows: upper part is buff, sandy shale and thinly laminated buff sandstone; lower part is dark gray, thin-bedded marine shale.[2]
The formation is divided into many members (alphabetical)[3]:
- Ardmore Bentonite Beds (WY)
- Belle Fourche Member (MT, WY)
- Carlile Member (MT, WY)
- Claggett Member (MT, WY)
- Eldridge Creek Member (MT)
- Gammon Ferruginous Member (MT, WY)
- Greenhorn Calcareous Member (MT)
- Niobrara Member (MT, WY)
- Sage Breaks Member (WY)
- Shannon Sandstone Member (MT, WY)
- Steele Member (WY)
- Sussex Sandstone Member (WY)
- Telegraph Creek Member (MT, WY)
- Wallace Creek Tongue (WY)
References
- ^ Lupton, C.T., 1916, Oil and gas near Basin, Big Horn County, Wyoming, IN Contributions to economic geology, 1915; Part 2, Mineral fuels: U.S. Geological Survey Bulletin, 621-L, p. L157-L190.
- ^ Pierce, W.G., 1997, Geologic map of the Cody 1 degree x 2 degrees quadrangle, northwestern Wyoming: U.S. Geological Survey, Miscellaneous Geologic Investigations Map I-2500, scale 1:250000.
- ^ http://ngmdb.usgs.gov/Geolex/NewUnits/unit_7568.html USGS GEOLEX, retrieved 18 April 2010
Categories:- Mesozoic geologic formations
- Geologic formation stubs
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