Pierre Shale

Pierre Shale
Pierre Shale
Stratigraphic range: Campanian PreꞒ Ꞓ O S D C P T J K Pg N
	A broken concretion with fossils inside; Late Cretaceous Pierre Shale near Ekalaka, Montana
Type	Geological formation
Underlies	Fox Hills Formation
Overlies	Niobrara Formation
Lithology
Primary	Shale
Location
Coordinates	44°23′42″N 100°24′43″W / 44.395°N 100.412°W
Region	North America
Country	United States, ; Canada
Type section
Named for	Fort Pierre
Named by	Meek & Hayden, 1862

The Pierre Shale /pɪər ʃeɪl/ is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in Canada^[1] to New Mexico.

The Pierre Shale was described by Meek and Hayden in 1862 in the Proceedings of the Academy of Sciences (Philadelphia). They described it as a dark-gray shale, fossiliferous, with veins and seams of gypsum, and concretions of iron oxide. The Pierre Shale is about 700 feet (210m) thick at the type locality. It overlies the Niobrara division and underlies the Fox Hills beds. It was named for an occurrence near Fort Pierre on the Missouri River in South Dakota.^[2]

The Pierre Shale is of marine origin and was deposited in the Western Interior Seaway. It is correlative with other marine shales that occur farther west, such as the Bearpaw Shale, Mancos Shale and the Lewis Shale.^[3] It correlates with the Lea Park Formation in central Alberta.^[4] The Pierre is overlain by marginal marine deposits of the Fox Hills Formation.

Most of the formation was deposited in the Campanian Age of the late Cretaceous. However, the discovery of fossils of Baculites baculus Meek and Hayden in the uppermost beds of the Pierre Shale in the Raton, New Mexico area show that deposition continued here into the early Maastrichtian.^[5]

Mineral resources

The Pierre Shale is the host formation for commercial oil deposits in the Florence and Canon City fields in Fremont County, Colorado, and the Boulder Oil Field in Boulder County, Colorado. More recently, natural gas has been extracted in the Raton Basin in southern Colorado. The shale formation is usually too impermeable for hydrocarbon extraction, but produces in areas where it is naturally fractured or fractured by artificial means.

Paleofauna

Hesperornithiformes

Hesperornithiformes reported from the Pierre Shale Formation
Genus	Species	Location	Stratigraphic position
Brodavis	B. varneri	South Dakota	Sharon Springs member.^[6]
Brodavis	B. sp.	Manitoba	Pembina member.^[6]
Hesperornis	H. bairdi	South Dakota	Sharon Springs member.^[6]
	H. chowi	Manitoba & South Dakota	Pembina, Millwood, & Sharon Springs members.^[6]
	H. lumgairi	Manitoba	Pembina member.^[6]
	H. macdonaldi	Manitoba & South Dakota.	Gammon, Pembina, Millwood(?), & Sharon Springs members.^[6]
	H. mengeli	Manitoba & South Dakota.	Pembina & Sharon Springs members.^[6]
	H. regalis	Manitoba, South Dakota, & Kansas	Gammon, Pembina, & Sharon Springs members.^[6]

Ornithischians

Claosaurus affinis (hadrosaurid indet) "Pedal phalanx (lost)."^[7]

Marine vertebrates

Invertebrates

Inoceramus
Several species of ammonites
Several species of Baculites

References

^ Canadian Fossil Discovery Centre. "All About Bruce". Archived from the original on 2014-11-06.
^ M.E. Maclachlan, New Mexico Geological Society Guidebook, 27th Field Conference, Vermejo Park, 1976
^ G.A. Izett and others, The Pierre Shale near Kremmling, Colorado, and its correlation to the east and the west, US Geological Survey, Professional Paper 684-A.
^ Lexicon of Canadian Geologic Units. "Lea Park Formation". Archived from the original on 2013-02-21. Retrieved 2009-03-23.
^ Sealey, Paul L.; Lucas, Spencer G. (2019). "Baculites Baculus Meek and Hayden, 1861 (Earliest Maastrichtian) from the Uppermost Pierre Shale in the Raton basin of Northeastern New Mexico and its Significance" (PDF). New Mexico Geological Society Field Conference Series. 70: 73–80. Retrieved 4 September 2020.
^ ^a ^b ^c ^d ^e ^f ^g ^h Aotsuka, K. and Sato, T. (2016). Hesperornithiformes (Aves: Ornithurae) from the Upper Cretaceous Pierre Shale, Southern Manitoba, Canada. Cretaceous Research, (advance online publication). doi:10.1016/j.cretres.2016.03.003
^ "Table 20.1," in Weishampel, et al. (2004). Page 442.
^ "[dinosaur] Tylosaurus saskatchewanensis (new species) + African araripemydid turtle Taquetochelys decorata". dml.cmnh.org. Retrieved 2019-02-04.

[1] Canadian Fossil Discovery Centre. "All About Bruce". Archived from the original on 2014-11-06.

[2] M.E. Maclachlan, New Mexico Geological Society Guidebook, 27th Field Conference, Vermejo Park, 1976

[3] G.A. Izett and others, The Pierre Shale near Kremmling, Colorado, and its correlation to the east and the west, US Geological Survey, Professional Paper 684-A.

[lexicon-4] Lexicon of Canadian Geologic Units. "Lea Park Formation". Archived from the original on 2013-02-21. Retrieved 2009-03-23.

[sealey-lucas-2019-5] Sealey, Paul L.; Lucas, Spencer G. (2019). "Baculites Baculus Meek and Hayden, 1861 (Earliest Maastrichtian) from the Uppermost Pierre Shale in the Raton basin of Northeastern New Mexico and its Significance" (PDF). New Mexico Geological Society Field Conference Series. 70: 73–80. Retrieved 4 September 2020.

[lumgairi2016-6] ^ ^a ^b ^c ^d ^e ^f ^g ^h Aotsuka, K. and Sato, T. (2016). Hesperornithiformes (Aves: Ornithurae) from the Upper Cretaceous Pierre Shale, Southern Manitoba, Canada. Cretaceous Research, (advance online publication). doi:10.1016/j.cretres.2016.03.003

[table-20-1-442-7] "Table 20.1," in Weishampel, et al. (2004). Page 442.

[8] "[dinosaur] Tylosaurus saskatchewanensis (new species) + African araripemydid turtle Taquetochelys decorata". dml.cmnh.org. Retrieved 2019-02-04.

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