Oldman Formation

Oldman Formation Stratigraphic range: Upper Cretaceous, 77.5–76.5 Ma PreЄ Є O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Belly River Group
Underlies	Dinosaur Park Formation
Overlies	Foremost Formation
Thickness	up to 328 feet (100 m)^[1]
Lithology
Primary	Sandstone
Other	Mudstone and bentonite
Location
Coordinates	49°37′41″N 112°53′23″W / 49.62806°N 112.88972°W / 49.62806; -112.88972 (Oldman Formation)Coordinates: 49°37′41″N 112°53′23″W / 49.62806°N 112.88972°W / 49.62806; -112.88972 (Oldman Formation)
Region	Western Canada Sedimentary Basin
Country	Canada
Type section
Named for	Oldman River
Named by	Russell, L.S. and Landes, R.W., 1940.^[2]

The Oldman Formation is a stratigraphic unit of Late Cretaceous (Campanian stage) age that underlies much of southern Alberta, Canada. It consists primarily of sandstones that were deposited in fluvial channel and floodplain environments. It was named for exposures along the Oldman River between its confluence with the St. Mary River and the city of Lethbridge, and it is known primarily for its dinosaur remains and other fossils.^[3]

Lithology

The Oldman Formation is composed primarily of light-colored, fine-grained sandstones. They are upward-fining, lenticular to sheet-like bodies that are yellowish, steep-faced and blocky in outcrop. The formation also includes lesser amounts of siltstone and mudstone.^[4]

Depositional Environments

The sediments of the Oldman Formation were deposited in fluvial channels (the sandstones) and a variety of channel margin, overbank and floodplain environments (the siltstones and mudstones). The formation is about 40 metres (130 ft) thick at Dinosaur Park in southeastern Alberta. It thickens toward the southwest, and northwestern Montana appears to have been the primary source of the sediments.^[4]

Relationship to other units

The Oldman Formation is a member of the Belly River Group (also known as the Judith River Group). It conformably overlies the Foremost Formation, and is separated from the overlying Dinosaur Park Formation by a regional disconformity. The sediments of the Oldman are superficially similar to those of the Dinosaur Park, which was included in the Oldman Formation prior to the recognition of the disconformity. The two formations can also be distinguished by petrographic and sedimentologic differences.^[3]^[4]

Age

The Oldman Formation was deposited during the middle Campanian, between about 77.5 and 76.5 million years ago.^[5] It lies fully within magnetic polarity Chron 33n.^[6]

Fauna

List of dinosaurs found in the formation:^[5]^[7]

Theropods

Theropods reported from the Oldman Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Daspletosaurus	D. torosus		Upper through lower	Several specimens	A tyrannosaurid	Daspletosaurus Dromaeosaurus Hesperonychus
Dromaeosaurus	Indeterminate			Teeth	A dromaeosaurid
Hesperonychus	H. elizabethae			Foot claw	A dromaeosaurid
Paronychodon	Indeterminate			Teeth	A troodontid
Ricardoestesia	R. isosceles				Misreported
Ricardoestesia	Indeterminate			Teeth	A dromaeosaurid
Saurornitholestes	S. langstoni			Partial remains	A dromaeosaurid
Troodon	T. formosus			Teeth, eggs, embryos	A troodontid, also found in the Dinosaur Park, Judith River, and Two Medicine Formations

Ornithischians

Ornithischians reported from the Oldman Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Albertaceratops	A. nesmoi		Lower		A ceratopsid	Albertaceratops Brachylophosaurus Chasmosaurus Parasaurolophus Wendiceratops
Albertadromeus^[8]	A. syntarsus		Upper		A thescelosaurid
Anchiceratops	Indeterminate				A ceratopsid
Brachylophosaurus	B. canadensis		Upper		A hadrosaurid
Coronosaurus	C. brinkmani		Upper		A ceratopsid
Chasmosaurus	C. brevirostris				Junior synonym of C. russelli.
Chasmosaurus	C. russelli		Upper		A ceratopsid, also found in the Dinosaur Park Formation
Corythosaurus	C. casuarius		Upper		A hadrosaurid, also found in the Dinosaur Park Formation
Parasaurolophus	P. walkerii		Upper		A hadrosaurid, also found in the Dinosaur Park Formation
Scolosaurus	S. cutleri		Upper		An ankylosaurid, may actually be from the Dinosaur Park Formation
Wendiceratops	W. pinhornensis		Lower		A centrosaurine discovered in 2015

Footnotes

↑ Lexicon of Canadian Geological Units. "Oldman Formation". Retrieved 2009-02-06.
↑ Russell, L.S. and Landes, R.W., 1940. Geology of the southern Alberta Plains; Geological Survey of Canada, Memoir 221.
1 2 Eberth, D.A. and Hamblin A.P. 1993. Tectonic, stratigraphic, and sedimentologic significance of a regional discontinuity in the upper Judith River Group (Belly River wedge) of southern Alberta, Saskatchewan, and northern Montana. Canadian Journal of Earth Sciences 30: 174-200.
1 2 3 Eberth, D.A. 2005. The geology. In: Currie, P.J., and Koppelhus, E.B. (eds), Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Indiana University Press: Bloomington and Indianapolis, p. 54-82. ISBN 0-253-34595-2.
1 2 Arbour, V. M.; Burns, M. E.; Sissons, R. L. (2009). "A redescription of the ankylosaurid dinosaur Dyoplosaurus acutosquameus Parks, 1924 (Ornithischia: Ankylosauria) and a revision of the genus". Journal of Vertebrate Paleontology 29 (4): 1117–1135. doi:10.1671/039.029.0405.
↑ Lerbekmo, J.F. 1989. The position of the 33-33r (Campanian) polarity chron boundary in southeastern Alberta. Bulletin of Canadian Petroleum Geology 37: 43-47.
↑ Weishampel, D.B., Barrett, P.M., Coria, R.A., Le Loueff, J., Xu X., Zhao X., Sahni, A., Gomani, E.M.P., & Noto, C.N. 2004. Dinosaur distribution. In: Weishampel, D.B., Dodson, P., & Osmólska, H. (Eds.). The Dinosauria (2nd Edition). Berkeley: University of California Press. Pp. 517-606.
↑ Brown, C. M.; Evans, D. C.; Ryan, M. J.; Russell, A. P. (2013). "New data on the diversity and abundance of small-bodied ornithopods (Dinosauria, Ornithischia) from the Belly River Group (Campanian) of Alberta". Journal of Vertebrate Paleontology 33 (3): 495. doi:10.1080/02724634.2013.746229.

References

D.A. Eberth. 1996. Origin and significance of mud-filled incised valleys (Upper Cretaceous) in southern Alberta, Canada. Sedimentology 43:459–477
Ryan, M. J., and Russell, A. P., 2001. Dinosaurs of Alberta (exclusive of Aves): In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 279–297.

Western Canadian Sedimentary Basin

Hydrocarbon history	Oil sands and heavy oil Frontier exploration and development Natural gas liquids Natural gas

Depositional Regions	Southern Alberta Central Alberta Northwestern Alberta Plains South-central Canadian Rockies foothills North-east Plains North-central foothills Liard River Fort Nelson Northern Rocky Mountains Fort St. John Saskatchewan Western Manitoba

Southern Alberta Plains	Cypress Hills FM Porcupine Hills FM Ravenscrag FM Edmonton GRP Belly River GRP Oldman FM Foremost FM Pakowki FM Milk River FM Colorado GRP Mannville GRP Ellis GRP Swift FM Rierdon FM Sawtooth FM Rundle GRP Banff FM Exshaw FM Bakken FM Wabamun FM Crowfoot FM Nisku FM Ireton FM Leduc FM Cooking Lake FM Beaverhill Lake GRP Elk Point GRP Canadian Shield

This article is issued from Wikipedia - version of the Friday, April 29, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.