The Beaverfoot Formation is a stratigraphic unit of Late Ordovician ( Ashgill age) to Early Silurian ( Llandovery) age. It is present on the western edge of the

Western Canada Sedimentary Basin The Western Canadian Sedimentary Basin (WCSB) underlies of Western Canada including southwestern Manitoba, southern Saskatchewan, Alberta, northeastern British Columbia and the southwest corner of the Northwest Territories. This vast sedimentary ...

in the Rocky Mountains of British Columbia and Alberta, and the

Purcell Mountains The Purcell Mountains are a mountain range in southeastern British Columbia, Canada. They are a subrange of the Columbia Mountains, which includes the Selkirk, Monashee, and Cariboo Mountains. They are located on the west side of the Rocky Mounta ...

of British Columbia. It consists of carbonate rocks, and was named for the

Beaverfoot Range The Beaverfoot Range () is a mountain range of the Canadian Rockies, located in southeastern British Columbia. The range extends from Cedared Creek near Spillimacheen north to the Kicking Horse River The Kicking Horse River is in the Canadian ...

at Pedley Pass southeast of Golden, British Columbia by L.D. Burling in 1922. The formation is fossiliferous and is known for its brachiopod faunas. It also contains

rugose corals The rugosa, also called the tetracorallia or horn coral, are an extinct order of solitary and colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., '' Caninia'', '' Lophophyllidium'', '' Neoza ...

and

conodont Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, which ...

s.Jin, J., Caldwell, W.G.E. and Norford, B.S. 1989. Rhynchonellid brachiopods from the Upper Ordovician Lower Silurian Beaverfoot and Nonda formations of the Rocky Mountains of British Columbia. Geological Survey of Canada, Bulletin 396, p. 21-59.

Thickness and lithology

The Beaverfoot Formation is about 500 m (1640 ft) thick at its type section in Pedley Pass. It was deposited in shallow tropical waters on the western edge of a carbonate platform as limestone, much of which has been altered to

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

. Chert nodules are present in some beds.

Distribution and relationship to other units

The Beaverfoot Formation is present in the western ranges of the Rocky Mountains of British Columbia and forms cliffs along the eastern wall of the

Rocky Mountain Trench The Rocky Mountain Trench, also known as the Valley of a Thousand Peaks or simply the Trench, is a large valley on the western side of the northern part of North America's Rocky Mountains. The Trench is both visually and cartographically a s ...

. It is also present in the Purcell Range west of Radium, British Columbia, and in the main ranges of the Alberta Rockies between the

Clearwater Clearwater or Clear Water may refer to: Places Canada * Clear Water Academy, a private Catholic school located in Calgary, Alberta * Clearwater (provincial electoral district), a former provincial electoral district in Alberta * Clearwater, Briti ...

and North Saskatchewan Rivers. It disconformably overlies the Mount Wilson Formation or older rocks. It is conformably overlain by the Tegart Formation in the western ranges, and unconformably overlain by the

Late Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wher ...

Cairn Formation The Cairn Formation is a geologic formation of Late Devonian (Frasnian) age in the Western Canada Sedimentary Basin. It was named for the Cairn River near its junction with the Southesk River in Jasper National Park by D.J. McLaren in 1955.McLaren, ...

to the east in Alberta.Norford, B.S. 1969. Ordovician and Silurian stratigraphy of the southern Rocky Mountains. Geological Survey of Canada, Bulletin 176.

Paleontology

The Beaverfoot Formation spans the Ordovician-Silurian boundary and records faunal changes that occurred during the Ordovician-Silurian extinction events. It is known for fossil

rhynchonellid The taxonomic order Rhynchonellida is one of the two main groups of living articulate brachiopods, the other being the order Terebratulida. They are recognized by their strongly ribbed wedge-shaped or nut-like shells, and the very short hing ...

atrypid ''Atrypa'' is a genus of brachiopod with shells round to short egg-shaped, covered with many fine radial ridges (or costae), that split further out and growth lines perpendicular to the costae and 2-3 times wider spaced. The pedunculate valve is ...

, and

pentamerid Pentamerida is an order of biconvex, impunctate shelled, articulate brachiopods that are found in marine sedimentary rocks that range from the Middle Cambrian through the Devonian.Moore, Lalcker and Fischer, 1952, Invertebrate Fossils, McGraw-Hil ...

brachiopods, most of which have undergone silicification and can be separated from the dolomite matrix by treatment with acid. It also contains

s and

('' Deiracorallium prolongatum'', '' Salvadorea distincta'', '' Bighornia patella'', '' Bighornia cf. bottei'').Beaverfoot Formation
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org

References

{{Western Canadian Sedimentary Basin, Canadian Rockies=yes Western Canadian Sedimentary Basin Geologic formations of British Columbia Geologic formations of Alberta Ordovician Alberta Ordovician British Columbia Silurian Alberta Silurian British Columbia Dolomite formations Limestone formations Shallow marine deposits Ordovician southern paleotropical deposits Silurian southern paleotropical deposits Silurian northern paleotropical deposits

Thickness and lithology

Distribution and relationship to other units

Paleontology

See also

References