The Perdrix Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

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 ...

(

Frasnian The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage. Major reef-building was under way during th ...

) age in 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 ...

. It named for

Roche à Perdrix Roche à Perdrix is a mountain in Alberta's Rockies, Canada. It is located south of Highway 16 on the eastern border of Jasper National Park, and is part of the Fiddle Range, one of the easternmost ranges of the Canadian Rockies. It is one of the ...

in Jasper National Park,

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

, by P.E. Raymond in 1930. It includes

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

of marine animals.

Lithology

The Perdrix Formation was deposited in a marine basin and consists primarily of black, bituminous

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

s. The upper portion includes

nodules Nodule may refer to: *Nodule (geology), a small rock or mineral cluster *Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, p ...

and thin nodular beds of argillaceous

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

that increase in frequency upwards and laterally toward the reefs of the

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, ...

.Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba, p. 925-926. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. .

Thickness and Distribution

The Perdrix Formation is present as outcrops in the front and main ranges of the

Canadian Rockies The Canadian Rockies (french: Rocheuses canadiennes) or Canadian Rocky Mountains, comprising both the Alberta Rockies and the British Columbian Rockies, is the Canadian segment of the North American Rocky Mountains. It is the easternmost part ...

from the Kakwa Lakes area in northeastern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

to the Ram River area of Alberta. It is also recognized in the subsurface immediately adjacent to the mountain front. Thicknesses range from about to .

Relationship to Other Units

The Perdrix Formation overlies the Maligne Formation or, where the Maligne is absent, the Flume Formation. It is conformably overlain by the Mount Hawk Formation and the contact is gradational. Laterally it interfingers with the Peechee Formation and the reefs of the

Paleontology

Tentaculids are common throughout the Perdrix Formation, and brachiopods and

pelecypod Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biva ...

s are present in the more limestone-rich portions.

References

* {{Western Canadian Sedimentary Basin, Canadian Rockies=yes Devonian Alberta Devonian southern paleotropical deposits Frasnian Stage Geologic formations of Alberta Western Canadian Sedimentary Basin Fossiliferous stratigraphic units of North America Paleontology in Alberta Shale formations Limestone formations of Canada

Lithology

Thickness and Distribution

Relationship to Other Units

Paleontology

See also

References