Mount Whyte Formation
The Mount Whyte Formation is a stratigraphic unit that is present on the western edge of the Western Canada Sedimentary Basin in the southern Canadian Rockies and the adjacent southwestern Alberta plains.[3] It was deposited during Middle Cambrian time and consists of shale interbedded with other siliciclastic rock types and limestones. It was named for Mount Whyte in Banff National Park by Charles Doolittle Walcott, the discoverer of the Burgess shale fossils, and it includes several genera of fossil trilobites.[1]
Mount Whyte Formation Stratigraphic range: Middle Cambrian ~509–500 Ma | |
---|---|
Type | Formation |
Underlies | Cathedral Formation |
Overlies | Gog Group |
Thickness | Up to 176 metres (578 ft)[1] |
Lithology | |
Primary | Shale, limestone |
Other | Sandstone, conglomerate |
Location | |
Coordinates | 51°24′32″N 116°16′16″W |
Region | Canadian Rockies |
Country | |
Type section | |
Named for | Mount Whyte |
Named by | Charles Doolittle Walcott[2] |
Lithology and deposition
The Mount Whyte Formation was deposited during Middle Cambrian time in shallow water at the western margin of the North American Craton.[3][4][5] It consists mainly of shale interbedded with other siliciclastic rock types and limestone. In the Mount Whyte area it can be subdivided into three units:[1]
- Upper member: Shale interbedded with oolitic limestone.
- Middle member: Shale with thin beds of sandstones and conglomerates, grading into impure limestones at the top.
- Basal member: Thin-bedded limestones and sandy limestones with lenticular beds of pebbly sandstone and shale partings.[1]
Distribution and stratigraphic relationships
The Mount Whyte Formation outcrops in the southern Rocky Mountains of southwestern Alberta and southeastern British Columbia, and is present in the subsurface beneath the southwestern Alberta plains where it grades onto the Earlie Formation. It grades into the Snake Indian Formation to the north and Naiset Formation to the west. It disconformably overlies the Lower Cambrian Gog Group and is conformably overlain by the Cathedral Formation.[3][6]
Paleontology
The Mount Whyte Formation includes Olenellus and other fossil trilobites that establish its Middle Cambrian age by biostratigraphy.[1][7][8]
References
- Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. ISBN 0-920230-23-7.
- Walcott, C.D. 1908. Nomenclature of some Cambrian Cordilleran formations. Smithsonian Miscellaneous Collections, vol. 53, no. 1, 14 pp.
- Slind, O.L., Andrews, G.D., Murray, D.L., Norford, B.S., Paterson, D.F., Salas, C.J., and Tawadros, E.E., Canadian Society of Petroleum Geologists and Alberta Geological Survey (1994). "The Geological Atlas of the Western Canada Sedimentary Basin (Mossop, G.D. and Shetsen, I., compilers), Chapter 8: Middle Cambrian and Early Ordovician Strata of the Western Canada Sedimentary Basin". Archived from the original on 2016-07-01. Retrieved 2018-07-13.CS1 maint: multiple names: authors list (link)
- Aitken, J.D. 1971. Control of lower Paleozoic sedimentary facies by the Kicking Horse Rim, southern Rocky Mountains, Canada. Bulletin of Canadian Petroleum Geology, vol. 19, no. 3, p. 557-569.
- Aitken, J.D. 1997. Stratigraphy of the Middle Cambrian platformal succession, southern Rocky Mountains. Geological Survey of Canada, Bulletin 398, 322 p.
- Alberta Geological Survey. "Alberta Table of Formations, May 2019" (PDF). Alberta Energy Regulator. Retrieved 24 March 2020.
- Walcott, C.D. 1917. Geology and paleontology IV. Smithsonian Miscellaneous Collections, vol. 67, no. 3, p. 61-115.
- Rasetti, F. 1951. Middle Cambrian stratigraphy and faunas of the Canadian Rocky Mountains. Smithsonian Miscellaneous Collections, vol. 116, no. 5, 277 p.
References
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 31 July 2014. Retrieved 8 July 2014.