Toad-Grayling Formation

Last updated
Toad-Grayling Formation
Stratigraphic range: Early to Middle Triassic
Type Geological formation
Sub-unitsToad Formation
Grayling Formation
Underlies Liard Formation
Overlies Fantasque Formation
Lithology
Primary Siltstone, shale
Other Limestone, dolomite
Location
Coordinates 59°2′8″N125°13′11″W / 59.03556°N 125.21972°W / 59.03556; -125.21972 (Toad-Grayling Formation) Coordinates: 59°2′8″N125°13′11″W / 59.03556°N 125.21972°W / 59.03556; -125.21972 (Toad-Grayling Formation)
RegionFlag of British Columbia.svg  British Columbia
CountryFlag of Canada (Pantone).svg  Canada
Type section
Named forToad and Grayling Rivers
Named byE.D. Kindle, 1944 [1]

Toad Formation, Grayling Formation, and Toad-Grayling Formation are obsolete names for the strata of the Early to Middle Triassic Doig and Montney Formations. [2] [3] They were applied in the foothills and Rocky Mountains of northeastern British Columbia, on the western edge of the Western Canada Sedimentary Basin. Although the names are considered obsolete, their usage persists. [3]

Contents

The Toad and Grayling strata have yielded fossils of marine organisms, including ammonites, brachiopods, and bivalves. [4]

Stratigraphic history

The Toad and Grayling Formations were originally described by E.D. Kindle in 1944, [1] who named them for the Toad and Grayling Rivers, which are tributaries of the Liard River in northeasternmost British Columbia. They were combined as the Toad-Grayling Formation by A.D. Hunt and J.D. Ratcliffe in 1959. [4] [5] The Toad-Grayling was replaced by the Doig and Montney Formations by J.H. Armitage in 1962, [2] and the names are now considered obsolete, although their usage persists. [3]

Lithology

The Grayling Formation consists of dolomitic siltstone and silty shale, with minor silty limestone, dolomite, and very fine-grained sandstone. It reaches a maximum thickness of about 460 metres (1500 ft). The overlying Toad Formation is more calcareous and less dolomitic than the Grayling. It consists of dark grey calcareous siltstone and silty limestone, with minor amounts of silty dolomite and calcareous sandstone and, in the lower part, minor thin, randomly dispersed lenses and nodules of phosphate. It reaches a maximum thickness of about 825 metres (2700 ft). [3] [4]

Relationship to other units

The Grayling Formation unconformably overlies the Permian Fantasque Formation. It is equivalent to the lower Montney Formation in the subsurface of the Peace River plains [2] and to the Phroso Siltstone Member of the Sulphur Mountain Formation in west-central and southwestern Alberta. Its contact with the overlying Toad Formation is gradational. [3] [4]

The Toad Formation is conformably overlain by the Liard Formation. North of the Peace River it is overlain, possibly unconformably, by the Ludington Formation, and in the Liard River area it is unconformably overlain by the Fort St. John Group. It is laterally equivalent to the Doig Formation and the upper two-thirds of the Montney Formation in the subsurface of the Peace River plains, [2] and to part of the Llama Member of the Sulphur Mountain Formation in west-central and southwestern Alberta. [3] [4]

See also

Related Research Articles

Montney Formation

The Montney Formation is a stratigraphical unit of Lower Triassic age in the Western Canadian Sedimentary Basin in British Columbia and Alberta.

Bullhead Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin of northeastern British Columbia and western Alberta. It was first defined by F.H. McLearn in 1918 as the Bullhead Mountain Formation, but later was upgraded to group status. It consists of the Cadomin and Gething Formations, although some early workers included the Bluesky Formation and others in the group.

Fernie Formation

The Fernie Formation is a stratigraphic unit of Jurassic age. It is present in the western part of the Western Canada Sedimentary Basin in western Alberta and northeastern British Columbia. It takes its name from the town of Fernie, British Columbia, and was first defined by W.W. Leach in 1914.

The Belloy Formation is a stratigraphical unit of Permian age in the Western Canadian Sedimentary Basin.

Redknife Formation

The Redknife Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.

The Schooler Creek Group is a stratigraphic unit of Middle to Late Triassic age in the Western Canadian Sedimentary Basin. It is present in northeastern British Columbia. It was named for Schooler Creek, a left tributary of Williston Lake, and was first described in two oil wells northwest of Fort St. John, by F.H. McLearn in 1921. Exposures along Williston Lake serve as a type locality in outcrop.

The Baldonnel Formation is a stratigraphical unit of Carnian age in the Western Canadian Sedimentary Basin.

The Wabamun Formation is a stratigraphic unit of Late Devonian (Famennian) age in the Western Canada Sedimentary Basin. It takes the name from Wabamun Lake and was first described in the Anglo Canadian Wabamun Lake No. 1 well by Imperial Oil in 1950.

The Exshaw Formation is a stratigraphic unit in the Western Canada Sedimentary Basin. It takes the name from the hamlet of Exshaw, Alberta in the Canadian Rockies, and was first described from outcrops on the banks of Jura Creek north of Exshaw by P.S. Warren in 1937. The formation is of Late Devonian to Early Mississippian age as determined by conodont biostratigraphy, and it straddles the Devonian-Carboniferous boundary.

Viking Formation

The Viking Formation is a stratigraphical unit of Cretaceous age in the Western Canadian Sedimentary Basin.

Doig Formation Geological formation

The Doig Formation is a geologic formation of middle Triassic age in the Western Canadian Sedimentary Basin. It takes the name from Doig River, a tributary of the Beatton River, and was first described in the Texaco N.F.A. Buick Creek No. 7 well by J.H. Armitage in 1962..

Horn River Formation

The Horn River Formation is a stratigraphic unit of Devonian age in the Western Canadian Sedimentary Basin.

Elk Point Group

The Elk Point Group is a stratigraphic unit of Early to Middle Devonian age in the Western Canada and Williston sedimentary basins. It underlies a large area that extends from the southern boundary of the Northwest Territories in Canada to North Dakota in the United States. It has been subdivided into numerous formations, number of which host major petroleum and natural gas reservoirs.

The Liard Formation is a stratigraphic unit of Middle Triassic to Late Triassic age in the Western Canadian Sedimentary Basin that is present in northeastern British Columbia. It takes its name from the Liard River, and was first described from outcrops on the southern bank of that river, near Hell Gate Rapids in the Grand Canyon of the Liard, by E.D. Kindle in 1946.

The Alexo Formation a stratigraphic unit of Late Devonian age. It is present on the western edge of the Western Canada Sedimentary Basin in the central Rocky Mountains and foothills of Alberta. The formation consists primarily of dolomite. It is locally fossiliferous and includes remains of marine animals such as brachiopods and conodonts.

The Sulphur Mountain Formation is a geologic formation of Early to Middle Triassic age. It is present on the western edge of the Western Canada Sedimentary Basin in the foothills and Rocky Mountains of western Alberta and northeastern British Columbia. It includes marine fossils from the time shortly after the Permian-Triassic extinction event.

Bickford Formation

The Bickford Formation is a geologic formation of Early Cretaceous (Valanginian) age in the Western Canada Sedimentary Basin that consists primarily of nonmarine sediments. It is present in the northern foothills of the Canadian Rockies in northeastern British Columbia.

The Whitehorse Formation is a geologic formation of Late Triassic age. It is present on the western edge of the Western Canada Sedimentary Basin in western Alberta and northeastern British Columbia. It was first described as a member of the Spray River Formation by P.S. Warren in 1945, who named it for Whitehorse Creek, a tributary of the McLeod River south of Cadomin, Alberta. It was later raised to formation status.

Spray River Group

The Spray River Group is a stratigraphic unit of Triassic age. It is present on the western edge of the Western Canada Sedimentary Basin in the foothills and Rocky Mountains of western Alberta. It was originally described as the Spray River Formation by E.M. Kindle in 1924 and was later raised to group status. Its type section is located in the Spray River gorge at the southern end of Sulphur Mountain.


The Owen Creek Formation is a stratigraphic unit of Middle Ordovician age. It is present on the western edge of the Western Canada Sedimentary Basin in the Canadian Rockies of Alberta and British Columbia. It consists primarily of dolomite and was named for Owen Creek near Mount Wilson in Banff National Park by B.S. Norford in 1969.

References

  1. 1 2 Kindle, E.D. 1944. Geological reconnaissance along Fort Nelson, Liard and Beaver rivers, northeastern British Columbia and southeastern Yukon. Geological Survey of Canada, Paper 44-16, 16 p.
  2. 1 2 3 4 Armitage, J.H. 1962. Triassic oil and gas occurrences in northeastern British Columbia. Journal of the Alberta Society of Petroleum Geologists, vol. 10, p. 35-36.
  3. 1 2 3 4 5 6 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.
  4. 1 2 3 4 5 Gibson, D.W. 1975. Triassic rocks of the Rocky Mountain Foothills and Front Ranges of northeastern British Columbia and west-central Alberta. Geological Survey of Canada, Bulletin 247, 61 p.
  5. ↑ Hunt, A.D. and Ratcliffe, J.D. 1959. Triassic stratigraphy, Peace River area. Alberta and British Columbia, Canada. Bulletin of the American Association of Petroleum Geologists, vol. 43, no.3, p. 563-589.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.