The Winterburn Group is a stratigraphical unit of

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 Age or AGE may refer to: Time and its effects * Age, the amount of time someone or something has been alive or has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

in the

Western Canadian 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 takes the name from Winterburn area located west of

Edmonton Edmonton ( ) is the capital city of the Canadian province of Alberta. Edmonton is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Alberta's central region. The city ancho ...

, and was first described in well ''P.A. Pyrcz No. 1'' by Imperial Oil Limited in 1950.Geological Staff, Imperial Oil Limited, Western Division, 1950. Devonian Nomenclature in Edmonton Area, Alberta, Canada. Bulletin of the

American Association of Petroleum Geologists The American Association of Petroleum Geologists (AAPG) is one of the world's largest professional geological societies with more than 40,000 members across 129 countries as of 2021. The AAPG works to "advance the science of geology, especially as ...

, Vol. 34, No. 9, pp. 1807-1825.

Lithology

The Winterburn Group is composed of silty

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 ...

evaporite An evaporite () is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocea ...

, 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 ...

, red and green

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

, silty

and

. Pinnacle

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

s develop in the Nisku Formation.

Hydrocarbon production

Oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

is produced from the Nisku Formation in the

Pembina oil field The Pembina oil field is one of the largest and most prolific conventional oil fields in the province of Alberta, Canada. The mature field is centered on Drayton Valley and is named for the Pembina River, which crosses the region from southwest to ...

Distribution

The Winterburn Group reaches a maximum thickness of west of the Leduc reef system. In

central Alberta Central Alberta is a region located in the Canadian province of Alberta. Central Alberta is the most densely populated rural area in the province. Agriculture and energy are important to the area's economy. Geography Central Alberta is bordere ...

it is 30 to 70m thick. It thins out over the Peace River Arch, and disappears in north-eastern

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, ...

Subdivisions

The Winterburn Group is composed, from bottom to top, of the Nisku, Calmar and Graminia Formations. The Graminia Formation includes the carbonate Blue Ridge Member west of the

Rimbey Rimbey is a town in central Alberta, Canada. It is located at the junction of Highways 20 and 53 in the Blindman River valley area approximately northwest of Red Deer and southwest of Edmonton. Provincially, Rimbey is part of the Rimbey-Roc ...

-Meadowbrook reef trend.

Relationship to other units

The Winterburn Group is conformably overlain by the Wabamun Group and overlays the Ireton Formation, except in the Peace River Arch, where it rests on the

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

basement A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, ...

. It is correlated with the Birdbear Formation and part of the

Three Forks Group The Three Forks Group is a stratigraphical unit of Famennian age in the Williston Basin. It takes the name from the city of Three Forks, Montana, and was first described in outcrop near the city by A.C. Peale in 1893 (for the Three Forks Shale). ...

Saskatchewan Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...

, with the Southesk Formation and Alexo Formation in 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 ...

and with the

Redknife Formation The Redknife Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin. It takes the name from Redknife River, a tributary of the Mackenzie River, and was first described in the banks of the Trout River, nor ...

and

Kakisa Formation The Kakisa Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin. It takes the name from the Kakisa River, a tributary of the Mackenzie River, and was first described in outcrop on the banks of the Trou ...

in north-eastern

References

{{Western Canadian Sedimentary Basin, Northeast_Plains=yes, Northwest_Plains=yes, Central_Plains=yes Stratigraphy of Alberta Devonian southern paleotropical deposits