The Keg River Formation is a

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostrati ...

unit of

Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in Fra ...

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 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 ...

Description

It takes the name from the Keg River, a tributary of the

Peace River The Peace River (french: links=no, rivière de la Paix) is a river in Canada that originates in the Rocky Mountains of northern British Columbia and flows to the northeast through northern Alberta. The Peace River joins the Athabasca River in th ...

, and was first described in the California Standard Steen River 2-22-117-5W6M well (situated north of

Zama Lake Zama Lake is a large lake in Mackenzie County, in north-western Alberta, Canada. Major Ernest Wilson Hubbell, Chief Inspector of the Dominion Land Survey, recorded the name "Zammah River" in his field notes as the transliteration of the name of ...

) by J. Law in 1955.

Lithology

The Keg River Formation is composed of dark

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 ...

with intercrystalline or vuggy

porosity Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...

and

wackestone Under the Dunham classification (Dunham, 1962Dunham, R.J., 1962. Classification of carbonate rocks according to depositional texture. In: W.E. Ham (Ed.), Classification of Carbonate Rocks. American Association of Petroleum Geologists Memoir. Amer ...

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 ...

. The Rainbow Member and upper Keg River Member are reef formations deposited in the Rainbow, Zama and Bitscho sub-basins.

Distribution

The Keg River Formation occurs in the subsurface from northeastern to northwestern Alberta and its southern border is defined by the Peace River Arch. It varies in depth from to .

Relationship to other units

The Keg River Formation is conformably overlain by the

Muskeg Formation The Muskeg Formation is a geologic formation of Middle Devonian (Givetian) age in the Western Canada Sedimentary Basin. It extends from the plains of northwestern Alberta to northeastern British Columbia, and includes important petroleum and natur ...

and

unconformably An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...

overlays the Chinchaga Formation. It is equivalent to the Pine Point Formation,

Hume Formation The Hume Formation is a geologic formation in the Northwest Territories, Canada. It preserves fossils dating back to the Devonian period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation ma ...

and

Nahanni Formation The Nahanni Formation is a stratigraphical unit of Givetian age in the Western Canadian Sedimentary Basin. It takes the name from Nahanni Butte, a prominent ridge at the confluence of the South Nahanni River and Liard River, and was first descr ...

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, ...

and the

Northwest Territories The Northwest Territories (abbreviated ''NT'' or ''NWT''; french: Territoires du Nord-Ouest, formerly ''North-Western Territory'' and ''North-West Territories'' and namely shortened as ''Northwest Territory'') is a federal territory of Canada. ...

and to the Winnipegosis Formation in

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 ...

and eastern

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 ...

Economic geology

Petroleum geology

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 Keg River reefs in the

and Rainbow Lake areas of north-western

References

{{Western Canadian Sedimentary Basin, Northwest_Plains=yes, Fort_Nelson=yes Stratigraphy of Alberta Stratigraphy of British Columbia Stratigraphy of the Northwest Territories Devonian southern paleotropical deposits Givetian Stage