Keg River Formation
Encyclopedia
The Keg River Formation is a stratigraphical
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....

 unit of Givetian age
Geochronology
Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...

 in the Western Canadian Sedimentary Basin
Western Canadian Sedimentary Basin
The Western Canadian Sedimentary Basin is a vast sedimentary basin underlying of Western Canada including southwestern Manitoba, southern Saskatchewan, Alberta, northeastern British Columbia and the southwest corner of the Northwest Territories. It consists of a massive wedge of sedimentary rock...

.

It takes the name from the Keg River, a tributary of the Peace River
Peace River (Canada)
The Peace River 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 flows into the Slave River, a tributary of the Mackenzie River. The Mackenzie is the 12th longest river in the world,...

, and was first described in the California Standard Steen River 2-22-117-5W6M well (situated north of Zama Lake
Zama Lake
Zama Lake is a large lake in the Mackenzie County, in north-western Alberta, Canada.It is located approximately west of High Level, at the confluence of Zama River and Hay River. The lake covers and forms an intricate river, lakes and wetland system. The Hay-Zama Lakes complex is a Ramsar site...

) by J. Law in 1955.

Lithology

The Keg River Formation is composed of dark dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

 with intercrystalline or vuggy porosity
Porosity
Porosity or void fraction is a measure of the void spaces in a material, and is a fraction of the volume of voids over the total volume, between 0–1, or as a percentage between 0–100%...

 and wackestone limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

.

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

Hydrocarbon production

Oil
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 is produced from the Keg River reefs in the Zama Lake
Zama Lake
Zama Lake is a large lake in the Mackenzie County, in north-western Alberta, Canada.It is located approximately west of High Level, at the confluence of Zama River and Hay River. The lake covers and forms an intricate river, lakes and wetland system. The Hay-Zama Lakes complex is a Ramsar site...

 and Rainbow Lake
Rainbow Lake, Alberta
Rainbow Lake is a small town in northern Alberta, Canada. It is located west of High Level at the end of Highway 58, in MacKenzie County.The town carries the name of the nearby lake, formed on the Hay River, that was so called due to its curved shape....

 areas of north-western Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

.

Distribution

The Keg River Formation occurs in the sub-surface from north-eastern to north-western Alberta and its sothern border is defined by the Peace River Arch. It varies in depth from 10 metres (32.8 ft) to 300 metres (984.3 ft).

Relationship to other units

The Keg River Formation is conformably overlain by the Muskeg Formation
Muskeg Formation
The Muskeg Formation is a stratigraphical unit of Givetian age in the Western Canadian Sedimentary Basin.It takes the name from the Muskeg arctic soil that covers the northern reaches of western Canada, and was first described in the California Standard Steen River 2-22-117-5W6M well by J...

 and unconformably
Unconformity
An unconformity is a buried erosion 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 of time before deposition of the younger, but the term is used to describe...

 overlays the Chinchaga Formation.

It is equivalent to the Pine Point Formation
Pine Point Formation
The Pine Point Formation is a stratigraphical unit of Givetian age in the Western Canadian Sedimentary Basin.It takes the name from Pine Point, a promontory on the south shore of the Great Slave Lake, west of Fort Resolution, and was first described in outcrop on the shore of the lake between Pine...

, Hume Formation and Nahanni Formation
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 proeminent ridge at the confluence of the South Nahanni River and Liard River, and was first described in outcrop on the south face of the mountain by C.O...

 in north-eastern British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 and the Northwest Territories
Northwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...

 and to the Winnipegosis Formation in Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....

 and eastern Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

.
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