The Redknife Formation is a

stratigraphical 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: lithostrat ...

unit of

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, w ...

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 olde ...

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

Redknife River The Redknife River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River. The Redknife Formation, a stratigraphical unit of the Western Canadian Sedimentary Basin was named for the river. Course The Re ...

, a tributary of the Mackenzie River, and was first described in the banks of the Trout River, north of

Trout Lake, Northwest Territories Sambaa K'e ( Slavey language: "place of trout"; formerly Trout Lake) is a "Designated Authority" in the Dehcho Region of the Northwest Territories, Canada. The community is located near the Alberta border, east of Fort Liard, on the shore of th ...

, at Table Rock Rapids by Belyea and McLaren in 1962.

Lithology

The Redknife Formation is divided into the

Jean Marie Member 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, north ...

(base) and an upper unnamed

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especia ...

unit. The Jean Marie Member is composed of argillaceous,

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel wh ...

y and

dolomitic Dolomite () is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite. An alternative name sometimes used for the dol ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

iferous

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 wh ...

. The carbonates are massive east of

Fort Nelson Fort Nelson may refer to: Canada *Fort Nelson, British Columbia, a town *Fort Nelson River, British Columbia *Fort Nelson (Manitoba) (1670–1713), an early fur trading post at the mouth of the Nelson River and the first headquarters of the Hudson' ...

and west of the

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 ...

border. The upper Redknife consists of calcareous

shales Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...

with silty limestone and

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, ...

interbeds. To the south and east, the shales grade into limestone and siltstone, and it becomes dolomitic in 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 ...

arch. The Redknife formation contains common

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secre ...

and

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, ...

fossils.

Oil/gas production

Gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

is produced from the

in the Greater Sierra filed east of

Fort Nelson, British Columbia Fort Nelson is a community in northeast British Columbia, Canada, within the Northern Rockies Regional Municipality (NRRM). It held town status prior to 6 February 2009, when it amalgamated with the former Northern Rockies Regional District to f ...

Distribution

The Redknife Formation occurs in outcrops in the southern

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 in the sub-surface in north-eastern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost Provinces and territories of Canada, province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include ...

, also reaching into north-western

. The maximum thickness of the upper shales is , and the lower carbonates are up to . The Jean Marie Member is found in outcrops south of the Mackenzie River between

Kakisa Kakisa (Slavey language: ''K’agee''; ''between the willows'') is a "Designated Authority" in the South Slave Region of the Northwest Territories, Canada. The community is located on Kakisa Lake, and is southeast of Fort Providence. Originally ...

and Blackstone River. It grades westwards into the

facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formatio ...

of the

Fort Simpson Formation The Fort Simpson Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin. It takes the name from the settlement of Fort Simpson, and was first described in well Briggs Turkey Lake No. 1 (located south-east ...

. East of the Peace River Arch it turns into the

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonat ...

s of the

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 Trout ...

Relationship to other units

The Redknife Formation is conformly overlain by the

and overlies the

Tathlina Formation The Tathlina Formation is a geologic formation in Northwest Territories. It preserves fossils dating back to the Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end ...

northern Alberta Northern Alberta is a geographic region located in the Canadian province of Alberta. An informally defined cultural region, the boundaries of Northern Alberta are not fixed. Under some schemes, the region encompasses everything north of the ce ...

and the

and

. The Fort Simpson Formation replaces the Redknife Formation to the west. The Redknife Formation can be correlated with the

Nisku Formation The Winterburn Group is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin. It takes the name from Winterburn area located west of Edmonton, and was first described in well ''P.A. Pyrcz No. 1'' by Imperial Oil Lim ...

and upper part of the

Ireton Formation The Woodbend Group is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin. It was first described in the ''British American Pyrcz No. 1'' well by Imperial Oil geological staff in 1950. Lithology The Formation is co ...

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 ...

Subdivisions

The

is designated as the lower part of the Redknife Formation where it is represented by massive

or silty

s. The Jean Marie Member was deposited during the

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 t ...

age. It is named for the

Jean Marie River Jean Marie River (Slavey language: ''Tthek'éhdélį'' or ''Tthek'edeli'' "water flowing over clay") is a "Designated Authority" in the Dehcho Region of the Northwest Territories, Canada. The community is located on the Jean Marie River where i ...

References

Geologic formations of British Columbia Geologic formations of Alberta Geologic formations of the Northwest Territories Devonian southern paleotropical deposits Upper Devonian Series Devonian British Columbia Devonian Alberta Devonian Northwest Territories Shale formations Limestone formations of Canada Siltstone formations Dolomite formations {{Canada-geologic-formation-stub