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
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 ...
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
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 ...
. 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
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 ...
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
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 ...
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 ...
in
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
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 ...
in
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 ...
and
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. ...
. 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 ...
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 ...
.
Subdivisions
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 ...
is designated as the lower part of the Redknife Formation where it is represented by massive
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 ...
or silty
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.
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