Redknife Formation
Encyclopedia
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 of Trout Lake, Northwest Territories
, at Table Rock Rapids by Belyea and McLaren in 1962.
unit. The Jean Marie Member is composed of argillaceous, silty
and dolomitic
fossiliferous
limestone
. The carbonates are massive east of Fort Nelson
and west of the Alberta
border. The upper Redknife consists of calcareous shales
with silty limestone and siltstone
interbeds. To the south and east, the shales grade into limestone and siltstone, and it becomes dolomitic in the Peace River
arch.
The Redknife formation contains common coral
and brachiopod
fossils.
is produced from the Jean Marie Member in the Greater Sierra filed
east of Fort Nelson, British Columbia
.
and in the sub-surface in north-eastern British Columbia
, also reaching into north-western Alberta
. The maximum thickness of the upper shales is 79 feet (24.1 m), and the lower carbonates are up to 15 feet (4.6 m). The Jean Marie Member is found in outcrops south of the Mackenzie River
between Kakisa
and Blackstone River. It grades westwards into the shale
facies
of the Fort Simpson Formation
. East of the Peace River Arch it turns into the carbonate
s of the Kakisa Formation
.
and overlies the Tathlina Formation in northern Alberta
and the Fort Simpson Formation
in British Columbia
and Northwest Territories
. The Fort Simpson Formation replaces the Redknife Formation to the west. The Redknife Formation can be correlated with the Nisku Formation and upper part of the Ireton Formation in central Alberta
.
or silty carbonate
s. The Jean Marie Member was deposited during the Frasnian
age. It is named for the Jean Marie River
.
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 Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
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 Redknife River
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:...
, a tributary of the Mackenzie River
Mackenzie River
The Mackenzie River is the largest river system in Canada. It flows through a vast, isolated region of forest and tundra entirely within the country's Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories...
, and was first described in the banks of the Trout River, north of Trout Lake, Northwest Territories
Trout Lake, Northwest Territories
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, in the southern NWT. It has no all-weather road, but can be reached by winter road early in the year.Population is 86 according to...
, at Table Rock Rapids by Belyea and McLaren in 1962.
Lithology
The Redknife Formation is divided into the Jean Marie Member (base) and an upper un-named shaleShale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
unit. The Jean Marie Member is composed of argillaceous, silty
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...
and dolomitic
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....
fossiliferous
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
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 carbonates are massive east of Fort Nelson
Fort Nelson, British Columbia
Fort Nelson is a town of approximately 5000 residents in British Columbia's northeastern corner. It is the administrative centre of the newly formed Northern Rockies Regional Municipality, a first for BC. The majority of Fort Nelson's economic activities have historically been concentrated in the...
and west of the 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...
border. The upper Redknife consists of calcareous shales
Shalës
Shalës is a municipality in the Elbasan District, Elbasan County, central Albania. The municipality consists of the villages Shalës, Licaj, Kurtalli, Xibrake, Xherie and Kodras....
with silty limestone and siltstone
Siltstone
Siltstone is a sedimentary rock which has a grain size in the silt range, finer than sandstone and coarser than claystones.- Description :As its name implies, it is primarily composed of silt sized particles, defined as grains 1/16 - 1/256 mm or 4 to 8 on the Krumbein phi scale...
interbeds. To the south and east, the shales grade into limestone and siltstone, and it becomes dolomitic in 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,...
arch.
The Redknife formation contains common coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
and brachiopod
Brachiopod
Brachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...
fossils.
Oil/gas production
GasNatural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
is produced from the Jean Marie Member in the Greater Sierra filed
Greater Sierra (oil field)
Greater Sierra is a large oil and gas field in northeastern British Columbia, Canada.It is located east and north from the town of Fort Nelson, extending to the Alberta and Northwest Territories borders .Drilling activity takes place largely during the winter months, when the otherwise soft muskeg...
east of Fort Nelson, British Columbia
Fort Nelson, British Columbia
Fort Nelson is a town of approximately 5000 residents in British Columbia's northeastern corner. It is the administrative centre of the newly formed Northern Rockies Regional Municipality, a first for BC. The majority of Fort Nelson's economic activities have historically been concentrated in the...
.
Distribution
The Redknife Formation occurs in outcrops in the southern Northwest TerritoriesNorthwest 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 in the sub-surface 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...
, also reaching into 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...
. The maximum thickness of the upper shales is 79 feet (24.1 m), and the lower carbonates are up to 15 feet (4.6 m). The Jean Marie Member is found in outcrops south of the Mackenzie River
Mackenzie River
The Mackenzie River is the largest river system in Canada. It flows through a vast, isolated region of forest and tundra entirely within the country's Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories...
between Kakisa
Kakisa, Northwest Territories
Kakisa is a "Designated Authority" in the South Slave Region of the Northwest Territories, Canada. The community is located on a lake of the same name, and is southeast of Fort Providence...
and Blackstone River. It grades westwards into the shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
facies
Facies
In geology, facies are a body of rock with specified characteristics. Ideally, a facies is a distinctive rock unit that forms under certain conditions of sedimentation, reflecting a particular process or environment....
of the Fort Simpson Formation
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 by A.E...
. East of the Peace River Arch it turns into the carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
s of the Kakisa Formation
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 River by H.R. Belyea and D.J...
.
Relationship to other units
The Redknife Formation is conformly overlain by the Kakisa FormationKakisa 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 River by H.R. Belyea and D.J...
and overlies the Tathlina Formation in northern Alberta
Northern Alberta
Northern Alberta is a region located in the Canadian province of Alberta.Its primary industry is oil and gas, with large heavy oil reserves being exploited at the Athabasca Oil Sands and Wabasca Area in the east of the region...
and the Fort Simpson Formation
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 by A.E...
in 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 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...
. The Fort Simpson Formation replaces the Redknife Formation to the west. The Redknife Formation can be correlated with the Nisku Formation and upper part of the Ireton Formation in central Alberta
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...
.
Subdivisions
The Jean Marie Member is designated as the lower part of the Redknife Formation where it is represented by massive limestoneLimestone
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....
or silty carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
s. The Jean Marie Member was deposited during the Frasnian
Frasnian
The Frasnian is one of two faunal stages in the Late Devonian epoch. It lasted from 385.3 ± 2.6 million years ago to 374.5 ± 2.6 million years ago. It was preceded by the Givetian stage and followed by the Famennian stage...
age. It is named for the Jean Marie River
Jean Marie River, Northwest Territories
Jean Marie River is a "Designated Authority" in the Dehcho Region of the Northwest Territories, Canada. The community is located on the Jean Marie River where it joins the Mackenzie River...
.