Montney Formation
Encyclopedia
The Montney 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 Middle Triassic
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between 245 ± 1.5 Ma and 228 ± 2 Ma...

 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...

 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 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...

.

It takes the name from the hamlet of Montney
Montney, British Columbia
Montney is an unincorporated locality located in British Columbia about north of Fort St. John, near Beatton Provincial Park.It lies at an elevation of , along the BC Rail tracks....

 and was first described in Texaco
Texaco
Texaco is the name of an American oil retail brand. Its flagship product is its fuel "Texaco with Techron". It also owns the Havoline motor oil brand....

's Buick Creek No. 7 well by J.H. Armitage in 1962. The well was drilled 41 kilometres (25.5 mi) north of Fort St. John
Fort St. John, British Columbia
The City of Fort St. John is a city in northeastern British Columbia, Canada. A member municipality of the Peace River Regional District, the city covers an area of about 22 km² with 22,000 residents . Located at Mile 47, it is one of the largest cities along the Alaska Highway. Originally...

, immediately east of the Alaska Highway
Alaska Highway
The Alaska Highway was constructed during World War II for the purpose of connecting the contiguous U.S. to Alaska through Canada. It begins at the junction with several Canadian highways in Dawson Creek, British Columbia and runs to Delta Junction, Alaska, via Whitehorse, Yukon...

.

Lithology

The formation is composed of 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...

 and dark grey 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...

, with 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....

 siltstone in the base and fine grained sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 towards the top. The 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....

 is 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...

y in the north and west of the extent (Fort St. John
Fort St. John, British Columbia
The City of Fort St. John is a city in northeastern British Columbia, Canada. A member municipality of the Peace River Regional District, the city covers an area of about 22 km² with 22,000 residents . Located at Mile 47, it is one of the largest cities along the Alaska Highway. Originally...

), silty
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...

 in the center (Dawson Creek
Dawson Creek, British Columbia
Dawson Creek is a small city in northeastern British Columbia, Canada. The municipality of had a population of 11,529 in 2009. Dawson Creek derives its name from the creek of the same name that runs through the community. The creek was named after George Mercer Dawson by a member of his land...

 and Pouce Coupe
Pouce Coupe, British Columbia
The Village of Pouce Coupe is a small town in northeastern British Columbia, Canada, and a member municipality of the Peace River Regional District. It was originally named 'Pouskapie's Prairie', after the name of the local native band chief...

 areas) and becomes coarser (sandy
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

) in western Alberta (Valleyview
Valleyview, Alberta
-History:*Late 1800s: The first visitors to the area arrived, seeking natives to exchange goods for furs. The trading was good and a Hudson’s Bay post was established on Sturgeon Lake...

 area).

Oil and gas production

Gas
Natural 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 Montney Formation in the Peace River Country
Peace River Country
The Peace River Country is an aspen parkland region around the Peace River in Canada. It spans from northwestern Alberta to the Rocky Mountains in northeastern British Columbia, where the region is also referred to as the Peace River Block.- Geography :The Peace River Country includes the...

 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 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...

, and 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 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...

. Horizontal drilling and extensive fracturing
Hydraulic fracturing
Considerable controversy surrounds the current implementation of hydraulic fracturing technology in the United States. Hydraulic fracturing, or fracking, is the process of utilizing pressurized water, or some other liquid, to fracture rock layers and release petroleum, natural gas, or other...

 process is necessary to flow the low permeability siltstone. Shale gas
Shale gas
Shale gas is natural gas produced from shale. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in the rest of the world...

 extraction emerged in the late 2000's in the distal facies of the formation's western extent.

Distribution

The Montney Formation reaches maximum thickness in the foothills of the northern Canadian Rockies
Canadian Rockies
The Canadian Rockies comprise the Canadian segment of the North American Rocky Mountains range. They are the eastern part of the Canadian Cordillera, extending from the Interior Plains of Alberta to the Rocky Mountain Trench of British Columbia. The southern end borders Idaho and Montana of the USA...

 at 280 metres (918.6 ft), and thins out towards the north up to the 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...

 area and towards the east to Peace River
Peace River, Alberta
Peace River is a town in northwestern Alberta, Canada, situated along the banks of the Peace River, at its confluence with the Smoky River, the Heart River and Pat's Creek. It is located northwest of Edmonton, and northeast of Grande Prairie, along Highway 2. The Peace River townsite is nearly ...

.

Relationship to other units

Montney Formation is 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...

 overlain by Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 or Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 beds such as the Doig Formation
Doig Formation
The Doig Formation is a stratigraphical unit of middle Triassic age in the Western Canadian Sedimentary Basin.It takes the name from Doig River, a tributary of the Beatton River, and was first described in the Texaco N.F.A. Buick Creek No. 7 well by J.H. Armitage in 1962...

 or Fernie Group and unconformably underlain by the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...

 or Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 strata such as the Belloy Formation
Belloy Formation
The Belloy Formation is a stratigraphical unit of Permian age in the Western Canadian Sedimentary Basin.It takes the name from the hamlet of Belloy, Alberta, and was first described in the Imperial Belloy 12-14-78-1W6M well by H.L...

.
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