The Horn River Formation (also ''Horn River Shale'') is a

stratigraphic 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: lithostra ...

unit of Devonian (early

Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian The Frasnian is one of two faunal stages in the ...

to late

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 th ...

)

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 older ...

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 is a thick sequence of marine sediments that was first described in

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficia ...

on the banks of the

Horn River The Horn River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River. The river gives the name to the Horn River Formation, a shale deposit of the Western Canadian Sedimentary Basin. The Horn River ...

, a tributary of the Mackenzie River, in the Northwest Territories (at the time District of Mackenzie) by Whittaker in 1922, and it takes its name from that river. In 1963 it was redefined in the subsurface of the Fort Nelson area of

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

(well Fort Nelson a-95-J/94-J-10) by F.F. Gray and J.R. Kassube. It is significant for its

shale gas Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some ...

resources.

Lithology

The Horn River Formation is composed of dark

siliceous Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

and

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an ad ...

shale, and

argillaceous Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minerals ...

bituminous Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term ...

limestone.

Stratigraphy

The Horn River Formation is included in the Beaverhill Lake Group. It is subdivided into the following members, from top to base: * Muskwa Member: bituminous, mildly radioactive shale * Otter Park Member: grey calcareous shale * Evie Member: black silty limestone

Distribution

The Horn River Formation is present in the subsurface in northeastern British Columbia and extends to

Great Slave Lake Great Slave Lake (french: Grand lac des Esclaves), known traditionally as Tıdeè in Tłı̨chǫ Yatıì (Dogrib), Tinde’e in Wıìlıìdeh Yatii / Tetsǫ́t’ıné Yatıé (Dogrib / Chipewyan), Tu Nedhé in Dëne Sųłıné Yatıé (Chi ...

in the Northwest Territories, where it outcrops. It reaches a maximum thickness of in the subsurface of the Fort Nelson area.

Relationship to other units

The Horn River Formation is overlain by 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 ...

and underlain by the limestones of the Lonely Bay 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 prominent ridge at the confluence of the South Nahanni River and Liard River, and was first descr ...

or Pine Point Formation. It is equivalent to the Slave Point Formation. In the Northwest Territories it includes the Muskwa Formation, and the Waterways Member of the

Hay River Formation The Hay River Formation is a geologic formation in Northwest Territories. It preserves fossils dating back to the Devonian period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Art ...

. It includes the pinnacle

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock o ...

s of the Horn Plateau Formation.

Hydrocarbon production

Shale gas Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some ...

is present in the siliceous shales of all three members of the Horn River Formation in northeastern British Columbia, and it is produced in the Greater Sierra oil field north of Fort Nelson.

Horizontal drilling Directional drilling (or slant drilling) is the practice of drilling non-vertical bores. It can be broken down into four main groups: oilfield directional drilling, utility installation directional drilling, directional boring (horizontal dir ...

and

fracturing Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displa ...

techniques are used to extract the gas from the low permeability shales. The original-gas-in-place volumes are estimated to be up to 500 Tcf, making it the third largest North American natural gas accumulation discovered prior to 2010. Companies involved in the extraction of natural gas from the Horn River Shale include

Ovintiv Ovintiv Inc. is a hydrocarbon exploration and production company organized in Delaware and headquartered in Denver, United States. It was founded and headquartered in Calgary, Alberta, under its previous name Encana. It was the largest energy co ...

EOG Resources EOG Resources, Inc. is an American energy company engaged in hydrocarbon exploration. It is organized in Delaware and headquartered in the Heritage Plaza building in Houston, Texas. The company is ranked 186th on the Fortune 500 and 337th on t ...

, Stone Mountain Resources, ExxonMobil, Quicksilver Resources, and CNOOC Petroleum North America ULC. Horn River gas contains 10-12% , much higher than the 2–4.5% of conventional natural gas. If this gas is processed normally about 500 million tonnes of will be released into the atmosphere.

Hydraulic fracturing in Canada

Massive hydraulic fracturing has been widely used in

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 ...

since the late 1970s. The method is currently used in development of the Cardium, Duvernay, Montney and

Viking Vikings ; non, víkingr is the modern name given to seafaring people originally from Scandinavia (present-day Denmark, Norway and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded and se ...

formations in

, Bakken formation in

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

, Montney and Horn River formations in

References

{{Shale gas Shale formations Oil-bearing shales in Canada Natural gas fields in Canada Devonian British Columbia Devonian Northwest Territories Frasnian Stage Givetian Stage Stratigraphy of British Columbia Devonian System of North America