The Peace River Formation is a

stratigraphic unit A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features ( facies) that characteriz ...

of middle

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone has been alive or something 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 Canada 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 b ...

. It takes the name from the

Peace River 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 joins the Athabasca River in the Peace-Athabasca Delta to form the ...

, and was first described on the banks of the river, downstream from the

Smoky River The Smoky River is a river in western Alberta, Canada. It is a major tributary of the Peace River (Canada), Peace River. The name refers to the presence of "smouldering beds of coal in the riverbank" noted by the Cree people, an Indigenous peop ...

confluence to the mouth of the Notikewin River by McConnell in 1893.

Lithology

The Peace River Formation consists of

greywacke Greywacke or graywacke ( ) is a variety of sandstone generally characterized by its hardness (6–7 on Mohs scale), dark color, and Sorting (sediment), poorly sorted angular grains of quartz, feldspar, and small rock fragments or sand-size Lith ...

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

, coarse to fine marine

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and dark, fissile, non-calcareous

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

Hydrocarbon production

Gas Gas is a state of matter that has neither a fixed volume nor a fixed shape and is a compressible fluid. A ''pure gas'' is made up of individual atoms (e.g. a noble gas like neon) or molecules of either a single type of atom ( elements such as ...

is produced from the Cadotte Member in northern-western

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

Distribution

The Peace River Formation is thick on average. The formation has different extents at different stages, with the Paddy Member present only in the

Peace River Country The Peace River Country (or Peace Country; ) is an aspen parkland region centring on the Peace River in Canada. It extends from northwestern Alberta to the Rocky Mountains in northeastern British Columbia, where a certain portion of the region i ...

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 ...

south of Clear Hills, while the Cadotte Member and the Harmon Member occur in both

and north-eastern

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

Physiography

The Peace River Lowland, a landform region in the

Alberta Plateau The Alberta Plateau is a flat and gently rolling upland in Northern Alberta and in the northeastern corner of British Columbia, Canada. It ranges in elevation from about and lies in the middle of the Interior Plains, one of seven physiographic r ...

, is a gently rolling lowland without clearly defined outer boundaries extending east of the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

on both sides of the

and sloping downward to the north and east. The higher hills in the foothills east of the

Rockies The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of Western Canada, to New Mexico in ...

in northeastern

have elevations of about 1000 m and the plains west of

Lake Athabasca Lake Athabasca ( ; French: ''lac Athabasca''; from Woods Cree: , " herethere are plants one after another") is in the north-west corner of Saskatchewan and the north-east corner of Alberta between 58° and 60° N in Canada. The lake is ...

are about 300 m above sea level. The lowland's

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

sediments of the former lake bottom of Glacial Lake Peace are underlain by Upper and Lower

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

sedimentary rocks mainly shales of the Shaftesbury formation and sandstones of the Dunvegan and Peace River formations. The

and its immediate tributaries have incised almost 200 meters into the sediments and into the Cretaceous bedrock in the western section but only about 70 meters in the east side further north around

Fort Vermilion Fort Vermilion is a hamlet on the Peace River in northern Alberta, Canada, within Mackenzie County. Established in 1788, Fort Vermilion shares the title of oldest European settlement in Alberta with Fort Chipewyan. Fort Vermilion contains many ...

. On the basis of topography and landscape pattern, the area may be subdivided into four local physiographic units: the Peace River Lowland, Otter Lakes Upland, Utikuma Lake Upland, and Clear Hills Upland. The Peace River Lowland is located in the central part of the area and is dissected by the

. The Otter Lakes Upland in the northeast is a southern extension of the Buffalo Head Hills. It has a rugged

moraine A moraine is any accumulation of unconsolidated debris (regolith and Rock (geology), rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a gla ...

topography with steep slopes and isolated hills. Elevations above sea level range from to . The Utikuma Lake Upland in the southeast also ranges from to . The Clear Hills Upland in the west ranges from to .

Relationship to other units

The Peace River Formation is a sub-division of the Fort St. John Group. It is conformably overlain by the Shaftesbury Formation shale and is conformably underlain by the

Spirit River Formation The Spirit River Formation is a stratigraphic unit of middle Albian age in the Western Canadian Sedimentary Basin. It takes the name from the Spirit River, and was first described in Imperial Oil Spirit River No. 1 well by Badgley in 1952. Litho ...

. It is equivalent to the Commotion Formation in

and to the Scatter Formation in the

Liard River The Liard River of the Boreal forest of Canada, North American boreal forest flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows sout ...

area. It correlates to the Buckinghorse Formation in north-eastern British Columbia.

Subdivisions

The Peace River Formation is composed of the following subdivisions from base to top: The Harmon Member correlates with the Hulcross Shale of the Commotion Formation in

and the shale member of the Scatter Formation in the

area. The Cadotte Member correlates with the lower part of the Boulder Creek Member of the Commotion Formation and to the sum of the sandy member of the Scatter Formation and the base of the Lepine Formation. In eastern and

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 bordered ...

, the Harmon Member can be correlated to the Joli Fou Formation, and the Cadotte Members with the

Viking Formation The Viking Formation is a stratigraphic unit of Cretaceous age in the Western Canadian Sedimentary Basin. It takes the name from the town of Viking, Alberta, and was first described in the Viking-Kinsella oil field by Dowling in 1919. Lithology ...

References

{{WCSB, Northwest_Plains=yes Geologic formations of Alberta Geologic formations of British Columbia Cretaceous Alberta Cretaceous British Columbia Sandstone formations of Canada Shale formations of Canada Coal formations Western Canadian Sedimentary Basin