The Peace River 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: lithostrati ...

unit of middle

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 M ...

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 takes the name from 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 in th ...

, 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. The descriptive name refers to the presence of "smouldering beds of coal in the riverbank" noted by the Cree Indians. It drains an area of . Fro ...

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

Lithology

The Peace River Formation consists of

greywacke Greywacke or graywacke (German ''grauwacke'', signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lit ...

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 elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...

, coarse to fine marine

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

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 minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

Hydrocarbon 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

Cadotte Member The Peace River Formation is a stratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin. It takes the name from the Peace River, and was first described on the banks of the river, downstream from the Smoky River conflue ...

in northern-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 ...

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; french: Région de la Rivière-de-la-paix) 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, ...

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 cent ...

south of

Clear Hills Clear Hills County is a municipal district in north western Alberta, Canada. It is located in Census Division 17. In 1950, the massive Chinchaga fire burned through much of the region. On January 1, 2006, the name was changed from ''Municip ...

, while the

and the

Harmon Member The Peace River Formation is a stratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin. It takes the name from the Peace River, and was first described on the banks of the river, downstream from the Smoky River conflue ...

occur in both

and north-eastern

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, ...

Physiography

The Peace River Lowland, a landform region in the Alberta Plateau. The landform region 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 straight-line distance from the northernmost part of western Canada, to New Mexico in ...

on both sides of the

, 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 great-circle distance, straight-line distance from the northernmost part of western Can ...

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 located in the north-west corner of Saskatchewan and the north-east corner of Alberta between 58° and 60° N in Canada. The lake ...

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). It follows the Neogene Period and spans from 2.58 million years ...

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 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

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 (place), 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 Vermilio ...

. 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), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

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 The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881. Lithology ...

shale and is conformably underlain by the

Spirit River Formation The Spirit River Formation is a stratigraphical 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. Li ...

. It is equivalent to the

Commotion Formation The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881. Lithology T ...

and to the Scatter Formation in the

Liard River The Liard River of the 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 southeast through British Co ...

area. It correlates to the

Buckinghorse Formation The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881. Lithology ...

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

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 The Fort St. John Group is a Stratigraphy, stratigraphic unit of Lower Cretaceous Geochronology, age in the Western Canadian Sedimentary Basin, Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia, Fo ...

. 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 bordere ...

, the Harmon Member can be correlated to the

Joli Fou Formation The Joli Fou Formation is a allostratigraphy, allostratigraphical unit of middle Albian Geochronology, age in the Western Canadian Sedimentary Basin. It takes the name from the Joli Fou Rapids on the Athabasca River, and was first described in an ...

, and the Cadotte Members with the

Viking Formation The Viking Formation is a stratigraphical 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. Lithol ...

References

{{WCSB, Northwest_Plains=yes Stratigraphy of Alberta Stratigraphy of British Columbia