Peace River Formation
Encyclopedia
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
confluence to the mouth of the Notikewin River by McConnell in 1893.
, coal
, coarse to fine marine sandstone
and dark, fissile, non-calcareous shale
.
is produced from the Cadotte Member in northern-western Alberta
.
in northern Alberta
south of Clear Hills
, while the Cadotte Member and the Harmon Member occur in both Alberta
and north-eastern British Columbia
.
on both sides of the Peace River
, sloping downward to the north and east. The higher hills in the foothills east of the Rockies
in northeastern British Columbia
have elevations of about 1000 m and the plains west of Lake Athabasca
are about 300 m above sea level. The lowland’s Quaternary
sediments of the former lake bottom of Glacial Lake Peace are underlain by Upper and Lower Cretaceous
sedimentary rocks mainly shales of the Shaftesbury formation and sandstones of the Dunvegan and Peace River formations. The Peace River
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
.
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 Peace River
. The Otter Lakes Upland in the northeast is a southern extension of the Buffalo Head Hills. It has a rugged moraine
topography with steep slopes and isolated hills. Elevations above sea level range from 1900 feet (579.1 m) to 2600 feet (792.5 m). The Utikuma Lake Upland in the southeast also ranges from 1900 feet (579.1 m) to 2700 feet (823 m). The Clear Hills Upland in the west ranges from 1900 feet (579.1 m) to 2700 feet (823 m).
. It is conformably overlain by the Shaftesbury Formation shale and is conformably underlain by the Spirit River Formation
.
It is equivalent to the Commotion Formation in British Columbia
and to the Scatter Formation in the Liard River
area. It correlates to the Buckinghorse Formation in north-eastern British Columbia.
The Harmon Member correlates with the Hulcross Shale of the Commotion Formation in British Columbia
and the shale member of the Scatter Formation in the Liard River
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
, the Harmon Member can be correlated to the Joli Fou Formation
, and the Cadotte Members with the Viking Formation
.
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 Albian
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 112.0 ± 1.0 Ma to 99.6 ± 0.9 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...
.
It takes the name from 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,...
, and was first described on the banks of the river, downstream from the Smoky River
Smoky River
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....
confluence to the mouth of the Notikewin River by McConnell in 1893.
Lithology
The Peace River Formation consists of greywackeGreywacke
Greywacke or Graywacke 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 lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found...
, coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
, coarse to fine marine 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,...
and dark, fissile, non-calcareous 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...
.
Hydrocarbon 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 Cadotte Member in northern-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...
.
Distribution
The Peace River Formation is 60 feet (18.3 m) thick on average. The formation has different extents at different stages, with the Paddy Member present only in the Peace River CountryPeace 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 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...
south of Clear Hills
Clear Hills County, Alberta
Clear Hills County is a municipal district in north western Alberta, Canada. It is located in Census Division 17.On Jan 01, 2006, the name was changed from Municipal District of Clear Hills No...
, while the Cadotte Member and the Harmon Member occur in both 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 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...
.
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 MountainsRocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
on both sides of 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,...
, sloping downward to the north and east. The higher hills in the foothills east of the Rockies
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
in northeastern 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...
have elevations of about 1000 m and the plains west of Lake Athabasca
Lake Athabasca
Lake Athabasca is located in the northwest corner of Saskatchewan and the northeast corner of Alberta between 58° and 60° N.-History:The name in the Dene language originally referred only to the large delta formed by the confluence the Athabasca River at the southwest corner of the lake...
are about 300 m above sea level. The lowland’s Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
sediments of the former lake bottom of Glacial Lake Peace are underlain by Upper and Lower 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...
sedimentary rocks mainly shales of the Shaftesbury formation and sandstones of the Dunvegan and Peace River formations. 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,...
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, Alberta
Fort Vermilion is a hamlet 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 modern amenities to serve its inhabitants as well as the surrounding rural...
.
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 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,...
. The Otter Lakes Upland in the northeast is a southern extension of the Buffalo Head Hills. It has a rugged moraine
Moraine
A moraine is any glacially formed accumulation of unconsolidated glacial debris which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past glacial maximum. This debris may have been plucked off a valley floor as a glacier advanced or it may have...
topography with steep slopes and isolated hills. Elevations above sea level range from 1900 feet (579.1 m) to 2600 feet (792.5 m). The Utikuma Lake Upland in the southeast also ranges from 1900 feet (579.1 m) to 2700 feet (823 m). The Clear Hills Upland in the west ranges from 1900 feet (579.1 m) to 2700 feet (823 m).
Relationship to other units
The Peace River Formation is a sub-division of the Fort St. John GroupFort St. John Group
The Fort St. John Group is a stratigraphical unit of Lower Cretaceous age in the Western Canadian 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:...
. It is conformably overlain by the Shaftesbury Formation shale and is conformably underlain by the Spirit River Formation
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...
.
It is equivalent to the Commotion Formation 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 to the Scatter Formation in the Liard River
Liard River
The Liard River 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 Columbia, marking the northern end of the Rocky Mountains and then curving northeast back...
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:| Sub-unit | 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... | Lithology | Max Thickness | Reference |
|---|---|---|---|---|
| Paddy Member | Early Cretaceous Early Cretaceous The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous... |
greywacke Greywacke Greywacke or Graywacke 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 lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found... , coal Coal Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure... |
40 feet (12.2 m) | |
| Cadotte Member | middle Albian 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 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma... |
coarse to fine marine 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,... |
52 feet (15.8 m) | |
| Harmon Member | middle Albian 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 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma... |
dark, fissile, non-calcareous 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... |
34 feet (10.4 m) | |
The Harmon Member correlates with the Hulcross Shale of the Commotion Formation 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 the shale member of the Scatter Formation in the Liard River
Liard River
The Liard River 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 Columbia, marking the northern end of the Rocky Mountains and then curving northeast back...
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
Central Alberta is a region located in the Canadian province of Alberta.Central Alberta is the most densely populated rural area in the province...
, the Harmon Member can be correlated to the Joli Fou Formation
Joli Fou Formation
The Joli Fou Formation is a stratigraphical unit of middle Albian 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 outcrop along the river, downstream from Joli Fou Rapids, by RTD Wickenden in...
, and the Cadotte Members with the Viking Formation
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.-Lithology:...
.