Wabamun Formation
Encyclopedia
The Wabamun Formation is a stratigraphical
unit of Famennian
age
in the Western Canadian Sedimentary Basin
.
It takes the name from Wabamun Lake
, and was first described in the Anglo Canadian Wabamun Lake No. 1 well (located between the Wabamun Lake and the North Saskatchewan River
) by Imperial Oil
in 1950.
and calcareous dolomite
with anhydrite
interbeds.
Halite
and anhydrite
are present at the base of the formation in the Stettler
region. It is composed entirely of limestone in north-western Alberta. Secondary pyrite
is found at the top of the formation.
reserve
of 7.2 million m³, with 3.2 million m³ already produced as of 2008. Gas
reserves totaled 102.8 million m³, with 53.5 million m³ already produced.
. It thins out and wedges towards the east, and thickens towards the Canadian Rockies
foothills.
overlain by the Exshaw Formation
in southern Alberta, by the Blairmore Group in western Alberta and by the Mannville Group
in eastern Alberta. It rests conformably on the Graminia Formation siltstone
of the Winterburn Group
.
In the Calgary area, the formation is divided into a lower and an upper part separated by the porous dolomitic Crossfield Member.
It is equivalent to the Three Forks Formation in Montana
, the Palliser Formation
in the Canadian Rockies
, the sum of the Kotcho Formation
and Tetcho Formation
in northeastern British Columbia
.
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 Famennian
Famennian
The Famennian is one of two faunal stages in the Late Devonian epoch. It lasted from 374.5 ± 2.6 million years ago to 359.2 ± 2.5 million years ago. It was preceded by the Frasnian stage and followed by the Tournaisian stage and is named after Famenne, a natural region in southern Belgium.It was...
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 Wabamun Lake
Wabamun Lake
Wabamun Lake is one of the most heavily used lakes in Alberta, Canada. It lies west of Edmonton, Alberta. It is long and narrow, covers and is 11 meters deep at its deepest, with somewhat clear water....
, and was first described in the Anglo Canadian Wabamun Lake No. 1 well (located between the Wabamun Lake and the North Saskatchewan River
North Saskatchewan River
The North Saskatchewan River is a glacier-fed river that flows east from the Canadian Rockies to central Saskatchewan. It is one of two major rivers that join to make up the Saskatchewan River....
) by Imperial Oil
Imperial Oil
Imperial Oil Limited is Canada's largest petroleum company. The company is engaged in the exploration, production and sale of crude oil and natural gas. It is controlled by US based ExxonMobil, which owns 69.6% of its stock...
in 1950.
Lithology
The Wabamun Formation is composed of dolomitic limestoneLimestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
and calcareous dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....
with anhydrite
Anhydrite
Anhydrite is a mineral – anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from the...
interbeds.
Halite
Halite
Halite , commonly known as rock salt, is the mineral form of sodium chloride . Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on the amount and type of impurities...
and anhydrite
Anhydrite
Anhydrite is a mineral – anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from the...
are present at the base of the formation in the Stettler
Stettler, Alberta
Stettler is a town in Alberta, Canada. It is located east of Red Deer at the junction of Highway 12 and Highway 56. The town is located in the eastern region of central Alberta and nicknamed "The Heart of Alberta."- History :...
region. It is composed entirely of limestone in north-western Alberta. Secondary pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
is found at the top of the formation.
Hydrocarbon potential
The Wabamun Formation had an initial established recoverable oilPetroleum
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...
reserve
Oil reserves
The total estimated amount of oil in an oil reservoir, including both producible and non-producible oil, is called oil in place. However, because of reservoir characteristics and limitations in petroleum extraction technologies, only a fraction of this oil can be brought to the surface, and it is...
of 7.2 million m³, with 3.2 million m³ already produced as of 2008. 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...
reserves totaled 102.8 million m³, with 53.5 million m³ already produced.
Distribution
The Wabamun Formation reaches a maximum thickness of 240 metres (787.4 ft) in the sub-surface of central AlbertaCentral 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...
. It thins out and wedges towards the east, and thickens towards the 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...
foothills.
Relationship to other units
The Wabamun Formation is disconformablyUnconformity
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 the Exshaw Formation
Exshaw Formation
The Exshaw Formation is a stratigraphical unit of Mississippian age in the Western Canadian Sedimentary Basin.It takes the name from the hamlet of Exshaw, Alberta, and was first described in outcrops on the banks of Jura Creek, north of Exshaw by P.S. Warren in 1937. The formation is of late...
in southern Alberta, by the Blairmore Group in western Alberta and by the Mannville Group
Mannville Group
The Mannville Group is a stratigraphical unit of Cretaceous age in the Western Canadian Sedimentary Basin.It takes the name from the town of Mannville, Alberta, and was first described in the Northwest Mannville 1 well by A.W...
in eastern Alberta. It rests conformably on the Graminia Formation 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...
of the Winterburn Group
Winterburn Group
The Winterburn Group is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.It takes the name from Winterburn area located west of Edmonton, and was first described in well P.A. Pyrcz No...
.
In the Calgary area, the formation is divided into a lower and an upper part separated by the porous dolomitic Crossfield Member.
It is equivalent to the Three Forks Formation in Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
, the Palliser Formation
Palliser Formation
The Palliser Formation is a stratigraphical unit of Famennian age in the Western Canadian Sedimentary Basin. found in the ranges of the Canadian Rockies and foothills....
in the 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...
, the sum of the Kotcho Formation
Kotcho Formation
The Kotcho Formation is a stratigraphical unit of middle Famennian age in the Western Canadian Sedimentary Basin.It takes the name from Kotcho Lake, and was first described in the Imperial Island River No. 1 by H.R. Belyea and D.J...
and Tetcho Formation
Tetcho Formation
The Tetcho Formation is a stratigraphical unit of Famennian age in the Western Canadian Sedimentary Basin.It takes the name from Tetcho Lake, and was first described in the Imperial Island River No. 1 well The Tetcho Formation is a stratigraphical unit of Famennian age in the Western Canadian...
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...
.