Cadomin Formation
Encyclopedia
The Cadomin Formation is a stratigraphical
unit of early Cretaceous
age. It is part of the Western Canadian Sedimentary Basin
and is found in western Alberta
, Canada
.
It was named after the mining town of Cadomin, itself an acronym of "Canadian Dominion Mining".
and coarse grained sand
that are composed of chert
and quartzite
cemented with silica. Siltstone
and mudstone
may be present between conglomerate beds, and occasionally coal
is observed.
is produced from the Cadomin Formation in the Deep Basin of Western Alberta in the Hinton
-Grande Cache
-Grande Prairie as well as the Cutbank area in north-eastern British Columbia
.
. It has a thickness of 1 metres (3.3 ft) to 170 metres (557.7 ft). It occurs at the surface in the foothills of the Canadian Rockies
and in the sub-surface towards the east and north, the limit being an erosional escarpment
formed north and east of the foothills.
of the formation is Lower Cretaceous. It is part of the Bullhead Group
in north-eastern British Columbia
and of the Blairmore Group in Alberta.
The Cadomin Formation is gradually overlain by the Gladstone Formation and Gething Formation
. It overlays the Fernie
shales, the Nikanassin Formation
and the Kootenay Group, forming a regional angular un-conformity.
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 early 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...
age. It is part of 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...
and is found in 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...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
It was named after the mining town of Cadomin, itself an acronym of "Canadian Dominion Mining".
Lithology
The geological formation consists of conglomerateConglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...
and coarse grained sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
that are composed of chert
Chert
Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...
and quartzite
Quartzite
Quartzite is a hard metamorphic rock which was originally sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink...
cemented with silica. 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...
and mudstone
Mudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...
may be present between conglomerate beds, and occasionally 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...
is observed.
Hydrocarbon production
Natural 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 Cadomin Formation in the Deep Basin of Western Alberta in the Hinton
Hinton, Alberta
Hinton is a town in west-central Alberta, Canada.It is located in Yellowhead County, northeast of Jasper and about west of Alberta's capital city, Edmonton, at the intersection of Yellowhead and Bighorn Highway, in the Athabasca River valley.-History:...
-Grande Cache
Grande Cache, Alberta
Grande Cache is a town in west-central Alberta, Canada, located northwest of Hinton and west of Edmonton. It is located in the Municipal District of Greenview, between Highway 40 and the Smoky River, at the northern border of Alberta's Rockies...
-Grande Prairie as well as the Cutbank area in 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...
.
Distribution
The type locality is found near Cadomin, where the formation forms an outcropOutcrop
An 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 superficial deposits are covered by a mantle of soil and vegetation and cannot be...
. It has a thickness of 1 metres (3.3 ft) to 170 metres (557.7 ft). It occurs at the surface in the foothills of 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...
and in the sub-surface towards the east and north, the limit being an erosional escarpment
Escarpment
An escarpment is a steep slope or long cliff that occurs from erosion or faulting and separates two relatively level areas of differing elevations.-Description and variants:...
formed north and east of the foothills.
Stragtigraphy
The ageGeochronology
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...
of the formation is Lower Cretaceous. It is part of the Bullhead Group
Bullhead Group
Bullhead Group is a stratigraphical unit of Lower Cretaceous age in the Western Canadian Sedimentary Basin.It was first defined by F.H. McLearn in 1918.-Lithology:...
in 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...
and of the Blairmore Group in Alberta.
The Cadomin Formation is gradually overlain by the Gladstone Formation and Gething Formation
Gething Formation
Gething Formation is a stratigraphical unit of Lower Cretaceous age in the Western Canadian Sedimentary Basin.It was first described in the Peace River Canyon by F.H. McLearn in 1923. The canyon was partly inundated in 1968 by the Williston Lake after the construction of the W. A. C. Bennett Dam...
. It overlays the Fernie
Fernie Formation
The Fernie Formation is a stratigraphical unit of Jurassic age in the Western Canadian Sedimentary Basin. In some interpretation it has Group status.It takes the name from the town of Fernie, British Columbia, and was first defined by Leach in 1914....
shales, the Nikanassin Formation
Nikanassin Formation
The Nikanassin Formation is a stratigraphical unit of late Jurassic age. It is part of the Western Canadian Sedimentary Basin and is found in western Alberta, Canada....
and the Kootenay Group, forming a regional angular un-conformity.