The Coalspur Formation is an

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

to lower Palaeocene

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 characterize ...

of the

Western Canada 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 ...

in the foothills of southwestern

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 ...

. Its deposition spanned the time interval from latest Cretaceous (

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

) to early Palaeocene, and it includes sediments that were deposited before, during, and after the Cretaceous-Paleogene (K-Pg) extinction event. It includes the economically important

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

deposits of the Coalspur Coal Zone, as well as nonmarine plant and animal

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

Lithology

The sediments of the Coalspur Formation were eroded from the

Canadian Cordillera The Pacific Cordillera, also known as the Western Cordillera or simply The Cordillera, is a top-level physiographic region of Canada, referring mainly to the extensive cordillera system in Western and Northwestern Canada that constitutes the northe ...

, and were transported eastward by river systems and deposited in fluvial channel and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

environments. The formation consists primarily of sandstones and siltstones, interbedded with mudstones and minor amounts of

bentonite Bentonite () is an absorbent swelling clay consisting mostly of montmorillonite (a type of smectite) which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has a considerably greater swelling capacity than Ca-m ...

. Thick coal seams are present locally in the upper portion of the formation, especially in the Alberta Coal Branch area southeast of

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 valle ...

. Near the Athabasca River the base consists primarily of conglomerate and is known as the Entrance Conglomerate.

Stratigraphy and age

The Coalspur Formation is part of the Saunders group. The K-Pg boundary has been identified within the formation at the base of the lowermost coal seam (the Mynheer seam), based on changes in the fossil

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...

assemblage and the presence of an

iridium anomaly The term iridium anomaly commonly refers to an unusual abundance of the chemical element iridium in a layer of rock strata at the Cretaceous–Paleogene (K–Pg) boundary. The unusually high concentration of a rare metal like iridium is often take ...

.Jerzykiewicz, T. and Sweet, A.R. 1986. The Cretaceous-Tertiary boundary, central Alberta foothills. In: Stratigraphy. Canadian Journal of Earth Sciences, vol. 23, p. 1356-1374. The boundary subdivides the Coalspur Formation into an upper member called the Coalspur coal zone which is of early Paleocene age, and an unnamed lower member of latest Cretaceous age.Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. .

Thickness and distribution

The Coalspur Formation is present in the Alberta foothills from south of the Wapiti River to the

North Saskatchewan River The North Saskatchewan River is a glacier-fed river that flows from the Canadian Rockies continental divide east to central Saskatchewan, where it joins with the South Saskatchewan River to make up the Saskatchewan River. Its water flows eventual ...

. The formation is estimated to reach thicknesses of up to about , and the Coalspur coal zone is about to thick.

Relationship to other units

The Coalspur Formation rests abruptly on the

Brazeau Formation The Brazeau Formation is a geologic formation in Alberta. It preserves fossils dating back to the Cretaceous period. See also * List of fossiliferous stratigraphic units in Alberta This is a list of fossiliferous stratigraphic units in Alberta ...

and is overlain abruptly by the

Paskapoo Formation The Paskapoo Formation is a stratigraphic unit of Middle to Late Paleocene age in the Western Canada Sedimentary Basin. The Paskapoo underlies much of southwestern Alberta, and takes the name from the Blindman River (''paskapoo'' means "blind ...

. It is equivalent to the

Scollard Formation The Scollard Formation is an Upper Cretaceous to lower Palaeocene stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. Its deposition spanned the time interval from latest Cretaceous to early Paleocene, and it inclu ...

of the west-central Alberta plains, the

Willow Creek Formation The Willow Creek Formation is a stratigraphic unit of Late Cretaceous to Early Paleocene age in the Western Canada Sedimentary Basin of southwestern Alberta. It was first described by George Mercer Dawson in 1883 along the Willow Creek, a tribut ...

in the southwestern plains, and part or all of the

Ravenscrag Formation The Ravenscrag Formation is a stratigraphic unit of early Paleocene age in the Western Canada Sedimentary Basin. It was named for the settlement of Ravenscrag, Saskatchewan, and was first described from outcrops at Ravenscrag Butte near the Fre ...

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North ...

. The base of the Coalspur coal zone is equivalent to the base of the Ardley coal zone, which is also floored on the K-Pg boundary bed.

Paleontology

Plant fossilsBell, W.A. 1949. Uppermost Cretaceous and Paleocene floras of western Canada. Geological Survey of Canada, Bulletin 13, 231 p. and mammal remainsFox, R.C., 1990. The succession of Paleocene mammals in western Canada. Geological Society of America, Special Paper 243, pp. 51-70. have been described from the Coalspur Formation, but although the lower part of the formation is of Late Cretaceous age, no dinosaur remains have yet been reported. Fossils reported from the Coalspur Formation:Diss Locality
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cre ...

.org * Batrachosauroididae ** '' Opisthotriton kayi'' * Mammals ** '' Neoplagiaulax cf. nanophus'' ** '' N. cf. nelsoni'' ** '' Simpsonictis cf. jaynanneae'' ** '' Aphronorus sp.'' ** '' Baiotomeus sp.'' ** '' Colpoclaenus sp.'' ** '' Mimetodon sp.'' ** '' Pararyctes sp.'' ** '' Parectypodus sp.'' ** '' Promioclaenus sp.'' ** '' Propalaeosinopa sp.'' ** '' Ptilodus sp.'' ** Condylarthra indet. ** Lipotyphla indet. ** Neoplagiaulacidae indet. ** Paromomyidae indet. ** Creodonta indet.

Resources

The Coalspur Formation includes seven major seams that range up to in thickness. The coal is of sub-bituminous B to C rank, with a low sulphur content. It is mined in the Alberta Coal Branch area and shipped to electric power generating stations in Canada and abroad.

References

External links

* {{cite web, title= Fossilworks: Gateway to the Paleobiology Database, author= ((Various Contributors to the Paleobiology Database)), url= http://www.fossilworks.org/cgi-bin/bridge.pl?action=home, access-date= 17 December 2021 Geologic formations of Canada Western Canadian Sedimentary Basin Paleogene Alberta Cretaceous Alberta Paleocene North America Cretaceous–Paleogene boundary Maastrichtian Stage of North America Danian Stage Sandstone formations Siltstone formations Shale formations Coal formations Coal in Canada Paleontology in Alberta