Willow Creek Formation

Last updated
Willow Creek Formation
Stratigraphic range: Late Cretaceous–Paleocene
Type Geological formation
Underlies Porcupine Hills Formation
Overlies St. Mary River Formation
Lithology
Primary Shale, sandstone
Location
Coordinates 49°46′19″N113°22′09″W / 49.77208°N 113.36920°W / 49.77208; -113.36920 (Willow Creek Formation)
Approximate paleocoordinates 57°36′N87°06′W / 57.6°N 87.1°W / 57.6; -87.1
RegionFlag of Alberta.svg  Alberta
Flag of Montana.svg  Montana
CountryFlag of Canada (Pantone).svg  Canada
Flag of the United States.svg  United States
Extent Western Canada Sedimentary Basin
Type section
Named forWillow Creek
Named by G.M. Dawson [1]
Year defined1883
Canada relief map 2.svg
Green-orange pog.svg
Willow Creek Formation (Canada)
Canada Alberta relief location map - transverse mercator proj.svg
Green-orange pog.svg
Willow Creek Formation (Alberta)

The Willow Creek Formation is a stratigraphic unit of Late Cretaceous to Early Paleocene age in the Western Canada Sedimentary Basin of southwestern Alberta. [2] It was first described by George Mercer Dawson in 1883 along the Willow Creek, a tributary of the Oldman River. Williams and Dyer defined the type section in 1930 at the mouth of Willow Creek, east of Fort Macleod. [3]

Contents

The formation straddles the Cretaceous-Paleogene (K-Pg) boundary, which divides it into an upper, Early Paleocene member and a lower, Late Cretaceous member. [4] Dinosaur remains are among the fossils that have been recovered from the Late Cretaceous portion. [5]

Lithology

The Willow Creek Formation is composed of non-marine varicolored shales, red beds and sandstones. The shales and red beds include calcite nodules and caliche deposits. The sandstones are soft, light grey, massively bedded and cross-bedded, with harder conglomeratic sandstones toward the base of the formation. [6]

Depositional environment

The sediments were eroded from the Canadian Cordillera, and were transported eastward by river systems and deposited in fluvial channel and floodplain environments. The caliche and red beds reflect deposition under arid to semi-arid climate conditions. This contrasts with the equivalent Scollard Formation north of the Bow River, which includes coal deposits indicative of a more humid environment.

Distribution

The Willow Creek Formation is present in southwestern Alberta, south of the Bow River, and extends a short distance into northern Montana. [7] It thins eastward from the foothills of the Canadian Rockies to its limit east of Vulcan, Alberta. Thicknesses exceeding 1000 meters have been reported. [6]

Relationship to other units

The Willow Creek Formation is overlain by the Porcupine Hills Formation, and underlain by the St. Mary River Formation. [4] It grades into the equivalent Scollard Formation south of the Bow River at about 50° 30'N latitude, and into the Coalspur Formation in the southern foothills. [7] The lower, Late Cretaceous member is correlated with the Frenchman Formation of Saskatchewan, and the upper, Early Paleocene member is correlated with the lower portion of the Ravenscrag Formation. [4] [8]

Vertebrate paleofauna

Ootaxa

Numerous eggshell fragments are known from the formation; over 85% of them belong to the ornithopod oogenus Spheroolithus . [9]

See also

Related Research Articles

<span class="mw-page-title-main">Two Medicine Formation</span> Geological formation in Montana, United States and Alberta, Canada

The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between 83.5 ± 0.7 Ma and 70.6 ± 3.4 Ma, during Campanian time. It crops out to the east of the Rocky Mountain Overthrust Belt, and the western portion of this formation is folded and faulted while the eastern part, which thins out into the Sweetgrass Arch, is mostly undeformed plains. Below the formation are the nearshore deposits of the Virgelle Sandstone, and above it is the marine Bearpaw Shale. Throughout the Campanian, the Two Medicine Formation was deposited between the western shoreline of the Late Cretaceous Interior Seaway and the eastward advancing margin of the Cordilleran Overthrust Belt. The Two Medicine Formation is mostly sandstone, deposited by rivers and deltas.

<span class="mw-page-title-main">Scollard Formation</span> Upper Cretaceous to lower Palaeocene stratigraphic unit of the Western Canada Sedimentary Basin

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 includes sediments that were deposited before, during, and after the Cretaceous-Paleogene (K-Pg) extinction event. It is significant for its fossil record, and it includes the economically important coal deposits of the Ardley coal zone.

The Frenchman Formation is stratigraphic unit of Late Cretaceous age in the Western Canada Sedimentary Basin. It is present in southern Saskatchewan and the Cypress Hills of southeastern Alberta. The formation was defined by G.M. Furnival in 1942 from observations of outcrops along the Frenchman River, between Ravenscrag and Highway 37. It contains the youngest of dinosaur genera, much like the Hell Creek Formation in the United States.

The Milk River Formation is a sandstone-dominated stratigraphic unit of the Western Canada Sedimentary Basin in southern Alberta, Canada. It was deposited in near-shore to coastal environments during Late Cretaceous time. Based on uranium-lead dating, palynology and stratigraphic relationships, deposition occurred between ~84.1 and 83.6 Ma.

The Belly River Group is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin.

<span class="mw-page-title-main">Foremost Formation</span> Geologic formation in Alberta, Canada

The Foremost Formation is a stratigraphic unit of Late Cretaceous (Campanian) age that underlies much of southern Alberta, Canada. It was named for outcrops in Chin Coulee near the town of Foremost and is known primarily for its dinosaur remains and other fossils.

The Wapiti Formation is a geological formation of the Western Canada Sedimentary Basin in northwestern Alberta, and northeastern British Columbia, Canada. Its deposition spanned the time interval from the lower Campanian through to the upper Maastrichtian, between approximately 80 and 68 Ma. It was named by G.M. Dawson in 1881, presumably for exposures along the lower part of the Wapiti River and downstream along the Smoky River in Alberta.

<span class="mw-page-title-main">St. Mary River Formation</span> Geologic formation in western Canada

The St. Mary River Formation is a geologic formation of Late Cretaceous age of the Western Canada Sedimentary Basin in southwestern Alberta and northwesternmost Montana. It was first described from outcrops along the St. Mary River by George Mercer Dawson in 1883, and it takes its name from the river.

The Denver Formation is a geological formation that is present within the central part of the Denver Basin that underlies the Denver, Colorado, area. It ranges in age from latest Cretaceous (Maastrichtian) to early Paleocene, and includes sediments that were deposited before, during and after the Cretaceous-Paleogene boundary event.

Gething Formation is a stratigraphic unit of Lower Cretaceous (Aptian) age in the Western Canada Sedimentary Basin. It is present in northeastern British Columbia and western Alberta, and includes economically important coal deposits.

<span class="mw-page-title-main">Paskapoo Formation</span> Stratigraphic unit in Western Canada

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. It was first described from outcrops along that river, near its confluence with the Red Deer River north of the city of Red Deer, by Joseph Tyrrell in 1887. It is important for its freshwater aquifers, its coal resources, and its fossil record, as well as having been the source of sandstone for the construction of fire-resistant buildings in Calgary during the early 1900s.

<span class="mw-page-title-main">Edmonton Group</span>

Within the earth science of geology, the Edmonton Group is a Late Cretaceous to early Paleocene stratigraphic unit of the Western Canada Sedimentary Basin in the central Alberta plains. It was first described as the Edmonton Formation by Joseph Burr Tyrrell in 1887 based on outcrops along the North Saskatchewan River in and near the city of Edmonton. E.J.W. Irish later elevated the formation to group status and it was subdivided into four separate formations. In ascending order, they are the Horseshoe Canyon, Whitemud, Battle and Scollard Formations. The Cretaceous-Paleogene boundary occurs within the Scollard Formation, based on dinosaurian and microfloral evidence, as well as the presence of the terminal Cretaceous iridium anomaly.

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 Frenchman River by N.B. Davis in 1918.

The Porcupine Hills Formation is a stratigraphic unit of middle to late Paleocene age in the Western Canada Sedimentary Basin. It takes its name from the Porcupine Hills of southwestern Alberta, and was first described in outcrop by George Mercer Dawson in 1883.

Continuoolithus is an oogenus of dinosaur egg found in the late Cretaceous of North America. It is most commonly known from the late Campanian of Alberta and Montana, but specimens have also been found dating to the older Santonian and the younger Maastrichtian. It was laid by an unknown type of theropod. These small eggs are similar to the eggs of oviraptorid dinosaurs, but have a distinctive type of ornamentation.

The Coalspur Formation is an Upper Cretaceous to lower Palaeocene stratigraphic unit of the Western Canada Sedimentary Basin in the foothills of southwestern Alberta. Its deposition spanned the time interval from latest Cretaceous (Maastrichtian) 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 deposits of the Coalspur Coal Zone, as well as nonmarine plant and animal fossils.

The Blairmore Group, originally named the Blairmore Formation, is a geologic unit of Early Cretaceous age in the Western Canada Sedimentary Basin that is present in southwestern Alberta and southeastern British Columbia. It is subdivided into four formations: Cadomin Formation, Gladstone, Beaver Mines and Ma Butte, all of which are defined by type sections, most of which contain plant fossils. In some areas the Blairmore contains significant reservoirs of natural gas.

The Battle Formation is a geologic formation of Late Cretaceous (Maastrichtian) age in the Western Canada Sedimentary Basin. It is present throughout much of the central Alberta plains, where it is an important stratigraphic marker in the nonmarine Upper Cretaceous sequence. It was formally named by G.M. Furnival in 1942 and given formation status by E.J.W. Irish in 1970.

The Gladstone Formation is a stratigraphic unit of Early Cretaceous (Aptian) age in the Western Canada Sedimentary Basin. It is present in the foothills of southwestern Alberta and is named for outcrops along Gladstone Creek, a tributary of the Castle River south of the Crowsnest Pass.

The Ma Butte Formation is a stratigraphic unit of Early Cretaceous (Albian) age in the Western Canada Sedimentary Basin. It was named for Ma Butte, a mountain north of Coleman, Alberta, by J.R. McLean in 1980. It is present in the foothills of southwestern Alberta and it contains plant fossils.

References

  1. ↑ Dawson, G.M., 1883. Preliminary report on the geology of the Bow and Belly River region, Northwest Territory, with special reference to the coal deposits. Geological Survey of Canada, Report of Progress for 1880-81-82, Part B.
  2. ↑ Lexicon of Canadian Geologic Units. "Willow Creek Formation" . Retrieved 2010-01-01.
  3. ↑ Williams, M.Y. and Dyer, W.S., 1930. Geology of southern Alberta and southwestern Saskatchewan; Geological Survey of Canada, Memoir 163.
  4. 1 2 3 Mossop, G.D. and Shetsen, I., (compilers), Canadian Society of Petroleum Geologists (1994). "The Geological Atlas of the Western Canada Sedimentary Basin, Chapter 24: Upper Cretaceous and Tertiary strata of the Western Canada Sedimentary Basin" . Retrieved 2013-08-01.{{cite web}}: CS1 maint: multiple names: authors list (link)
  5. ↑ Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. ISBN   0-520-24209-2.
  6. 1 2 Glass, D.J., editor, 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada. Canadian Society of Petroleum Geologists, Calgary, Alberta,1423 p. on CD-ROM, ISBN   0-920230-23-7.
  7. 1 2 Prior, G. J., Hathaway, B., Glombick, P.M., Pana, D.I., Banks, C.J., Hay, D.C., Schneider, C.L., Grobe, M., Elgr, R., and Weiss, J.A. (2013). "Bedrock Geology of Alberta. Alberta Geological Survey, Map 600" . Retrieved 2013-08-13.{{cite web}}: CS1 maint: multiple names: authors list (link)
  8. ↑ Alberta Geological Survey, 2013. "Alberta Table of Formations; Alberta Energy Regulator" (PDF). Retrieved 2016-06-20.
  9. ↑ Zelenitsky, Darla K.; Therrien, François; Tanaka, Kohei; Currie, Phillip J.; DeBuhr, Christopher L. (2017). "Latest Cretaceous eggshell assemblage from the Willow Creek Formation (upper Maastrichtian – lower Paleocene) of Alberta, Canada, reveals higher dinosaur diversity than represented by skeletal remains". Canadian Journal of Earth Sciences. 54 (2): 134–140. Bibcode:2017CaJES..54..134Z. doi:10.1139/cjes-2016-0080. hdl: 1807/75326 .
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.