The Scollard Formation is an
Upper Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cret ...
to lower
Palaeocene stratigraphic unit of the
Western Canada Sedimentary Basin in southwestern
Alberta
Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...
.
Its deposition spanned the time interval from
latest Cretaceous to early
Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
, 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
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 ...
, and it includes the economically important
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal i ...
deposits of the Ardley coal zone.
Lithology
The Scollard Formation consists primarily of sandstones and siltstones, interbedded with mudstones and, in the upper portion, coal seams, as well as minor amounts of
bentonite
Bentonite ( ) is an Absorption (chemistry), 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 swelli ...
.
The sediments were eroded from the
Canadian Cordillera, 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. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...
environments.
Stratigraphy
The Scollard is usually classified as the uppermost formation of the
Edmonton Group, although some early workers included it in the overlying
Paskapoo Formation.
It is subdivided into an upper, coal-bearing member that consists of the Ardley coal zone, and a lower member that lacks significant coal.
Neither member has been formally named.
Age

The K-Pg boundary occurs at the base of the lowermost seam of Ardley coal zone, based on dinosaurian and
microfloral evidence, as well as the presence of the terminal Cretaceous
iridium anomaly. The upper member is therefore of early
Danian
The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cretac ...
age, while the lower member is of latest
Maastrichtian
The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...
age.
Distribution
The Scollard Formation is present in the subsurface throughout much of southwestern Alberta,
and it outcrops extensively along the banks of the
Red Deer River
The Red Deer River is a river in Alberta and a small portion of Saskatchewan, Canada. It is a major tributary of the South Saskatchewan River and is part of the larger Saskatchewan / Nelson River, Nelson system that empties into Hudson Bay.
T ...
in the area of
Trochu.
Both the upper and lower members thin from west to east. Thicknesses for each member range from more than near the foothills of the
Canadian Rockies
The Canadian Rockies () or Canadian Rocky Mountains, comprising both the Alberta Rockies and the British Columbian Rockies, is the Canadian segment of the North American Rocky Mountains. It is the easternmost part of the Canadian Cordillera, w ...
to less than near the outcrops in south-central Alberta.
Relationship to other units
The Scollard Formation rests
disconformably on the Late Cretaceous
Battle Formation in the southwestern Alberta plains, on the
Wapiti Formation in the northwestern plains, and on the Brazeau Formation in the foothills. It is
unconformably overlain by the
Paskapoo Formation, and where the Paskapoo has been removed by erosion, the Scollard is exposed at surface or covered by
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...
sediments.
The Scollard grades into the
Willow Creek Formation in the southern Alberta plains and the
Coalspur Formation in the Alberta foothills. The Ardley coal zone in the upper portion is equivalent to the lower part of the Coalspur coal zone of the Coalspur Formation, and is correlated with the lower part of the
Ravenscrag Formation of southern Saskatchewan, which is also coal bearing.
The Late Cretaceous member is equivalent in age to the
Frenchman Formation
The Frenchman Formation is a stratigraphic unit of Late Cretaceous (late Maastrichtian) Geochronology, age in the Western Canadian Sedimentary Basin, Western Canada Sedimentary Basin. It is present in southern Saskatchewan and the Cypress Hills (C ...
of Saskatchewan, the
Hell Creek Formation
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The Formation (stratigraphy), formation s ...
of Montana, and the
Lance Formation
The Lance (Creek) Formation is a division of Late Cretaceous (dating to about 69–66 Ma) rocks in the western United States. Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the lates ...
of Wyoming .
Coal deposits

The coal seams of the Ardley coal zone attain thicknesses in excess of in some areas. The zone is present at shallow depths and, in places, exposed at surface, along a trend between
Red Deer
The red deer (''Cervus elaphus'') is one of the largest deer species. A male red deer is called a stag or Hart (deer), hart, and a female is called a doe or hind. The red deer inhabits most of Europe, the Caucasus Mountains region, Anatolia, Ir ...
and
Edmonton
Edmonton is the capital city of the Provinces and territories of Canada, Canadian province of Alberta. It is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Central Alberta ...
. The coal is typically of
sub-bituminous
Sub-bituminous coal is a lower grade of coal that contains 35–45% carbon. The properties of this type are between those of lignite, the lowest grade of coal, and those of bituminous coal, the second-highest grade of coal. Sub-bituminous coal ...
B to C rank, although more deeply buried Scollard coals farther to the west reach high-volatile
bituminous
Bitumen ( , ) is an immensely viscous constituent of petroleum. Depending on its exact composition, it can be a sticky, black liquid or an apparently solid mass that behaves as a liquid over very large time scales. In American English, the m ...
rank. The Ardley coal has been mined in the Red Deer area, and is currently being mined west of
Edmonton
Edmonton is the capital city of the Provinces and territories of Canada, Canadian province of Alberta. It is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Central Alberta ...
to fuel mine-mouth electric power generating stations.
Paleontology
The Scollard Formation preserves the remains of vertebrates, especially dinosaurs and, rarely, mammals, as well as a wide range of plant fossils. The Scollard strata span the K-Pg boundary, therefore the lower member of the Scollard provides a record of the last of the dinosaurs, while the upper member records the dawn of the Age of Mammals after the K-Pg extinction event.
Flora
Plant fossils from the upper, early Paleocene member of the Scollard Formation include species of the
fern
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...
s ''
Botrychium'', ''
Woodwardia'' and ''
Azolla''; the conifers ''
Metasequoia'' and ''
Glyptostrobus''; the
monocot
Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are flowering plants whose seeds contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but ...
''
Limnobiophyllum'' (a relative of
duckweeds), ''
Sabalites geneseensis'' (similar to ''
Serenoa repens
''Serenoa repens'', commonly known as saw palmetto, is a small palm, growing to a maximum height around .
Taxonomy
It is the sole species in the genus ''Serenoa''. The genus name honors American botanist Sereno Watson.
Distribution and ...
''); and the
dicots ''
Cercidiphyllum
''Cercidiphyllum'' is a genus containing two species of plants, both commonly called katsura. They are the sole members of the monotypic family (biology), family Cercidiphyllaceae. The genus is native plant, native to Japan and China and unrelate ...
'' and ''
Platanus
''Platanus'' ( ) is a genus consisting of a small number of tree species native to the Northern Hemisphere. They are the sole living members of the family Platanaceae.
All mature members of ''Platanus'' are tall, reaching in height. The type ...
.'' Leaf analysis of the Genesee flora estimated mean annual temperature at with a cold month mean temperature of . ''
Graminidites'', a
Grass
Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...
palynomorph occurs in the Maastrichtian Scollard Formation. The species, ''G. ulkapites'', occurs at the initiation of a
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...
climate in the area.
Vertebrates
Crocodylian
Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchian ...
''
Albertosuchus'',
acanthomorph fish ''
Lindoeichthys'' and unnamed
esocid fish are known.
Theropods
''
Ornithomimus'' remains have been unearthed here.
Two
caenagnathid taxa, a large-bodied one similar to ''
Caenagnathus'' and a small-bodied one similar to ''
Leptorhynchos'' have been found.
Ornithischians
Fossil remains of the
nodosaur ''
Edmontonia'' and the
chasmosaur ''
Torosaurus
''Torosaurus'' (meaning "perforated lizard", in reference to the large openings in its frill) is a genus of herbivorous Chasmosaurinae, chasmosaurine Ceratopsia, ceratopsian dinosaur that lived during the late Maastrichtian age of the Late Cret ...
'' have also been unearthed here and in the nearby areas.
See also
*
List of dinosaur-bearing rock formations
This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have been documented.
* List of stratigraphic units with dinosaur body fossils
* List of stratigraphic units with dinosaur trace fossils
** ...
References
Bibliography
* Ryan, M. J., and Russell, A. P., 2001. Dinosaurs of Alberta (exclusive of Aves): In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 279–297.
* Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. .
{{Western Canadian Sedimentary Basin, Central_Plains=yes
Maastrichtian Stage of North America
Cretaceous Alberta
Cretaceous–Paleogene boundary
Danian Stage
Paleogene Alberta
Sandstone formations of Canada
Siltstone formations of Canada
Shale formations of Canada
Coal formations
Coal in Canada
Fluvial deposits
Fossiliferous stratigraphic units of North America
Paleontology in Alberta
Western Canadian Sedimentary Basin