The Foremost Formation is a

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostrati ...

unit of

Late 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'', the ...

(

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...

) age that underlies much of southern

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 ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. It was named for

outcrop An outcrop or rocky 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 ...

s in Chin Coulee near the town of ForemostGlass, 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. . and is known primarily for its dinosaur remains and other fossils.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. .

Geology

The Foremost Formation is the basal unit of the

Belly River Group The Belly River Group is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin. It takes the name from the Belly River, a tributary of the Oldman River in southern Alberta, and was first described in outcrop o ...

(called the

Judith River Group The Judith River Group is a group of geologic formations in western North America dating from the late Cretaceous and noted as a site for the extensive excavation of dinosaur fossils. The formation is named after the Judith River in Montana. The ...

in the United States). It gradationally overlies the marine shales of the Pakowki Formation. It consists of sediments that were eroded from the mountains to the west and carried northeastward by river systems, where they gradually prograded into the

Western Interior Seaway The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea, ...

.Eberth, D.A. 2005. The geology. In: Currie, P.J. and Koppelhus, E.B. (eds), Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Indiana University Press, Bloomington and Indianapolis, p. 54-82. . The bottom of the formation typically consists of a basal

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

unit overlain by the interbedded

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 elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...

seams, carbonaceous

shales Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...

and

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...

s of the Mackay coal zone. The center portion consists of interbedded sandstones, siltstones and mudstones, with minor carbonaceous shales. At the top are the interbedded coal seams, carbonaceous shales and mudstones of the Taber coal zone. The basal sandstones, which are commonly referred to as the Basal Belly River Sand, are a significant

hydrocarbon reservoir A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence ...

in some parts of Alberta. The Foremost Formation outcrops along the

Milk Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digestion, digest solid food. Immune factors and immune ...

Oldman Oldman may refer to: People * Oldman (king) (died 1687), King of the Miskito Nation *Albert Oldman (1883–1961), British boxer * C. B. Oldman (1894–1969), English bibliographer *Gary Oldman (born 1958), British actor * Hugh Oldman (1914–1988), ...

and

Bow River The Bow River is a river in Alberta, Canada. It begins within the Canadian Rocky Mountains and winds through the Alberta foothills onto the prairies, where it meets the Oldman River, the two then forming the South Saskatchewan River. These w ...

s. It is about thick near

Lethbridge Lethbridge ( ) is a city in the province of Alberta, Canada. With a population of 101,482 in its 2019 Alberta municipal censuses, 2019 municipal census, Lethbridge became the fourth Alberta city to surpass 100,000 people. The nearby Canadian ...

, thick near

Medicine Hat Medicine Hat is a city in Southern Alberta, southeast Alberta, Canada. It is located along the South Saskatchewan River. It is approximately east of Lethbridge and southeast of Calgary. This city and the adjacent Town of Redcliff, Alberta, ...

, and thick at

Dinosaur Provincial Park Dinosaur Provincial Park is a UNESCO World Heritage Site situated a two hour drive east of Calgary, Alberta, Canada; or , about a half-hour drive northeast of Brooks. The park is situated in the Red Deer River valley, which is noted for its strik ...

Paleobiota

Invertebrates

A variety of insects preserved in

amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Ma ...

such as the

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

s ''

Haidoterminus ''Haidoterminus'' is an extinct genus of ant in the Formicidae subfamily Haidomyrmecinae, and is one of only nine genera placed in this subfamily. The genus contains a single described species ''Haidoterminus cippus'' and is known from one Late ...

'' and ''

Boltonimecia ''Boltonimecia'' is an extinct genus of ant in the formicid subfamily Zigrasimeciinae. The genus contains a single described species, ''Boltonimecia canadensis'', and is known from a single Late Cretaceous fossil which was found in Canada. The ...

'' have been recovered from the Foremost Formation at a site near Grassy Lake, Alberta. The formation also includes a variety of freshwater, brackish water and marine

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

s such as ''

Ostrea ''Ostrea'' is a genus of edible oysters, marine bivalve mollusks in the family Ostreidae, the oysters. Fossil records This genus is very ancient. It is known in the fossil records from the Permian to the Quaternary (age range: from 259 to 0.0 ...

'' and ''

Corbula ''Corbula'' is a genus of very small saltwater clams, marine bivalve molluscs in the family Corbulidae, the basket clams.Gofas, S. (2010). Corbula Bruguière, 1797. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollusca databas ...

''.

Dinosaurs

The Foremost Formation has produced a lower diversity of documented dinosaurs than other Late Cretaceous units in the region unlike the

Dinosaur Park Formation The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 76. ...

Horseshoe Canyon Formation The Horseshoe Canyon Formation is a stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller. The Horseshoe Canyon Formation is part of the ...

, and

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 ...

. This is primarily due to their lower total fossil quantity and neglect from collectors who are hindered by the isolation and scarcity of well-exposed

s. The fossils are primarily isolated teeth recovered from vertebrate

microfossil A microfossil is a fossil that is generally between 0.001 mm and 1 mm in size, the visual study of which requires the use of light or electron microscopy. A fossil which can be studied with the naked eye or low-powered magnification, ...

sites." The vertebrate record of the Foremost Formation is best represented by vertebrate microfossil localities. "
Southern Alberta Dinosaur Research Group: Foremost Formation
.

Footnotes

References