The Kaskapau Formation is a geological formation in North America whose strata date back to the

Late 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 ''cre ...

. The name derives from ''kaskapahtew'' (ᑲᐢᑲᐸᐦᑌᐤ), the

Cree The Cree, or nehinaw (, ), are a Indigenous peoples of the Americas, North American Indigenous people, numbering more than 350,000 in Canada, where they form one of the country's largest First Nations in Canada, First Nations. They live prim ...

word for "smoky". It was first described on the banks of the

Smoky River The Smoky River is a river in western Alberta, Canada. It is a major tributary of the Peace River (Canada), Peace River. The name refers to the presence of "smouldering beds of coal in the riverbank" noted by the Cree people, an Indigenous peop ...

, close to the confluence with the Puskwaskau River by F.H. McLearn in 1926.

Geographical distribution

The formation is thick in the

Peace River The Peace River () is a river in Canada that originates in the Rocky Mountains of northern British Columbia and flows to the northeast through northern Alberta. The Peace River joins the Athabasca River in the Peace-Athabasca Delta to form the ...

and

area, and thickens up to in the foothills of the

Northern Rocky Mountains The Northern Rocky Mountains, usually referred to as the Northern Rockies, are a subdivision of the Canadian Rockies comprising the northern half of the Canadian segment of the Rocky Mountains. While their northward limit is easily defined as th ...

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

. It is exposed along the Peace River near

Dunvegan Dunvegan () is a village on the Isle of Skye in Scotland. It is famous for Dunvegan Castle, seat of the chiefs of Clan MacLeod. Dunvegan is within the parish of Duirinish, Skye, Duirinish. In 2011, it had a population of 386. Name In ''The Nors ...

, as well as in the Smoky River area. The formation is part of the Smoky River Group, and is conformably overlain by the Bad Heart Formation in the western area, and

unconformably An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...

by the

Cardium Formation The Cardium Formation is a stratigraphic unit of Late Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the fossilized heart-shaped cockle shells in the family Cardiidae (from Greek ''kardiā'', "heart") present. It ...

in the

Pouce Coupe River The Pouce Coupe River is a major tributary of the Peace River (Canada), Peace River in Alberta and British Columbia, Canada. Its name is officially spelled ''Pouce Coupé River'', but it is commonly written without the acute accent. Originating i ...

area. It is conformable underlain by the Dunvegan Formation. The Kaskapau Formation is equivalent to the Colorado Group shale in

central Alberta Central Alberta is a region located in the Canadian province of Alberta. Central Alberta is the most densely populated rural area in the province. Agriculture and energy are important to the area's economy. Geography Central Alberta is bordered ...

. It is equivalent to the upper Blackstone Formation, the

, and the Muskiki Formation in 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 ...

foothills in western

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 ...

Lithology

The Kaskapau Formation is represented mostly by dark grey

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

, with

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

tongues and lentils at the base ( Doe Creek Member, Pouce Coupe Member). Thin

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, produced during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to r ...

layers may occur in the British Columbia foothills.

Paleontology

Oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

fossils are encountered at the base of the formation, and

Inoceramus ''Inoceramus'' (Greek: translation "fibrous shell" for the fibrous structure of the mineral crystals in the shell) is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of th ...

fragments (such as ''I. labiatus'') are found throughout the entire stack.

Ammonite Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

s are also present in the sand beds, genus encountered include Dunveganoceras and

Watinoceras ''Watinoceras'' is a genus of Acanthoceratidae, acanthoceratid ammonite that lived during the early Turonian stage of the Late Cretaceous. Description Early whorls are compressed, finely ribbed with inner and outer ventrolateral and siphonal ...

in the lower part and

Scaphites ''Scaphites'' is a genus of heteromorph ammonites belonging to the Scaphitidae family. They were a widespread genus that thrived during the Late Cretaceous period. Morphology ''Scaphites'' generally have a chambered, boat-shaped shell. The ini ...

in the upper part. Microfauna include benthonic (and fewer

planktonic Plankton are the diverse collection of organisms that drift in water (or air) but are unable to actively propel themselves against currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they pro ...

)

foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

. An indeterminate hadrosaurid and a possible nodosaurid are known from Quality Creek.

References

{{WCSB, Northwest_Plains=yes Geologic formations of Alberta Geologic formations of British Columbia Upper Cretaceous Series of North America Cretaceous Alberta Cretaceous British Columbia Coniacian Stage Turonian Stage Shale formations