The Smoky Group is a

stratigraphical 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

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone or something has been alive or has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

in the Western Canadian Sedimentary Basin. It takes the name from the

Smoky River The Smoky River is a river in western Alberta, Canada. It is a major tributary of the Peace River. The descriptive name refers to the presence of "smouldering beds of coal in the riverbank" noted by the Cree Indians. It drains an area of . Fro ...

, and was first described in outcrops along the banks of the Smoky River, Spirit River and

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 ...

s by George Mercer Dawson in 1881.Dawson, G.M., 1881. Report on the exploration from Port Simpson on the Pacific Coast to Edmonton on the North Saskatchewan River, Embracing a portion of the northern part of British Columbia and the Peace River Country, with Maps 150 and 152; Geological Survey of Canada, Report of Progress 1879-1880, Part B, p. 1-77.

Lithology

The Smoky Group is represented by

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

silty

shale 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, especial ...

with ironstone and bentonite streaks. Sandstone occurs at the base, and is transitional to the

Dunvegan Formation The Dunvegan Formation is a stratigraphical unit of Cenomanian age in the Western Canadian Sedimentary Basin. It takes the name from the settlement of Dunvegan, Alberta, and was first described in an outcrop on Peace River near Dunvegan by George ...

Hydrocarbon production

Gas is produced from 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 southern reaches of the Group, in central Alberta and northern Alberta.

Distribution

The Kaskapau Shale reaches 477m in the

area and thins towards the east in the

area. The Bad Heart Formation sandstone is up to 8m thick, while the

Puskwaskau Formation The Smoky Group is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin. It takes the name from the Smoky River, and was first described in outcrops along the banks of the Smoky River, Spirit River and Pouce Co ...

ranges from 200m in the Pouce Coupe Prairie to 123m in the Spirit River area. The entire group measures up to in the Pouce Coupe Prairie, and can reach in the

Canadian Rockies The Canadian Rockies (french: Rocheuses canadiennes) 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 ...

foothills of northeast British Columbia.

Relationship to other units

The Smoky Group is conformably and transgressively followed by the Wapiti Group and rests conformably on the

sandstone. The Cardium sandstone and Muskiki shale are replacing the upper parts of the

Kaskapau Formation The Kaskapau Formation is a geological formation in North America whose strata date back to the Late Cretaceous. The name derives from ''kaskapahtew'' (ᑲᐢᑲᐸᐦᑌᐤ), the Cree word for "smoky". It was first described on the banks of the ...

in the south-east of the distribution area. The entire group correlates with the Blackstone Formation,

and

Wapiabi Formation The Alberta Group is a stratigraphical unit of Cenomanian to early Campanian age in the Lewis overthrust in the Western Canadian Sedimentary Basin. It takes the name from the province of Alberta, and was first described in outcrops along the High ...

of the

Alberta Group The Alberta Group is a stratigraphical unit of Cenomanian to early Campanian age in the Lewis overthrust in the Western Canadian Sedimentary Basin. It takes the name from the province of Alberta, and was first described in outcrops along the Highw ...

in the southern foothills. The equivalent stratigraphic sequence in central Alberta consists of the

Lea Park Formation The Lea Park Formation is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin, Canada. It takes the name from the settlement of Lea Park, Alberta, located north-west of Lloydminster on the banks of the North ...

and the upper

Colorado Group Colorado is a geologic name applied to certain rocks of Cretaceous age in the North America, particularly in the western Great Plains. This name was originally applied to classify a group of specific marine formations of shale and chalk kn ...

, in north-eastern Alberta it correlates with

Labiche Formation The Labiche Formation is a stratigraphical unit of late Albian to Santonian age in the Western Canadian Sedimentary Basin. It takes the name from La Biche River, a tributary of the Athabasca River, and was first described in outcrop in the At ...

, and with the

Kotaneelee Formation The Kotaneelee Formation is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin. It takes the name from the Kotaneelee River, and was first described in outcrop in the river valley by C.O. Hage in 1945.Hage, ...

in the

Liard River The Liard River of the North American boreal forest flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows southeast through British Co ...

area.

Subdivisions

The Smoky Group has the following sub-divisions from top to bottom: The Kaskapau Formation is equivalent to the sum of Blackstone Formation,

and

Muskiki Formation The Muskiki Formation is a stratigraphical unit of Late Cretaceous age in the Western Canadian Sedimentary Basin. The formation is named after Muskiki Lake and Muskiki Creek, a tributary of the Cardinal River, and was first described in an outcrop ...

. File:Paskwaskau.JPG, Paskwaskau Shale File:Badheart Sand.JPG, Bad Heart Sandstone File:Kaskapau Shale.JPG, Kaskapau Shale

References

{{WCSB, Northwest_Plains=yes Stratigraphy of Alberta Stratigraphy of British Columbia Cretaceous Alberta Cretaceous British Columbia