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{{short description|Geologic formation in Canada}}
{{Infobox Rockunit
| name = Smoky Group
| image = Pouce Coupe River.JPG
| imagesize = 200px
| caption = Kaskapau Shale exposed along the [[Pouce Coupe River]]
| type = [[Geological group]]
| age = {{fossil range|Late Cretaceous|Late Cretaceous|[[Late Cretaceous]]}}
| period = Late Cretaceous
| prilithology = [[Shale]], [[sandstone]], [[siltstone]]
| otherlithology =
| namedfor = [[Smoky River]]
| namedby = [[George Mercer Dawson]], 1881.
| region = [[Alberta]], [[British Columbia]]
| country = Canada
| coordinates =
| unitof =
| subunits = [[Puskwaskau Formation]]<br>[[Bad Heart Formation]]<br>[[Kaskapau Formation]]
| underlies = [[Wapiti Group]]
| overlies = [[Dunvegan Formation]]
| thickness = up to {{convert|1100|ft|m|-1}}<ref name=lexicon>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:013975|title=Smoky Group|author=[[Lexicon of Canadian Geologic Units]] |accessdate=2009-02-11}}</ref>
| extent =
| area =
| map =
| map_caption =
}}
The '''Smoky Group''' is a [[stratigraphic unit]] of Late Cretaceous [[Geochronology|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 Coupe River]]s by [[George Mercer Dawson]] in 1881.<ref>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.</ref>

==Lithology==
The Smoky Group is represented by [[Marine (ocean)|marine]] silty [[shale]] with [[ironstone]] and [[bentonite]] streaks. [[Sandstone]] occurs at the base and is transitional to the [[Dunvegan Formation]].<ref name=lexicon/>

===Hydrocarbon production===

[[Natural gas|Gas]] is produced from the [[Cardium Formation]] in the southern reaches of the Group, in [[central Alberta]] and [[northern Alberta]].

==Distribution==
The Kaskapau Shale reaches 477m in the [[Pouce Coupe River]] area and thins towards the east in the [[Smoky River]] area. The [[Bad Heart Formation]] sandstone is up to 8m thick, while the [[Puskwaskau Formation]] ranges from 200m in the Pouce Coupe Prairie to 123m in the [[Spirit River, Alberta|Spirit River]] area. The entire group measures up to {{convert|677|m|ft|-1|abbr=on}} in the Pouce Coupe Prairie and can reach {{convert|1100|m|ft|-1|abbr=on}} in the [[Canadian Rockies]] foothills of northeast [[British Columbia]].<ref name=lexicon/>

==Relationship to other units==
The Smoky Group is conformably and [[transgression (geology)|transgressively]] followed by the [[Wapiti Group]] and rests conformably on the [[Dunvegan Formation]] sandstone. The [[Cardium Formation|Cardium]] sandstone and [[Muskiki Formation|Muskiki]] shale are replacing the upper parts of the [[Kaskapau Formation]] in the south-east of the distribution area. The entire group correlates with the [[Blackstone Formation, Canada|Blackstone Formation]], [[Cardium Formation]] and [[Wapiabi Formation]] of the [[Alberta Group]] in the southern foothills. The equivalent stratigraphic sequence in [[central Alberta]] consists of the [[Lea Park Formation]] and the upper [[Colorado Group]], in north-eastern Alberta it correlates with [[Labiche Formation]], and with the [[Kotaneelee Formation]] in the [[Liard River]] area.<ref name=lexicon/>

===Subdivisions===
The Smoky Group has the following sub-divisions from top to bottom:
{|class="wikitable"
|-
! [[Geological unit|Sub-unit]] !! [[Geochronology|Age]] !! Lithology !! Max.<br>Thickness !! Reference
|-
|[[Puskwaskau Formation]] || [[Santonian]] || dark [[marine (ocean)|marine]] [[shale]], [[siltstone]] beds || {{convert|200|m|ft|-1|abbr=on}}
|<ref>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:012285|title=Puskwaskau Formation|author=[[Lexicon of Canadian Geologic Units]] |accessdate=2009-02-11}}</ref>
|-
|[[Bad Heart Formation]] || [[Coniacian]] || medium to coarse grained [[marine (ocean)|marine]] [[sandstone]] || {{convert|8|m|ft|-1|abbr=on}}
|<ref>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:000656|title=Bad Heart Formation|author=[[Lexicon of Canadian Geologic Units]] |accessdate=2009-02-11}}</ref>
|-
|[[Kaskapau Formation]] || [[Turonian]] to [[Coniacian]] || dark, fissile [[shale]] || {{convert|900|m|ft|-1|abbr=on}}
|<ref name=Kaskapau>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:007398|archive-url=https://archive.today/20130111221415/http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:007398|url-status=dead|archive-date=2013-01-11|title=Kaskapau Formation|author=[[Lexicon of Canadian Geologic Units]]|accessdate=2009-02-11}}</ref>
|-
|colspan="5" align="center"|Basal sandstone tongues
|-
| [[Howard Creek Member]] || late [[Cenomanian]] || fine to medium grained [[glauconite|glauconitic]] [[sandstone]] || {{convert|4|m|ft|-1|abbr=on}} || <ref>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:006740|title=Howard Creek Member|author=[[Lexicon of Canadian Geologic Units]] |accessdate=2009-02-11}}</ref>
|-
| [[Doe Creek Member]] || [[Cenomanian]] || fine grained [[sandstone]] || {{convert|25|m|ft|-1|abbr=on}} || <ref>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:004066|title=Doe Creek Member|author=[[Lexicon of Canadian Geologic Units]] |accessdate=2009-02-11}}</ref>
|-
| [[Pouce Coupe Member]] || [[Cenomanian]] || massive, fine grained [[sandstone]] || {{convert|9|m|ft|-1|abbr=on}} || <ref>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:012150 |title=Pouce Coupe Member|author=[[Lexicon of Canadian Geologic Units]] |accessdate=2009-02-11}}</ref>
|-
|}
The Kaskapau Formation is equivalent to the sum of [[Blackstone Formation, Canada|Blackstone Formation]], [[Cardium Formation]] and [[Muskiki Formation]].<ref name=Kaskapau/>
<gallery>
File:Paskwaskau.JPG|Paskwaskau Shale
File:Badheart Sand.JPG|Bad Heart Sandstone
File:Kaskapau Shale.JPG|Kaskapau Shale

</gallery>

==References==
{{reflist}}

{{WCSB|Northwest_Plains=yes}}

[[Category:Geologic groups of Alberta]]
[[Category:Geologic groups of British Columbia]]
[[Category:Cretaceous Alberta]]
[[Category:Cretaceous British Columbia]]
[[Category:Shale groups of Canada]]
[[Category:Sandstone groups of Canada]]
[[Category:Siltstone groups]]

Smoky Group - Revision history

imported>The Space Enthusiast at 23:25, 25 June 2025