Arikaree Formation

{{Short description|Geological formation in midwestern US}} {{Infobox rockunit | name = Arikaree Formation | image = PawneeButtes 1900 USGS.jpg | caption = Arikaree Formation over Brule Formation (Pawnee Buttes, Colorado) | type = Formation / Group | age = <br/>late Oligocene to early<ref name= GeolexUnit />{{fossilrange|Miocene}} | period = Miocene | prilithology = Siltstone, Sandstone | otherlithology = Carbonate rock | namedfor = Arikara Indians<ref name= GeolexUnit /> | namedby = N. H. Darton<ref name= GeolexUnit /> | region = central High Plains<ref name= GeolexUnit /> | country = United States | coordinates = | unitof = | subunits = | underlies = unconsolidated sediment | overlies = Chadron Formation or Brule Formation | thickness = up to {{convert|426.5|ft|m|-1}} | extent = | area = | map = | map_caption = }}

The '''Arikaree Formation''', also '''Arikaree Group''' or '''Arikaree Sandstone''' is a geological unit in the central High Plains of the western United States. It preserves fossils dating to the late Oligocene to early Miocene.<ref name= GeolexUnit>{{cite web | title = Geologic Unit: Arikaree | series = Geolex — Unit Summary | work = National Geologic Database |publisher = United States Geological Survey | url = https://ngmdb.usgs.gov/Geolex/Units/Arikaree_6535.html | access-date = 2024-02-24 }}</ref>

==See also== {{Portal|Earth sciences|Paleontology}} * List of fossiliferous stratigraphic units in North Dakota * Paleontology in North Dakota

==References== {{Reflist}}

Category:Neogene geology of South Dakota Category:Neogene Montana Category:Paleogene geology of North Dakota Category:Neogene geology of Wyoming Category:Siltstone formations of the United States Category:Sandstone formations of the United States Category:Geologic formations of South Dakota Category:Geologic formations of Montana Category:Geologic formations of North Dakota Category:Geologic formations of Wyoming