Arikaree Formation

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.^[1]

Arikaree Formation
Stratigraphic range: late Oligocene to early[1]Miocene PreꞒ Ꞓ O S D C P T J K Pg N
Arikaree Formation over Brule Formation (Pawnee Buttes, Colorado)
Type	Formation / Group
Underlies	unconsolidated sediment
Overlies	Chadron Formation or Brule Formation
Thickness	up to 426.5 feet (130 m)
Lithology
Primary	Siltstone, Sandstone
Other	Carbonate rock
Location
Region	central High Plains[1]
Country	United States
Type section
Named for	Arikara Indians[1]
Named by	N. H. Darton[1]

See also

• Earth sciences portal
• Paleontology portal

• List of fossiliferous stratigraphic units in North Dakota
• Paleontology in North Dakota