Sentinel Butte Formation

The Sentinel Butte Formation is a geologic formation of Paleocene age in the Williston Basin of western North Dakota.^[1] It preserves significant assemblages of non-marine plant and animal fossils.

Sentinel Butte Formation
Stratigraphic range: Thanetian ~58–55 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Bentonite (Big Blue Bentonite) in the Sentinel Butte Formation (North Dakota)
Type	Formation
Unit of	Fort Union Formation
Underlies	Golden Valley Formation
Overlies	Bullion Creek Formation
Location
Region	North Dakota
Country	United States

See also

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