Type Formation Primary Slate Overlies Dakota Formation | Country United States Named for Fort Benton Underlies Niobrara Formation | |
Other Limestone, sandstone, bentonite Regions Montana, Wyoming, North Dakota, South Dakota, Colorado, Nebraska | ||
The Benton Shale is a geologic formation in Montana, Wyoming, North Dakota, South Dakota, Colorado and Nebraska. It preserves fossils dating back to the Cretaceous Period.
It derives its name from Fort Benton, a small city in Montana on the Upper Missouri River.
References
Benton Shale Wikipedia(Text) CC BY-SA