Benton Shale Stratigraphic range: Cretaceous |
|
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Type | Formation |
Underlies | Niobrara Formation |
Overlies | Dakota Sandstone |
Lithology | |
Primary | Shale |
Other | Limestone, sandstone, bentonite |
Location | |
Region | Montana, Wyoming, North Dakota, South Dakota, Colorado, Nebraska |
Country | United States |
Type section | |
Named for | Fort Benton, Montana |
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.