Frontier Formation

Frontier Formation Stratigraphic range: Late Cretaceous
Type	Geological formation
Sub-units	Torchlight Sandstone Member, Peay Sandstone Member
Underlies	Cody Shale
Overlies	Mowry Shale, Thermopolis Shale
Lithology
Primary	sandstone
Other	shale
Location
Region	North America
Country	United States
Extent	see text
Type section
Named by	W. C. Knight, 1902

The Frontier Formation is a sedimentary geological formation whose strata date back to the Late Cretaceous. The formation's extents are: northwest Colorado, southeast Idaho, southern Montana, northern Utah, and western Wyoming. It occurs in many sedimentary basins and uplifted areas.

The formation is described by W.G. Pierce as thick, lenticular, grey sandstone, gray shale, carbonaceous shale, and bentonite.

Dinosaur remains are among the fossils that have been recovered from the formation.

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