| Frontier Formation | |
|---|---|
| Stratigraphic range: Cenomanian-Coniacian | |
_14_(48822462432).jpg) Frontier Formation in Utah (Dinosaur National Monument) | |
| 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[1] |
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.[2]
Dinosaur remains are among the fossils that have been recovered from the formation.[3]
- ^ W.C. Knight, 1902, Eng. and Min. Jour., v. 73, p. 721
- ^ Pierce, W.G., 1997, Geologic map of the Cody 1 degree x 2 degrees quadrangle, northwestern Wyoming: U.S. Geological Survey, Miscellaneous Geologic Investigations Map I-2500, scale 1:250000.
- ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. ISBN 0-520-24209-2.