Crevasse Canyon Formation
The Crevasse Canyon Formation is a coal-bearing Cretaceous bedrock formation in New Mexico and Arizona.
| Crevasse Canyon Formation Stratigraphic range: Santonian | |
|---|---|
| Type | Formation |
| Unit of | Mesaverde Group |
| Sub-units | Dilco Coal Member, Dalton Sandstone Member, Gibson Coal Member |
| Underlies | Point Lookout Sandstone |
| Overlies | Gallup Sandstone |
| Lithology | |
| Primary | Sandstone, mudstone, coal |
| Location | |
| Region | San Juan Basin (New Mexico, Arizona) |
| Country | United States |
| Type section | |
| Named by | Allen and Balk |
| Year defined | 1954[1] |
Description
The formation was originally described in 1954 by Allen and Balk as part of the Mesaverde Group.[1]
The formation is divided into three members, in ascending stratigraphic order: Dilco Coal Member, Dalton Sandstone Member, and Gibson Coal Member. The Dilco Coal Member is described by Cather (2010) as "Drab mudstone, fine- to medium-grained sandstone, and coal. Sandstone is commonly crossbedded or ripple laminated." The Dalton Sandstone Member is described as "Gray to yellowish gray, fine- to medium-grained, cliff-forming sandstone." The Gibson Coal Member is described as "Drab mudstone, buff, brown, and greenish gray sandstone (commonly cross-bedded), and coal," with the coals typically less than 0.5 m thick.[2]
Fossils
Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.[3]
Petrified wood is common in the Gibson Coal Member.[2]
Age
Tschudy (1976) identified the Crevasse Canyon formation as Coniacian and Santonian by palynology of coal and shale.[4]
See also
- List of dinosaur-bearing rock formations
Footnotes
- Allen, J.E., and Balk, Robert, 1954, Mineral Resources of Fort Defiance and Tohatchi quadrangles, Arizona and New Mexico: New Mexico Bureau of Mines and Mineral Resources Bulletin, no. 36, 192 p.
- Cather, Steven, 2010, Preliminary geologic map of the San Lucas Dam quadrangle, McKinley County, New Mexico: New Mexico Bureau of Geology and Mineral Resources, Open-File Geologic Map OF-GM 212, scale 1:24000.
- Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.
- Tschudy, R.H., 1976, Palynology of Crevasse Canyon and Menefee Formation of San Juan basin, New Mexico, IN Beaumont, E.C., Shomaker, J.W., and Stone, W.J., compilers, Guidebook to coal geology of northwest New Mexico: New Mexico Bureau of Mines and Mineral Resources Circular, no. 154, p. 48-55.
References
- Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.