Crevasse Canyon Formation

Crevasse Canyon Formation Stratigraphic range: Upper Cretaceous
Type	sedimentary
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
Named by	Allen and Balk, 1954[1]
Region	San Juan Basin (New Mexico, Arizona)
Country	United States

The Crevasse Canyon Formation is a coal-bearing Cretaceous bedrock formation in New Mexico and Arizona.

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
  • List of stratigraphic units with indeterminate dinosaur fossils

Footnotes

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	Dinosaurs portal

1. ^ ^{a b} 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.
2. ^ ^{a b} 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. [1]
3. ^ Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.
4. ^ 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.