Point Lookout Sandstone
| Mesaverde Group|
Sandstone, Mudstone, Coal
| Dilco Coal Member, Dalton Sandstone Member, Gibson Coal Member|
San Juan Basin (New Mexico, Arizona)
The Crevasse Canyon Formation is a coal-bearing Cretaceous bedrock formation in New Mexico and Arizona.
Crevasse Canyon Formation Wikipedia
The formation was originally described in 1954 by Allen and Balk as part of the Mesaverde Group.
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.
Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.
Petrified wood is common in the Gibson Coal Member.
Tschudy (1976) identified the Crevasse Canyon formation as Coniacian and Santonian by palynology of coal and shale.