The Trinidad Formation consists of a massive fine- to very fine-grained arkosicsandstone some 70–300 feet (21–91 m) in thickness.[1][3] It rests conformably on the Pierre Shale and is in turn conformably overlain by the Vermejo Formation.[4][2]
The formation contains trace fossils of Ophiomorpha and, in a few locations, Diplocraterion. "Ladders" of Diplocraterion are over 1 meter (3.3 ft) long in the lower part of the formation at Cerrososo Canyon.[3]
Economic geology
There is potential for natural gas extraction from the Trinidad Sandstone. The gas originates in interbedded coal formations.[6]
History of investigation
The beds making up this unit were originally included in Hayden's Raton Hills group in 1869. The name, Trinidad, was first applied by R.C. Hills in 1899, and W.T. Lee (1917) further refined the definition to include only Hills' "Upper Trinidad".[1]
Cather, Steven M. (2004). "Laramide Orogeny in Central and Northern New Mexico and Southern Colorado". In Mack, Greg H.; Giles, Katherine A. (eds.). The Geology of New Mexico: A Geologic History. New Mexico Geological Society. pp. 203–248.
Johnson, Ross B.; Wood, Gordon H. Jr. (1956). "Stratigraphy of Upper Cretaceous and Tertiary Rocks of Raton Basin, Colorado and New Mexico". AAPG Bulletin. 40 (4): 707–721. doi:10.1306/5CEAE400-16BB-11D7-8645000102C1865D.