Garita Creek Formation

Garita Creek Formation
Stratigraphic range: Carnian PreꞒ Ꞓ O S D C P T J K Pg N
Type	Formation
Unit of	Chinle Group
Underlies	Trujillo Formation
Overlies	Santa Rosa Formation
Thickness	122–152 meters (400–499 ft)
Lithology
Primary	Shale
Location
Coordinates	35°17′59″N 104°25′11″W / 35.2998°N 104.4198°W / 35.2998; -104.4198
Region	New Mexico
Country	United States
Type section
Named for	Garita Creek
Named by	Lucas and Hunt
Year defined	1989
Garita Creek Formation (the United States) Show map of the United States Garita Creek Formation (New Mexico) Show map of New Mexico

The Garita Creek Formation is a geologic formation in New Mexico that contains vertebrate fossils characteristic of the Carnian Age of the late Triassic .^[1]

The formation may be synonymous with the Tecovas Formation in Texas.^[2]

Description

The formation consists mostly of gray red to red or mottled gray green mudstone containing limestone nodules. About 25% of the formation is massive fine-grained laminar gray red sandstone. It rests conformably on the Santa Rosa Formation, and is overlain disconformably by the Trujillo Formation. The total thickness of the formation is 122–152 meters (400–499 ft). It is exposed throughout the drainage of the Conchas River and its tributaries^[1] west to the Sangre de Cristo Mountains.^[3]

Fossils

The formation contains vertebrate fossils of Desmatosuchus, Typothorax, Paratypothorax, Postosuchus, rauisuchians, metoposaurids, Ceratodus, and indeterminate phytosaurs.^[1]

History of investigation

The formation was first named by Lucas and Hunt in 1989 for beds formerly assigned to the informal lower shale member of the Chinle Formation in the Tucumcari Basin.^[1] The formation definition has been criticized as a junior synonym for the Tecovas Formation across the border in Texas.^[2]

See also

• List of dinosaur-bearing rock formations
  • List of stratigraphic units with indeterminate dinosaur fossils

Footnotes

References

• Lehman, T.M. (1994). "The saga of the Dockum Group and the case of the Texas/New Mexico boundary fault" (PDF). New Mexico Bureau of Mines & Mineral Resources Bulletin. 150: 37–51. Retrieved September 1, 2020.
• Lucas, S.G.; Hunt, A.P. (1989). "Revised Triassic stratigraphy in the Tucumcari basin, east-central New Mexico". In Lucas, S.G.; Hunt, A.P. (eds.). Dawn of the age of dinosaurs in the American southwest. New Mexico Museum of Natural History and Science. pp. 150–170. Retrieved September 17, 2020.
• Lucas, S.G.; Hunt, A.P.; Huber, P. (1990). "Triassic stratigraphy in the Sangre de Cristo Mountains, New Mexico" (PDF). New Mexico Geological Society Field Conference Guidebook. 41: 305–318. Retrieved September 17, 2020.

This page was last edited on 23 December 2023, at 06:48