Chinle Formation

Chinle Formation
Stratigraphic range: Norian–Rhaetian PreꞒ Ꞓ O S D C P T J K Pg N
Chinle Badlands, Grand Staircase–Escalante National Monument, Utah, US.
Type	Geological formation
Sub-units	see text
Underlies	Wingate Sandstone, Moenave Formation, Nugget Sandstone
Overlies	Moenkopi Formation or Cutler Group
Lithology
Primary	fluvial mudstone, siltstone, and sandstone
Other	paleosols
Location
Coordinates	36°09′18″N 109°34′44″W / 36.155°N 109.579°W / 36.155; -109.579
Approximate paleocoordinates	10°42′N 48°18′W / 10.7°N 48.3°W / 10.7; -48.3
Region	Colorado Plateau
Extent	Utah Colorado New Mexico Arizona Nevada
Type section
Named for	Chinle, AZ
Named by	Herbert E. Gregory
Chinle Formation (the United States) Show map of the United States Chinle Formation (Arizona) Show map of Arizona Type locality in Arizona

The Chinle Formation is an Upper Triassic continental geological formation of fluvial, lacustrine, and palustrine to eolian deposits spread across the U.S. states of Nevada, Utah, northern Arizona, western New Mexico, and western Colorado. In New Mexico, it is often raised to the status of a geological group, the Chinle Group. Some authors have controversially considered the Chinle to be synonymous to the Dockum Group of eastern Colorado and New Mexico, western Texas, the Oklahoma panhandle, and southwestern Kansas. The Chinle Formation is part of the Colorado Plateau, Basin and Range, and the southern section of the Interior Plains.^[1] A probable separate depositional basin within the Chinle is found in northwestern Colorado and northeastern Utah. The southern portion of the Chinle reaches a maximum thickness of a little over 520 meters (1,710 ft). Typically, the Chinle rests unconformably on the Moenkopi Formation.

The Chinle Formation was probably mostly deposited in the Norian stage, according to a plethora of chronological techniques. It is a thick and fossiliferous formation with numerous named members (subunits) throughout its area of deposition.