No current usage.
(†Gunnison Formation (CO*) is same as Morrison Formation. See Morrison.)
Late Jurassic
Named from exposures in canyon of Gunnison River, Delta and Mesa Cos., central western CO (US geologic names lexicons, USGS Bull. 896, 1200).
Piceance basin
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).