Usage:
Tropic Shale (UT*)
Geologic age:
Late Cretaceous (Cenomanian to Turonian)*
Type section, locality, area and/or origin of name:
Not designated. Named from excellent exposures around the town of Tropic, Garfield Co., UT (Gregory and Moore, 1931).
AAPG geologic province:
Paradox basin*
Plateau sedimentary province*
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 ([ ]).