Usage:
Rex Chert Member of Phosphoria Formation (ID*,MT*,UT*,WY*)
Rex Tongue of Phosphoria Formation (UT*)
Geologic age:
Permian, Early*
Guadalupian, early*
Wordian*
Type section, locality, area and/or origin of name:
Not designated. Named from Rex Peak in the Crawford Mountains, Rich Co., UT (Richards and Mansfield, 1912).
AAPG geologic province:
Wasatch uplift*
Montana folded belt*
Snake River basin*
Green River 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 ([ ]).