 
                
            Wells formation divided into (ascending order):  Calder Creek, Heglar Canyon, Sublett, and Indian Fork members (all new) in Sublett Mountains, ID in the Great Basin province and Snake River basin.  Overlies Milligen formation; underlies Grandeur member of Park City formation.  New members shown only on a chart; no definition or description included in report.  [Member names should be considered invalid.]
Source: GNU records (USGS DDS-6; Denver GNULEX).
 
                
            Name applied to 1 (of 4) member of Wells Formation abandoned.  Is equivalent to Tussing Formation.  Nomenclature chart.
Source: GNU records (USGS DDS-6; Denver GNULEX).
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 ([ ]).