Usage:
Pioneer Shale of Apache Group (AZ*)
Pioneer Formation of Apache Group (AZ*)
Pioneer Quartzite of Apache Group (AZ*)
Pioneer argillite (AZ-recognized locally in Little Dragoon Mountains)
Geologic age:
Mesoproterozoic*
Type section, locality, area and/or origin of name:
Not designated. Named from old settlement of Pioneer just south of Globe quadrangle, AZ (Ransome, 1903).
AAPG geologic province:
Southwestern Basin-and-Range region
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 ([ ]).