Walnut Gap Formation (AZ*)
Jurassic* or Triassic*
Type section: on Scherrer Ridge near southeast end of Walnut Gap in the Gunnison Hills, Cochise Co., AZ. Named from Walnut Gap (Cooper and Silver, 1964).
Pedregosa 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 ([ ]).