Usage:
Horquilla Limestone of Naco Group (AZ*,NM*)
Horquilla Formation (NM)
Geologic age:
Pennsylvanian, Early*
Pennsylvanian, Middle*
Pennsylvanian, Late*
Permian, Early*
Type section, locality, area and/or origin of name:
Type section: on eastern spur of Horquilla Peak in the Tombstone Hills, Cochise Co., AZ (Gilluly and others, 1954).
AAPG geologic province:
Pedregosa basin*
Basin-and-Range 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 ([ ]).