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National Geologic Map Database

Geologic Unit: Earp

Usage:

Earp Formation of Naco Group (AZ*,NM*)


Geologic age:

Pennsylvanian, Late* (local)
Permian, Early* (local)


Type section, locality, area and/or origin of name:

Type section: extends from saddle south of Earp Hill up to conspicuous mottled, pink and gray limestone, and then (to avoid faulting at this locality) is completed by exposed section above this mottled bed about 0.5 mi to east on the same slope. Named from Earp Hill in sec. 5, T. 21 S., R. 23 E., on whose slope lower part of formation is well exposed, central Cochise Co, southeastern AZ. There is no continuous, unfaulted section of entire formation in area of northern Mule Mountains, Tombstone Hills, or Dragoon Mountains, included in Pearce and Benson quadrangles, 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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).