U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Portal

Usage:

Portal Formation (AZ*,NM)


Geologic age:

Late Devonian


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

Type section: about 2 mi northwest of village of Portal, Cochise Co., southeastern AZ. Exposed in SW/4 sec. 14, T. 17 S., R. 31 E., where formation forms ridge between Round Valley on north and Silver Creek on south. Named from Portal (Sabins, 1957).


AAPG geologic province:

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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).