No current usage.
(Rocks of †Jacksboro Formation of Cisco Group (TX) reallocated Graham Formation. See Graham.)
Late Pennsylvanian (Virgilian)
Notable exposures in sandstone hills southwest of Jacksboro, Jack Co., and also in Young Co., central northern TX (US geologic names lexicons, USGS Bull. 896, 1200).
Bend arch
Fort Worth syncline
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 ([ ]).