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National Geologic Map Database

Geologic Unit: Graham

Usage:

Graham Formation of Cisco Group (TX*)
Graham Shale of Cisco Group (OK)
Graham Group (TX)


Subunits:

GROUP STATUS (alphabetical) --all in TX: [?]Gunsight Limestone, [?]Ivan Limestone, North Leon Formation, Rocky Mound Limestone, [?]Wayland Shale.
FORMATION STATUS --in OK: Garner Sandstone Member.
FORMATION STATUS (alphabetical) --all in TX: Bluff Creek Shale Member*, Bunger Limestone Member*, Eastland Sandstone Member, Finis Shale Member, Gonzales Limestone Member*, Gonzales Creek Shale Member, Gunsight Limestone Member*, Ivan Limestone Member*, Jacksboro Limestone Member*, Necessity Shale Member, North Leon Limestone Member*, Rocky Mound Limestone Member*, Salem School Limestone Member*, Wayland Shale Member*, White Ranch Limestone [Bed].


Geologic age:

Late Pennsylvanian (Virgilian)*


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

Type locality: bluff on Salt Creek, west of Graham, Young Co., [Brazos River region], central northern TX (Plummer and Hornberger, 1936).
Named from Graham, the county seat of Young Co., [Brazos River region], central northern TX (Plummer and Moore, 1922).


AAPG geologic province:

Bend arch*
Fort Worth syncline*
South Oklahoma folded belt


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 ([ ]).