Usage:
No current usage?
(†Clyde Formation of Wichita Group (TX*) or †Clyde Group (TX) considered obsolete?)
Subunits:
[†?] GROUP STATUS (alphabetical) --all in TX: Grape Creek Formation, Talpa Formation.
[†?] FORMATION STATUS (alphabetical) --all in TX*: Grape Creek Limestone Member, Talpa Limestone Member.
Geologic age:
early Permian (Leonardian)*
Type section, locality, area and/or origin of name:
Named from town of Clyde, 8 mi west of Baird, Callahan Co., TX. It is a poor name because in vicinity of the town the Permian is covered by Cretaceous sand and it is necessary to go several mi south of town to get good exposures. But it is only locality along its outcrop available as a name (Plummer and Moore, 1922).
AAPG geologic province:
Bend arch*
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 ([ ]).