Usage:
Claggett Formation of Montana Group (MT*)
Claggett Shale of Montana Group (MT*)
Claggett Member of Cody Shale (MT*)
Subunits:
FORMATION STATUS (alphabetical) --all in MT*: Ardmore Bentonite Beds, Parkman Sandstone Member.
Geologic age:
Late Cretaceous (Campanian)*
Type section, locality, area and/or origin of name:
Not designated. Named from Fort Claggett, Fergus Co., MT (Hatcher and Stanton, 1903).
AAPG geologic province:
Powder River basin*
Central Montana uplift*
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 ([ ]).