Usage:
Thermopolis Shale (MT*,WY*)
Thermopolis Shale of Colorado Group (WY)
Subunits:
(alphabetical): [†?]Birdhead Sandstone Member (MT), Cyprian Sandstone Member (MT*), Muddy Sandstone Member (WY*).
Geologic age:
late Early Cretaceous (Albian)*
Type section, locality, area and/or origin of name:
Not designated. Named from Thermopolis, Hot Springs Co., WY (Lupton, 1916).
Reference section: in SW/4 sec. 20, T. 2 S., R. 7 E., Gallatin Co., MT (Roberts, 1972).
AAPG geologic province:
Montana folded belt*
Bighorn basin*
Chadron arch
Denver basin*
Green River basin*
Williston basin*
Snake River basin*
Wind River basin*
Powder River basin*
Central Montana uplift*
Yellowstone province*
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 ([ ]).