Usage:
Bearpaw Shale of Montana Group (MT*)
Bearpaw Shale (WY*)
Bearpaw Shale Member of Sedan Formation of Livingston Group (MT*-local)
Geologic age:
Late Cretaceous (Campanian and Maastrichtian)*
Type section, locality, area and/or origin of name:
Named from exposures at north, east, and south borders of Bearpaw Mountains, Blaine Co., MT (Hatcher and Stanton, 1903).
Reference section: in SW/4 sec. 17 and SE/4 sec. 18, T. 4 N., R. 8 E., Park Co., MT (Skipp and McGrew, 1977).
AAPG geologic province:
Bighorn basin*
Central Montana uplift*
Montana folded belt*
Powder River basin*
Sweetgrass arch*
Williston basin*
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 ([ ]).