Usage:
Blackleaf Formation of Colorado Group (MT*)
Subunits:
(alphabetical) --all in MT: Bootlegger Member*, Dunkleberg Member, Flood Member*, Taft Hill Member*, Vaughn Member*.
Geologic age:
late Early to early Late(?) Cretaceous (Albian to Cenomanian?)*
Type section, locality, area and/or origin of name:
Named from exposures on Blackleaf Creek, along which the beds are well developed, Teton Co., northwestern MT (Stebinger, 1918).
AAPG geologic province:
Montana folded belt*
Sweetgrass 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 ([ ]).