Usage:
Dunkleberg Formation of Colorado Group (MT)
Dunkleberg Member of Blackleaf Formation of Colorado Group (MT)
Geologic age:
Early Cretaceous (Albian)
Type section, locality, area and/or origin of name:
Type section: in an unnamed gulch-network, which drains low hills on southwest side of Saddle Mountain, E/2 sec. 8, T. 10 N., R. 11 W., Powell Co., MT. Named from Dunkleberg Ridge and Creek, Powell Co., MT (Gwinn, 1961).
AAPG geologic province:
Montana folded belt
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 ([ ]).