Usage:
No current usage.
(†Dunkleberg Formation of Colorado Group (MT), or †Dunkleberg Member of Blackleaf Formation of Colorado Group (MT), replaced with Vaughn Member of Blackleaf Formation of Colorado Group. See Vaughn.)
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, in 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 ([ ]).