Usage:
Coberly Formation of Colorado Group (MT*)
Geologic age:
Late Cretaceous (Cenomanian to Turonian)*
Type section, locality, area and/or origin of name:
Type section (composite): upper 310 ft measured in [either N/2 or NE/2] sec. 21, T. 10 N., R. 11 W., Powell Co., MT, lower 260 ft in E/2 sec. 8, T. 10 N., R. 11 W., Powell Co., MT, east and north of Jens respectively. Named from Coberly Gulch, about 6 mi southeast of Drummond, Granite Co., MT, where it is exposed along Coberly syncline for nearly 4 mi (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 ([ ]).