Usage:
Ferdig Member of Marias River Formation (MT*)
Geologic age:
Late Cretaceous (Turonian)*
Type section, locality, area and/or origin of name:
Type section (composite): exposures 3 to 5 mi northwest of Ferdig [in sec. 36, T. 34 N., R. 1 W.], and exposures 8 mi southeast of Ferdig [in secs. 1, 12, and 13, T. 35 N., R. 2 W.], Toole Co., MT. Named from Ferdig Post Office, in southeast corner sec. 30, T. 35 N., R. 1 W., Toole Co., MT (Cobban and others, 1959).
AAPG geologic province:
Sweetgrass arch*
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 ([ ]).