Usage:
Collins Ranch Member of Tullock Formation (MT)
Geologic age:
Tertiary
Paleocene, early
Type section, locality, area and/or origin of name:
Type section: sec. 12, T. 22 N., R. 43 E., McCone Co., MT (Rigby and Rigby, 1990).
AAPG geologic province:
Williston basin
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 ([ ]).