Usage:
Chalky Buttes Member of Chadron Formation of White River Group (ND)
Geologic age:
Tertiary
Eocene, late
Type section, locality, area and/or origin of name:
Type section: east-facing slope of a north-trending ridge, in NW/4 NE/4 NE/4 sec. 25, T. 134 N., R. 101 W., in the Chalky Buttes, 6.25 mi (as the crow flies) southeast of town of Amidon, Slope Co., southwestern ND. Named from Chalky Buttes where well exposed (Murphy and others, 1993).
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 ([ ]).