Usage:
Crazy Johnson Member of Chadron Formation of White River Group (SD)
Geologic age:
early Tertiary (early Oligocene)
Type section, locality, area and/or origin of name:
Type locality: at standard section of Chadron formation in Big Badlands on south fork of Indian Creek, Pennington Co., SD, from sec. 34, T. 3 S., R. 12 E., to sec. 10, T. 4 S., R. 12 E. Named from prominent butte in southern part of sec. 10, T. 4 S., R. 12 E., locally known as Crazy Johnson Butte. [Same butte also called Peanut Peak, the name given to the overlying Peanut Peak member of Chadron.] (Clark, 1954).
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 ([ ]).