Usage:
Crookston Bridge Member of Valentine Formation of Ogallala Group (NE,SD)
Geologic age:
late Tertiary (Miocene; Barstovian NALMA)
Type section, locality, area and/or origin of name:
Type section: Crookston Bridge quarry, one-eighth mi below confluence of Snake and Niobrara Rivers, in SW/4 NW/4 sec. 1, T. 32 N., R. 30 W., northern Cherry Co., central northern NE (Skinner and others, 1968; = section published by Johnson, 1936, Amer. Jour. Sci., v. 31, fig. 2).
AAPG geologic province:
Chadron arch
Salina 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 ([ ]).