Usage:
DeGrey Member of Pierre Shale (NE*,ND*,SD*)
Geologic age:
Late Cretaceous (Campanian)*
Type section, locality, area and/or origin of name:
Type locality: west edge of NW/4, sec. 8, T. 109 N., R. 75 W., Hughes Co., central SD. Named from DeGrey Post Office and store. Type section is 2 mi southeast of DeGrey in cut-bank of Missouri River (Crandell, 1950).
AAPG geologic province:
Salina basin*
Sioux uplift*
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 ([ ]).