Usage:
Mobridge Member of Pierre Shale (NE*,ND*,SD*)
Geologic age:
Late Cretaceous (Maastrichtian)*
Type section, locality, area and/or origin of name:
Type section: roadcuts along U.S. Highway 12 at west end of bridge across Missouri River, opposite Mobridge, Corson Co., central SD. Name from Mobridge, Walworth Co., central SD (Searight, 1937).
AAPG geologic province:
Williston basin*
Salina basin*
Sioux uplift*
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 ([ ]).