Usage:
Unkpapa Sandstone (SD*,WY*)
Unkpapa Sandstone Member of Morrison Formation (SD*)
Geologic age:
Jurassic, Late*
Type section, locality, area and/or origin of name:
In the southern Black Hills, on ridges east and south of Hot Springs, Fall River Co., SD (Darton and O'Harra, 1909).
AAPG geologic province:
Chadron arch*
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 ([ ]).