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National Geologic Map Database

Geologic Unit: Opeche

Usage:

Opeche Shale (CO*,MT*,NE*,ND*,SD*,WY*)
Opeche Shale Member of Goose Egg Formation (MT*,WY*)


Geologic age:

Early Permian (late Kungurian)*


Type section, locality, area and/or origin of name:

Typically developed on Battle Creek, the Indian name of which is Opeche, [Custer Co.], western SD (Darton, 1901).


AAPG geologic province:

Chadron arch*
Denver basin*
Green River basin*
Powder River basin*
Williston basin*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).