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National Geologic Map Database

Geologic Unit: Belle Fourche

Usage:

Belle Fourche Shale (MT*,ND*,SD*,WY*)
Belle Fourche Formation (MT*)
Belle Fourche Shale of Colorado Group (ND,SD)
Belle Fourche Formation of Colorado Group (ND)
Belle Fourche Member of Frontier Formation (WY*)
Belle Fourche Member of Graneros Shale (SD)


Subunits:

FORMATION STATUS (alphabetical): Big Elk Sandstone Member (MT), Clay Spur Bentonite Bed (WY), Mosby Sandstone Member (MT*).
MEMBER STATUS: Soap Creek Bentonite Bed (MT*,WY*).


Geologic age:

early Late Cretaceous (Cenomanian)*


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

Named from exposure along Belle Fourche River in neighborhood of Wind Creek, [in T. 50 N., R. 67 W.], Crook Co., northeastern WY (Collier, 1922).


AAPG geologic province:

Central Montana uplift*
Montana folded belt*
Chadron arch*
Williston basin*
Powder River basin*
Wind River basin*
Green River basin*
Sweetgrass arch*


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 ([ ]).