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National Geologic Map Database

Geologic Unit: Skull Creek

Usage:

Skull Creek Shale (MT*,ND*,SD*,WY*)
Skull Creek Shale of Dakota Group (CO,NE)
Skull Creek Formation of Dakota Group (ND)
Skull Creek Member of Graneros Shale (SD)
Skull Creek Member of Colorado Shale (MT*)


Subunits:

Newcastle Sandstone Member (SD,WY).


Geologic age:

late Early Cretaceous (Albian)*


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

Not designated. Named from exposures along Skull Creek, southeast of Osage, Weston Co., WY (Collier, 1922).
Reference section (measured by Mapel, 1959): near Buffalo, in sec. 25, T. 49 N., R. 83 W., Johnson Co., WY (Roberts, 1972).


AAPG geologic province:

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