U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Clay Spur

Usage:

Clay Spur Bentonite Bed of Mowry Shale (MT*,SD*,WY*)
Clay Spur Bentonite of Belle Fourche Shale (WY)


Geologic age:

early Late Cretaceous (Cenomanian)*


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

Not designated. Named from exposures near Clay Spur, in sec. 30, T. 47 N., R. 63 W., Weston Co., WY (Rubey, 1931).


AAPG geologic province:

Central Montana uplift
Chadron arch
Powder River basin*
Williston basin*
Wind River 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 ([ ]).