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National Geologic Map Database

Geologic Unit: Graneros

Usage:

Graneros Shale of Colorado Group (CO*,IA*,KS*,MN*,MT*,NM,NE*,ND*,OK*,SD*,WY*)
Graneros Shale of Benton Group (CO*,SD)
Graneros Shale (CO*,NM*,TX*)
Graneros Shale Member of Mancos Shale (CO*,NM*)
Graneros Shale Member of Benton Shale (CO*)


Subunits:

FORMATION STATUS (alphabetical): Belle Fourche Member (SD), Mowry Member (SD,WY), Nefsy Member (WY), Skull Creek Member (SD), Thatcher Limestone Member (CO*,NM*).


Geologic age:

early Late Cretaceous (Cenomanian)*


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

Named from Graneros Creek [in Walsenburg quadrangle, Pueblo Co.], CO (Gilbert, 1896). [See detailed information in Stose, G.W., 1912, Description of the Apishapa quadrangle [Colorado], USGS Geol. Atlas of the U.S., Apishapa folio, no. 186, 12p.]
Principal reference section: at Rock Canyon anticline, a few mi west of Pueblo, in SW/4 sec. 30, T. 20 S., R. 65 W., and in NW/4 NE/4 sec. 36, T. 20 S., R. 66 W., Pueblo Co., CO (Cobban and Scott, 1972).


AAPG geologic province:

Chadron arch*
Denver basin*
Iowa shelf*
Las Vegas-Raton basin*
Powder River basin*
San Juan basin*
Sierra Grande uplift*
Sioux uplift*
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 ([ ]).