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*