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National Geologic Map Database

Geologic Unit: Cone

Usage:

Cone Member of Marias River Shale of Colorado Group (MT*)


Geologic age:

Late Cretaceous (Cenomanian to Turonian)*


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

Type section: in NW/4 SE/4 sec. 13, T. 22 N., R. 1 W., Toole Co., MT. Named from USGS vertical-angle bench mark (VABM) "Cone" at location of type (Cobban and others, 1959).


AAPG geologic province:

Montana folded belt*
Sweetgrass arch*


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 conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).