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

Geologic Unit: Barker

Usage:

Barker Porphyry (MT*)


Geologic age:

early Tertiary (Eocene)*


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

Type locality not stated. Forms Big Baldy Mountain to south of Barker, Little Belt Mountains, central MT; [also forms Barker Mountain, in Fort Benton quadrangle] (Weed, 1899).


AAPG geologic province:

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 ([ ]).