Usage:
No current usage.
(Rocks of †Greenhorn Mountain Quartzite (MT*-local) reallocated to Bonner Quartzite of Missoula Group of Belt Supergroup. See Bonner.)
Geologic age:
Precambrian
Type section, locality, area and/or origin of name:
Constitutes country rock of Continental Divide, making up bulk of Greenhorn Mountain, which forms highest summit between Mullan Pass and Marysville, [in NE/4 sec. 23, T. 11 N., R. 6 W., Greenhorn Mountain 7.5-min quadrangle, Lewis and Clark Co., Helena National Forest, central western MT (Knopf, 1950).
AAPG geologic province:
Northern Rocky Mountain region
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 ([ ]).