Usage:
No current usage.
(†Ahorn Sandstone or †Ahorn Quartzite (MT) replaced with McNamara Formation and Bonner Quartzite, both of Missoula Group of Belt Supergroup. See McNamara and Bonner.)
Geologic age:
Mesoproterozoic
Type section, locality, area and/or origin of name:
[Type locality not designated.] Notable exposures in Saypo quadrangle, [in Teton Co.], and Silvertip quadrangle, [in Lewis and Clark Co.], northwestern MT. Named from Ahorn Creek in southeastern corner of Silvertip quadrangle, [Lewis and Clark Co.], northwestern MT, where headward part of creek is incised in these rocks (Deiss, 1943).
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 ([ ]).