Usage:
Pony Gneiss (MT)
Pony metamorphics [informal] (MT)
/Pony Group (MT)
For informal usage, the rank or lithologic term should not be capitalized. [A "group" consists of 2 or more formations (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021).]
Geologic age:
Archean
Type section, locality, area and/or origin of name:
Named from exposures at and in vicinity of town of Pony, Madison Co., southwestern MT (Tansley and others, 1933).
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 ([ ]).