Usage:
Zortman Member of Emerson Formation (MT)
Geologic age:
Late Cambrian and Early Ordovician
Type section, locality, area and/or origin of name:
Type section: on Lodgepole Creek at mouth of Emerson Gulch, in sec. 30, T. 26 N., R. 25 E., Phillips Co., central MT. Named from the old mining town of Zortman on southeast side of Little Rocky Mountains, Phillips Co., central MT (Lochman-Balk, 1956).
AAPG geologic province:
Williston basin
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 ([ ]).