Usage:
Siemens Creek Formation of Powder Mill Group of Keweenawan Supergroup (MI*,WI*)
Siemens Creek Volcanics of Powder Mill Group (MI*,WI*)
Geologic age:
Mesoproterozoic*
Type section, locality, area and/or origin of name:
Along Powder Mill Creek valley and hills to east, in secs. 5 and 8, T. 47 N., R. 46 W., and in sec. 33, T. 48 N., R. 44 W., Gogebic Co., northwest MI (Upper Peninsula). Named from Siemens Creek, west of town of Bessemer (Hubbard, 1975).
AAPG geologic province:
Wisconsin 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 ([ ]).