Usage:
Powder Mill Group of Keweenawan Supergroup (MI*,WI*)
Subunits:
(ascending) --all in MI*,WI*: Siemens Creek Formation, Kallander Creek Formation.
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., MI (Hubbard, 1975).
AAPG geologic province:
Lake Superior region*
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 ([ ]).