Usage:
Milligen Formation (ID*)
Subunits:
Consists of 5 informal units in the Snake River basin (ascending): unnamed lower sand unit, Lucky Coin limestone, Triumph argillite, Cait quartzite, and Independence sandstone.
Geologic age:
Devonian*
Type section, locality, area and/or origin of name:
Not designated. Named from exposures on Milligen Creek, Blaine Co., ID (Westgate and Ross, 1930).
Reference section: measured from SW/4 NE/4 SE/4 sec. 22 to center NE/4 NW/4 sec. 23, T. 4 N., R. 21 E., Blaine Co., ID (Paull and others, 1972).
Principal reference section: on east side of Milligen Gulch, in N/2 NW/4 sec. 19, T. 4 N., R. 19 E., Hyndman Peak quadrangle, Blaine Co., ID (Sandberg and others, 1975).
AAPG geologic province:
Snake River basin*
Idaho Mountains province*
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 ([ ]).