Millbrig Bentonite Bed of Glencoe Member of Spechts Ferry Formation (IL,WI)
Millbrig Bentonite Bed of Decorah Formation (IA,MN*,MO)
Millbrig K-bentonite Bed of Carters Limestone (AL,GA,TN)
Millbrig K-bentonite Bed of Eggleston Formation (TN,VA,WV)
Millbrig K-bentonite Bed of Moccasin Formation (TN,VA,WV)
Millbrig K-bentonite Bed of Chickamauga Limestone (AL)
Millbrig K-bentonite Bed of Colvin Mountain Sandstone (AL)
Millbrig K-bentonite Bed of Tyrone Limestone (KY)
Millbrig K-bentonite Bed of Bays Formation (TN,VA)
/Millbrig K-bentonite Bed of Stones River Group (AL)
Middle Ordovician (Rocklandian)*
Type section: Millbrig Southeast section, along east bank of Galena River, 1.6 km southeast of Millbrig, in center sec. 34, T. 29 N., R. 1 E., Jo Daviess Co., IL. Named from Millbrig (Willman and Kolata, 1978).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.
"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).