USGS Visual Identifier
National Geologic Map Database logo GEOLEX database


Geologic Unit: Millbrig

Usage:
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 (VA,WV,TN)
Millbrig K-bentonite Bed of Moccasin Formation (VA,WV,TN)
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)

Age:
Ordovician, Middle*
Champlainian*
Rocklandian*
Mohawkian







Geologic Province:
Wisconsin arch
Illinois basin
Iowa shelf
Sioux uplift*
Appalachian basin
Cincinnati arch





Areal Extent:
IL
WI
IA
MN*
MO
KY
TN
AL
GA
VA
WV

Type Locality:
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 (Willman and Kolata, 1978).

Unit Name History:
Named (Willman and Kolata, 1978).
Extended into IA, MN, and MO (Kolata and others, 1986).
Extended into KY, TN, AL, GA, and VA (Huff and Kolata, 1990).
Correlated with European bentonite (Huff and others, 1992).
Extended into WV (Haynes, 1992).
Revised; Areal limits (Haynes, 1994).
Overview (Frey, 1995).

Note: If you need more information, please contact Nancy Stamm (nstamm@usgs.gov).
Asterisks (*) indicate usage by the U.S. Geological Survey. Other usages by state geological surveys.

"No current usage" implies that a name has been abandoned or that it has fallen into disuse. Former usage and, if known, replacement name given in parentheses ().

Slashes (/) indicate unit name usage violates the 1983 North American Stratigraphic Code. This violation may be explained within brackets ([ ]).






U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
URL http://ngmdb.usgs.gov/ngmdb/ngm_catalog.ora.html
Database project personnel
Last modified: 15-Jan-2013