USGS Visual Identifier
National Geologic Map Database logo GEOLEX database

Geologic Unit: Nicholas

Nicholas Bed of the Tanglewood Limestone Member of the Lexington Limestone (KY*)

Ordovician, Middle*
Ordovician, Late*
Geologic Province:
Cincinnati arch*

Areal Extent:

Type Locality:
Type area: Nicholas Co., KY; typically exposed between Pleasant Valley and Millersburg, KY (Foerste, 1909).

Unit Name History:
[Only the Foerste (1909), Black and others (1965), Cressman (1973), and Frey (1995) publications were compiled for this unit.]
Named Nicholas bed of Cynthiana formation (Foerste, 1909). Not used (Foerste, 1924) [GNC files]. Used as a facies of Greendale limestone (McFarlan and Young, 1935) [GNC files]. Used as a division of Cynthiana formation (McFarlan and White, 1948) [GNC files]. Revised to Nicholas limestone member of Cynthiana formation (Hamilton, 1950) [GNC files]. Biostratigraphic dating; Revised (Lattman, 1954) [GNC files]. Revised to Nicholas Limestone Member of Lexington Limestone (Black and others, 1965). Revised to Nicholas Bed of Tanglewood Limestone Member of Lexington Limestone; Age modified (Cressman, 1973). Age modified (Frey, 1995).

Note: If you need more information, please contact Nancy Stamm (
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
Database project personnel
Last modified: 15-Jan-2013