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National Geologic Map Database

Geologic Unit: Millboro

Usage:

Millboro Shale (MD,PA,VA*,WV*)
Millboro Member of Romney Shale (VA)
Millboro Member of Chattanooga Shale (TN)


Subunits:

Purcell Member (VA), Marcellus Member (VA), Naples Member (VA).


Geologic age:

Middle Devonian*


Type section, locality, area and/or origin of name:

Millboro Springs, Bath Co., VA (Butts, 1940).


AAPG geologic province:

Appalachian basin*


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 ([ ]).