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National Geologic Map Database

Geologic Unit: Alger

Usage:

Alger Formation (KY)
Alger Shale of Crab Orchard Group (KY*-local)


Subunits:

(alphabetical): Dayton Dolomite Member (KY*-local), Estill Shale Member (KY*-local), Laurel Member (OH), Lulbegrud Shale Member (KY*-local), Massie Member (OH), Waco Member (KY*-local).


Geologic age:

early Early Silurian (Llandovery)*


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

Named from Alger Station on the Louisville and Atlantic RR, between Panola and Irvine, about 1 mi east of Estill-Madison Co. line, east-central KY (Foerste, 1906).


AAPG geologic province:

Appalachian basin*
Cincinnati arch*


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 ([ ]).