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Welcome to the
National Geologic Map Database logo
Geologic Names Lexicon

GEOLEX is a search tool for lithologic and geochronologic unit names.
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link to comprehensive search

use all
search criteria

link to quick search

use most
common criteria

link to North American Stratigraphic Code
(American Association of
Petroleum Geologists
button link to NGM home page

GEOLEX completion thermometer 75 percent
Completion status of the Database

The Geolex database contains 16,072 entries. 75% of the unit names from the USGS Geologic Names Committee (GNC) card catalog have been entered in the database. Several thousand unit names remain to be checked and entered.

90% of the unit names from the CD-ROM, "Stratigraphic Nomenclature Databases for the United States, its Possessions and Territories," DDS-6, 1996, USGS, have been entered.

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Your are welcome.

The National Geologic Map Database and GEOLEX are managed by the USGS's National Cooperative Geologic Mapping Program in cooperation with the Association of American State Geologists.

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U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
Database project personnel.
Last Modified : July 20, 2012
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