USGS Visual Identifier
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Geologic Unit: Eureka

Eureka Quartzite (CA*,ID*,NV*,UT*)
Eureka Quartzite of Pogonip Group (CA)
Eureka Group (CA)

Ordovician, Middle*
Ordovician, Late*

Geologic Province:
Great Basin province*

Areal Extent:

Type Locality:
Not desginated. Named from exposures at Eureka, NV (Hague, 1883). [From US geologic names lexicon, USGS Bull. 1200]
Standard section: Lone Mountain section which is along west base of Lone Mountain, about 15 mi northwest of Eureka, in T. 20 N., R. 51 E., Eureka Co., NV (Webb, 1956). [From US geologic names lexicon, USGS Bull. 1200]

GROUP STATUS (alphabetical): Barrel Spring Formation (CA), Johnson Spring Formation (CA).

Unit Name History:
Named (Hague, 1883).
Revised; Overview (Webb, 1956).
Isotopic dating (Marvin and Dobson, 1979).
Areal limits (Steven and Morris, 1983).
Mapped 1:24k in southwest UT (Hintze and Best, 1987).
Overview; Isotopic dating (Hintze and Axen, 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