U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Eureka

Usage:

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


Subunits:

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


Geologic age:

late Middle to Late Ordovician*


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

Not desginated. Named from exposures at Eureka, NV (Hague, 1883).
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).


AAPG geologic province:

Great Basin province*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"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 conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).