GEOLEX database Geologic Unit: Eureka Usage: Eureka Quartzite (CA*,ID*,NV*,UT*) Eureka Quartzite of Pogonip Group (CA) Eureka Group (CA) Age: Ordovician, Middle* Ordovician, Late* Geologic Province: Great Basin province* Areal Extent: CA* ID(se)* NV(nc)* UT(wc)* 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] Subunits: 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 (nstamm@usgs.gov). 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 URL http://ngmdb.usgs.gov/ngmdb/ngm_catalog.ora.html Database project personnel Last modified: 15-Jan-2013