GEOLEX database Geologic Unit: Roberts Mountains Usage: Roberts Mountains Formation* Age: Silurian, Early* Silurian, middle* Wenlockian* Devonian, Early* Lochkovian* Geologic Province: Snake River basin* Great Basin province* Idaho Mountains province Areal Extent: ID(c)* NV(n)* Type Locality: Type section is located on the west side of Roberts Creek Mountain [Roberts Creek Mountain 7.5-min quadrangle, Eureka Co], NV (Merriam, 1940). Unit Name History: Named (Merriam, 1940). Adopted (Nolan and others, 1956). Redescribed (Nolan and others, 1956). Biostratigraphic dating (Merriam, 1940; Radtke, 1985). Overview (Skipp and Sandberg, 1975). Age modified (Skipp and Sandberg, 1975). Areal limits; Extended into ID (Skipp, Sandberg, 1975). Overview (Skipp, Sandberg, 1975; Dover, 1983). Age modified (Dover, 1983). 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