Usage:
/Eureka Member of Sapinero Mesa Tuff (CO*)
[Preoccupied. Name previously applied to Eureka Quartzite by Hague (1883) in CA,ID,NV,UT.]
Geologic age:
early Tertiary (early Oligocene; Rupelian)*
Type section, locality, area and/or origin of name:
Greatest and most typical exposure in steep walls of Animas Valley at and above Eureka Gulch, [San Juan Co.], southwestern CO (Larsen and Cross, 1956).
AAPG geologic province:
San Juan Mountains 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 ([ ]).