Usage:
By-Day Member of Eureka Valley Tuff of Stanislaus Group (CA*,NV*)
Geologic age:
Tertiary
Miocene, late*
Type section, locality, area and/or origin of name:
Exposures on north bank of By-Day Creek, Lat. 38 deg. 16 min. 20 sec. N., Long. 119 deg. 18 min. 45 sec. W., Mono Co., CA. Origin of name not stated by authors, but probably named from By-Day Creek (Noble and others, 1974).
AAPG geologic province:
Sierra Nevada 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 ([ ]).