Usage:
Bobtail Quartz Latite Member of Gem Hill Formation of Tropico Group (CA*)
Geologic age:
late Tertiary (Miocene)*
Type section, locality, area and/or origin of name:
Type locality: Soledad Mountain, in secs. 6 and 7, T. 10 N., R. 12 W., San Bernardino Base and Meridian, Rosamond 15-min quadrangle, Kern Co., south-central CA. Named from Bobtail Mines on west slope of Soledad Mountain. Many scattered buttes within 10 mi of Soledad Mountain are remnants of volcanic plugs made up of Bobtail quartz latite (Dibblee, 1958).
AAPG geologic province:
San Joaquin basin*
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 ([ ]).