Usage:
Ladd Formation (CA*)
Subunits:
(alphabetical) --all in CA*: Baker Canyon Conglomerate Member or Baker Canyon Member, Holz Shale Member.
Geologic age:
Late Cretaceous*
Type section, locality, area and/or origin of name:
Region immediately west of mouth of Ladd Canyon, tributary of Silverado Canyon [Lat. 33 deg. 44 min. 51 sec. N., Long. 117 deg. 38 min. 23 sec. W., El Toro 7.5-min quadrangle, Orange Co., CA] (Popenoe, 1942).
AAPG geologic province:
Peninsular Ranges 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 ([ ]).