Meganos Formation (CA*)
Marysville Claystone Member.
Paleocene*
Named from exposures on Meganos Ranch or land grant, southeast of Martinez, Contra Costa Co., west-central CA (Clark, 1918).
Redesignated to strip beginning about 1.5 mi east and a little north of Clayton and ending in vicinity of Byron Hot Springs, Contra Costa Co., CA (Clark and Woodford, 1927).
Sacramento 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 ([ ]).