An earthquake with a preliminary magnitude of 2.5 struck near Concord Monday afternoon, according to the U.S. Geological Survey.
The temblor was reported at 2:52 p.m. about a mile west-northwest of Concord, USGS officials said.
The quake had a depth of 10 miles, according to the USGS.
An earthquake of the same magnitude struck about 24 hours earlier in another part of Contra Costa County near the unincorporated community of Blackhawk.
Copyright © 2014 by Bay City News, Inc. Republication, re-transmission or reuse without the express written consent of Bay City News, Inc. is prohibited.