Here is a little bit of information about the two local faults we have in Concord & Clayton, and provide a few important links.
We’ll start with the Concord Fault. Although it’s not a major fault, it’s an active one. A lot of people don’t know about the Concord Fault, which runs north through Concord to Suisun Bay. There was a damaging 5.4 magnitude quake in 1955, and the USGS says there’s a chance it could produce a 6.7 magnitude quake before the year 2030.
Another fault in our area is the Clayton-Marsh Creek Fault. This fault is also active and continues to elevate Mt.Diablo.
According to the USGS maps pictured above, it looks like the Concord fault goes from above Crystyl Ranch into Lime Ridge, over Ygnacio, continues through Lime Ridge, over Treat Boulevard, down to Systron Drive and San Miguel, then it runs right under the BART tracks near Systron Drive and San Miguel Road, apparently you can see several cracks in the pavement that were created by the activity on the fault. It then goes through Downtown Concord and on to Pacheco. The red dot that says “Concord” is about where Concord BART is located (see top photo).
As for the Clayton fault, it goes in between Seeno’s house on the hill and the Concord Pavilion, then into the hills where it goes in several different directions from there. You can click on the top picture for a larger view.