Hi Andrew. I’ve enjoyed your blog for a while. Now I’m looking for a home to buy and find myself wondering if YOU would buy (or even rent) in Sheffield Village? It’s one of the areas our budget has led us to, but it scares me. And then I wonder if living ON the fault is so much worse than living, say, across the freeway from the fault.
Lesley, I’m not a practicing geologist and it would be illegal for me to advise you. I can only tell you that I live less than 2 kilometers from the fault, love where I am, and am not a homeowner. I can also tell you that I adore Sheffield Village. Every homesite has its own unique geologic setting, even within a single development.
When the big one hits Oakland, we will all be in the same place.
The City of Fremont will show you around its segment of the Hayward fault in 90-minute walks on three Saturdays this summer. The first walk is next week. See more here.
While I’m at it, I will be leading a two-hour walk for the Oakland Heritage Alliance on August 18 around the landscape (and rock specimens) of Middle Harbor Park. And on September 8 I’ll lead a walk around the Hayward fault and other attractions of Montclair for Oakland Urban Paths. Mark your calendars now.
[The concentric brown bands inside massive sandstone are common in coastal California. I understand that they mark the passage of petroleum from source beds below on their way toward the surface or an underground trap. They are spectacularly exposed along the Santa Cruz beach cliffs among other places. --Andrew]
Next week—Saturday the 18th—I’ll be leading a walk for the Oakland Heritage Alliance down at Middle Harbor Park, 10 am to noon. The topic is the wonderful recycled landscape there, regarded as both an artistic and geotechnical achievement.
Hi, my apologies if I ever asked this before, my memory is bad.
I found this fossil in the railroad cut in Fernandez Park in Pinole. I realize that that is not Oakland, but thought you might know of the age of the rock there.
I thought it was a samarra (maple tree “helicopter”) mainly because it has a “bump” without veins where the seed would be, but a friend’s friend who works at UC Berkeley in Paleontology (I think) thought that sounded misplaced. Maybe it’s a shell. Dunno the age.
The original was sadly destroyed (so crumbly), and a planned field trip with him to the locality to search for others never materialized.
Michael, the contact is mapped as a thrust fault, with the Cretaceous rocks pushed over the younger ones. Moreover, the Cretaceous rocks are of Campanian age while the Tertiary rocks are Miocene, so there’s an age gap of about 50 million years there.
The nearest true K-T (Maastrichtian–Danian) contact I know of is down in the Panoche Hills.
I was reading about the Science Night at Claremont Middle School, which happened Thursday night (17 Jan). The Trib said, and Rockridge Patch confirms, that one of the events was an “Earth Science Dinner.” Can anyone tell me what was served?
Is that Round Top on the left of your banner photo? I was there recently with a friend and wondered if it could be seen from SF. I saw that ’round top’ next to Mt. Diablo on the approach to the bay bridge and wondered if it was ‘the’ Round Top where Sibley Park is.
Thanks for the confirmation. I just saw a similar view today from the Legion of Honor in SF, but because of the angle, the buildings in the forefront are downtown SF rather than downtown Oakland. It’s pretty cool to be able to see the same landmarks from different places.
On Saturday 31 August I will be leading a walk along the Hayward fault at the foot of Claremont Canyon for the Claremont Canyon Conservancy. There’s no announcement on the website. We start at 10 a.m. at the top of Dwight Way, at Fernwald Road, and will finish before noon.
Andrew — Do you know anything about Sheridan Road in upper Rockridge (see http://goo.gl/maps/2vYPJ and http://goo.gl/maps/rY2m7 ) ? The road appears to have slid away at some point, but the right of way still exists. I’m suggesting that the trail over the ROW be included in an Oakland Urban Paths walk at some point, and it would be nice to say something about the slide.
It’s an obvious landslide scar, and the slide later threatened the freeway, which is why there’s been all that repair work going on along the old railroad grade. I don’t know how old the slide is, though. The street maps show a continuous street in 1967, which is suggestive if not definitive.
See video of the slide and the work being done to mitigate it: part 1part 2
Thanks Andrew — although the slide repair now underway is a bit away from the area where the road itself is missing. A few months ago, I walked along the old Sac Northern ROW between Florence and the Broadway Terrace onramp right through the construction project (the fence on the south side had been knocked down) — but wasn’t able to make it all the way to Broadway Terrace because we belatedly discovered there was a security guard in a car parked at the north end.
Hi, I really like your blog!! Trying to learn some amateur geology to make the most of my near daily trips to the East Bay Regional Parks. I was curious about a rock formation in Redwood Regional Park, above the West Ridge Trail, between the Skyline Gate and Waterloo Staging area. It is a big formation on the upside of the trail. Do you know anything about it? Also, I found a cool looking rock, and wondered if it was a fossil. Not sure how to post the photo here. Thanks!! Any info is appreciated!
Hard to say, Debby. I haven’t been on that trail, but it goes through Redwood Formation sandstone and a younger unit of sandstone/mudstone. As for a photo, if you’ve posted it anywhere on the web, you can link to it here using the “img” tool.
One more comment; I recently spoke to the owners of a bunch of lots along the missing section of Sheridan, and they said there was no slide in this location — the road was apparently never built because of the slope. They reviewed City records and hired engineers and others to investigate the site before drawing that conclusion.