Blog Profile / Oakland Geology

Filed Under:Academics / Geology
Posts on Regator:349
Posts / Week:0.7
Archived Since:March 16, 2008

Blog Post Archive

Oakland geology ramble 5: Grass Valley

Over the last few weeks I’ve been exploring the remote land just east of Skyline Boulevard, over the city line in Anthony Chabot Regional Park. Time to show you some of the charming features of Grass Valley, seen here from Redwood Ridge near the Parkridge land bridge. In classic Geology Ramble style, this walk (a […]

A new kind of shoreline

Rising sea level is a threat to the Bay area. Already, king tides are flooding the levees and seawalls built for the last century’s ocean. I touched upon this topic a few weeks ago with my proposed walk around Lake Merritt in 2100, assuming that the Bay will be a couple meters higher than today. […]

Redwood Ridge and the Parkridge land bridge

Redwood Ridge is a name I made up to keep things straight. Let’s start with the part of the USGS topo map showing the south end of Oakland’s redwood country. Redwood Ridge is just east of Skyline Ridge (another name I made up), which starts where Joaquin Miller Road meets Skyline and extends to Lake […]

Care and grooming of rocks and outcrops

Photographers know that everything about a great shot depends on how you set it up. As I capture images of geological subjects, part of the setup involves prepping the model. Often it’s just a matter of removing a few stray twigs to get a decent picture, like these serpentine stream cobbles in Joaquin Miller Park. […]

Tour of the Fan: Lobe 3

This post takes a look at lobe 3 of the Fan. To orient you as we start, here’s where lobe 3 fits in the bigger picture on the geologic map. This is the best time of year to walk around the Fan, in the Oakland midlands. When the trees are bare you can see farther […]

A walk around Lake Merritt in 2100, after sea-level rise

Everybody walks around Lake Merritt. I do it all the time. But I got the wacky idea of a walk that circles the lake without “touching” it — sort of a “floor is molten lava” version — and pedestrian paths count. Here’s what that would look like. That’s a fun walk through some fine neighborhoods, […]

Tour of the Fan: Lobe 6

The ancient alluvial fan of central Oakland consists of eight lobes. To refresh your memory since the tour of Lobe 4, here they are labeled on the geologic map. This week I want to show you Lobe 6. The dominant feature of this lobe is the hill on which the Maxwell Park neighborhood was developed […]

The St. James Drive roadcut

Recent work in far east Piedmont has exposed some excellent bedrock worth a close inspection. Because the town government won’t put an interpretive sign there, this post will have to do. To my knowledge, there are only two sites of powerline towers in Piedmont, one at the mouth of Estates Drive and the other at […]

Geologizing on the 33 bus line

My geologizing habits are unusual: being self-employed and semiretired, I go out on weekdays, when everyone else is busy and I have the landscape to myself. Moreover, most of my outings around Oakland are on foot, with the help of the Citymapper phone app and all manner of public transit, which I’ve praised before. In […]

The Dunn-Spring Quarry, north Berkeley

Glendale-La Loma Park, a little ballfield/playground complex in the north Berkeley hills on La Loma Road, is a repurposed quarry that’s had a true Berkeley history. The original quarry, operated by J. J. Dunn, appears to date from 1892. John J. Dunn, a Canadian immigrant born in 1839, was a major contractor in California building […]

The Hillside School and the Hayward fault

It was a most enjoyable hike that I led on Saturday for the Berkeley Path Wanderers Association, wandering for 3-plus miles in the city’s wonderful rock parks and along the Hayward fault. As usual, visiting the fault has its troubling side, and here I couldn’t resist the implications of this splendid building, the old Hillside […]

Bedrock in the headwaters of Trestle Glen Creek

Surprisingly, the town of Piedmont has its share of woodland trails — well they’re paved sidewalks, but they’re unused, covered with duff and overhung with untended shrubbery. On a weekday afternoon, you can walk quietly on miles of these soft paths and encounter only a handful of property workers. It’s in that spirit that I […]

Grotto Rock Park

In preparation for the 4-mile walk I’m leading on 18 November for the Berkeley Path Wanderers, I’ve been visiting some of the unique and wonderful rock parks in north Berkeley. Grotto Rock Park will not be on the route, so I’ll feature it here. It’s a little park on Santa Barbara Road at Indian Rock […]

Orinda’s 1204 Hill

As far as I know this hill has no name, but it’s a highly visible part of Orinda. You pass it on Route 24 between the Wilder exit and downtown, as seen in this Google Maps perspective view. The USGS topo maps give it an elevation of 1204 feet, so I’ll call it 1204 Hill. […]

Serpentine and pebbledash on Broadway

The intersection of Broadway and 20th Street features strong buildings on all four corners. We all know the I. Magnin building (built 1930) and the Capwell (Sears/Uptown Station) building (built 1929) facing it. Across Broadway, we have the metal-clad urban spaceship of the Kaiser Permanente Division of Research building (built 1982) and finally the dark […]

Earthquake apps and post-quake observations

Seems like disaster is in the air every October. This year the catastrophe is wildfire in the North Bay, bringing up memories of our own turn in the line of fire this very week in 1991. Yesterday the local paper published an article by Seung Lee that explicitly linked the October fires of 2017 to […]

Post 500

The experts say the greenhouse gases we’ve put in the atmosphere will affect global climate for the next several centuries. Where will we be 500 years from now, once this pulse of carbon dioxide has been drawn down by the seas and soil? What will the post 500 world look like? I’m fond of talking […]

Twenty Oakland rock types in a 30-mile drive

As far as I can tell, Oakland has more rock types within its boundaries than any other city in America. When I added them up for a talk I gave at East Bay Nerd Nite, I counted more than 25, from limestone to blueschist. This 30-mile road trip will take you to most of them, […]

The highest point in Oakland

I have believed — and what’s worse, repeated — that Oakland’s highest point is Grizzly Peak. In fact, the highest point within the city limits is Chaparral Peak, an eminence so subtle you can barely tell it’s there. Let’s look at the 1959 topo map of the high Berkeley Hills. Everything south of the county […]

Sibley sights: Lapilli tuff

Sibley Volcanic Regional Preserve is the site of a small volcanic center that was last active about 10 million years ago. After it fizzled out, the whole thing was gradually buried in younger sediment. Within the last few million years, the action of the Hayward fault squeezed, folded and uplifted this sequence of rocks and […]

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