Archive for the ‘oakland stone’ Category

A real old-timer

15 April 2012

Mountain View Cemetery is a fun place for geology. Not only are there the untouched hillsides and the knockers of local bedrock, but the monuments themselves are displays of fine stone from around the world. On my last visit, though, this one caught my eye.

morton gneiss

It’s an example of the oldest stone in the United States, the Morton Gneiss from southwestern Minnesota. I mentioned it a few weeks ago in a KQED Quest Science Blogs post before finding this specimen. Touching it will put you in contact with something 3,524 million years old, more than three-fourths of the planet’s age.

Let me take this opportunity to plug Michael Colbruno’s blog about the people in the cemetery. He calls it “Lives of the Dead: Mountain View Cemetery in Oakland,” but I still think of it by its original (non-SEO-friendly) name “Mountain View People.”

Slate fountain

23 November 2011

Here’s a nice piece of stonework on upper Lakeshore Avenue.

slate fountain

It’s a pit lined with picturesque cobbles and rimmed with gray slate flagstones. A large slate boulder is mounted in the center, and a fountain trickles off a smaller slate stone over the boulder, cascading into the pit with a delightful sound. Thanks for the gift to passers-by.

Sidewalk weathering

18 October 2011

I look at sidewalks more closely than most people. It has little to do with geology, though—it’s just part of my hobby. But sidewalks do have geological lessons in them. Consider this sidewalk on the north side of upper Broadway near Lake Temescal.

sidewalk weathering

It has a series of light-colored wedges along the fence, on the uphill side. As you might guess, they reflect the pattern of the rainfall and its drainage. Fresh concrete is poured and then caressed with trowels as it begins to cure. This treatment pushes the larger particles of aggregate under the surface and creates a smooth finished surface composed of fine particles and cement. But the surface tends to weather off, partly because the surface is hard to keep moist for proper curing. The imperfectly cured material is prone to attack by rainwater, which is a mild acid. As rain and wind work into the surface, green things both microscopic and visible colonize the rough spots. These turn up the acid attack with exceptionally high CO2 levels similar to those in soils, along with humic acids produced by plant tissues. With time, the crisp white walkway turns rough, variegated—and beautiful, akin to natural stone.

sidewalk weathering

Woodminster Cascades

16 September 2011

Oakland is blessed with excellent stonework dating from the Depression-era Works Progress Administration or WPA. When the WPA got together with Park Superintendent William Mott to build Woodminster, in 1940, an experienced cadre of artisans built its elegant features with a sure hand.


I should know more about the stone, but I don’t. It’s very similar to the stone used at Lake Temescal and the East Bay Botanic Garden in Tilden Park. It likely came from the Leona Quarry.

While you’re there, be sure to admire the amphitheater’s Deco concrete. And keep your eye open for WPA concrete in Oakland’s sidewalks and gutters. I’ve seen WPA marks from 1939, 1940 and 1941. This investment in public works has endured for more than 70 years.

Oakland stone landmarks: Middle Harbor Park’s replica training wall

5 July 2011

Even before I knew what it really was, this short pier at Middle Harbor Park stood out.

middle harbor pier

This is clearly not a typical groin or breakwater, something that is dumped into place, but a carefully laid work of drystone masonry. It feels absolutely solid to walk upon. And then there are the rocks in it, a rich assortment of large and pristine Bay area specimens. There are tuffs composed of volcanic pyroclastic flows,


colorfully metamorphosed volcanics,


slickensided serpentinites,


and other metamorphics whose colors could inspire a fabric maker.

jacob's coat

Also sandstones and even a few ringers of Sierran granitic rocks, perhaps from the old quarries of the Rocklin area. But it’s not typical of a modern marine rockwork—those use stone trucked in from a single quarry to save money and control the quality.

An interpretive sign explains that it’s a replica of the old “training wall” on the north side of the shipping lane to Oakland Inner Harbor, where the signature gantries load and unload big freighters. Training walls are jetties designed to turn a shipping channel into a flume during ebb tide, keeping the bottom clear of mud. The walls were built around the 1880s, using shoreline quarries around the Bay and shipping the rock here by barge. That explains the unique variety and distinctive regionality of the material.

The north training wall was removed when the shipping lane was enlarged in 2001, but they saved some of the stones. Masons installed them over a core of rubble, and here they are. The south training wall remains in place.

Oakland stone landmarks: McElroy Fountain

29 June 2011

Oakland has not only rocks, but also stone to admire. The grand McElroy Fountain of Lakeside Park, newly refurbished and 100 years old this year, displays monumental marble to advantage.

mcelroy fountain

Here’s a page from Annalee Allen’s book Oakland about the fountain and its namesake, a Flickr page with some discussion of the project, and a set of closeups of the (wildly misinterpreted) bronze panels by Douglas Tilden around the fountain depicting stages of life.

I didn’t find any information about the stone, but this grade of marble was easily available from domestic and foreign sources in 1911. Oakland was a big stoneworking town with many skilled European craftsmen, a major regional cemetery, a booming construction industry and good freight service by rail and sea.


22 September 2010

A few places in Oakland feature these sandstone blocks. Two I can think of immediately are on Lakeshore Avenue, including this one.

sandstone blocks

I always wonder whether the stones were salvaged from somewhere else, like Andy Goldsworthy’s wonderful “Stone River” on the Stanford campus. They have tool marks on them, and I don’t know much about stonecarving tools, but I’ll bet they haven’t changed in centuries. These stones echo the most ancient practices of civilization, in which building stones were recycled again and again without regard to the structures they previously gave life to. The stones were precious in bulk rather than as individuals, the way that gold bullion is precious.

These stones always remind me, every time I see them, of one of William Randolph Hearst’s greatest follies. He purchased an ancient chapter house, built in Spain by Cistercian monks in 1190, and shipped it to California as disassembled stones. He never got around to putting them back together again, and as I recall the story, they sat in a pile somewhere in Golden Gate Park. (That’s probably an exaggeration, but who knows?) Now those stones were precious in the way that old gold coinage is precious—they embody history. These days we are a sentimental people, and the Spanish stones have a bit of holiness in them, as if the monks’ prayers had saturated them. Scattering them on the ground in a strange land is an affront to their previous owners.

That’s why I loved today’s Tribune column by beer writer Jay Brooks. A California branch of the Cistercians, the Abbey of New Clairvaux north of Chico, has acquired the stones and plans to reassemble the chapter house using the profits from a series of Trappist-style beers to be made by Sierra Nevada Brewing next year. The Trappists are the order of monks that include the Cistercians, and they’re famous for brewing Belgium’s greatest beers. That’s worth a toast.


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