Archive for the ‘Oakland geology views’ Category

The marine terrace of Clinton, lengthwise

20 March 2017

A few years back I showed you a view across the flat marine terrace where the old town of Clinton once sat, back in the 1850s. To really get a sense of it, walk the length of the terrace some time. Here it is on the geologic map, marked “Qmt.”

The photos below (1000 pixels) were taken last week at the locations of the two blue asterisks.

First we have a view off the edge of the terrace at E. 15th Street and 22nd Avenue. At barely 40 feet elevation, the view is quite extensive. That’s the former Catucci building in the left middle.

East 15th Street, a residential street running between International (E. 14th) and Foothill (E. 16th) Boulevards, is a pleasant walk on this extremely level geomorphic feature. Look northeast as you go and note the abruptness of the terrace’s inner edge. That was where the sea used to lap up against the Fan during the last major interglacial, about 125,000 years ago.

At the other end of the terrace, at 3rd Street and Foothill, the land turns down toward Lake Merritt (and the hospitable Portal).

But turn around to see just how flat this thing is.

The two stream valleys that interrupt it, at 14th and 23rd Avenues, are like canyons by comparison.

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Siesta Valley and the De Laveaga Trail

2 January 2017

Last week I attempted the Rockridge-to-Orinda ramble by a northern route. Was strenuous, but it got me into Siesta Valley, a place I’ve had my eye on for years, for the first time. At this time of year the sun is so low that the light is terrific.

First came the climb up Tunnel and Caldecott Roads, then through Hiller Highlands up to Grizzly Peak Boulevard, a good 1200 feet higher, then down across the Fish Ranch/Claremont saddle, where it looked like this.

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That’s Gudde Ridge, in Sibley Volcanic Preserve, with Round Top on the horizon. The stairsteps in the rock are the huge roadcut for Route 24. Siesta Valley is to my left, over the ridge.

Siesta Valley is watershed land under the control of East Bay MUD, so I made sure to have my hiking permit with me. Not a soul was around, but it’s a good habit. The De Laveaga Trail runs from the top of the valley, at the Scotts Peak Trailhead, along the valley’s north flank. (It’s named for one of Orinda’s founding families — see the comments.) I took the wrong way, going straight down the valley floor on the dirt extension of Wilder Road, which leads to the back side of the Cal Shakespeare center. That meant a steep descent and subsequent climb of a few hundred feet on a pretty wet road, but I saw some bedrock of the Siesta Formation I’d otherwise have missed.

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That included this fine chunk of freshwater limestone, all of which fizzed nicely in acid, just like it should.

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Once I gained the De Laveaga Trail, the views opened up. The basalt flows of the Moraga Formation crop out well here.

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This view looks down the Siesta Valley to its continuation as Wilder Valley, across the freeway in Orinda.

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Siesta Valley is very quiet. City noise and freeway noise are kept out by the contours of the land, and on a lazy weekday afternoon I could see myself having a nice nap.

The trail leads up and over the east wall of the valley at about 1500 feet elevation, then it’s a steep 1000-foot plunge down to Orinda. This is the view north. The cattle pond is there because cattle graze these slopes.

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The sun sets so early here that it gets cold at night. Shaded puddles stayed ice-covered all that day.

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The winter haze obscured the Sierra, but not Mount Diablo and the Lamorinda hills.

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As I raced the sunset, downtown Orinda looked inviting. This is a harsh downhill, though. Uphill would be worse, I think. Nothing to do but try it sometime.

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The verdict: Siesta Valley is a challenge to reach on foot, but that’s your only choice as vehicles of all kinds are forbidden on EBMUD land. It’s an obscure piece of land that requires a permit, but it’s a gorgeous place. With rocks!

2016: Pictures from a good year

26 December 2016

Here are some nice views I enjoyed during the year. These shots are meant for clicking through to see at full size.

In January, I said goodbye to the old Bay Bridge and looked forward to the day when the new bridge offers a superb platform for viewing the Oakland skyline.

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In February, I was captivated by the chaparral high on the face of the Leona Hills.

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In March, I got a good look at Mount Diablo from Wilton Drive, on the edge of Redwood Regional Park.

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In April I was transfixed by the view south from Fairmont Ridge to the hills back of Hayward, an area I have yet to visit.

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I took great pleasure in tramping out my first three “geology rambles” this year. Not every photo was geologically relevant, but this moment from the July day when I first envisioned ramble 3 was too charming to forget.

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And several times this year, I’ve gone to Devil’s Slide to dispose of rocks by throwing them into the boiling sea. But the views in the other direction are stupendous.

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I have enjoyed the hell out of geologizing this year.

Changes coming to Mountain View Cemetery’s landscape

4 July 2016

Mountain View Cemetery is one of Oakland’s great civic ornaments for several reasons: its gravestones and tombs commemorate generations of historically important Bay Areans, and its plan was Frederick Law Olmsted’s second significant large-scale project in landscape design after New York’s Central Park. It’s a fine piece of open space that’s used by many different groups of people.

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I think of the cemetery as a great civic ornament for two special reasons of my own. First, it’s a superb display of Oakland’s natural landscape as the first settlers knew it.

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Second, it’s got some great exposures of Franciscan melange, the mixture of rock types that was created by the tectonic collision between the North America and Farallon plates about 90 million years ago.

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The cemetery’s operators are planning to reoccupy and develop the highest part of the grounds, the two heights in this photo taken from the Catholic cemetery next door.

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Here’s the view from up there. The cemetery proposes putting in roads and formal structures in the foreground and up on the hill beyond the fence, behind the greensward.

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The goal is to accommodate about 1500 more grave plots. A lot of dirt and rock will be dug up and moved around. The plan talks of building up the hilltop and tilting it toward the bay for better views.

The city’s master page for the proposed work is here. The draft environmental impact report is there, plus info on two upcoming hearings (July 11 for the Landmarks Preservation Board, July 20 for the Planning Commission). This month is the public’s most influential time window.

The land beyond the fence is a special bit of countryside . . .

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. . . with its own constituency.

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It also has its share of rock outcrops. To me these are precious things. Most outcrops in these hills either were blown up during development or are locked up in people’s back yards.

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I’m still thinking about what I want to tell the city. But my basic concerns are that the natural character of the land — its contours and vegetation — be respected and preserved as much as practicable. The project will affect a landmark that hundreds of thousands of people enjoy from their own windows and yards.

Olmsted considered these hills the essential setting for the elegant, transformative parkland he planned here in 1863. Mountain View was, and remains, an icon of the City Beautiful movement and a destination for landscape architects everywhere. It and Stanford University (designed in 1888) are the only major Olmsted projects in the Bay area.

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This amazing cemetery is Oakland’s cemetery. Let’s speak up to help keep it as beautiful as possible.