Archive for the ‘other’ Category


7 July 2010

As you explore Oakland, you come upon places where something has been erased and not yet replaced.

oakland hills fire

The Oakland Hills fire of October 1991 left these, the first on Acacia Avenue and the other two on Roble Road.

oakland hills fire

There must be reasons for each of these remaining ruins after almost twenty years. But here they are, some quite public and others in quiet privacy. People pass and pay them no mind. Another few decades and the traces might be gone.

oakland hills fire

I got an odd request last year: Henry K. Lee, author of Presumed Dead, asked me to visit the spot in the Oakland Hills where a notorious murderer put the body of his victim. He wanted to know how a geologist would describe the ground there. It was shale, crumbling and easily dug. The place was shrouded in oak woods, but everyday life was within earshot: lawn equipment whining, bicyclists conversing, dogs. The site—which I will not call a grave—was still being visited. But its traces should be left to vanish.

Oakland geography

8 June 2010

I don’t always poke around Oakland’s innards, its rocks and landforms and geologic history. Most of the time, I actually just enjoy the place.

lake merritt

Geography is what geology, climate, history and culture all add up to. Round Top and the ancient volcano it embodies, the hills and the sea air riding up their flanks are merely the stage for Oakland’s beautiful humanity. It is a magnificent arena, where you can see people from every part of the world in one place.

I seem to have caught up with my long backlog of photos and topics. It’s time to get outside again. What questions about Oakland’s geology are on your minds?

Drains to bay, an Earth Day message

22 April 2010

earth day

Some things are as obvious as gravity: Here’s the drain. There’s the bay. The geologist knows this so well that it never needs to be stated. The earliest thinkers of modern geology, as far back as Nicolas Steno in the 1600s at least, recognized that rocks arise from the everyday process of mud washing downstream to the sea. The signs are obvious in the petrified ripple and current marks, the fossilized sea creatures and the sandstones as clean as the stuff of beaches. “Drains to bay” might as well be written on the geologist’s coat of arms.

The rest of us need occasional reminders. Many of us never gave it a moment’s thought, probably those same Oaklanders who think that bears live in the woods up on Skyline. Earth Day is for them, the ignorant. Ignorant people are not bad people. Indeed, they’re only selectively ignorant, in that they don’t know something I consider important. Surely I’m just as ignorant in terms of what they care about. Anyway, “drains to bay” is a good start and it needs to be pointed out everywhere, even here where it’s obvious on Embarcadero East at the mouth of 14th Street Creek.

Earth Day, too, should always point out the basics. The rest of the year is for learning more and for putting knowledge into daily action—for Earth Life.

“Drains to bay” means that what we throw away doesn’t go away, any more than the ancient ripples and prehistoric creatures are totally lost.

The big rock show

7 March 2010

Sometimes I go out of town. Today I visited the annual show of the Mineral and Gem Society of Castro Valley, held down in Newark this year. For me, coming from the geological side of things, it’s dazzling kind of place.

mineral show

The hall was full of families, because there’s something for everybody at a show like this: raw materials and tools for the hobbyist, jewelry for those who wear accessories, fossils for the nerds, shiny pebbles for the young ones, specimens for the mineral collectors. They had a complete cave bear skeleton on display. Boulders and slabs of jade. Crystal spheres. And far-out stuff like the ultraviolet mineral collectors’ hall.

fluorescent minerals

All the light in this photo is fluorescence, including the scorpion on the left. These are from the collection of Lee McIlvaine, of San Leandro. I got a cool keychain blacklight for five bucks. You never know what you’ll find in the field.

Creek mouths

7 February 2010

Down at the Martin Luther King Shoreline Regional Park, three creeks debouch into San Leandro Bay. I already talked about San Leandro Creek; the other two are Lion Creek, below (more about it here and here), and Elmhurst Creek, bottom.

lion creek

elmhurst creek

Maybe with all our recent rain, they carried some sediment down to the bay, but probably not. Today both creeks are culverted to within an inch of their lives.

The trout ladder

25 October 2009

rainbow trout

The original rainbow trout come from Oakland; did you know that? The species Salmo iridia was first described, in 1855, from San Leandro Creek. Redwood Creek is a branch of San Leandro Creek that still contains good spawning grounds for rainbow trout, and this nicely maintained fish ladder is here to help them upstream.

The rainbow trout has been spread all over the world, of course. This wasn’t the only locality in the Coast Ranges they came from. The Oakland fish aren’t superior to other local strains. Their only distinction is artificial: they’re merely the first to come to scientific attention. Naturalists name species simply by picking an individual and describing it in detail in the literature. It’s arbitrary, but the only way to begin.

That’s as arbitrary as the creationist’s crude notion that the species is simply something uttered by God and named by Adam. Creationists don’t care to ask why populations vary in their genetic makeup—or if they do they regard it as the necessary decay from perfection of all earthly things. Variation is useless in their theory. But to naturalists, the reality of the species includes precisely the variation that the creationist downplays. Variation is the first rung in the ladder of evidence showing how the tree of life fits together as the result of evolution. The creationist’s interest in that project is only to suppress it.

Today we lump Salmo iridia as a subspecies under the larger species Oncorhynchus mykiss. Maybe God isn’t clear, or maybe our ideas need work. Maybe both statements mean the same thing.

Suiseki time again

12 June 2009

I brought up the topic of suiseki last summer, and now it’s that time again. This weekend, Saturday and Sunday, is the annual suiseki show at the Lakeside Garden Center from 10 to 5, no charge.


This was one of the stones on display at the 2005 show. It’s part of my gallery of Earth art on, too.

Unfortunately I must miss this show. Fortunately, I will be touring the gold mines of the Sierra foothills instead.


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