Archive for April, 2010

Sunset Trail

27 April 2010

Sunset Trail is one of Oakland’s obscurest thoroughfares, if you can call it that. It’s a footpath connecting Eucalyptus Path, in Oakland’s Claremont neighborhood, and Willow Walk, just over the Berkeley line. Obscure though it is, when I walked it the other day I met two other pedestrians as well as this fine knocker.

sunset trail knocker

I imagine it gets its name from spots like this back yard (click it for a larger version).

sunset trail

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.

Oakland’s crown jewel(s)

20 April 2010

claremont canyon

The Tribune had a few letters the other day about Knowland Park, the piece of land that includes the Oakland Zoo, that referred to it as Oakland’s crown jewel. The coincidence of that phrase in multiple letters strikes me as a talking point, not a settled fact. Although I do agree that if Oakland has a crown it’s the hills, surely that crown has a whole string of jewels. Case in point, Claremont Canyon, seen here from the top of Garber Park on Alvarado Road last week (click the photo for a 1000×800 version). Round Top would be another, as would Redwood Peak and Chabot Reservoir and Serpentine Prairie and Huckleberry and that nameless little hill above the south end of Grizzly Peak Road, totally unsung, from which you have a commanding view of the world itself. And, I’ll grant you, Knowland Park too.

Redwood Canyon Formation

8 April 2010

The Redwood Canyon Formation sits above the Shephard Creek Formation in what’s called a conformable relationship, indicating that the two units represent a continuous span of time. The difference between the two formations is that where the Shephard Creek is fine-grained, the Redwood Canyon Formation is coarse, consisting mostly of wacke (dirty sandstone) and some siltstone. Neither of these rock types is rich in clay, whereas the mudstone and shale of the Shephard Creek Formation are pretty much defined by it.

redwood canyon formation

Again, this unit dates from the Campanian Age of the Late Cretaceous Epoch, which extends from 83 to 71 million years ago. And again, it’s steeply tilted by activity along the nearby Hayward fault, although it was originally laid down in flat-lying beds. It holds up steeper slopes in Shepherd Canyon, being a stronger rock than the underlying unit. Elsewhere, the Redwood Canyon Formation turns into the Pinehurst Shale going upsection, but in Shepherd Canyon that unit does not appear, having been removed by faulting.

There’s another photo from this formation here.


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