Hello Subscribers,

We all have demands on our attention; in fact, watching the phone zombies around me, “attention capitalism” seems to have us firmly in its grip. A recent opinion piece in the Los Angeles Times argues that today the problem of distraction, “the fracturing of our focus”―the ability to control one’s attention―should be a central concern of higher education. The author is J. Walter Sterling, the president of a small college in Santa Fe, and naturally he recommends “four years in our sanctuary-like mountain setting studying a great books curriculum,” but more generally I approve of his call to rise above “the thin, accelerated dopamine loop that drives almost all of our constant connectivity.”

Sterling’s advice does go beyond deep reading of great books, “especially literary fiction,” to mention attending “the complexity of natural phenomena.” That’s where I raise my affirming fist. Have you noticed lately that we live on an amazing planet?

Earth science, what I write about, is deep reading of landscapes and rocks. Earth is a great book written by matter, physics, biology and chance. When I see the signs and symbols in outcrops and landforms, what comes to mind is a favorite quote from Whitman’s “Song of Myself”: “To me the converging objects of the universe perpetually flow,/All are written to me, and I must get what the writing means.”

Have you noticed lately how beautiful everything is? Science deepens that beauty by deepening our understanding of beautiful things. And beyond that is what Nicolaus Steno, father of geology, called “most beautiful by far” to an audience in the 1660s, after the things we perceive and the things we understand: the things we do not yet comprehend. The more we know, the more there is to discover.

Events

It was a pleasure to meet a good dozen of you last month and trek together up Castle Canyon, an obscure part of Sausal Creek’s headwaters. A reminder that I’ll lead this walk again on 3 May for the Friends of Sausal Creek; if you want to join me, sign up for their mailing list because I’ll be under their sponsorship.

I’ll do the first Lake Merritt walk of the year on 26 April. I think Lake Merritt is a great setting to introduce a wide range of Deep Oakland facts and topics. Many attendees are already regular Lake Merritt walkers, and it’s always a pleasure to show them a new way to experience it. I’ll do it this year on an other-monthly basis: in June, August and October. Tickets are $10, not because I need the money but because it helps ensure that people show up. The ticket window at Eventbrite opens when this newsletter is sent out.

My own April will be eventful, starting with the annual meeting this week of the Geological Society of America’s Cordilleran Section in Sacramento. Along with UC Berkeley emeritus professor Jere Lipps, I’ll be in charge of a session of talks and posters about Lake Merritt, “jewel of Oakland,” Wednesday afternoon. I’ll give a talk on the lake’s geologic setting and present a poster on its tectonic origin. Both the poster and the slide deck use this photo as a background image, one of my favorites.

Daylong geological field trips will bracket the meeting, one to the Napa Valley and the other to the picturesque Sites/Stonyford area west of Willows.

A week later I’ll board Amtrak to Baltimore for the annual meeting of the Seismological Society of America. I’ve never been to either the city or the conference, so now’s the year for that. I expect to find many beautiful things to perceive, more to understand, and much I’ve yet to comprehend. The train ride avoids the headaches of flying east against the clock, and it will be a fine time to get some thinking done.

Book News

I have seen and held the paperback edition of Deep Oakland, fresh from the printer, and it is good. It has a different cover.

The list price will be $20, as compared to the $28 price of the hardback. The formal publication date is 6 May, but the publisher is taking preorders already. As far as I know, there will none of the promotional hoopla that went on with the first printing, just smooth sales-ing.

Look at This

I was strolling down Powell Street in Emeryville, as one does, past the beautiful brick Pirates Press building (makers of premium vinyl records and much more), and had to admire this walkway made of fragments from a stone dealer’s yard.

The outer ring of stones is larvikite, a particularly pleasing granitoid made mostly of big gleaming grains of blue labradorite feldspar. Give it close attention next time you pass by.

Q&A

Bob has been collecting and cutting “Berkeley blue” agates somewhere in the Berkeley or Oakland hills and sent some pictures of his hoard. He knew that they formed by minerals filling bubbles in the lava flows of the Moraga Formation, but he couldn’t square that with the fact that the lavas erupted on dry land and not underwater. The answer is that dry land is only dry at the very, very surface. In most places, the water table―the top of groundwater-saturated conditions―is no more than a few meters down. I replied, “You are correct that agates form in a water solution. There is always water underground, whether it’s rainwater seeping down or groundwater seeping up, and every lava flow, once it cools enough, sooner or later is permeated with water, and that’s when agates form.”

Among Bob’s photos, these ones caught my eye for different reasons.

Agate is the rockhound’s name for stones made of semitransparent, noncrystalline quartz, the mineral chalcedony. They form in a variety of ways as hot silica-bearing solutions deposit layers of chalcedony inside void spaces. Bob’s agates formed within gas bubbles in the lava beds of the Moraga Formation: in geological language, they are siliceous amygdules that filled vesicles under hydrothermal conditions. The first one, an uncut agate, shows the shape and size of the bubble. The other two, cut and polished, show the internal structure that is so appealing in agates. The straight line segments indicate the horizontal plane at the time the layer was deposited. Geologists call that a geopetal indicator, an example of a “way-up structure.” You might think that ordinary bedding in sedimentary rocks is always horizontal, but there are exceptions. The excellent Open Geology online textbook Historical Geology has a whole chapter on way-up structures.

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March Blog Posts

This month, with five Mondays, I got to slip in three posts on deepoakland.com (also known as oaklandgeology.com). In “Geologizing on the bus: The 54 line” I list a good dozen places to investigate along the route, between the Fruitvale BART station and Merritt College in the high hills. “The code of hammering” presents my seasoned advice for wielding a rock hammer―as a tool to be used as little as possible. And last, I offer two solutions to the mystery of “That orange creek in Joaquin Miller Park.”

April’s posts will come on the 14th and 28th.

As always, thanks for reading.

Andrew