Lately I’ve been going through my bookshelf and revisiting some memorable titles by and about geology, from the 1830s to today. Today I want to share three standout books of particular relevance to Oakland readers, all by the late Philip L. Fradkin (1935-2012). They constitute his “earthquake trilogy,” published between 1998 and 2005. They all concern our particular place between the Pacific and North America plates. They’ve stuck in my mind for decades and still inform my approach in this blog. Fradkin offered this explanation of the trilogy on his former website: As a journalist and residen ..read more

Remillard Park is one of Berkeley’s “rock parks,” but it’s very different from its fellow rock parks, some of which I’ve written about (like here and here). People have urged me to check it out — not that I need urging — and last week I found the time to give it a close look. The park preserves an old landmark of the Berkeley hills called Pinnacle Rock. It sits uphill from Cragmont Rock, which is typical Northbrae Rhyolite like the stuff in the other rock parks. We’re lucky that in 1861, the eminent photographer Carleton Watkins was hired to record landmarks in what remained of the San Antoni ..read more

Wedged between Oakland and Berkeley, little Emeryville is situated entirely on the flats where Temescal Creek, mostly buried, meets the Bay. Its eastern tip is about 55 feet above sea level; its native material has nothing in it bigger than a pebble. Pink, artificial fill; Qhb, basin deposits (mostly clay); Qhl, levee deposits (mostly silt); Qhaf, alluvium (mostly sand) The city perforce is all about the human presence; every square meter is under control. Besides the railroad and the freeway, buildings dominate the views along its streets: from east to west they’re mixed bungalows and Victor ..read more

There are two great gardens in the hills above Berkeley. The UC Berkeley Botanical Garden, in Strawberry Canyon above the campus, has plants from all over the world. I’m here to talk about the other one: the Regional Parks Botanic Garden. It’s in Wildcat Canyon, hidden over the ridge in Tilden Regional Park, and focuses exclusively on California. OK, the one garden is “botanical” and the other is “botanic.” In my mind the difference is subtle but noteworthy, like the distinction between “geological” and “geologic”: the shorter word has an air-quotes connotation of something scientific or schol ..read more

Over the years, I’ve written up a few side trips from various BART stations (El Cerrito, Lafayette and Warm Springs here and Hayward, 16th/Mission and the phantom Irvington station elsewhere). Time for a look at Concord, where one of our major faults runs right through town. At our latitude, the Concord fault marks the inner edge of the wide boundary zone between the Pacific and North America tectonic plates. The two plates rub past each other at a total rate of about 50 millimeters a year. About half of that motion takes place on the San Andreas fault and smaller fractions on the Hayward, San ..read more

This post looks past the Tertiary Period into the previous slug of geologic time, the Mesozoic Era. To geologists, our oldest rocks are not that old. To us a million years, as I said in Deep Oakland, is like the tick of a clock, and while Oakland rocks go back about 165 ticks there are rocks on Earth about twenty-five times older. Oakland is typical of the whole Bay area in its relative youth. Oakland’s oldest rocks — the Leona volcanics and the Franciscan melange — have no fossils worth speaking of. Our oldest rocks that could preserve fossils belong to the Great Valley Sequence, a huge thick ..read more

My last post was about Oakland’s youngest fossils, which are unmineralized bones found in Pleistocene sediments. Our older ones are traditional fossils — remains encased in rock. They naturally fall into two different segments of geologic time, the Tertiary period (this post) and the Mesozoic Era (next post). “Tertiary” is an old, unofficial name for the time between the dinosaurs’ demise and the beginning of the ice ages — the archaic part of the Age of Mammals. Geologists find it useful in the American West, where rocks of that age range (66 to 2.6 million years ago) are bountifully exposed ..read more

My book Deep Oakland is based on the huge variety of rocks and geologic features we have in this town and near it. In that way Oakland is like California, a state of fantastic geological variety. Indeed, in Oakland you can find more rock types than in any other city in America. That variety of rocks is intriguing. Does Oakland, like California, have some cool minerals? Do we have any gemstones? The answer to both is “Yes, sort of.” Oakland has no minerals of precious value except conceivably a sniff of gold. The classic Gold Rush skipped the East Bay; all anyone noticed along the front of the ..read more

The other day I strolled the length of Center Street, a kilometer of pure classic century-old West Oakland residences. Along the way I passed Cypress Freeway Memorial Park, the park at Mandela and 14th that commemorates the 1989 earthquake. This is the back end―that is, at Center and 13th Streets. I was stopped in my tracks by this scene. The undulations in the ground, representing the seismic surface waves that shook down the freeway, extend all the way to this end. The uneven land nevertheless has space for a well-organized community of unhoused people, augmented by a row of RVs on 13th Str ..read more

I led a walk around the headwaters of Lion Creek this weekend, visiting the Lincoln Square serpentine and landslide, the Alma Mine and Crusher Quarry sites, and the Hayward fault over at 39th Avenue (one of the seven stations). One of the best parts of the trip was revisiting the creek at McCrea Memorial Park and Oakland’s casting pools, an unsung civic amenity for our fly-fishing population. The casting pools were constructed in the late 1950s. The land was part of the city’s Leona Park, which extended from here across Mountain Boulevard and up Horseshoe Creek. To all appearances, this site ..read more