John McPhee's "Assembling California" is a book that defies categorization. Is it about geology? History? Maybe California culture? Or perhaps some cosmic statement about the infirmity of terra firma and the inevitability of catastrophic changes in the environment?
It is all of the above. McPhee has constructed an epic story with rocks and shifting seas as the main characters. The reader comes to feel a certain warmth for the ophiolitic sequence, so misunderstood by puny geologists. Even the main human hero, who tries nobly to speak the truth about Earth's structural history, is playing the role of scribe, secondary to the role of lava flows, tectonic plates, and colliding land masses. Any book that can make 4 billion years of migrating planetary crust seem interesting deserves a "+".
"Assembling California" is mainly about the origins of the territory we now call California. The west coast of North America used to be somewhere around Colorado, but over a few hundred million years, several land masses crashed into that coast, accreting into California (and raising the Rockies and the Coastal ranges). But McPhee takes the tale much wider.
We learn about the theory of plate tectonics, how new ocean floor spills up from the mantle in deep crevices, then spreads outward. As plates undercut each other and scrape together, mountains are raised with predictable sequences of rock types that are conveniently revealed for geologists in our very human roadcuts. We learn how metals form in thin rivulets between particular kinds of rock when subjected to the right conditions, which leads to fascinating side tracks about the history of the Gold Rush in California and the copper mines of Cyprus. We learn about the history of the theory of plate tectonics. We learn about how San Francisco's geology is so heterogenous and jumbled that it is called a "melange."
I'm sure it is no accident that the book itself resembles a geological creation. McPhee often defines words the second time he uses them, so the reader gradually learns to press on in the face of terminology. Like in examining a roadcut, the pattern eventually becomes clear. Also, the nonlinear writing--which jumps around over a 20-year period that McPhee worked with a geologist as well as spans millennia of human and pre-human history-- is reminiscent of the churning that goes on during tectonic collisions. Culture is upended and laid bare on a mountainside for examination.
An overarching theme is the mind-bending difference between human time and geologic time. Continents shift about at speeds of centimeters per year, and even at this pace, the whole world has reconfigured itself at least twice. It's impossible to imagine this sort of time, and yet, the human and geologic worlds do meet-- during earthquakes. Fittingly, "Assembling California" ends with a (dare I say) moving description of the 1989 earthquake centered near Santa Cruz. Since the rocks have been built up as the heroes of the epic, the event has an odd tone of normalcy amidst the human chaos it causes. The reader is left with little doubt that another quake will occur, proably sooner rather than later, and it too will be perfectly normal. That's what the Earth does because it is busily reconfiguring itself.
This book won't appeal to everyone, and I think it started a bit slowly before I synched with McPhee's lulling yet slightly wry writing voice. But it's a unique book; you won't read another one in quite this style (unless you read another McPhee). And if you're interested in exploring the roadcuts along California's Route 80, the melange of San Fran's Nob Hill, or the imposing profile of Mussel Rock, there is no better preparation for the cultural and geological journey you would be going on.
Copyright © Kim Allen 2000
