California is one of the newest parts of North America. Not long ago—just a couple hundred million years ago, which isn’t much on a geologic timescale—North America ended, roughly, in Nevada. To the west of Nevada was the Pacific Ocean, and in it, a great chain of islands that no longer exists. The island chain was inching its way east, towards Nevada’s Pacific coast. The islands crashed into North America, in succession, and coalesced into California. They left tectonic fissures—fault lines—as a reminder of their former independence. To understand what the islands looked like, pre-crash, “just look at a map of the southwest Pacific—look at the relationship between Australia and Indonesia right now.”
Those words come from Eldridge Moores, fourth in the line of geologists touring with John McPhee across the United States for McPhee’s five-part, Pulitzer-winning geological history of the United States, Annals of the Former World. Moores, we discover in the fourth installment Assembling California, comes from California rock stock; his father was a gold-miner near the Nevada border. “It was backbreaking work,” said Moores of his father’s bootstrap mining, “but my father had a tough back.”
Not long after the Second World War, the adolescent Moores went to work in his father’s mine, pushing mine-carts and sorting ore by hand. When war surplus was being sold off, Moores’s father had bought a gigantic 10-wheeler truck that could haul 12 tons of ore down the mountain into which his mineshaft was sunk. Moores learned how to drive in that truck, on the mine’s five-mile access road (which had been engineered and built by his father). “Not the least of its features was a railless plunge on the outboard side,” writes McPhee. “As [Moores] practiced, he dragged a road grader behind the truck. His father was back there, working the grader.” Moores recalls, “I was one scared little teen-ager.”
Perhaps unsurprisingly, Moores had little interest in following his father’s career path. In fact, like a character in a Patrick O’Brian novel, Moores real passion was his cello. But he went to the top university in his neck of the woods, which was light-on-music Caltech. At Caltech, his natural propensity for geology couldn’t be ignored. He became one of the top geo-men in the west, and he gives McPhee fascinating accounts of the Earth’s perpetual tectonic motion, which fills up the bulk of Assembling California: “Not long ago, Japan was attached to Asia. It drifted away. Japan is coming toward North America one centimeter a year. It may be part of Alaska in eight hundred million years.” And Japan may not be coming alone; Moores suspects that Australia may “pick up the Philippines and every intervening island and then go after Japan on Japan’s way east.”
Surprisingly, this would not atypical. “Southern Florida,” says Moores, “is a piece of Africa which was left behind when the Atlantic opened up.” That’s not all.
But nowhere is the slow-motion crash of continents clearer than in California, which is why once or twice a year there’s a major new story predicting “the big one” in the Bay Area. Is the big one coming soon? “Probably,” say the geologists. (“Probably,” say the equations.”)
But read the book and see for yourself. It’s a masterpiece.
Joshua Gelernter is a writer in Connecticut.
