This is the second half of my review of Annals of the Former World. You should read the first part here.
Wrapping up Rising from the Plains, McPhee explores the concept of ‘hot spots’. If you look at a geological map of the Pacific Ocean, you can see a chain of islands, underwater, extending from Hawaii most of the way to Asia. This is because there is an intense thrust of heat somewhere deep in the earth’s mantle — Hawaii, the Yellowstone Mountains, and portions of the Caribbean among others did not rise via plate Tectonics, but through these hot spots. The underwater islands are portions of Hawaii from the distant past. Eventually Kauai, northmost and oldest of the islands, will sink and new islands will arise southeast of Big Island and the chain will continue.
A hotspot lay under Yellowstone that conceivably traveled all the way under the US and fired Bermuda into the Atlantic.
For an extremely large percentage of the history of the world, there was no California. […] I don’t mean to suggest that California was underwater and has since come up. I mean to say that of the varied terranes and physiographic provinces that we now call California nothing whatever was there. The continent ended far to the east. Where California has come to be, there was only blue sea reaching down some miles to ocean-crustal rock.
This is a geological history of California, the newest segment of the United States. It’s also a story of settlers moving west, the doom of the Donner party, and especially the gold rush and the 49ers, a history of humanity directly triggering geologic events in a mad destructive frenzy to unearth more gold. It’s an excellent mix of history and science. As he wrote these books, McPhee learned better how to fluidly entwine the two. Like the Nevada books, my understanding was greatly enhanced by reading of areas I’ve lived/visited. It’s easy to image the miners shearing through the Sierras with high-powered hoses when you’ve actually driven by the pits they left behind.
McPhee travels with Eldridge Moores, a professor with an unlikely childhood in a tiny Arizona mining town, throughout the mountains of the Sierra Nevada and down through the central valley and over to the coastal ranges abutting San Francisco north and south. They do not remain state-side and revisit Moores’ old areas of study — Macedonia and Cyprus. Assembling California has a scope beyond the previous books, even while focusing on one state. The newness of California is fascinating and allows us to imagine how many other areas of the earth appeared in their infancy.
The book ends with a stirring present-tense account of what happened during the northern-California earthquake of 1989 (generally tied to San Francisco, it did greater damage nearer to its epicenter a couple hours south). Freeways collapsed on top of eachother, bridges swayed and lurched (the upper portion of the Bay Bridge smashed through the lower), skyscrapers jumped, bicyclists were thrown somersaulting through the air… it’s amazing only eighty-ish people died amidst such awesome destruction. The lesson here is that despite human and geologic time existing on such vastly different scales, they are still one and the same, occurring simultaneously.
Crossing the Craton
The last volume of this mammoth is much shorter and written considerably later than the others. It could only exist later because it relies on recent (for 1999) technologies that allow geologists much greater insight into the interior of the US — from Nebraska though Illinois (A.K.A. The Craton). For much of the history of science, the stable center of North America was considered to have been there, unchanged, since the fiery creation of the earth. Recent finds show that the craton came together like everywhere else: plates grinding and slamming into eachother with land aboard, little archipelagos and islands getting crunched together to form larger masses, ocean floor sliding under other ocean floor to melt and push up mountains. There’s mountains buried in Kansas, far below any human capacity to drill. Gravity surveys and isotopic dating allow us to see below.
This path pushes geology beyond the realm of rocks into astronomy and biology. It allows us to envision a world before plant life. It causes us to face the stunning truth that plenty of our modern rocks are reinforced or made of the fossilized shells of ancient vertebrates. It also gives us a vision of the early earth — extremely hot and withstanding the constant pummeling of meteors. Those same rocks are still there… somewhere. The oldest rocks any humans have discovered are around 4 billion years old, approaching the age of the earth.
This book was very long. I mostly enjoyed it. I worried throughout that I was not retaining enough. Indeed, a great fraction of this text passed through my brain and skiied beyond into the great blue yonder. Yet while camping this Memorial Day weekend, in northern California beside a river cutting into a mountain valley, leaping from water-eroded rocks that looked like ancient volcanic debris, laying down a towel upon pulverized rock and tracing the track of the river, I felt a geologic sense, an interest and understanding I owe to reading Annals of the Former World. It was only while writing this paragraph that I thought to look and confirm that the river I was staying on — The Eel river — was created by the San Andreas fault, which I was reading about while lounging on its shores.