In ROUGH-HEWN LAND, Keith Heyer Meldahl (a Professor of Geology) takes the reader on a geological journey eastward, starting at the Golden Gate and ending on the eastern edge of the Rocky Mountains. The north-south band of his tour centers roughly on Interstate Highway 80. He explores such things as the pillow basalt heaped up around the Golden Gate (volcanic basalt that once formed part of the ocean floor thousands of miles west of California); other geological aspects of the accreted terranes that form the entire west coast of North America for one hundred or more miles inland; the gold and other mineral resources of the Sierra Nevada foothills; the dramatic evidence of past earthquake activity throughout much of the West and the geological reasons for it; the Basin and Range province, where to a degree unmatched anywhere else the Earth's crust has been stretched like an accordion; and the formation of the Rocky Mountains, where some of the oldest rock of the continent can be found on mountain summits.
What underpins the geology of the book is plate tectonics, and Meldahl helped me appreciate much better that the explanatory power of plate tectonics is roughly on a par with the concept of biological evolution and with quantum physics. Most of the book is in accord with the current consensus of geological science, though on a few specifics Meldahl ventures beyond the accepted consensus. For instance, does the San Andreas fault mark the western edge of the North American Plate, as reflected in all the textbooks? Meldahl says no, that wedged between the Pacific Plate and the North American Plate there is a separate plate that moves on its own, which he calls the "Sierran Plate".
Meldahl interlaces his discussion of geology with incidents from history - for example, the Gold Rush and the Donner Party -- that were heavily influenced by features of Western geology. (Those historical discussions exemplify Robert Penn Warren's remark that "history is all explained by geography, and geography is all explained by geologic forces.") Meldahl's writing is hip and informal, colorful and creative. He has a slightly wacky sense of humor (for instance, he says that about the only benefit to Californians from living along the edge of a tectonic plate is "the thrill of knowing that death from an earthquake could come any day, which naturally makes each latte and yoga lesson more meaningful.")
What makes the book particularly appealing, and comprehensible, are the many excellent schematic illustrations and helpful photographs. Imagine, then, John McPhee's classics on geology (the works assembled in "Annals of the Former World") updated and intelligently illustrated. That is close to what you get with ROUGH-HEWN LAND, albeit without McPhee's stylistic filigree. If anything, ROUGH-HEWN LAND is even more comprehensible to the interested layperson than McPhee.
I admit to a personal fascination with geology. If I could re-run my life, I would seriously consider studying geology, perhaps even making that my profession. But one need not have as strong an interest in geology as I do to appreciate ROUGH-HEWN LAND. Indeed, to enjoy reading the book one probably need not even have had at the outset a distinct interest in geology at all - though by book's end there is a good chance such an interest has been kindled.