McPhee (Irons in the Fire, 1997, etc.) winds up his artful geohistory of the US by going deep into the heartland--Kansas, Nebraska--in pursuit of deep time: the Precambrian. Included in this collection are his four previous forays into geology--Basin and Range (1981, which, to encapsulate, delineated plate tectonics), In Suspect Terrain (1983, Appalachian geohistory and some broadsides at plate tectonic theory), Rising from the Plains (1986, Wyoming curiosities and environmental conundrums), and Assembling California (1993, a showcase for active tectonics). Here he adds "Crossing the Craton"--craton being the rock basement of the continent--delving into the realms of "isotopic and chemical signatures, cosmological data, and conjecture," in the company of geochronologist Randy Van Schmus. McPhee has a way of making deep structures seem freestanding, right there to ogle: "the walls of the rift are three thousand feet sheer," they're also 600 feet below the surface. Dexterous as ever, McPhee takes on the creation--early island arcs and vulcanism and microcontinents--and tells it with all the power and simplicity a genesis story deserves.