With his usual flair McPhee embodies the driving spirit of geology's language--"crunching scum," "orogeny," "kettles," "kames"--in a running biography of Anita Harris, a plain-talking, practical-minded geologist who learned her earth science at Brooklyn College. Together the two head westward along Interstate 80, with stops at the Delaware Water Gap, Pennsylvania coal and oil towns, then on to Ohio and Indiana. There is a nostalgic trip home too, a poignant remembrance of Williamsburg slums and a Coney Island girlhood. The result is a kind of journey within a journey, a personal narrative and a chance for Harris to speak long authoritative passages on the outcrops and morains, to pour hydrochloric acid on limestone, and in general to play geology lecturer to McPhee's invisible questions. Don't expect to come away with a working knowledge of geology, however. The lingo is thick and McPhee leaves a lot unexplained. Instead you get a sense of geological time condensed and encapsulated. As Harris says, "The goal of many geologists is to make time-lapse maps of earth history." You also get opinions. Harris is an outspoken critic of the "plate tectonic boys" for going too far. "It's a lazy man's out," she says, faulting the new breed of geologists for not getting out and getting the data. Rather, they make up stories of "exotic terrains" or occasionally "suspect terrains," clashing and colliding to give rise to the eastern American coastline, for example. Harris has a personal reason to rue the theorists because she hastily jumped on the bandwagon in an early paper that misinterpreted some paleontological findings; now she accepts the basic facts of seafloor spreading and ocean movements, but gets increasingly uneasy as plate tectonics is applied to inland areas. "But we can't altogether complain. Plate tectonics has turned people on. It has brought a lot of new people into geology." With Basin and Range (1981) and this latest excursion, McPhee has done the same thing, stylishly, for the general reader.