Part travelogue, part history of geological thought, part geology explanation. I wonder if he was trying to appeal to the non-geologist and demonstrate how the landscape forms a part of the work of the geologist. I think he was successful, but I often found the florid landscape descriptions distracting. I also didn't learn much that I hadn't learned already on the Discovery Channel, except for the detailed descriptions of different rocks and formations.
And yet, somehow I felt by the end of the book that I had a different, maybe more comprehensive, maybe more intimate, portrait of the earth and the study of that fascinating, very complex body.