Earth Then Now Author:Carla W. Montgomery This edition has been updated and revised to incorporate equal coverage of both physical and historical geology. It features: expanded discussion of dinosaurs in a chapter entitled "Mesozoic Life"; a new chapter, "The Proterozoic", which contains a thorough discussion of the origin of life; revised discussion of the solar system has been combine... more »d with "The Archean" to provide fundamental background information on the origin of the planet; and coverage of volcanic activity, earthquakes, coastal erosion and hazards, flooding, water supply, and landslides and human activities.« less