Four main themes are emphasized in this text: plate tectonics; human interaction with our environment; our protection from natural disasters; and our needs and

Movement of the earth's crust -- Earthquakes and volcanoes -- Plate tectonics -- Rocks and minerals -- Weathering and soil formation -- Erosion and deposition.

In the early 1960s, the emergence of the theory of plate tectonics started a revolution in the earth sciences. Since then, scientists have verified and refined