Contents
Plate Tectonics
- Evidence
- Mechanism
- Ancient Earth
Overview
Plate tectonics is the scientific theory that the surface of the Earth is divided into about 15 plates that move relative to one another and interact at their boundaries. It is the unifying idea of geology because it explains so many geological features of the Earth. For example, plate tectonics tells us why earthquakes occur in some places, but not others. It also explains the distributions of features like mountains and volcanoes on Earth's surface.
This chapter will introduce the evidence that convinced geologists that the positions of the continents have changed over time, as well as the discovery of the mechanism that drives this movement. Then, we will explore the different ways in which the continents interact at their margins, and the consequences of those interactions. This chapter will conclude with an overview of how understanding modern plate tectonics allows us to reconstruct what Earth was like at points in time millions of years in the past.