In this chapter, you will be introduced to some of the most important features of our planet. You will learn about the unique, layered structure of the Earth and about one of the most important theories – the theory of plate tectonics. Everything you learn in this chapter provides the basis for Chapters 2–6 in this book. A good understanding of this chapter will be of great benefit as you progress through the rest of the physical section.
KEY WORDS
l Inner core l Outer core l Mantle l Asthenosphere l Lithosphere l Continental crust l Oceanic crust l Molten
l Plates l Convection currents l Continental drift l Continental fit l Matching fossils l Glacial deposits l Matching mountain ranges l Mid-ocean ridges
l Seafloor spreading l Magma l Lava l Basalt l Ocean sediments l Subduction
LEARNING OUTCOMES
What you MUST know l Each layer of the Earth and their functions l The difference between continental and oceanic crusts l The major crustal plates of the Earth and how they form boundaries l The difference between magma and lava l How convection currents move plates l The theory of continental drift and its proofs l The theory of seafloor spreading and its proofs l The formation of mid-ocean ridges
What you SHOULD know l A number of minor plates, such as the Cocos Plate l Slab pull
What is USEFUL to know l Who discovered the theories of contintental drift and seafloor spreading
