Page 93 - Science Course 2 (Book 2)

The Plate Tectonics Theory Mo10-L3a: What is the Plate Tectonics

Lesson 3 Theory?

Let’s Begin

In this topic, you will learn the following
lessons:
Mo.10–L3a: What is the Plate Tectonics Plate Tectonics
Theory?
The theory of plate tectonics states that Earth’s sur-
Mo.10–L3b: Why Tectonic Plates Move? face is broken into large, rigid pieces that move with
respect to each other.

These pieces, or tectonic plates, move slowly over
What is the Plate Tectonics
Mo10-L3a Theory? Earth’s surface.

KEY CONCEPTS:
1. What is the theory of plate tectonics?

Vocabulary A-Z
Let us learn some vocabulary

plate tectonics
theory that Earth’s surface is broken into large, rigid
pieces that move with respect to each other.

Tectonic plate motion and other processes have
affected North America. The western United States
has tall mountains, while the central region is f at.

lithosphere
the rigid outermost layer of Earth that includes the
uppermost mantle and crust.

asthenosphere
the partially melted portion of the mantel below the
lithosphere. Key Concept
What is the Plate Tectonics Theory?

What is the theory of plate tectonics?

lithosphere
asthenosphere

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