1. Chapter 2: Plate Tectonics I Lesson 1: Earth ’ s Moving Plates CRO #1

2. Ch.2, lesson 1, CRO #1 Describe the makeup and behavior of “ tectonic plates ”. Describe how the tectonic plates are different from the continents.

3. The Tectonic Plates Plates consist of pieces of Earth ’ s lithosphere, the solid, rigid rock in the crust and upper mantle.

4. Meet the plates The lithosphere is divided up into about 15 tectonic plates. Plates have different names and different sizes. Plates interlock like pieces of a jig-saw puzzle but they are able to move relative to each other. See the map on the next slide.

5. Tectonic Plates

6. Things to notice.. All of the plates include some amount of ocean crust. The plate boundaries do not always align with coastlines, many are in the oceans. Many landmasses are carried by more than one plate (including North America). Many plates carry more than one continent (or parts of multiple continents).

7. Plate movement Plates may move with different speeds and in different directions (the speeds range from 11 cm/year to almost 0 cm/yr). They are able to move by sliding over the plastic layer of the mantle called the aesthenosphere. They move by deforming each other and/or one running over top of the other. Where they pull apart, new ocean crust forms.