TABLE OF CONTENTS CHAPTER 1 10 18 The Rock Cycle Begins 4 CHAPTER 2 Types of Rock CHAPTER 3 Rock Tells a Story ACTIVITIES TOOLS Try This 22 Glossary Index 24 To Learn More 24 23
CHAPTER 1 THE ROCK CYCLE BEGINS Earth is always changing Old rock breaks down New rock forms It is always being recycled
This change is called the rock cycle Earth began as a ball of hot gases and dust When More than 4 5 billion years ago It cooled The top layer or crust turned to rock
