Earth is made up of different layers: crust, mantle, and core. The crust is solid, the mantle is solid on the top and soft below, the core is soft metal on the outside and solid metal in the middle. The crust and solid upper mantle are broken up into huge pieces called plates that float on the soft magma of the lower mantle. The plates are carried along by magma as it moves. The movement of one plate over another can cause mountains to form, as well as creating earthquakes and volcanoes. The movement of plates that slide in opposite directions can cause earthquakes. Plates moving away from each other have magma move up between them, causing new crust to be formed as the magma cools and also causing volcanoes and earthquakes. Scientists map the edges of plates by looking for places where mountains, earthquakes, and volcanoes occur. Pronunciation guide. 24 pages filled with engaging, colorful illustrations and diagrams. Reading Level 1-3, Interest Level 2-5.