Overview:The Land Beneath the Sea

In this unit, students are introduced to the concept that Earth is not solid, and that its crust fl oats on magma. They learn that crust sections (tectonic plates) fl ow over or under, and toward or away from, each other. They also discover that colliding plates at converging boundaries create earthquakes, mountain ranges, valleys, deep trenches, and island chains, while plates at diverging boundaries create rift valleys and oceans.