| A | B |
|---|
| bedrock | the bottom layer of soil, made mostly of solid rock |
| igneous rock | rock formed when melted rock hardens |
| lava | magma that is exposed at Earth’s surface |
| magma | melted rock within Earth |
| metamorphic rock | rock made from igneous or sedimentary rock that has been changed by pressure, heat, very hot water, or a combination of these factors |
| metamorphism | the process by which metamorphic rock is formed |
| mineral | a natural, solid substance that has a definite chemical composition and physical structure |
| rock cycle | all of the processes that change rock from one type to another |
| sedimentary rock | rock formed when layers of sediment settle and are cemented together |
| topsoil | the top layer of soil, made in part from broke-up pieces of lower layer of rock |
