| A | B |
|---|
| physical weathering | breaking of rocks into smaller pieces |
| mantle | middle layer of earth |
| core | center of earth |
| crust | outside layer of earth |
| chemical weathering | changes the minerals in rocks |
| oxides | material formed when oxygen joins chemically with a mineral |
| erosion | moving of weathered rock and soil |
| runoff | water that drains off land |
| sediment | soil, sand and rocks carried by wind and water |
| deposition | dropping of sediments moved by erosion |
| glacier | large, slow-moving mass of ice |
| ice age | period of many years when snow and ice cover much of the earth |
| rock cycle | ways that rocks change from one form to another |
| igneous rock | formed from cooled magma |
| crystal | substance made of atoms arranged in a repeating pattern |
| sedimentary rock | rock formed from pressed sediments |
| shale | example of sedimentary rock |
| granite | example of igneous rock |
| metamorphic rock | formed when heat and pressure change minerals in other rocks |
| slate | an example of metamorphic rock |
| petrify | replace molecules in dead organisms with minerals |
| mold | a hollow left in sediment aftr an organism dissolves |
| imprint | track of organism preserved in rock |
| cast | fossil formed by sediments filling a mold |
| dune | built-up layers of sand caused by wind |
