| A | B |
|---|
| weathering | the slow breaking apart of rock into smaller pieces |
| erosion | movement of weathered rock material from one place to another |
| soil | loose material that covers much of Earth |
| humus | remains of dead plants and animals |
| topsoil | most fertile, uppermost layer of soil |
| subsoil | beneath the topsoil, has some pieces of rock |
| bedrock | beneath the subsoil |
| igneous | formed from molten rock cooling |
| sedimentary | has layers from piling up over time |
| metamorphic | formed from extreme heat and pressure |
