| A | B |
|---|
| weathering | Process that breaks down rocks and other substances at the earth's surface |
| erosion | movement of rock particles by wind |
| mechanical weathering | physically breaks rock into smaller pieces |
| chemical weathering | breaks down rock through chemical changes |
| ice wedging | ice in cracks of rock expand and widen and deepen cracks |
| abrasion | grinding away of rock by rock particles carried by wind |
| permeable | material has small connected air spaces allowing fluids to flow through it |
| soil | loose weathered material on earths surface |
| bedrock | layer of soild rock beneath the Earths surface |
| humus | dark colored remains of dead organisms |
| loam | soil made up of equal parts of sand |
| soil horizon | layer of soil that differs in color and texture from that above and below it |
| topsoil | Horizon A made of crumbly dark mixture of humus |
| litter | loose layer of dead plant materials not yet decayed |
| subsoil | Horizon B consisting of clay and other materials washed down from topsoil |
| decomposers | microbes in soil that break down the remains of dead organisms |
| regolith | Horizon C consisting of partially weathered bedrock |
