| A | B |
|---|
| weathering | The breakdown of rock into smaller and smaller pieces by mechanical or chemical means. |
| mechanical weathering | The breakdown of rock into smaller pieces by physical means. |
| chemical weathering | The chemical breakdown of rocks and minerals into new substances. |
| acid precipitation | Precipitation that contains acids due to air pollution. |
| oxidation | A chemical reaction in which an element combines with oxygen to form an oxide. |
| differential weathering | The process by which softer, less weather-resistant rocks wear away, leaving harder, more weather-resistant rocks behind. |
| soil | A loose mixture of small mineral fragments and organic material. |
| bedrock | The layer of rock beneath the soil. |
| parent rock | Rock that is the source of soil. |
| humus | Very small particles of decayed plant and animal material in soil. |
| topsoil | The top layer of soil that generally contains humus. |
| soil conservation | The various methods by which humans take care of the soil. |
| ice wedging | Water falls into an existing crack in a rock, freezes and expands, widening the crack. |
| lichens | algae and fungi living together, creating organic acids that eat at rock |
| crop rotation | slows the process of nutrient depletion from soil |
| Ex. Rain slowly breaks down granite into sediment | Chemical |
| Ex. A statue is discolored by acid rain | Chemical |
| Ex. A plant root expands an exsting rock crack | Mechanical |
| Ex. Devil's Tower | Differential Weathering |
| Ex. Rust (Iron Oxide) | Chemical |
| Arctic climate | similar to desert climate, dry, but cold too |
| Temperate Climate Soils | Thick and fertile, due to just the right amount of chemical weathering |
| cover crop | planted between harvests to reduce soil erosion and replace nutrients |
