| A | B |
|---|
| Weathering | The chemical and physical processes that break down rock at Earth's surface |
| Erosion | The process by which water, ice, wind or gravity moves weathered rock and soil |
| Mechanical Weathering | The type of weathering in which rock is physically broken into smaller pieces |
| Abrasion | The grinding away of rock by other rock particles carried in water, ice or wind |
| Ice Wedging | Process that splits rock when water seeps into cracks, then freezes and expands |
| Chemical Weathering | The process the breaks down rock through chemical changes |
| Permeable | Characteristic of a material that is full of tiny, connected air spaces that water can seep through |
| Soil | The loose, weathered material on Earth's surface in which plants can grow |
| Bedrock | The soil layer of rock beneath the soil |
| Humus | Dark colored organic material in soil |
| Soil Horizon | A layer of soil that differs in color and textrue from the layers above or below it |
| Topsoil | Mixture of humus, clay and other minerals that forms the crumbly, topmost layer of soil |
| Subsoil | The layer of soil beneath the topsoil that contain mostly clay and other minerals |
| Litter | The loose layer of dead plant leaves and stems on the surface of the soil |
| Decomposers | Soil organisms that breaks down the remains of organisms and digest them |
