| A | B |
|---|
| abrasion | the grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles |
| alluvial fan | a fan-shaped mass of material deposited by a stream when the slope of the land decreases sharply |
| aquifer | a body of rock or sediment that stores groundwater and allows the flow of groundwater |
| artesian spring | a spring whose water flows from a crack in the cap rock over the aquifer |
| bedrock | the layer of rock beneath soil |
| chemical weathering | the process by which rocks break down as a result of chemical reactions |
| delta | a fan-shaped mass of material deposited at the mouth of a stream |
| deposition | the process in which material is laid down |
| divide | the boundary between drainage areas that have streams that flow in opposite directions |
| floodplain | an area along a river that forms from sediments deposited when the river overflows its banks |
| humus | dark, organic material formed in soil from the decayed remains of plants and animals |
| karst topography | a type of landscape in rainy regions where there is limestone near the surface, characterized by caverns, sinkholes, and valleys |
| leaching | the removal of substances that can be dissolved from rock, ore, or layers of soil due to the passing of water |
| mechanical weathering | the breakdown of rock into smaller pieces by physical means |
| permeability | the ability of a rock or sediment to let fluids pass through its open spaces, or pores |
| porosity | the percentage of the total volume of a rock or sediment that consits of open spaces |
| soil | a loose mixture of rock fragments, organic material, water, and air that can support the growth of vegetation |
| tributary | a stream that flows into a lake or larger stream |
| watershed | the area of land that is drained by a water system |
| water table | the upper surface of underground water; the upper boundary of the zone of saturation |
| weathering | the process by which rock materials are broken down by the action of physical or chemical processes |
