| A | B |
| erosion | the process by which water, ice, wind, or gravity moves weathered rock and soil |
| sediment | earth materials deposited by erosion |
| deposition | process in which sediment is laid down in new locations |
| mass movement | one of several processesby which gravity moves sediment downhill |
| runoff | water that flows over the ground surface rather than soaking into the ground |
| rill | a tiny groove in soil made by flowing water |
| gully | a large channel formed in soil by erosion |
| stream | a channel through which water water is continually flowing downhill |
| river | a large stream |
| tributary | a stream that flows into a larger stream |
| drainage basin | the land area from which a river and its tributaries collect their water |
| divide | the ridge of land that seperates one drainage basin from another |
| flood plain | wide valley through which a river flows |
| meander | a looplike bend in the course of a river |
| oxbow lake | a meander cut off rom a river |
| alluvial fan | a wide sloping deposit of sediment formed where a stream leaves a mountain range |
| delta | a landform made of sediment that is deposited where a river flows into an ocean or lake |
| groundwater | water that fills the cracks and spaces in underground soil and rock layers |
| stalactite | a calcite deposit that hangs from the roof of a cave |
| stalagmite | a cone-shaped calcite deposit that builds up from the florr of a cave |
| karst topography | type of landscape in a rainy region, limestone near surface, characterized by caverns, sinkholes, and valleys |