Weathering

3. process in which layers of rock gradually break off as pressure is released from the rock
4. the process by which natural forces break down rocks
6. expansion of desert conditions in areas where natural plant cover has been removed due to human activities
8. the downhill movement of rock and soil
9. very slow movement of soil or debris
10. process of wearing down rock by friction - usually due to water or wind
12. breakdown of rock by chemical reactions that change the rock chemical composition
13. breaking apart of rocks by plant roots growing into rock cracks
15. Low energy, smaller sediment
16. weak acid produced by decaying plants that can chemically weather rocks
18. a basin that forms when the roof of a cave becomes so thin that it suddenly falls in
19. High energy, larger sediment
20. combination of the oxygen in air and water with iron in rocks to produce iron oxide (rust)

1. when weathered particles are picked up and moved from one place to another
2. breaking up of rock by physical force
5. all natural and human-made features of a particular area
7. the slide of loose debris that moves as a single unit
11. rain that contains sulfuric acid from pollution and can cause weathering of rocks
14. when sediment is put down in a new location
17. the repeated freezing and thawing of water in rocks that causes the rock to split apart