Soil and Weathering

8. the process by which rainwater dissolves and carries away minerals and nutrients in topsoil
10. layer of rock beneath the soil
12. horizon a soil layer with physical and chemical properties that differ from those of the soil layers above or below it
13. the expansion of desert conditions in an area where the natural plant cover has been destroyed
14. the process in which sediment is picked up and moved from one place to another
15. a chemical reaction in which an element combines with oxygen to form an oxide; iron oxide = rust
16. the amount of open space between an object
18. the decaying organic matter in soil

1. weathering breakdown or decomposition of rock that takes place when minerals change through chemical processes
2. the process in which layers or sheets of rock gradually break off
3. the top layer of soil that contains humus
4. the makeup of rock or soil describing the minerals or elements present in it
5. the process by which natural forces break down rocks and soil
6. the ability to let water pass through
7. weathering the breakdown of rock into smaller pieces of the same material without any change to its composition
9. the process of wearing something down by friction
11. the process in which transported sediment is laid down
17. the size, shape, and position of the particles of soil