Soil and weathering

3. the process in which transported sediment is laid down
4. the decaying organic matter in soil
7. the process by which natural forces break down rocks and soil
8. the process in which layers or sheets of rock gradually break off
11. the ability to let water pass through
13. a chemical reaction in which an element combines with oxygen to form an oxide; iron oxide = rust
14. the process in which sediment is picked up and moved from one place to another
15. weathering the breakdown of rock into smaller pieces of the same material without any change to its composition
17. horizon a soil layer with physical and chemical properties that differ from those of the soil layers above or below it

1. the top layer of soil that contains humus
2. the process by which rainwater dissolves and carries away minerals and nutrients in topsoil
3. the expansion of desert conditions in an area where the natural plant cover has been destroyed
5. the amount of open space between an object
6. layer of rock beneath the soil
9. weathering breakdown or decomposition of rock that takes place when minerals change through chemical processes
10. the size, shape, and position of the particles of soil
12. the makeup of rock or soil describing the minerals or elements present in it
16. the process of wearing something down by friction