soil and weathering

3. the makeup of rock or soil describing the minerals or elements present in it
5. breakdown or decomposition of rock that takes place when minerals change through chemical processes
6. a soil layer with physical and chemical properties that differ from those of the soil layers above or below it
8. the ability to let water pass through
10. the top layer of soil that contains humus
12. the process of wearing something down by friction
14. the size, shape, and position of the particles of soil
16. the amount of open space between an object
17. the process by which natural forces break down rocks and soil

1. the process by which rainwater dissolves and carries away minerals and nutrients in topsoil
2. the expansion of desert conditions in an area where the natural plant cover has been destroyed
4. the breakdown of rock into smaller pieces of the same material without any change to its composition
7. a chemical reaction in which an element and oxygen combine
9. the process in which layers or sheets of rock gradually break off
11. the decaying organic matter in soil
13. layer of rock beneath the soil
15. the process in which transported sediment is laid down