Unit Review

4. This layer of soil contains clay, minerals, and organic matter. Often found in older soils.
6. What is the outside layer of the Earth called?
7. Fossils help scientists understand how what were formed?
9. There are how many steps in the process of forming a fossil?
10. This type of soil feels sticky and plants do not grow well in it.
11. Bones, teeth, shells, plants, and footprints are remains that can turn into what?
13. What helps plants grow strong?
14. A mass of rock such as granite, basalt, quartzite, limestone, or sandstone.
16. This layer of soil is mostly made from organic matter such as decomposing leaves
18. Being strong and durable makes them perfect for building.
19. Quartz and Copper are examples of a very useful substance found in the Earth.
20. This layer of soil is full of minerals for plants and other organisms to live.

1. Which layer is the Earth's magnetic field created by?
2. Igneous rocks are formed when this substance cools.
3. The deposit at Earth's surface from which the soil developed
5. Sediments press down and the cause rock to what?
8. Fossils are like these because they help scientists learn about the past.
12. This layer of soil is rich in minerals that have moved down and accumulated here.
15. Water, Wind, and Plants can cause this to happen to soil.
17. This type of soil feels gritty and drains water quickly.