2. Many things cause this to happen. There are two types of weathering: Mechanical (physical) Chemical

3. It is when rocks break down into smaller pieces because of some physical force. The rock does not change chemically, it just gets smaller!

4. Photo by A. Criminger Freezing and thawing is breaking these rocks apart!

5. Photo by A. Criminger Roots are breaking these rocks apart.

6. Photo by A. Criminger Ice is breaking these rocks apart

7. Chemical weathering occurs when rocks are broken down by a chemical reaction. This can happen by water, oxygen, acid rain, and even living things.

8. Photo by A. Criminger This rock is being broken down by the chemicals in the roots of the lichen growing on the rock.

9. Photo by A. Criminger Sometimes rocks are not the only things that get chemically weathered!

10. Erosion now takes place. Erosion is the moving of sediment (broken rocks and plant material) to a new location.

11. http://www.geography.wisc.edu/department/overview.htm What is the evidence that sediment is being moved from one place to another?

12. Copyright © Marli Miller, University of OregonUniversity of Oregon http://www.csiro.au/files/mediaRelease/mr2000/dust.htm www.wilderness.org.au Wind moved the sand into a dune.

13. A glacier is a “river” of ice that slowly moves downhill. As it travels, it breaks off rock and carries it to a new location – EROSION! Copyright © Marli Miller, University of OregonUniversity of Oregon Rocks moved by a glacier. This is glacier deposition. What does the word “deposit” mean? Copyright © Bruce Molnia, Terra Photographics

14. Courtesy National Oceanic and Atmospheric AdministrationNational Oceanic and Atmospheric Administration Glaciers form U shaped valleys. Copyright © Larry Fellows

15. Copyright © Marli Miller, University of OregonUniversity of Oregon Notice the sediment deposited by the river and the wind.

17. Much of the life on earth depends on soil. Soil is made of weathered rock and decayed parts of plants and animals. Soil provides the nutrients needed by most plants to grow. http://tiee.ecoed.net Photo: A. Criminger

18. The first step is for bedrock to be broken down by weathering. This weathering can happen by wind, water, or changes in temperature. WindWaterTemperature Copyright © Bruce Molnia, Terra Photographics Copyright © Marli Miller, University of OregonUniversity of Oregon Photo: A Criminger

19. Organisms such as bacteria and fungi begin to grow in the broken down bedrock. http://waterandlife.org/MicroBiota.htm Soil bacteria (Image: USDA) Soil fungi These organisms live and die providing the soil with nutrients that other plants need to grow.

20. 1. Rock particles 2. Minerals 3. Decayed plant and animal material 4. Air 5. Water

21. This is called a soil profile! http://epod.usra.edu

22. North Georgia soil profile http://www.ga.nrcs.usda.gov/technical/soils/red.html Not all Georgia soils are red, but many of them are. The State is well known for its abundance of "Georgia Red Clay". People often ask why the soils are red. The red color that is so evident in Georgia soils is due primarily to iron oxides. Georgia soil is red because the iron in it has bonded with oxygen forming molecules of “rust.”

23. Without soil, life on earth would be very different.  Imagine no plants that grew in soil.  No animals that grazed on plants.  Where would we get our food?  What would we eat?  What do you think?