The Scoop on Soil

Of What is Soil Made? sand rocks dried plants dead organisms water air

Soil Stacks Up

What are Some Processes that Form Soil? Decay of plant matter Settling of volcanic ash Transport by rain, streams, and rivers Deposition of sediments in rivers and lakes Weathering Erosion

Decay of Plants

Settling of Volcanic Ash

Transport by Rain

Deposition of Sediment

Weathering

There are Two Main Types of Weathering Mechanical Chemical

In the next 7 slides, try to determine what caused the weathering.

Erosion

Erosion from Gravity

Erosion by Wind

Erosion by Water

Erosion by Ice

What’s good about erosion? New soil is formed. Erosion results in deposits of dark, fertile soil, perfect for growing crops. Erosion reveals marvels of nature such as mountains, sandstone arches, and polished cliffs. Without erosion, rock debris would simply pile up. Soil erosion may slow down global warming by carrying carbon into wetlands where it is stored for long periods of time. (theory)

What’s bad about erosion? Land can be stripped of soils needed for food to grow. Landslides can destroy whatever is in their paths. Rivers can be filled with silt, disrupting their ecosystems. Erosion causes cracks, gaps, and ditches in the landscape. When soil erodes, it cannot support many types of plant life.

What can be done to prevent erosion? Plant trees and bushes along riverbanks to hold soil in place. Plant trees that will block the wind. Use careful, smart farming practices that won’t disturb topsoil. Use common-sense approaches to construction, such as don’t build on steep slopes. When hiking, stay on trails.

Review Answer: Weathering is breaking down rock into pebbles and sand by physical or chemical processes. 1. What is weathering?

2. Give at least three examples of weathering processes. Answer: Wind, water, ice, heating, cooling, acid rain.

3. What is erosion? Answer: Erosion is the movement of Earth materials by processes such as wind, water, ice, and gravity.

4. Explain how the formation of soil is related to weathering of rock. Answer: Rocks are broken into small pieces by the process of weathering. Then the small particles become part of the soil.

5. How does deposition of sediments relate to soil formation? Answer: As sediments fall to the bottom of rivers and lakes, they build up deposits to form soil.

6. Name at least two forces that cause erosion. Answer: Wind, water, gravity.

7. What is soil? Soil is the thin living skin that covers the land. It goes down into the ground just a short way. Soil is more than rock particles. It includes all the living things and the materials they make or change. Soil is a precious resource that sustains life on earth.

8. Name at least three layers of soil. Organic layer, topsoil, subsoil, parent material

9. What can you personally do to help prevent erosion? Plant trees and bushes along riverbanks to hold soil in place. When hiking, stay on trails.

What process causes landslide erosion? gravity

Credits The Rock Cycle Soil Forming Factors Dirt: The Scoop on Soil (Amazing Science) [Paperback] RosinskyRosinsky, Natalie M (Author)Natalie M The Open Door Website Soil Profile Soil is not dirt The Dirt on Soil What is soil? Geography4Kids.com Tree Hugger Deadly Landslides in Guatamala Wikipedia Weathering and Soils Soil Forming Factors How Stuff Works terms/volcanic-ash.htmhttp://science.howstuffworks.com/dictionary/petrology- terms/volcanic-ash.htm North Coast Journal Just the facts