1 / 25

Soil Recap

Soil Recap. What did you learn by digging through your soil and observing the soil of others ?. What is soil?. Loose, weathered material on Earth’s surface. Made up of: -rock particles -minerals -decayed organic material (humus) (HYOO mus ) -water -air.

langer
Download Presentation

Soil Recap

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Soil Recap

  2. What did you learn by digging through your soil and observing the soil of others?

  3. What is soil? • Loose, weathered material on Earth’s surface. • Made up of: -rock particles -minerals -decayed organic material (humus) (HYOO mus) -water -air

  4. What does soil texture depend on? • Particle size! Which particle type Is the best for plant Growth? Loam- Soil that is equal parts clay, sand, and silt

  5. What are soil horizons and how are they formed? Horizon: • A layer of soil that differs in color and texture from the layers above or below it • Topsoil, subsoil and bedrock • Check out this animation of how horizons form: Pearson Prentice Hall: Web Codes • How do living organisms help the soil’s fertility? • Decomposition-page 52

  6. How do scientists classify different types of soil? • They are classified based on climate, plants and soil composition • Look at page 51-Which soil type exists where we live? What climate and vegetation types occur in our region?

  7. Why is soil one of Earth’s most valuable natural resources? Everything that lives on land, including humans, depends directly or indirectly on soil. • What can be done to preserve soil? • Contour plowing • Conservation plowing • Crop rotation

  8. How does weathering occur? What is the difference between weathering and erosion?

  9. Weathering vs. Erosion • Weathering and erosion work together… • You can’t see weathering – wearing down over rock over time • Erosion is a movement of dirt/soil particles by wind, water, ice or gravity

  10. Weatheringis the process by which rock materials are broken down by the action of physical or chemical processes. • Mechanical weathering is the breakdown of rock into smaller pieces by physical means • Chemical weathering is the process by which rocks break down as a result of chemical reactions. Water, weak acids, and air can cause chemical weathering.

  11. Causes of Mechanical Weathering Ice Wedging Water seeps into cracks during warm weather. When temperature drops, the water freezes and expands, causing the ice to push against the sides of the crack. This causes the crack in the rock to widen. Abrasion The grinding and wearing away of rock surfaces through mechanical action of other rock or sand pebbles. • Wind and water are forces of abrasion

  12. John Ford Point Monument Also See Fig. 13.7 of the Colorado Plateau Figure 3.8: Ship Rock Arizona Volcanic Neck Fig 5.3 John Ford Point Monument, Arizona. Ship Rock, New Mexico Volcanic Neck

  13. Chemical Weathering • is the process by which rocks break down as a result of chemical reactions. • New mineral composition!

  14. Causes of Chemical Weathering Water Oxygen CO2 Living Organisms Acid Rain

  15. H2O Dissolves minerals in rock

  16. Acid Rain CO2 Forms carbonic acid, dissolves limestone

  17. Oxidation

  18. Types of Mechanical Weathering LIVING ORGANISMS

  19. Factors that affectRates of Weathering • Joints, fractures and/or porosity increase surface area • This can accelerate both mechanical and chemical weathering

  20. More factors that affectRates of Weathering • Type of Rock • Hard rocks weather more slowly than softer rocks • Limestone vs. granite and permeability • Climate • Chemical weathering occurs faster in warm, humid climates

  21. Exit slip • Give examples of weathering and erosion in nature

More Related