1. < BackNext >PreviewMain Weathering and Soil Formation Section 1 WeatheringWeathering Section 2 Rates of WeatheringRates of Weathering Section 3 From Bedrock to SoilFrom Bedrock to Soil Section 4 Soil ConservationSoil Conservation Chapter 10 Preview Concept Mapping

2. < BackNext >PreviewMain Section 1 Weathering Bellringer Think about how potholes form in paved roads. Write a few sentences that describe how water contributes to the formation of potholes. Illustrate how cycles of freezing and thawing help cause potholes to grow. Record your response in your science journal. Chapter 10

3. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Describe how ice, water, wind, gravity, plants, and animals cause mechanical weathering. Describe how water, acids, and air cause chemical weathering of rocks. Objectives

4. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Mechanical Weathering Ice The alternate freezing and thawing of soil and rock, called frost action, is a form of mechanical weathering. Abrasion Abrasion is the grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles. Wind, Water, and Gravity Wind, water, and gravity carry rocks, causing them to abrade against one another.

5. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Ice Wedging Click below to watch the Visual Concept. Visual Concept

6. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Mechanical Weathering, continued Plants As a plant grows, the force of the expanding root becomes so strong that it can break a rock apart. Animals Almost any animal that burrows causes mechanical weathering by mixing and digging through soil and rock particles.

7. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Animals and Mechanical Weathering Animals that burrow in the ground break up soil and loosen rocks to be exposed to further weathering.

8. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Chemical Weathering Water Even hard rock, such as granite, can be broken down by water. The next slide shows how this can happen. Acid Precipitation The high level of acidity in acid precipitation can cause very rapid weathering of rock. Acids in Groundwater When acidic groundwater comes into contact with limestone, the limestone is dissolved and forms karst features.

9. < BackNext >PreviewMain Section 1 Weathering Chapter 10

10. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Chemical Weathering, continued Acids in Living Things Some living things, such as lichens, produce acids that can slowly break down rocks. Air Oxygen in the air causes oxidation. Oxidation is the chemical reaction in which an element, such as iron, combines with oxygen to form an oxide.

11. < BackNext >PreviewMain Section 1 Weathering Chapter 10 Oxidation Click below to watch the Visual Concept. Visual Concept

12. < BackNext >PreviewMain Section 2 Rates of Weathering Bellringer Imagine that you are in a sand castle-building competition at the beach. Come up with ways to protect your castle against the weathering effects of the wind and waves. Record your response in your science journal. Chapter 10

13. < BackNext >PreviewMain Section 2 Rates of Weathering Chapter 10 Explain how the composition of rock affects the rate of weathering. Describe how a rock’s total surface area affects the rate at which the rock weathers. Describe how differences in elevation and climate affect the rate of weathering. Objectives

14. < BackNext >PreviewMain Section 2 Rates of Weathering Chapter 10 Differential Weathering What Is Differential Weathering? Differential weathering is a process by which softer, less weather resistant rock wear away and leave harder, more weather resistant rock. The image below is an example of differential weathering.

15. < BackNext >PreviewMain Section 2 Rates of Weathering Chapter 10 The Shape of Rocks Surface Area The more surface area of a rock that is exposed to weathering, the faster the rock will be worn down. Increasing the Rate of Weathering If a large rock is broken down into smaller fragments, weathering of the rock happens much more quickly.

16. < BackNext >PreviewMain Section 2 Rates of Weathering Chapter 10

17. < BackNext >PreviewMain Section 2 Rates of Weathering Chapter 10 Weathering and Climate What Is Climate? Climate is the average weather condition in an area over a long period of time. Temperature and Water The rate of chemical weathering happens faster in warm, humid climates. Water also increases the rate of mechanical weathering.

18. < BackNext >PreviewMain Section 2 Rates of Weathering Chapter 10 Weathering and Elevation High Elevations Rocks at higher elevations, as on a mountain, are exposed to more wind, rain, and ice than rocks at lower elevations. Steep Slopes The steepness of mountain slopes increases the effects of mechanical and chemical weathering. Steep slopes cause water and sediments to quickly run down the side of the mountain.

19. < BackNext >PreviewMain Section 3 From Bedrock to Soil Bellringer Answer the following questions: Has there always been soil on Earth? What makes soil valuable to humans? Write your answers in your science journal. Chapter 10

20. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 Describe the source of soil. Explain how the different properties of soil affect plant growth. Describe how various climates affect soil. Objectives

21. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 The Source of Soil What Is Soil? Soil is a loose mixture of small mineral fragments, organic material, water, and air that can support the growth of vegetation. Residual and Transported Soil Soil that remains above its parent rock is called residual soil. Soil that is blown or washed away from its parent rock is called transported soil.

22. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 Residual and Transported Soil Click below to watch the Visual Concept. Visual Concept

23. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 Soil Properties Soil Texture and Soil Structure Soil texture is the soil quality that is based on the proportions of soil particles. Soil structure is the arrangement of soil particles.

24. < BackNext >PreviewMain Chapter 10 Section 3 From Bedrock to Soil

25. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 Soil Properties, continued Soil Fertility A soil’s ability to hold nutrients and to supply nutrients to a plant is described as soil fertility. Soil Horizons Because of the way soil forms, soil often ends up in a series of layers called horizons. Soil pH Soils can be acidic or basic. The pH scale is used to measure how acidic or basic a soil is.

26. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 Leaching Click below to watch the Visual Concept. Visual Concept

27. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 Soil and Climate Tropical Rain Forest Climates The warm soil in tropical rain forest climates allows dead plants and animals to decay easily. This provides rich humus to the soil. Desert Climates The lack of rain in desert climates leads to low rates of chemical and mechanical weathering.

28. < BackNext >PreviewMain Section 3 From Bedrock to Soil Chapter 10 Soil and Climate, continued Temperate Forest and Grassland Climates Temperate forest and grassland climates get enough rain to cause a high level of chemical weathering, but not too much that nutrients are leached out. Arctic Climates In arctic climates, as in desert climates, chemical weathering occurs very slowly. Low temperatures slow the formation of humus.

29. < BackNext >PreviewMain Section 4 Soil Conservation Bellringer Franklin D. Roosevelt once said: “The nation that destroys its soil destroys itself.” What do you think this quote means? Record your response in your science journal. Chapter 10

30. < BackNext >PreviewMain Section 4 Soil Conservation Chapter 10 Describe three important benefits that soil provides. Describe four methods of preventing soil damage and loss. Objectives

31. < BackNext >PreviewMain Section 4 Soil Conservation Chapter 10 The Importance of Soil Nutrients Soil provides minerals and other nutrients for plants. All animals get their energy from plants. Housing Soil provides a place for animals to live. Water Storage Without soil to hold water, plants would not get the moisture or the nutrients they need.

32. < BackNext >PreviewMain Section 4 Soil Conservation Chapter 10 Soil Damage and Loss Overuse Overused soil can lose its nutrients and become infertile. Soil Erosion When soil is left unprotected, it can be exposed to erosion. Erosion is the process by which wind, water, or gravity transport soil and sediment from one location to another.

33. < BackNext >PreviewMain Section 4 Soil Conservation Chapter 10 Contour Plowing and Terracing Contour Plowing In contour plowing, the rows of soil act as a series of dams to prevent water from eroding topsoil away. Terracing If hills are steep, farmers can using terracing. Terracing changes one steep field into a series of smaller, flatter fields.

34. < BackNext >PreviewMain Section 4 Soil Conservation Chapter 10 Cover Crop and Crop Rotation Cover Crops Cover crops are crops that are planted between harvests to replace certain nutrients and prevent erosion. Cover crops prevent erosion by providing cover from wind and rain. Crop Rotation Farmers can rotate crops that use different nutrients so that nutrients in the soil have time to become replenished.

35. < BackNext >PreviewMain Weathering and Soil Formation Concept Mapping Use the terms below to complete the concept map on the next slide. Chapter 10 parent rock chemical weathering mechanical weathering rock ice wedging oxidation soil

36. < BackNext >PreviewMain Weathering and Soil Formation Chapter 10

37. < BackNext >PreviewMain Weathering and Soil Formation Chapter 10