1. Chapter 14:
Weathering

2. Section 2:
Rates of Weathering

3. Differential Weathering
Softer rocks weather faster, based on chemical composition
Hard rock – ie, Quartz resistant
Devil’s Tower – weathering & erosion of cone
Shows joints – areas of weakness

4. Rock Composition Chemical composition & how they are cemented together
Limestone weathers faster than conglomerates & sandstone

5. Amount of Exposure Surface area – smaller rocks weather faster
Fractures & joints – natural points of weakness, allows easy breaking

6. Climate Hot & cold weather fast Warm & humid weather fast
Slowest rate – hot, dry

7. Topography & Elevation
Ice wedging & gravity more common in high elevation – its colder
Water carries rock, exposing more rock
Gravity pulls rock down from steep slopes
Alps with mountain glacier

8. Human Activities and Plant & Animal Activities
Mining, Construction & Recreation
Plants break apart rock
Burrowing
Bats
Guano – chemical
Insects - mechanical

9. End of Section 2 Review
1. Explain how rock composition affect the rate or weathering 2. How does the surface area of a rock affect the rate of weathering 3. Identify two ways that climate can affect the rate of weathering 4. Describe two ways that the topography of a region can affect the rate of weathering 5. Summarize 3 ways that human actions can affect t he rate of weathering 6. Explain two ways that animas can affect the rate of weathering 7. Imagine that there is an area of land where mechanical weathering has cause damage. Describe 2 ways to reduce the rate of mechanical weathering