1. Weathering, Soil, and Mass Movement1

2. What is Weathering?
The breaking down and changing of rocks near Earth’s surface 2

3. Mechanical Weathering?
Physical forces break rock into smaller pieces without changing the rock’s composition. 3

4. Mechanical Weathering and Surface Area

5. Frost Wedging Expansion of freezing water in cracks and crevices
Eventually breaking rocks into pieces
Sections of rock that are wedged loose are called talus 5

6. Unloading
The uplift and erosion of rocks overlying igneous rocks because pressure on rocks is reduce
Exfoliation—slabs of outer rock separate and break loose 6

7. Biological Activity
The activity of plants, burrowing animals, and humans
Plant roots wedge into rocks breaking them apart 7

8. Chemical Weathering?
the transformation of rock into one or more new compounds 8

9. Agents and Evidence of Chemical Weathering
Water: most important agent of weathering. It picks up CO2 and SO2 in the air which forms acid rain. 9

10. Rate of Weathering How fast the rocks erode Two factors
Rock characteristics
Mineral composition and solubility
Climate
Temperature and moisture
Favors high temperature and abundant moisture 10