1. Weathering 5.1

2. Mechanical Weathering The physical disintegration of rock , resulting in smaller fragments.

3. Frost wedging The mechanical breakup of rock caused by the expansion

4. Talus An accumulation of rock debris at the base of a cliff.

5. Exfoliation Type of weathering cause by reducing pressure on a rock surface, allowing slabs of outer rock to break off in layers.

6. Chemical Weathering The processes by which the internal structure of a mineral is the altered by the removal and/ or addition of elements.

7. Key Concepts What is the mechanical weathering? Mechanical weathering occurs when physical forces break rock into smaller and smaller pieces without changing the rock’s mineral composition. What is chemical weathering? Chemical weathering is the transformation of rock into one or more new compounds What factors affect the rate of weathering? In nature, three physical processes are especially important causes of mechanical weathering: frost wedging, unloading, and biological activity.