1. In this weeks lessons we will be investigating what is the nature of weathering and mass movement? By the end of today’s lesson you will be able to describe and explain: Chemical weathering The process of soil creep.

2. Chemical weathering is the decomposition of rock caused by a chemical change within the rock. Rainwater is slightly acidic. Rainwater reacts with rocks particularly with limestone, it causes the rock to rot and crumble away. Water and heat make chemical weathering happen faster so It’s affects are greatest in warm, moist climates.

4. 1.Can you explain the term ‘mass movement’ use the glossary? Mass movement is the downhill movement of weathered material under the action of gravity. This movement transports rocks and soil.

5. Soil creep is the slowest process of mass movement. It occurs in moist climates on low angled vegetated slopes with a soil layer. The low angle of slope and vegetation cover encourage the rainwater to seep into the soil providing lubrication for downhill movement. But the low slope angle and the binding effect of the vegetation roots make this downhill movement a very slow process, typically less than 1cm a year. Terracettes, or small wrinkles on a grassy slope, are produced by this process.

9. Complete worksheets 13.4/13.5 for next. lesson