1. Weathering

2. Lesson Aims ALL – to know what weathering is
MOST – to know what mechanical, chemical and biological weathering is
SOME – to know different ways that mechanical, chemical and biological weathering occurs

3. Today’s key terms: Weathering Mechanical weathering
Chemical weathering
Biological weathering
Freeze-thaw weathering
Exfoliation
Solution
Scree
Pores

4. Watch the slide show
Watch the slide show of images and information to do with weathering.
Take notes in your books
It does not have to be full sentences it can bullet points

5. Weathering is the break down of rocks in their original place (the rocks do not move they get worn away from where the are)

6. It is largely caused by elements of the weather such as rainfall and changes in temperature

7. Mechanical weathering is also known as physical weathering

8. Mechanical weathering breaks up rocks without any chemical changes
Mechanical weathering breaks up rocks without any chemical changes. It often results in piles of angular rocks called scree at the base of the rock feature.

9. Chemical weathering is a chemical reaction between the rock and acidic rainwater

10. Biological weathering involves the actions of flora and fauna
Biological weathering involves the actions of flora and fauna. Plant roots are effective at growing and expanding in cracks in rocks

11. Mechanical weathering – Freeze Thaw
Wider world page 234
Take notes on what freeze-thaw weathering is
Then copy this diagram

12. Mechanical weathering – Exfoliation
Wider world page 234
Take notes on what exfoliation is

13. Chemical weathering – Solution
Wider world page 234
Take notes on what chemical weathering is
Then copy this diagram

14. Quiz
Weathering is the breakdown of rocks where they are carried away. True or False?
What type of weathering is freeze-thaw?
Name a type of chemical weathering
What type of weathering involves plants breaking down rocks?
What is the name for angular rocks?
What is mechanical weathering also known as?
Chemical weathering is a reaction between the rock and what else?
Chemical weathering reacts strongly with which two rocks?

15. Answers False Mechanical Solution Biological Scree Physical weathering
Acidic rainwater
Limestone and chalk

16. Homework
Choose one rock type to research – metamorphic, igneous, sedimentary
Create an A3 poster on your rock type. Include the following:
Position on geological timescale
How it was created linking with the rock cycle
Features of the rock type
Examples of rock
Images / diagrams
Example of a place in the UK with that rock type
How it might be affected by weathering
How that rock type may be used for example in concrete of for building

17. Lesson Aims ALL – to know what weathering is
MOST – to know what mechanical, chemical and biological weathering is
SOME – to know different ways that mechanical, chemical and biological weathering occurs