Weathering is the breakdown of rocks through physical, chemical, and biological processes. Erosion is the wearing away and transportation of weathered rock and soil and requires movement of earth materials from one place to another. Glacial erosion occurs primarily through two processes: plucking, where frozen rocks are dislodged from the valley floor as the glacier moves overhead, and abrasion, where debris carried on the bottom of the glacier grinds into the landscape. Common landforms of glacial erosion include corries, arêtes, and U-shaped valleys.

1. What is weathering and erosion?
Learning Objectives;
1. To understand processes of weathering
and erosion in glaciated
landscapes.
2. To understand how landforms of
erosion are created.

2. What is weathering and erosion?
• Weathering – the break-
down of rocks (by physical,
chemical and biological
action).
• Erosion – the wearing away
of rocks by the wind, rivers,
sea and ice.
• The difference between the
two is that erosion involves
movement

3. Freeze Thaw Weathering
On your worksheet – complete the following
notes….
Freeze thaw weathering

6. • Debris from
freeze thaw
weathering
• People – for
scale!

7. • Erosion is the break down and wearing
away of rocks involving movement. Ice
erodes by 2 main processes – plucking
and abrasion.
Glacial Erosion

8. 1) Plucking
• Plucking is when rocks and stones
become frozen to the base of the
glacier and are ‘plucked’ from the
ground as the glacier moves down the
valley.

10. 2) Abrasion
• Abrasion occurs when rocks and stones,
picked up by the glacier, through
plucking at the bottom of the glacier,
are rubbed along the bottom of the
valley, digging it out.

11. Abrasion that has been
carried out over rocks in
Iceland – smoothing the rocks

13. Mars Bar time!
• Get out your mars bar and listen to
my instructions to understand why a
mars bar is like a glacier!

14. Landforms of glacial erosionLandforms of glacial erosion
1. Corrie (or Cirque)
2. Arêtes
3. U-shaped valley
4. Pyramidal Peak
5. Hanging Valley

15. How does the landscape change after a glacial period?How does the landscape change after a glacial period?

16. Video of glaciated erosional
features

17. The Main Event
• You have a pack on your desks – in this pack you
have.
1. Diagram of a glaciated area
2. Five explanation cards of how the landforms of
erosion were created
• In pairs can you identify the 6 key features from
the information provided. Write the correct
names next to the numbers.
• You only need to use numbers 1,2,3,4,9 & 10 (one
feature appears twice
• Then annotate the diagram to explain how they
formed

19. Corries
What happens
when two
corries erode
back towards
each other?

20. Corrie – contour patternCorrie – contour pattern
Corrie
contours
close
together
= ???

21. Arete
corrie

22. 3) U shaped valley3) U shaped valley

25. Your turn!

26. Homework
Complete the worksheet on a recent
fieldtrip to a glaciated area

27. Gimme 5
• Think of one thing new that you have
learnt today and I will ask 5 people to
tell me what they have learnt in this
lesson!