Weathering and mass movement

1. Big Picture
Weathering and Mass
Movement.
• The meaning of weathering.
• What are the processes of
weathering.
• What is mass movement
and how does mass
movement happen?
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of
weathering and mass movement
Weathering
 Is the breaking down of rocks
by mechanical, chemical or
biological processes in situ
(where they are).
Key Vocabulary
Page 94 -95
26 March 2019

2.  You can describe the two main types of weathering.
 You use a limited range of specialist terms
 You have a reasonable accuracy in the use of spelling,
punctuation and grammar.
 You can outline how weathering affects the cliff and aids erosion.
 You use a good range of specialist terms
 You have a considerable accuracy in spelling, punctuation and
grammar.
 You use the processes of sliding and slumping with weathering to explain why
cliffs collapse.
 You use a wide range of specialist terms where appropriate.
 Accurate use of spelling, punctuation and grammar.
Learning Outcomes – Success Criteria
L3 - Detailed
Answer
L2 - Clear
Answer
L1 - Basic
Answer
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass
movement

3. Produced by Mr M Colclough
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass
movement

4. Type of weathering Diagram Explanation
Chemical
Biological
Mechanical
Extension: Which do you
think causes most rock
breakdown? Why?
Using the information sheets complete the table to explain how the different types of weathering
work.
Grades 1-3
You describe the types
of weathering and draw
a basic diagram.
Grades 4-6
You explain the types of
weathering by clearly
giving the stages.
Grades 7-9
You create clear staged
diagrams fully labelled
to explain each type.
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass
movement

5. When the temperature rises again the ice will melt and contracts, which
releases the pressure on the rock.
Water becomes trapped in a crack or joint in the rock.
When the temperature drops below freezing, the water will freeze and expand
by 9 – 10% putting pressure on the rock.
This process repeats, the rock weakens resulting in rockfalls.
Freeze-thaw action
This is the breakdown of rock without changing its chemical composition. This occurs
when the temperature alternates above and below 0°C (the freezing point of water)
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement

6. Living things such as burrowing animals and plants attacking rocks and weakening
their structures. For example, burrowing animals such as rabbits can burrow into a
crack in a rock, making it bigger and splitting the rock. Plant roots can grow in
cracks. As they grow bigger, the roots push open the cracks and make them wider
and deeper. Eventually pieces of rock may fall away.
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement

7. Carbonic acids attack rocks changing its structure.
This includes solution. Chemical weathering occurs
when rain water which contains carbon dioxide
(making it a weak carbonic acid) reacts with the
calcium carbonate in rocks such as limestone and
chalk. This dissolves and is washed away in solution,
weakening the rock.
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement

8. Question Time
What’s the correct definition of weathering?
A) The breakdown of rock in situ.
B) The breakdown and transportation of rock.
Which statement is correct?
A) Freeze-thaw weathering is where water gets into a crack, it freezes
and expands the rack, when it thaws, water gets deeper into the
creak, this is repetitive and eventually the rock breaks up.
B) Freeze-thaw weathering is where it rains making cracks widen and
weak so the rock breaks up.
Which statement is correct?
A) Carbonation weathering is where H₂O reacts with CO₂ creating acid
rain. Acid rain reacts with calcium carbonate (CACO₂) creating
calcium bicarbonate Ca(HCO₃)₂ which dissolves the rock.
B) Carbonation weathering is where H₂O reacts with calcium carbonate
(CACO₂) to create calcium bicarbonate Ca(HCO₃)₂ which dissolves the
rock.
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement

9. Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass
movement
Key Vocabulary
Mass Movement
 The shifting of rocks of loose material down a slope such as a cliff
collapse. It happens when the force of gravity acting on a slope is
greater than the force supporting it. This process causes the cliff
to retreat (move back).

10. Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass
movement

11. Produced by Mr M Colclough
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass
movement
Mass
Movement
Poster
Use your A4 sheet of paper
to make a poster revision
resource about the
different types of mass
movement. Include a
diagram and description.

12. Slide plane
Detached rock
Bedding of rocks
Divide your A4 sheet into four and draw and explain the different types of mass movement.
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement.

13. Rockfall is the rapid, free-fall of rock from
a steep cliff face. Rock fragments fall from
the face of the cliff because of the action
of gravity. This is made worse by freeze-
thaw action loosening the rock. Bare, well-
jointed rock is very vulnerable to rockfall -
water enters the joint, freezes and
expands, cracking the rock. A scree slope
of fallen rock is formed at the bottom of
the cliff.
Mudflow occurs on steep slopes over
10°. It's a rapid sudden movement
which occurs after periods of heavy
rain. When there is not enough
vegetation to hold the soil in place,
saturated soil flows over impermeable
sub soil, causing great devastation and
endangering lives.

14. A landslide occurs when blocks of rock
slide downhill. Falls occur due to loss of
support they involve free falling of
blocks of different sizes detached from
rock slopes in the form of rolling or
sliding. Depending on the type of
material it may be rock, debris and earth
falls.
Rotational slips or landslips are
occasional, rapid movements of a mass
of earth or rock sliding along a concave
plane. They can occur after periods of
heavy rain, when the water saturates
overlying rock, making it heavy and
liable to slide. Undercutting of a steep
slope by river or sea erosion weakens
the rock above, also making a slump
likely.
Slide plane
Detached rock
Bedding of rocks

15. Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement.
Beachy Head 2001
Tasks
1. Label the rockfall, chalk cliffs,
rocky beach.
2. Do you think Freeze Thaw
weathering is happening here
here?
3. How might rockfalls be a hazard to
people?
4. What conditions may have caused
this rockfall?
Write In full sentences. Make
sure your arrows touch the
feature in the photograph.
Key Skill: Photograph Interpretation

16. The amount of weathering and mass movement that occurs will be
dependent on…
 Rock type
 Climate
 Structure of rock
 Vegetation
Extension: Explain how each factor affects the
amount of weathering and mass movement that
occurs.
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement.

17. 1. A prolonged period of hot and wet
weather allows vegetation to grow
rapidly
3. People build settlements of top of
unstable cliffs, putting pressure on
them
2. People build homes close to the
cliff edge to get a clearer view of the
sea from their window
4. Layers of different rock type allow
water to seep in the dividing line
between two rock types
Extension: What can be done to
prevent or slow down weathering
and mass movement?
1. Decide whether these factors are human or physical
2. Explain how each will worsen weathering or mass movement. Use the 6 types we have learnt today in
your answer
Weathering and Mass Movement
LO: To develop greater knowledge of the processes of weathering and mass movement.