Spot the difference!
Lesson Objectives
This lesson we will be looking at types of mass movement and weathering.
By the end of this lesson you will be able to:• Name 3 types of weathering and two types
of mass movement• Describe how weathering causes mass
movement• Explain slumping
Weathering and ErosionWeathering and Erosion
Weathering – the breaking down of rock without any involvement of moving forces
Erosion – the breaking down of rock by a moving force such as a wave
Clay
Erosion by waves
Saturation by rainfall (ground cannot hold anymore water
Rotational Slumping
Mass MovementMass Movement• Bottom of the cliff eroded by waves and undercut
• Rainfall saturates cliff and makes it heavier
• Water trapped between layers of rock in the cliff acts like a lubricant
• Rocks slide down cliff in a rotational manner
• Often happens in clay
• Rocks are weathered on the cliff face
• They break loose and fall under the influence of gravity
Coastal WeatheringCoastal WeatheringSalt Crystal Growth Acid Rain Biological
Sea water contains salt.
When water lands on rocks, the water
evaporates leaving salt.
As this process repeats the crystals grow putting
pressure on the rocks causing it to break down into smaller fragments
All rain is slightly acidic.
Polluted air can be very acidic
When rain falls on rocks, the acid reacts with some
of the minerals causing them to dissolve
The roots of vegetation grow into cracks in the
rock.
This splits the rock apart.