Processes Of Coastal Weathering Mass Movement Erosion and Associated Landforms

Question 1

What are the 4 sub aerial erosion processes?

Answer 1

Physical/mechanical weathering
Chemical weathering
Biotic weathering
Mass movement

Question 2

What are the 4 marine erosion processes?

Answer 2

Hydraulic action
Corrasion/abrasion
Attrition
Corrosion

Question 3

Define weathering

Answer 3

The disintegration and breakdown of rocks in situ by the action of the weather, plants and animals

Question 4

3 types of physical/mechanical weathering

Answer 4

Freeze thaw
Salt crystallisation
Water layer weathering

Question 5

Define freeze thaw

Answer 5

Repeated freezing and thawing of water results in the expansion of cracks In rocks causing small fragments to break off

Question 6

Define salt crystallisation

Answer 6

Sea water evaporates from cracks allowing salt crystals to grow, exerting pressure and causing pieces of rock to break off

Question 7

Define water layer weathering

Answer 7

Constant wetting and drying (eg due to tides) causes clay rich rock to expand and contract resulting in cracks which aid physical weathering processes

Question 8

6 types of chemical weathering

Answer 8

Solution 
Oxidation
Hydration 
Hydrolysis 
Chelation 
Carbonation

Question 9

Define solution

Answer 9

The removal of rock dissolved in acidic rain water

Question 10

Define oxidation

Answer 10

Oxygen dissolved in water reacts with minerals causing oxidation

Question 11

Define hydration

Answer 11

Minerals in rocks absorb water which weakens their structure making them susceptible to weathering

Question 12

Define hydrolysis

Answer 12

Breakdown of rock by acidic water (eg from carbonation) produces clay and soluble salts especially feldspar in granite

Question 13

Define chelation

Answer 13

Organisms produce substances called chelates which decompose minerals

Question 14

Define carbonation

Answer 14

Carbon dioxide dissolved in rain water creates weak carbonic acid, which dissolves calcium carbonate in limestone.

Question 15

What are the 2 types of biotic weathering processes ?

Answer 15

Plant growth

Animals

Question 16

Define plant growth

Answer 16

Roots of growing plants force their way into cracks and joints in the rock increasing the pressure and causing rock particles to fracture

Question 17

Define animals

Answer 17

Burrowing animals create weaknesses in soft rocks

Question 18

What are the 6 types of mass movement and their speeds?

Answer 18

Rapid-
Landslide, rockslide
Variable speed- 
Rotational slip, slump/mudslide
Slow-
Soil creep, solifluction

Question 19

Define landslide

Answer 19

Rocks affected by physical weathering or marine erosion collapse downwards

Question 20

Define rockslide

Answer 20

Rocks slide down a cliff face when the bedding planes dip towards the sea

Question 21

Define rotational slip

Answer 21

Softer rocks give way, moving downhill in one mass along a concave slip surface

Question 22

Define slump/mudslide

Answer 22

Saturated soft rock flows downhill

Question 23

Define soil creep

Answer 23

Soil particles move downslope aided by rain drop impact

Question 24

Define solifluction

Answer 24

Movement of wet soil downslope caused when underlying layers are frozen

Question 25

Define hydraulic action

Answer 25

Breaking waves create hydraulic pressure in joints. Air in cracks in a cliff face can be compressed by the force of the waves and then rushes out when the wave retreats. This can weaken the rock

Question 26

Define wave quarrying

Answer 26

High energy waves can exert a force of many tonnes per metre squared, which can remove loose, unconsolidated rock fragments

Question 27

Define abrasion/corrasion

Answer 27

Rock fragments wear away the coast. Abrasion involves rock particles being scraped over bare rock, wearing it away and smoothing it. Corrasion occurs when waves hurl debris against the rock, causing pieces to be broken off and wearing it away

Question 28

Define attrition

Answer 28

Eroded rocks are worn smaller and rounder by constant rubbing against each other with the movements of the sea

Question 29

Define corrosion/solution

Answer 29

Weak acidic sea water chemically attacks certain rocks, dissolving minerals

Question 30

What processes is a cliff affected by and how is it affected?

Answer 30

Geology- harder rocks produce steeper cliffs, softer rocks form lower angled cliffs
Structure- the dip of the bedding planes influences the angle of the cliff

Question 31

Process of cliff retreat and formation of wave cut platform

Answer 31

Marine erosion creates a wave cut notch at the cliff base.
The cliff is undercut, collapses and the process repeats.
The cliff retreats, leaving a gently sloping surface, (1-5*) called a wave cut platform. Aka intertidal shore platform.
A wave cut platform prevents marine erosion processes reaching the cliff foot except in storms or the highest tides, reducing the rate of erosion.
Sub aerial processes continue working on the cliff face, reducing the angle of slope.

Question 32

Difference between concordant and discordant coastlines

Answer 32

Discordant- bands of different rock types lie at right angles to the shoreline

Concordant - beds of different rock lie parallel to the shoreline

Question 33

Cave, arch, stack, stump sequence

Answer 33

Marine erosion processes create sea caves along a line of weakness
Further erosion results in caves either side of a small headland meeting forming an arch
Over time the arch becomes unstable and collapses, leaving an isolated pillar of rock - a stack
Erosion processes attack the stack causing it to collapse leaving a stump

Question 34

Cave, blowhole, geo sequence

Answer 34

Marine erosion processes create sea caves along a line of weakness
Waves force air and water into the cave, creating a shaft upwards to the surface and forming a blowhole where water gushes out in a certain tide and wave condition
Continued erosion causes the extended cave roof to collapse, leaving a long, narrow inlet - a geo. Geos can also form along a line of weakness, where erosion processes have a greater impact