4.3 A Flashcards
(28 cards)
What is the rock type like on a concordant coastline?
The concordant coastline have the same rock type
What type of rocks are on a discordant coastline?
They have different layers of rocks (limestone,clay chalk)
What are Fault and joints ?
Joints- theres a small cracks found in rocks, then air gets into it during when hydraulic action happens and when water hits it the pressure increases and it expand
Faults - when the tectonic plates have moved
What are soft and hard rocks?
Hard rocks - are rocks like limestone and chalk. The headlands is an example of hard rock
Soft rock - Rocks that erodes easily e.g clay and sand. Bays have soft rocks.
Describe what are the characteristics of headlands and bays?
Headlands do not get eroded faster than the bay because its a hard rock
Bays are a soft rock which gets eroded faster
How are wave cut platforms formed?
Firstly, The wave erodes between the low and high tide mark over many years. Secondly, this will create Wave cut notch at the base weakening the cliff and create the overhang. Fourthly, the overhang collapses from its own weight and creates a wave cut platform. Fifthly,
this process will repeat.
How are arch, stumps and stacks formed?
Firstly,In the headlands there is a crack and the waves will attack the cracks in the rock secondly the crack will get bigger and a cave will form. Thirdly, it will keep on getting bigger and bigger and it will form an arch. Fourthly, further erosion will make it fall and will leave behind the stack and further erosion and weathering will cause the top of the rock to fall off which will create a stack and then it will create a stump when all all of it but a third has been fallen
Three factors that effect wave energy
Prevailing wind, winter conditions and fetch (distance)
Where does the uk have the biggest waves and why?
Biggest waves from the uk comes from the south west coast because the predominant wind comes from the south west
Characteristics of destructive waves
Destructive means to destroy and it has a bigger swash than backswash.
How is a beach formed?
Firstly waves attack headlands and some sediments (rocks and sand) gets eroded by the waves. Secondly the predominant wave will make the long shore drift move the sediments to the beach and the wave is called constructive wave (to build). Thirdly, larger rocks will be transported first and then smaller rocks.
Biological weathering.
When plants are grown in small cracks of rock causing pressure because of the roots of the plant and eventually fall off.
What is hydraulic action?
Its when the power of the wave hits cracks in the rocks and eventually water will get inside making the crack bigger and bigger.
What is attrition?
When rocks are held in the waves hitting each other making it smoother and smaller
What is solution?
When the water gets slightly acidic and dissolves rocks like limestone/chalk. (Caused by vegetation)
What is abration?
When rocks are picked up by waves and thrown against the cliff or rubbed, making the rock wear away and eventually removed .
How are headlands and bays formed?
1)sea/waves attack a part of the coast. 2) the part of the coast the sea attacks will be a soft rock. 3) sand and chalks are eroded. 4) lastly it leaves the headlands.
How does long shore drift work?
These are waves that hit the beach, it carries sediments and moves along in a zig zag pattern. Swash,is when it hits the beach and backwash is when the water drives back into the sea.
Compare biological,freeze thaw,chemical weathering.
1)Biological os caused by plants growing in the crack 2) freeze thaw is caused when ice gets into crack and expands 3) chemical weathering when acidic rain falls caused by carbon dioxide causing rocks to fall off.
How is a spit formed?
Spits are formed when prevailing wind turn at an angle which makes long shore drift moves sediments at the same angle as prevailing wind. This creates an “extended stretch”of beach material.
Describe the characteristics of a spit
1) very long 2) extended part on the coastline 3) spare land
Compare the characteristics of a spit to a bar.
1) Spits are a long extended stretch on the coast caused by prevailing wind 2) bars are a circle in the headlands and bay when the spit reaches across the bay .
What are the characteristics of a wave cut platform?
1) solid, big base 2) rocks collapsed which formed base 3) in a bit of a right angled shape(L shape).
Characteristics of arch/stacks/stumps.
Arch - almost like a bridge but has an semicircle shape caused by erosion. Stack - long, tall bit of rock caused when arches collapse stump - when the tall rock get eroded it goes smaller into just a bit rock.