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    I am revising erosion and coastal land forms and come across a concept that I really don't get. "Concordant coastlines are where the grain of the rock is parallel to the coast" Can someone explain this statement and its relevance to erosion landforms. Thanks
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    (Original post by fivebyfive)
    I am revising erosion and coastal land forms and come across a concept that I really don't get. "Concordant coastlines are where the grain of the rock is parallel to the coast" Can someone explain this statement and its relevance to erosion landforms. Thanks
    Basically rock formations can be either concordant or discordant. Concordant intrusions are parallel to layers in the rocks, and can form sills, lacoliths, and lopoliths. Discordant intrusions cut across layers and can form dykes, stocks or batholiths. I've only come across this in terms of tectonics before, but I can see how it would affect the rates of erosion as it influences the rock resistance.

    With reference to the coastal landforms, http://www.jfk.herts.sch.uk/class/ge..._learning1.htm this website may help.
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    (Original post by fivebyfive)
    I am revising erosion and coastal land forms and come across a concept that I really don't get. "Concordant coastlines are where the grain of the rock is parallel to the coast" Can someone explain this statement and its relevance to erosion landforms. Thanks
    Concordant rocks which are parallel to the sea, and move likely to form coves, for example if a tough rock is nearest the sea and gets worn in, it exposes a layer of softer rock which is easily eroded behind. But discordant rocks are at right angles to the sea so each type can be eroded, leading to headlands and bays, the headlands being the harder, less easy to erode rock, and the bays are the softer rocks.
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    I get it now, thanks to both of you.
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    Hi,

    Ive got another question :rolleyes: , why are chalk and limestone vunerable to rotational slides (mass movement)?

    Thanks
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    (Original post by fivebyfive)
    Hi,

    Ive got another question :rolleyes: , why are chalk and limestone vunerable to rotational slides (mass movement)?

    Thanks
    The power of the waves can cause undercutting of the rocks to form a wave cut notch. The top of the cliff cannot be supported so collapses.. I think.
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    That makes sense, thankyou. Coasts is my weakest topic, my exam is on Tuesday so i am cramming!
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    (Original post by fivebyfive)
    That makes sense, thankyou. Coasts is my weakest topic, my exam is on Tuesday so i am cramming!
    Good luck! The only reason i know *anything* about coasts is because my exam was on it on monday, so i was forced to learn it :rolleyes:
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    Can anyone suggest answers to this; Why is the coast a dynamic system? All i can think of is that is is constantly changing daily and that it has many inputs.
 
 
 
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