Folding and Faulting Flashcards
Explain the global distribution of fold mountains (30m)
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Draw a diagram showing an asymmetrical fold
N/A
What is folding?
Where rock buckles and wrinkles die to pressure at destructive plate boundary. The collision force of two plates meeting forces the sedimentary rocks to bend into folds
What are the four main different types of folds and give a simple diagram showing each of them
Simple, asymmetrical, recumbant and overturned
Draw diagrams showing the formation of fold mountains
N/A
Name the two different types of convergent boundaries fold mountains occur at and explain how they form at each
Continental-Oceanic
* Heavier oceanic plate sinks down and subducts into mantle
* The pressure created causes edges of continental plate to buckle and fold into anticlines and synclines
* Creates series of fold mountains along edge of plate boundary
Eg: Andes Mountains - Nazca-South American boundary
Continental-Continental
* Increased pressure produces intense heat causing layers of rock to become ductile
* The ductile rock buckles upwards into steep anticlines and synclines
Eg: Himalayan Mountain Range - Eurasian-Indo-Australian plates
Draw diagrams showing continental-oceanic and continental-continental formation of fold mountains
N/A
When did the Caledonian folding period take place?
400m years ago
Example of Irish Caledonian mountains
Twelve Bens, Galway and Wicklow Mountains
Which plates collided during the caledonian folding period
North American and Eurasian Plates
When did the Armorican Folding Period occur?
250m years ago
Example of Irish Armorican fold mountains
Macgillycuddy Reeks
Which plates collided during the Armorican folding period
Eurasian and African plates
Which two folding periods influenced Irish geography
Armorican and Caledonian
When did the Alpine folding period start?
60m years ago
Example of mountain range and mountain formed during Alpine folding period
Himalayas - Everest, 8800m
Which two plates collided during the Alpine folding period?
Eurasian and Indian Plates
The highest mountains in the world were formed during which folding period?
Alpine
Draw a diagram of a normal fault
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Draw a diagram of a reverse fault
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Draw a diagram of a strike slip or transform fault
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Explain tension in relation to faulting and include simple diagram
- Rocks are pulled apart from both sides causing rock to stretch or break apart
- This causes the crust to sink downwards
- Key process in formation of a normal fault
What process usually occurs at a normal fault?
Tension
Explain compression in relation to faulting and include simple diagram
- Rocks are pushed together from both sides causing rock to be shortened or fracture
- Causes crust to push upwards
Which process is usually associated with the formation of a reverse fault
Compression
Explain shearing in relation to faulting and include simple diagram
- Layers of rock are moved sideways in opposite directions causing the crust to tear apart
Which process is usually associated with the formation of a transform fault?
Shearing
Define scarp
Cliff formed by vertical displacement of rock
Define throw
Distance the crust has moved upwards
Define heave
Horizontal movement of the rock
Define fault plane
Surface which the faulted rock slides along
Define hanging wall
Section of the rock that slides
Define footwall
Section of the rock that does not move
Explain how faulting influences the development of landforms (30m)
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