The Earth - plate tectonics
Sources - GCSE Geography AQA A Specification - Revision
(For those who prefer it in a mind map or don't have a revision guide)
The Inner Core is a solid ball of
iron and nickel. The Outer Core is
molten rock (as well as the Mantle)
The Earth's crust is very thin (aprox. 20 km)
The three types of plate margin.
Here is a
diagram of a
Destuctive plate
margin...
Destructive plate margins are where two plates are moving towards
each other. When a oceanic plate and a continental plate collide,
the denser plate (oceanic plate) is pushed down and destroyed in
the mantle and usually creates an ocean trench. When two
continental plates collide, no crust is destroyed although this is
sometimes where mountains are created.
Here is a
diagram of a
Constructive
plate margin...
Construction margins are where two
plates are moving away from each other
causing magma to rise from the cracks
and when it cools, new crust is formed.
Here is a
diagram of a
Conservative
plate margin...
Conservative plate margins are where two plates are
moving sideways past each other or moving in the same
direction but at different speeds. Here, no crust is made nor destroyed.
Continental Crust - thinker and less dense.
Fold Mountains
How are they made?
Fold mountains are created when tectonic plates
collide. The sedimentary rocks that have built up
between them are folded and forces upwards to form
mountains.
Where are they found?
Fold mountains are found at
destructive plate margins and places
where they used to be. You can also
get them where continental and
oceanic plates collide as well as
where two continental plates collide.
How humans use fold mountains...
Farming
Higher mountain slopes are used to graze animals as they are terrible for growing
crops. Low slopes are used for growing crops and steep slopes are sometimes
terraced to make growing crops easier.
Mining
Mining is great as the fold mountains produce
plenty of metal ores. Steep slopes are not very
easy to mine so roads are carved into the sides
of them to get around easily.
Hydro-Electric Power
Steeps sides and high rivers make fold mountains ideal for generating
electricity using massive dams with turbines that spin as the water pours
through.
Tourism
Many tourists come here for winter skiing and
snowboarding as well as summer hikes and camping.
There are some tunnels in the fold mountains - carved
to make the straight and fast roads available. With
these communications, many more people are aware
of the beautiful scenery available here.
Forestry
Fold mountains are really good
for growing certain types of trees
such as conifers. They are grown
on steep slopes and are used for
building, fires, paper, furniture
and fuel.