plate tectonics unit 3 mark scheme for corrections

1. Mini test 3
Mark Scheme

2. 1. Study Fig 1 and Fig 2 below which shows two fold mountains.
Use what you observe in Fig 1 and Fig 2 to help describe the
appearance and characteristics of fold mountains. [6]
• Figure 1
– Cross section of the fold mountain.
– Clear folding shown
– Upfold and downfolds / anticline and syncline
• Figure 2
– Show capped mountain top
– Indication of tall height, typical of fold mountains
– Fold mountains result from massive compression,
forming great heights.

3. 2 (a) Explain how a Tsunami is formed and why Singapore is
unlikely to suffer a Tsunami if there are tectonic movements
along the Sumatra Trench.
• Sudden uplifting of underwater tectonic plates
• Water above is pushed upwards and moves
outwards
• Tsunami grows if fetch is big
• Singapore is sheltered by the island of
Sumatra
• Tsunami triggered off the Sumatra Trench will
have to overcome the island of Sumatra to
have an impact on Singapore.

4. 2(b) Using only a fully labelled diagram, explain what occurs
when an oceanic plate converges with a continental boundary.
Include an example of where you can find such a tectonic
landform.
Deep Sea Trench

5. 3(a) With the aid of a fully labelled diagram, explain
how the Mid-Atlantic Ridge was formed.
• Area where two oceanic
plates move away from
each other
• Magma moves up to the
surface and cools to form
new oceanic crust
• Mid-Atlantic Ridge
• Possible to find
underwater volcanoes at
such locations

6. 3(b) With the aid of a fully labelled diagram, explain
how Block Mountains are formed.
• When sections of the
crust are pulled apart by
tensional force, some
parts are ripped off.
• The downward
displaced areas are the
rift valleys
• The blocks left behind
form block mountains
with steep sides.
• Also called Horst
Tectonic plate
shifting
downward