tibet 4 continental collision k co

What’s this?

Himalaya / Tibetan Plateau formation – key words starter

1. Sediment

2. Ammonite fossil

3. Deposition

4. Limestone

5. Erosion

6. Plate

7. Rigid

8. Folding

9. Fault

10.Subcontinent

11.Plasticity

12.Subduction

a) The remains of a curly-wurly sea creature preserved in the rocks

b) Bits of sand, mud, shells, etc.

c) When sediment falls to the bottom of the sea

d) When rocks get worn away

e) When layers of rock bend

f) A rock formed mainly of sea-shells

g) Line along which rock ‘snaps’

h) Hard to bend

i) One of the ‘jigsaw pieces’ of crust and upper mantle which move around the earth

j) When one plate sinks below another

k) A section of continent (usually ‘sticking out’)

l) A property of a substance whereby it squashes rather than snaps when out under pressure

Learning objectives

• To be able to explain how Tibet and the Himalayas were formed...including an understanding of as many of these words / phrases as possible: - subduction - plasticity - India’s northward drift

• To be able to give evidence for this explanation...including - yellow limestone - ammonites - satellite measurement

Can you remember how Tibet / The Himalayas were

formed?

Amazing Earth – Himalaya Rising

(130 Mya)

On these two pictures, think about what happens to the sediment in the bottom of the disappearing ocean (can you predict?)

So, what has happened to it?

Truth is, some has gone down here (subducted), and…

…some has been squashed right up here, to the top of the highest mountains

Click for animation

video

Both of these things are important in understanding plate tectonics.

The subducted sediment (and water) is what causes the melting (and so the volcanoes), by adding impurities to the mantle (like adding salt to ice)

The sediments being squashed to the top result in the amazing truth that the highest mountains are made from material from the bottom of the ocean.

What is this fossil called?

Ammonites like this are found in the Himalayas.

This is how they lived when they were alive.

They lived in the oceans. So how come they are found in the highest mountains?

After Collision

You can see on this slide that the continental rocks get ‘squashed’ when they are put under great pressure (and buried, so they heat up).

Geology teachers often say it behaves like plasticine.

This is an important thing to understand about continental rocks: when heated and pressurised, they behave plastically (i.e. they squash not snap – unlike the oceanic crust, which does not squash – i.e. it is rigid.)

Indian plate

Eurasian plate

This is getting ‘squished’ sideways!

Where is the Indian plate?

What is the name of the other plate?

Which direction are they moving?

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The formation of Himalaya / Tibet

Labelling activity: Match the numbers to the following labels (put the correct number in the squares)

□ Tibet

□ impurities from subduction causing melting

□ India

□ Asia

□ plastic continental rocks being folded

□ rigid oceanic plate

□ uplifted sediments from ocean floor

□ Himalayas

□ sediments being deposited on ocean floor

□ volcanoes

NAME: ........................................

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1

1

2

68

3

7

9

10

5

4

The formation of Himalaya / Tibet

Labelling activity: Match the numbers to the following labels (put the correct number in the squares)

□ Tibet

□ impurities from subduction causing melting

□ India

□ Asia

□ plastic continental rocks being folded

□ rigid oceanic plate

□ uplifted sediments from ocean floor

□ Himalayas

□ sediments being deposited on ocean floor

□ volcanoes

8

3

1

2

9

10

7

6

5

4

8

3

1

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1

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1

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9

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7

10

9

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1

8

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6

7

10

9

2

1

8

3

5

4

6

7

10

9

2

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3

Learning objectives

• To be able to explain how Tibet and the Himalayas were formed...including an understanding of as many of these words / phrases as possible: - subduction - plasticity - India’s northward drift

• To be able to give evidence for this explanation...including - yellow limestone - ammonites - satellite measurement