Jason

Practical 1 – ‘Plates that seperate’.

Conclusion

In the end my hypothesis was correct, we have successfully modelled the mid-ocean spreading tectonic plates in the classroom. From this practical we learn that when two plates have seperated new rock is formed and old rock is pushed further out. The new rock (Magma & heated material) is pushed out of the faultline and is then cooled down by the ocean water, solidifying it and causing it to sink down as newly formed rock.

Questions

1. Explain how this activity relates to the spreading at the mid-ocean ridges.

Just like a mid-ocean ridge, the two plates are replaced by two desks and the magma or new rock is replaced by the paper. As the paper is pushed out and spreads outwards with a downward slant it reanacts what exactly happens underwater when plates seperate underwater.

2. Identify what in your model represents each of the following:

a. Ocean floor or plate- The desk

b. The water- The desk

c. The Lava Flow- The layers coloured on the paper

d. Gravity- The force of your hand

e. Mid-ocean ridge- The split in the middle

f. Magnetic strips found in rocks parallel to mid ocean ridges- Parallel to the lines drawn

3. Describe what you noticed about the height of the paper as it emerged from the gap compared to the paper further out.

As the paper came out it rose high but then started to slant downards as it came out symbolising the magma being cooled into rock and the rock slowly falling down to the ground. The further the paper went the lower it became till it couldn’t get any lower.

4. Identify which of the strips you coloured would be the oldest rock and which the youngest rock.

The strip the furthest away from the split would be the oldest rock and the ones closest would be the youngest rock. When new rock is formed they push the old rock out further.

5. Identify which of these strips would be the first to be swallowed by an ocean trench.

The oldest strips would be the first to be swallowed by a trench. As they are first in line towards a trench and infront of all the other new rock.

Practical 2 – ‘Colliding plates’

Conclusion

My hypothesis for this experiment was correct, we have properly modelled what happens when two tectonic plates collide. This experiment teaches us how when pates collide, landmass can be pushed in a variety of directions depending on the factors. It gives us a practical representation of plate tectonics.

Questions

1. Compare the above tests with plate tectonics.

Each test represents a type of plate tectonics (i.e collision boundary). The first test shows a plate colliding with another plate which causes folds of mountains. The second one shows a faster plate going below a slower plate which can cause the some islands to be formed. The third one shows a continental plate going over a oceanic plate because an oceanic plate is more dense and heavy.

2. The stack of paper had obvious layers. Assess whether rock has layers, and if so explain.

Rocks do have layers, different layers can be made from minerals or other substances i.e. fossils collected on the rock.

3. State which tests simulated the following conditions:

a. Continental plate wiht another continental plate- Test 1

b. An oceanic plate with another oceanic plate- Test 2

c. An oceanic plate with a continental plate- Test 3

4. Identify a place on Earth where each of these collision types occurs.

Test 1- Asia (Himalayan region)

Test 2- Indonesia

Test 3- Andes Mountain range