ACE All about Rocks

This blog post is for 25/2/2011 ACE Geography lesson.

My notes are full of scribbles! Anyways, we started with the crust today. We learnt something new, and that is the land part of the crust is the continental crust, while the water part is the oceanic crust. Interestingly, they are both solid. Just then a lot of questions popped into my head. I thought the water was… well, water. Why solid? Well, the solid part would be the crust itself. The water was, well, on top of the crust, like:




I know it’s not really nice, because I drew it free hand on the computer, but I hope it helps.

Okay, just as I promised, here is the answer to “What happens if the plates hit each other?” Volcanoes and mountains form. Can you imagine that? They hit, and then they form these cool big landforms. However, that is not all. Earthquakes can occur too. Strong earthquakes, just like the one that happened in New Zealand.

That brings me to how the plates move. As the mantle moves (conventional current), the plates move in three directions, as they are floating on the Mantle, the example Ms J gave us, just like the yummy-looking, lip-smaking, stomach-worth-growling-for treat, S’more (sorry, I’m hungry!):

The cracker: Plate on Earth's crust

The melted marshmellow: Mantle

These are the three kinds of plate movement: (Once again, the diagrams are not exactly pleasant to the eyes… )
Diverge (pull away) :

Converge (move towards each other):

And lastly,
Side-by-side:

Cool right? One more thing: the plate movement leads to plate boundaries.

Then we went on to Igneous rocks. They are made of magma.
1. Granite:
It is course-grained as the magma, which takes a long time to cool, has time to ‘grow’ bigger. Why does the magma take a long time to cool? The magma cools inside the Earth and the inside of the Earth is hot.

2. Basalt:

Yes, we all know it is, obviously, fine-grained. Why? For this case, the magma hardens quickly outside the Earth, because outside the Earth is cooler than inside the Earth.

Now we move on to to Sedimentary rocks. Rocks are broken down to smaller pieces through weathering and erosion. Small pieces of sediments get carried into rivers by water and wind. They are then piled up and, under tremendous pressure, are camented together and hardened. The result? Beautiful breathtaking Sedimentary rocks. Sedimentary rocks are my favourite kind. So, here are some pictures that I think are so cool.

Then we skipped a few parts and went all the way to Metemorphic rocks. How are they formed? When the plates move, one plate can slide underneath another plate. Metemorphic rocks are formed inside of the Earth.And that was the end of the lesson.

This time, the lesson was overflowing with lots of different types of question, so many that Ms J had to stop all the overflowing questions to move on with the lesson. I have certainly learnt a lot of interesting things today, and I hope to be able to be as smart as Ms J one day!