Hmmm...Miss J did not come on this Thursday. Joanne and I were wondering what had happened to her. However, in her absence, she left us an assignment to do. It was about rocks. We had to fill in the characteristics of the examples of the rocks provided. In the process, we learnt about the three types of rocks and the examples of each type of rock. The three main types of rocks are the igneous, the sedimentary and the metamorphic. Two examples of the igneous rock will be granite and basalt. Granite is coarse-grained while basalt is fine-grained. So, what comes to your mind when we mention coarse or fine grained? Big rice and small rice grains? NO...When it is coarse-grained, we meant that it was big and visible, while fine-grained refers to small. These two types of igneous rocks are made up of layers of magma or what we call, lava. Their textures are rough while their physical strengths are hard.
Now lets come to sedimentary rocks. We can very easily differentiate these rocks from the others as we can see the distinctive layers made by the minerals when the pressure caused to form them into rocks. Moreover, different minerals make different rocks. Usually, sedimentary rocks are softer than igneous and metamorphic rocks and when we say that, it does not mean pillow soft, but the soft that can be easily damaged by soil erosion or storms. Three examples of the sedimentary rocks will be the conglomerate, the limestone and shale. The conglomerate and the shale sedimenary rocks are fine-grained and is made by sediments. However, limestones are made by hardened remains of animals and plants. Some of the sedimentary rocks' textures are smooth while others are rough. The pictures below will give everyone a clearer idea of what is the information about.
As we can see, the layers of sedimentary rocks are very clear and concise. Beautiful aren't they?
Let us now go to metamorphic rocks. There are two examples of metamorphic rocks I would like to introduce everybody. They are marble and gnesis rocks. They are fine-grained and made up of bands. Furthermore, they have a foilated texture. Hmmm... can anyone guess what is the meaning of foilated? Chrystal came across a term called moon rocks on the web when she was doing some research. Is moon rock just a rock collected form the moon or there is something more to just a rock on the moon?
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ReplyDeleteHey, an interesting post!I'm also really curious about the moon rock that you've mentioned.After doing a research about it, it is said that "Moon rock describes rocks that formed on the Earth's moon." But then again, since the moon is so different from Earth, how are these rocks formed?
ReplyDeleteAlison Choo 1-2
I guess moon rocks are rocks found on the moon.The term is also loosely applied to other lunar materials collected during the course of human exploration of the Moon.But this might not be true as I got it from Wikipedia.
ReplyDeleteRelating to everyone's quetion on how moon rocks formon the moon without the presence of anything, even liquid water. therefore we cannot even create sedimentary rocks on the moon. when the Moon was young and its inside was hotter than it is now, there was molten rock inside. This lead to the formation of igneous rocks on the surface. You can see them for yourself when you look up at the full moon. You will quickly notice dark areas on the face of the Moon. We call the maria (Latin for "seas," because some early astronomers thought that they might be seas). We now know that these dark, smooth areas are in fact made of basalt. Basalt is another igneous rock we see commonly on the Earth. So we know that sometime in the Moon's distant past, there were volcanic eruptions that created these maria.
ReplyDeleteYou can go to this website to source for more information though.
http://www.madsci.org/posts/archives/2000-09/969819402.As.r.html
The comment above is written by Chrystal Ng from class 1-2
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