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IGNEOUS ROCKS
It comprises 95% of the Earth’s crust.
How do igneous rocks form?
Magma - Solidification of Lava - Igneous Rocks
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There are two types of Igneous Rocks
Intrusive Igneous Rocks (PLUTONIC)
Magma cools down and solidifies inside the earth’s surface.
%%Slow cooling = Large crystals%%
Examples of Intrusive Igneous Rocks:
Diorite: It is a mixture of feldspar, pyroxene, hornblende, and sometimes quartz.
Gabbro: It contains feldspar, pyroxene, and sometimes olivine.
Granite: it contains mainly quartz, feldspar, and mica minerals
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Extrusive Igneous Rocks (VOLCANIC)
Magma cools down and solidifies above the Earth’s surface
%%Fast cooling = small crystals%%
Examples of Extrusive Igneous Rocks:
Andesite: It is composed mainly of plagioclase with other minerals such as hornblende, pyroxene, and biotite.
Basalt: it is composed mainly of plagioclase and pyroxene.
Obsidian: forms from the very rapid cooling of molten rock material. It cools so rapidly that crystals do not form.
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SEDIMENTARY ROCKS
Comprised of Sediments
Lithification: it is a %%complex process%% whereby freshly deposited loose grains of sediment are converted into rock.
How do Sedimentary rocks form?
Lithification processes:
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3 CLASSIFICATIONS OF SEDIMENTARY ROCKS:
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METAMORPHIC ROCKS
When igneous rocks and sedimentary rocks are %%exposed to high temperature and pressure.%%
Metamorphism: change from one rock formation to another.
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