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The Earth’s Crust

Page 10 (Inside Earth)


·        The thinnest, outermost layer.

·        Made up of Sedimentary, Igneous and Metamorphic rock

·        The rocks on the upper crust are mostly sedimentary

·        Two types of Crust:

·        Oceanic Crust: The crust found beneath the Oceans

o       made mostly of Basalt-a darker, fine-texture heavier igneous rock

o       It is thinner (only 8 km)

o       Made mostly of silicon, oxygen and magnesium

o       Heavier and more dense

·        Continental Crust: The crust found on the continents and at the beginning of the oceans (continental shelf):

o       made mostly of Granite-a light colored coarse textured igneous rock

o       It is thicker (especially in mountainous areas) – Up to 70 km thick

o       Made mostly of Silicon, Oxygen, Aluminum, Iron, Calcium, Sodium and Potassium

o       Lighter and less dense


All life on Earth exists on or within a few hundred meters of the crust.