· 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.