Layers of
the Earth
Earth’s
Interior
Chemical
Make-up of Layers
-
3 Main Layers
o
Crust: outermost layer
o
Mantle: middle
layer
o
Core: center layer
-
Made up of different chemicals
o
Crust and Mantle
§ Contains
rocky materials: silicates
· Silicates=
compounds of silicon and oxygen
· Crust
silicates= rich in aluminum, iron, magnesium
· Mantle
silicates: mostly iron and magnesium
o
Core
§ Made of 2
metals: iron and nickel
-
Temp. is hot but Earth’s interior is not liquid
o
Pressure is so high, matter will not melt
-
Temp. and pressure vary with depth
o
Increases as get closer to center
o
Matter can be solid, liquid, in-between
§ Lithosphere:
outer zone; cool and rigid; crust/upper mantle
§ Asthenosphere: hot and semi-liquid; mantle
-
Has a layered structure
o
Crust and upper mantle
o
Crust has 2 parts
§ Oceanic
crust: under oceans
§ Continental
crust: under continents
§ Both on
top of lithosphere
-
Continental Crust
o
Less dense than oceanic
o
Higher % of silicon and oxygen with more aluminum
o
Rocks= mostly granite and rhyolite
o
Varies in thickness
§ i.e.:
tall mountains have deep “roots”
-
Oceanic Crust
o
More dense (has to hold oceans!)
o
Rocks: mostly basalt and gabbro
§ Denser
and darker