LAYERS OF THE EARTH

HOW WE KNOW ABOUT THE DEEP INTERIOR:

MeteoritesSeismic WavesMagnetic FieldGravity

Earth’s Layers

LAYERS OF THE EARTH

The Velocity of Seismic Waves increase as theytravel through the earth

Steep decrease inVelocity of P-wave occurs inOuter Core

S-waves do not travel throughliquids

Type Relative Composition Rock Type EarthLayer

Abundance,%

Stony Meteorites 94

Chondrites 86

Ordinary 82 Fe, Mg intrusive igneous and Mantle

Silicates meta- igneous

Carbonaceous 4 Carbon, gases Crust

hydrated silicates,

up to 20% water

Achondrites 8 Fe, Mg Silicates I gneous basalt lava ocean crust

Stony I ron 1 Silicates and Fe alloys primitive

planet

I ron 5 Fe, Fe- Ni alloys Core

METEORITE COMPOSITIONS AND EARTH ANALOGUES

Earth’s Mantle consists of ultramafic rock made of two Fe, Mg Silicate minerals: Olivine and Pyroxene

Ultra-mafic Intrusive Rock

Upper Mantle: Gabbro with Pyroxene, Olivine, and Feldspars (Ca,Na)

Mafic Intrusive Rock

Ocean Crust: Basalt

Mafic Extrusive Rock

Continental Crust: Granite

Felsic Intrusive Rock

Outer Layers of Earth

ESS Processes often involve the whole earth over time:lithosphere-

atmosphere-hydrosphere