Earth’s Interior & Plate Tectonics

Inside the Earth

The Earth’s Interior

Inner Core• Solid

• Iron & Nickel

• 5000°C

• 5150 km deep

• 1300km thick

Outer Core• Liquid

• Iron & Nickel

• 2200°-5000°C

• 2900 km deep

• 2250 km thick

MantleThick liquidSilicon, oxygen,

iron & magnesium

870°-2200°C2900 km thickMoho-boundary

between outermost layer

and mantle

Crust• 3 types of solid rock

– igneous, sedimentary, & metamorphic

• Oxygen & Silicon• Oceanic crust 8 km

thick-basalt• Continental crust

32km thick-granite & basalt

Elements in the Earth’s Crust

• Oxygen 46.6% • Silicon 27.72%• Aluminum 8.13%• Iron 5.00%• Calcium 3.63% • Sodium 2.83%• Potassium 2.59%• Magnesium 2.09%• Titanium 0.40%• Hydrogen 0.14%

Lithosphere• Top most

solid part of the earth

• Broken up into 7 major lithospheric plates

Plates

Plate Tectonics

Theory of Continental Drift

• 1900’s Alfred Wegener proposed that the earth used to be one giant landmass that split to form today’s continents

Fossil Evidence

• Fossils support Wegener’s theory.

• Glossopteris

• Mesosaurus• Lystrosaurus

• Cynognathus

Rock Evidence

• Glacial Deposits

• Folded Mountains

• Coal Deposits

Convection Cells

Boiling Water

Ocean-Floor Spreading