Plate tectonics axb
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Transcript of Plate tectonics axb
The interior structure of the earth
The interior structure of the earth
• The crust and part of the upper mantle = lithosphere– about 100 km thick –Less dense than the material below
it so it “floats”
The interior structure of the earthThe Lithosphere
• The plastic layer below the lithosphere = asthenosphere
• The plates of the lithosphere float on the asthenosphere
The interior structure of the earthThe Asthenosphere
• Two types of crust:
•Continental•Oceanic
The interior structure of the earthThe Crust
• Differences between oceanic crust and continental crust?
• Continental crust is composed of granite while the oceanic crust is composed of basalt.
• The density of the continental crust is less than the oceanic crust, thus it floats higher on the mantle.
How this tears the surface apart
In 1912 a German scientist named Alfred Wegener proposed the theory that the crustal plates are moving over the mantle. This was supported by fossil and rock type evidence; also matching of coastline shapes.
Pangaea
The Spreading Continents
Plate Boundaries Map
Major plates only
Plate Boundaries Map
Types of Plate Boundaries
Types of Plate Boundaries
Rift Valleys - ccd
Oceanic Convergence
Oceanic to Continental Convergence
Continental Collision
Transform Faults
The future?