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Plate Tectonics
Plate Tectonics
MajorDivisionsof Earth
Plate Tectonics
DifferentProperties
Plate Tectonics
Rigid
Plate Tectonics
Plastic
The outer layer is the thinnest
= Crust
Two kinds of Crust
Plate Tectonics
• continental crust:
thicker, light
(granite)
• oceanic:thinner, dense
(basalt)
Plate Tectonics
2.7g/cm³
3.3 g/cm³
• Each Tectonic Plate: Oceanic crust
or
Oceanic & Continental crust
Plate Tectonics
• Each Tectonic Plate: Oceanic crust
or
Oceanic & Continental crust
(none with continent only)
Plate Tectonics
• Oceanic crust or
Oceanic & Continental crust
Plate Tectonics
• Active continental margin:
leading edge of plate
(earthquakes, volcanoes, steep mountains)
Plate Tectonics
• Passive continental margin:
trailing edge of continent
(eroded mountains, flat plains, little activity)
Plate Tectonics
http://www.simonwinchester.com/images/map1_large.jpg
http://www.simonwinchester.com/images/map1_large.jpg
Act
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Pas
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Plate Tectonics
Classification of Plate Boundaries
Plate Tectonics
I. Divergent Boundaries: • tension = pull apart
• normal faults
Plate Tectonics
I. Divergent Boundaries: • tension = pull apart
• normal faults
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Plate Tectonics
I. Divergent Boundaries: • new ocean crust formed • mid-ocean ridge with a rift valley down the middle
Plate Tectonics
I. Divergent Boundaries:
young basin
Plate Tectonics
I. Divergent Boundaries:
mature basin
Plate Tectonics
I. Convergent Boundaries:
• compression = push
together
• reverse faults
Plate Tectonics
I. Convergent Boundaries:
• compression = push
together
• reverse faults
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Plate Tectonics
I. Convergent Boundaries:
• folding & uplift earthquakes
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Plate Tectonics
Three kinds of
Convergent Margins(Crust Type)
oc - ococ - cont.
cont. - cont.
Plate Tectonics
IIa. Ocean - Ocean
• deep sea trench
• subduction zone (recyle)
• volcanoes & uplift
Aleutians, Japan, Philippines, Indonesia
Plate Tectonics
IIb. Ocean - Continent
• deep sea trench
• subduction zone (recycle ocean side)
• volcanoes & major uplift
Plate Tectonics
IIb. Ocean - Continent
Andes, Cascades
Plate Tectonics
IIc. Continent - Continent
• collision
• no subduction, no vulconism (can't recyle continents)
• heat & pressure, folding & major uplift
Plate Tectonics
IIc. Continent - Continent
Himalayas
Plate Tectonics
III. Transform Plate boundaries
• shear = sliding past in opposite directions
• lateral movement with earthquakes
Plate Tectonics
III. Transform Plate boundaries
CaliforniaSan Andreas fault
