Download Plate tectonics: The main features are

Plate Tectonics
 First proposed by Alfred Wegener in 1912
- All continents were once joined together in a super-continent
called Pangaea
- The continents separated into two large continents.
- One moved to the northern hemisphere – Laurasia
- The other moved to the southern hemisphere – Gondwanaland
Plate tectonics: The main features are:
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The Earth's surface is made up of a series of large plates (like pieces
of a giant jigsaw puzzle).
These plates are in constant motion travelling at a few centimetres
per year.
The ocean floors are continually moving, spreading from the centre
and sinking at the edges.
Convection currents in the mantle beneath the plates move the plates
in different directions.
The source of heat driving the convection currents is radioactive
decay which is happening deep in the Earth.
Evidence for Continental Drift
 Continents can be pieced together like a jigsaw puzzle.
 Rock formations
 Fossils
Subduction Zones
 Where one plate slides beneath another
Divergent Zones
 Mid ocean ridges – Marianas Trench
 Rift Valleys
Transverse Faults
 One plate sliding past another – San Andreas Fault. It forms the
tectonic boundary between the Pacific Plate and the North American
Plate.