Transcript The Theory of Plate Tectonics Chapter 1 Section 5

Vocabulary
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Plate
Scientific theory
Plate tectonics
Fault
Transform boundary
Diverent boundary
Rift valley
Convergent boundary
The Theory of Plate Tectonics
Chapter 1 Section 5
What is Plate Tectonics?
In 1965, J Tuzo Wilson put together Wegner’s
theory of continental drift and Hess’ theory
about sea-floor spreading into one big theoryPlate Tectonics
Plate Tectonics is the theory
that states that pieces of
Earth’s lithosphere are in
constant, slow motion, driven
by convection currents in the
mantle.
Confused?
I’ll explain.
These pieces of the lithosphere
are called plates or tectonic
plates.
The plates are always
moving in slow motion.
So what moves them?
Scientists think that
convection currents
inside the mantle do!
Plate Tectonics is the theory
that states that pieces of
Earth’s lithosphere are in
constant, slow motion, driven
by convection currents in the
mantle.
As the plates move
around they collide,
pull apart and grind
past each other!
Plates collide
at
convergent
zones
The Cascades were formed at a
convergent zone
Many volcanic islands are
formed at convergent zones.
So were the Himalayas!
Do you see how?
Plates move apart,
or divide, at
divergent
boundaries.
The mid- ocean ridge is a
divergent boundary.
Plates slide past
each other at
transform
boundaries.
Crust is neither
created or destroyed
at transform
boundaries.
3 boundaries are convergent,
divergent and transform!