Download Chapter 10 Section 3

By: Kat Kenney, Jeff Hicks, and Carissa Blanco
Plate tectonics is the theory that Earth’s crust
and upper mantle are broken into plates that
float and move around on a plastic like layer
of the mantle.
Plates are sections of Earth’s crust and upper
mantle.
The lithosphere is the rigid layer of Earth that
is about 100 km thick. It is made of the crust
and a part of the upper mantle.
The asthenosphere is the plastic like layer of
Earth on which the lithospheric plates float
and move around.
A convection current is a current in earth’s
mantle that transfers heat in Earth's interior
and is the driving force for plate tectonics.
It is also known as the cycle of heating, rising,
and cooling.
When continental plates pull apart, they can
form rift valleys.
Where oceanic and continental plates collide,
the oceanic plate plunges beneath the less
dense continental plate. As the plate
descends, molten rock forms and rises
towards the surface, forming volcanoes.
Hess’s theory that new seafloor is formed when
magma is forced upward toward the surface
at a mid-ocean ridge.
Where two continental plates collide, they push
up the crust to form mountain ranges such as
the Himalaya.
One type of plate boundary is a convergent
boundary, where plates move together.
Another type of plate boundary is a divergent
boundary, where plates pull apart. Finally,
there is a transform boundary where plates
slide past each other.
A volcano can form at a subduction zone.
When the oceanic plate plunges beneath the
continental plate, it melts. The magma rises
into the continental plate and forms
volcanoes.