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The world around us
Where does
rock come from?
1
What different types of rock do you
know about?
R E A D & T H I N K
Rock
The Earth’s crust is made up of rock. There are three main different types of rock:
igneous
,
sedimentary
and
metamorphic
.
Igneous rock
Sedimentary rock
Metamorphic rock
This rock is deep inside the Earth. It’s very
hot here and the rock melts. When there is a
volcanic eruption, this hot rock is blown out
by force from the Earth’s mantle, the layer
underneath the crust. When the melted rock
cools down, it makes igneous rocks such as
granite
and
basalt
. They are often found in
landscapes with large stone structures.
Sedimentary rock is made of fragments of
rocks, dead vegetation and animal matter
which have settled onto the Earth’s surface and
formed a solid mass. It is most often found at
the bottom of lakes and oceans. It usually forms
layers.
Sandstone
,
shale
and
coal
are some
examples of sedimentary rocks.
Metamorphic means a change of form.
Metamorphic rock forms when there are
movements in the inner layers of the Earth.
Heat and
pressure
act on other rocks and
change them into metamorphic rocks.
Marble
and
slate
are examples. Marble is formed from
clay and slate is formed from limestone.
