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What are Igneous Rocks?
Rocks formed
from the cooling of hot
magma
are called igneous rocks.
Igneous rocks
first formed
when the Earth cooled
from
its molten state
about 4
billion years ago.
Igneous rock
is
still being made today by the process
of tectonic
activity.
How can Igneous Rocks be Identified?
Igneous
rocks contain
randomly arranged interlocking crystals.
The crystal size
depends on the rate
of cooling.
When hot
magma is cooled
quickly
it makes basalt
and when it is cooled slowly
it makes granite.
Igneous
rocks do not contain fossils because the
rock forms
at a high temperature
which would
destroy any living organisms.
Links Rock Cycle Revision Questions
gcsescience.com The Periodic Table Index Rocks Quiz gcsescience.com
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