3. The lithosphere Acquires
itsName from the material with
which it is made(Litho’s Means
rock. Is Diversity is due to is
constituents. The constituents
of rocks are called minerals.
Rocks can be classified into
three types-Igneous,
Sedimentary, Metamorphic.
4. Igneous rocks
Igneous rocks are formed by
the molten rock material rising
through the fissures in the
crust and solidifying either on
the surface of the earth or
within the crust itself. As all
other rock types are formed
from the igneous rocks, they
are called primary rocks.
Eg:granite basalt etc.
6. Types of igneous rocks
1. Intrusive igneous :
magma pushes into
surrounding rock below
the earth’s surface. Its
Cools slower and
crystals. Eg : granite,
gabbro.
7. 2. Extrusive rocks : its forms
when magna erupts into the
earth’s surface (lava ).cool
quickly and very small or no
crystals formed. An other
name for an extrusive roks is
a volcanic roks.
8. Sedimentary rocks
Rocks undergo weathering in
course of time. The debris so
formed will be deposited in the
low regions as layers. These
materials gradually get lithified
and transformed into sedimentary
rocks. As the sedimentary rocks
are formed in layers. They are also
known as stratified rocks. Eg:
sandstone, limestone.
10. Metamorphic rocks
When rocks undergo physical
and chemical changes due to
high temperature and
pressure metamorphic rocks
are formed. Its rocks are
prominent in kerala. Eg:
marble, slate.
