The Earth is made up of concentric layers, like an onion. The outermost layer is the crust, which is thinnest and varies in thickness between continental and oceanic crust. Below the crust is the mantle, which extends almost 3,000 km deep. The innermost layer is the core, with a liquid outer core and solid inner core composed mainly of nickel and iron. Rocks make up the crust and can be categorized as igneous, sedimentary, or metamorphic depending on how they were formed from molten magma or through other geological processes.

1. INSIDEOUREARTH

2. ABOUTTHEEARTH
• The Earth, our
homeland is a dynamic
planet.
• It is constantly
undergoing changes
inside and outside.

3. INTERIOR OF THE EARTH
Just like an onion, the Earth is made up of
several concentric layers with one inside
another.
EARTH ONION

4. INTERIOR OF THE EARTH
CRUST
LITHOSPHERE
MANTLE
CORE-MANTLE
BOUNDARY
OUTER CORE
INNER CORE

5. CRUST
• The uppermost layer
over the earth’s surface
is called the crust.
• It is the thinnest of all
the layers.

6. Continental Crust and Oceanic Crust
• Crust is about 35 km.on the
continental masses and only 5 km.on
the ocean floors.
• The oceanic crust mainly consists of
silica andmagnesium; it is
thereforecalled sima (si-silica andma-
magnesium).
• The main mineral constituents of
thecontinental mass are silica and
alumina. It is thus called sial (si-silica
and al-alumina).
CONTINENTAL CRUST
CONTINENT
OCEAN
OCEANIC
CRUST

7. MANTLE
• Just beneath the crust
is the mantle which
extends up to a depth
of 2900 km. below the
crust.
MANTLE
CRUST

8. CORE
• The innermost layer is the
core with a radius of about
3500 km. It is mainly made
up of nickel and iron and is
called nife (ni – nickel and
fe – ferrous i.e. iron).
• The central core has very
high temperature and
pressure.
LIQUID
OUTER
CORE
SOLID INNER
CORE
CRUST
MANTLE

9. ROCKS AND
MINERALS
• The earth’s crust is made
up of various types of
rocks. Any natural mass of
mineral matter that makes
up the earth’s crust is
called a rock. Rocks can be
of different colour, size and
texture.

10. TYPES OF ROCKS
There are 3 major types of rocks-
IGNEOUS ROCKS
1.
2.
3.
SEDIMENTARY ROCKS
METAMORPHIC ROCKS

11. IGNEOUS ROCKS
• Igneous: Latin word
Ignis meaning fire.
• When the molten magma
cools, it becomes solid.
Rocks thus formed are
called igneous rocks. They
are also called primary
rocks.