This document provides information about the structure and composition of Earth's layers. It describes the crust, mantle, and core. The crust is divided into continental and oceanic crust based on their chemical composition. Below the crust is the mantle, divided into the solid upper mantle and semi-liquid lower mantle. The innermost layer is the core, with the liquid outer core surrounding the solid inner core made of nickel and iron.

1. EMMANUEL
COLLEGE OF B.Ed
TRAINING,
VAZHICHAL

2. UNIT - 3
IN SEARCH OF
EARTH’S
SECRETS

3. CONTENTS
1. Crust
Continental Crust & Oceanic Crust
2. Mantle
Upper Mantle & Lower Mantle
3. Core
Outer Core & Inner Core

4. CRUST
- The comparatively thin outer
shell
of the Earth.
- Approximately 40 km thick.
- Two parts- continental crust &
oceanic crust.

5. Continental crust and
oceanic crust
• As silica and alumina are the chief
contents,
the continental crust is also known
as SIAL.
• As silica and magnesium are the
chief contents, the oceanic crust is
also known as SIMA.

6. MANTLE
• Located beneath the crust.
• Extends upto 2900 km from
the
crust.
• Two parts- upper mantle, lower
mantle.

7. Upper mantle and Lower
mantle
Upper mantle
• The upper mantle, made up of silicon
compounds, is in a solid state.
Lower mantle
• The lower mantle, located beneath the
upper mantle, is in a semi-liquid state.

8. CORE
• Central part of the Earth.
• From 2900 km to 6371 km
• Two parts- outer core, inner core.

9. Outer core and inner core
• The materials in the outer core are in a
molten state.
• Due to the high pressure prevailing at
the centre, the inner core is in a solid
state.
As it is mainly made up of the minerals
nickel (Ni) and iron (Fe), it is also
known as NIFE.

10. THANK
YOU