๐TOPIC 01:STRUCTURE OF THE EARTH
[PHYSICAL GEOGRAPHY]
The earth is a system which is composed of two zones. These are
1) Outer zone
2) Inner zone
Thus, the structure of the earth consists of external structure and internal structure.
INTERNAL STRUCTURE / CONCENTRIC ZONE OF THE EARTH
The internal structure of the earth consists of three zones. These are
i) Lithosphere/crust ii) Mesosphere/Mantle iii) Barysphere / Core.
LITHOSPHERE / CRUST
Is the outermost and thinnest zone of the earth which is found between 8 – 50 km or 5 – 30 miles.
It is largely composed of igneous rocks.
Other types of rocks also exist as a result of changes on the earth’s surface. When subjected to forces or any stress.
Igneous rocks are hard and brittle.
The crust also consists of two layers are sial and sima layers.