Updated By: LatestGKGS Desk
Geography: Types of Rocks Igneous, Sedimentary and Metamorphic Rocks
Types of Rocks
The crust is composed of various types of rocks .
These rocks differ in appearance,colour and degree of denudation.
For the basic understanding of physical landforms of earth.
Rocks play an important role.
Rocks form the base of soil and also support the natural vegetation to some extent.
Rocks are of three types-
Igneous Rocks
Igneous rocks are formed by the cooled and solidified magma. These are crystalline in structure.
Igneous rocks do not contain fossils. These contain greater deposition of basic oxides.
For Example: Aluminium , Magnesium and Iron.
These are dark in colour.
There are two types of igneous rocks-
1) Plutonic Rocks
2) Volcanic Rocks
Sedimentary Rocks
Sedimentary rocks are made up of sediments.
They differ in layer formation from the other rocks.
These rocks are fine grained like sediments , and may be soft or hard.
These are non-crystalline in structure.
Sedimentary rocks contain fossils.
These sediments are brought by the glaciers,streams or wind.
Metamorphic Rocks
Metamorphic rocks are the transformation of igneous or sedimentary.
The rocks get transfromed into another rock under great heat and pressure.
For example:
Clay is transformed into Slate.
Limestone is transformed into Marble.
Sandstone is transformed into Quartzite.
Coal is transformed into Graphite.
