What is Rock Cycle?
Rock cycle is the process in which different types of rocks are slowly but continually changing from one to another, again and again. This change forms a cycle known as “Rock Cycle”. The change in their form is the result of Earth’s internal heat, pressure and effects of natural (wind, water or gravity) or human activities.
Rocks
Rocks can be made of minerals that are made by living
organisms with chemical composition and crystal like structures. They can also
be made by the pieces of other rocks. The elements by which rocks are made, are
never created or destroyed. Instead, they are recycled repeatedly.
Types of Rocks
There are different types of rocks that are formed in different
environments of the Earth (above or below the Earth’s surface).
Igneous
The word ”igneous” is derived from the Latin word which means ‘fire”. These rocks are formed when magma cools and either hardens slowly in the underground or quickly if it erupts from volcanoes. (Example: Granite).
Sedimentary
Sedimentary rocks are actually the pieces of other rocks.
These rocks are fairly soft and break apart or crumble easily. (Examples: clay,
coal or chalk).
Metamorphic
The word “metamorphism” is derived from the Greek word, which means “change of form”. They are formed under the Earth’s surface. When the
changes occur in their original shape, due to high heat and pressure. (Examples: slate or marble.
Steps of Rock Cycle
The cycle is depended on different factors (temperature,
pressure, time) and changes in environment of Earth’s crust and its surface.
1) Formation of Igneous Rock:
Magma from deep inside the earth, solidifies in the surface due to cooling and become igneous rocks. Now these rocks cool down on the surface.
2) Formation of Sedimentary Rock:
Because of weathering and
erosional activities, the igneous rocks are broken down to form sediments and
pressed together for long periods to form sedimentary rocks.
3) Formation of Metamorphic Rocks
After very long time, these
sedimentary and igneous rocks end up being buried deep underground the
soil. These rocks are exposed to intense
heat and pressure, which change them into metamorphic rock.
4) Weathering
Now there rocks present on the
surface of the earth, are continually being broken down by wind and water over
a long time.
5) Transportation
The rocks are then carried away by
rain, streams, rivers, and oceans to a different place from their origin.
6) Deposition
During the carriage of rocks by
rivers, the rock particles sink and become a layer of sediment, which convert
into sedimentary rock after some time.
Melting of underground metamorphic rock forms magma, which on crystallization forms igneous rock, and the cycle repeated.