Rock Cycle

We see rocks in our surrounding, from different shapes to size. Rocks never remain same and they are always changing with time. Rock cycle is a basic concept in geology that describes the time-consuming transitions through geologic time.

Rocks are constantly being recycled and go through several processes of chemical and physical changes. There are three main rock types:

  • Sedimentary
  • Metamorphic
  • Igneous

As the diagram below shows that each type of rocks are altered or destroyed when it is forced out of its equilibrium conditions. These cycle of rock formation and wearing out is constantly recycled the earth’s minerals. The rock cycle is nothing but a process by which rocks of one type with certain characteristics changes into the rocks of another kind.

Rock Cycle

Rock Cycle: Transition to Igneous

When rocks are pushed deep under the earth’s surface, they may melt into magma. If the conditions no longer exist for the magma to stay in its liquid state, it will solidify into an igneous rock.

Rock Cycle: Transition to Metamorphic

The rock exposed to high temperatures and pressures can be changed physically or chemically to form a different rock, called metamorphic.

Rock Cycle: Transition to Sedimentary

Rocks exposed to the atmosphere are variable unstable and subject to the processes of weathering and erosion. This process breaks the original rock down into smaller fragments and carries away dissolved materials.

Practise This Question

Suppose you have three bodies A, B and C. A and B are at same temperature. When B and C are brought in contact, heat flows from C to B until flow of heat stops. What will happen when A and C are brought in contact?