Himalayas: Formation of Himalayas

Formation

• Himalayas are the outcome of a collision between the Indian plate and the Eurasian plate. 
• During the Cretaceous period, the Indian peninsula broke away from Gondwana and started its northward journey. The Tethys present between the two plates got squeezed forming a geosyncline.
• As the plate moved northwards, the oceanic margin of the Indian plate got subducted which led to volcanism, and part of these rocks are preserved in the Ladakh region.

Stages of the Formation of Himalayas

1. Phase 1 
   • During the Cretaceous Period,  the Indian plate moved over the reunion hotspot.
   • The movement of the plate attained its mass velocity as it was closer to the equator and squeezing of the Tethys started towards the end of the Paleocene.
2. Phase 2 
   • The northwestern part of the Indian plate hit the Eurasian plate leading to the formation of potwar plateau, after which the plate took an anti-clockwise turn, so the eastern part of the plate collision created the Eastern Himalayas.
3. Phase 3
   • Continued northward movement and further compression of the Tethys Sea led to the rising of the Tethian Himalayas.
4. Phase 4
   • Mountains continued to converge, creating fold mountains known as the Main Himalayas or Greater Himalayas, and south of them, the Main Central Thrust was formed.
   • The Main Boundary Fault line was formed south of the Lesser Himalayas, sometimes known as the Middle Himalayas, as the process progressed.
5. Phase 5
   • Foredeep (deep depression) was formed on the foothills of the Greater and Lesser Himalayas, where deposition and subsequent compression resulted in the construction of the Shivalik Mountains. A new fault line that occurred south of it is known as the Himalayan Frontal Fault.