1. The Himalayas
- The Himalayas are young fold mountains of tertiary period which were folded over Tethys Sea due to intercontinental collision.
- These Himalayas extend about 2500 km between Indus and Brahmaputra gorges from west to east in an arc shaped manner.
- The upliftment of Himalayas is believed to have taken place in three main phases after upliftment of Karakoram and associated ranges during cretaceous period.
- The first and oldest phase is formation of Inner Himalayas (formed during Oligocene period). The second phase led to formation of Middle Himalayas (miocene period). The third and latest phase was formation of Outer Himalayas (post-pilocene period).
1.1 Outer Himalaya
- Outer Himalaya Vedic name is Siwalik. It is youngest and lowest range of Himalaya. The height of this range varies between 600 m to 1500 m, but rarely exceeds 650 m.
- Siwaliks are characterized by fault scraps, anticlinal crests and synclinical hills.
Important Hills of Siwalik Range
- Dalfa , Miri, Mishmi, Abor and Patkai in Arunachal Pradesh.
- Dhang range, Dundwa range, Churian and Muria Ghats in Nepal.
- Jammu hills in Jammu & Kashmir.
1.2 Middle Himalaya or Lesser Himalaya
- The Middle Himalaya forms the most intricate and rugged mountainous system, it is 60-80 km wide and 3700-4500m high. Its Vedic name is Himachal.
- Most of the hills stations such as Dalhousie, Manali, Shimla, Nanital, Musoorie, Darjeeling, etc. are located in this range.
- On Dhauladhar range, the hill stations of Shimla and Pir Panjal are Situated. The Kashmir valley which is about 150 km long and 80 km wide lies between the Pir Panjal and the Zaskar ranges.
- From west to east, middle Himalaya is divided into following ranges:
- Pirpanjal range (J&K): It is longest range of the Middle Himalaya.
- Dhauladhar range (Himachal Pradesh)
- Mussoorie range (Uttarakhand)
- Nagtibba range (Uttarakhand)
- Mahabharat range (Nepal)
1.3 Inner Himalaya or Greater Himalaya
- Inner Himalaya or greater Himalaya Vedic names are Himadri & Bahirgiri. It is the highest mountain range of the world. Its average height is 6100 m. Most of the world’s highest peaks are located in this Inner Himalayan region.
Important Peaks in Inner Himalaya
- Mount Everest (8848 m): Mount Everest is the highest peak in the world. It is located in Nepal. It is also known as Sagarmatha in Nepal and Chomolangma in China.
- Mount K-2 (8611 m): It is also known as Godwin Austin or Qagir. It is the highest peak of India and 2nd highest peak of the world. It is located in Pakistan Occupied Kashmir in Karakoram range.
- Mount Kanchenjunga (8598 m): It is the 2nd highest peak of India and third highest peak of the world. It is located in Sikkim region.
Hills of North Eastern States in India
- Arunachal Pradesh : Dafla hills, Mishmi hills, Miri hills, abor hills and Patkai hills.
- Nagaland : Naga hills
- Assam : Mikkir hills
- Mizoram : mizo or Lushai hills
- Meghalaya : Garo, Khasi and Jaintia hills.
2. Trans Himalaya
- Trans Himalaya region lies behind Himalayas (mainly in western part of Himalayas) in Jammu and Kashmir and it comprises of Karakoram, Ladakh & Zaskar range. It includes lofty peaks and big glaciers such as Sachin, Baltaro, Biafo and Hispar, etc.
- These ranges have been found even before the formation of Himalayas.
- The highest peak of Karakoram range is Mount K-2 (8611 m) which is also known as Godwin-Austin or Qagir. The other important peak of this range is Hidden peak (8068 m).
- The Kailash range is an offshoot of the Ladakh range. Its average elevation is 5500 to 6000 m. The highest peak of Kailash range is Mount Kailash.