NCERT Summary: The Himalayas | Geography for UPSC CSE PDF Download

The Trans-Himalayas 

Karakoram Range

Ladakh Range

• The Ladakh Range is seen as an extension of the Karakoram Range towards the southeast.
• It stretches from the mouth of the Shyok River in North Kashmir towards the Indo-Tibetan borders.
• Occasionally, the Deosai Mountains in Pakistan-Occupied Kashmir (POK) and the Kailash Range in western Tibet are considered part of the Ladakh Range.

Zaskar Range

• The Zaskar Range runs roughly parallel to the Great Himalayan Range.
• Extending southeast from the Suru River to the upper Karnali River, it is characterized by its own unique features.
• The highest peak in this range is Kamet Peak, standing at 25,446 feet.

The Himalayan Ranges

• Composition: The Himalayan Range, the youngest mountain range globally, is primarily composed of uplifted sedimentary and metamorphic rocks.
• Boundaries: 
  • Bordered to the northwest by the Karakoram and Hindu Kush ranges, to the north by the Tibetan Plateau, and to the south by the Indo-Gangetic Plains.
  • While the southern boundary is well-defined by foothills, the northern boundary blends into the edge of the Tibetan Plateau.
• Extent: Spans over 2,400 kilometers from the Indus Gorge in the west to the Brahmaputra Gorge in the east.
• Width: Wider in the western side compared to the eastern side.
• Elevation:
  • Average elevation approximately 6,100 meters.
  • Western Himalayas show gradual elevation change, while the Eastern Himalayas exhibit rapid elevation changes.

Greater Himalayas (Himadri)

• Also known as Inner Himalayas or Central Himalayas.
• Composed of ancient rocks like granite, gneisses, and schist.
• Orientation varies across regions:
  • Extends southeast across northern Pakistan, India, and Nepal.
  • Curves eastwards across Sikkim and Bhutan.
  • Turns northeast across northern Arunachal Pradesh.
• Home to world's highest peaks including Nanga Parbat, Mount Everest, Kanchenjunga, and Namcha Barwa.
• Slopes steep towards the north and gentle towards the south.

• Also termed Lesser or Lower Himalayas.
• Mean elevation 3,500 to 5,000 meters, average width 60 to 80 kilometers.
• Prominent ranges: Nag Tibba, Mahabharat Range, Dhauladhar, Pir Panjal, and Mussoorie Range.
• Important rivers like Jhelum and Chenab traverse this region.
• Famous Valley of Kashmir lies between Pir Panjal and Zanskar range.
• Hosts hill resorts like Shimla, Chail, Ranikhet, Nainital, Almora.
• Formation of Karewas, fluvioglacial deposits, is notable.

Shiwalik or Outer Himalayas

• Southernmost range, lying between Middle Himalayas in the north and Indo-Gangetic Plains in the south.
• Rises abruptly from Indus and Ganges plains in the south, parallel to the main Himalayan Range in the north.
• Separated from the main range by valleys.
• Churia Range in Nepal.
• Formation of Doons and Duars: Upliftments halted river flow, forming temporary lakes. Sediments deposited formed fertile alluvial soils, known as Doons in the west and Duars in the east, vital for tea cultivation.

The Eastern Hills or the Purvanchal

• The Himalayas take a sudden southward turn near the Dihang Gorge due to the Syntaxial Bend, giving rise to a series of relatively low hills known as the Purvanchal or Eastern Hills.
• Extending from Arunachal Pradesh in the north to Mizoram in the south, these hills serve as India’s border with Myanmar.

Prominent Ranges:

• Patkai Bum: Located along the boundary between Arunachal Pradesh and Myanmar, the Patkai Bum is the northernmost range of the Purvanchal.
• Naga Hills: South of Patkai Bum, the Naga Hills, along with Patkai Bum, form the watershed between India and Myanmar.
• Manipur Hills: Situated south of the Naga Hills, the Manipur Hills are separated from the Naga Hills by the Barail Range.
• Mizo Hills or Lushai Hills: Found to the south of the Manipur Hills, the Mizo Hills or Lushai Hills complete the series of hills in the Purvanchal region.