(ii) Himachal and Uttaranchal Himalayas
Figure Himalayan Mountain Complex: Cross Sectional View from South to North
Great Himalaya or Himadri
- Northern most range is known as the Great or Inner Himalayas or the ‘Himadri’.
- ‘Himadri’. It is the most continuous rangeconsisting of the loftiest peaks with an average height of 6,000 metres.
- The folds of Great Himalayas areasymmetrical in nature.
- The core of this part of Himalayas iscomposed of granite.
- It is perennially snow bound, and a number of glaciers descend from this range. The Himalayan Mountains are divided into three main parallel ranges.
- In the Great Himalayan range, the valleys are mostly inhabited by the Bhotia’s.
- These are nomadic groups who migrate to ‘Bugyals’ (the summer glasslands in the higher reaches) during summer months and return to the valleys during winters.
Himachal or lesser Himalaya
- Therange lying to the south of the Himadri forms the most rugged mountain system and is known as Himachal or lesser Himalaya.
- The altitudevaries between 3,700 and 4,500 metres and the average width is of 50 Km.
- The Pir Panjal range forms the longest and the most important range
- The Dhaula Dharand the Mahabharat ranges are also prominent ones.
- This range consists of the famous valley of Kashmir, the Kangra and Kullu Valley in Himachal Pradesh.
- This region is well known for its hill stations
- The outer most range of the Himalayas is called the Shiwaliks.
- They extend over a width of 10-50 Km and have an altitude varying between 900 and 1100 metres.
- These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges located farther north.
- Covered with thick gravel called Alluvium.
- The longitudinal valley lying between lesser Himalaya and the Shiwaliks are known asDuns.
- Dehra Dun, Kotli Dun and Patli Dun are some of the well-known Duns.
- The word shiwalik has its origin in the geological formation found in and around a place called Sivawala near Dehra Dun
- Which was once a headquarter of the Imperial Survey and which subsequently established its permanent headquarters at Dehra Dun.
- Dehra Dun is the largest of all the duns with an approximate length of 35-45 km and a width of 22-25 km.
Some of the important hill stations
The cantonment towns and health resorts
The two distinguishing features of this region
- The ‘Shiwalik
- ‘Dun formations’
Some important duns
- Chandigarh-Kalka dun
- Nalagarh dun
- Dehra Dun
- Harike dun
- The Kota dun
(iii)The Darjeeling and Sikkim Himalayas
- They are flanked by Nepal Himalayas in the west and Bhutan Himalayas in the east.
- It is relatively small but is a most significant part
- Known for its fast-flowing Rivers such as Tista
- It is a region of high mountain peaks likeKanchenjunga (Kanchengiri), and deep valleys.
- The higher reaches of this region areinhabited by Lepcha tribes while the southern part, particularly the Darjiling Himalayas, has a mixed population of Nepalis, Bengalis and tribals from Central India.
- The British, taking advantage of the physical conditions such as
- Moderate slope
- Thick soil cover
- High organic content
- Well distributed rainfall throughout the year
- And mild winters,
- Introduced tea plantations
- In place of the Shiwaliks here, the‘duar formations’ are important
- Which have also been used for the development of tea gardens